JP2003056569A - Resin-bearing component and manufacturing method for the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a resin-bearing component, having a cylindrical electrocast portion molded integrally in a shaft hole through insert molding, and to provide a manufacturing method for the same, in particular suitable for a bearing portion requiring highly precise rotation, sliding or sliding rotation. SOLUTION: The resin-bearing component comprises the cylindrical electrocast portion 3 as an electrocast shell previously separated from a master shaft 4 suitable to the shaft hole of the bearing component 13, the electrocast portion 3 integrally molded in the shaft center of a resin-molded portion 11 through insert molding. The manufacturing method for the resin bearing component comprises a step of fabricating an electrocast shaft 4 having the cylindrical electrocast portion 3 suitable to the shaft hole provided on the outer periphery of the master shaft 1, a step of separating the electrocast shaft 4 into the master shaft 1 and the cylindrical electrocast portion 3, and a step of injection molding the cylindrical electrocast portion 3 as the electrocast shell mounted in a core rod 12 in a die to form the bearing component 13, having the electrocast portion 3 which is integrally molded in the shaft center of the resin molded portion 11.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resin-made bearing part in which a shaft part is fitted into a shaft hole so as to engage and support the two parts so that they can rotate or slide relative to each other. The present invention relates to a bearing component and a manufacturing method thereof, and is particularly suitable for a resin bearing component that requires highly precise rotation or sliding or sliding rotation and a manufacturing method thereof.

[0002]

2. Description of the Related Art This type of resin bearing parts is used for general bearing parts such as gears and cams, sensors, potentiometers, etc. because of their light weight, small inertial force and mass production capability. Alternatively, it is widely used for bearings of high precision parts such as actuators.

Among these high precision parts, for example, in the case of a bearing portion in a lens holder for performing optical pickup in an optical information recording / reproducing apparatus, precise roundness and inner diameter dimensional precision are required. Clearance with a few μ
The following are required, and high mechanical strength and slidability against a load are also required.

However, when the injection-molded resin bearing component is used as it is, precise roundness and inner diameter dimensional accuracy cannot be obtained due to heat shrinkage and orientation, and the weld line lowers mechanical strength. , Attach a sleeve made of aluminum alloy, etc. to the inner peripheral surface of the molded product,
The lubricative resin pipe was insert-molded.

[0005]

However, when a sleeve made of aluminum alloy or a lubricating resin pipe is used, in order to obtain precise roundness and inner diameter dimensional accuracy,
There is a problem that needs to be solved, such as the need for precision cutting and polishing, which results in higher costs and lower productivity.

Therefore, the present invention proposes a resin bearing part and a method of manufacturing the same which can solve the problems of the prior art. However, a cylindrical electroformed part is insert-molded on the inner peripheral surface of the shaft hole of the resin bearing part. And a method of manufacturing the same, which is particularly suitable for a bearing portion that requires highly precise rotation or sliding or sliding rotation.

[0007]

In a resin bearing component according to the present invention, a tubular electroformed part, which is an electroformed shell separated in advance from a master shaft adapted to the shaft hole of the bearing component, has a shaft of the resin molded part. The core is integrally molded by insert molding.

According to this resin bearing component, since the inner peripheral surface of the electroformed portion which is the electroformed shell forms the shaft hole of the bearing component, the roundness and the inner diameter dimensional accuracy are high and the slidability is good. Yes, there is no need to perform post-treatment such as polishing, and the clearance for the shaft parts used by mounting on the inner peripheral surface of the electroformed part is minimized to enable highly precise rotation or sliding or sliding rotation. In addition, the adhesive force of the resin molding portion to the outer peripheral surface of the electroformed portion is good.

The method of manufacturing a resin-made bearing component according to the present invention comprises the steps of producing an electroformed shaft having a cylindrical electroformed portion fitted to the shaft hole on the outer periphery of the master shaft, and using this electroformed shaft as the master shaft. The process of separating into a tubular electroformed part, the tubular electroformed part which is an electroformed shell is mounted on the core rod in the mold and injection molding is performed, and the electroformed part is attached to the shaft center of the resin molding part. And a step of forming an integrally molded bearing part.

According to this method for manufacturing a resin bearing component,
Since the inner peripheral surface of the electroformed portion, which is the electroformed shell with the master shaft separated, forms the shaft hole of the bearing component, a resin bearing component with high roundness and inner diameter dimension accuracy can be obtained.

In the above-described method of manufacturing a bearing part made of resin, the master shaft separated from the electroformed part can be repeatedly diverted as a master shaft for producing a new electroformed shaft, whereby the same master can be used. Since a large number of bearing parts can be manufactured based on the shaft, it is possible to economically obtain a homogeneous product with no dimensional accuracy variation.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION A resin bearing component and a method for manufacturing the same according to the present invention will be described below in detail with reference to the accompanying drawings of FIGS. Thus, using the master shaft 1 as an electrocast master, electroforming is performed in a state where the non-electroformed part 2 of the master shaft 1 is masked, and the electroformed shaft 4 provided with the tubular electroformed part 3 is manufactured.

The master shaft 1 is made of a material having high mechanical strength such as rigidity, good slidability, and excellent heat resistance and chemical resistance. In the illustrated embodiment, it is hardened. A straight columnar peeling shaft made of stainless steel is used. Among stainless steels, SUS420J is particularly preferable.

The material of the master shaft 1 is not limited to stainless steel, and it is also possible to use another material having the same performance and capable of processing the electroformed part 3 and separating electroforming. For example, a hard metal material such as nickel chrome steel or other nickel alloy or chrome alloy, or a ceramic having a hard metal coating on its surface can be used.

The shape of the master shaft 1 may be not only a peeled shaft but also a hollow shaft or a solid shaft in which a resin material is embedded in a hollow portion, and when the resin bearing component is a sliding shaft. Has a polygonal shape or other non-circular shape if the cross section is constant, and depending on the application of the resin bearing component, it is possible that the cross section shape is not constant over the entire length of the shaft. Is.

For masking the non-electroformed part 2, a resist treatment or ink-containing ink is silk-printed to attach an acid-resistant and non-conductive covering material to the outer peripheral surface of the non-electroformed part 2.
A protective coating is formed that acts only on the electroformed portion 3 of the master shaft 1 during the electroforming treatment.

Various kinds of electroformed metal can be used for the electroformed portion 3 as in the case of known electroforming, but in the illustrated embodiment, the same stainless steel material as the master shaft 1 is used. In order to facilitate the separation of the above, a sliding material such as carbon and a stress relaxation agent such as saccharin are included.
The thickness of electroforming is about 0.2 to 0.3 mm.

When the master shaft 1 is subjected to electroforming, both end sides of the electroformed portion 3 protrude into the non-electroformed portion 2 and a tapered chamfered portion 3a is naturally formed on the inner peripheral surface. However, the chamfered portion 3a is useful for separating the electroformed portion 3 from the master shaft 1 and for attaching and detaching the shaft component to be mounted on the inner peripheral surface of the electroformed portion 3 of the bearing component 13.

That is, when the electroformed part 3 is separated from the master shaft 1, for example, high-temperature or low-temperature high-pressure air is blown to the joint portion to utilize the difference in thermal contraction rate between the two, or in the axial direction. Although chamfered, the chamfered portion 3a is convenient for blowing high-pressure air, and also acts as a guide when attaching and detaching the shaft component.

Next, as shown in FIG. 2, the electroformed shaft 4 shown in FIG. 1 is separated into a master shaft 1 and an electroformed part 3 as shown in FIG. In the illustrated embodiment, the electroformed portion 3 is provided at one location of the short master shaft 1 to make one by one, and the separated master shaft 1 can be repeatedly used as an electroformed master.

Further, in order to mass-produce the electroformed part 3, a large number of electroformed parts 3 may be produced at one time by performing electroforming treatment on a plurality of locations on the long master shaft 1. It is also possible to adopt a mode in which a cast portion is made and then cut into a fixed length by laser processing or the like.

The electroformed part 3, which is an electroformed shell, is mounted on the outer periphery of the core rod 14 as an insert part in a cavity 10 of an injection molding die having an upper die 5 and a lower die 6 as shown in FIG. A resin material such as liquid crystal polymer (LCP) is injected through the spool 7, the runner 8 and the gate 9 to perform injection molding.

Liquid crystal polymer (LC
In addition to P), it is possible to use crystalline polymers such as polyphenylene sulfide (PPS) resin, polyacetal resin, and polyamide resin, and other high-performance resin materials exhibiting similar functions, as required. You may add the additive which becomes a fiber reinforcement and a lubricant.

As a result, as shown in FIG. 4, it is possible to obtain the bearing component 13 in which the electroformed portion 3 which is the electroformed shell is integrally formed on the inner peripheral surface of the shaft hole of the resin molded portion 11. The inner peripheral surface of the shaft hole of the component 13 has a high dimensional accuracy adapted to the outer peripheral surface of the master shaft 1.

Since the outer peripheral surface of the electroformed portion 3 is rough and the inner peripheral surface thereof is smooth due to the basic properties of electroforming, the inner peripheral surface of the electroformed portion 3 is located inside the shaft hole of the resin molding portion 11. The adhesion of the peripheral surface is good, and the slidability with respect to the shaft used by being mounted on the inner peripheral surface of the electroformed part 3 of the bearing component 13 is also good, and it is not necessary to perform post-treatment such as polishing. .

Further, the master shaft 1 separated from the electroformed part 3 can be repeatedly used as an electroformed master and is economical, and since many bearing parts 13 are manufactured from the same electroformed master, dimensional accuracy, etc. A homogeneous product with no variation can be obtained.

If a bearing component having a shaft hole electroformed is manufactured by the conventional technique, the shaft hole of the resin-molded portion previously injection-molded will be electroformed later. Since it is extremely difficult to place an electrode in the shaft hole, mask the non-electroformed part, perform uniform and constant electroforming in the shaft hole, etc. In the invention, the practical use is made possible by using the means described above.

[Brief description of drawings]

FIG. 1 is a front view of a master shaft (a) and an electroformed shaft (b) used in a method for manufacturing a resin bearing component according to the present invention.

2 is a vertical cross-sectional view of a separation step in which a master shaft is separated from the electroformed shaft of FIG. 1 to obtain an electroformed portion.

3 is a schematic longitudinal sectional view of an essential part of injection molding performed by inserting the electroformed part of FIG.

FIG. 4 is a vertical cross-sectional view of a bearing component with an electroformed portion obtained by injection molding of FIG.

[Explanation of symbols]

1 master axis 2 Non-electroformed part (masking) 3 Electroformed part 4 Electroformed shaft 5 Upper mold 6 Lower mold 7 spool 8 runners 9 gates 10 cavities 11 Resin molding part 12 core rod 13 Bearing parts

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Eiji Watanabe             316 Kamihirama, Nakahara-ku, Kawasaki City, Kanagawa Prefecture             Ceremony company Odensha (72) Inventor Kenichi Mitani             7-48-3 Nishi Kamata, Ota-ku, Tokyo Co., Ltd.             In Act One F-term (reference) 3J011 QA02 QA05 SC03 SC13 SC20                 4F206 AD03 AD19 AH14 JA07 JB12                       JB20 JF05

Claims (3)

[Claims] 1. A cylindrical electroformed part, which is an electroformed shell separated in advance from a master shaft that fits into a shaft hole of a bearing component, is integrally formed by insert molding on the shaft center of the resin molded part. Made of resin bearing parts. 2. A step of producing an electroformed shaft in which a cylindrical electroformed portion matching the shaft hole is provided on the outer periphery of a master shaft, and the electroformed shaft is separated into a master shaft and a tubular electroformed portion. The process and the process of mounting the tubular electroformed part, which is an electroformed shell, on the core rod in the mold and performing injection molding to form a bearing component in which the electroformed part is integrally formed with the shaft center of the resin molded part. A method of manufacturing a resin bearing component provided. 3. A master shaft separated from a resin molded product,
The method for manufacturing a resin bearing component according to claim 2, wherein the resin bearing component is repeatedly used as a master shaft for manufacturing an electroformed shaft.