KR100809803B1 - Manufacturing method of friction material - Google Patents

Abstract

An object of the present invention is to provide a method of manufacturing a friction member that realizes a reduction in time in the manufacturing process while maintaining the quality of the friction material and further suppressing introduction equipment and maintenance costs.

The above-mentioned means for solving the problem is to form a molding material, which is a friction material raw material, through a molding process of press-heating in a forming mold including an upper mold (1), a middle mold (2), and a lower mold (3). In the manufacturing method of the friction member 4, the mold temperature of the upper mold | type 1 and the lower mold | type 3 of the said molding process is 190-230 degreeC, and a pressure is 0.05-10 MPa.

Friction material

Description

Manufacturing method of friction material

1 is a block diagram showing an example of a manufacturing process of a general friction member.

2 is an enlarged cross-sectional view of a main part of an example of a manufacturing apparatus for implementing the present invention.

<Explanation of symbols for the main parts of the drawings>

1: Pictograph

2: Medium

3: bottom type

4: friction member

5: back plate

Japanese Patent Publication No. 2003-268352

Japanese Patent Publication No. 2003-145565

The present invention relates to a method for producing a friction member which is favorably used for disc pads, brake linings and the like of automobiles, heavy trucks, railway vehicles, various industrial machines, and the like.

The friction member is made of a product by attaching a background metal (back plate) to the friction material, such as a disk pad, or of a friction material, such as a brake lining.

edige mixer), 아이리히 믹서(Eirich mixer) 등의 혼합기를 이용하여 균일하게 혼합하는 [혼합공정], 혼합된 각 소재를 일정량 금형에 투입하고 프레스 기로 가압하여 예비성형품으로 하는 [예비성형공정], 예비성형품을 별도의 프레스 기로 가압·가열하는 [성형공정], 마찰부재 전체의 열 경화성 수지의 반응을 완결시키고 마찰성 수지의 안정화와 기계적 강도를 확보하기 위한 [열처리 공정], [도장공정], 마찰재 면의 연마와 홈의 형성과 사면의 형성을 행하는 [연마공정], 마찰재 표면을 가볍게 태워서 신품 시의 브레이크 효율을 확보하는 [스코칭 공정], [검사공정]을 거쳐서 제작된다. 또한, 디스크 패드의 경우는, 상기 성형공정 시에 미리 펀칭 가공되고, 탈지처리, 블라스트 처리, 화성처리, 프라이머 처리 등이 행하여진 백 플레이트와 마찰재가 접착 성형되는 것으로 된다. In general, the friction member is a mixer (L) to support the raw material of the friction material made of a fiber base, a filler, a binder, etc.

[Mixing process] to uniformly mix using a mixer such as an edige mixer, an Eirich mixer, etc. [Preforming process] in which each mixed material is put into a predetermined amount of mold and pressurized with a press machine to form a preform. [Forming process] pressurizing and heating the preform using a separate press machine, [Heat treatment process], [Painting process], and friction material to complete the reaction of the thermosetting resin of the friction member as a whole, and to stabilize the frictional resin and secure mechanical strength. It is produced through the "polishing process" for polishing the surface, the formation of the grooves, and the formation of the slope, and the "scoring process" and the "inspection process" for lightly burning the surface of the friction material to secure the brake efficiency at the time of new production. In the case of the disk pad, the back plate and the friction material, which are punched in advance during the forming step and subjected to degreasing treatment, blast treatment, chemical conversion treatment, primer treatment and the like, are adhesively molded.

In the above-mentioned [molding step], the conventional friction material is pressurized and heated for 5 to 10 minutes in a state of a pressure of 35 MPa and a mold temperature of 180 ° C., as described in Patent Document 1, for example. It is pressurized and heated for about 5 to 15 minutes in the state of the pressure of 30-50 MPa and mold temperature 130-180 degreeC.

And as described in patent document 2, since the thermosetting resin is contained as a binder in a friction material raw material, what is called gas degassing is removed about several times during pressurization and heating. These conditions are indispensable for maintaining the quality of the friction material. However, since high pressure is required (particularly in the case of using a mold having a plurality of cavities), the equipment becomes large, and the mold temperature is simply increased. If you try to shorten the time, the degassing of the generated gas will worsen, causing problems such as quality problems, such as swelling or cracking, in the friction material.How do you improve the molding process when considering the new cost down of the friction material? The question is whether to go.

In view of the above circumstances, it is an object of the present invention to provide a method of manufacturing a friction member which realizes a reduction in time of the manufacturing process while maintaining the quality of the friction material and suppressing introduction equipment and maintenance costs.

The structure of this invention which aims at solving the said subject is a manufacturing method of the friction member which shape | molds the molding material which becomes a friction material raw material through the shaping | molding process which press-heats in the shaping | molding die provided with an upper mold | type, a middle mold, and a lower mold | type. In the molding process, the upper and lower mold temperatures are 190 to 230 ° C., and the middle mold temperatures are lower than the curing temperature above the softening temperature of the resin contained in the molding material by the thermal conductivity of the upper and lower mold temperatures. And the pressure is set to 0.05 to 10 MPa.
In addition, a medium type can be made into the structure formed with the porous material, and the structure containing the material which has magnetic property. Furthermore, the mold temperature of the medium type can be adjusted to 190 to 230 ° C by high frequency heating during the molding step.

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In the present invention, the molding material is preferably a granulated material, and the molding material is preferably preheated. In addition, it is preferable to make this preheating by dielectric heating by a high frequency or a microwave.

The present invention pressurizes and heat-forms at a higher temperature and a smaller pressure than the conventional one, and adjusts the mold temperature of the medium-type in a suitable manner in consideration of the curing temperature of the resin in the molding material. Since it is possible to manufacture a friction member, it is not necessary to use a huge facility, for example, a large hydraulic type heat press device, as in the prior art, and a molding mold made of a soft material that breaks down with a conventional device ( Since the shape can be used, it is possible to obtain a special effect that it is possible to manufacture a friction member having good efficiency and low cost, and furthermore without bulging or cracking.

In addition, the effect peculiar to the present invention is explained in comparison with the conventional method. In the related art, when the molding temperature is too high, the curing reaction of the friction material is rapidly progressed, and a large amount of reactive gas is generated so that cracks are generated. If the molding pressure is too small and the molding pressure is too small, it takes too long to compress the friction material, so that the molding is pressurized and heated at a molding temperature of 180 ° C. or lower and a large molding pressure of 30 to 50 MPa. This is done. However, even when heated to a molding temperature of more than 180 ℃, if the molding pressure is small, cracks do not occur, and even if the molding pressure is small, heating to a molding temperature of more than 180 ℃, it is possible to compress the friction material raw material in a short time Turned out. As mentioned above, it is considered that cracking occurs because the molding temperature is high and a large amount of gas is suddenly generated. However, if the molding pressure is large, compression takes time when the molding pressure is small. It is assumed that is largely related.

The friction material raw material mixture undergoes compression deformation by being compressed. When the pressure is removed during the degassing treatment, the compression deformation is opened in the thickness direction, resulting in a spring back. The greater the pressure, the greater the compression strain and the greater the amount of spring back.

In other words, if the molding pressure is large, it is compressed to almost the same height as the product by the first press. Because of the high molding temperature, a large amount of reactive gas is generated rapidly inside the friction material, and the internal pressure of the friction material is high. When degassing in this state, a friction material springs back and a large amount of gas blows out from the side surface of a friction material. As a result, cracks occur.

In addition, the friction material raw material is in a state in which the resin melts and flows easily by being heated, and compression is possible even at a small pressure. However, if the molding temperature is low, it takes time until the resin is in a state where the resin is easily melted and flowed, and therefore it takes time to compress at a small pressure.

In contrast, since the present invention gradually pressurizes at a small pressure, the amount of spring back is small, and cracks are less likely to occur even when a large amount of gas is ejected, and the resin melts quickly because it is heated to a high temperature. The friction material is easily flowable, and the friction material can be compressed in a short time even at a small pressure. In addition, according to the present invention, the medium mold temperature is heated to a temperature higher than the softening temperature of the resin or lower than the curing temperature during the molding step, for example, at the start time. Since the resin on the side of the friction member in contact with the medium die does not harden, gas is easily released to the side. Since gas is easy to come out, it can shape | mold in shorter time and the friction member with a favorable appearance can be obtained. When the gas is released to some extent, the heating is performed at a high temperature of 190 to 230 ° C. on the way, so that an effect capable of quickly completing curing of the resin on the friction member side surface is obtained.

Next, the example of embodiment of this invention is described based on drawing. 1 is a block diagram showing an example of a manufacturing process of a general friction member, Figure 2 is an enlarged cross-sectional view of the main portion of an example of a manufacturing apparatus for implementing the present invention.

Figure 1 shows the flow of the manufacturing process of the general friction member described above. FIG. 2 is an apparatus used in the molding process in FIG. 1 and is an example of an apparatus for carrying out the present invention.

In FIG. 2, 1 is an upper mold | type, 2 is a middle mold which has a penetration hole up and down, and 3 is a lower mold inserted into the through-hole of this middle mold 2, and these upper molds (1), the middle mold (2), and the lower mold (3) This constitutes a heat press apparatus for carrying out the present invention. 4 is a friction member molded by this hot press apparatus, and 5 is a back plate of this friction member 4. In addition, although the example which manufactures the disk pad which attached the back plate 5 to the friction member 4 is shown in FIG. 2, the application of this invention also applies only to the friction member 4 which does not have a back plate like a brake lining. It becomes a target.

The upper mold | type 1 and the lower mold | type 3 mentioned above use the metal thing here. In addition, although the thing made from metals, such as alloy tool steels JIS G 4404: 2006 SKD 11, can be used for the medium 2, It is preferable to form the medium 2 by a porous material.

This is because when the porous material is used, the thermal conductivity of the medium type is lowered, the mold temperature of the medium type can be kept constant, and the product quality becomes more stable. As a porous material, it is also possible to use a porous ceramic, but since the production of the medium-size by this ceramic becomes extremely expensive, there is a problem that the introduction cost is too high. Therefore, considering the cost of introduction, resins are used to crush wood, plywood, and wood as a porous material. It is preferable to use cement, concrete, mortar, and the like obtained by hardening the abrasive powder of the friction material with a resin.

In addition, the medium 2 contains a structure containing fillers for adjusting thermal conductivity such as graphite and metal powder, a structure containing magnetic materials such as black iron oxide, iron powder, and stainless powder, and further, for adjusting these thermal conductivity. Some configurations include fillers and magnetic materials. In connection with this, by containing the filler for thermal conductivity adjustment, the temperature of the middle die 2 can be raised rapidly, and the hardening of the side surface of the friction member 4 can be completed quickly. Moreover, it is possible to raise the temperature of the middle mold 2 in a shorter time by including a material having magnetic properties.

The molding process which puts the molding material which becomes a friction material raw material mentioned later in the shaping | molding die provided with the upper mold | type 1, the middle mold | type 2, and the lower mold | type 3 of the said heat press apparatus, and pressurizes and heats it. When molding the friction member through the mold, the mold temperature of the upper mold 1 and the lower mold 3 is 190 to 230 ° C and the pressure is 0.05 to 10 MPa in the molding process. At this time, it is preferable that the mold temperature of the middle mold 2 is lower than the curing temperature above the melting point of the resin contained in the molding material by the thermal conductivity of the mold temperatures of the upper mold 1 and the lower mold 3. Although this temperature changes with resin contained in a molding material, when using a phenol resin as an example, it is preferable if it can maintain at about 80-130 degreeC temperature.

It is presumed that the temperature can be maintained at the above temperature because, in the case of the middle die 2 formed of the porous material, the thermal conductivity is low, so that the temperature is difficult to rise even after repeated pressing and heating. The temperature of the middle mold (2) is lower than the upper mold (1) and the lower mold (3), and the curing temperature is lower than the melting point (softening temperature) of the resin contained in the molding material as described above. As a result, the curing reaction of the side surface of the friction member 4 in contact with the middle die 2 is delayed, and gas is easily released from the side surface.

According to the present invention, it is possible to adjust the mold temperature of the heavy mold 2 to 190 to 230 ° C by high frequency heating during the molding step, for example, from the second half of the molding step or before the end of the molding step. The mold temperature of the middle die 2 is maintained at the above-mentioned temperature by the heat conduction of the mold temperature of the upper die 1 and the lower die 3 as described above at the start stage of the molding process, but the friction member 4 at the end of the molding process. It is because it is necessary to raise to hardening temperature at once in case of complete hardening reaction. In addition, although not shown about high frequency heating, the mold temperature of the middle mold | type 2 may be adjusted, for example using a high frequency induction heating coil.

Next, although the molding material which becomes a friction material raw material used for this invention may be a powdery thing, it is preferable that it is a granulated material. The use of such granules having a large particle size reduces the loss of pressure transfer (loss) due to friction between the particles. That is, it is possible to shape | mold at lower pressure than when using a powdery thing, and it is possible to pressurize and heat-mold in a short time.

Although the molding material does not need to preheat, what was preheated is normally used. In the present invention, the preliminary heating of the molding material may be performed by dielectric heating by high frequency or microwave which can be internally heated.

After the above forming process, the friction member 4 and the back plate 5 are transferred to a heat treatment step, and the heat treatment is a method of heat treatment in a high temperature atmosphere in a heat treatment furnace, and a method of being inserted into a high temperature hot plate to heat treatment. It is possible to carry out. The method of being attached to a hot plate is preferable because it can be processed in a short time.

Although the form example of this invention is as above, the Example of this invention is demonstrated with a comparative example below.

[Examples 1-17]

The friction member raw materials of the composition shown in following Table 1 were manufactured, respectively, under the molding conditions shown in Table 2, and the friction members of Example 1-17 were respectively manufactured, and the comparative examples 1 ~ under the molding conditions shown in Table 3 similarly Each friction member of Comparative Example 8 was prepared. Tables 2 and 3 also show the product appearance, abrasion resistance, and coefficient of friction of each friction member produced.

[evaluation]

Evaluation about the friction member of the said Example 1-Example 17, and the friction member of the comparative example 1-the comparative example 8 is shown in Table 2 and Table 3 similarly, respectively.

The present invention is superior to the conventional friction material by pressurizing and heat-molding at a lower pressure and a higher temperature than the conventional one, without pressing and heating at the same pressure as the conventional friction material manufacturing method and a temperature of 180 ° C. or lower. It is possible to produce a friction member having a good appearance and performance that is not inferior to a short time and at a low cost.

The present invention pressurizes and heat-forms at a higher temperature and a smaller pressure than the conventional one, and adjusts the mold temperature of the medium-type in a suitable manner in consideration of the curing temperature of the resin in the molding material. Since it is possible to manufacture the friction member, it is not necessary to use a huge facility, for example, a large hydraulic heat press apparatus, as in the prior art, and a molding mold made of a soft material that breaks down with a conventional apparatus. Since the shape can be used, it is possible to obtain a special effect that it is possible to manufacture a friction member having good efficiency and low cost, and furthermore without bulging or cracking.

Claims (20)

In the manufacturing method of the friction member which shape | molds the molding material which becomes a friction material raw material through the shaping | molding process which press-heats in the shaping | molding die provided with an upper mold | type, a middle mold, and a lower mold | type, The mold temperature of the upper mold and lower mold of the molding process is 190 to 230 ° C, By the heat conduction of the mold temperature of the upper mold and the lower mold, the medium mold temperature is lower than the curing temperature above the softening temperature of the resin contained in the molding material. Method for producing a friction member, characterized in that the pressure is 0.05 ~ 10MPa. The method of claim 1, The medium is a friction member manufacturing method formed of a porous material. The method of claim 1, The said medium type | mold contains the material which has a magnetic, The manufacturing method of the friction member which makes the medium-form mold temperature 190-230 degree | times by the high frequency heating before the latter half or the end of a shaping | molding process. The method of claim 2, The said medium type | mold contains the material which has a magnetic, The manufacturing method of the friction member which makes the medium-form mold temperature 190-230 degree | times by the high frequency heating before the latter half or the end of a shaping | molding process. The method according to any one of claims 1 to 4, The said molding material is a manufacturing method of the friction member which is a granulated material. The method according to any one of claims 1 to 4, The molding material is a method for producing a friction member that is preheated. The method of claim 5, The molding material is a method for producing a friction member that is preheated. The method of claim 6, The preliminary heating is a method of manufacturing a friction member, which is by high frequency or dielectric heating by microwaves. The method of claim 7, wherein The preliminary heating is a method of manufacturing a friction member, which is by high frequency or dielectric heating by microwaves. delete delete delete delete delete delete delete delete delete delete delete

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