JPH02219894A - Sliding member - Google Patents

Abstract

PURPOSE:To prevent a stick-slip phenomenon and to improve anti-seizing property by performing a carburizing-hardening treatment and a ryubrite treatment on one of the sliding faces of two iron members sliding against each other and forming a specified plating layer on another sliding face. CONSTITUTION:Carburizing-hardening treatment is performed on one of the sliding faces of two iron members sliding against each other and an Ni -2-13wt.% P plating layer wherein 15-35vol.% polytetrafluoroethylene with a particle diameter of 0.2-0.6mum is dispersed is formed on another sliding face and, if necessary, heat-treated to bring the hardness of a plated layer to Hv450 or higher.

Description

[Detailed description of the invention] (Industrial application field) The present invention relates to a combination of members that slide against each other.

(Conventional Techniques'IJ5) Various treatments have been proposed to improve the friction and wear characteristics of sliding members. For example, in a sliding member in a differential device, a carburized steel member is used as the gear side member, and the mating material (thrust washer) is manufactured using the tuftride method or gas nitrocarburizing method. Those that have been nitrided by a method such as the above are used.

(Problem to be Solved by the Invention) However, in sliding members, stick-slip phenomena that cause brake squeal, clutch chatter, etc. caused by microscopic adhesion between friction surfaces and slippage are a problem. Sometimes. In particular, in the gears and thrust washers of the above-mentioned differential device, when the operating environment such as lubrication conditions becomes severe, an oil film breaks down between these parts, resulting in problems such as stick-slip phenomenon and abnormal noise. becomes. Furthermore, such a sliding member also has the problem of being prone to seizure.

Therefore, it is an object of the present invention to provide a sliding member that prevents the stick-slip phenomenon that causes abnormal noise and has excellent seizure resistance.

(Means for Solving the Problems) In order to achieve the above object, the sliding member of the present invention is two iron-based members that slide against each other, and the sliding surface of the first member is immersed. Ni-2, which has been subjected to charcoal quenching treatment and lubrite treatment, and has 15 to 35% by volume of polytetrafluoroethylene (PTFE) dispersed on the sliding surface of the second member.
It is characterized in that a P plating layer of ~13% by weight is formed.

Preferably, after forming the plating layer on the second member,
By performing heat treatment, the Ni! of the plating layer is removed. Crystals of N1zP are precipitated by changing P, and the hardness of the plating layer is set to Hv450 or more.

If the amount of MFE dispersed is less than 15% by volume, the stick-slip phenomenon will not be sufficiently prevented, and the anti-seizure property will not be sufficient. On the other hand, if it exceeds 35% by volume, the wear resistance of the plating layer will deteriorate. Significantly reduced, 15-35% by volume
It is preferable that

The particle size of PTFE is preferably 0.2 to 0.6 μm.

If the P content in the plating layer is less than 2% by weight, sufficient hardness will not be obtained even after heat treatment, and the wear resistance of the plating layer will be poor (on the contrary, if it exceeds 13% by weight, the plating layer will deteriorate). 2 to 1 because the toughness decreases and peeling of the plating layer becomes more likely to occur.
The content is preferably 3% by weight.

The hardness of the plating layer is determined by each of the above factors from the viewpoint of wear resistance and seizure resistance, that is, PTF! It is preferable to set it to 11v450 or more by combining the amount of E dispersion, the amount of P, and the heat treatment conditions.

(Function) In the sliding member of the present invention, the sliding surface of the first member is carburized and the lubrite treatment is applied, and the sliding surface of the second member is formed with a PTFE dispersion plating layer. Stick-slip phenomenon due to sliding is less likely to occur. This is because the stick-slip phenomenon tends to occur when the coefficient of friction decreases as the sliding speed increases, but in sliding members treated as described above, the coefficient of friction increases as the sliding speed increases. This is thought to be due to the fact that Furthermore, the sliding member of the present invention is also excellent in seizure resistance.

(Example) Hereinafter, the present invention will be explained in more detail with reference to Examples.

Example 1: A steel (JIS standard: 5PCC) flat plate with a length of 70I11[l x width of 15aua x thickness of 10mu+] was prepared with a grain size of 0.
2-0.3 μm PTFE, nickel nitrate, sodium hypophosphite, alkylhydroxycarboxylic acid (complexing agent),
Alkyl dicarboxylic acid (reaction accelerator), stabilizer and pH
PTFE! Approximately 15 μm thick Ni-8% P alloy plating layer in which 25% by volume of
It was formed with a thickness of . Thereafter, by heat treatment at 300"C x 1 hour, the hardness of the alloy plating layer was reduced to Hv5.
It was set at 50. In this way, a flat plate test piece was created.

The test surface (sliding surface) of the flat test piece is a 70×15 square surface.

On the other hand, a ball test piece was prepared by subjecting a steel (JIS: SCM415H) 5/32-inch ball to carburizing and quenching treatment and lubrite treatment. The hardness of the ball test piece after carburizing and quenching was [1v750].

Comparative Example 1: A flat plate and a ball having the same material and the same dimensions as in Example 1 were used, the ball was carburized and quenched, and the flat plate was subjected to the same treatment as in Example 1 to obtain a ball test piece and a flat plate. A test piece was prepared. The hardness of the ball test piece achieved by carburizing and quenching is H-Schiff 50.

Comparative Example 2: Using flat plates and balls of the same material and dimensions as in Example 1 above, the balls were carburized and quenched in the same manner as in Comparative Example 1, and the flat plates were subjected to tuftride treatment to obtain ball test pieces and balls. A flat plate test piece was prepared. In addition, the hardness of the flat plate test piece achieved by the Tuftride treatment is II Shiloh 50.

Comparative Example 3: A flat plate and ball of the same material and same dimensions as in Example 1 were used, the ball was subjected to carburizing and quenching and lubrite treatment as in Example 1, and the flat plate was treated with tuftride as in Comparative Example 2. By performing the treatment, a ball test piece and a flat plate test piece were created.

Comparative Example 4= A flat plate and ball of the same material and size as in Example 1 were used, the ball was subjected to the same carburizing and quenching and lubrite treatment as in Example 1, and the plating solution in the planar plate contained PTFE. A ball test piece and a flat plate test piece were prepared by performing the same treatment as in Example 1 except that there was no test piece.

Test Example 1: Friction Test Each combination of the flat plate test piece and ball test piece prepared in Example 1 and Comparative Examples 1 to 4 above was sequentially set in a Bowden friction tester and heated to about 80''C for a flat plate test. Apply lubricating oil (TF; trade name: Dexron I[J) to the test surface of the piece.
After coating, a friction test was conducted by bringing a ball test piece into contact and sliding one side of the flat plate test back and forth at a sliding speed of 0.06 to 2 values/sec while applying a load of 2 kg.

In addition, the surface roughness of the flat plate test piece is 2 to 3 μmRZ.

The relationship between the friction coefficient μ and the sliding speed V (μ-■ characteristic) determined by the test is shown in the graph of FIG.

As is clear from FIG. 1, the test piece of Example 1 has v=
In the case of 0, the friction coefficient is the lowest compared to the test pieces of Comparative Examples 1 to 4, and the μ-■ characteristics show an upward trend in which the friction coefficient increases as the speed increases.

On the other hand, in all other comparative examples, the μ-V characteristics are downward sloping. - It is known that the stick-slip phenomenon occurs when the coefficient of friction is high and the μ-■ characteristics are downward sloping. From this, it can be seen that the material combination of Example 1 can effectively prevent the generation of abnormal noise due to the stick-slip phenomenon.

Example 2 30mm X made of steel cloth (J Is: 5PCC)
A 30 mm x 10 mm thick flat plate was made of Ni in which 25% by volume of E'TFIE was dispersed by the same method as in Example 1.
A -8% P alloy plating layer was formed with a thickness of about 15 μm.

Thereafter, the hardness of the alloy plating layer was set to !I v 550 by performing heat treatment for 300''C x 1 hour.

The 30 x 30 m surface of the obtained flat plate specimen was used as the test surface (
(sliding surface).

A cylinder with an outer diameter of 25.4 m x an inner diameter of 20 m x a length of 10 irises was subjected to carburizing and quenching treatment and lubrite treatment to create a cylindrical test piece.

Comparative Examples 5 to 8 The same flat plates and cylinders as in Example 2 were used for the flat plates and balls in Comparative Examples 1 to 4, corresponding to the combination symbols B, C, D, and E shown in Table 2 below. The treatments were carried out to produce flat plate test pieces and cylindrical test pieces of Comparative Examples 5 to 8.

Test Example 2: Seizure test The flat plate test pieces and cylindrical test pieces of Example 2 and Comparative Examples 5 to 8 were combined and set in a seize test machine, and the flat plate test pieces (3
0aa A seizure test was conducted by increasing the pressing load in stages until the seizure occurred and measuring the load by ++jJ degrees.

The results are shown in Table 2.

As is clear from Table 2, the test piece of Example 2 has better seizure resistance than those of each comparative example.

Test Example 3: Wear Test A wear test was conducted using the same test machine as used in the seizure test in Test Example 2 above, and using the same test pieces as in Example 2 and Comparative Examples 5 to 87 above. First, lubricant (
ATF: While dropping ATF (trade name) "Dexron 11L" at 0.8 cc/min, the same test piece was rotated at a rotational speed of 500 rpm, and a cylindrical test piece was pressed against it at 200 kgF.
A wear test was conducted for 0 minutes. The depth of the sliding marks (wear depth) on one side of the flat plate test was measured. The results are shown in Table 3.

Table 3 From Table 3, it can be seen that the wear depth of the test piece according to Example 2 is shallower than that of Comparative Example 5.6.7. Comparative example 8 is
Although the wear depth of the flat plate test piece was shallower than that of Example 2, the wear of the cylindrical test piece, which was the mating member, was large, so Example 2 had the best wear resistance overall.

Test Example 4: P in N1-BP+PTFE layer plated on flat test piece
TF [! The amount is 10% by volume, 15% by volume, 25% by volume,
Example 1 above except that the settings were 35% by volume and 40% by volume.
Alternatively, test pieces prepared in the same manner as in Example 2 were tested for μmV characteristics, wear coefficient (μ level), wear depth, and seizure resistance.

The results are shown in Table 4.

As shown in Table 4, the amount of PTFE is preferably 15 to 35% by volume.

Example 3 FIG. 2 is a sectional view showing the differential device 1. FIG.

In the differential device 1, the side gear 2 and pinion gear 3, which correspond to the first member of the present invention, are made of steel (JIS: SC1'1415) 1), and the surface is carburized and quenched, and then subjected to a lubrite treatment. The thrust washer 5 and the spherical washer 6 were made of steel plate (JIs: 5PCC) as the second member.
Made of Ni-8P with PTFE dispersed on the surface (25% by volume)
An alloy plating layer 01v550) was formed. In addition, in the figure, 3 indicates a pinion gear, 4 indicates a pinion shaft, and 7 indicates a spline.

Comparative Examples 9 to 11; In the above Comparative Examples, the above side gear 2 and pinion gear 3 were manufactured using materials corresponding to the ball test pieces with combination symbols B and C1 Hei, and the materials corresponded to the flat plate test pieces with combination symbols B and C1 Mi. A thrust washer 5 and a spherical washer 6 were manufactured using the same materials, and a differential device manufactured by combining these parts was assembled into a vehicle and a turning test was conducted. Table 5 shows the occurrence of abnormal noise due to the stick-slip phenomenon measured in this test.
Shown below.

In Comparative Example 9.10.11 (Combinations B, C, and E), abnormal noise due to stick-slip was confirmed from the beginning, whereas in the combination of Example 3, the noise was observed not only at the beginning but also after the 11,000k running test. There was no abnormal noise caused by stick-slip, and the results were good.

(Effects of the Invention) 4. In the sliding member of the present invention, since the stick-slip phenomenon is effectively prevented, brake squeal, clutch chatter, etc. are prevented. In addition, the seizure resistance is approximately 1.
75 times more expensive. Therefore, the quality and durability of products manufactured using the sliding member of the present invention are significantly improved.

[Brief explanation of the drawing]

Fig. 1 is a graph showing μm characteristics of sliding members manufactured in Examples and Comparative Examples of the present invention, and Fig. 2 is a cross section showing a differential device to which a sliding member of an embodiment of the present invention is applied. It is a diagram. ■...Differential device 2...Side gear 3...Pinion gear 5
... Thrust washer 6 ... Spherical washer 1st, all 1, v (mrn/sec)

Claims (1)

[Claims] Two iron-based members that slide against each other, the sliding surface of the first member is carburized and quenched and the sliding surface of the second member is coated with 15 to 35% by volume. A sliding member comprising a Ni-2 to 13% by weight P plating layer in which polytetrafluoroethylene is dispersed.