JPH11190345A - Multi-layered slide member and its manufacture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an excellent joint force with respect to a back plate and to exhibit an excellent friction and abrasion characteristic without a resin slide layer melt-flowing or peeling off from the back plate even though it is use even in a severe frictional condition. SOLUTION: This slide member is composed of a back plate 1 made of a steel pipe, an expand metal 2 made of copper alloy and integrally incorporated with the inner surface of the back plate 1, and a slide layer 3 made of a lubrication resin composition material, for covering the inner surface of the back plate 1 together with the expand metal 2. The composition material is composed of 5-20 wt.% of polyhexamethylene adipamide resin, 5 to 20 wt.% of tetrafluoroethylene resin, 3 to 10 wt.% of potassium titanate whisker, 3 to 10 wt.% of phosphate and the balance of polytetramethylene adipamide resin.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multi-layer sliding member and a method for producing the same. The present invention relates to a sliding member having a lubricating resin composition on its surface, especially for high load applications and dry friction conditions. The present invention relates to a multi-layer sliding member suitable for use below and a method for producing the same.

[0002]

2. Description of the Related Art Conventionally, as a thermoplastic resin sliding member for the purpose of improving abrasion resistance and load resistance, a multi-layer structure in which a thermoplastic resin is applied as a thin layer on a metal backing has been used. A sliding member is known. For example, a sliding member in which a porous metal sintered layer is formed on a steel sheet and the porous metal sintered layer is impregnated with a thermoplastic resin (Japanese Patent Publication No. 311-2)
No. 452), a metal wire mesh is filled with a thermoplastic resin and coated, and this is joined to a bearing base piece (Jikken 48).
Further, a sliding member in which an adhesive layer is formed on a steel plate and a thermoplastic resin is adhered to the adhesive layer may be used.

[0003] In the sliding member having the above-mentioned multi-layer structure, even if the thermoplastic resin is relatively soft, if the thermoplastic resin is applied as a thin layer on a back metal such as steel, the deformation of the resin itself may occur. Since settling does not occur, the wear resistance and load resistance of the sliding member are improved as a result. Further, the frictional heat generated on the sliding surface is easily transmitted to the backing metal through the thin resin layer and is radiated from the sliding member, so that the temperature rise can be suppressed low, and the above-described performance is further promoted. . Further, since the resin is hardly affected by expansion, contraction or aging, the dimensional stability of the sliding member is remarkably improved.

A sliding member disclosed in Japanese Patent Publication No. 31-2452 and a sliding member in which a synthetic resin is applied on a steel plate via an adhesive layer generally have a plate-like multilayer structure. After producing the body, it is wound with the resin layer inside, and used as a so-called wound bush. In the sliding member disclosed in Japanese Utility Model Publication No. 48-4411, a liner in which a metal wire mesh is filled with a synthetic resin is bonded to the inner peripheral surface of the cylindrical back metal to be used as a cylindrical sliding member. You.

[0005]

However, the above-described wound bush requires a bending process to be wound into a cylindrical shape, and thus has a problem in that the thickness of the steel plate constituting the back metal is limited. . Therefore, when a thick back metal is required, there is a manufacturing complexity that the winding bush has to be separately press-fitted into a thick cylindrical housing. On the other hand, the aforementioned Japanese Utility Model Publication No. 48-4411
In the case of using a cylindrical sliding member using the structure disclosed in Japanese Patent Application Laid-Open Publication No. H06-27138, the metal wire mesh filled and coated with a synthetic resin is bonded to the inner peripheral surface of the housing with an adhesive or the like. Therefore, there is a problem that use conditions are restricted.

[0006] In addition, in the above-mentioned wound bush, since a butt portion is formed in manufacturing, when a load point is applied to this portion, there is a possibility that the sliding layer may be damaged by the load point. Further, there is a problem that the resin layer melts and flows under severe friction conditions and peels off from the back metal.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and has as its object the purpose of obtaining a sufficient bonding force between the back metal and the resin sliding layer even under severe friction conditions. An object of the present invention is to provide a multilayer sliding member exhibiting excellent friction and wear characteristics without being peeled off or peeling off from a backing metal, and a method for producing the same.

[0008]

According to the present invention, the above object is achieved by a back metal made of a steel pipe, an expanded metal made of a copper alloy integrally joined to the inner peripheral surface of the back metal, and a back metal made of the expanded metal together with the expanded metal. A sliding layer of a lubricating resin composition covering the inner surface thereof, wherein the lubricating resin composition comprises a polyhexamethylene adipamide resin 5
~ 20% by weight, ethylene tetrafluoride resin 5 ~ 20% by weight,
Potassium titanate whisker 3-10% by weight, phosphate 3
This is achieved by a multi-layer sliding member composed of a polytetramethylene adipamide resin of 10 to 10% by weight.

Further, according to the present invention, the object is to provide a back metal made of a steel pipe, an expanded metal made of a copper alloy integrally joined to an inner peripheral surface of the back metal, and a cover of an inner surface of the back metal together with the expanded metal. A method for producing a multilayer sliding member comprising a lubricating resin composition and a sliding layer,
(A) pressing the expanded metal in its thickness direction to form a flat surface on the front side and the back side of each joint portion of the expanded metal; and (b) forming the flat surface along the inner peripheral surface of the back metal. Inserting an expanded metal, and pressing and holding the flat surfaces of the joints on the inner peripheral surface of the back metal by a springback force of the expanded metal;
(C) placing the back metal with the expanded metal pressed against the inner peripheral surface thereof in a heating furnace adjusted to an inert gas atmosphere, a reducing gas atmosphere or a vacuum atmosphere at a temperature of 800 to 1000 ° C. for 20 to 60 minutes; Each metal joint is diffusion bonded to the inner peripheral surface of the back metal to form a wedge-shaped engaging portion between each joint and the inner peripheral surface of the back metal. A step of obtaining a sliding member base in which the mesh of the expanded metal is continuous through a minute gap between the sliding member base and a surface; and (d) inserting a core inside the sliding member base, and inserting the core into an injection molding machine. After being set in the mold, 5-20% by weight of polyhexamethylene adipamide resin, 5-20% by weight of ethylene tetrafluoride resin, potassium titanate Whisker 3-10 weight Injection molding a lubricating resin composition comprising 3-10% by weight of a phosphate and a balance of polytetramethylene adipamide resin, and (e) injection molding of the lubricating resin composition. A step of filling the mesh of the expanded metal, the wedge-shaped engaging portions and the minute gaps, and covering the surface of the expanded metal to form a slip layer thereon;
This is also achieved by the method for manufacturing a multilayer sliding member comprising the steps of:

Further, in the above manufacturing method, in the step (b), a pipe made of stainless steel is inserted through a minute gap on the inner peripheral side of the inserted expanded metal, and in the step (c), The pipe may be removed after each joint of the expanded metal is diffusion bonded to the inner peripheral surface of the back metal while thermally expanding the pipe and the back metal.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of a multi-layer sliding member and a method of manufacturing the same according to the present invention will be described with reference to the drawings. 1 is an external perspective view showing a multilayer sliding member according to the present invention, FIG. 2 is a partially broken plan view showing a state where the multilayer sliding member shown in FIG. 1 is developed, and FIG. FIG. 3 is a sectional view taken along the arrow II in FIG. 2.

The multi-layer sliding member of the present invention is shown in FIGS.
As shown in FIG. 1, a back metal 1 made of a steel pipe, an expanded metal 2 made of a copper alloy integrally joined to an inner peripheral surface 11 of the back metal 1, and an inner peripheral surface 11 of the back metal 1 together with the expanded metal 2 are covered. And a slip layer 3 made of a lubricating resin composition. As shown in FIG. 3, the expanded metal 2 has a joining portion 21 of the mesh diffusion-bonded to the inner peripheral surface 11 of the back metal 1 to form a wedge-shaped engaging portion 22, and a mesh 23 of the expanded metal 2 is formed. Is the mesh 23
Between each side 24 and the inner peripheral surface 11 of the back metal 1
Are formed, and a mesh 23 of the expanded metal 2 is formed.
Are continuous via the minute gap 4. And, the slip layer 3 of the lubricating resin composition is a mesh 2 of the expanded metal 2.
3, filling the wedge-shaped engaging portion 22 and the minute gap 4,
It is formed so as to cover the surface of the expanded metal 2.

In the present invention, the steel pipe constituting the backing metal 1 is a steel pipe or a steel strip formed into a tube in addition to a steel pipe manufactured seamlessly using a material having a so-called round or square cross section.
It includes steel pipes manufactured by joining the joints by electric resistance welding, forging, arc welding, or the like.

The expanded metal 2 is cut linearly and continuously at a predetermined pitch with respect to the metal thin plate, and is provided with a phase difference for each row to perform a cutting process of a predetermined length and expand the cut. , A wire net-like metal sheet having a regular mesh line, such as a substantially rectangular shape. The expanded metal 2 reinforces the sliding layer 3 made of the lubricating resin composition and plays a role as a load supporting portion of the sliding member.

As the material of the expanded metal 2, alloys such as phosphor bronze, brass, beryllium copper, nickel silver, aluminum bronze and the like are used. Thickness of expanded metal 2 (thickness of original plate before expanded processing) is 0.1 to 1.5
mm, the step width is about 0.5 to 1.2 mm, the longitudinal diagonal length of the mesh 23 is about 1.0 to 12.0 mm,
The short diagonal length of the mesh 23 is about 1.0 to 10.0 mm. Such specific dimensions and variations in the shape of the mesh 23 can be variously adopted, but in the present invention, the opening area of one mesh 23 is 1 to 60 mm ² , and the opening ratio of all the meshes 23 is 30 to 70% expanded metal can be exemplified.

The expanded metal 2 is connected to each of the joints 2.
1, the back metal 1 is diffusion bonded to the inner peripheral surface 11 of the back metal 1.
A wedge-shaped engaging portion 22 is formed between the inner peripheral surface 11 and the inner peripheral surface 11;
Since the mesh 23 of the expanded metal 2 is continuous through the minute gap 4 formed between each side 24 of the mesh and the inner peripheral surface 11 of the back metal 1, the peel strength of the back metal 1 to the inner peripheral surface 11 is low. The bonding strength with the slip layer 3 made of a lubricating resin composition described later is increased.

Each joining portion 21 of the expanded metal 2 diffusion-bonded to the inner peripheral surface 11 of the back metal 1 preferably has a flat surface 25 at the tip. Expanded metal 2
When the flat surface 25 is formed on the joint portion 21 of the joint member, the load is evenly applied over the entire flat surface 25 of the joint portion 21 in sliding with the counterpart material, as compared with the case where a normal expanded metal having a sharp joint portion is used. Therefore, the slip layer 3 made of the lubricating resin composition is not broken. In addition, even if the sliding layer 3 is worn and the expanded metal 2 is directly slid with the mating material, the surface of the mating material is damaged by the joint 21 of the expanded metal 2 formed on the flat surface 25. I will not let you.

The lubricating resin composition for forming the slip layer 3 comprises a polytetramethylene adipamide resin as a main component,
It is made by mixing a predetermined amount of polyhexamethylene adipamide resin, ethylene tetrafluoride resin, potassium titanate whisker and phosphate.

Polytetramethylene adipamide resin (hereinafter, referred to as "nylon 46"), which is a main component of the lubricating resin composition, has excellent mechanical strength such as tensile strength, bending strength, impact strength, and heat resistance. Since it has excellent sliding characteristics, it is particularly suitable for use under severe friction conditions.

Nylons 4 and 6 have the advantages described above, but have the disadvantage that the melting point is as high as about 290 ° C. and the temperature range suitable for molding is narrow because thermal decomposition occurs at about 320 ° C. In general, in the evaluation of synthetic resins, moldability is important, and even if it has inherently excellent properties, it is not only impossible to economically manufacture a product if the range of molding conditions is narrow, but also that Good properties are not fully exhibited in the product. For example, when a product having a high softening temperature or melting point and a high melt viscosity is used to manufacture a product by an injection molding method, a high plasticizing temperature, a high injection pressure, a high mold temperature, and the like are required, which is a high cost. Not only causes, high plasticization temperature induces thermal decomposition of the resin, high injection pressure causes distortion in the product, and when violating such severe conditions, the appearance of sink marks, flow marks, etc. This causes a fatal drawback, and causes a significant decrease in mechanical strength.

In the present invention, a predetermined amount of polyhexamethylene adipamide resin (hereinafter referred to as "nylon 6
6 ") can solve the above-mentioned disadvantages of nylon 46. That is, the plasticization temperature during injection molding of nylon 46 alone can be reduced by blending nylon 66, and molding can be performed in a wide molding temperature range without causing thermal decomposition of the resin. Has the effect of significantly increasing elongation. The amount of nylon 66 is 5 to 20% by weight, preferably 10 to 15%.
% By weight is appropriate. If the compounding amount is less than 5% by weight, no effect is obtained in improving the moldability, and if the compounding amount exceeds 20% by weight, the heat resistance and mechanical strength of the nylon 46 described above are impaired.

Ethylene tetrafluoride resin (hereinafter "PTFE")
Is to provide lubricating properties to the slip layer made of the resin composition, and to enable the sliding member to be used under dry friction conditions. The compounding amount is suitably 7 to 25% by weight, preferably 10 to 20% by weight. Compounding amount is 7
When the amount is less than 25% by weight, the effect of imparting lubricity is not exhibited and the sliding member cannot be used under dry friction conditions, and when the amount exceeds 25% by weight, the mechanical strength is reduced. Becomes

The potassium titanate whisker improves the mechanical strength and heat resistance of the slip layer made of the resin composition, and has the effect of improving the wear resistance of the slip layer by being uniformly dispersed in the slip layer. Demonstrate. As the potassium titanate whisker, those having an average fiber diameter of 2 μm or less, an average fiber length of 5 to 100 μm, and an aspect ratio of 10 or more are preferably used. Although this potassium titanate whisker can be used alone, it may be used by previously containing it in the above-mentioned nylon 66, and the latter is preferred from the viewpoint of uniform dispersibility in the slip layer. And the compounding amount of potassium titanate whisker is 3 ~
15% by weight, especially 5 to 10% by weight, is suitable. If the compounding amount is less than 3% by weight, the above effect is not exhibited, and if the compounding amount exceeds 15% by weight, the ratio of exposure to the slip layer increases, resulting in a disadvantage that the partner material is damaged.

Phosphate itself is not a substance exhibiting self-lubricating properties such as graphite, for example. However, when phosphate is blended with the above-mentioned PTFE blended in the composition, P
Together with TFE, it is effective in improving the friction and wear characteristics of the sliding layer. By the combination of this phosphate and PTFE,
The reason why the friction and wear characteristics of the sliding layer are improved is not clear, but nylon and PTF are added to the surface of the mating material after the sliding friction test.
Considering that a lubricating film in which E and phosphate were combined was formed, it was inferred that the effect of the phosphate on the improvement of the friction and wear characteristics was due to the excellent film forming property of the lubricating film. You.

The phosphate used in the present invention includes tertiary phosphoric acid, secondary phosphoric acid, pyrophosphoric acid, phosphorous acid,
Examples thereof include metal salts such as metaphosphoric acid and mixtures thereof. Among these, metal salts of tertiary phosphoric acid, secondary phosphoric acid and pyrophosphoric acid are preferred. As the metal, an alkali metal and an alkaline earth metal are preferable, and lithium (Li), calcium (Ca), magnesium (Mg) and barium (Ba) are particularly preferable.

Specifically, lithium phosphate (Li ₃ P
O ₄ ), lithium hydrogen phosphate (Li ₂ HPO ₄ ), lithium pyrophosphate (Li ₄ P ₂ O ₇ ), tricalcium phosphate (Ca ₃ (PO ₄ ) ₂ ), calcium pyrophosphate (C
a ₂ P ₂ O ₇ ), calcium hydrogen phosphate (CaHP)
O ₄ ) is the most preferred phosphate for use in the present invention. The suitable amount of the phosphate is 3 to 10% by weight, preferably 5 to 7% by weight. If the compounding amount is less than 3% by weight, the synergistic effect with the PTFE is not exhibited, and if the compounding amount exceeds 10% by weight, the amount of the lubricating film formed on the counterpart material becomes too large and the wear resistance is deteriorated. The result is a lowering.

The method of compounding the lubricating resin composition in the present invention is not particularly limited, and examples thereof include a method of mixing with a Henschel mixer, a tumbler or the like, and a method of melt-mixing with a single screw or twin screw extruder.

The above-described lubricating resin composition covers the joints 21 of the expanded metal 2, and further includes a mesh 23 of the expanded metal 2, a wedge-shaped engaging portion 22, and each side 24 of the mesh and the back metal 1. It is filled in the minute gap 4 between the inner peripheral surface 11. As a result, the lubricating resin composition forms the slip layer 3 that is firmly integrated with the expanded metal 2. As described above, the sliding layer 3 formed by filling the minute gap 4 together with the wedge-shaped engaging portion 22 is firmly integrated with the expanded metal 2, so that the sliding layer 3 is worn and the expanded metal 2 is removed. Even when exposed, the lubricating resin composition filled in the mesh 23 of the expanded metal 2 can maintain good friction and wear characteristics.

The multilayer sliding member of the present invention is manufactured as follows. The first manufacturing method is a method for manufacturing a multilayer sliding member having an inner diameter that is relatively small, specifically, an inner diameter of less than about 40 mm. First, a steel pipe having a predetermined size is prepared as the back metal 1. Then, an expanded metal 2 made of a copper alloy is prepared, and the expanded metal 2 is pressed in the thickness direction to crush the sharpened tip of each joint 21 of the expanded metal 2 and flatten the front side and the back side of each joint 21. Formed on surface 25. As a method for pressing the expanded metal 2, for example, a method of rolling by a rolling roll is exemplified.

Subsequently, the expanded metal 2 having the flat surface 25 formed on each joint portion 21 is inserted along the inner peripheral surface 11 of the back metal 1, and the inner peripheral surface of the back metal 1 is caused by the springback force of the expanded metal 2. The expanded metal 2 is held by pressing the flat surface 25 of each joint portion 21 against 11.

Next, the back metal 1 holding the expanded metal 2 under pressure is charged into a heating furnace adjusted to an inert gas atmosphere, a reducing gas atmosphere or a vacuum atmosphere, and
Heating is performed at a temperature of 000 ° C. for 20 to 60 minutes, and each bonding portion 21 of the expanded metal 2 is diffusion-bonded to the inner peripheral surface 11 of the back metal 1. As a result, a sliding member base in which the expanded metal 2 is integrally joined to the inner peripheral surface 11 of the back metal 1 is obtained.

In the sliding member base obtained by the above-described steps, a wedge-shaped engaging portion 22 is formed between each connecting portion 21 and the inner peripheral surface 11 of the back metal 1. Each side 24 of mesh 2 and inner peripheral surface 1 of back metal 1
The mesh 23 of the expanded metal 2 is continuous via the minute gap 4 between the meshes 1.

Inserting a core inside the sliding member base,
After setting this in a mold of an injection molding machine, a lubricating resin composition is injection-molded in the gap between the inner surface of the sliding member base and the core. By this step, the surface of the expanded metal 2 is covered with the lubricating resin composition, and the lubricating resin composition is filled in the mesh 23, the wedge-shaped engaging portion 22, and the minute gap 4 of the expanded metal 2. 3 and a multilayer sliding member is obtained.

Next, a second manufacturing method of the present invention will be described. The second manufacturing method is a method for manufacturing a multilayer sliding member when the inner diameter is relatively large, specifically, when the inner diameter is about 40 mm or more. First, in the same manner as in the first manufacturing method, an expanded metal 2 made of a steel pipe and a copper alloy as a back metal 1 is prepared, and the expanded metal 2 is pressurized so that the front side and the rear side of each joint 21 are flat. 25.

Next, the expanded metal 2 having the flat surface 25 formed on each joint portion 21 is wound into a cylindrical shape and inserted along the inner peripheral surface 11 of the back metal 1. At that time, the joint 2
The outer diameter surface of expanded metal 2 defined by 1 is backing metal 1
The expanded metal 2 can be held on the inner peripheral surface 11 of the back metal 1 by its springback force, as in the first manufacturing method. Then, a pipe made of stainless steel is inserted into the inner peripheral surface of the expanded metal 2 held on the inner peripheral surface 11 of the back metal 1 with a minute gap therebetween.

Subsequently, the back metal 1 into which the expanded metal 2 and the pipe are inserted is heated under the same conditions as in the first manufacturing method. In this step, both the pipe made of stainless steel and the back metal 1 are thermally expanded, and at the same time, the contact pressure of the expanded metal 2 interposed between the pipe and the back metal 1 on the inner peripheral surface 11 side of the back metal 1 is further increased. Thereby, each joint 21 of the expanded metal 2 is diffusion-bonded to the inner peripheral surface 11 of the back metal 1, and each joint 21 is joined and integrated to the inner peripheral surface 11 of the back metal 1. Then, after joining the expanded metal 2, the pipe is removed to obtain a sliding member base.

In the sliding member base obtained by the above-described steps, similarly to the sliding member base obtained by the first manufacturing method, each connecting portion 21 and the inner peripheral surface 11 of the back metal 1 are formed.
And a wedge-shaped engaging portion 22 is formed between the inner peripheral surface 11 of the expanded metal 2 and the inner peripheral surface 11 of the back metal 1.
Are continuous. Moreover, when the expanded metal 2 is bonded to the back metal 1, the expanding force of the pipe is applied to the inner peripheral surface side of the back metal 1 holding the expanded metal 2, so that the expanded metal 2 and the back metal 1 are more firmly bonded. Have been.

Next, in the same manner as in the first manufacturing method, a core is inserted into the inside of the sliding member base, and the core is set in a mold of an injection molding machine. The lubricating resin composition is injection-molded in the gap with the child. By this step, the surface of the expanded metal 2 is covered with the lubricating resin composition, and the lubricating resin composition is filled in the mesh 23, the wedge-shaped engaging portion 22, and the minute gap 4 of the expanded metal 2. 3 and a multilayer sliding member is obtained.

In the second manufacturing method, the joining force between the expanded metal 2 and the back metal 1 is further increased by utilizing the expansion force of a pipe made of stainless steel. The dimensional relationship for firm diffusion bonding to the inner peripheral surface 11 is as follows.

In the above joining step, an inert gas atmosphere,
When heated to a temperature T ° C. in a reducing gas atmosphere or a vacuum atmosphere, the expanded metal 2 inserted and held in the back metal 1 made of a steel pipe and the pipe made of stainless steel come into contact with each other, and the gap between the two is reduced to 0 ( In the case of (0), the following equation is established.

[0041]

[Equation 1] Inner diameter of back metal × [1 + 1.2 × 10 ⁻⁵ × (T−room temperature)] − Expanded metal thickness × 2 = outer diameter of stainless steel pipe × [1 + 1.78 × 10 ⁻⁵ × (T−room temperature) ]

In the above equation, 1.2 × 10 ⁻⁵ is the coefficient of thermal expansion of the back metal, and 1.78 × 10 ⁻⁵ is the coefficient of thermal expansion of the stainless steel pipe. In addition, since the thermal stress is easily dispersed in the expanded metal, the amount of thermal expansion of the expanded metal itself can be ignored.

For example, the inner diameter of the back metal is 61.5 m.
m, the thickness of the expanded metal is 0.75 mm, the heating temperature is 900 ° C, and the room temperature is 20 ° C.
0.65 = 1.016 x stainless steel pipe outer diameter, and the stainless steel pipe outer diameter is 59.69 mm. When a stainless steel pipe having an outer diameter of 59.69 mm is used for the expanded metal 2 having an inner diameter of 60 mm, the expanded metal 2 and the stainless steel pipe are in contact with each other, but a contact pressure is generated between the two. Absent.
Therefore, by using a stainless steel pipe having an outer diameter of more than 59.69 mm and less than 60 mm, a high contact pressure can be generated between the two.

[0044]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to embodiments. Example 1 As a back metal, a seamless steel pipe having an inner diameter of 32.2 mm, an outer diameter of 50 mm, and a length of 40 mm (carbon steel pipe ST for machine structure)
KM13C) was used. Expanded metal is 0.
It was prepared by expanding a phosphor bronze plate having a thickness of 64 mm, and the mesh was a diamond-shaped mesh having a length in the short direction of 3.0 mm and a length in the long direction of 4.4 mm. Then, the expanded metal was pressed by a rolling roll to form a flat surface at each joint of the expanded metal. Expanded metal after processing has a thickness of 0.75m
m, the width is 39.5 mm, and the length is 101.2 mm.

Next, the expanded metal was inserted along the inner peripheral surface of the back metal, and each joined portion of the expanded metal was pressed against the inner peripheral surface of the back metal and held by the spring back force of the expanded metal. The inner diameter of the expanded metal at this time is 30.7 mm.

The back metal holding the expanded metal is placed in a heating furnace adjusted to an inert gas atmosphere, heated at 900 ° C. for 60 minutes, and the expanded metal is diffusion-bonded to the inner peripheral surface of the back metal and slid. A member base was produced. In such a sliding member base, a wedge-shaped engaging portion is formed between each joining portion of the expanded metal and the inner peripheral surface of the back metal, and each side of the expanded metal mesh and the inner peripheral surface of the back metal. It was confirmed that minute gaps were formed between the gaps and that the expanded metal mesh was continuous through the minute gaps.

Subsequently, a core having a diameter of 29.1 mm was inserted into the inner peripheral surface of the expanded metal of the sliding member base, and this was set in a mold of a screw type injection molding machine.

As a lubricating resin composition, nylon 66 ("Tismopoticon ONN-30: trade name", manufactured by Otsuka Chemical Co., Ltd.) containing 30% by weight of potassium titanate whisker was used.
5 to 25% by weight (nylon 66: 10.5 to 17.5% by weight, potassium titanate whisker: 4.5 to 7.5% by weight), ethylene tetrafluoride resin ("Teflon 7J" manufactured by Du Pont-Mitsui Fluorochemicals Co., Ltd.) : Trade name) 10-20% by weight, calcium hydrogen phosphate 5-7% by weight, balance nylon 4,6 (manufactured by Nippon Synthetic Rubber Co., Ltd.) were charged into a Henschel mixer and mixed to obtain a lubricating resin composition. Was.

The lubricating resin composition was injection-molded in the gap between the inner surface of the expanded metal and the core in the mold.
After the molding, the inner peripheral surface was machined to obtain a multilayer sliding member having a 0.3 mm-thick sliding layer on the surface of the expanded metal. In the obtained multilayer sliding member, the lubricating resin composition covers the surface of the expanded metal,
In addition, the mesh of the expanded metal, the wedge-shaped engaging portion between each joint of the expanded metal and the inner peripheral surface of the back metal, and the minute gap between each side of the expanded metal and the inner peripheral surface of the back metal are filled in a flowing state. As a result, a slip layer was firmly integrated with the expanded metal. Table 1 shows the component composition of the sliding layer in the multilayer sliding member thus obtained.

Example 2 The back metal had an inner diameter of 62.25 mm, an outer diameter of 75 mm,
A seamless steel pipe having a length of 40 mm (same as that of the first embodiment) was used, and as an expanded metal, the first embodiment was used.
The same as above was used. Rolled in the same manner as in Example 1, the thickness was 0.75 mm, the width was 39.5 mm, and the length was 1
A 95.6 mm expanded metal was obtained. Then, the expanded metal was wound into a cylindrical shape, and the expanded metal was inserted so that the outer surface of the expanded metal was in contact with the inner peripheral surface of the back metal. The inner diameter of the inserted expanded metal is 6
0.75 mm.

Next, an austenitic stainless steel pipe was inserted into the inner peripheral side of the cylindrical expanded metal inserted into the back metal. As a stainless steel pipe, the inner diameter is 54.9 mm, the outer diameter is 60.5 mm, and the length is 40 m
m pipes were used. At that time, the gap between the inner peripheral surface of the expanded metal and the outer peripheral surface of the stainless steel pipe was 0.125 mm.

The back metal into which the expanded metal and the stainless steel pipe were inserted was heated under the same conditions as in Example 1, and the expanded metal was diffusion-bonded to the inner peripheral surface of the back metal. Then, the stainless steel pipe was removed to prepare a sliding member base. In such a sliding member base, Embodiment 1
Similarly to the above, it was confirmed that wedge-shaped engaging portions and minute gaps were formed, and that the mesh of the expanded metal was continuous through the minute gaps.

Subsequently, a core having a diameter of 59.15 mm was inserted into the inner surface of the expanded metal of the sliding member base, and was set in a mold of a screw type injection molding machine.

As a lubricating resin composition, nylon 66 ("Tismopoticon ONN-30: trade name", manufactured by Otsuka Chemical Co., Ltd.) containing 30% by weight of potassium titanate whisker was used.
5 to 25% by weight (nylon 66: 10.5 to 17.5% by weight, potassium titanate whisker: 4.5 to 7.5% by weight), ethylene tetrafluoride resin ("Teflon 7J" manufactured by Du Pont-Mitsui Fluorochemicals Co., Ltd.) : Trade name ") 10-20% by weight, lithium phosphate 5-7% by weight, balance nylon 4,6
(Manufactured by Nippon Synthetic Rubber) into a Henschel mixer,
By mixing, a lubricating resin composition was obtained.

The lubricating resin composition was injection molded in a gap between the inner surface of the expanded metal and the core in the mold.
After the molding, the inner peripheral surface was machined to obtain a multilayer sliding member having a 0.3 mm-thick sliding layer on the surface of the expanded metal. In the obtained multilayer sliding member, the lubricating resin composition covers the surface of the expanded metal,
In addition, the mesh of the expanded metal, the wedge-shaped engaging portion between each joint of the expanded metal and the inner peripheral surface of the back metal, and the minute gap between each side of the expanded metal and the inner peripheral surface of the back metal are filled in a flowing state. As a result, a slip layer was firmly integrated with the expanded metal. Table 2 shows the component composition of the sliding layer in the multilayer sliding member thus obtained.

Comparative Example A cold-rolled steel sheet having a thickness of 1.6 mm was prepared as a metal backing metal, and a copper alloy (C
After sprinkling u90-Sn10) powder, it was sintered in a reducing gas atmosphere at a temperature of 820 to 830 ° C for 40 minutes to form a porous sintered layer having a thickness of 0.4 mm on a steel plate. Then
A resin composition in which 3% by weight of molybdenum disulfide is added as a solid lubricant to a polyamide resin (Nylon 12, manufactured by Daisei Co., Ltd., “Dyamide”) powder is sprayed on the porous sintered layer, and the thickness is kept constant. After flattening the surface, 215
Heated in an electric furnace at a temperature of ２３０230 ° C. for 90 seconds. Then, after rolling with a roll, it was cooled to produce a multilayer sliding member having a 0.3 mm-thick sliding layer on the surface of the porous sintered layer.

Next, the multi-layer sliding member is bent with the sliding layer inside, and the inner diameter is 60.15 mm and the outer diameter is 6 mm.
After winding into a cylindrical shape of 4.75 mm and length of 40 mm,
This was press-fitted into a seamless steel pipe having the inner diameter of 64.75 mm, the outer diameter of 75 mm, and the length of 40 mm (the same as in Example 1) to obtain a cylindrical multilayer sliding member.

Next, the tests performed on the sliding characteristics of the multilayer sliding members obtained in the above-described Examples and Comparative Examples and the results thereof will be described. With respect to sliding characteristics, durability was evaluated by a journal test under the following test conditions.

Journal swing test (durability) Test conditions Surface pressure 30 MPa (306 kgf / cm ² ) Speed 1.2 m / min Test time 50 hr Mate material Carbon steel for machine structure (S45C) Lubrication No lubrication

Table 1 shows the test results obtained under the above test conditions.
And Table 2. (Below)

[0061]

[Table 1] (Below)

[0062]

[Table 2]

In the above journal swing test, the multilayer sliding members of Examples 1 and 2 had a surface pressure of 30 MPa.
a (306 kgf / cm ² ), exhibits a stable performance with a low friction coefficient even under dry friction (no lubrication) under low-speed and high-load conditions at a speed of 1.2 m / min, and the wear amount is 40 μm or less. Excellent performance. On the other hand, in the multilayer sliding member of the comparative example, the friction coefficient increased with the lapse of the test time, and the wear amount also showed a large value.

As described above, according to the multilayer sliding member of the present invention, each joint portion of the expanded metal is diffusion-bonded to the back metal to form a wedge-shaped engagement between the expanded metal and the inner peripheral surface of the back metal. Part, and the mesh of the expanded metal is continuous through a minute gap between each side of the mesh and the inner peripheral surface of the back metal, and the slip layer formed over the surface of the expanded metal is made of poly. It is formed of a lubricating resin composition comprising hexamethylene adipamide resin, ethylene tetrafluoride resin, potassium titanate whisker, phosphate, and the balance polytetramethylene adipamide resin, and the resin composition is expanded metal. Since the mesh, the wedge-shaped engagement portion between each joining portion of the expanded metal and the inner peripheral surface of the back metal and the minute gap between each side of the mesh and the inner peripheral surface of the back metal are filled,
The peel strength of the sliding layer against the backing metal is enhanced, and excellent sliding characteristics are exhibited under severe friction conditions, especially under dry friction conditions.

[Brief description of the drawings]

FIG. 1 is an external perspective view showing a multilayer sliding member according to the present invention.

FIG. 2 is a partially broken plan view showing a state in which the multilayer sliding member according to the present invention is developed.

FIG. 3 is a sectional view taken on line II of FIG. 2;

[Description of sign]

 DESCRIPTION OF SYMBOLS 1 Backing metal 11 Inner peripheral surface 2 Expanded metal 21 Joining part 22 Wedge-shaped engaging part 23 Mesh 24 Side 3 Slip layer 4 Micro gap

Claims (10)

[Claims] 1. A back metal made of a steel pipe, an expanded metal made of a copper alloy integrally joined to an inner peripheral surface of the back metal, and a slip layer of a lubricating resin composition covering the inner surface of the back metal together with the expanded metal. Wherein the lubricating resin composition comprises 5 to 20% by weight of a polyhexamethylene adipamide resin and 5 to 20% by weight of an ethylene tetrafluoride resin.
A multilayer sliding member comprising 20% by weight, 3 to 10% by weight of potassium titanate whisker, 3 to 10% by weight of phosphate, and the balance being polytetramethylene adipamide resin. 2. The multilayer sliding member according to claim 1, wherein the phosphate is selected from lithium phosphate, lithium hydrogen phosphate, lithium pyrophosphate, tricalcium phosphate, calcium pyrophosphate, and calcium hydrogenphosphate. . 3. An expanded metal mesh is formed such that each joining portion of the mesh is diffusion-bonded to the inner peripheral surface of the back metal to form a wedge-shaped engaging portion, and the mesh of the expanded metal is connected to each side of the mesh and the back metal. The multilayer sliding member according to claim 1, wherein the sliding member is continuous through a minute gap formed between the sliding member and the inner peripheral surface of the sliding member. 4. The multi-layer sliding member according to claim 2, wherein the slip layer of the lubricating resin composition is formed by filling a mesh of expanded metal, a wedge-shaped engaging portion and a minute gap. 5. A flat surface is formed on a front surface and a back surface of each connection portion of the expanded metal.
The multilayer sliding member according to any one of the above. 6. The expanded metal according to claim 1, wherein an opening area of one mesh of the expanded metal is 1 to 60 mm ² , and an opening ratio of all meshes of the expanded metal is 30 to 70%. Multi-layer sliding member. 7. A back metal made of a steel pipe, an expanded metal made of a copper alloy integrally joined to an inner peripheral surface of the back metal, and a slip layer of a lubricating resin composition covering the inner surface of the back metal together with the expanded metal. And (1) pressing the expanded metal in its thickness direction to form a flat surface on the front side and the back side of each joint portion of the expanded metal. (B) inserting the expanded metal along the inner peripheral surface of the back metal, and pressing and holding the flat surfaces of the joints on the inner peripheral surface of the back metal by the springback force of the expanded metal; (C) The back metal holding the expanded metal pressed against the inner peripheral surface is placed in a heating furnace adjusted to an inert gas atmosphere, a reducing gas atmosphere or a vacuum atmosphere at a temperature of 800 to 1000 ° C. After leaving for 20 to 60 minutes, each joint of the expanded metal is diffusion-bonded to the inner peripheral surface of the back metal to form a wedge-shaped engagement portion between each joint and the inner peripheral surface of the back metal. A step of obtaining a sliding member base in which the mesh of the expanded metal is continuous via a minute gap between each side of the mesh and the inner peripheral surface of the back metal; and (d) inserting a core inside the sliding member base. After being set in a mold of an injection molding machine, 5-20% by weight of polyhexamethylene adipamide resin and 5% by weight of ethylene tetrafluoride resin are filled in a gap between the inner surface of the sliding member base and the core. ~ 20
Injection molding a lubricating resin composition composed of 3% to 10% by weight, potassium titanate whisker 3 to 10% by weight, phosphate 3 to 10% by weight, and a balance of polytetramethylene adipamide resin; A step of forming a slip layer thereon by injection molding of the resin composition, the resin composition filling the mesh of the expanded metal, the wedge-shaped engaging portions and the minute gaps, and covering the surface of the expanded metal. A method for manufacturing a multi-layer sliding member comprising the above steps (a) to (e). 8. In the step (b), a pipe made of stainless steel is inserted through a minute gap on the inner peripheral side of the inserted expanded metal, and in the step (c), the pipe and the back metal are heated. The method for manufacturing a multi-layer sliding member according to claim 7, wherein the pipe is removed after each joint portion of the expanded metal is diffused and bonded to an inner peripheral surface of a back metal while expanding. 9. The multi-layer slide according to claim 7, wherein the phosphate is selected from lithium phosphate, lithium hydrogen phosphate, lithium pyrophosphate, tricalcium phosphate, calcium pyrophosphate, and calcium hydrogenphosphate. A method for manufacturing a moving member. 10. The expanded metal according to claim 7, wherein an opening area of one mesh of the expanded metal is 1 to 60 mm ² , and an opening ratio of all meshes of the expanded metal is 30 to 70%. A method for manufacturing a multilayer sliding member.