JPH08218179A - Wear resistant sliding member - Google Patents

Abstract

PURPOSE: To provide a wear resistant sliding member which excels in wear resistance under high surface bearing pressure and has low attackability to an opposite material and excels in seizure resistance and keeps a coefficient of friction high. CONSTITUTION: A wear resistant coating film 6 in which 8-20wt.% Ni3 B (or 10-60wt.% Ni3 P) is contained in a coating film base material consisting essentially of Ni is formed on the surface of a sliding part 4 of a synchronizer ring of a manual transmission of an automobile.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wear resistant sliding member, and more particularly to a high friction wear resistant sliding member suitable for a synchronizer ring of an automobile transmission.

[0002]

2. Description of the Related Art With the increase in output of automobile engines, cylinder liners, piston rings, friction sliding surfaces of transmission synchronizer rings, wet friction plates of multiple disc clutches of transmissions, etc. are used under higher surface pressure. These sliding members are required to have further improved wear resistance and seizure resistance. For example, the synchronizer ring has conventionally been composed of a copper-zinc alloy, but recently, in order to improve wear resistance and seizure resistance, molybdenum sprayed on the sliding surface of the synchronizer ring has been applied. It's starting. On the other hand, Japanese Patent Publication No. 58-10986 discloses a sliding member in which a thermal spray coating made of 2 to 30% by weight of molybdenum and the balance aluminum alloy or copper alloy is formed on the surface of the sliding portion of the base material. .

[0003]

In the case of the synchronizer ring made of the copper-zinc alloy, the hardness is relatively low and the friction coefficient is low, so that it is inferior in quick fastening property under a high load condition, and has a large wear amount and is durable. There are problems such as lack of sex. In the synchronizer ring formed with the sprayed molybdenum coating, although the wear resistance of molybdenum itself is high, since molybdenum is very hard as Hv 700, the aggressiveness against the mating material is high and the wear amount of the mating material increases, There are problems such as lack of durability, compression under high surface pressure and wear of the mating material to smooth the surface and reduce the friction coefficient. An object of the present invention is to provide a wear resistant sliding member which has excellent wear resistance under high surface pressure, low attacking property against a mating material, excellent seizure resistance, and can maintain a high friction coefficient.

[0004]

A wear-resistant sliding member according to claim 1, wherein a surface of a sliding portion of the sliding member contains Ni ₃ B in a predetermined weight ratio in a coating base material containing Ni as a main component. It is formed with a wear resistant film. The wear-resistant sliding member according to claim 2,
A wear-resistant coating containing 8 to 20% by weight of Ni ₃ B on a coating base material containing Ni as a main component is formed on the surface of the sliding portion of the sliding member. The wear-resistant sliding member according to claim 3, wherein a wear-resistant coating containing a predetermined weight ratio of Ni ₃ P on a coating base material containing Ni as a main component is formed on the surface of the sliding portion of the sliding member. Is. The wear-resistant sliding member according to claim 4, wherein a wear-resistant coating containing 10 to 60% by weight of Ni ₃ P on a coating base material containing Ni as a main component is formed on the sliding portion surface of the sliding member. It was done.

A wear-resistant sliding member according to claim 5 is the wear-resistant sliding member according to claim 1.
The invention according to any one of claims 4 to 4, wherein the wear resistant coating is a coating formed by a plating treatment. A wear resistant sliding member according to a sixth aspect of the present invention is the invention according to any one of the first to fourth aspects, wherein the wear resistant coating is a coating formed by thermal spraying. According to a seventh aspect of the present invention, in the abrasion-resistant sliding member according to the second or fourth aspect of the invention, the sliding member is a synchronizer ring for an automobile transmission. According to an eighth aspect of the present invention, in the wear-resistant sliding member according to the seventh aspect, the base material of the sliding member is made of an alloy of Cu and Zn.

[0006]

According to the wear-resistant sliding member of the present invention, the surface of the sliding portion of the sliding member is made of a coating material containing Ni as a main component and containing Ni ₃ B in a predetermined weight ratio. An abradable film is formed. Since it is a coating base material containing Ni as the main component, it has excellent seizure resistance, and since it is a wear-resistant coating containing a predetermined weight ratio of Ni ₃ B, it has excellent wear resistance due to Ni ₃ B with high hardness. High friction coefficient can be maintained.

In the wear-resistant sliding member according to claim 2,
The seizure resistance is the same as in claim 1, because a wear-resistant coating containing 8 to 20% by weight of Ni ₃ B is formed on a coating base material containing Ni as a main component on the surface of the sliding portion of the sliding member. With excellent wear resistance, the friction coefficient can be maintained high. Here, if Ni ₃ B is less than 8% by weight, the friction coefficient decreases due to friction with the counterpart material,
If the load capacity decreases and Ni ₃ B exceeds 20% by weight, the aggressiveness of the Ni ₃ B with high hardness to the mating material increases, the wear amount of the mating material increases, and the durability decreases. However, the hardness tends to be locally high, and the seizure resistance is also reduced.

In the wear-resistant sliding member according to claim 3,
On the surface of the sliding portion of the sliding member, a wear-resistant coating containing Ni ₃ P in a predetermined weight ratio on a coating base material containing Ni as a main component is formed. Since it is a coating base material containing Ni as a main component, it has excellent seizure resistance, and since it is a wear-resistant coating containing a predetermined weight ratio of Ni ₃ P, it has excellent wear resistance due to high hardness Ni ₃ P. High friction coefficient can be maintained.

In the wear-resistant sliding member according to claim 4,
The seizure resistance is the same as that of claim 3, since a wear-resistant coating containing 10 to 60% by weight of Ni ₃ P is formed on the coating base material containing Ni as a main component on the surface of the sliding portion of the sliding member. With excellent wear resistance, the friction coefficient can be maintained high. Where Ni ₃ P is 10
Is less than weight percent, and reduced coefficients of friction with the mating member, to load capacity is reduced, and if Ni ₃ P is 60 wt.%, The aggressiveness against the mating member by Ni ₃ P of high hardness Not only does this increase the wear amount of the mating material and reduce the durability, but also the hardness tends to be locally high and the seizure resistance is also reduced.

In the wear-resistant sliding member according to claim 5,
The same action and effect as in any one of claims 1 to 4 are achieved, but since the abrasion resistant coating is a coating formed by plating, the coating can be easily and economically uniform. Can be formed. The wear-resistant sliding member according to claim 6 has the same action and effect as any one of claims 1 to 4, but the wear-resistant coating film is formed by thermal spraying. Therefore, the coating can be formed easily and economically.

In the wear-resistant sliding member according to claim 7,
The same action and effect as claim 2 or claim 4 are achieved,
Since the sliding member is a synchronizer ring for an automobile transmission, a high-performance synchronizer ring having a coating film having a large friction coefficient and excellent wear resistance and seizure resistance on the sliding surface is obtained. In the wear-resistant sliding member according to claim 8, in the invention according to claim 7, the base material of the sliding member is C.
Since it is made of an alloy of u and Zn, a conventional base material made of an alloy of Cu and Zn can be used as the base material of the synchronizer ring.

[0012]

Embodiments of the present invention will be described below with reference to the drawings. The present embodiment is an example in which the present invention is applied to a synchronizer ring of a manual transmission of an automobile. As shown in FIG. 1, synchronizer ring 1
Is a ring-shaped steel member, and a plurality of tooth portions 2 are formed on the outer peripheral portion of the synchronizer ring 1, which are frictionally fitted and fastened to a clutch cone (not shown) which is a mating member. The fitting hole 3 is formed, and the tapered inner peripheral surface of the fitting hole 3 is a sliding portion 4 which is fitted to the tapered portion of the clutch cone by external fitting.

As shown in the enlarged view of FIG. 2, a spiral triangular groove 5 is formed on the sliding portion 4 in order to reduce the sliding area and increase the surface pressure. An abrasion resistant coating 6 having a thickness of several 10 μm (for example, 30 to 80 μm) is formed on the surface. This wear-resistant coating 6 is made of Ni
8 for a coating base material in which B (boron) is solid-solved in (nickel)
It is a film in which ˜20 wt% of Ni ₃ B (nickel boride) is dispersed and deposited, and this wear-resistant film is formed by plating as described later.

Next, in order to confirm various properties such as the friction coefficient, wear resistance, and seizure resistance of the wear resistant coating 6, and in order to check the proper Ni ₃ B content weight ratio, The method and the result of the experiment conducted under the condition which is as close as possible to the synchronizer ring 1 will be described. As the test piece, a ring test piece corresponding to the mating member (clutch cone) and a disk test piece corresponding to the synchronizer ring 1 were used.

1] Ring test piece The material of the ring test piece 10 shown in FIGS. 4 and 5 is SCR420.
H (Carburized material), its shape and dimensions are as shown in the figure,
The unit of dimensions in the figure is mm. 2] Disc test piece The material of the base material of the disc test piece 20 shown in FIGS.
It is a copper-zinc alloy, and its shape and dimensions are as shown in the figure, and the unit of the dimension in the figure is mm. Disc test piece 2
Radial shallow grooves 22 at 45 degree intervals on the sliding surface 21 of 0
(See FIG. 7) are formed, and spiral triangular grooves 23 are formed in portions other than these shallow grooves 22 in order to reduce the sliding area and increase the surface pressure, as shown in an enlarged view in FIG.

3] Abrasion resistant coating of disc test piece A disc test piece 20 with no abrasion resistant coating formed on the sliding surface 21 and one with a plurality of types of abrasion resistant coating formed as follows. Created in. Comparative Example 1 ... No film formation (described as Cu-Zn in the figure) Comparative Example 2 ... Mo (molybdenum) spraying (film thickness 30μ
m) Example of this plan ... Precipitation hardening Ni plating film (film thickness 30μ
m) with B as a solid solution and 0,8,17,25% by weight
Of Ni ₃ B in a dispersed state was formed.

4] Ni-B Plating Bath The Ni-B plating baths for forming the above-mentioned four kinds of Ni plating films are as follows, and the weight% of Ni ₃ B was adjusted by adjusting the pH. . _{NiSO 4 · 6H 2 O 0.1 mol} / L H 3 BO 3 0.1 mol / L (CH 3) 2 NH · BH 3 0.5 mol / L C 4 H 4 KNaO 6 · 4H 2 O 0.1 _{mol / L (NH 4) 2} SO 4 0.1 mol / L pH 6~10 bath temperature 60 ° C.

5] Test method The friction coefficient was measured by contacting the ring test piece 10 with the disk test piece 20 in the mission oil at room temperature and rotating the ring test piece, and using the load pattern as shown in FIG. 0.5 m /
s was measured by the method of measuring the change with time of the friction coefficient in 60 cycles. The wear amount was measured by a method of measuring the cross-sectional shape of the sliding surface before and after the friction coefficient measurement. The seizure peripheral speed was set to a load of 2350 N, and 0.5 m / s was set every 1 cycle equivalent time in FIG.
The peripheral speed was increased to 1.0 m / s, 1.5 m / s ... 0.5 m / s until seizure occurred.

6) Test Results (See FIGS. 10 to 16) The results of the friction coefficient measurement are as shown in FIG. 10, and the friction coefficient of Comparative Example 1 is a small value as a whole, but especially before the end. The coefficient of friction is extremely low. This is because wear progresses, the surface pressure decreases, and lubrication by oil becomes dominant. The Mo thermal spraying of Comparative Example 2 has a good initial friction coefficient, but is not preferable because the friction coefficient before the end is decreased (that is, the friction coefficient is decreased over time). Be of merits example, in those that do not contain Ni ₃ B (Ni ₃ B is 0 wt%) is not preferable because the coefficient of friction before the end is lower than the initial coefficient of friction. On the other hand, among the examples of the present invention, those containing 8 to 25% by weight of Ni ₃ B had an initial friction coefficient slightly inferior to Comparative Example 2, but a friction coefficient before the end was significantly larger than that in Comparative Example 2. Indicates the value. This is achieved by the particles of high hardness Ni ₃ B dispersed and precipitated in the coating substrate containing Ni as a main component.

The measurement results of the seizure peripheral speed are shown in FIGS.
2 is as shown in FIG. 2, and compared with Comparative Example 1 and Comparative Example 2,
Among the examples of the present invention, those containing 0 to 17% by weight of Ni ₃ B show equivalent or higher performance. 25% by weight of this example
In those containing Ni ₃ B, the seizure peripheral speed is reduced. It is considered that this is because the particles of high hardness Ni ₃ B are excessive, and biting with the ring test piece 10 on the mating side easily occurs.

The results of measuring the amount of wear are as shown in FIGS. As shown in FIGS. 15 and 16, in Comparative Example 1, the wear amount of the disk test piece 20 increases, while the wear amount of the ring test piece 10 on the other side decreases, but the durability cannot be secured in the end. . In Comparative Example 2, the amount of wear of the disk test piece 20 is small, but the amount of wear of the ring test piece 10 on the other side is large to some extent.

As shown in FIGS. 13 and 14, among the examples of the present invention, those containing no Ni ₃ B do not have high hardness Ni ₃ B particles in the coating film, so that the wear amount of the disc test piece 20 is small. It is not preferable because it increases. 25% by weight of the example
For those containing Ni ₃ B, although the wear amount of the disc test piece 20 is minimized, the amount of high hardness Ni ₃ B particles is excessive and the wear amount of the ring test piece 10 on the other side significantly increases. The durability of the material cannot be ensured, so it is hard to say that it can withstand practical use. On the other hand, 8 to 17 of the example of the present proposal
In the case of containing Ni ₃ B by weight, the wear amount of the disc test piece 20 and the wear amount of the ring test piece 10 on the other side are small,
It is extremely preferable.

From the above experimental results, it is very preferable that the coating film base material containing Ni as the main component contains a predetermined weight ratio of Ni ₃ B from the viewpoint of the friction coefficient, the seizure peripheral speed, and the wear amount. However, if Ni ₃ B is less than 8% by weight, good performance is exhibited in terms of friction coefficient and seizure peripheral speed, but Ni ₃ B having a high hardness is too small and the amount of wear increases, which is not preferable. Moreover, as can be seen from FIG. 11 and FIG. 14, Ni ₃ B is intended for 20 wt.%, Since Ni ₃ B high hardness becomes excessive, often wear amount of seizure circumferential speed is lowered and the counterpart material Therefore, it is not preferable.

After all, as the wear resistant coating 6 formed on the surface of the sliding portion 4 of the synchronizer ring 1, 8 to 20% by weight of Ni ₃ B is dispersed in the coating base material containing Ni as a main component. Abrasion resistant coatings are most desirable.
In addition, the solid solution B is contained in the coating film base material containing Ni as a main component. According to the wear resistant coating, since it is a coating base material containing Ni as a main component, it has excellent seizure resistance, and due to the high hardness Ni ₃ B particles distributed in a dispersed state, it has excellent wear resistance, A high coefficient of friction is secured over a long period of use, and the seizure peripheral speed can be sufficiently increased to enhance the seizure resistance.

Another embodiment: see FIGS. 17 to 20. Ni is formed on the surface of the sliding portion 4 of the synchronizer ring 1.
In order to test various performances when a wear resistant coating containing a predetermined weight ratio of Ni ₃ P (nickel phosphide) in a dispersed state is formed in a coating base material mainly containing Two
On the sliding surface 21 of 0, a precipitation hardening type Ni plating film (thickness 30 μm), which is a solid solution of P, and is 0, 10, 24, 5
A coating containing 6,70% by weight of Ni ₃ P in a dispersed state was formed and tested in the same manner as in the above example.

However, Ni for forming the Ni plating film
-P plating bath is as follows. _{NiSO 4 · 6H 2 O 0.1 mol} / L NaH 2 PO 2 · H 2 O 0.2 mol / L Na 3 C 6 H 5 O 7 · 2H 2 O 0.2 mol / L (NH 4) 2 SO ₄ 0.5 mol / L pH 5-10 Bath temperature 80 ° C

Since the test piece and the test method are the same as those in the above-mentioned embodiment, the description thereof is omitted, and the results of the friction coefficient measurement, the wear amount measurement, and the seizure peripheral speed are shown in FIGS. And explain. Comparative Example 1
The comparative example 2 and the comparative example 2 are the same as those of the example. Regarding the friction coefficient, as shown in FIG. 17, when the Ni ₃ P content is 0% by weight, the friction coefficient before the end is decreased, that is, the friction coefficient is decreased with time, which is not preferable because it cannot withstand long-term use. .

[0028] For sticking circumferential speed, as shown in FIG. 18, by way Ni ₃ P is 0-56% by weight, although sufficient seizure peripheral speed is obtained, when the Ni ₃ P is 60 wt.%, Seizure It was found that the peripheral speed was lowered, that is, the seizure resistance was lowered, which was not preferable. Regarding the amount of wear, as shown in FIGS. 19 and 20, Ni ₃ P is 0% by weight.
However, the amount of wear is large because Ni ₃ P having high hardness does not exist, which is not preferable. When the Ni ₃ P content is 10 to 56% by weight, the wear amount of the disc test piece 20 is also 1
The wear amount of 0 is very small, and excellent characteristics are obtained. However, when Ni ₃ P exceeds 60% by weight, the wear amount of the disc test piece 20 is small, but the wear amount of the ring test piece 10 on the mating side is large because the Ni ₃ P having high hardness is excessive. Therefore, it cannot withstand long-term use and is not suitable for practical use.

From the above experimental results, it is very preferable that the coating film base material containing Ni as the main component contains a predetermined weight ratio of Ni ₃ P from the viewpoint of the friction coefficient, the seizure peripheral speed, and the wear amount. There, Ni ₃ P is intended less than 10% by weight, although the burn surface of the circumferential speed show good performance, high hardness of Ni ₃ P
Is too small, the coefficient of friction is low and tends to decrease over time, and the amount of wear increases, which is not preferable.
Moreover, as can be seen from FIGS. 18 and 20, intended Ni ₃ P is greater than 60 wt%, the Ni ₃ P of high hardness becomes excessive, and reduces the circumferential speed is lowered resistance seizure seizure This is not preferable because the amount of wear of the mating material increases.

After all, as the wear resistant coating 6 formed on the surface of the sliding portion 4 of the synchronizer ring 1, 10 to 60% by weight of Ni ₃ P is dispersed in the coating base material containing Ni as a main component. Abrasion resistant coatings are most desirable. Incidentally, the coating film base material containing Ni as a main component contains solid solution P. According to the wear resistant coating, since it is a coating base material containing Ni as a main component, it has excellent seizure resistance, and due to the high hardness Ni ₃ P particles distributed in a dispersed state, it has excellent wear resistance, A high coefficient of friction is secured over a long period of use, and the seizure peripheral speed can be sufficiently increased to enhance the seizure resistance.

Next, various modifications that partially modify the above embodiment will be described. 1] Although the wear resistant coating 6 is formed by plating in the above-mentioned embodiments and other embodiments, it is also possible to form substantially the same wear resistant coating by thermal spraying other than plating. in this case,
Create a powder of Ni ₃ B and Ni ₃ P by an atomizing method or the like, Ni ₃ B
Mixture of Ni powder and Ni powder, Ni ₃ P powder and N powder
A wear-resistant coating is formed by spraying a mixture of the powder of i.

Alternatively, in addition to the plating treatment, a substantially similar wear resistant coating may be formed by powder sintering. in this case,
Create a powder of Ni ₃ B and Ni ₃ P by an atomizing method or the like, Ni ₃ B
Mixture of Ni powder and Ni powder, Ni ₃ P powder and N powder
The abrasion resistant coating is formed by powder sintering a mixture of the powder of i. Or, when plating,
By plating the i-B plating bath with the Ni ₃ B fine powder dispersed and added, or by plating the Ni-P plating bath with the Ni ₃ P fine powder dispersed and added. An abrasion resistant coating may be formed.

2] On the surface of the sliding portion of the synchronizer ring, the groove pitch of the triangular groove may be made small at the portion having the high peripheral speed, and the groove pitch of the triangular groove may be made large at the portion having the low peripheral speed. . In this case, it is possible to increase the surface pressure of the portion where the oil film of the oil is easily formed and the friction is easily reduced, and to transmit the torque evenly. Alternatively, in the surface of the sliding portion of the synchronizer ring, Ni in a portion with a high peripheral speed is
_The amount of ₃ B and Ni ₃ P dispersed is reduced, and
The amount of Ni ₃ B or Ni ₃ P dispersed may be increased. In this case, Ni ₃ B
It is possible to prevent seizure due to excessive dispersion of Ni ₃ P and Ni.

3) In the above embodiment, the case where the present invention is applied to the synchronizer ring which is a wear resistant sliding member has been described as an example. However, in addition to the synchronizer ring, a wet multi-plate clutch for an automatic transmission for automobiles is used. The present invention can be similarly applied to a friction plate, and in addition, the present invention can be similarly applied to various high-friction wear-resistant sliding members of a brake device and a clutch device.

[Brief description of drawings]

FIG. 1 is a sectional view of a synchronizer ring according to an exemplary embodiment of the present invention.

FIG. 2 is an enlarged sectional view of a sliding portion of the synchronizer ring.

FIG. 3 is a plan view of a ring test piece.

FIG. 4 is a front view of a ring test piece.

FIG. 5 is a plan view of a disc test piece.

FIG. 6 is a front view of a disc test piece.

7 is a cross-sectional view taken along the line AA of FIG.

8 is an enlarged cross-sectional view taken along the line BB of FIG.

FIG. 9 is a load pattern characteristic diagram at the time of tests of friction coefficient measurement and wear amount measurement.

FIG. 10 is a graph showing the friction coefficient measurement results of the present example and the comparative example.

FIG. 11 is a graph showing the results of measurement of the seizure peripheral velocity in the example of the present invention.

FIG. 12 is a graph showing the results of measuring the seizure peripheral speed of a comparative example.

FIG. 13 is a graph showing the results of measuring the amount of wear of the disk test piece of the present example.

FIG. 14 is a graph showing the results of measuring the amount of wear of the ring test piece of the present example.

FIG. 15 is a graph showing the results of measuring the amount of wear of a disk test piece of a comparative example.

FIG. 16 is a graph showing the results of measuring the amount of wear of a ring test piece of a comparative example.

FIG. 17 is a graph showing the friction coefficient measurement results of the example of the present invention and the comparative example according to another example.

FIG. 18 is a graph showing the results of measuring the peripheral velocity of image sticking in the example of the present invention according to another example.

FIG. 19 is a graph showing the results of measuring the amount of wear of the disk test piece of the present example according to another example.

FIG. 20 is a graph showing the results of measuring the amount of wear of the ring test piece of the present example according to another example.

[Explanation of symbols]

 1 Synchronizer ring 4 Sliding part 6 Abrasion resistant coating

Claims (8)

[Claims] 1. A wear resistant coating comprising a coating base material containing Ni as a main component and a wear resistant coating containing a predetermined weight ratio of Ni ₃ B formed on the surface of the sliding portion of the sliding member. Sliding member. 2. A wear resistant coating comprising a coating base material containing Ni as a main component and containing 8 to 20% by weight of Ni ₃ B on the surface of the sliding portion of the sliding member. Wearable sliding member. 3. A wear-resistant coating comprising a coating base material containing Ni as a main component and a wear-resistant coating containing a predetermined weight ratio of Ni ₃ P on the surface of the sliding portion of the sliding member. Sliding member. 4. A wear-resistant coating comprising a coating substrate containing Ni as a main component and containing 10 to 60% by weight of Ni ₃ P on the surface of the sliding portion of the sliding member. Wearable sliding member. 5. The wear resistant sliding member according to claim 1, wherein the wear resistant film is a film formed by plating. 6. The wear resistant sliding member according to claim 1, wherein the wear resistant film is a film formed by thermal spraying. 7. The wear resistant sliding member according to claim 2 or 4, wherein the sliding member is a synchronizer ring of a transmission for an automobile. 8. The wear-resistant sliding member according to claim 7, wherein the base material of the sliding member is made of an alloy of Cu and Zn.