JP2005282642A - Insert fitting for resin pulley and resin pulley formed by insert-molding the insert fitting - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an insert fitting for a resin pulley having excellent mechanical strength and appearance and capable of being manufactured at low costs without damaging various properties of the insert fitting of the resin pulley, and the resin pulley formed by insert molding the insert fitting. <P>SOLUTION: This insert fitting for the resin pulley is a cylindrical fitting and has a first groove formed along the circumferential direction and a second groove formed along a direction inclined to the circumferential direction, on the outer peripheral face of the fitting. Preferably, the width of the first groove and second groove is 0.5 mm to 5 mm, and the depth is 0.5 mm to 5 mm. Further preferably, the cross sectional shapes of the first groove and the second groove are approximately semicircular. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a resin pulley insert fitting and a resin pulley formed by insert molding the insert fitting.

A typical pulley is a power steering pulley for a four-wheeled vehicle steering system. For power steering pulleys, heat resistance, wear resistance, oil resistance, and particularly mechanical strength in a high and low temperature atmosphere are required from the usage environment, and thus metal pulleys have been mainly used. However, metal pulleys have problems such as heavy weight, processing time, and high cost.
On the other hand, molding materials in which a base material such as glass fiber is blended with a thermosetting resin such as a phenol resin are excellent in various points such as heat resistance, chemical resistance and mechanical strength. For the purpose of weight reduction, there is an increasing demand as a substitute material for various metal parts including the automobile field. Many techniques are disclosed regarding the shape of the insert fitting inserted into such a resin pulley (see, for example, Patent Documents 1 and 2).
However, in conventional insert fittings, a serrated groove is provided on the outer periphery of the fitting to prevent rotation with the resin pulley, which is the basic performance of the insert fitting, and a concave groove is provided in the middle of the fitting to prevent removal. However, it took a long time to process and the cost was increased.

JP-A-9-155920 JP-A-11-300787

  The present invention has been made as a result of studying various shapes in order to solve the above-mentioned problems without impairing the basic performance of the resin pulley insert metal fitting. Inserting the insert fitting for resin pulley and insert metal fittings that can select the metal fitting procurement method according to the production situation of the resin pulley by providing the spiral groove with a shape that achieves both the function of preventing rotation and retaining with the pulley A resin pulley is provided.

Such an object is achieved by the present invention described in the following (1) to (5).
(1) A cylindrical insert fitting for a resin pulley, the first groove formed on the outer peripheral surface of the metal fitting along the circumferential direction and the first groove formed along the circumferential direction. An insert fitting for a resin pulley, comprising two grooves.
(2) The insert fitting for a resin pulley according to (1), wherein the first groove and the second groove have a width of 0.5 to 5 mm and a depth of 0.5 to 5 mm.
(3) The insert fitting for a resin pulley according to (1) or (2), wherein the cross-sectional shapes of the first groove and the second groove are substantially semicircular.
(4) The insert fitting for a resin pulley according to any one of (1) to (3), wherein the insert fitting for the resin pulley is made of carbon steel for cold heading.
(5) A resin pulley, wherein the resin pulley insert fitting according to any one of (1) to (4) is insert-molded.

  According to the present invention, even when producing a small lot of resin pulleys, which is difficult with conventional insert fittings, it is possible to manufacture insert fittings by full cutting including rotation prevention grooves and slip prevention grooves. Therefore, the insert fitting for resin pulleys obtained by the present invention can be manufactured at a lower cost than conventional insert fittings, and can be used for various applications as a resin pulley having excellent characteristics.

The resin pulley insert fitting of the present invention will be described below.
The present invention is a cylindrical insert insert for a resin pulley, and is formed on the outer peripheral surface of the metal fitting along a circumferential direction and a first groove formed along the circumferential direction. A resin pulley insert metal fitting having a second groove, and a resin pulley formed by insert-molding the insert metal fitting.

FIG. 1 shows the shape (an example) of a resin pulley according to the present invention.
An insert fitting 2 is insert-molded at the center of the resin pulley 1 in the resin pulley 1.

2A and 2B show an insert fitting 2 according to the present invention, in which FIG. 2A is a plan view, FIG. 2B is a sectional view taken along line BB in FIG. 2A, and FIG. 3 is a hole for press-fitting the shaft of the power steering pump. The first groove 4 is a groove formed along the circumferential direction on the outer peripheral surface of the insert metal fitting 2, and prevents the insert metal fitting 2 from coming off from the resin pulley 11 in the vertical direction when resin enters the groove during molding. The purpose is to do. The second groove 5 is a groove formed on the outer peripheral surface of the insert fitting 2 in a direction inclined with respect to the circumferential direction, and is intended to prevent the insert fitting 2 from coming off in the rotational direction from the resin pulley 1. Yes.

The first groove 4 in FIG. 2 is formed in the upper part of the second groove 5, but is not particularly limited. Even if it is formed in the lower part of the second groove, the first groove 4 has a function of preventing vertical slipping. Have.
Moreover, although the 2nd groove | channel 5 is formed only in 1 round in the outer periphery of the insert metal fitting 2 in FIG. 2, it is not specifically limited, You may have a some groove | channel. Further, even if the first groove 4 and the second groove 5 partially intersect with each other, it does not matter as long as there is no hindrance to the removal preventing function.

The width of the first groove 4 and the second groove 5 is preferably 0.5 to 5 mm, more preferably 1 to 3 mm. If the amount is less than the lower limit, the amount of resin entering the groove is small, and the effect of preventing the resin from coming off in the vertical direction and the rotational direction may be reduced. If the upper limit is exceeded, the mechanical strength of the insert fitting 2 may be weakened.
Further, the depth of the first groove and the second groove is preferably 0.5 to 5 mm, and more preferably 1 to 3 mm. If the amount is less than the lower limit, the amount of resin entering the groove is small, and the effect of preventing the resin from coming off in the vertical direction and the rotational direction may be reduced. If the upper limit is exceeded, the mechanical strength of the insert fitting 2 may be weakened.

  The cross-sectional shapes of the first groove 4 and the second groove 5 in FIG. 2 are substantially semicircular, but are not particularly limited. For example, the first groove 4 and the second groove 5 are processed into shapes such as a semi-oval, a semi-elliptical, and a quadrangle It doesn't matter. When the semi-circular shape is used, the groove can be easily processed.

  In the present invention, the material used for the insert fitting is not particularly limited, but it is preferable to use carbon steel for cold heading. By using carbon steel for cold forging, it is easy to cold work when making insert metal fittings, and various metal fitting machining methods can be selected.

  At the time of molding, the insert fitting is incorporated in the cavity of the molding die body, and after molding, it is taken out in a state of being integrated with the molded body. The molding method used here is not particularly limited, but a compression molding method in which uniform pressure is applied to the entire resin pulley and no weld is generated is preferable.

Hereinafter, the present invention will be specifically described based on examples of molding a resin pulley.
The used molding material is a phenol resin molding material mainly composed of glass fiber, and the shape of the resin pulley is roughly as shown in FIG.
The resin pulley molded body 1 has an outer diameter of 145 mm and a height of 30 mm. An insert metal fitting 2 having an outer diameter of 31 mm and a height of 21 mm is inserted in the center, and four holes having a diameter of about 30 mm are formed on the outer side every 90 °.

1. Manufacture of the insert metal fitting 2 The insert metal fitting 2 was produced by the following process using carbon steel for cold heading.
(1) Preparation of material A pipe material having an outer diameter of 32 mm and an inner diameter of 16 mm manufactured by Mitsumune Seisakusho (product number G-3445) was prepared.
(2) Peripheral processing The outer peripheral surface was finished to an outer diameter of 31 mm by cutting.
(3) End face processing The end face was cut.
(4) Peripheral groove machining The first groove 4 formed on the outer peripheral surface along the circumferential direction and the spiral groove 5 that is the second groove formed along the direction inclined with respect to the circumferential direction are cut. Thus, a width R of 1.5 mm and a depth of 1.5 mm were finished.
(5) Inner diameter machining The inner diameter was finished to 16.5 mm by inner diameter cutting.
(6) Cutting It was finished to 21.5 mm in total length by cutting.
(7) End surface processing The end surface was processed by cutting and finished to a total length of 21 mm.
(8) Plating processing Plating processing was performed.
(9) Dimensions of the insert fitting 2: outer diameter 31 mm, inner diameter 16.5 mm, total length 21 mm (FIG. 2)
(10) Spiral groove: width R1.5mm, depth 1.5mm, pitch 7mm (Figure 2)

2. Production of Resin Pulley Molded Body 1 The insert metal fitting 2 obtained as described above was incorporated as an insert in the mold body, and compression molded under conditions of a temperature of 175 ° C., a pressure of 10 MPa, and a curing time of 300 seconds. After mold opening, the insert fitting 2 was taken out from the mold body together with the resin pulley molded body 1 by extrusion.

3. Evaluation The obtained resin pulley molded body 1 was measured and evaluated for appearance, molding workability, rotational torque with the metal fitting 2 that is the mechanical strength of the resin pulley, and removal strength. The molding workability was also excellent.

(Evaluation methods and results)
(1) Appearance The molded resin pulley was visually evaluated. There was no damage such as chipping around the inserted insert fitting 2, and the entire molded body had a good appearance.
(2) Molding workability The molding workability was evaluated based on the ease of handling when the insert fitting 2 was inserted into the mold body during molding. The time required to insert the metal fitting was only a few seconds, and the molding workability was good.
(3) Rotational torque and pull-out strength of resin pulley 1 and insert metal fitting 2 With respect to the rotational torque of resin pulley molded body 1, a resin is provided by forming a key groove in the center hole of insert metal fitting 2 and inserting a dedicated jig there. The pulley 1 was fixed, and the holding force until the insert fitting 2 started to rotate by rotating the dedicated jig was measured.
Moreover, about the pulling-out strength of the insert metal fitting 2 from the resin pulley molded object 1, the insert metal fitting 2 was pushed with the strength tester in the state which fixed the resin pulley 1, and the load when the resin pulley 1 destroyed was measured.
The measurement results of the rotational torque and the pull-out strength were as shown below, and sufficiently cleared the mechanical strength required for the resin pulley.
Rotational torque: 250 Nm, pull-out strength: 10 kN

  The insert fitting for a resin pulley of the present invention can be suitably used for a resin pulley that can produce a groove for preventing rotation and slipping out by pre-cutting and has excellent characteristics at low cost even in small lot production.

An example of the resin pulley of this invention is shown, (a) is a top view, (b) is AA sectional drawing of (a). The insert metal fitting of this invention is shown, (a) is a top view, (b) is BB sectional drawing of (a), (c) is a side view.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Resin pulley 2 Insert metal fitting 3 Shaft press-fit hole 4 1st groove | channel 5 2nd groove | channel (helical groove)

Claims (5)

A cylindrical resin pulley insert metal fitting, the first groove formed along the circumferential direction on the outer peripheral surface of the metal fitting, and the second groove formed along the direction inclined with respect to the circumferential direction An insert metal fitting for a resin pulley, characterized by comprising: The insert fitting for a resin pulley according to claim 1, wherein the first groove and the second groove have a width of 0.5 to 5 mm and a depth of 0.5 to 5 mm. The insert fitting for a resin pulley according to claim 1 or 2, wherein the first groove and the second groove have a substantially semicircular cross-sectional shape. The resin pulley insert fitting according to any one of claims 1 to 3, wherein the resin pulley insert fitting is made of carbon steel for cold heading. A resin pulley, wherein the resin pulley insert fitting according to any one of claims 1 to 4 is insert-molded.

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