JPH07145248A - Sliding member for vibration absorption - Google Patents

Abstract

PURPOSE:To obtain a vibration-absorbing sliding member useful for a mast strip for fork lift, having low frictional properties and vibration absorption characteristics and excellent sound-damping qualities, comprising a polytetrafluoroethylene resin and a block polyester ester copolymer. CONSTITUTION:This sliding member comprises a block polyester ester copolymer consisting of (A) preferably 1-20wt.% of a polytetrafluoroethylene resin having preferably 25mum average particle diameter and the rest substantially of (B) a polybutylene terephthalate as a main hard segment and a polytetramethylene oxide as a soft segment. The sliding member comprises preferably 0.1-10wt.% of effective powder (preferably oxybenzoyl polyester or polyimide) besides the composition.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sliding member which is excellent in low frictional property and vibration absorption property and is excellent in sound deadening effect.
This sliding member is particularly useful as a sliding member for a forklift mast strip.

[0002]

2. Description of the Related Art Mast strips for forklift trucks are
It is used as a spacer between the mast guides provided on the claw side and the main body side of the forklift, and absorbs vibration. Also, when the claw is moved up and down, it slides while absorbing the vibration. Therefore, vibration absorbing characteristics and sliding characteristics are required as the characteristics of such a forklift mast strip. As a conventional mast strip material for a forklift, a lead bronze-based sintered product or the like is used.

[0003]

[Problems to be Solved by the Invention] Lead bronze-based sintered products are
Since the vibration absorption property is poor, there is a problem that squeaking noise peculiar to metal is generated during sliding, and a high friction coefficient causes stick-slip, which is not sufficiently satisfactory. In addition, the processing cost is high, leading to higher costs. The present invention focuses on the excellent elastic properties of the block polyether ester copolymer, that is, by utilizing the excellent vibration absorption characteristics, to provide a vibration absorbing sliding member having excellent friction and wear characteristics, and , For the purpose of cost reduction.

[0004]

Means for Solving the Problems The present invention is to solve the above-mentioned object, and the gist thereof is (1)
Vibration absorbing sliding member made of polytetrafluoroethylene resin, block polyether ester copolymer,
(2) 1 to 20% by weight of polytetrafluoroethylene resin, the rest being a sliding member for vibration absorption consisting essentially of a block polyether ester copolymer, (3) 0.1 to 10% by weight of organic powder in addition to the above 2. % Of the vibration absorbing sliding member.

The present invention will be described in detail below. The block polyether ester copolymer used in the present invention is
Polybutylene terephthalate is the main hard segment and polytetramethylene oxide is the soft segment, and it is a thermoplastic resin that is excellent in elastic properties, mechanical strength, and oil and chemical resistance, and is an injection moldable resin. The block polyether ester copolymer is disclosed in JP-A-2-28.
It is manufactured by the method described in 3759 gazette and is commercially available.

The polytetrafluoroethylene resin (hereinafter referred to as PTFE) in the composition of the present invention preferably has an average particle size of 25 μm, and commercially available products include TLP-10F-manufactured by Mitsui DuPont Fluorochemicals.
1, TLP-10, MP1300, Lubron L-5, L-2 manufactured by Daikin Industries, KTL-500F manufactured by Kitamura, and the like are used. The content of PTFE is 1 to 20% by weight, more preferably 5 to 15% by weight. If the content is less than 1%, the improvement in the improvement of sliding characteristics and non-seizure characteristics becomes small. On the other hand, if it exceeds 20% by weight, the resin strength becomes weak and the abrasion resistance is deteriorated.

In the present invention, the wear resistance and the load resistance can be further improved by adding 0.1 to 10% by weight of the organic powder. As the organic powder, oxybenzoyl polyester, polyimide, polyether ether ketone, polyamide imide, and aromatic polyamide are preferable, and if less than 0.1% by weight, the effect of addition is not obtained, and if more than 10% by weight, vibration absorption characteristics deteriorate. . Further, a coloring agent such as carbon black may be used in combination unless the effect of the present invention is impaired.

[0008]

EXAMPLES The raw materials used for the product of the present invention and the comparative product are shown below. Block Polyether Ester Copolymer: Toray DuPont Hytrel 5557 PTFE: Mitsui DuPont Fluorochemical TLP
-10 Organic Powder (Oxybenzoyl Polyester): Econoll E101S Lead Bronze: LBC3 manufactured by Sumitomo Chemical Co., Ltd. The raw materials (1) to (3) above were mixed in the proportions shown in Table 1 and dry blended with a Henschel mixer. After that, while melt-kneading with a 40 mm diameter extruder (extrusion temperature 240 ° C.),
An extrusion operation was performed to obtain a uniform blended pellet. Next, these pellets were molded using a normal injection molding machine at a cylinder temperature of 220 ° C to 250 ° C and a mold temperature of 40 to 70 ° C to obtain a product of the present invention. In addition, the raw material of (3) was compacted and sintered to obtain a comparative product.

Table 3 shows the results obtained by testing the friction characteristics and stick-slip of the materials obtained in the above-mentioned examples under the test conditions shown in Table 2 by the reciprocating sliding tester shown in FIG. In addition, Table 4 shows the results of tests for the presence or absence of squeaking noise in the actual vehicle test. As is clear from the test results of Tables 3 and 4, according to the present invention, it was possible to obtain a sliding member having a low friction coefficient, no stick-slip, and no vibration noise due to the vibration absorption characteristics of the material. .

[0010]

[Table 1]

[0011]

[Table 2]

[0012]

[Table 3]

[0013]

[Table 4]

[0014]

INDUSTRIAL APPLICABILITY The sliding member of the present invention has low friction characteristics, and has the advantage that squeaking noise does not occur during sliding and stick-slip does not occur due to the vibration absorption characteristics of the material, especially for forklifts. It is useful as a sliding member for mast strips. In addition, the sliding member of the present invention is a material that can be injection-molded and therefore has a low unit price and can meet the needs of the market.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a mast strip.

FIG. 2 is a schematic view of a reciprocal sliding tester.

[Explanation of symbols]

 1 Mast strip 2 Lift side guide 3 Lift body 4 Load receiving side guide 5 Sample (mast strip) 6 Test axis 7 Sample holder 8 Load cell 9 Hydraulic cylinder

Claims (3)

[Claims] 1. A vibration absorbing sliding member comprising a polytetrafluoroethylene resin and a block polyether ester copolymer. 2. Polytetrafluoroethylene resin 1-2
A vibration-absorbing sliding member, characterized in that 0% by weight and the balance substantially consisting of a block polyether ester copolymer. 3. A vibration-absorbing sliding member which contains 0.1 to 10% by weight of an organic powder in addition to the composition described in claim 2.