DE1571616A1 - Process for the manufacture of graphite binder grinding wheels - Google Patents

Description

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4945 Naojiro Kumagai, Meguro-Ku, Tokyo-To / Japan

Process for the production of graphite blinding agents Grinding wheels

The invention relates to soles and a special one on a process for the production of Graphlt-Blndealttel-Sohlelfeoheiben fua Prttsielonesoleifen.

Bela Fräsiaioneeobleifen arise from the sole heat not only attacked (unhealthy) sole skin and fieetspannungen la calibrated workpiece, but the Eye warmth is also often the cause of serious Damage »for example grinding cracks. You sole heat arises from friction and the main part of the for that Grinding applied work or energy turns into frictional work or energy converted, i.e. to overcome the Friction as with glazed grains and the iu abrasive WerkstUok and the friction as well as the binding agent and the Chips consumed · Therefore, even when a large amount of a coolant is used, cooling is more locally heated Areas unserviceable and cause many deficiencies. the Grinding heat is therefore a great deal for pre-ef Problem. ,

Among the known grinding wheels there are glazed ones

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BATH

Grinding wheels that use ion for the binder, resin-like grinding wheels that use synthetic Harae, grinding wheels with metallic binders, metals such as copper, nickel or iron are used, and grinding wheels with other binders. In all of these grinding wheels, however, the coefficient of friction of the binding agent is high and the wearing of the binding agent, which influences the self-hardening of the abrasive grains, is advantageous in every pail at the same time enlarged.

Especially when using diamond wheels, the grinding heat and the irregular removal of the chips cause a «wear of the cutting edges of the diamond wafer due to chemical reactions, what causes the sole grinding process is severely disturbed. In addition, the grinding tools are used by the removed chips or removed so that they fall off. That’s a big part of the crowd, the “sole elves of various heat-treated steels, which give off fluids, make them unaöglloh.

When pr & giaionaso grinding, it is therefore important to keep the sole heat to reduce as much as possible, an aögliohat smooth Remove the chips, avoid the occurrence of damaged layers and residual stress, see the roughness of the treated surfaces iu decrease and the accuracy of the order of magnitude of the molluscs.

109808/0404

Ib / IbIb

To reduce the grinding heat, sum smooth removal of the Chips and to facilitate the self-sharpening of the grinding tools through suitable micro-sealing of the binding agent, a binding agent with a low stress coefficient is achieved, high lubricity, high thermal conductivity and high flexural strength are required.

The invention is therefore based on the task of "announcing these properties in material old in order to produce grinding wheels for precision soles, esp. a process iur production of grinding wheels with these properties voriuschiageη.

The invention is directed in particular to the lamination of glazed grinding wheels by binding various grinding bodies instead of a binding agent which is approximately in the same state as a hard graphite pencil and has properties such as grip, slip, point stability and suitable micro-quality.

the invention is sur in the method of manufacturing clay graphite Bindefflittel-Sohleifeoheiben an Au · 30 - 70 1 "Kaolin 70 - 30 £ Montmorillonlt and 40 - 60 Jt finely powdered ·« graphite existing binder in the state of a hard Graphitetifte · with selected abrasive grains intimately ▼ · «nieent. 3 - 10 pounds of water are added to the mixture. The resulting M ⁿ t "is rial

BAD OR1G ^J NAL 109808/0404

IU press-molded of a grinding wheel nit selective Grude and then in a Graphitgefäfi under a neutral atmosphere at temperatures reduslerenden or "wipe and heated 850 to 95O ⁰ sintered G, where ei" sintered * old Mikroporcn arises equipped grinding wheel. In addition, the micropores are impregnated with a lubricant, such as stearic acid.

A binder with the texture of a hard graphite pencil possesses non-independent τοη the kind of the reused Abrasives - only a flexural strength that is swei - or Is four times as large as that of the used binding agent » but also has many other properties mentioned above.

If the micropores of this binder are impregnated with a lubricant such as stearic acid, for example, the eonet necessary use of a coolant becomes superfluous. In addition, a grinding wheel made with this binding agent can be used to grind trooken »whereby only sole elevation temperatures below 270 ⁰ O are locally generated, consequently the sole process can be continued without damaging the sole grinded surface, without causing high stresses or grinding cracks. "You get a regular and clear tone corresponding to the original color and the original shine of the workpiece material and fresh shavings that are smoothly removed, whereby the rear edges of the sole separator are sharpened by means of a suitable abrasion of the grinding wheel.

According to the invention, they are similar to a hard graphite pencil Binder the compositions given by way of example in Table 1 and those given in Table 2 · « physical properties. SIs are made by sintering «ad

109808/0404

Impregnating their micropores with an agent such as stearic acid made so that strength and lubricity are increased.

Degree 5H 7H 9H Amorphous graphite
Kriatallineβ graphite
binder 19th
29
52 17th
27
56 15th
25th
60 Bindemi 11 e 1- cohesion 45
45
10 55
40
5 kaolin
Montraorillonite A
Montmorillonite B .leche Si genachai 60
37
3 5H 7H Degree ) * 0.223
2.35
16.2
7.4I
785 0.225
2.40
15-6
7.13
862 9H Coefficient of friction (J.1.3.
Specific weight
Waeeerabeorption (jt)
31 ear ine äureiiapr agnation (36)
Flexural strength (kg / cm ² ) 0.228
2.43
14.8
6.82
948

• Defined by TFaDan Industrial Trial Standard β "

BATH

To further clarify the invention, the following AusfUhrungsbelspiele given to which the invention, however not impressed let.

The binding agent corresponds to the combinations given in Table 1 are selected in accordance with the indicated degrees of the sole disc and are intimate with abrasive grains old a grain ratio τοη 15 to 48 Jt avoided. AnsohlieSend will be 3 to with each resulting mixture 5 per cent of water mixed uniformly. Then a hatall mold for a selected grinding wheel is filled with the resulting mixture, which is shaped under Brück * until it has the preselected density.

Each pressed grinding wheel with the determined by the shape öröße is removed from the mold and dried at a tem perature of ⁰ SO C. The dried, pressed soleplates are then placed in appropriate graphite casings and placed under a neutral or reducing atmosphere. atmosphere at a temperature '
to sinter the binders.

atmosphere heated at a temperature τοη 850 to 95O ⁰ C,

The sintered grinding wheels must be cooled to natural catfish. They are then immersed after Torerwärmung to 100 ⁰ C, in geechmolsen · stearic acid, .damit appropriate amounts of stearic acid in the Mlkroporen danaoh the finished grinding wheels are absorbed.

If a diamond grinding wheel is used then it will a 2 to 5 mm thick layer of diamond abrasive grains to a substrate in the form of a disk of the binder according to the invention and a suitable amount of silicon carbide grains contains, to a disc of a light

BATH ORIGINAL

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Alloy or bonded from synthetic resin, after which the grinding wheel is ready.

No more about the usefulness of the subject matter of the invention To emphasize, the single values for a grinding wheel according to the invention are given below.

The grinding process was carried out with the following material and executed under the following conditions:

Grinding machine old horizontal surface, manufactured by Okaaoto Machine Tool Mfg.Co., Ltd jnpan *

Size 20 $ in diameter, 19.5 in Möfce, 51.5 M in diameter.

Detail. / 80 SÄ Earnerf 25 1 » Density of the material 2.17- Workpiece! Mill steel (Japan Industrial StaBdarda Reward SKS2) * t Hart · Bookwell o64-

(* Zueaauaenaetsung (^) des Werkaeugetahla SK32: 1.00 - 1.10 Ci 0.35 (* ax.) Si? 0.80 (a & x) Mn; 0.030 (aax.) Ps 0.030 (eax.) S; 0.50-1.00 Orj 1.00-1.50 W. )

The speed of the grinding axis is 1,750 m / mLn Tlaohge ^ ohwlndlgkelt: 10 «/ * iQ

▲ wrote pro.Wagen 10 «iorone

Sole type »Trooken BAD ORlGiNAL

109808 / 0A04

The following results are obtained: Grinding supplies:

Number of ways Amount of
honed
Work pieces Amount of
Abrasion of the
Grinding -
disc Sole
never received O - 100
100-200
200-300
300-400 675
640
646
648 6.28
6.28
6.28
6.28 107
102
103
103

Surface roughness after grinding, whitened by Hadelinet muten t:

Without cross advance stroke. Without spark generation

Without cross feed

ddt Great dunking erseugung

Hit cross roreohub

With Tunkenerceugungf 1 way

With cross feed

With full sparks

Roughness! 1.2 «icrone Roughness «0.95 aicrone Roughness: 0.8 aicrona Roughness! 0.75 micreme

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BATH ORIGINAL

Measurements of the temperatures due to the grinding heat: (old constantan iron thermocouples)

Distance to BHK temperature surface (at the) («V) ⁰ C o.Ol 11.5 250 0.02 10.0. bit by bit o.03 7.5 less 0.07 6.5 0.09 6.0 0.12 5.0 0-14 5.0 0.16 4.0 0.20 3.0 0.22 2.5

The results show that the inventions made Grinding wheels are very suitable.

BATH

109808/0404

Claims (1)

4945 claims 1. Process for the production of clay graphite binders! Ttel grinding wheels sum precision grinding, thereby geke η η ζ eio h η β t that a binder of 30-70 kaolint 70-30 pounds montmorillanite and 40-60 percent by weight of finely powdered graphite with the Constitution of a hard graphite pencil with selected sole grains is intimately mixed, that 3-10 Jt water is added to the mixture and the mixture is then pressed into a grinding wheel of the desired size, and that after the grinding and sintering of the pressed wheel in a graphite vessel an inert atmosphere at a temperature between 850 and 95O ⁰ C, whereby a sintered disk is disfigured with micropores, the micropsrene being impregnated with a lubricant. 2 · Method according to Anepruoh I _9, characterized in that the lubricant is stearic acid. 109808/0404