JP4548149B2 - Sliding member for clutch and manufacturing method thereof - Google Patents

Description

  The present invention relates to a covering member that can be used as a sliding member for a clutch and a manufacturing method thereof. The present invention also relates to a sliding member used for a clutch of an automobile or the like and a manufacturing method thereof.

  In order to impart wear resistance and the like, a covering member in which a carbon-based or ceramic-based hard film is formed on the surface of a metal tool or machine part is used in a wide range of fields. For example, Patent Document 1 discloses a clutch plate in which a surface of an iron base material is shot blasted and a diamond-like carbon thin film is provided on the surface. Since the plate surface is ground and cleaned by shot blasting, the adhesion between the plate surface and the diamond-like carbon thin film is improved.

However, depending on the application and use conditions of the covering member, it is required to further improve the adhesion.
JP 2004-116763 A

In view of the above-mentioned problems, the present inventors provide a sliding member for a clutch having high adhesion between a base material and a hard film and having excellent durability, and a method for producing the sliding member for a clutch. Objective.

The clutch sliding member of the present invention is a clutch sliding member that transmits torque by friction, and has a metal base having irregularities formed by projecting a ceramic-based projection material on the surface, and the irregularities. at least a portion is integrally formed possess a hard film to slide a sliding surface, a Ru 2~6μmRz der surface roughness ten-point average roughness of the sliding surface along the It is characterized by that.

The clutch sliding member manufacturing method of the present invention is a method for manufacturing a clutch sliding member that transmits torque by friction, and projects a ceramic-based projection material on the surface of a metal substrate to produce irregularities. a rough surface formation step of forming a hard film forming step of forming a hard film at least partially slide a sliding surface along the surface of the unevenness, Ri Tona, the surface of the sliding surface the roughness ten-point average roughness, characterized in 2~6μmRz and to Rukoto.

In the clutch sliding member and the clutch sliding member manufacturing method of the present invention, the ceramic projection material is projected onto the surface of the substrate to form irregularities on the surface. The unevenness formed by the projection of a ceramic-based projection material, particularly an alumina-based projection material containing alumina, can enhance the adhesion with a hard film such as a carbon-based hard film due to its characteristic shape (described later). . In particular, by improving the adhesion between the base material and the hard film, the wear resistance of the sliding member for a clutch is improved.

  According to the clutch sliding member and the clutch sliding member manufacturing method of the present invention, the adhesion of the hard film is improved due to the characteristic shape (described later) of the unevenness formed on the surface of the base material, and the wear Since the decrease in the surface roughness of the sliding surface due to is suppressed, the wear resistance and sliding characteristics can be maintained over a long period of time, and the durability is excellent.

[Coating material]
The covering member mainly comprises a metallic substrate having an uneven surface, a hard carbonaceous film which is integrally formed on its uneven, the.

  The base material is not particularly limited as long as it is made of metal, and iron-based metals such as carbon steel and alloy steel, aluminum-based metals such as pure aluminum and aluminum alloys, and the like can be used. Further, the shape of the substrate is not particularly limited, and the surface on which the carbon hard film is coated may be a flat surface or a curved surface.

  A base material has the unevenness | corrugation formed by projecting the ceramic type | mold projection material on the surface. That is, the unevenness formed on the surface of the substrate is a fine unevenness formed by so-called shot blasting. Below, the shape of the unevenness | corrugation formed using the alumina type projection material containing an alumina especially suitable also among ceramics projection materials is demonstrated compared with the case where a glass bead is used.

  FIG. 7 is a diagram schematically showing a cross section of a base material subjected to shot blasting. When an alumina-based projection material is used (upper left diagram), the formed irregularities are denser than when a glass bead is used as the projection material (lower left diagram). Specifically, the distance between the two convex portions adjacent to each other (the distance from the tip of the convex portion to the tip of the adjacent convex portion when the base material is viewed in plan view; indicated by D in FIG. 4) is 40 μm or less. The thickness is preferably 3 to 30 μm. Moreover, the unevenness | corrugation formed when an alumina type projection material is used is formed in arbitrary height. Such a difference in the shape of the unevenness is due to a difference in the shape of the projection material. Glass beads are a spherical powder with a smooth surface, but ceramic-based projection materials such as alumina usually have a plurality of sharp edges on the surface. The surface of the base material is ground by this ridge angle, and irregularities having a characteristic shape are formed on the surface. And the active surface from which the contaminated film, the oxide film, etc. were removed is exposed in a wide area on the surface of the substrate ground by the projection of the alumina-based projection material.

  When the active surface is exposed in a large area on the surface of the base material, the base material and the carbon-based hard film formed on the unevenness of the surface of the base material exhibit better adhesion than before. Moreover, it is preferable that the surface of a base material is 2-6 micrometers Rz by 10-point average roughness (Rz), More preferably, it is 2.9-3.5 micrometers Rz. The covering member whose surface roughness is within the above range further improves the adhesion between the substrate and the carbon-based hard film.

  The carbon-based hard film is preferably an amorphous carbon film, a metal-containing carbon film, or a metal-containing carbonized film. The amorphous carbon film (Diamond Like Carbon: DLC film) may be an amorphous carbon (DLC-Si) film containing silicon. As the metal-containing carbon film, a film obtained by adding titanium (Ti), chromium (Cr), or tungsten (W) to the DLC film can be used. As the metal-containing carbide film, a titanium carbide (TiC) film, a tungsten carbide (WC) film, a laminated film of a tungsten carbide film and a carbon film (WC / C), or the like can be used.

[Method for producing coated member]
The above-described method for manufacturing a covering member mainly includes a rough surface forming step and a hard film forming step.

  The rough surface forming step is a step of forming irregularities by projecting a ceramic-based projection material onto the surface of a metal substrate. That is, the rough surface forming step in the present invention corresponds to so-called shot blasting. In particular, by performing shot blasting with an alumina-based projection material, irregularities having the shape described in detail in the column “Coating member” are formed on the surface of the substrate.

Examples of ceramic-based projection materials include Si ₃ N ₄ , SiO ₂ , SiC, and alumina such as brown alumina, white alumina, light red alumina, pulverized alumina, alumina zirconia, and high-purity alumina as defined in JIS R6111 Ceramics conventionally used as a shot blasting projection material can be used as the projection material. In particular, it is desirable to use an alumina-based projection material in which the above-mentioned alumina is used singly or in combination, and it is more desirable that the projection material contains brown alumina. Further, when the particle size of the ceramic-based projection material is 50 to 90 μm, it is suitable for forming the characteristic unevenness of the surface of the substrate as described above.

  At this time, the ceramic-based projection material is preferably projected onto the surface of the substrate at a pressure of 0.15 to 0.7 MPa, more preferably 0.25 to 0.35 MPa. By setting the projection pressure within the above range, the surface roughness of the substrate can be set to an optimum value. In addition, the relationship between the surface roughness of a base material and the projection pressure of the projection material at the time of using an alumina type projection material is shown in FIG. If the projection pressure is 0.15 to 0.7 MPa, a surface roughness of 2 to 6 μm Rz can be obtained. Moreover, if the projection pressure is 0.25 to 0.35 MPa, a surface roughness of 2.9 to 3.5 μm Rz is obtained.

  The hard film forming step is a step of forming a carbon-based hard film on the uneven surface formed in the rough surface forming step. In the unevenness formed in the rough surface forming step, the surface area of the active surface is increased due to the uneven shape as described above. Therefore, the adhesion between the base material and the carbon-based hard film is greatly improved as compared with the conventional case.

  As a method for forming the carbon-based hard film, the conventional CVD method (chemical vapor deposition method) or PVD method (physical vapor deposition method) may be used. In addition, when it is desired to reflect the surface roughness of the base material formed in the rough surface forming step on the surface roughness of the coating member after film formation, film formation by DC plasma CVD is suitable. In the direct current plasma CVD method, a glow discharge is generated by applying electric power between two electrodes having a potential difference to which a direct current power source is applied, and the process gas introduced between the electrodes is converted into a plasma using the glow discharge, This is a method of forming a deposited film on an electrode (base material) on the negative potential side. According to the DC plasma CVD method, the film is formed along the irregular surface shape formed in the rough surface forming process, so the surface roughness obtained in the rough surface forming process is maintained even after film formation. The surface roughness of the base material is well reflected in the covering member.

[Sliding member for clutch]
The clutch sliding member of the present invention is a clutch sliding member that transmits torque by friction. That is, the sliding surface of the clutch sliding member is in frictional engagement with the mating member, and relatively transmits power by the frictional force. The clutch sliding member may be, for example, a clutch member used in any one of a wet clutch, an electromagnetic clutch, a starting clutch, a lock-up clutch, a wet brake, and the like used in a vehicle automatic transmission and a driving force transmission device. There is no particular limitation. Further, it may be a multi-plate clutch composed of a plurality of clutch sliding members, or a single-plate clutch. Specifically, clutch plates 12a, 12b, 14a, and 14b of the electronically controlled coupling 10 for a four-wheel drive vehicle shown as an example in FIG.

  The clutch sliding member mainly has a metal base material having irregularities on the surface and a hard film formed on the irregularities.

  The base material is not particularly limited as long as it is made of metal, and may be made of a metal that is generally used as a sliding member for a clutch. However, an iron-based metal, specifically, carbon steel, stainless steel, high alloy steel. Copper steel can be used.

A base material has the unevenness | corrugation formed by projecting the ceramic type | mold projection material on the surface. The irregularities formed on the substrate have the same shape as the irregularities formed on the surface of the substrate in the above-described covering member. Therefore, the hard film formed on the unevenness is excellent in adhesion. This is particularly effective when using a hard film that is relatively easily peeled off, such as a carbon-based hard film.

  Further, due to the characteristic shape of the irregularities formed on the surface of the base material, even if the surface (sliding surface) is worn during use, the decrease in surface roughness is suppressed and the sliding characteristics are maintained. Specifically, as shown in the lower right diagram of FIG. 7, in conventional shot blasting using glass beads, the height of the convex portions is relatively uniform, so that the surface roughness increases as the surface wears during use. Becomes smaller. Since the clutch sliding member transmits torque by frictional engagement with the mating member, a reduction in surface roughness is inconvenient. On the other hand, when using a ceramic-based projection material, as described above, the height of the convex portion becomes an arbitrary height, so even if the surface is worn, the surface roughness is difficult to decrease. Reduction is suppressed. In addition, when the decrease in surface roughness is suppressed, the occurrence of shudder (vibration generated by stick-slip on the sliding surface) is also reduced.

  Therefore, the use of a ceramic-based projection material, particularly a substrate on which an alumina-based projection material is projected, improves the wear resistance (hard film adhesion) and shudder resistance of the sliding member for clutch. Reduction in dynamic characteristics is suppressed.

  Moreover, it is preferable that the surface of a base material is 2-6 micrometers Rz by 10-point average roughness (Rz), More preferably, it is 2.9-3.5 micrometers Rz. The clutch sliding member whose surface roughness of the base material is in the above range further improves the adhesion between the base material and the hard film.

  The hard film is formed integrally with the unevenness formed on the surface of the substrate, and at least a part of the hard film slides as a sliding surface. Here, the hard film refers to a film having a sliding surface surface hardness of about 1000 to 2500 Hv by Vickers hardness. Under the present circumstances, it is preferable that the surface roughness of a sliding surface is 2-6 micrometers Rz by 10-point average roughness (Rz), More preferably, it is 2.9-3.5 micrometers Rz. For example, if the direct current plasma CVD method is used as the method for forming the hard thin film, the surface roughness of the irregularities formed on the surface of the substrate is reflected well on the sliding surface. It can be a range. If the surface roughness of the sliding surface is within the above range, a frictional force suitable for torque transmission can be obtained.

  Moreover, it is preferable that the film thickness of a hard film is 1.5-8 micrometers, More preferably, it is 1.5-4.5 micrometers. If the hard film has a thickness in the above range, the peeling of the hard film can be satisfactorily reduced, and the wear resistance of the sliding surface can be exhibited well.

  The hard film is preferably a carbon hard film or a ceramic hard film. The carbon-based hard film is preferably an amorphous carbon film, a metal-containing carbon film, or a metal-containing carbonized film. An amorphous carbon film is suitable as a hard film for a sliding member for a clutch because of its low opponent attack and a high coefficient of friction in oil. The amorphous carbon film (DLC film) may be an amorphous carbon (DLC-Si) film containing silicon. Note that the ratio of silicon contained in the DLC-Si film is preferably 1% by weight to 80% by weight, more preferably 5% by weight to 50% by weight, and still more preferably 10% by weight to 40% by weight. As the metal-containing carbon film, a film obtained by adding titanium (Ti), chromium (Cr), or tungsten (W) to the DLC film can be used. As the metal-containing carbide film, a titanium carbide (TiC) film, a tungsten carbide (WC) film, a laminated film of a tungsten carbide film and a carbon film (WC / C), or the like can be used. Examples of the ceramic hard film include a titanium nitride (TiN) film and a chromium nitride (CrN) film.

  When the covering member of the present invention is a member that transmits torque by friction, when the carbon hard film is peeled off, the torque transmission property changes due to the change in surface properties. If the clutch sliding member of the present invention is a clutch plate used for an electromagnetic clutch, the pressing force of the clutch plate changes when the hard film is peeled off during use. The electromagnetic clutch transmits or discontinues torque by frictionally engaging / disengaging the clutch plate and the mating member with magnetic force. At this time, if the peeling of the hard film occurs, the strength of the magnetic flux passing through the electromagnetic clutch increases. As a result, the force for frictionally engaging the clutch plate and the mating member also increases, so that the transmitted torque value increases. In particular, since the carbon-based hard film is mostly non-magnetic, when the film is peeled off, the magnetic resistance changes and greatly affects the torque value. If the electromagnetic clutch has a hard film with excellent adhesion, the stability of the torque value can be maintained over a long period of time.

  Moreover, if the sliding member for clutches of this invention is a clutch board used for the wet clutch used in oil, the outstanding micro-v characteristic will be exhibited. The μ-v characteristic indicates the dependence of the coefficient of friction (μ) on the speed (v). In the clutch sliding member, the μ-v characteristic is a positive gradient (that is, dμ / dv ≧ 0). Is effective. However, when the surface roughness of the sliding member for the clutch is lowered during use, the effect of cutting the oil film generated on the sliding surface is reduced, and the solid contact is inhibited by the oil film formed on the sliding surface, and the μ-v characteristic. Has a negative slope. On the other hand, in the clutch sliding member of the present invention, as described above, even if the surface is worn, the surface roughness is difficult to be lowered. Exhibits -v characteristics.

[Manufacturing method of sliding member for clutch]
The manufacturing method of the clutch sliding member of this invention is a manufacturing method suitable for said clutch sliding member. The manufacturing method of the clutch sliding member of the present invention mainly includes a rough surface forming step and a hard film forming step.

  The rough surface forming step is the same as the above-mentioned [Manufacturing method of covering member]. Further, the hard film forming step is a step of forming a hard film that slides at least partially as a sliding surface on the uneven surface of the substrate formed in the rough surface forming step. The method for forming the hard film in the hard film forming step is the same as the above-mentioned [Manufacturing method of covering member].

Hereinafter, an embodiment of a manufacturing method of the clutches sliding member and a sliding member for a clutch of the present invention will be described with reference to FIG together with comparative examples.

[Example 1]
A pilot outer clutch plate of Example 1 (hereinafter referred to as “clutch plate of Example 1”) was produced by the following procedure.

  Shot blasting was performed on the surface of an iron pilot outer clutch plate (outer diameter 110 mm, inner diameter 70 mm, thickness 0.9 mm; FIG. 2 shows a plan view). Shot blasting uses an alumina-based projection material (Alundum (Norton Alumina) manufactured by Norton, particle size 50 to 90 μm), a projection pressure of 0.35 MPa, and a plate feed rate of 1.3 m / min. The surface roughness after shot blasting was 3.4 μm Rz.

  Next, a DLC-Si thin film was formed on the surface of the outer clutch plate roughened by shot blasting. The DLC-Si thin film was formed to a thickness of 3 μm by direct current plasma CVD.

  In addition, the scanning microscope (SEM) image which observed the cross section of the clutch plate of Example 1 in FIG. 3 is shown. The DLC-Si thin film is formed along the unevenness formed by shot blasting. Moreover, the surface roughness of the obtained clutch plate of Example 1 was 3.5 μm Rz.

  Here, with reference to FIG. 1, the electronic control coupling using the clutch plate of Example 1 is demonstrated. FIG. 1 is a cross-sectional view of a main part showing an electronic control coupling, and is a cross-sectional view of the main part when an electronic control coupling (hereinafter simply referred to as “driving force transmission device”) 10 is cut along a plane including the axis of the output shaft. It is. In addition, since the main part of the driving force transmission device 10 has a substantially symmetric configuration with respect to the axis, FIG. 1 shows substantially half of the driving force transmission device 10 and omits the other substantially half of the portion. is doing.

  The driving force transmission device 10 includes an outer case 10a, an inner shaft 10b, a main clutch 10c, a pilot clutch mechanism 10d, and a cam mechanism 10e. This driving force transmission device 10 is disposed in a driving force transmission path to the rear wheel side in a four-wheel drive vehicle.

  The outer case 10a constituting the driving force transmission device 10 is formed by a bottomed cylindrical housing 11a and a rear cover 11b fitted and screwed to a rear end opening of the housing 11a to cover the opening. . The housing 11a is made of an aluminum alloy that is a nonmagnetic material, and the rear cover 11b is made of iron that is a magnetic material. In addition, a stainless steel cylinder 11c, which is a nonmagnetic material, is embedded in the middle portion of the rear cover 11b, and the cylinder 11c forms an annular nonmagnetic part.

  The inner shaft 10b penetrates the central portion of the rear cover 11b in a liquid-tight manner and is coaxially inserted into the outer case 10a. The inner shaft 10b is rotatably supported by the housing 11a and the rear cover 11b with the axial direction regulated. Has been. A space that is liquid-tightly partitioned by the outer case 10a and the inner shaft 10b is filled with a lubricating oil composition.

  A tip portion of a second propeller shaft (not shown) connected to a differential device on the rear wheel side which is a driven wheel is inserted into the inner shaft 10b, and is connected so as to be able to transmit torque. Further, a first propeller shaft (not shown) connected to an output shaft of a transmission that changes the output of the engine is connected to a front end portion of the housing 11a constituting the outer case 10a so as to transmit torque. Note that the torque of the output shaft of the transmission is constantly transmitted to the front wheels, which are the main drive wheels, by a separate mechanism.

  The main clutch 10c is a wet multi-plate friction clutch, and includes a large number of iron clutch plates (a main inner clutch plate 12a and a main outer clutch plate 12b), and is disposed in the housing 11a. Each main inner clutch plate 12a constituting the main clutch 10c is assembled to the outer periphery of the inner shaft 10b by spline fitting so as to be movable in the axial direction, and each main outer clutch plate 12b is attached to the inner periphery of the housing 11a. It is assembled so that it can be moved in the axial direction by spline fitting. The main inner clutch plates 12a and the main outer clutch plates 12b are alternately positioned, abut against each other and frictionally engage with each other, and are separated from each other to be in a free state.

  In the main inner clutch plate 12a, a paper-based wet friction material (not shown) is attached to a portion that is in sliding contact with the main outer clutch plate 12b.

  The pilot clutch mechanism 10 d includes an electromagnet 13, a pilot clutch 14, an armature 15, and a yoke 16. The electromagnet 13 has an annular shape and is fitted in the annular recess 11d of the rear cover 11b while being fitted to the yoke 16. The yoke 16 is fixed to the vehicle body side while being rotatably supported by a bearing on the outer periphery of the rear end portion of the rear cover 11b.

  The pilot clutch 14 is a wet multi-plate friction clutch including a plurality of pilot outer clutch plates 14a and a pilot inner clutch plate 14b. Each pilot outer clutch plate 14a is spline-fitted to the inner periphery of the housing 11a and is axially moved. Each pilot inner clutch plate 14b is assembled so as to be movable in the axial direction by spline fitting on the outer periphery of a first cam member 17a constituting a cam mechanism 10e described later. . Each pilot inner clutch plate 14b has iron as a main component, and a special gas nitriding treatment is applied to the surface. On the sliding surface of each pilot inner clutch plate 14b, a large number of fine grooves (for example, a depth of 3 to 20 μm) extending in the circumferential direction are provided concentrically in parallel while maintaining a fine interval (for example, 100 to 300 μm). It has been. The pilot outer clutch plate 14a is the clutch plate of the present embodiment. A lubrication groove of a lattice groove for circulating the lubricating oil is formed on the sliding surface of the pilot outer clutch plate 14a.

  The armature 15 has an annular shape and is assembled to the inner periphery of the housing 11a by spline fitting so as to be movable in the axial direction, and is located on the opposite side of the electromagnet 13 with the pilot clutch 14 interposed therebetween.

  In the pilot clutch mechanism 10d having the above configuration, when the electromagnetic coil of the electromagnet 13 is energized, the magnetic flux circulating through the yoke 16, the rear cover 11b, the clutch plates of the pilot clutch 14 and the armature 15 is passed through the electromagnet 13 as a base point. The circulating magnetic path X is formed. The energization current of the electromagnet 13 is controlled to a predetermined current value set by duty control. In addition, a plurality of arc-shaped grooves are formed in portions corresponding to the cylinders 11c of the clutch plates of the pilot clutch 14 to prevent a short circuit of the magnetic flux.

  The energization of the electromagnetic coil of the electromagnet 13 is interrupted by a switch switching operation so that three drive modes to be described later can be selected. The switch is arranged in the vicinity of the driver's seat in the passenger compartment so that the driver can easily operate it. Note that if the driving force transmission device 10 is configured only in the second driving mode described later, the switch can be omitted.

  The cam mechanism 10e includes a first cam member 17a, a second cam member 17b, and a cam follower 17c. The first cam member 17a is rotatably fitted to the outer periphery of the inner shaft 10b, and is rotatably supported by the rear cover 11b. The pilot inner clutch plate 14b is spline-fitted to the outer periphery thereof. The second cam member 17b is spline-fitted to the outer periphery of the inner shaft 10b and assembled so as to be integrally rotatable, and is positioned opposite to the rear side of the main inner clutch plate 12a of the main clutch mechanism 10c. A ball-shaped cam follower 17c is interposed in the cam grooves of the first cam member 17a and the second cam member 17b facing each other.

  In the driving force transmission device 10 having such a configuration, when the electromagnetic coil of the electromagnet 13 constituting the pilot clutch mechanism 10d is in a non-energized state, no magnetic path is formed, and the friction clutch 14 is in a non-engaged state. Therefore, the pilot clutch mechanism 10d is in an inoperative state, the first cam member 17a constituting the cam mechanism 10e can rotate integrally with the second cam member 17b via the cam follower 17c, and the main clutch 10c Inactive state. For this reason, the vehicle constitutes a first drive mode that is a two-wheel drive.

  On the other hand, when the electromagnetic coil of the electromagnet 13 is energized, a loop-shaped circulation magnetic path X having the electromagnet 13 as a starting point is formed in the pilot clutch mechanism 10d, and a magnetic force is generated. Suction. For this reason, the armature 15 presses the friction clutch 14 and frictionally engages it. Then, the relative rotational torque between the housing 11a and the inner shaft 10b acts so as to relatively rotate the first cam member 17a and the second cam member 17b. As a result, in the cam mechanism 10e, the cam follower 17c presses both the cam members 17a and 17b away from each other.

  For this reason, the second cam member 17b is pushed toward the main clutch 10c, and presses the main clutch 10c with the back wall portion of the housing 11a so as to be frictionally engaged according to the friction engagement force of the friction clutch 14. As a result, torque is transmitted between the outer case 10a and the inner shaft 10b, and the vehicle has a second drive in which the first propeller shaft and the second propeller shaft are four-wheel drive between the non-direct connection state and the direct connection state. Configure the mode. In this drive mode, the driving force distribution ratio between the front and rear wheels can be controlled in a range from 100: 0 (two-wheel drive state) to a direct connection state according to the traveling state of the vehicle.

  In this second drive mode, duty control is performed on the current supplied to the electromagnetic coil in accordance with the running state of the vehicle and the road surface state based on signals from various sensors such as a wheel speed sensor, a throttle opening sensor, and a steering angle sensor. Thus, the friction engagement force of the friction clutch 14, that is, the transmission torque to the rear wheel side is controlled.

  Further, when the energization current to the electromagnetic coil of the electromagnet 13 is increased to a predetermined value, the attractive force of the electromagnet 13 with respect to the armature 15 is increased, and the armature 15 is strongly attracted to increase the frictional engagement force of the friction clutch 14, and both cams The relative rotation between the members 17a and 17b is increased. As a result, the cam follower 17c increases the pressing force with respect to the second cam member 17b to bring the main clutch mechanism 10c into the coupled state. For this reason, the vehicle constitutes a third drive mode that is a four-wheel drive in which the first propeller shaft and the second propeller shaft are directly connected.

[Example 2]
White alumina is used as the projection material, shot blasting conditions are an average particle size of projection material of 70 μm, a projection pressure of 0.25 MPa, a feed rate of 1.4 m / min, and a DLC-Si thin film thickness of 3.5 μm. Otherwise, the clutch plate of Example 2 was produced in the same manner as Example 1. The surface roughness of the base material after shot blasting of this clutch plate was 3 μm Rz.

[Example 3]
Black silicon carbide is used as the projection material, the shot blasting conditions are an average particle size of projection material of 70 μm, a projection pressure of 0.45 MPa, a feed rate of 1.3 m / min, and a DLC-Si thin film thickness of 2.9 μm. Otherwise, the clutch plate of Example 3 was produced in the same manner as in Example 1. The surface roughness of the base material after shot blasting of this clutch plate was 4 μm Rz.

[Comparative Example 1]
Glass beads are used as the projection material, the shot blasting conditions are an average particle size of projection material of 70 μm, a projection pressure of 0.35 MPa, a feed rate of 1.3 m / min, and a DLC-Si thin film thickness of 3 μm. The clutch plate of Comparative Example 1 was produced in the same manner as Example 1. The surface roughness of the base material after shot blasting of this clutch plate was 3.6 μm Rz.

[Comparative Example 2]
Comparison was made in the same manner as in Comparative Example 1 except that the shot blasting conditions were an average particle size of the projection material of 70 μm, a projection pressure of 0.55 MPa, a feed rate of 1.3 m / min, and a DLC-Si thin film thickness of 3 μm. The clutch plate of Example 2 was produced. The surface roughness of the base material after shot blasting of this clutch plate was 5 μm Rz.

[Comparative Example 3]
The shot blasting conditions were the same as in Comparative Example 1 except that the average particle size of the projection material was 70 μm, the projection pressure was 0.45 MPa, the feed rate was 1.3 m / min, and the thickness of the DLC-Si thin film was 2.9 μm. Thus, a clutch plate of Comparative Example 3 was produced. The surface roughness of the base material after shot blasting of this clutch plate was 4 μm Rz.

[Comparative Example 4]
Comparison was made in the same manner as in Comparative Example 1 except that the shot blasting conditions were an average particle size of the projection material of 70 μm, a projection pressure of 0.65 MPa, a feed rate of 1.3 m / min, and a DLC-Si thin film thickness of 3 μm. The clutch plate of Example 4 was produced. The surface roughness of the base material after shot blasting of this clutch plate was 5.5 μm Rz.

[Comparative Example 5]
Comparison was made in the same manner as in Comparative Example 1 except that the shot blasting conditions were an average particle diameter of the projection material of 70 μm, a projection pressure of 0.25 MPa, a feed rate of 1.3 m / min, and a DLC-Si thin film thickness of 3 μm. The clutch plate of Example 5 was produced. The surface roughness of the base material after shot blasting of this clutch plate was 3.1 μm Rz.

  In Examples 2 and 3 and Comparative Examples 1 to 5, there was almost no surface roughness before and after the DLC-Si film was formed.

[Evaluation]
[Evaluation of adhesion]
A Rockwell indentation test was performed on the clutch plates of Example 1 and Comparative Example 1. The test was performed on a Rockwell C scale with an indentation load of 150N. The periphery of the indentation formed on the surface after the test was observed with a scanning electron microscope (SEM). An SEM image is shown in FIG.

  In the clutch plate of Example 1, peeling of the DLC-Si thin film was not observed around the indentation (see the upper diagram of FIG. 4). On the other hand, in the clutch plate of Comparative Example 1, peeling of the DLC-Si thin film was observed around the indentation (see the lower diagram of FIG. 4).

[Durability evaluation of driving force transmission device]
With respect to the driving force transmission device using the clutch plates of the above examples and comparative examples as the pilot outer clutch plate 14a, the torque change rate and the shudder life ratio before and after the durability were calculated, and the durability was evaluated.

  FIG. 5 is a graph showing a torque change with respect to the adhesion force of the DLC-Si thin film when each of the clutch plates of Examples 1 to 3 and Comparative Examples 1 to 5 is used as a pilot clutch of the driving force transmission device. At this time, the surface pressure of the clutch plate was 0.3 MPa, the average sliding speed was 0.1 m / s, and the surface temperature of the driving force transmission device was 90 ° C. The horizontal axis indicates the adhesion force of the DLC-Si thin film, and the adhesion force increases toward the right. The vertical axis shows the relative torque change, and the torque value before and after endurance increases as it goes upward. Further, in FIG. 5, the clutch plate of the example (projected by alundum) is indicated by ▲, and the clutch plate of the comparative example (projected by glass beads) is indicated by ◯.

  According to FIG. 5, in the clutch plates of Comparative Examples 1 to 5, the hard thin film peeled off from the plate surface during the operation of the driving force transmission device, and the torque value under a certain condition before and after the endurance changed greatly. On the other hand, since the clutch plates of Examples 1 to 3 were excellent in adhesion, torque change before and after durability was reduced.

  FIG. 6 is a graph showing a shudder life ratio when the clutch plates of Example 1 and Comparative Example 1 are used in a driving force transmission device. According to FIG. 6, the shudder life of Example 1 was three times that of Comparative Example 1. Therefore, the driving force transmission device using the clutch plate of Example 1 is excellent in the μ-v characteristic.

It is principal part sectional drawing of an electronically controlled coupling (driving force transmission device). The top view of the pilot outer clutch plate of an Example and a comparative example is shown. 2 is an SEM image obtained by observing a cross section of a pilot outer clutch plate of Example 1. FIG. It is a SEM image which shows the result of the Rockwell impression test of the pilot outer clutch plate of Example 1 and Comparative Example 1. It is a graph which shows the torque change with respect to the adhesive force of a hard thin film (DLC-Si thin film) at the time of using each pilot outer clutch plate of Examples 1-3 and Comparative Examples 1-5 for a driving force transmission apparatus. It is a graph which shows a shudder lifetime ratio at the time of using the pilot outer clutch plate of Example 1 and Comparative Example 1 for a driving force transmission device. It is a figure which shows typically the cross section of the base material which performed shot blasting, Comprising: The upper figure shows the case where an alumina type projection material is projected, and the lower figure shows the case where a glass bead is projected. It is a graph which shows the relationship between the projection pressure of the alumina type projection material in a rough surface formation process, and the surface roughness (Rz) of the projected base material.

Explanation of symbols

10: Electronically controlled coupling (driving force transmission device)
14: Pilot clutch 14a: Pilot outer clutch plate 14b: Pilot inner clutch plate X: Circulating magnetic path

Claims (21)

A clutch sliding member that transmits torque by friction,
A metal base having projections and depressions formed by projecting a ceramic-based projection material on the surface, a hard film that is integrally formed along the projections and slides at least partially as a sliding surface, I have a,
Sliding member clutch surface roughness of the sliding surface, characterized in 2~6μmRz der Rukoto a ten-point average roughness.   The sliding member for a clutch according to claim 1, wherein a distance from the tip of the convex portion to the tip of the adjacent convex portion when the unevenness of the base material is viewed in plan is 3 to 30 µm. The clutch sliding member according to claim 1 or 2, wherein the sliding surface has a ten-point average roughness of 2.9 to 3.5 µmRz. The said hard film | membrane is a sliding member for clutches in any one of Claims 1-3 which has a film thickness of 1.5-8 micrometers.   The clutch-based sliding member according to any one of claims 1 to 4, wherein the ceramic-based projection material has a plurality of ridge angles on a surface thereof. The sliding member for a clutch according to any one of claims 1 to 5, wherein the ceramic-based projection material is an alumina-based projection material containing alumina. The clutch hard member according to claim 1, wherein the hard film is a carbon-based hard film or a ceramic-based hard film. The clutch sliding member according to claim 7 , wherein the carbon-based hard film is an amorphous carbon film or a metal-containing carbon film. The clutch sliding member according to any one of claims 1 to 8, wherein the clutch sliding member is a clutch plate used for an electromagnetic clutch. The clutch sliding member according to any one of claims 1 to 8, wherein the clutch sliding member is a clutch plate used in a wet clutch used in oil. A method of manufacturing a clutch sliding member that transmits torque by friction,
Forming a rough surface by projecting a ceramic-based projection material onto the surface of a metal substrate to form irregularities, and forming a hard film that slides at least partially as a sliding surface along the irregular surface and the hard film forming step of, Tona is, the production method of a sliding member for a clutch, characterized in 2~6μmRz and to Rukoto surface roughness ten-point average roughness of the sliding surface.   The method for manufacturing a sliding member for a clutch according to claim 11, wherein the rough surface forming step is a step of projecting a ceramic projection material having a particle diameter of 50 to 90 μm. The method for producing a sliding member for a clutch according to claim 11 or 12 , wherein the rough surface forming step is a step of projecting a ceramic-based projection material at a pressure of 0.15 to 0.7 MPa. The method for manufacturing a sliding member for a clutch according to claim 13 , wherein the rough surface forming step is a step of projecting the ceramic-based projection material at a pressure of 0.25 to 0.35 MPa.   The method for manufacturing a clutch sliding member according to any one of claims 11 to 14, wherein the ceramic-based projection material has a plurality of ridge angles on a surface thereof. The method for manufacturing a sliding member for a clutch according to any one of claims 11 to 15, wherein the ceramic-based projection material is an alumina-based projection material containing alumina. The method for manufacturing a sliding member for a clutch according to claim 11, wherein the hard film is a carbon-based hard film or a ceramic-based hard film. The method of manufacturing a sliding member for a clutch according to any one of claims 11 to 17, wherein the hard film forming step is a step of forming a carbon-based hard film by a direct current plasma CVD method. The method of manufacturing a clutch sliding member according to claim 17 or 18 , wherein the carbon-based hard film is an amorphous carbon film or a metal-containing carbon film. The method for manufacturing a clutch sliding member according to any one of claims 11 to 19, wherein the clutch sliding member is a clutch plate used in an electromagnetic clutch. The method for manufacturing a sliding member for a clutch according to any one of claims 11 to 19, wherein the sliding member for a clutch is a clutch plate used for a wet clutch used in oil.

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