JP2005308080A - Sliding device, shift operation device - Google Patents

Abstract

The present invention provides a sliding device and a speed change operation device that improve wear resistance, reduce a friction coefficient, reduce opponent attack, and improve seizure resistance.
An enlarged sectional view of a fitting portion between a shift fork claw portion and a hub sleeve groove portion is shown. The shift fork claw part 29 has a Co base metal layer 30 on the surface of which a Co base metal containing 10 to 50% of eutectic carbide is formed on the surface, and the surface of the hub sleeve groove 32 is A diamond-like carbon layer (DLC layer) having a surface on which a diamond-like carbon layer having a hardness of 1000 to 5000 in terms of Hv value is formed, and the surface roughness (Rz) of the diamond-like carbon layer is 0.5 μm or less ) 33.
[Selection] Figure 4

Description

  The present invention includes a sliding device, a speed change operation device, and in particular, a first sliding member and a second sliding member that slides with the first sliding member, and the first sliding member and the second sliding member. The present invention relates to a sliding device and a speed change operation device that include a sliding action that slides on each other via a sliding surface of the surface.

  As one of gear shifting operation devices such as vehicles, a shift fork sandwiched by a hub sleeve is fitted to a fork shaft interlocking with a shift lever so as to be movable in a certain amount in the axial direction, and connected to the shift fork via a fork shaft. A speed change operation device is known. This speed change operation device includes a shift fork that sandwiches the hub sleeve by fitting the hub sleeve and its claw portion with a groove portion of the hub sleeve. A part of these fitting portions becomes a sliding surface, and by the sliding action of sliding, the operating force of the claw portion of the shift fork is transmitted to the groove portion of the hub sleeve, and the hub sleeve moves.

  If the surface of the claw part of the shift fork or the groove part of the hub sleeve that becomes the sliding surface is worn, there is a case where the shift operation becomes loose at the time of the vehicle shift, and the shift slip is likely to occur. Usually, the frictional force between the surface of the claw portion of the shift fork and the surface of the groove portion of the hub sleeve becomes the pressing force of the spline fitting portion of the hub and hub sleeve. From this relationship, the magnitude of the friction force, that is, the magnitude of the friction coefficient affects the magnitude of the shift operation force. Therefore, when the friction coefficient between the surface of the claw part of the shift fork and the groove part of the hub sleeve becomes high, the shift feeling may be deteriorated. As described above, these materials are problems from the viewpoint of such surface wear and friction coefficient.

  Various background technologies have been reported for the material of the surface of the claw portion of the shift fork that becomes the sliding surface and the material of the surface of the groove portion of the hub sleeve. For example, on the surface of the claw part of the shift fork, the material steel (for example, chromium steel of SCr420) subjected to induction hardening treatment, soft nitriding, gas soft nitriding treatment, hard chrome plating, ceramic dispersion Ni Those subjected to anti-plating treatment such as -P plating are known. In addition, a material obtained by quenching the same steel is also known as a material for the surface of the groove portion of the hub sleeve.

  For example, Patent Documents 1 and 2 listed below disclose a structure in which a wear-resistant sprayed layer such as Mo or a hypereutectic Al—Si alloy is formed on the surface of the shift fork claw. Patent Documents 3 and 4 listed below disclose a shift fork claw surface formed by coating or impregnating polyamide resin, fluorine resin, or the like. Patent Document 5 below discloses a shift fork claw surface formed of a composite material of a fiber and an Al alloy.

  Patent Document 6 below discloses a valve in which an alloy having a eutectic carbide in a Co-based alloy is mounted on the surface.

JP 58-64523 A Japanese Examined Patent Publication No. 62-8807 JP-A-58-97718 Japanese Patent Laid-Open No. 56-16218 JP 62-32925 A JP 2002-97913 A

  However, regarding the material of the surface of the claw part of the shift fork and the material of the surface of the groove part of the hub sleeve, it is necessary to further improve these characteristics such as improvement of wear resistance and friction coefficient.

  Further, in order to improve the wear resistance and reduce the friction coefficient, it is necessary to improve the seizure resistance and to reduce the opponent attack. If the opponent's aggressiveness is great, they will wear each other. In addition, when seizure occurs, the surface becomes rough, the opponent attack becomes greater, and wear resistance is reduced. In the present application, the opponent aggression refers to the wearability of the mating counterpart member. That is, if the surface of the shift fork claw is the surface that wears the surface of the hub sleeve groove, the surface of the hub sleeve is the surface that wears the surface of the shift fork claw. A characteristic that wears the surface of a part.

  Therefore, it is necessary to consider the characteristics that indirectly characterize these characteristics of improving wear resistance and reducing the friction coefficient, and it is necessary to consider the above comprehensive characteristics including the characteristics that are indirectly characterized. Necessary.

  Furthermore, not only the material of the surface of the claw part of the shift fork and the surface of the groove part of the hub sleeve, but also the sliding device in general including the sliding action that slides through the sliding surface of the surface. There is a need to provide materials for sliding parts that improve properties.

  The present invention has been made in view of solving at least one of the above-mentioned problems, and improves wear resistance, reduces a coefficient of friction, reduces opponent attack, and improves seizure resistance. It is an object of the present invention to provide a sliding device and a speed change operation device.

  The present invention includes a first sliding member and a second sliding member that slides on the first sliding member, and the first sliding member and the second sliding member slide on the surface of each other. A sliding device including a sliding action that slides through a surface, wherein a cobalt base metal containing 10 to 50% of eutectic carbide in an area ratio is provided on a sliding surface of the first sliding member. Surface-formed, a diamond-like carbon layer having a hardness of 1000 to 5000 in terms of Hv value is formed on the sliding surface of the second sliding member, and the surface roughness (Rz) of the diamond-like carbon layer ) Is 0.5 μm or less.

  The present invention has a hub sleeve, and a shift fork that sandwiches the hub sleeve by fitting the claw portion of the hub sleeve with the groove portion of the hub sleeve, and operates the claw portion of the shift fork on the surface of the fitting portion. A speed change operation device in which force is transmitted to the hub sleeve by a sliding action with the groove portion of the hub sleeve, and at least the surface of the fitting portion Co foundation metal layer to which the operation force is transmitted, The claw part surface of the shift fork is formed with a cobalt base metal containing 10 to 50% of eutectic carbide in area ratio, and the groove part surface of the hub sleeve has a hardness of 1000 to 5000 in terms of Hv value. A like carbon layer is formed on the surface, and the surface roughness (Rz) of the diamond like carbon layer is 0.5 μm or less.

  In the above speed change operation device, it is preferable that the diamond-like carbon layer is formed on a steel hub sleeve groove steel substrate.

  In the above speed change operation device, it is preferable that an adhesion auxiliary layer is provided between the hub sleeve groove steel member and the diamond-like carbon layer.

  INDUSTRIAL APPLICABILITY The present invention can provide a sliding device and a speed change operation device that improve wear resistance, reduce a friction coefficient, reduce opponent attack, and improve seizure resistance.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. This embodiment is an example for carrying out the present invention, and the present invention is not limited to this embodiment. In the present embodiment, the gear shifting operation device is described as an example of a synchronous mesh gear shifting operation device mounted on a vehicle.

  FIG. 1 shows a part of the internal structure of a synchronous mesh type speed change operation device 11 mounted on a vehicle. The speed change operation device 11 includes an input shaft 12 and an output shaft 13 that are arranged on the same straight line. The input shaft 12 is connected to a crankshaft of an internal combustion engine mounted on the vehicle via a clutch or the like (not shown). The output shaft 13 is connected to driving wheels (all not shown) via a drive shaft, a differential gear, an axle, and the like, and the rotation of the output shaft 13 is transmitted to the driving wheels through these members.

  A gear (also called a main drive gear) 14 is integrally provided on the input shaft 12. A plurality of gears 15 (also called speed gears) 15 having different numbers of teeth are rotatably provided on the output shaft 13. A counter gear 17 having a plurality of gears 16 is arranged in parallel to the input shaft 12 and the output shaft 13. The gear 16 of the counter gear 17 meshes with the corresponding one of the gears 14 and 15.

  A plurality of hubs 18 are spline-fitted on the output shaft 13. (In FIG. 2, the spline between the output shaft 13 and the hub 18 is not shown.) On the outer periphery of each hub 18, a hub sleeve 19 slides in the axial direction (left-right direction in FIG. 1). Spline fitting is possible. When each hub sleeve 19 is not engaged with any of the gears 14 and 15, each gear 15 idles on the output shaft 13, and power transmission from the input shaft 12 to the output shaft 13 is interrupted. . That is, the shift operation device 11 is in a neutral state.

  On the other hand, when the hub sleeve 19 moves in the axial direction and meshes with any of the gears 14 and 15, the rotation of the internal combustion engine causes the input shaft 12, the counter gear 17, the gears 14 and 15, the hub sleeve 19, the hub 18 and the like. Is transmitted to the output shaft 13. Then, by engaging the hub sleeve 19 with the different gears 14 and 15, the combination of the gears 14 to 17 related to power transmission is switched to perform a shift.

  2 and 3 are partially enlarged views of the speed change operation device. The transmission operating device 11 is provided with a transmission mechanism 21 for transmitting an operation force accompanying a shift operation of the driver to the hub sleeve 19. The transmission mechanism 21 includes a plurality of fork shafts 22 and a shift fork 23 for each fork shaft 22. Each fork shaft 22 is supported by a bearing (not shown) so as to be capable of reciprocating in an axial direction (a direction orthogonal to the paper surface in FIG. 2 and a left-right direction in FIG. 3). Each shift fork 23 is fastened to the corresponding fork shaft 22 by a bolt 24 or the like. The fork shaft 22 and the shift fork 23 move in the axial direction to slide the hub sleeve 19 in the same direction. The shift fork 23 has a shift fork claw portion 29 for fitting with the hub sleeve 19 at its tip.

  A hub sleeve groove 32 having a width wider than the thickness of the shift fork claw portion 29 is formed on the outer peripheral portion of the hub sleeve 19 over the entire circumference. When the shift fork 23 enters the hub sleeve groove 32, the shift fork claw 29 and the hub sleeve groove 32 are fitted, and by this fitting structure, the operating force of the shift fork claw is applied to the groove of the hub sleeve. As a result, the hub sleeve 19 moves.

  FIG. 4 shows an enlarged cross-sectional view of the fitting portion between the shift fork claw portion 29 and the hub sleeve groove portion 32 in FIG. As a feature of the present embodiment, the shift fork claw portion 29 has a Co base metal layer 30 on its surface, and the hub sleeve groove portion 32 surface has a diamond-like carbon layer (DLC layer) 33 on its surface. ing. (In addition, in FIGS. 1-3, illustration of these surface layers is abbreviate | omitted for convenience of explanation.)

  In the speed change operation device 11, a synchronizing mechanism 25 is incorporated in order to make the peripheral speeds of the hub sleeve 19 and the gear 15 (14) coincide with each other. The synchronization mechanism 25 has the same configuration as that generally used, and includes a synchronizer ring 26, a shifting key 27, and the like in addition to the hub 18 and the hub sleeve 19 described above. . The synchronizer ring 26 is covered on the cone (cone) portion 28 of the gear 15 (14) so as to be slidable in the axial direction. The shifting key 27 is engaged with a groove provided on the outer periphery of the hub 18 and is pressed against the hub sleeve 19 by an elastic member (not shown) such as a C ring or a spring.

  In the synchronization mechanism 25, when the shift fork 23 moves the hub sleeve 19 in the direction of the arrow X in FIG. 3, for example, in accordance with the driver's shift operation, the hub sleeve 19 and the shifting key 27 are engaged at the projection. Therefore, the force applied to the hub sleeve 19 is transmitted to the shifting key 27. By this transmission, the shifting key 27 presses the synchronizer ring 26 against the cone portion 28. By this pressing, a frictional force is generated between the cone portion 28 and the synchronizer ring 26, and the rotation of the gear 15 (14) starts to rise. When the hub sleeve 19 further moves in the same direction, the hub sleeve 19 and the shifting key 27 are disengaged. Then, the spline on the inner periphery of the hub sleeve 19 hits the teeth of the synchronizer ring 26, and the synchronizer ring 26 is pressed against the cone portion 28 with a strong force, and a strong synchronizing (synchronizing) action is exerted. Eventually, the peripheral speed of the gear 15 (14) coincides with the peripheral speed of the hub sleeve 19, the two mesh with each other, and the gear 15 (14) is locked to the output shaft 13 so as not to be relatively rotatable. In this way, the input shaft 12 and the output shaft 13 are drivingly connected.

  The shift fork claw portion 29 has a Co base metal layer 30 formed on the surface thereof with a thickness of 0.5 mm. The Co foundation metal layer 30 (the stellite 12-containing layer) is made of stellite 12 (Co solid solution) and eutectic carbide.

  Table 1 shows a component table of the stellite 12 according to the present embodiment. It is shown as a weight% (wt%) amount in the stellite 12. The stellite 12 contains Co other than C, Si, Mn, Cr, Mo, W, Fe, and Ni.

  The eutectic carbide contained in the Co base metal layer 20 together with the stellite 12 is contained on the surface of the Co base metal layer 30 so as to be deposited on the surface layer by 30% with respect to the entire area. In this specification, “area ratio X%” means that the area ratio occupies X% of the entire surface. Although observation of the surface is not particularly limited, for example, an optical microscope may be used.

  The manufacturing method of the shift fork nail | claw part 29 which has such a Co foundation metal layer 30 is as follows. A shift fork claw steel substrate 31 having the shape of the shift fork claw 29 is manufactured. This claw part steel substrate 31 is made of chromium steel (SCr420), and is surface-treated by carburizing and quenching. Co base metal containing eutectic carbide is deposited on the surface of the claw steel substrate 31 to form a Co base metal layer 30 before surface flattening. At this time, depositing is performed so that the thickness is slightly greater than 0.5 mm (500 μm).

  The surface of the Co base metal containing eutectic carbide as it is deposited is flattened and finished. For the flattening of the surface, a toolman whose blade is made of steel is used as a cutting tool. The surface layer is shaved with this blade to flatten the surface of the Co foundation metal. Finished by this surface flattening step, a Co base metal layer 30 having a thickness of 0.5 mm and containing 30% eutectic carbide by area is finally formed on the surface.

  The range of the area ratio of the eutectic carbide in the Co foundation metal layer 30 is 10 to 50%. If the area ratio is less than 10%, the surface strengthening effect due to the hardness of the eutectic carbide cannot be obtained, and the wear resistance of the Co base metal layer 30 on the surface of the shift fork claw portion 29 is reduced. . On the other hand, if the area ratio exceeds 50%, the Co base metal layer 30 may become too hard and brittle. Furthermore, if the Co base metal layer 30 becomes too hard, the cutting tool tends to be worn during surface flattening, which is not practical from the viewpoint of the balance between the life of the cutting tool and the high cost. Furthermore, if the Co foundation metal layer 30 becomes too hard, the opponent attack will increase, and the amount of wear of the DLC layer 33 on the surface of the hub sleeve groove 32 will increase.

  Co foundation money is expensive, and as the amount of use increases, the shift fork becomes expensive. Therefore, it is preferable to suppress the thickness of the deposit in a range that can be suppressed to an inexpensive price, and to flatten the surface of the deposit with a cutting tool. As a specific example, it is preferable that the thickness is increased to be a little over 0.5 mm, and the thickness of the Co base deposit layer 30 after the surface flattening is set to 0.5 mm.

  On the other hand, the hub sleeve groove 32 has a DLC layer 33 formed on its surface with a thickness of 2 μm. The DLC layer 33 has a surface roughness Rz of 0.5 μm or less. What is necessary is just to measure this surface roughness using a normal surface roughness meter. The hardness of the DLC layer 33 formed on the surface is Hv: 3000. Between the DLC layer 33 and the steel substrate on the surface of the hub sleeve groove portion, an intermediate layer 34 mainly composed of Cr is provided as an adhesion auxiliary layer in order to improve surface adhesion.

  The manufacturing method of the hub sleeve 19 having such a DLC layer 33 is as follows. A hub sleeve groove steel substrate 35 having the shape of the hub sleeve groove 32 is manufactured. This groove steel substrate 35 is made of steel (SCM420) and has been surface-treated by carburizing and quenching. The surface roughness (Rz) of the grooved steel substrate 35 is subjected to a surface polishing treatment as necessary so as to be 0.5 μm or less.

The Cr intermediate layer 34 is provided with a thickness of 0.5 μm on the surface of the grooved steel substrate 35 having a surface roughness (Rz) of 0.5 μm or less. A film is formed on the surface of the grooved steel substrate 35 provided with the intermediate layer 34 by a PVD vapor deposition method, and a DLC layer 33 having a thickness of 2 μm, a surface roughness of 0.5 μm or less, and a hardness of Hv: 3000 is provided. Here, as film formation conditions by the PVD vapor deposition method, the surface temperature of the grooved steel substrate 35 is 200 ° C., the bias voltage is 200 V, and Ar gas and CH ₄ gas are used as gases.

  The surface roughness (Rz) of the DLC layer 33 is 0.5 μm or less. When Rz exceeds 0.5 μm, the wear amount of the Co base metal layer 30 on the surface of the shift fork claw 29 increases due to the opponent attack of the DLC layer 33, and the wear resistance of the DLC layer 33 itself decreases. The amount of wear may increase. Furthermore, if Rz exceeds 0.5 μm, seizure resistance may be reduced, and the friction coefficient may be increased.

  The surface roughness (Rz) of the grooved steel substrate 35 before the intermediate layer 34 is provided is preferably 0.5 μm. The groove surface layer, which is a combination of the DLC layer 33 and the intermediate layer 34, generally has to be made thinner than the Co base metal layer 30 on the surface of the shift fork claw 29. This is due to various reasons such as a risk of cracking when the DLC layer 33 is thickened, and cost. Therefore, although it is normal to make it thin, when such thinning is performed, the surface roughness of the base of the grooved steel substrate 35 before providing the intermediate layer 34 affects the surface roughness of the grooved surface layer. Therefore, if the substrate is rough, it may affect the surface roughness of the DLC layer 33, and it may be difficult to make the surface roughness (Rz) of the surface of the DLC layer 33 0.5 μm or less. Therefore, it is necessary that the surface of the grooved steel substrate 35 before providing the intermediate layer 34 be as flat as possible. Specifically, the surface roughness (Rz) is preferably 0.5 μm.

  The intermediate layer 34 is not limited to a layer containing Cr as a main component, and may be any layer that improves the adhesion between the DLC layer 33 and the surface of the grooved steel substrate 35, such as Ti or W. There may be. Further, the intermediate layer 34 is not necessarily required if there is sufficient adhesion between the DLC layer 33 and the surface of the grooved steel substrate 35.

  The hardness of the DLC layer 33 is Hv: 1000 to 5000. If it is smaller than 1000, the surface strengthening effect due to the hardness cannot be obtained, and the wear amount of the DLC layer 33 becomes large. If the Hv is larger than 5000, the attacking ability of the opponent increases, and the wear amount of the Co foundation metal layer 30 on the surface of the shift fork claw 29 increases. Also, it may become too hard and brittle.

  The Co foundation metal layer 30 on the surface of the shift fork claw 29 and the DLC layer 33 on the surface of the hub sleeve groove 32 are not necessarily formed on the entire surface. What is necessary is just to be formed in the contact part of the surface of the shift fork nail | claw part 29 and the hub sleeve groove part 32 where the operating force of the shift fork nail | claw part 29 is transmitted to the groove part of the said hub sleeve.

  The thicknesses of the Co foundation metal layer 30 on the surface of the shift fork claw 29 and the DLC layer 33 on the surface of the hub sleeve groove 32 are appropriately changed according to the embodiment. For example, DLC is superior in wear resistance and the like to Stellite 12, but it is Stellite 12 that can thicken the layer. As a result of comparing the possibility of increasing the thickness of the layer with the wear resistance, Stellite 12 Sometimes thickening is chosen.

  An example of the selection will be given according to this embodiment. The surface of the hub sleeve groove 32 rotates during the operation of the speed change operation device, and the surface of rotation rotates with the same portion of the surface of the shift fork pawl 29. The surface of the hub sleeve groove 32 rotates and a different surface of the hub sleeve groove 32 always slides with the surface of the shift fork claw 29, but the surface of the shift fork claw 29 always slides with the surface of the hub sleeve groove 32 on the same surface. Since the ratio of the sliding area is different, the surface of the shift fork claw portion 29 is easily worn, and as a result of comparing the balance between the possibility of increasing the thickness of the layer and the wear resistance, the Co foundation metal layer 30 is The surface of the shift fork claw portion 29 is selected.

  In the present embodiment, the Co foundation metal layer 30 is formed on the surface of the shift fork claw portion 29 and the DLC layer 33 is formed on the surface of the hub sleeve groove portion 32 under the above-mentioned predetermined conditions. In addition to the surface of the hub sleeve groove 32, the present invention can be generally applied to a sliding device including a sliding action of sliding through the sliding surfaces of the surfaces. For example, there is a cobalt base metal containing 10 to 50% of eutectic carbide in an area ratio on the sliding surface of one sliding member of a sliding member that is a sliding portion of an engine valve. A diamond-like carbon layer having a surface with a hardness of 1000 to 5000 in terms of Hv value and a surface roughness (Rz) of 0.5 μm or less is formed on the surface of the other sliding member. You can adopt what you have.

  Using the shift fork claw part and the hub sleeve groove part, an implementation test was conducted with a speed change operation device on various characteristics of wear resistance, opponent attack, friction coefficient, and seizure resistance.

  In this example, a wear test (actual machine wear test) under mild conditions that did not cause seizure was performed using the shift fork and the hub sleeve using the speed change operation device of the embodiment. Specifically, a shift fork and a hub sleeve are incorporated into the speed change operation device of the embodiment, filled with lubricating oil (ATF Dexron II), a hub sleeve rotation speed of 4800 rpm, an oil temperature of 120 ° C., and a shift fork operating load of 100 kg. Then, 3000 cycles of 1 sec operation-1.5 sec pause were carried out, and the amount of wear on the surface of the shift fork claw portion and the surface of the hub sleeve groove was investigated.

  The seizure test was performed by producing a cylindrical test piece (shift fork claw surface material) and a flat plate test piece (hub sleeve groove surface material) for friction and wear tests. The cylindrical test piece had an inner diameter of 20 mmφ, an outer diameter of 25.6 mmφ, a height of 17 mm, and a surface roughness of 1.6 μm Rz. The flat plate test piece had a length of 30 × width of 30 × height of 5 mm and a surface roughness of 0.5 μm Rz. A seizure test for obtaining a seizure load was performed using a cylindrical test piece and a flat plate test piece under these conditions.

  This seizure test uses a mechanical laboratory type friction and wear tester and increases the load by 250 N every 2 minutes under the condition of splash lubrication with lubricating oil (ATF Dexron II) and 8600 rpm (9.6 m / sec). I went. The seizure load was defined as the seizure load when the friction coefficient was 0.2 or more, or when the wear was extremely large visually.

  In this example, unless otherwise specified, the “example” refers to a combination of a shift fork pawl portion and a hub sleeve groove portion manufactured by the manufacturing method according to the above-described embodiment. That is, the shift fork claw portion of the embodiment has a Co base metal layer formed on the surface with a thickness of 0.5 mm, and this Co base metal layer (the stellite 12-containing layer) is as shown in Table 1 above. A surface layer made of stellite 12 as a component and eutectic carbide containing 30% in area ratio is formed. Further, the hub sleeve groove portion of the embodiment has a DLC layer with a thickness of 2 μm formed on the surface thereof, and the DLC layer has a surface roughness Rz of 0.5 μm or less, and the surface-formed DLC layer has a hard surface. The height is Hv: 3000. Furthermore, between this DLC layer and the steel base material on the surface of the hub sleeve groove portion, an intermediate layer having a thickness of 0.5 μm mainly composed of Cr is provided as an adhesion auxiliary layer in order to improve surface adhesion. Yes.

  The main evaluation criteria in this example are as follows. It is determined that the seizure load is 3000 N or more. It is determined that the friction coefficient is preferably 0.02 or less. It is judged that the amount of wear on the surface of the shift fork claw is preferably 50 μm or less. The amount of wear on the surface of the hub sleeve groove is determined to be 2 μm or less.

(1) Actual machine wear test (material change)
This test was performed by changing the combination of the material of the shift fork claw surface and the hub sleeve groove surface.

  The shift fork claw part used as a comparative example is a claw part base material surface (SCr420: carburized and quenched) (i) having a Co foundation metal layer formed on the surface in the same manner as in this example, (ii) Three types were used: one in which the Co base metal layer was not formed on the surface and the hard chrome plating was formed on the surface, and (iii) the surface of the nail part base material was left as it was without the Co base metal layer being formed on the surface. . Other conditions are the same as in the example.

  The hub sleeve groove used as a comparative example is a groove base material surface (SCM420: carburized and quenched), (i) a DLC layer formed on the surface in the same manner as in this example, and (ii) a DLC layer formed on the surface. Instead, two types of the groove base material surface as they were were used. Other conditions are the same as in the example.

"Results and Evaluation"
FIG. 5 shows the results of this test. It was found that the wear resistance of both the shift fork claw surface and the hub sleeve groove surface can be improved with the combination of the examples. Since this wear resistance can be improved, it has been found that both the shift fork claw surface and the hub sleeve groove surface can also reduce the partner attack.

(2) Actual machine wear test (change in surface roughness)
This test was performed by changing the combination of the materials of the shift fork claw surface and the hub sleeve groove surface. Other conditions are the same as in the example.

"Results and Evaluation"
The results of this test are shown in FIG. It was found that the surface roughness of the example was able to reduce the opponent attack and improve the wear resistance on both the shift fork claw surface and the hub sleeve groove surface. That is, it was found that when the surface roughness Rz exceeds 0.5 μm, the amount of wear increases on both the shift fork claw surface and the hub sleeve groove surface (particularly the shift fork claw surface).

(3) Seizure test (change in material)
This test was performed by changing the combination of the cylindrical test piece (claw surface material) and the flat plate test piece (groove surface material).

  The cylindrical test piece used as a comparative example is a claw part base material surface (SCr420: carburized and quenched) (i) a Co foundation metal layer formed on the surface in the same manner as in this example. (Ii) Co Three types were used: the surface of the base metal layer was not formed, the surface of the hard chromium plating was formed, and the surface of the nail part base material was left as it was (iii) the surface of the Co base metal layer was not formed. Other conditions are the same as in the example.

  The flat plate test piece used as a comparative example has (i) a DLC layer formed on the surface of a groove base material (SCM420: carburized and quenched), and (ii) a DLC layer formed on the surface. Instead, two types of the groove base material surface as they were were used. Other conditions are the same as in the example.

"Results and Evaluation"
The results of this test are shown in Table 2. It was found that with the combination of the examples, both the surface of the shift fork claw and the surface of the hub sleeve groove can improve the seizure resistance and reduce the friction coefficient.

(4) Seizure test (change in surface roughness)
In this test, a test was performed by changing the combination by changing the surface roughness of the flat plate test piece (groove surface material). The comparative example differs only in the surface roughness, and the other conditions are the same as in the example.

"Results and Evaluation"
The results of this test are shown in Table 3. It was found that the surface roughness of the example was able to improve the seizure resistance and reduce the friction coefficient on both the shift fork claw surface and the hub sleeve groove surface.

(5) Actual machine wear test (change in eutectic carbide content)
In this test, a test using a shift fork claw portion and a hub sleeve groove portion by changing the combination by changing the content of the eutectic carbide in the Co base metal on the surface of the shift fork claw portion by the area ratio was performed. Table 4 shows the content of the eutectic carbide of the Co base metal and the ratio of each metal component other than Co in the stellite 12 (% by weight). Metals not listed in the table have the same content as in Table 1.

"Results and Evaluation"
Table 5 and the corresponding FIG. 7 show the results of this test. It was found that the wear resistance of the surface of the shift fork claw can be improved when the area ratio of the eutectic carbide in the Co base metal is 10% or more.

(6) Cutting tool life test (change in eutectic carbide content)
In this test, a blade life test was carried out using a blade that flattened the surface by shaving the foundation metal layer. A ring-shaped Co foundation metal sample in which the eutectic carbide content is changed corresponding to the component table 4 of the Co foundation metal layer is used. The cutting tool of the embodiment actually used is used as the cutting tool. The ring-shaped Co foundation metal sample has an inner diameter of 30 mmφ and an outer diameter of 50 mmφ.

  In FIG. 8, the ring-shaped Co foundation metal sample is rotated at a rotational speed of 100 rpm, the cutting tool is fed into the inner ring part at 1 mm / sec, the inner ring part is cut to 50 μm, the cutting is stopped, and the cutting tool is moved back to the original position. Returned to position.

  The above-described series of steps from feeding the cutting tool to stopping the cutting and returning it to the original position was defined as the number of times the cutting tool was fed once, and the number of feeding times until the flank wear amount of the cutting tool reached 20 μm was defined as the life feeding number. When the number of times of life feeding was less than 500, it was determined that the amount of wear of the blade was large and the blade life was short.

"Results and Evaluation"
FIG. 9 shows the results of this test. It was found that when the area ratio of the eutectic carbide in the Co foundation metal was 50% or less, the life feeding frequency could be 500 times or more, and the tool life could be secured. From the results of the above (5) actual machine wear test (eutectic carbide content change) and the result of this test, it was found that the Co base metal layer preferably contained 10-50% of the eutectic carbide in area ratio. .

It is explanatory drawing which shows the speed change operation apparatus which concerns on this embodiment. It is a partial expanded sectional view of the speed change operation apparatus concerning this embodiment. It is a partial expanded sectional view of the speed change operation apparatus concerning this embodiment. It is an expanded sectional view of the shift fork nail | claw part and hub sleeve groove part which concern on this embodiment. It is a graph which shows the result of the actual machine abrasion test concerning a present Example. It is a graph which shows the result of the actual machine abrasion test concerning a present Example. It is a graph which shows the result of the actual machine abrasion test concerning a present Example. It is explanatory drawing of the blade tool life test which concerns on a present Example. It is a graph which shows the result of the blade tool life test concerning a present Example.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 11 Shift operation apparatus, 19 Hub sleeve, 21 Transmission mechanism, 23 Shift fork, 25 Synchronous mechanism, 29, Shift fork claw part, 30 Co foundation metal layer, 31 Claw part steel base material, 32 Hub sleeve groove part, 33 DLC layer , 34 Intermediate layer, 35 Groove steel base.

Claims (4)

A first sliding member and a second sliding member that slides with the first sliding member, wherein the first sliding member and the second sliding member are connected to each other via a sliding surface on the surface thereof; A sliding device including a sliding action to slide,
On the sliding surface of the first sliding member, a cobalt base metal containing 10 to 50% of eutectic carbide in an area ratio is formed on the surface,
A diamond-like carbon layer having a hardness of 1000 to 5000 in terms of Hv value is formed on the sliding surface of the second sliding member, and the surface roughness (Rz) of the diamond-like carbon layer is 0. A sliding device that is 5 μm or less. A hub sleeve and a shift fork for fitting the claw portion with the groove portion of the hub sleeve to sandwich the hub sleeve, and the operation force of the claw portion of the shift fork on the surface of the fitting portion is the hub. A shift operation device that is transmitted to the hub sleeve by a sliding action with a groove portion of the sleeve,
At least the surface of the fitting portion to which the operating force is transmitted,
Cobalt foundation metal containing 10-50% of eutectic carbide in area ratio is formed on the surface of the claw part of the shift fork,
The surface of the groove of the hub sleeve is formed with a diamond-like carbon layer having a hardness of 1000 to 5000 in Hv value, and the surface roughness (Rz) of the diamond-like carbon layer is 0.5 μm or less. Operating device. The shift operation device according to claim 2, wherein
The diamond-like carbon layer is a gear shifting operation device formed by coating a steel hub sleeve groove steel substrate. The shift operation device according to claim 3, wherein
A speed change operation device in which a close adhesion auxiliary layer is provided between the hub sleeve groove steel substrate and the diamond-like carbon layer.

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