JPH0681953A - Fluororesin sliding member - Google Patents

Abstract

PURPOSE:To provide a fluororesin sliding member which is applicable to a part to be reguired durability and sliding ability. CONSTITUTION:A 70-90wt.% fluororesin, 5-30wt.% aramide fibers and 1-10wt.% either graphite or molybdenum disulfide are mixed to mold a fluororesin slide member 1. This constitution results improvement of wear resistance, a mechanical strength and prolonged service life.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fluororesin sliding member used in a portion such as a packing ring or a piston ring which is required to have durability and slidability.

[0002]

2. Description of the Related Art Conventionally, as a sliding member as described above,
For example, there is a sliding member in which a predetermined amount of a filler such as carbon fiber or glass fiber is mixed with a fluororesin serving as a base material.

[0003]

However, the sliding member obtained by mixing the fluororesin and the filler in a predetermined amount as described above has heat resistance due to the characteristics of the fluororesin constituting the member.
Although it has excellent chemical resistance, it has a large amount of wear resistance and deformation due to load.Therefore, a method for improving wear resistance and mechanical strength by mixing a specified amount of filler such as carbon fiber or glass fiber has been proposed. Although being researched and developed, it is difficult to make up for the drawbacks of sliding members with the current base materials and fillers.
There are problems that the amount of wear is large and the life is short.

In view of the above-mentioned problems, the present invention blends a predetermined amount of either graphite or molybdenum disulfide in addition to a fluororesin and an aramid fiber to form a fluororesin sliding member, thereby providing abrasion resistance and mechanical properties. Strength is improved,
It is an object of the present invention to provide a fluororesin sliding member that can extend its life.

[0005]

The present invention is characterized in that it is a fluororesin sliding member prepared by blending a predetermined amount of either graphite or molybdenum disulfide in addition to the fluororesin and aramid fiber.

[0006]

According to the present invention, since a predetermined amount of either graphite or molybdenum disulfide is compounded in addition to the fluororesin and the aramid fiber constituting the fluororesin sliding member, the sliding member of the conventional example is used. Wear resistance is improved to about 3 times to about 5 times, and good wear characteristics can be obtained. Moreover, the amount of wear is small even when used under low pressure and high speed conditions, wear resistance and mechanical strength are improved, the life can be extended, and sliding parts mounted on various equipment are replaced. The number of times is reduced and maintenance work is facilitated.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail below with reference to the drawings. The drawing shows a fluororesin sliding member used in a portion where durability and slidability are required. In FIG. 1, the fluororesin sliding member 1 is a fluororesin (Daikin Industries M- 12), aramid fiber (Japanese aramid Twaron pulp) and graphite (LONZA
A composition obtained by mixing a predetermined amount of a filler of KS-75) and molding it into an appropriate shape by a free baking molding method.

When the fluorine sliding member 1 is molded by the above-mentioned free baking molding method, 70 wt% to 90 wt% of a fluororesin (polytetrafluoroethylene) is blended, and aramid fiber (fiber thickness 12 μm, fiber length about 0). 6 mm to about 0.7 mm) and 5% to 30% by weight of graphite and 1% to 10% by weight of graphite, and uniformly mixed by a high-speed juicer mixer (not shown).
The material is mixed at an appropriate ratio and preformed by setting the pressure to 0 kgf / cm ² , the holding time to 3 minutes, the molding temperature to 25 ° C. After that, the firing temperature is set to 370 ° C., the molding time is set to 6.5 Hr, and the product is integrally molded into an appropriate shape and dimension.

FIG. 2 shows a thrust type friction and wear tester 2 used for a sliding test of the fluorine sliding member 1. This thrust type friction and wear tester 2 is on the upper surface side of a rotary table 3 which constitutes the same. After the fluororesin sliding member 1 is mounted and fixed on, the metal counterpart 4 is pressed against the upper surface of the fluororesin sliding member 1, and then the rotary table 3 is rotated at a high speed to pressurize with the counterpart 4. The heat generation temperature and the friction coefficient generated in the sliding portion of the mating member 4 are measured.

That is, when measuring the exothermic temperature, the thermocouple 5 is inserted at a position about 3 mm away from the sliding portion of the mating member 4, and the thermoelectromotive force generated at the connection point of the thermocouple 5 is converted into the exothermic temperature. Record with a pen recorder (not shown). In addition, when measuring the friction coefficient K, the fluororesin sliding member 1
The friction resistance during sliding is detected by a load cell (not shown), and the resistance value is recorded by a pen recorder.

As a comparative example of the above-mentioned fluororesin sliding member 1, for example, the test of the present invention in which graphite (5 wt%) and aramid fiber (12.5 wt%) are mixed with fluororesin (82.5 wt%) Piece A and fluororesin (75 wt%)
A test piece B of a conventional product prepared by mixing carbon powder (25 wt%) with the above is subjected to a sliding test under the same conditions by the thrust type friction wear tester 2. That is, set the test atmosphere to air,
After setting the test temperature to 25 degrees, the test surface pressure P to 3 kgf / cm ² , the test speed V to 100 cm / sec, and the PV value to 300 kgf / cm ² · cm / sec, Counterpart material 4 (S
45CH) is set to have a surface roughness of 0.8 s, a test time from the start of the test to the end of the test is set to 20 Hr, and the test pieces A and B are sequentially tested.

Table 1 below shows the results of testing each test piece under the above conditions.

[0013]

[Table 1]

When measuring the wear coefficient K described in Table 1, each of the test pieces A and B was tested before and after the test.
Is weighed with an analytical balance, the wear height W is obtained from the wear weight M by the following formula 1, and the wear coefficient K is further obtained by the following formula 1.

[0015]

[Equation 1]

As is clear from the above test results, there is no significant difference in the friction coefficient and wear coefficient of the test pieces A and B at the time of initial sliding 4 hours after the start of the test, At the time of steady sliding after 4 hours and 20 hours, the test piece A has a smaller friction coefficient and wear coefficient than the test piece B, and is proved to have excellent durability and wear resistance. It

As described above, since a predetermined amount of graphite is added to the fluororesin and the aramid fiber constituting the fluororesin sliding member 1, the abrasion resistance is about three times that of the conventional sliding member. Up to about 5 times, and good wear characteristics can be obtained. Moreover, the amount of wear is small even when used under low pressure and high speed conditions, wear resistance and mechanical strength are improved, the life can be extended, and sliding parts mounted on various equipment are replaced. The number of times is reduced and maintenance work is facilitated.

The present invention is not limited to the configuration of the above embodiment.

Although a predetermined amount of graphite is added to the fluororesin and the aramid fiber constituting the fluororesin sliding member 1 in the above embodiment, for example, molybdenum disulfide is added to the fluororesin and the aramid fiber. It may be blended in a fixed amount, and the same effect as that of the above-described embodiment can be obtained.

Further, the compounding amounts of the base material and the filler may be increased or decreased according to the use conditions.

[Brief description of drawings]

FIG. 1 is a perspective view showing a fluororesin sliding member.

FIG. 2 is a vertical cross-sectional side view showing a thrust type friction wear tester.

[Explanation of symbols]

 1 ... Fluororesin sliding member 2 ... Thrust type friction / wear tester 3 ... Rotating table 4 ... Counterpart material 5 ... Thermocouple

Claims (1)

[Claims] 1. A fluorine resin is blended in an amount of 70 wt% to 90 wt%,
A fluororesin sliding member formed by blending 5 wt% to 30 wt% of aramid fiber and 1 wt% to 10 wt% of either graphite or molybdenum disulfide.