JPH02138395A - Combination sliding member - Google Patents

Abstract

PURPOSE:To obtain the title material not requiring any lubricant, being lightweight and improved in abrasion resistance by forming one member from nylon 66 containing potassium titanate fiber and the other member from an aluminum alloy having an alumite layer. CONSTITUTION:Nylon-66 is molten and 10-40wt.% potassium titanate whisker of a diameter of 0.1-1.0mum and an average length of 2-50mum is added to the melt to obtain nylon-66 (A) containing potassium titanate fiber. Separately, an aluminum alloy which can form an alumite layer as an oxide film by anodization is processed on the anode side in an electrolytic bath such as sulfuric acid bath or an oxalic acid bath to obtain an aluminum alloy (B) having an alumite layer of a hardness Hv >=200. At least the sliding surface of one of two sliding members is formed from component A, and at least the sliding surface of the other is formed from component B.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a combination sliding member that can be used, for example, in a release bearing hub and retainer of an automobile clutch device.

(Prior Art) Among the sliding parts used in automobiles, there is a release bearing hub la and a retainer 2 as shown in FIG. 4, which are made of resin on one side and light metal on the other and slide against each other. When the clutch pedal is depressed, the clutch release bearing 1 slides on the outer circumferential surface of the cylindrical retainer 2 toward the clutch plate in six directions to disengage the clutch.On the other hand, when the clutch pedal is returned, the clutch release bearing 1
slide toward the engine in direction B and connect the clutch.

In the past, release bearing hubs and retainers were
Wear-resistant metals have been used as materials for both, and sliding properties have been maintained by loading lubricants such as grease. However, because it is not easy to replace deteriorated grease or replenish new lubricating oil, and there is a demand for lighter cars, recently 66-nylon is being used for bearing hubs and aluminum alloy is being used for retainers. It is becoming. These materials are lightweight and 66
- Since nylon is highly self-lubricating, no lubricant is required on its sliding surfaces.

<Problems to be Solved by the Invention> However, the 66-nylon bearing hub and the aluminum alloy retainer that slide against each other do not have sufficient durability, and there is a problem in that the bearing hub and the retainer wear out. As this wear increases, the clearance between these sliding members increases, resulting in an increase in pedal depression force due to "heavyness" and a tendency for clutch disconnection failure to occur.

The present invention was made with the aim of solving problems caused by the materials of sliding members, as seen in the bearing hub and retainer mentioned above. It is an object of the present invention to provide a combination sliding member that does not require any additives and has further improved wear resistance.

(Means for Solving the Problems) The combined sliding member of the present invention capable of solving the above problems is composed of two members that slide against each other, and at least the sliding surface of one member is made of potassium titanate fibers of 10%. ~40wt%
66-nylon, and at least the sliding surface of the other member is an aluminum alloy having an alumite layer or an aluminum alloy having a Ni-2 to L3 wt% P alloy plating layer with a hardness of Hv600 or more. .

The combined sliding member of the present invention is preferably, for example, a dual-tube moving member that is conventionally often combined with a resin member and a light alloy member, particularly a clutch release bearing hub and a retainer.

One member having a sliding surface of 66-nylon containing 10 to 40 wt% of potassium titanate fibers may be made of such a composite material in its entirety, or even if only the sliding surface of the member is made of a composite material. good. For example, the member is made of whisker-like potassium titanate (N20) as a filler in a nylon melt.
-6T, i02 needle-like crystal material) can be mixed therein and manufactured by a thermoplastic resin molding method. The acicular crystal substance has a diameter of about 0.1 to 10 μm and an average length of 2 to 10 μm.
It may be about 50 μm. The reason why the content of potassium titanate fiber must be 10 to 40 wt% is 1.
If it is less than 0wt%, the effect of improving wear resistance will not appear, and if it is less than 40w
This is because if it exceeds t%, the amount of 66-nylon becomes relatively small, the strength of the member decreases, and the wear of the partner member increases rapidly due to the aggressiveness of the potassium titanate fibers.

Next, the other member, i.e., a small alumite layer on the sliding surface or a hardness of Hv 600 or more Ni-2 to 13
An aluminum alloy having a wt% P alloy plating layer will be described.

First, an aluminum alloy having an alumite layer is an aluminum alloy that can form an alumite layer (oxide film) by anodizing treatment (alumite treatment) according to a conventional method.
It is obtained by treatment on the anode side using an electrolytic bath such as a sulfuric acid bath, an oxalic acid bath, or a mixed bath thereof. The hardness of this alumite layer should just be Hv200 or more. If the temperature is lower than that, wear of the alumite layer increases.

In addition, an aluminum alloy having a Ni-2 to 13 wt% P alloy plating layer with a hardness of Hv600 or more is Ni:P=9
It is obtained by treating an aluminum alloy with a plating solution having a ratio of 8 to 87:2 to 13 according to a conventional method (electroless chemical plating or electrolytic deposition method), and then heat-treating it. The reason why the amount of P in the N1-P alloy in the plating layer was set to 2 to 13 wt% is because if it is less than 2 wt%, sufficient hardness cannot be obtained even if heat treatment is performed, and the amount of wear of the plating layer increases. This is because if the flea exceeds that level, even if hardness is obtained, the toughness of the plating layer decreases, making it easy for the plating layer to peel off.

<Example> Examples of the combined sliding member of the present invention will be described below while comparing with comparative examples, but the present invention is not limited thereby.

Example 1 As one member, 7 parts by weight of 6-Ro-1 nylon powder and 3 parts by weight of whisker-like potassium titanate were mixed, and the mixed melt was extruded to form a material having a size of 30 m.
A flat test piece measuring 30 mm x 5 mm was manufactured.

As the other member, aluminum alloy (JIS ADC
l2), outer diameter 25.4 mm, inner diameter 20 mm, length 1
A 6 mm cylindrical piece was prepared, and the outer surface of the cylinder was anodized in a sulfuric acid bath to produce a cylindrical test piece having an oxide film (alumite layer) with a thickness of 10 μm and a hardness of Hv300.

The cylindrical test piece and the flat plate test piece were combined and subjected to the following wear test.

Example 2 Instead of anodizing the outer surface of the cylindrical piece, Ni-8
A combination test piece consisting of a flat plate test piece and a cylindrical test piece was created in the same manner as in Example 1, except that wt%P alloy plating treatment was applied and heat treatment (350°C x 1 hr) was applied to make the hardness Hv900. It was subjected to the following abrasion test.

In addition, the plating treatment was performed by immersing the nickel sulfate in a plating bath containing appropriate amounts of pentahypophosphite, alkyl hydroxycarboxylic acid (complexing agent), a stabilizer, and a pH adjuster at a bath temperature of 90 to 95°C for about 40 minutes. A Ni-8wt%P alloy plating layer with a thickness of 206 m was formed.

Comparative Examples 1 to 9 66-nylon or 66-nylon with 30 wt% of glass fiber, carbon fiber, or potassium titanate fiber, respectively
Various flat test specimens were made using the additives. Also,
A cylindrical specimen made of aluminum alloy (JIS ADCl, 2) and further anodized,
and Nf-8wt%P alloy plating treatment (no heat treatment,
A cylindrical test piece with a plating layer hardness of Hv400) was also produced.

The various flat plate test pieces and cylindrical test pieces produced here were combined in various ways and combined test pieces were made by sliding them on each other (Comparative Examples 1 to 3).
9), it was subjected to the abrasion test described below.

The materials of the combination test pieces of Comparative Examples 1 to 9 are shown in Table 1 together with those of Examples 1 and 2 for easy understanding.

Table 1 Abrasion Test The combination test pieces of Example 1.2 and Comparative Examples 1 to 9 were set in order in an abrasion tester, and a flat plate test piece of 30 mm x 30
Contact the a++n surface with the end surface of the cylindrical test piece, and apply a load of 50K.
A wear test was conducted by rotating a flat plate specimen for 60 minutes at a rotation speed of 17 rpm.

The surface roughness of all flat test pieces was 1.5μRz,
On the other hand, the surface roughness of the cylindrical test pieces was 0.8 μRz for Comparative Examples 1 to 7 and Example 1, and 0.8 μRz for Comparative Examples 8.9 and Example 2.
The value is 1.0μR7.

The results of this wear test are shown in FIG. In the figure, the upper half represents the wear amount (wear scar depth) of the flat plate test piece, and the lower half represents the wear amount (wear weight) of the cylindrical test piece.

As can be seen from Figure 1), for the flat test specimens, those filled with reinforcing fibers are better than those not filled with reinforcing fibers (A, E).
) The amount of wear is smaller than that of Also, among the fibers, flat plate test pieces using potassium titanate fibers (D, H, D'
, J, K), the amount of wear is smaller.

On the other hand, when comparing the cylindrical test pieces with and without alumite treatment, those with alumite treatment (EH) have a smaller amount of wear. Moreover, among the alumite-treated cylindrical test pieces, the amount of wear was large when reinforcing fibers were used as the mating material. However, potassium titanate fiber (H)
The cylindrical test piece showed a small amount of wear and was good, probably because it did not have strong adversity like glass fiber or carbon fiber (F, G).

Also, when comparing the presence or absence of a plating layer, the one without (D')
It can be seen that the materials (J, K) are better than the materials (J, K), and the material (K) that has been heat-treated to increase its hardness is better.

As mentioned above, regarding wear resistance, the combination (H) of the 66-nylon member containing 30 wt% of potassium titanate and the anodized aluminum alloy member of Example 1 was followed by the 66-nylon member containing 30 wt% of potassium titanate of Example 2. Combination of nylon parts and plated/heat-treated aluminum alloy parts (
K) showed particularly excellent results.

Seizure test Each combination of Example 1.2 and Comparative Examples 1 to 9 above Combination H
It was confirmed that the anti-seizure property was particularly excellent.

Reference Example 1 Regarding combination H, in order to investigate the optimal loading amount of potassium titanate fibers into 66-nylon, N as shown in Table 3 below was used.
Combination test pieces of 011 to G were manufactured and subjected to the same wear test and seizure test as above. The surface roughness of each test piece and the thickness and hardness of the alumite layer of the cylindrical test piece were also the same as the previous test.

Table 3 The wear test results are shown in FIG. The amount of wear on the flat plate specimen is
The filling amount of potassium titanate fibers is 10 to 40 wt%, which is small and good. Below 10wt%, the amount of wear increases,
Moreover, if it exceeds 40 wt%, the strength decreases, resulting in insufficient wear resistance. On the other hand, the wear amount of the circular test piece is small up to 40 wt% of potassium titanate as the mating material, and begins to increase when it exceeds 40 wt%. From the above, it can be seen that when the filling amount of potassium titanate fibers is 10 to 40 wt%, the amount of wear is small (good) in both the flat plate and cylindrical test pieces.

In the seizure test, results were obtained that were proportional to the wear amount of the flat test piece shown in Figure 2, and the potassium titanate fibers
It was found that the seizure load was high at 0 wt%, and the seizure resistance was excellent.

Reference Example 2 In order to clarify the optimal hardness of the N L-8%P plating layer, wear tests and seizure tests were conducted using several types of cylindrical test pieces whose hardness was changed by changing the heat treatment temperature. I did it. Table 4 shows the combinations of test pieces.

Table 3 The test method and surface roughness of the test piece are the same as in the above test. The wear test results are shown in Figure 3.

The wear amount of the flat plate test piece is N i -8%P of the cylindrical test piece.
The hardness of the plating layer tends to increase slightly, but the amount of increase is small and the effect is small.On the other hand, the amount of wear on the cylindrical test piece is due to the hardness of the Ni-8wt%P alloy plating layer. is small (becomes) at Hv600 or higher. In other words,
It can be seen that if the hardness of the Ni-8wt%P alloy plating layer is Hv600 or more, the wear amount is small and good for both the flat plate and cylindrical test pieces.

Seizure tests were also conducted on the combinations of test pieces shown in Table 4, but as in the case of the wear test, Ni-8wt%P
It can be seen that if the hardness of the alloy plating layer is Hv600 or more, it exhibits excellent seizure resistance.

Example 3.4 and Comparative Examples 1O to 14 Comparative Example 1O511, 12, 13 and 14 and Example 3
and 4, the release bearing hub l shown in FIG.
a and retainer 2 are A, E, and F shown in Table 1, respectively.
, I)' and J and H and K flat plate test pieces (hub side)
It was manufactured using the same material combination as that of the cylindrical test piece (retainer side). The inner diameter of the resin hub is 33 ma+, and the clearance between the hub and the retainer is 100 gm. For each combination, bench stroke durability test (rotation speed 2000r
pm, stroke amount 8, On+111. After 106 strokes), the state of damage was compared. The results are shown in Table 5.

Table 5 As can be seen from the table, combination A, which can be called a conventional example, suffers the most wear, and if the damage progresses further, clutch disengagement will occur. It can be seen that the combination of H and the combination of K according to the present invention are significantly superior to the others in terms of the amount of wear on the pub and retainer and the increase in pedal effort.

<Effects of the Invention> As is clear from the above description, the combined sliding member of the present invention has excellent wear resistance and seizure resistance, even though it is a lightweight sliding member that can be used without lubricating oil. shows.

Therefore, for example, if the relay bearing hub and retainer of an automobile clutch device are constructed with the sliding member of the present invention,
Failures due to wear and increases in clutch pedal depression force are significantly reduced, making it possible to improve the safety and reliability of automobiles.

[Brief explanation of the drawing]

Fig. 1 is a diagram showing the results of a wear test of a combined sliding member according to an example of the present invention in comparison with that of a comparative example, and Fig. 2 is a diagram showing the relationship between the filling amount of potassium titanate fibers and the amount of wear in one test example. Figure 3 is a diagram showing the relationship between the hardness of the N1-P plating layer and the amount of wear in other test examples. Figure 4 is a sectional view showing the release bearing slidably attached to the retainer of the clutch device. It is. In the diagram: l...Clutch release bearing la...Release bearing hub 2...retainer Patent applicant Toyota Motor Corporation representative Patent attorney Yumi Sakai (2 idiots) 1st cause 2nd figure Flat plate test armpit Amount of potassium titanate fiber filling in a piece (wt%)
Figure 3

Claims (1)

[Claims] (1) Two members that slide against each other, and at least the sliding surface of one member has potassium titanate fibers of 10 to 10%
66-nylon containing 40 wt%, and at least the sliding surface of the other member is an aluminum alloy having an alumite layer. (2) Two members that slide against each other, and at least the sliding surface of one member contains 10 to 40 wt% of potassium titanate fibers.
66-nylon, and at least the sliding surface of the other member is an aluminum alloy having a Ni-2 to 13 wt % P alloy plating layer having a hardness of Hv600 or more.