JP6507658B2 - Method of manufacturing friction material for sliding part and friction material therefor - Google Patents

Description

  The present invention relates to a method of manufacturing a friction material of a sliding component integrally joined to a sliding component such as a synchro ring, and a friction material therefor.

  A friction material is joined to the synchro ring as the synchronization device of the transmission for a vehicle in order to increase the coefficient of friction with the other gear cone.

  Conventionally, as a friction material, it is formed of a sintered metal or the like, but it is inferior in wear resistance, so carbon friction material which is excellent in wear resistance and heat resistance and does not decrease in friction coefficient even when used for a long time is used It has become

  In this carbon friction material, artificial graphite as a solid lubricant, a reinforcing material such as wollastonite, a carbon fiber, and copper alloy particles for enhancing thermal conductivity are mixed together with a phenol resin, and heated and heated. It is molded by pressing.

  The friction material is required to have a contradictory performance that a high dynamic friction coefficient is required in order to obtain synchronization by contacting with the other gear cone and a low static friction coefficient is required when separating from the other gear cone.

  For this purpose, (a) it is necessary to cut the oil film so that there is no oil at the interface when contacting with the other gear cone for high dynamic friction coefficient, and (b) the contact area with the other gear cone for low static friction coefficient It is effective to make

  In order to obtain both the surfaces (a) and (b), it is effective to form dimples on the surface.

JP, 2011-021597, A Patent Document 1: Japanese Patent Application Publication No. 2003-045262 WO 2004/109138 JP 2005-113130 A

  Conventionally, there are methods such as laser irradiation and shot peening for forming dimples, but there is a problem that it can not be used for carbon friction materials.

  Therefore, an object of the present invention is to solve the above-mentioned problems, and to provide a method of manufacturing a friction material of a sliding component capable of forming dimples on the surface of a carbon friction material and a friction material therefor.

  In order to achieve the above object, according to the present invention, the raw material of the friction material is mixed with Millefeil carbon, which is filled into a mold and heated and pressed to form a friction material, and the surface of the friction material is cut. It is a manufacturing method of the friction material of the sliding part characterized by forming a dimple with the falling off mark of Millefeille carbon.

  Raw material of friction material consists of reinforcing material, carbon fiber, copper alloy particles and thermosetting resin, and this material is milled carbon of 5 to 20 μm in thickness, 3 to 10 pieces, 50 to 500 μm in particle diameter. It is preferable to mix and shape a friction material.

  Wollastonite is mixed with a phenol resin as the reinforcing material, the phenol resin forms a semi-cured raw material granulated powder, the carbon fiber is mixed with the phenolic resin, and the phenolic resin is semi-cured raw material granulated powder The raw material granulated powder is mixed with copper alloy particles, phenol resin and Mille-foil carbon, and then the whole material granulated powder with a particle size of 0.5 to 1.0 mm is formed, and this is used as a mold It is preferable to heat and press to fill the friction material, and to finish the surface of the friction material by cutting to form dimples on the surface.

  It is preferable that the dimples be formed by leaving the peel of the outer layer of milletite carbon dropped off by the cutting and finishing process on the surface of the friction material, and forming a crack in the peel of the dimple remaining on the surface.

  Further, the present invention is a friction material of a sliding component manufactured by the method of manufacturing a friction material of the above sliding component and characterized in that the area ratio of all the dimples is 20 to 25%.

  The present invention has the excellent effect of being able to form dimples by falling-off traces of Millefeil carbon by molding the friction material using Millefeil carbon as the raw material of the carbon friction material and cutting the surface of this friction material. Do.

It is the schematic which shows one Embodiment of the manufacturing method of the friction material of the sliding component of this invention. It is process drawing explaining the manufacturing method of the friction material of the sliding component of this invention. It is a figure which shows the microscope picture of the surface of the friction material obtained by this invention. It is a figure which shows the microscope picture of the surface of the conventional friction material. In this invention, it is a figure which shows the microscope picture of the surface of the friction material finished. It is a figure which shows the microscope picture of the surface of the friction material which finished the conventional friction material. In this invention, it is the figure which measured the relationship between the displacement at the time of destroying Millefeued carbon, and a test force. It is the figure which measured the relationship between the displacement at the time of destroying artificial graphite, and a test force. In this invention, it is a figure which shows the fracture strength of a mille-feuille carbon and artificial graphite. In this invention, it is a figure which shows the result of a wear test when using a mill fly carbon and artificial graphite for a friction material.

  Hereinafter, a preferred embodiment of the present invention will be described in detail based on the attached drawings.

  FIG. 1 shows an embodiment of a method of manufacturing a friction material for a sliding component according to the present invention.

First, a reinforcing material such as wollastonite (CaSiO ₃ ) and a phenolic resin powder as a thermosetting resin are mixed, and the phenolic resin is semi-cured to form raw material granulated powder 10 having a particle diameter of 125 μm to 250 μm. Granulate.

  The raw material granulated powder 10 consisting of wollastonite is added with 15 mass to 40 mass of phenol resin per 100 mass of wollastonite, which is heated at a temperature of 80 ° C. to 120 ° C. for 0.5 to 5 hours to make the phenol resin It is in a semi-cured state and granulated to a particle size of 50 μm to 500 μm.

  Similarly, carbon fiber (wire diameter 7 to 15 μm, length 80 to 150 μm) and phenolic resin powder are mixed, and the phenolic resin is semi-cured to granulate the raw material granulated powder 11 having a particle size of 50 to 500 μm. Form.

  The raw material granulated powder 11 made of this carbon fiber is formed by adding 15 mass to 40 mass of phenol resin to 100 mass of carbon fiber, and heating this at a temperature of 80 ° C. to 120 ° C. for 0.5 to 5 hours Is semi-hardened, and granulated to a particle size of 50 μm to 500 μm.

  Next, the raw material granulated powders 10 and 11 are charged into a mixer 21 and copper alloy particles 12 with a particle diameter of 50 μm ± 20 μm, such as brass powder, are added and mixed to form a premix 13.

  The content of the premix 13 is 8 mass to 20 mass of the raw material granulated powder 10 made of wollastonite, 8 mass to 20 mass of the raw material granulated powder 11 made of carbon fiber, and 5 mass to 15 mass of the copper alloy particles 12.

  After adding 10 mass-25 mass of phenol resin 14 to 100 mass of this pre-mix to make resin addition mixture 15, 45 mass-55 mass of Millefeued carbon 16 as a solid lubricant is added to 100 mass with respect to resin addition mixture 15 The material mixture 17 is used.

  Mille-feuille carbon 16 is calcined coke manufactured by Superior Graphite Co., and is obtained by heating petroleum-based straight heavy oil, coal tar pitch, etc. in a fluidized bed at a temperature of 250 to 450 ° C. A light fraction, which is a component of tar pitch, is evaporated to form mesophase flaky peels layered to form granules, with a skin thickness of 5 to 20 μm and 3 to 10 pieces. And consist of mesophase spheres with a particle size of 50 to 500 μm.

  Heat is applied to the whole material mixture 17 to which the mille-phile carbon 16 is added to make the phenol resin 14 into a semi-hardened state, and this is made into a whole material granulated powder 18 of 0.5 to 1.0 mm.

  The friction material 20 is formed by filling the granulated whole material granulated powder 18 in the forming dies 22A and 22A and heating and pressing.

  As the molded friction material 20 is molded using all-material granulated powder 18 with a constant particle diameter in the range of 0.5 to 1.0 mm, all-material granulated powder 18 is heated, Even when pressurized, the space of all the material granulated powder 18 is held, and pores are formed inside and the pores inside are connected to each other. As a result, the lubricating oil flowing into the pores becomes movable, and the heat generated by the friction can be dissipated by the lubricating oil.

  The friction material 20 may be attached to the sliding part after molding or may be joined to the sliding part together with the molding.

In FIG. 1, the adhesive 23 is previously applied to the ring rough material 19 of the synchro ring and dried, and this is set in the forming die 22A, and the whole material granulated powder 18 is placed between the ring rough material 19 and the forming die 22. Is filled, and then heated and pressurized (temperature 180 ° C. to 200 ° C., pressure 200 to 600 kg / cm ² , 0.5 to 1 hour) to bond the friction material 20 and the ring rough material 19 together.

  After joining, the surface of the friction material 20 is cut and finished so as to have a predetermined thickness (0.7 mm) to form the synchro ring 30.

  The friction material 20 is cut and finished, so that most of the mille-feuille carbon 16 on the surface of the friction material 20 falls off leaving the peel 16s of the outer layer of the mille-phile carbon 16, and the dimple 24 is formed by the peel 16s of the outer layer. It is formed. In addition, the outer layer skin 16s is in a cracked state due to crushing and falling off of the mille-feuille carbon 16.

  As described above, by forming the dimples 24 on the surface of the friction material 20, the contact area with the gear cone can be reduced, and it is possible to store lubricating oil in the dimples 24, and the static friction coefficient can be reduced.

  Further, when heat is generated by the contact friction with the gear cone, the lubricating oil can flow through the cracks of the dimples 24 and the pores formed in the friction material 20 to dissipate heat.

  Also, even if the friction surface of the friction material 20 is worn away by aging, Millefeil carbon 16 is mixed in the friction material 20, so if it is exposed on the surface, it collapses and falls off due to friction sliding with the gear cone. Thus, since a new dimple is formed, it is possible to maintain the dimple 24 formed at all times.

  FIG. 2 shows a process diagram for manufacturing the synchro ring.

  First, a rough material is formed in a ring shape by forging, and is further processed to have a predetermined size.

  Next, a carburized and hardened material is used as an iron base material (S1), and the surface to be joined with the friction material is subjected to shot blasting to roughen the surface (S2).

  Carbon composite (CC) film formation which directly molding the friction material is performed on the roughened iron base material (S3), and the surface of the friction material thus formed is finished (S4) and inspected (S5) It is a product of synchro ring.

  In the carbon composite film formation (S3), an adhesive is applied and dried (S3-1) on the roughened surface of the iron substrate, and this is set in a forming die (S3-2), and the inside of the forming die is formed. 1, in the mixing and granulation (S3-4) step described in FIG. 1, filling the raw material which is all the material granulated powder 18 separately manufactured (S3-3), and heat and pressure forming (S3-5) Then, the friction material joined with the adhesive is formed on the roughened surface, and then the mold is released from the mold (S3-6) to complete the carbon composite film formation (S3).

  FIG. 3 is a photograph of the inside of the friction material obtained in the present invention taken with a laser microscope, and it can be seen that a large number of pores are formed around the mille-feuille carbon.

  Fig. 4 is a photograph obtained by kneading wollastonite, carbon fiber, and copper alloy particles with a phenol resin using conventional artificial graphite as a friction material, and the inside of the friction material is photographed with a laser microscope, and pores are completely formed. It is understood that it is not done.

  FIG. 5 is a photograph of the surface of the friction material formed by the finishing process manufactured in FIG. 2 taken with a laser microscope.

  According to FIG. 5, it can be seen that the mille-feure carbon exposed on the surface of the friction material by the cutting and finishing process is dropped off and the dimple as the drop-off mark of the mille-feure carbon is formed on the surface.

  It was confirmed that the dimples were formed on the surface of the outer layer of the millet carbon by about 1 to 2 sheets of the outer layer of the millet carbon. The diameter of the dimples is approximately equal to the particle diameter of the mille-feuille carbon, and the area ratio of all the dimples is 20 to 25%. Also, in the dimples formed by the skin of the outer layer of the Milleuille carbon, cracks were observed on the surface when the skin of the outer layer fell off.

  By forming dimples with a cracked surface on the surface of the friction material in this way, the friction material can reduce the contact area with the other gear cone and can hold the lubricating oil in the dimples, so the coefficient of static friction is It can be made smaller. In addition, when frictional heat is generated due to dynamic friction with the other gear cone, the lubricating oil can receive the frictional heat, move through the dimples and pores, and dissipate heat.

  FIG. 6 is a photograph of the surface on which the friction material is cut and processed using the conventional artificial graphite described in FIG.

  In artificial graphite, no chipping marks were observed on the surface even after cutting and processing, and it was in a state of clogging.

  FIG. 7 is a view measuring the relationship between the displacement and the test force at the time of breaking Mille-feuille carbon, and FIG. 8 is a view measuring the relationship between the displacement and the test force at the time of breaking artificial graphite The number of samples was five.

  As shown by black circles in FIG. 7, Millefeille Carbon has a characteristic that displacement is small even if the test force is increased, and if it exceeds a certain test force, the outer layer peels off from the peel of the outer layer and the thin peel disappears to greatly displace it .

  Therefore, the surface of the molded friction material is cut and finished, whereby the skin of the outer layer of the mille-feuille carbon can be broken and the dimple can be easily formed.

  In contrast, as indicated by the dotted area R, artificial graphite also increases displacement as the test force increases. It can be seen that artificial graphite has the property of being resilient without breaking and sticky, and has high breaking strength.

  FIG. 9 shows the measurement of the fracture strength of mille-feuille carbon and artificial graphite. The fracture strength of the five sample averages was 24.8 MPa for mille-fee carbon and 31.0 MPa for artificial graphite.

  FIG. 10 shows the results of a long-term abrasion test when using Milleuille carbon and artificial graphite as a friction material.

  According to FIG. 10, it can be understood that the decrease in the wear coefficient for a long time is smaller than that of the friction material using artificial graphite, by using mille-feel carbon as the friction material.

  As described above, according to the present invention, dimples can be formed on the surface of the friction material by mixing mill-fille carbon with the raw material of the friction material, heating and pressure-forming the friction material, and then performing cutting and finishing.

10 raw material granulated powder 16 mill fee carbon 18 all material granulated powder 20 friction material 22A, 22B mold 24 dimple

Claims (4)

A method of manufacturing a friction material of a sliding part , which comprises mixing mill-fille carbon into a raw material of the friction material, filling it in a mold and heating and pressing it to form a friction material ,
The mille-feuille carbon is formed by layering flaky peels of calcined coke into layers,
The manufacturing method includes cutting off the surface of the friction material to leave most of the mille-fee carbon on the surface of the friction material, leaving the skin of the outer layer and forming dimples by the skin of the outer layer. A method of manufacturing a friction material of a sliding part characterized by   Raw material of friction material consists of reinforcing material, carbon fiber, copper alloy particles and thermosetting resin, and this material is milled carbon of 5 to 20 μm in thickness, 3 to 10 pieces, 50 to 500 μm in particle diameter. The method for producing a friction material of a sliding part according to claim 1, wherein the friction material is formed by mixing. Wollastonite is mixed with a phenol resin as the reinforcing material, the phenol resin forms a semi-cured raw material granulated powder, the carbon fiber is mixed with the phenolic resin, and the phenolic resin is semi-cured raw material granulated powder The raw material granulated powder is mixed with copper alloy particles, phenol resin and Mille-foil carbon, and then the whole material granulated powder with a particle size of 0.5 to 1.0 mm is formed, and this is used as a mold The friction material of the sliding part according to claim 1 or 2, wherein heat and pressure are applied to form the friction material, and the surface of the friction material is cut and finished to form dimples on the surface. Method. The method for manufacturing a friction material of a sliding part according to any one of claims 1 to 3 , wherein a crack is formed in the skin of the outer layer of mille-feure carbon left on the surface of the friction material.