JP2006258149A - Combined slide member - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide combined slide members not only improving wear resistance of the both combined slide members sliding to each other but also improving slide characteristics of the combined members in comprehensive consideration of the slide characteristics such as seize resistance, friction action on the counterpart member and friction coefficients of the both slide members. <P>SOLUTION: The combined slide members have a groove part 21 of a hub sleeve 20 in which a slide surface is formed with a film composed of amorphous carbon material, and pawls 13 of a shift fork 10 that are formed with surface hardened layers of surface hardness of from Hv 1000 to Hv 2000 by oxidation treatment of aluminum material or its alloy material on slide surfaces sliding with the slide surface of the groove part 21 of the hub sleeve 20. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a combination slide in which a member formed with a film made of an amorphous carbon material on the surface and a member made of an aluminum material or an alloy material thereof on the sliding surface of the member and the sliding surface are combined. The present invention relates to a moving member, and more particularly to a combination sliding member that improves the sliding characteristics of the sliding surfaces of these members.

  Conventionally, sliding members have been used in various devices such as engines and transmissions in automobiles, and various developments have been made to improve the sliding characteristics of the sliding members.

  For example, a shift fork of a vehicle transmission as shown in FIGS. 4 and 5 has been proposed as a sliding member with improved sliding characteristics. The shift fork 10 of the transmission 100 is engaged with the groove portion 21 of the hub sleeve 20 rotating at high speed in accordance with the operation of the shift lever (not shown) by the driver, and this groove portion in the direction of the output shaft 50 is engaged. 21 is pressed. By this pressing, the rotation of the output shaft 50 is synchronized via the synchronizer ring 30 and power can be transmitted to the gear 40.

  Such a shift fork 10 has a fork portion 12 branched from the base end portion 11 in a bifurcated manner. The fork portion 12 includes a claw portion 13 at the tip thereof, and the claw portion 13 contacts the groove portion 21 of the hub sleeve 20 that rotates at a high speed during the pressing. Therefore, in order to improve the wear resistance of the claw part 13, the claw part 13 covers the sliding surface 13a with a plating film in which ceramic fine particles are dispersed in nickel or an alloy thereof (see Patent Document 1). .

  In addition to this, in order to improve the wear resistance of the sliding member, a cylinder made of an aluminum alloy containing Si, a piston ring whose surface is coated with diamond-like carbon (amorphous carbon material), A combination sliding member combining the above has been proposed (see Patent Document 2).

JP-A-1-42580 JP 2001-280497 A

  However, in the case of the transmission as described above, for example, the purpose is to improve the wear resistance of the sliding surface of the shift fork claw, and the shift fork claw and the hub sleeve groove Therefore, the seizure resistance, the opponent aggression, and the friction coefficient are not considered.

  That is, if the seizure part of the shift fork against the groove part of the hub sleeve is high and the attack of the other party is large, both the claw part of the shift fork and the groove part of the hub sleeve will be worn. There is a possibility that the backlash is sometimes increased and the shift is lost.

  Further, if the frictional force between the claw portion of the shift fork and the groove portion of the hub sleeve is large (the friction coefficient is large), the shift operating force with which the shift fork presses the hub sleeve also increases, which may deteriorate the shift feeling.

  The present invention has been made in view of such problems, and the object of the present invention is not only to improve the wear resistance of both of the combination sliding members that slide on each other, but also to slide both of them. It is an object of the present invention to provide a combined sliding member capable of improving the sliding characteristics of the combined members by comprehensively considering the sliding characteristics such as seizure resistance of the members, opponent attack, and friction coefficient.

  The present inventors have conducted many experiments and researches to solve the above problems, and as a combination of materials having good slidability, an amorphous carbon material (diamond-like carbon) and an aluminum material are formed on the surface. Or the combination with the alloy material is excellent, and furthermore, by providing an oxide film with a predetermined hardness on the sliding surface of the aluminum material or the alloy material, the sliding characteristics of the sliding surfaces of both members are revolutionary. I got the knowledge that it would improve.

  The present invention is based on the above-mentioned new knowledge obtained by the present inventors, and the combined sliding member of the present invention includes a first member in which a coating made of an amorphous carbon material is formed on a sliding surface. And a second member in which a hardened surface layer having a surface hardness of Hv1000 to Hv2000 is formed by oxidizing an aluminum material or an alloy material thereof on the sliding surface of the first member and the sliding surface of the first member. It is characterized by that.

  As in the present invention, by using a combination of a film of an amorphous carbon material and an oxide film (surface hardened layer by oxidation treatment) of an aluminum material or an alloy material having a surface hardness in the range of Hv1000 to Hv2000, sliding is achieved. The mutual wear resistance of the members is improved, not only the life of the members is extended, but also the surface seizure property and the opponent attack property are reduced, and the friction coefficient is also reduced.

  When the surface hardness of the surface hardened layer of the aluminum material or the alloy material of the second member is smaller than Hv1000, the coating of the amorphous carbon material of the first member promotes the wear of the surface hardened layer of the second member, Furthermore, if the surface hardness of the surface hardened layer is higher than Hv2000, the surface hardened layer promotes the wear of the amorphous carbon material film.

  Moreover, it is preferable that the oxidation process of the 2nd member of this combination sliding member is a plasma electrolytic oxidation process. Thus, by performing plasma electrolytic oxidation treatment on the sliding surface of the aluminum material or aluminum alloy material of the second member, a hardened surface layer having a surface hardness of Hv1000 to Hv2000 as described above can be easily formed. be able to.

  Furthermore, when performing such plasma electrolytic oxidation treatment, the surface after this treatment has a surface roughness that increases with surface hardening, so in order to further improve the sliding characteristics of this combined sliding member, It is preferable to reduce the surface roughness by polishing the oxidized surface.

  Furthermore, the surface hardness of the amorphous carbon material coated on the first member of the combination sliding member is preferably Hv1000 to Hv5000. By setting the surface hardness in such a range, the first member and the first member The wear resistance of both the two members can be improved.

  Further, when the first member is coated with the amorphous carbon material, a layer made of chromium (Cr) is provided as an intermediate layer between the base material of the first member and the coating. It is possible to improve the adhesion. Further, titanium (Ti) or tungsten (W) may be used instead of the chromium.

  By setting the surface hardness of such an amorphous carbon material, the sliding characteristics of the first member and the second member can be further improved. When the surface hardness of the amorphous carbon material is Hv 1000 or less, the coating of the amorphous carbon material is greatly worn by the cured surface of the surface hardened layer of the second member. When the surface hardness of the second member is Hv5000 or more, the surface hardened layer of the second member is greatly worn by the coating of the amorphous carbon material.

  The surface roughness of the amorphous carbon material coated on the first member of the combination sliding member is preferably 10-point average roughness Rz 0.5 μm or less.

  By making the surface roughness in this range, the seizure resistance of the combined sliding member is improved, the friction coefficient is reduced, the wear amount of the first member and the second member is also reduced, and the sliding characteristics are further improved. Can be made. That is, when the surface roughness of the amorphous carbon material of the first member is larger than the ten-point average roughness Rz 0.5 μm, this surface promotes wear of the surface hardened layer of the aluminum material of the second member or its alloy material. As a result, the life as a combination sliding member is reduced.

  Such a combination is possible because the thickness of the hardened surface layer (thickness of the oxide film) obtained by oxidizing the aluminum material or its alloy material can be made larger than the film thickness of the amorphous carbon material. When the sliding member is used for the transmission shown above, the first member of the combined sliding member is used for the sliding surface of the groove portion of the hub sleeve constituting the transmission, and the second member of the combined sliding member is used. The member is preferably used for the sliding surface of the claw portion of the shift fork.

  As described above, since the aluminum material or its alloy material having a thick surface hardened layer is used for the claw portion of the shift fork having a large amount of wear, the life of the shift fork is extended and the amorphous carbon material is further coated. Since the groove portion of the hub sleeve is not easily worn, as a result, the life of the combined sliding member can be extended.

  According to the present invention, the sliding properties of the sliding members are improved by improving various properties such as wear resistance, seizure resistance, opponent attack, and friction coefficient of the sliding members that slide. be able to. As a result, by using the sliding member, it is possible to prevent damage to the device due to seizure or wear of the sliding surface, and to extend the life of the device body.

  Hereinafter, the present invention will be described by way of examples. The present embodiment is an embodiment in which the combination sliding member according to the present invention is used for a vehicle transmission (see FIG. 4), and the first member of the combination sliding member according to the present invention is used as a slide of the hub sleeve of the transmission. This is an embodiment in which the second member is used for the sliding surface of the shift fork.

Example 1
A shift fork as shown in FIG. 5 was manufactured from an aluminum alloy casting (JIS: AC9C). And the nail | claw part of this shift fork is arrange | positioned in the electrolyte solution which mixed potassium hydroxide and water in the ratio of the weight of 1: 6, bath temperature 40 degreeC, processing voltage 620V, and current density 5A / dm < ² >. Under conditions, a surface hardened layer (oxide film) having a layer thickness of 100 μm was formed on the surface of the nail portion of this shift fork by plasma electrolytic oxidation (PEO).

  On the other hand, the hub sleeve was made of chromium molybdenum steel (JIS: SCM420). Further, this steel was carburized and hardened, and the sliding surface of the groove portion contacting the claw portion of the shift fork was coated with 0.5 μm of chromium, and further, the amorphous carbon material (DLC) film was coated on the chromium layer. Was coated (coated) with a film thickness of 2 μm. The DLC film was formed using a source gas: methane gas and an atmosphere gas: argon gas under the conditions of a substrate temperature of 200 ° C. and a bias voltage of 100 V. DLC film formation may be performed by either PVD processing or CVD processing.

  Furthermore, in order to perform the seizure test described later, as a test piece corresponding to the claw material of the shift fork, an inner diameter of 20 mm, an outer diameter of 25.6 mm, a height of 17 mm, a ten-point average roughness Rz 1.6 μm, a cylindrical test piece Produced. Further, as a test piece corresponding to the groove portion material of the hub sleeve, a flat plate test piece having a size of 30 × 30 × 5 mm and an average roughness Rz of 0.5 μm was manufactured.

  And the abrasion test was done with respect to the combination sliding member which consists of the shift fork and hub sleeve of Example 1. FIG. Specifically, these components are incorporated into an actual transmission and filled with a lubricant (ATF Dexron II), and the shift fork under the conditions of a hub sleeve rotation speed of 4800 rpm, an oil temperature of 120 ° C., and a shift fork operating load of 100 kg. The claw part of the fork is operated for 1 sec (contacted with the hub sleeve) -1.5 sec pause (not contacted with the hub sleeve), and this is defined as one cycle, and 3000 cycles are carried out. The amount of wear of the groove (abrasion length in the axial direction) was measured.

  Further, a seizure test was performed on the combined sliding members. Specifically, using a cylindrical test piece (claw part material) and a flat plate test piece (groove part material), while performing splash lubrication using a lubricant (ATF Dexron II) by a mechanical laboratory type abrasion friction tester, The cylindrical test piece (claw material) was rotated at 8600 rpm (circumferential speed 9.6 m / sec), the pressing load was increased by 250 N every 2 minutes, and pressed against the flat plate test piece (groove material). Then, the load when the friction coefficient became 0.2 or more or when the wear became extremely large was measured as a seizure load, and the friction coefficient was also obtained. The surface hardness of the claw part of the shift fork and the surface hardness of the groove part of the hub sleeve were measured.

  The results of this wear test and seizure test are shown in FIG.

  As shown in Table 1 and FIG. 1, the seizure load of the combined sliding member is 4250 N, the friction coefficient is about 0.01, the wear amount of the claw part of the shift fork is 20 μm, and the groove part of the hub sleeve is There was almost no wear. The surface hardness of the claw part of the shift fork was Hv1500, and the surface hardness of the groove part of the hub sleeve was Hv3000.

(Comparative Example 1)
A shift fork and a hub sleeve having the same shape as in Example 1 were prepared. The difference from Example 1 is that the shift fork is manufactured from chrome steel (JIS: SCr420) and then carburized and quenched.

(Comparative Example 2)
A shift fork and a hub sleeve having the same shape as in Example 1 were prepared. The difference from Example 1 is that the shift fork is manufactured from chrome steel (JIS: SCr420), then carburized and quenched, and the sliding surface of the shift fork after carburizing and quenching is coated with hard chrome plating.

(Comparative Example 3)
A shift fork and a hub sleeve having the same shape as in Example 1 were prepared. The difference from the first embodiment is that the DLC is not coated after the carburizing and quenching of the hub sleeve.

(Comparative Example 4)
A shift fork and a hub sleeve having the same shape as in Example 1 were prepared. The difference from the first embodiment is that the shift fork is manufactured from chrome steel (JIS: SCr420) and then carburized and quenched, and the hub sleeve is carburized and quenched and is not covered with DLC.

(Comparative Example 5)
A shift fork and a hub sleeve having the same shape as in Example 1 were prepared. The difference from Example 1 is that the shift fork is manufactured from chrome steel (JIS: SCr420), then carburized and hardened, and the sliding surface of the shift fork after carburizing and hardening is coated with hard chrome plating, and the hub After the carburizing and quenching of the sleeve, the DLC is not covered.

  Then, the wear test and seizure test were performed on the combination sliding members of Comparative Examples 1 to 5 in the same manner as in Example 1. The results are shown in FIG.

  As shown in Table 1 and FIG. 1, the combined sliding members of Comparative Examples 1 to 5 had a higher coefficient of friction and a smaller seizure load than Example 1. In addition, both the claw part of the shift fork and the groove part of the hub sleeve had a larger amount of wear than Example 1.

(Evaluation 1)
From this result, as in Example 1, an amorphous carbon material (DLC) and an aluminum alloy whose surface was hardened by plasma electrolytic oxidation treatment were used in combination with the sliding member. It is considered that not only the mutual wear resistance was improved and the life of each member was prolonged, but also the seizure property of the surface and the opponent attack were reduced, and the friction coefficient was also reduced.

  In addition, if the material is mainly aluminum, the surface can be hardened by oxidation treatment, so it is estimated that similar results can be obtained even when aluminum is used instead of an aluminum alloy. Is done.

(Examples 2 to 5)
A combination sliding member similar to that in Example 1 was manufactured. The difference from the first embodiment is that the oxidation treatment was performed under the voltage conditions as shown in Table 2 below as the treatment voltage during the plasma electrolytic oxidation treatment of the claw portions of the shift forks of the second to fifth embodiments.

  About the combination sliding member shown to these Examples 2-5, the abrasion test similar to Example 1 was done. Moreover, the surface hardness of the surface hardened layer of the nail | claw part of these shift forks was also measured. The results are shown in FIG.

  As shown in FIG. 2 and Table 2, the surface hardness of the surface hardened layer of the claw portion of the shift fork increased as the processing voltage was increased. Further, the wear amount of the claw portion of the shift fork of the combination sliding member of Examples 2 to 5 was 40 μm or less, and the wear amount of the groove portion of the hub sleeve was 5 μm or less.

(Comparative Examples 6 and 7)
A combination sliding member similar to that in Example 1 was manufactured. The difference from Example 1 is that the oxidation treatment was performed under the voltage conditions as shown in Table 2 for the plasma electrolytic oxidation treatment voltage on the surface of the claw portion of the shift fork of Comparative Examples 6 and 7.

  About the combination sliding member shown to these comparative examples 6 and 7, the abrasion test similar to Example 1 was done. Moreover, the surface hardness of the surface hardened layer of the nail | claw part of these shift forks was also measured. The results are shown in FIG.

  As shown in FIG. 2 and Table 2, the surface hardness of the claw portion of the shift fork of Comparative Example 6 was 800 Hv, and the wear amount of the claw portion of the shift fork was large compared to Examples 2 to 5. Further, the surface hardness of the claw portion of the shift fork of Comparative Example 7 was 2500 Hv, and the wear amount of the groove portion of the hub sleeve of Comparative Example 7 was large as compared with Examples 2 to 5.

(Evaluation 2)
From this result, the optimum surface hardness of the surface hardened layer of the claw portion of the shift fork is Hv1000 to Hv2000, and if the surface hardness range is exceeded, wear of either the claw portion of the shift fork or the groove portion of the hub sleeve will occur. Think to promote. That is, when the surface hardness of the claw part of the shift fork is smaller than Hv1000 as in Comparative Example 6, the wear of the claw part of the shift fork is promoted by the DLC coating on the groove part of the hub sleeve. When the surface hardness of the claw portion is higher than Hv2000, it is considered that the wear of the groove portion of the hub sleeve is promoted by the claw portion of the shift fork.

(Examples 6 and 7)
A combination sliding member similar to that in Example 1 was manufactured. The difference from the first embodiment is that the surface roughness of the groove portion of the hub sleeve before coating the DLC is adjusted, and the surface roughness of the DLC coating formed on the groove portion of the hub sleeve of the sixth and seventh embodiments is sequentially increased to ten points. The average roughness Rz is 0.1 μm and 0.5 μm.

  And the same abrasion test as Example 1 was performed with respect to the combination sliding member of Example 6 and 7, Furthermore, the test piece corresponding to these was manufactured similarly to Example 1, and the seizure test was done. . The results are shown in FIG.

  3 and Table 3, even when the surface roughness of the DLC film was changed as in Example 6 and Example 7, the seizure load was about 4250 N and the friction coefficient was 0 as in Example 1. The wear amount of the claw portion of the shift fork was about 20 μm, and the wear amount of the groove portion of the hub sleeve was almost zero.

(Comparative Examples 8 to 10)
A combination sliding member similar to that in Example 1 was manufactured. The difference from Example 1 is that the roughness of the groove portion of the hub sleeve before coating the DLC is adjusted, and the surface roughness of the DLC coating formed on the groove of the hub sleeve is changed to the ten-point average roughness Rz1 μm in order from Comparative Example 8. The point is 3 μm and 5 μm.

  Then, the same sliding test as in Example 1 was performed on the combination sliding members of Comparative Examples 8 to 10, and further, test pieces corresponding to these were manufactured and the seizure test was performed as in Example 1. . The results are shown in FIG.

  As shown in FIG. 3 and Table 3, even if the surface roughness of the DLC film coated on the groove portion of the hub sleeve is increased, the wear amount of the groove portion of the hub sleeve hardly changes, but the shift that presses the groove portion of the hub sleeve is changed. The amount of wear on the fork pawls increased, the seizure load of the combined sliding member decreased, and the friction coefficient increased.

  In addition, the combination sliding members of Comparative Examples 8 to 10 had a larger amount of wear on the claw portion of the shift fork, a smaller seizure load as a sliding member, and a larger coefficient of friction than Examples 6 and 7. .

(Evaluation 3)
From these results, it is preferable that the surface roughness of the DLC coated on the groove portion of the hub sleeve is 10 points average roughness Rz 0.5 μm or less. If this surface roughness is larger than this, the shift fork that contacts the groove portion of the hub sleeve It is considered that the amount of wear of the claw portion of the claw is increased due to the abrasive wear, and the sliding resistance of these members is also increased.

  Although the example of the combination sliding member of this embodiment is used for a shift fork and a hub sleeve of a vehicle transmission, such as a sliding member of an engine piston ring and a cylinder, the sliding frequency is high and wear resistance. It is particularly suitable for a sliding member used in an environment in which is required.

The figure which showed the abrasion test result of the combination sliding member of Example 1, and the combination sliding member of Comparative Examples 1-5. The figure which showed the abrasion test result of the combination sliding member of Examples 2 to 5 and the combination sliding member of Comparative Examples 6 and 7. The figure which showed the abrasion test result of the combination sliding member of Example 6 and 7 and the combination sliding member of Comparative Examples 8-10. The figure which showed the transmission of the conventional vehicle. The figure which showed the shift fork of the transmission shown in FIG.

Explanation of symbols

10: Shift fork, 13: Claw, 20: Hub sleeve, 21: Groove, 100: Transmission

Claims (5)

  A first member having a coating made of an amorphous carbon material formed on the sliding surface, and an aluminum material or an alloy material thereof is oxidized on the sliding surface that slides with the sliding surface of the first member. And a second member on which a hardened surface layer having a surface hardness of Hv2000 is formed.   The combination sliding member according to claim 1, wherein the oxidation treatment of the second member is a plasma electrolytic oxidation treatment.   The combined sliding member according to claim 1 or 2, wherein the amorphous carbon material coated on the first member has a surface hardness of Hv1000 to Hv5000.   4. The combined sliding member according to claim 1, wherein the surface roughness of the amorphous carbon material coated on the first member is a ten-point average roughness Rz of 0.5 μm or less. 5.   A transmission using the combination sliding member according to any one of claims 1 to 4, wherein a first member of the combination sliding member is used on a sliding surface of a hub sleeve constituting the transmission, A transmission characterized in that a second member of a combination sliding member is used on the sliding surface of the shift fork.

Images