'S e seòrsa de chreig theinnteach a th' ann an clach-ghràin a thathas a' cladhach airson a neart, a dùmhlachd, a sheasmhachd agus a sheasamh an aghaidh creimeadh. Ach tha clach-ghràin cuideachd glè ioma-chruthach - chan ann dìreach airson ceàrnagan agus ceart-cheàrnagan a tha e! Gu dearbh, bidh sinn ag obair le misneachd le co-phàirtean clach-ghràin air an innleadaireachd ann an cumaidhean, ceàrnan agus lùban de gach seòrsa gu cunbhalach - le toraidhean sàr-mhath.
Through our state of the art processing, cut surfaces can be exceptionally flat. These qualities make granite the ideal material to create custom-size and custom-design machine bases and metrology components. Granite is:
■ innealaichte
■ rèidh gu mionaideach nuair a thèid a ghearradh agus a chrìochnachadh
■ dìonach bho mheirg
■ seasmhach
■ maireannach
Tha pàirtean clach-ghràin furasta an glanadh cuideachd. Nuair a bhios tu a’ cruthachadh dhealbhaidhean gnàthaichte, bi cinnteach gun tagh thu clach-ghràin air sgàth a bhuannachdan àrd-inbhe.

INBHEAN / TAGRAIDHEAN ÀRD-CHAITHEAMH
Tha susbaint àrd grian-chlach anns a’ chlach-ghràin a bhios ZHHIMG a’ cleachdadh airson ar toraidhean truinnsear uachdar àbhaisteach, a bheir barrachd dìon an aghaidh caitheamh is milleadh. Tha ìrean ìosal gabhail a-steach uisge aig na dathan Superior Black againn, a’ lughdachadh a’ chothruim gum meirg na tomhasairean mionaideach agad fhad ‘s a tha iad a’ suidheachadh air na truinnsearan. Bidh na dathan clach-ghràin a tha ZHHIMG a’ tabhann a’ leantainn gu nas lugha de dheàrrsadh, a tha a’ ciallachadh nas lugha de sgìths sùla dha daoine fa leth a bhios a’ cleachdadh nam truinnsearan. Tha sinn air na seòrsaichean clach-ghràin againn a thaghadh fhad ‘s a tha sinn a’ beachdachadh air leudachadh teirmeach ann an oidhirp an taobh seo a chumail cho ìosal ‘s as urrainn.

CUSTOM APPLICATIONS
Nuair a bhios feum agad air truinnsear le cumaidhean gnàthaichte, cuir-a-steach snàthaichte, sliotan no innealachadh eile airson an tagraidh agad, bidh thu airson stuth mar Black Jinan Black a thaghadh. Tha an stuth nàdarrach seo a’ tabhann stiffness nas fheàrr, maothachadh crith sàr-mhath, agus comas innealachaidh nas fheàrr.

Tha e cudromach a thoirt fa-near nach eil dath leis fhèin na chomharradh air feartan corporra na cloiche. San fharsaingeachd, tha dath clach-ghràin ceangailte gu dìreach ri làthaireachd no neo-làthaireachd mhèinnirean, agus is dòcha nach eil buaidh sam bith aca air na feartan a tha a’ dèanamh stuth math airson truinnsearan uachdar. Tha clach-ghràin pinc, liath is dubh ann a tha sàr-mhath airson truinnsearan uachdar, a bharrachd air clach-ghràin dubh, liath is pinc nach eil freagarrach airson cleachdaidhean mionaideach. Chan eil feartan deatamach clach-ghràin, a thaobh a chleachdadh mar stuth truinnsear uachdar, co-cheangailte ri dath, agus tha iad mar a leanas:
■ Doilleireachd (lùbadh fo luchd - air a chomharrachadh le Modúl Leaisteachd)
■ Cruas
■ Dlùths
■ Seasmhachd caitheamh
■ Seasmhachd
■ Porachd

Tha sinn air mòran stuthan clach-ghràin a dhearbhadh agus coimeas a dhèanamh eatorra. Mu dheireadh fhuair sinn an toradh, gur e clach-ghràin dhubh Jinan an stuth as fheàrr a tha fios againn a-riamh. Tha clach-ghràin dhubh Innseanach agus clach-ghràin Afraga a Deas coltach ri clach-ghràin dhubh Jinan, ach tha na feartan corporra aca nas miosa na clach-ghràin dhubh Jinan. Cumaidh ZHHIMG orra a’ coimhead airson barrachd stuthan clach-ghràin san t-saoghal agus a’ dèanamh coimeas eadar na feartan corporra aca.

Gus barrachd bruidhinn mun chlach-ghràin a tha ceart airson do phròiseict, cuir fios thugainninfo@zhhimg.com.

Bidh diofar luchd-saothrachaidh a’ cleachdadh diofar inbhean. Tha mòran inbhean air feadh an t-saoghail.
Inbhe DIN, ASME B89.3.7-2013 no Sònrachadh Feadarail GGG-P-463c (Pleitean Uachdar Granite) agus mar sin air adhart mar bhunait airson na sònrachaidhean aca.

Agus is urrainn dhuinn truinnsear sgrùdaidh mionaideachd clach-ghràin a dhèanamh a rèir do riatanasan. Fàilte fios a chur thugainn ma tha thu airson tuilleadh fiosrachaidh fhaighinn mu barrachd inbhean.

Faodar beachdachadh air rèidhleanachd mar a h-uile puing air an uachdar a bhith taobh a-staigh dà phlèana co-shìnte, plèana a’ bhunait agus plèana a’ mhullaich. Is e tomhas an astair eadar na plèanaichean rèidhleanachd iomlan an uachdair. Mar as trice bidh fulangas aig an tomhas rèidhleanachd seo agus faodaidh e comharrachadh ìre a ghabhail a-steach.

Mar eisimpleir, tha fulangas rèidh airson trì ìrean àbhaisteach air am mìneachadh anns an t-sònrachadh feadarail mar a tha air a dhearbhadh leis an fhoirmle a leanas:
■ Ìre Obair-lann AA = (40 + ceàrnag trastanach/25) x .000001" (aon-thaobhach)
■ Ìre Sgrùdaidh A = Ìre Obair-lann AA x 2
■ Seòmar Innealan Ìre B = Obair-lann Ìre AA x 4.

Airson pleitean uachdar de mheud àbhaisteach, tha sinn a’ gealltainn fulangas rèidh a tha nas àirde na riatanasan an t-sònrachaidh seo. A bharrachd air rèidh, tha ASME B89.3.7-2013 & Sònrachadh Feadarail GGG-P-463c a’ dèiligeadh ri cuspairean a’ gabhail a-steach: cruinneas tomhais ath-aithris, feartan stuthan clach-ghràin pleitean uachdar, crìochnachadh uachdar, suidheachadh puing taic, stiffness, dòighean sgrùdaidh iomchaidh, stàladh cuir-a-steach snàthaichte, msaa.

Bidh pleitean uachdar clach-ghràin ZHHIMG agus pleitean sgrùdaidh clach-ghràin a’ coinneachadh ri no a’ dol thairis air na riatanasan uile a tha air an cur a-mach san t-sònrachadh seo. Aig an àm seo, chan eil sònrachadh mìneachaidh ann airson pleitean ceàrn clach-ghràin, co-shìntean, no ceàrnagan maighstir.

Agus gheibh thu na foirmlean airson inbhean eile ann anLuchdaich a-nuas.

An toiseach, tha e cudromach am plàta a chumail glan. Mar as trice, is e duslach sgrìobach san adhar an adhbhar as motha airson caitheamh is deòir air plàta, oir bidh e buailteach a dhol a-steach do phìosan obrach agus uachdar conaltraidh nan tomhais. San dàrna àite, còmhdaich am plàta agad gus a dhìon bho dhuslach is milleadh. Faodar beatha caitheamh a leudachadh le bhith a’ còmhdach a’ phlàta nuair nach eilear ga cleachdadh, le bhith a’ tionndadh a’ phlàta bho àm gu àm gus nach tèid cus cleachdaidh a dhèanamh air aon raon, agus le bhith a’ cur padaichean conaltraidh stàilinn an àite padaichean carbide air na tomhasan. Cuideachd, seachain biadh no deochan bog a chuir air a’ phlàta. Thoir an aire gu bheil searbhag carbonach no fosfarach ann am mòran dheochan bog, a dh’ fhaodas na mèinnirean nas buige a sgaoileadh agus claisean beaga fhàgail san uachdar.

Tha seo an urra ri mar a thathar a’ cleachdadh a’ phlàta. Ma ghabhas e dèanamh, tha sinn a’ moladh a’ phlàta a ghlanadh aig toiseach an latha (no na shift obrach) agus a-rithist aig a’ cheann thall. Ma dh’fhàsas a’ phlàta salach, gu h-àraidh le lionntan olach no steigeach, bu chòir a glanadh sa bhad.

Glan am plàta gu cunbhalach le leaghan no inneal-glanaidh uachdar plàta gun uisge ZHHIMG. Tha an roghainn de fhuasglaidhean glanaidh cudromach. Ma thèid fuasglaiche luaineach a chleachdadh (acetone, tanaichear lacair, deoch làidir, msaa.) bidh an falmhachadh a’ fuarachadh an uachdair, agus ga shaobhadh. Anns a’ chùis seo, feumar leigeil leis a’ phlàta tilleadh gu àbhaisteach mus tèid a chleachdadh air neo tachraidh mearachdan tomhais.

Bidh an ùine a dh’ fheumar airson a’ phlàta a thighinn gu àbhaisteach ag atharrachadh a rèir meud a’ phlàta, agus na tha de fhuarachadh ann. Bu chòir uair a thìde a bhith gu leòr airson phlàtaichean nas lugha. Is dòcha gum bi feum air dà uair a thìde airson phlàtaichean nas motha. Ma thèid inneal-glanaidh stèidhichte air uisge a chleachdadh, bidh beagan fuarachaidh le gal ann cuideachd.

Cumaidh am plàta an t-uisge cuideachd, agus dh’ fhaodadh seo meirg adhbhrachadh air pàirtean meatailt a bhios a’ conaltradh ris an uachdar. Fàgaidh cuid de ghlanadairean fuigheall steigeach às deidh dhaibh tiormachadh, a tharraingeas duslach san adhar, agus a mheudaicheas caitheamh, seach a lughdachadh.

Tha seo an urra ri cleachdadh agus àrainneachd a’ phlàta. Tha sinn a’ moladh gun tèid ath-chalabrachadh iomlan a dhèanamh air plàta ùr no air goireas clach-ghràin mionaideach taobh a-staigh bliadhna bho cheannach. Ma thèid am plàta uachdar clach-ghràin a chleachdadh gu mòr, is dòcha gum biodh e ciallach an t-àm seo a ghiorrachadh gu sia mìosan. Seallaidh sgrùdadh mìosail airson mearachdan tomhais a-rithist le bhith a’ cleachdadh ìre dealanach, no inneal coltach ris, spotan caitheamh sam bith a tha a’ leasachadh agus cha toir e ach beagan mhionaidean a dhèanamh. Às deidh toraidhean a’ chiad ath-chalabrachaidh a dhearbhadh, faodar an t-àm calabrachaidh a leudachadh no a ghiorrachadh mar a tha ceadaichte no riatanach leis an t-siostam càileachd a-staigh agad.

Is urrainn dhuinn seirbheis a thabhann gus do chuideachadh le bhith a’ sgrùdadh agus a’ calabrachadh do phlàta uachdar clach-ghràin.

Tha grunn adhbharan a dh’ fhaodadh a bhith ann airson eadar-dhealachaidhean eadar calibrations:

• Chaidh an uachdar a nighe le fuasgladh teth no fuar mus deach a chalabrachadh, agus cha deach ùine gu leòr a thoirt dha airson a bhith air a dhèanamh àbhaisteach
• Tha taic neo-iomchaidh aig a’ phlàta
• Atharrachadh teòthachd
• Dreachan
• Solas dìreach na grèine no teas rèididh eile air uachdar a’ phlàta. Dèan cinnteach nach eil solais os cionn a’ teasachadh an uachdair.
• Caochlaidhean anns a’ chlaonadh teòthachd dhìreach eadar a’ gheamhradh agus an samhradh (Ma ghabhas e dèanamh idir, bi fios agad dè an teòthachd claonadh dhìreach a th’ ann aig an àm a thèid an calabrachadh a dhèanamh.)
• Cha deach ùine gu leòr a thoirt don phlàta airson a dhol à bith às dèidh a chuir air falbh
• Cleachdadh mì-iomchaidh uidheam sgrùdaidh no cleachdadh uidheam nach deach a chalabrachadh
• Atharrachadh uachdar mar thoradh air caitheamh

Cia mheud seòrsa toll a tha air clach-ghràin mionaideach?

Sliotan air Co-phàirtean Granite Mionaideach

Airson mòran fhactaraidhean, seòmraichean sgrùdaidh agus deuchainn-lannan, thathas an urra ri pleitean uachdar clach-ghràin mionaideach mar bhunait airson tomhas ceart. Leis gu bheil a h-uile tomhas loidhneach an urra ri uachdar iomraidh ceart às a bheil na tomhasan deireannach air an toirt, bidh pleitean uachdar a’ toirt seachad am plèana iomraidh as fheàrr airson sgrùdadh agus cruth obrach mus tèid innealachadh a dhèanamh. Tha iad cuideachd nan bunaitean air leth freagarrach airson tomhasan àirde a dhèanamh agus uachdaran a thomhas. A bharrachd air an sin, tha ìre àrd de rèidhleanachd, seasmhachd, càileachd iomlan agus obair-ciùird gan dèanamh nan deagh roghainn airson siostaman tomhais meacanaigeach, dealanach agus optigeach sòlaimte a chuir suas. Airson gin de na pròiseasan tomhais sin, tha e riatanach pleitean uachdar a chumail air an calabrachadh.

Repeat Measurements and Flatness

Tha an dà chuid rèidheachd agus ath-thomhasan deatamach gus dèanamh cinnteach à uachdar mionaideach. Faodar rèidheachd a mheas mar a h-uile puing air an uachdar a bhith taobh a-staigh dà phlèana co-shìnte, plèana a’ bhunait agus plèana a’ mhullaich. Is e tomhas an astair eadar na plèanaichean rèidheachd iomlan an uachdair. Mar as trice bidh fulangas aig a’ thomhas rèidheachd seo agus faodaidh e comharrachadh ìre a ghabhail a-steach.

The flatness tolerances for three standard grades are defined in the federal specification as determined by the following formula:

Inbhe DIN, Inbhe GB, Inbhe ASME, inbhe JJS ... dùthaich eadar-dhealaichte le diofar sheasamh ...

Tuilleadh fiosrachaidh mun inbhe.

In addition to flatness, repeatability must be ensured. A repeat measurement is a measurement of local flatness areas. It is a measurement taken anywhere on the surface of a plate that will repeat within the stated tolerance. Controlling local area flatness to a tighter tolerance than overall flatness guarantees a gradual change in surface flatness profile, thereby minimizing local errors.

Gus dèanamh cinnteach gu bheil truinnsear uachdar a’ coinneachadh ris na sònrachaidhean airson rèidhleanachd agus ath-thomhas, bu chòir do luchd-saothrachaidh truinnsearan uachdar clach-ghràin Sònrachadh Feadarail GGG-P-463c a chleachdadh mar bhunait airson na sònrachaidhean aca. Tha an inbhe seo a’ dèiligeadh ri cruinneas ath-thomhas, feartan stuthan truinnsear uachdar clach-ghràin, crìochnachadh uachdar, suidheachadh puing taic, stiffness, dòighean sgrùdaidh iomchaidh agus stàladh cuir-a-steach snàthaichte.

Checking Plate Accuracy

Le bhith a’ leantainn beagan stiùiridhean sìmplidh, bu chòir tasgadh ann am plàta uachdar clach-ghràin mairsinn airson iomadh bliadhna. A rèir cleachdadh a’ phlàta, àrainneachd na bùtha agus an cruinneas a tha a dhìth, bidh tricead sgrùdadh cruinneas a’ phlàta uachdar ag atharrachadh. Is e riaghailt choitcheann gum faigh plàta ùr ath-chothromachadh iomlan taobh a-staigh bliadhna bho cheannach. Ma thèid am plàta a chleachdadh gu tric, thathar a’ moladh an ùine seo a ghiorrachadh gu sia mìosan.

Before a surface plate has worn beyond specification for overall flatness, it will show worn or wavy posts. Monthly inspection for repeat measurement errors using a repeat reading gage will identify wear spots. A repeat reading gage is a high-precision instrument that detects local error and can be displayed on a high magnification electronic amplifier.

An effective inspection program should include regular checks with an autocollimator, providing actual calibration of overall flatness traceable to National Institute of Standards and Technology (NIST). Comprehensive calibration by the manufacturer or an independent company is necessary from time to time.

Variations Between Calibrations

Ann an cuid de chùisean, bidh caochlaidhean ann eadar calabraidhean truinnsearan uachdar. Aig amannan faodaidh factaran leithid atharrachadh uachdar mar thoradh air caitheamh, cleachdadh ceàrr uidheamachd sgrùdaidh no cleachdadh uidheamachd neo-chalabraichte na caochlaidhean sin a mhìneachadh. Ach, is e teòthachd agus taic an dà fhactar as cumanta.

One of the most important variables is temperature. For instance, the surface might have been washed with a hot or cold solution prior to calibration and not allowed sufficient time to normalize. Other causes of temperature change include drafts of cold or hot air, direct sunlight, overhead lighting or other sources of radiant heat on the surface of the plate.

There also can be variations in the vertical temperature gradient between winter and summer. In some cases, the plate is not allowed sufficient time to normalize after shipment. It is a good idea to record the vertical gradient temperature at the time the calibration is performed.

Another common cause for calibration variation is a plate that is improperly supported. A surface plate should be supported at three points, ideally located 20% of the length in from the ends of the plate. Two supports should be located 20% of the width in from the long sides, and the remaining support should be centered.

Only three points can rest solidly on anything but a precision surface. Attempting to support the plate at more than three points will cause the plate to receive its support from various combinations of three points, which will not be the same three points on which it was supported during production. This will introduce errors as the plate deflects to conform to the new support arrangement. Consider using steel stands with support beams designed to line up with the proper support points. Stands for this purpose are generally available from the surface plate manufacturer.

If the plate is properly supported, precise leveling is only necessary if an application specifies it. Leveling is not necessary to maintain the accuracy of a properly supported plate.

Extend Plate Life

Le bhith a’ leantainn beagan stiùiridhean lughdaichidh sin caitheamh air truinnsear uachdar clach-ghràin agus mu dheireadh, leudaichidh e a bheatha.

An toiseach, tha e cudromach am plàta a chumail glan. Mar as trice, is e duslach sgrìobach san adhar an adhbhar as motha airson caitheamh is deòir air plàta, oir bidh e buailteach a dhol a-steach do phìosan obrach agus uachdar conaltraidh nan tomhais.

It also is important to cover plates to protect it from dust and damage. Wear life can be extended by covering the plate when not in use.

Cuairtich am plàta bho àm gu àm gus nach tèid cus cleachdaidh a dhèanamh air aon raon. Cuideachd, thathar a’ moladh padaichean conaltraidh stàilinn a chur an àite padaichean carbide air innealan-tomhais.

Avoid setting food or soft drinks on the plate. Many soft drinks contain either carbonic or phosphoric acid, which can dissolve the softer minerals and leave small pits in the surface.

Where to Relap

Nuair a dh’fheumas uachdar pleit clach-ghràin ath-uachdarachadh, smaoinich am bu chòir an t-seirbheis seo a dhèanamh air an làrach no aig an goireas calabrachaidh. Tha e an-còmhnaidh nas fheàrr am pleit ath-leapadh aig an fhactaraidh no aig goireas sònraichte. Ach, mura h-eil am pleit air a chaitheamh ro dhona, mar as trice taobh a-staigh 0.001 òirleach den fhulangas a tha a dhìth, faodar ath-uachdarachadh air an làrach. Ma tha pleit air a chaitheamh chun na h-ìre far a bheil e barrachd air 0.001 òirleach a-mach à fulangas, no ma tha e air a phutadh no air a sgàineadh gu dona, bu chòir a chur chun fhactaraidh airson a bleith mus tèid ath-leapadh.

A calibration facility has the equipment and factory setting providing the optimum conditions for proper plate calibration and rework if necessary.

Bu chòir a bhith faiceallach nuair a thaghas tu teicneòlaiche calabrachaidh is ath-uachdarachaidh air an làrach. Iarr teisteanas agus dearbhaich gu bheil calabrachadh ri lorg aig an uidheamachd a chleachdas an teicneòlaiche. Tha eòlas na fheart cudromach cuideachd, oir bheir e iomadh bliadhna ionnsachadh mar a nì thu lapadh ceart air clach-ghràin mhionaideach.

Critical measurements start with a precision granite surface plate as a baseline. By ensuring a reliable reference by using a properly calibrated surface plate, manufacturers have one of the essential tools for reliable measurements and better quality parts.Q

Checklist for Calibration Variations

1. Chaidh an uachdar a nighe le fuasgladh teth no fuar mus deach a chalabrachadh agus cha deach ùine gu leòr a thoirt dha gus a dhèanamh àbhaisteach.

2. Chan eil taic iomchaidh aig a’ phlàta.

3. Atharrachadh teòthachd.

4. Dreachan.

5. Solas dìreach na grèine no teas rèididh eile air uachdar a’ phlàta. Dèan cinnteach nach eil solais os cionn a’ teasachadh an uachdair.

6. Caochlaidhean anns a’ chlaonadh teòthachd dhìreach eadar a’ gheamhradh agus an samhradh. Ma ghabhas e dèanamh idir, bi fios agad dè an teòthachd claonadh dhìreach a th’ ann aig an àm a thèid an calabrachadh a dhèanamh.

7. Cha deach ùine gu leòr a thoirt don phlàta gus a h-uile càil atharrachadh às dèidh a chur air falbh.

8. Cleachdadh mì-iomchaidh uidheam sgrùdaidh no cleachdadh uidheam neo-chalabraichte.

9. Atharrachadh uachdar mar thoradh air caitheamh.

Tech Tips

• Leis gu bheil a h-uile tomhas loidhneach an urra ri uachdar iomraidh ceart às a bheil na tomhasan deireannach air an toirt, bidh pleitean uachdar a’ toirt seachad am plèana iomraidh as fheàrr airson sgrùdadh agus cruth obrach mus tèid innealachadh a dhèanamh.
• Controlling local area flatness to a tighter tolerance than overall flatness guarantees a gradual change in surface flatness profile, thereby minimizing local errors.
• Bu chòir do phrògram sgrùdaidh èifeachdach sgrùdaidhean cunbhalach a thoirt a-steach le autocollimator, a’ toirt seachad calabrachadh fìor air rèidhleanachd iomlan a ghabhas lorg chun Ùghdarras Sgrùdaidh Nàiseanta.

Am measg nam mìrean mèinnearach a tha a’ dèanamh suas clach-ghràin, tha còrr is 90% dhiubh nan feldspar agus grian-chlach, agus is e feldspar a’ mhòr-chuid dhiubh. Bidh am feldspar gu tric geal, liath is dearg-fheòil, agus tha a’ mhòr-chuid gun dath no geal liath-liath aig a’ ghrian-chlach, agus is iad sin prìomh dhath a’ chlach-ghràin. Tha feldspar agus grian-chlach nan mèinnirean cruaidh, agus tha e duilich an gluasad le sgian stàilinn. A thaobh nan spotan dorcha anns a’ chlach-ghràin, gu h-àraidh mica dubh, tha cuid de mhèinnirean eile ann. Ged a tha biotite caran bog, chan eil a chomas seasamh an aghaidh cuideam lag, agus aig an aon àm tha beagan dhiubh ann an clach-ghràin, gu tric nas lugha na 10%. Is e seo an suidheachadh stuthan anns a bheil clach-ghràin gu sònraichte làidir.

Is e adhbhar eile airson gu bheil clach-ghràin làidir gu bheil na mìrean mèinnearach aice ceangailte gu teann ri chèile agus air an leabachadh a-steach dha chèile. Gu tric bidh na pores a’ dèanamh suas nas lugha na 1% de mheud iomlan na creige. Tha seo a’ toirt don chlach-ghràin comas seasamh ri cuideaman làidir agus chan eil taiseachd a’ dol a-steach ann gu furasta.

Tha co-phàirtean clach-ghràin air an dèanamh de chlach gun meirg, searbhag agus alcalan, deagh sheasamh caitheamh agus beatha seirbheis fhada, gun chumail suas sònraichte. Bithear a’ cleachdadh co-phàirtean mionaideachd clach-ghràin sa mhòr-chuid ann an innealan gnìomhachas an inneil. Mar sin, canar co-phàirtean mionaideachd clach-ghràin no co-phàirtean clach-ghràin riutha. Tha feartan cho-phàirtean mionaideachd clach-ghràin gu bunaiteach mar an ceudna ri feartan àrd-ùrlaran clach-ghràin. Ro-ràdh do innealan agus tomhas cho-phàirtean mionaideachd clach-ghràin: Tha teicneòlas innealachaidh mionaideachd agus meanbh-innealachaidh nan stiùiridhean leasachaidh cudromach ann an gnìomhachas saothrachaidh innealan, agus tha iad air a bhith nan comharradh cudromach airson ìre àrd-theicneòlais a thomhas. Tha leasachadh teicneòlais ùr-nodha agus gnìomhachas an dìon do-sgaraichte bho theicneòlas innealachaidh mionaideachd agus meanbh-innealachaidh. Faodar co-phàirtean clach-ghràin a shleamhnadh gu rèidh anns an tomhas, gun stagnation. Tomhas uachdar obrach, chan eil sgrìoban coitcheann a’ toirt buaidh air cruinneas tomhais. Feumar co-phàirtean clach-ghràin a dhealbhadh agus a thoirt gu buil a rèir riatanasan taobh an iarrtas.

Raon tagraidh:

Mar a tha fios againn uile, tha barrachd is barrachd innealan is uidheamachd a’ taghadh phàirtean clach-ghràin mionaideach.

Bithear a’ cleachdadh phàirtean clach-ghràin airson gluasad fiùghantach, motaran loidhneach, cmm, cnc, inneal laser...

fàilte fios a chur thugainn airson tuilleadh fiosrachaidh.

Tha innealan-tomhais clach-ghràin agus co-phàirtean meacanaigeach clach-ghràin air an dèanamh de chlach-ghràin dhubh Jinan àrd-inbhe. Air sgàth an cruinneas àrd, an ùine fhada, an deagh sheasmhachd agus an aghaidh creimeadh, tha iad air a bhith air an cleachdadh barrachd is barrachd ann an sgrùdadh thoraidhean gnìomhachas an latha an-diugh agus raointean saidheansail leithid meacanaigeach, fànais, agus rannsachadh saidheansail.

Buannachdan

----Dà uair cho cruaidh ri iarann ​​​​tilgte;

----Tha atharrachaidhean beaga ann am meud mar thoradh air atharrachaidhean ann an teòthachd;

----Saor bho bhith a’ crathadh, agus mar sin chan eil bacadh air obair;

----Saor bho bhorran no stealladh air sgàth structar gràin mìn agus greamachd neo-shoilleir, a nì cinnteach à ìre àrd de rèidhleanachd thar beatha seirbheis fhada agus nach dèan milleadh air pàirtean no ionnstramaidean eile;

----Obrachadh gun trioblaid airson a chleachdadh le stuthan magnetach;

----Beatha fhada agus saor bho mheirg, agus mar thoradh air sin tha cosgaisean cumail suas ìosal.

Tha na pleitean uachdar clach-ghràin mionaideach air an lapadh gu mionaideach gu ìre àrd de rèidhleanachd gus cruinneas a choileanadh agus tha iad air an cleachdadh mar bhunait airson siostaman tomhais meacanaigeach, dealanach agus optigeach sòlaimte a chuir suas.

Seo cuid de na feartan sònraichte a tha aig truinnsear uachdar clach-ghràin:

Co-ionannachd ann an cruas;

Cumhachan ceart fo luchd;

Gabhail a-steach crith;

Furasta a ghlanadh;

An aghaidh pasgadh;

Porosity ìosal;

Neo-sgrìobach;

Neo-mhagnaiteach

Buannachdan Plàta Uachdar Granite

First, the rock after a long period of natural aging, uniform structure, coefficient minimum, the internal stress completely disappear, not deformed, so the precision is high.

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Precision Granite Base Can Improve Machine Tool Performances

Requirements are constantly increasing in mechanical engineering in general and in machine tool construction in particular. Achieving maximum precision and performance values without increasing costs are constant challenges to being competitive. The machine tool bed is a decisive factor here. Therefore, more and more machine tool manufacturers are relying on granite. Due to its physical parameters, it offers clear advantages that cannot be achieved with steel or polymer concrete.

Granite is a so-called volcanic deep rock and has a very dense and homogeneous structure with an extremely low coefficient of expansion, low thermal conductivity and high vibration damping.

Below you will discover why the common opinion that granite is mainly only suitable as machine base for high-end coordinate measuring machines is long outdated and why this natural material as a machine tool base is a very advantageous alternative to steel or cast iron even for high-precision machine tools.

We can manufacture granite components for dynamic motion, granite components for linear motors, granite components for ndt, granite components for xray, granite components for cmm, granite components for cnc, granite precision for laser, granite components for aerospace, granite components for precision stages...

High Added Value Without Additional Costs
The increasing use of granite in mechanical engineering is not so much due to the massive increase in the price of steel. Rather, it is because the added value for the machine tool achieved with a machine bed made of granite is possible at very little or no extra cost. This is proven by cost comparisons of well-known machine tool manufacturers in Germany and Europe.

The considerable gain in thermodynamic stability, vibration damping and long-term precision made possible by granite cannot be achieved with a cast iron or steel bed, or only at relatively high cost. For example, thermal errors can account for up to 75% of the total error of a machine, with compensation often attempted for by software – with moderate success. Due to its low thermal conductivity, granite is the better foundation for long-term precision.

With a tolerance of 1 μm, granite easily meets the flatness requirements according to DIN 876 for the degree of accuracy 00. With a value of 6 on the hardness scale 1 to 10, it is extremely hard, and with its specific weight of 2.8g/cm³ it almost reaches the value of aluminium. This also results in additional advantages such as higher feed rates, higher axis accelerations and an extension of the tool life for cutting machine tools. Thus, the change from a cast bed to a granite machine bed moves the machine tool in question into the high-end class in terms of precision and performance – at no extra cost.

Granite’s Improved Ecological Footprint
In contrast to materials such as steel or cast iron, natural stone does not have to be produced with a great deal of energy and using additives. Only relatively small amounts of energy are required for quarrying and surface treatment. This results in a superior ecological footprint, which even at the end of a machine’s life surpasses that of steel as a material. The granite bed can be the basis for a new machine or be used for completely different purposes such as shredding for road construction.

Nor are there any shortages of resources for granite. It is a deep rock formed from magma within the earth’s crust. It has ‘matured’ for millions of years and is available in very large quantities as a natural resource on almost all continents, including all of Europe.

Conclusion: The numerous demonstrable advantages of granite compared to steel or cast iron justify the increasing willingness of mechanical engineers to use this natural material as a foundation for high-precision, high-performance machine tools. Detailed information about granite properties, which are advantageous for machine tools and mechanical engineering, can be found in this further article.

A repeat measurement is a measurement of local flatness areas. The Repeat Measurement specification states that a measurement taken anywhere on the surface of a plate will repeat within the stated tolerance. Controlling local area flatness tighter than overall flatness guarantees a gradual change in surface flatness profile thereby minimizing local errors.

Most manufacturers, including imported brands, adhere to the Federal Specification of overall flatness tolerances but many overlook the repeat measurements. Many of the low value or budget plates available in the market today will not guarantee repeat measurements. A manufacturer who does not guarantee repeat measurements is NOT producing plates that meet the requirements of ASME B89.3.7-2013 or Federal Specification GGG-P-463c, or DIN 876, GB, JJS...

Both are critical to ensure a precision surface for accurate measurements. Flatness specification alone is not sufficient to guarantee measurement accuracy. Take as an example, a 36 X 48 Inspection Grade A surface plate, which meets ONLY the flatness specification of .000300". If the piece being checked bridges several peaks, and the gage being used is in a low spot, the measurement error could be the full tolerance in one area, 000300"! Actually, it can be much higher if the gage is resting on the slope of an incline.

Errors of .000600"-.000800" are possible, depending upon the severity of the slope, and the arm length of the gage being used. If this plate had a Repeat Measurement specification of .000050"F.I.R. then the measurement error would be less than .000050" regardless of where the measurement is taken on the plate. Another problem, which usually arises when an untrained technician attempts to resurface a plate on-site, is the use of Repeat Measurements alone to certify a plate.

The instruments that are used to verify repeatability are NOT designed to check overall flatness. When set to zero on a perfectly curved surface, they will continue to read zero, whether that surface is perfectly flat or perfectly concave or convex 1/2"! They simply verify the uniformity of the surface, not the flatness. Only a plate that meets both the flatness specification AND the repeat measurement specification truly meets the requirements of ASME B89.3.7-2013  or Federal Specification GGG-P-463c.

Ask us about or flatness specification and repeat measurement promise by calling +86 19969991659 or emailing INFO@ZHHIMG.COM

Yes, but they can only be guaranteed for a specific vertical temperature gradient. The effects of thermal expansion on the plate could easily cause a change in accuracy greater than the tolerance if there is a change in the gradient. In some cases, if the tolerance is tight enough, the heat absorbed from overhead lighting can cause enough of a gradient change over several hours.

Granite has a coefficient of thermal expansion of approximately .0000035 inches per inch per 1°F. As an example: A 36" x 48" x 8" surface plate has an accuracy of .000075" (1/2 of Grade AA) at a gradient of 0°F, the top and bottom are the same temperature. If the top of the plate warms up to the point where it is 1°F warmer than the bottom, the accuracy would change to .000275" convex ! Therefore, ordering a plate with a tolerance tighter than Laboratory Grade AA should only be considered if there is adequate climate control.

A surface plate should be supported at 3 points, ideally located 20% of the length in from the ends of the plate. Two supports should be located 20% of the width in from the long sides, and the remaining support should be centered. Only 3 points can rest solidly on anything but a precision surface.

The plate should be supported at these points during production, and it should be supported only at these three points while in use. Attempting to support the plate at more than three points will cause the plate to receive its support from various combinations of three points, which will not be the same 3 points on which it was supported during production. This will introduce errors as the plate deflects to conform to the new support arrangement. All zhhimg steel stands have support beams designed to line up with the proper support points.

If the plate is properly supported, precise leveling is only necessary if your application calls for it. Leveling is not necessary to maintain the accuracy of a properly supported plate.

Why Choose Granite for Machine Bases and Metrology Components?

The answer is 'yes' for almost every application. The advantages of granite include: No rust or corrosion, almost immune to warping, no compensating hump when nicked, longer wear life, smoother action, greater precision, virtually non-magnetic, low co-efficient of thermal expansion, and low maintenance cost.

Granite is a type of igneous rock quarried for its extreme strength, density, durability, and resistance to corrosion. But granite is also very versatile– it’s not just for squares and rectangles! In fact, Starrett Tru-Stone confidently works with granite components engineered in shapes, angles, and curves of all variations on a regular basis—with excellent outcomes.

Through our state of the art processing, cut surfaces can be exceptionally flat. These qualities make granite the ideal material to create custom-size and custom-design machine bases and metrology components. Granite is:

machineable
precisely flat when cut and finished
rust resistant
durable
long lasting
Granite components are also easy to clean. When creating custom designs, be sure to choose granite for its superior benefits.

STANDARDS / HIGH WEAR APPLICATIONS
The granite utilized by ZhongHui for our standard surface plate products has high quartz content, which provides greater resistance to wear and damage. Our Superior Black and Crystal Pink colors have low water absorption rates, minimizing the possibility of your precision gages rusting while setting on the plates. The colors of granite offered by ZhongHui result in less glare, which means less eyestrain for individuals using the plates. We have chosen our granite types while considering thermal expansion in an effort to keep this aspect minimal.

CUSTOM APPLICATIONS
When your application calls for a plate with custom shapes, threaded inserts, slots or other machining, you’ll want to select a material like Black Diabase. This natural material offers superior stiffness, excellent vibration dampening, and improved machinability.

Yes, if they are not too badly worn. Our factory setting and equipment allow the optimum conditions for proper plate calibration and rework if necessary. Generally, if a plate is within .001" of the required tolerance, it can be resurfaced on-site. If a plate is worn to the point where it is more than .001" out of tolerance, or if it is badly pitted or nicked, then it will need to be sent to the factory for grinding prior to relapping.

Great care should be exercised in selecting an on-site calibration and resurfacing technician. We urge you to use caution in selecting your calibration service. Ask for accreditation and verify the equipment that the technician will use has a National Inspection Institution traceable calibration. It takes many years to learn how to properly lap precision granite.

ZhongHui provides quick turn-around on calibrations performed in our factory. Send your plates in for calibration if possible. Your quality and reputation depend on the accuracy of your measurement instruments including surface plates!

Our black surface plates have a significantly higher density and are up to three times as stiff. Therefore, a plate made of the black does not need to be as thick as a granite plate of the same size to have equal or greater resistance to deflection. Reduced thickness means less weight and lower shipping costs.

Beware of others who use lower quality black granite in the same thickness. As stated above, properties of granite, like wood or metal, vary by material and color, and is not an accurate predictor of stiffness, hardness, or wear resistance. In fact, many types of black granite and diabase are very soft and not suitable for surface plate applications.

No. The specialized equipment and training necessary to rework these items requires that they be returned to the factory for calibration and rework.

Yes. Ceramic and granite have similar characteristics, and the methods used to calibrate and lap granite can be used with ceramic items as well. Ceramics are more difficult to lap than granite resulting in a higher cost.

Yes, provided that the inserts are recessed below the surface. If steel inserts are flush with, or above the surface plane, they must be spot-faced down before the plate can be lapped. If required, we can provide that service.

Yes. Steel inserts with the desired thread (English or metric) can be epoxy bonded into the plate at the desired locations. ZhongHui uses CNC machines to provide the tightest insert locations within +/- 0.005”. For less critical inserts, our locational tolerance for threaded inserts is ±.060". Other options include steel T-Bars and dovetail slots machined directly into the granite.

Inserts that are properly bonded using high strength epoxy and good workmanship will withstand a great deal of torsional and shear force. In a recent test, using 3/8"-16 threaded inserts, an independent testing laboratory measured the force required to pull an epoxy-bonded insert from a surface plate. Ten plates were tested. Out of these ten, in nine cases, the granite fractured first. The average load at the point of failure was 10,020 lbs. for gray granite and 12,310 lbs. for black. In the single case where an insert pulled free of the plate, the load at the point of failure was 12,990 lbs.! If a work piece forms a bridge across the insert and extreme torque is applied, it is possible to generate enough force to fracture the granite. Partially for this reason, ZhongHui gives guidelines for the maximum safe torque that can be applied the epoxy bonded inserts: https://www.zhhimg.com/standard-thread-inserts-product/

Yes, but only at our factory. At our plant, we can restore almost any plate to 'like-new' condition, usually for less than half the cost of replacing it. Damaged edges can be cosmetically patched, deep grooves, nicks, and pits can be ground out, and the attached supports can be replaced. In addition, we can modify your plate to increase its versatility by adding solid or threaded steel inserts and cutting slots or clamping lips, per your specifications.

Why Choose Granite?
Granite is a type of igneous rock formed in the Earth millions of years ago. The composition of igneous rock contained many minerals such as quartz that is extremely hard and wear-resistant. In addition to hardness and wear resistance granite has approximately half the coefficient of expansion as cast iron. As its volumetric weight is approximately one third that of cast iron, granite is easier to manoeuvre.

For machine bases and metrology components, black granite is the colour most used. Black granite has a higher percentage of quartz than other colours and is, therefore, the hardest wearing.

Granite is cost-effective, and cut surfaces can be exceptionally flat. Not only can it be hand lapped to achieve extremes of accuracy, but re-conditioning can be performed without moving the plate or table off-site. It is entirely a hand lapping operation and generally costs much less than re-conditioning a cast iron alternative.

These qualities make granite the ideal material to create custom-size and custom-design machine bases and metrology components such as the granite surface plate.

ZhongHui produces bespoke granite products that are created to support specific measurement requirements. These bespoke items vary from straight edges to tri squares. Due to the versatile nature of granite, the components can be produced to any size required; they are hard wearing and long-lasting.

Advantages of Granite Surface Plates
The importance of measuring on an even surface was established by British inventor Henry Maudsley in the 1800s. As a machine tool innovator, he determined that consistent production of parts required a solid surface for reliable measurements.

The industrial revolution created a demand for measuring surfaces, so engineering company Crown Windley created manufacturing standards. The standards for surface plates were first set by Crown in 1904 using metal. As the demand and cost for metal increased, alternative materials for the measuring surface were investigated.

In America, monument creator Wallace Herman established that black granite was an excellent surface plate material alternative to metal. As granite is non-magnetic and doesn’t rust, it soon became the preferred measuring surface.

A granite surface plate is an essential investment for laboratories and test facilities. A granite surface plate of 600 x 600 mm can be mounted on a support stand. The stands provide a working height of 34” (0.86m) with five adjustable points for levelling.

For reliable and consistent measurement results, a granite surface plate is crucial. As the surface is a smooth and stable plane, it enables instruments to be carefully manipulated.

The main advantages of granite surface plates are:

• Non-reflective
• Resistant to chemicals and corrosion
• Low coefficient of expansion compared with cart iron so less affected by temperature change
• Naturally rigid and hard-wearing
• The plane of the surface is unaffected if scratched
• Will not rust
• Non-magnetic
• Easy to clean and maintain
• Calibration and resurfacing can be done onsite
• Suitable for drilling for threaded support inserts
• High vibration damping

For many shops, inspection rooms and laboratories, precision granite surface plates are relied on as the basis for accurate measurement. Because every linear measurement depends on an accurate reference surface from which final dimensions are taken, surface plates provide the best reference plane for work inspection and layout prior to machining. They also are ideal bases for making height measurements and gaging surfaces. Further, a high degree of flatness, stability, overall quality and workmanship make them a good choice for mounting sophisticated mechanical, electronic and optical gaging systems. For any of these measurement processes, it is imperative to keep surface plates calibrated.

Repeat Measurements and Flatness
Both flatness and repeat measurements are critical to ensure a precision surface. Flatness can be considered as all points on the surface being contained within two parallel planes, the base plane and the roof plane. The measurement of distance between the planes is the overall flatness of the surface. This flatness measurement commonly carries a tolerance and may include a grade designation.

The flatness tolerances for three standard grades are defined in the federal specification as determined by the following formula:
Laboratory Grade AA = (40 + diagonal² / 25) x 0.000001 inch (unilateral)
Inspection Grade A = Laboratory Grade AA x 2
Tool Room Grade B = Laboratory Grade AA x 4

In addition to flatness, repeatability must be ensured. A repeat measurement is a measurement of local flatness areas. It is a measurement taken anywhere on the surface of a plate that will repeat within the stated tolerance. Controlling local area flatness to a tighter tolerance than overall flatness guarantees a gradual change in surface flatness profile, thereby minimizing local errors.

To ensure a surface plate meets both the flatness and repeat measurement specifications, manufacturers of granite surface plates should use Federal Specification GGG-P-463c as a basis for their specifications. This standard addresses repeat measurement accuracy, material properties of surface plate granites, surface finish, support point location, stiffness, acceptable methods of inspection and installation of threaded inserts.

Before a surface plate has worn beyond specification for overall flatness, it will show worn or wavy posts. Monthly inspection for repeat measurement errors using a repeat reading gage will identify wear spots. A repeat reading gage is a high-precision instrument that detects local error and can be displayed on a high magnification electronic amplifier.

Checking Plate Accuracy
By following a few simple guidelines, an investment in a granite surface plate should last for many years. Depending on plate usage, shop environment and required accuracy, frequency of checking the surface plate accuracy varies. A general rule of thumb is for a new plate to receive a full recalibration within one year of purchase. If the plate is used frequently, it is advisable to shorten this interval to six months.

Before a surface plate has worn beyond specification for overall flatness, it will show worn or wavy posts. Monthly inspection for repeat measurement errors using a repeat reading gage will identify wear spots. A repeat reading gage is a high-precision instrument that detects local error and can be displayed on a high magnification electronic amplifier.

An effective inspection program should include regular checks with an autocollimator, providing actual calibration of overall flatness traceable to National Institute of Standards and Technology (NIST). Comprehensive calibration by the manufacturer or an independent company is necessary from time to time.

Variations Between Calibrations
In some cases, there are variations between surface plate calibrations. Sometimes factors such as surface change resulting from wear, incorrect use of inspection equipment or use of noncalibrated equipment can account for these variations. The two most common factors, however, are temperature and support.

One of the most important variables is temperature. For instance, the surface might have been washed with a hot or cold solution prior to calibration and not allowed sufficient time to normalize. Other causes of temperature change include drafts of cold or hot air, direct sunlight, overhead lighting or other sources of radiant heat on the surface of the plate.

There also can be variations in the vertical temperature gradient between winter and summer. In some cases, the plate is not allowed sufficient time to normalize after shipment. It is a good idea to record the vertical gradient temperature at the time the calibration is performed.

Another common cause for calibration variation is a plate that is improperly supported. A surface plate should be supported at three points, ideally located 20% of the length in from the ends of the plate. Two supports should be located 20% of the width in from the long sides, and the remaining support should be centered.

Only three points can rest solidly on anything but a precision surface. Attempting to support the plate at more than three points will cause the plate to receive its support from various combinations of three points, which will not be the same three points on which it was supported during production. This will introduce errors as the plate deflects to conform to the new support arrangement. Consider using steel stands with support beams designed to line up with the proper support points. Stands for this purpose are generally available from the surface plate manufacturer.

If the plate is properly supported, precise leveling is only necessary if an application specifies it. Leveling is not necessary to maintain the accuracy of a properly supported plate.

It is important to keep the plate clean. Airborne abrasive dust is usually the greatest source of wear and tear on a plate, as it tends to embed in workpieces and the contact surfaces of gages. Cover plates to protect them from dust and damage. Wear life can be extended by covering the plate when not in use.

Extend Plate Life
Following a few guidelines will reduce wear on a granite surface plate and ultimately, extend its life.

First, it is important to keep the plate clean. Airborne abrasive dust is usually the greatest source of wear and tear on a plate, as it tends to embed in workpieces and the contact surfaces of gages.

It also is important to cover plates to protect it from dust and damage. Wear life can be extended by covering the plate when not in use.

Rotate the plate periodically so that a single area does not receive excessive use. Also, it is recommended to replace steel contact pads on gaging with carbide pads.

Avoid setting food or soft drinks on the plate. Many soft drinks contain either carbonic or phosphoric acid, which can dissolve the softer minerals and leave small pits in the surface.

Where to Relap
When a granite surface plate needs re-surfacing, consider whether to have this service performed on-site or at the calibration facility. It is always preferable to have the plate relapped at the factory or a dedicated facility. If, however, the plate is not too badly worn, generally within 0.001 inch of the required tolerance, it can be resurfaced on-site. If a plate is worn to the point where it is more than 0.001 inch out of tolerance, or if it is badly pitted or nicked, then it should be sent to the factory for grinding prior to relapping.

A calibration facility has the equipment and factory setting providing the optimum conditions for proper plate calibration and rework if necessary.

Great care should be exercised in selecting an on-site calibration and resurfacing technician. Ask for accreditation and verify the equipment that the technician will use has a NIST-traceable calibration. Experience also is an important factor, as it takes many years to learn how to correctly lap precision granite.

Critical measurements start with a precision granite surface plate as a baseline. By ensuring a reliable reference by using a properly calibrated surface plate, manufacturers have one of the essential tools for reliable measurements and better quality parts.

Checklist for Calibration Variations

1. The surface was washed with a hot or cold solution prior to calibration and was not allowed sufficient time to normalize.
2. The plate is improperly supported.
3. Temperature change.
4. Drafts.
5. Direct sunlight or other radiant heat on the surface of the plate. Be sure that overhead lighting is not heating the surface.
6. Variations in the vertical temperature gradient between winter and summer. If at all possible, know the vertical gradient temperature at the time the calibration is performed.
7. Plate not allowed sufficient time to normalize after shipment.
8. Improper use of inspection equipment or use of noncalibrated equipment.
9. Surface change resulting from wear.

Tech Tips
Because every linear measurement depends on an accurate reference surface from which final dimensions are taken, surface plates provide the best reference plane for work inspection and layout prior to machining.

Controlling local area flatness to a tighter tolerance than overall flatness guarantees a gradual change in surface flatness profile, thereby minimizing local errors.