JPH05104566A - Manufacture of ring-shaped article, in which synthetic resin is molded integrally onto outer circumference of wheel made of metal - Google Patents

Abstract

PURPOSE:To obtain an end product such as a pulley, a solid tire, etc., without cutting work by integrally molding an elastic synthetic resin onto the outer circumference of a wheel made of a metal through an injection molding method. CONSTITUTION:A ring groove 7 is formed to one surface of a wheel 2 made of a metal, a resin introducing hole 8 communicated with the outer circumference of the wheel 2 from the bottom of the ring groove 7 is formed, the injection gate 9 of a mold 6 for injection molding and the ring groove 7 are conformed, the wheel 1 is changed into the mold 6 for injection molding, and a polyurethane-resin stock solution is press-fitted into a cavity 3 between the outer circumferential groove 10 of the wheel 2 and the mold 6 for injection molding, and cured.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a ring-shaped material such as a vibration-preventing pulley, a door roller, and a solid tire whose inner surface is coated with an elastic synthetic resin.

[0002]

2. Description of the Related Art In a domestic electric washing machine or the like, in order to transmit a driving force of a motor to a rotary shaft of a pulsator or the like, a belt is wound around pulleys fixed to the rotary shafts of the motor and the pulsator, respectively. It is usually done by. Efforts have been made to reduce vibration and noise as much as possible for nighttime use of a washing machine.Therefore, as a pulley with little vibration during transmission, an elastic synthetic resin such as polyurethane resin is used on the inner surface of the pulley groove. Is used. Further, door cars for opening and closing doors of elevators and the like are used in which the inner surface of the outer peripheral groove is coated with an elastic synthetic resin such as polyurethane resin in order to reduce vibration and noise during opening and closing.

Conventionally, this type of elastic resin-coated pulley has been manufactured by a casting method. As shown in FIGS. 1 and 2, a metal wheel 2 is loaded in a casting mold 1 and cast with the wheel 2. A polyurethane resin stock solution is poured into the cavities 3 between the shaping dies 1 and solidified, and a cast product in which the polyurethane resin 4 is integrally formed on the outer periphery of the metal wheel 2 as shown in FIG. 3 is formed. Is subjected to post-processing by mechanical cutting to manufacture a pulley 5 which is a product as shown in the sectional view of FIG. 4a and the plan view of FIG. 4b.

[0004]

According to the above-mentioned conventional method of manufacturing the elastic resin-coated pulley by the casting method, mechanical post-processing is required, and the number of steps is increased. Since most of the molding resin is removed by cutting, the resin loss is large. Therefore, there is a problem that the manufacturing cost of the product increases. Therefore, it is an object of the present invention to provide a method for producing a ring-shaped article in which a synthetic resin is integrally molded into a predetermined final product shape on the outer periphery of a metal wheel without mechanical post-processing.

[0005]

[Means for Solving the Problems] In order to achieve the above object,
As a result of intensive studies by the present inventors, the shape of the final product was directly obtained by press-fitting the resin stock solution into the cavity between the wheel and the mold through the resin introduction hole provided inside the metal wheel by the injection molding method. It was found that the resin can be precisely integrally molded, and the present invention has been completed.

That is, the present invention is a method for manufacturing a ring-shaped material such as a pulley, a door roller, and a solid tire by integrally molding an elastic synthetic resin on the outer periphery of a metal wheel, and in one side of the wheel, an annular groove concentric with the wheel is formed. Or provide an arcuate groove,
A resin introduction hole is provided from the bottom of the annular groove or the arcuate groove to the synthetic resin molding part on the outer periphery of the wheel, and the injection gate of the injection molding die is aligned with the annular groove or the arcuate groove for injection molding. The wheel is loaded in a mold, and the reaction resin stock solution or molten resin is passed from the injection gate through the annular groove or arc-shaped groove and the resin introduction hole into the cavity between the outer circumference of the wheel and the injection molding mold. The gist is a method for manufacturing a ring-shaped object in which a synthetic resin is integrally molded on the outer circumference of a metal wheel, which is characterized by being press-fitted and cured.

An example of the manufacturing method of the present invention will be described in more detail with reference to the drawings. As shown in FIG. 5, a metal wheel 2 shown in FIG. 6 is loaded as an insert into a mold 6 for injection molding that is divided into a plurality of pieces in the radial direction, and a fixed mold 6a and a movable mold 6b are clamped by a mold clamping device. .. An annular groove 7 or an arcuate groove, which is concentric with the wheel 2, is engraved on one surface of the metal wheel 2, and the cavity 3 extends from the bottom of the groove 7.
A resin introduction hole 8 communicating with the above is provided. The injection gate 9 of the injection molding die 6 is provided so as to coincide with the position of the annular groove 7 of the wheel 2.

[0008] The resin stock solution is pressed into the cavity 3 from the injection gate 9 of the injection molding die 6 through the annular groove 7 of the wheel 2 and the resin introduction hole 8. After the resin has hardened, the molded product is taken out of the injection molding die 6 to obtain a ring-shaped product molded into the shape of the final product as shown in FIG.

The ring-shaped material manufactured by the manufacturing method of the present invention includes pulleys for belt transmission, ropeways, pulleys for rope guides such as ski lifts for preventing vibration and noise, as well as solid tires and elevators. The present invention can be applied to all ring-shaped molded articles integrally molded with synthetic resin around the outer periphery of a ring-shaped metal insert such as door rollers for door opening and closing.

The synthetic resin used in the present invention may be any synthetic resin having elasticity such as polyurethane resin or the like, which is a thermoplastic or reaction curable resin and which can be press-fitted in a liquid state. .. In particular, polyurethane resin has suitable elasticity and large mechanical strength, is excellent in durability and wear resistance, and is most suitable for covering grooves of pulleys and for solid tires.

When a reaction-curable polyurethane resin is used, two kinds of reaction liquids are continuously mixed by a mixing head to obtain a polyurethane resin stock solution, and immediately the injection plunger of the injection molding machine causes the wheel 2 from the injection gate 9 through the injection gate 9.
It is pressed into the cavity 3 through the annular groove 7. Further, a thermoplastic polyurethane resin may be used by melting it.

To completely bond the polyurethane resin with an insert such as a metal wheel, the method disclosed in JP-A-1-30
As disclosed in No. 1216, it is desirable to pre-apply a phenol / butyral adhesive on the metal surface of the insert and then top coat with an isocyanate adhesive.

[0013]

EXAMPLE As shown in FIG.
A metal wheel 2 for a pulley having a diameter of 55 mm shown in was loaded as an insert and sealed by a mold clamping device. An annular groove 7 is provided on one surface of the wheel 2, and the wheel 2 is loaded with the surface having the annular groove 7 as the upper surface. The wheel 2 is sandblasted in the outer peripheral groove 10 and then washed with trichlorethylene, and the outer peripheral groove 10 is undercoated with Chemlock 218 (trade name) manufactured by Huson Chemical Co., which is a phenol / butyral adhesive. Approximate amount of free isocyanate remaining 4
% Of the isocyanate adhesive was applied and dried. The polyurethane resin stock solution obtained by mixing the isocyanate component liquid and the polyol component liquid with a mixing head was immediately inserted into the injection molding machine, and passed through the injection groove 9 from the injection gate 9 through the annular groove 7 and the resin introduction hole 8 of the wheel 2. The outer peripheral groove 10 of the wheel 2 and the injection molding die 6
It was press-fitted into the cavity 3 between. After curing in the heated mold, the mold was opened and the molded product shown in FIG. 7 was taken out.

[0014]

According to the manufacturing method of the present invention, by using the precision mold, the final product in which the synthetic resin is integrally molded into an accurate shape on the outer periphery of the metal wheel 2 can be directly molded. Since the resin introduction hole 8 is provided through the inside of the wheel 2, the trace of the injection gate 9 of the injection molding die 6 does not appear as a protrusion on the outer peripheral surface of the molded product.

An annular groove 7 is provided on one side of the wheel 2, and the injection gate 9 of the injection molding die 6 and the annular groove 7 are aligned with each other, so that when the wheel 2 is loaded into the injection molding die 6, It is not necessary to make the injection gate 9 and the resin introduction hole 8 of the wheel 2 coincide with each other, positioning becomes very easy when loading the insert, and it is not necessary to provide a pin hole or the like for positioning the insert in the mold. Instead of the annular groove 7, an arcuate groove formed by a part of the annular groove 7 may be provided. The length of the circular arc can be any length within the range of 10 mm to a semicircle. Even in this case, when the insert is loaded manually or automatically, the injection gate 9 and the circular arc-shaped groove are aligned and positioned. Will be easier.

[0016]

According to the method of manufacturing a ring-shaped article in which a synthetic resin is integrally molded on the outer periphery of the metal wheel of the present invention, the ring-shaped article whose outer periphery is covered with the elastic resin is not subjected to mechanical cutting, and only the injection molding process is performed. Can be molded with. Positioning for loading the insert becomes easy, and it is not necessary to provide a positioning pin or the like on the mold, and an inexpensive mold can be used.

[Brief description of drawings]

FIG. 1 is a front sectional view showing a conventional casting method for producing a synthetic resin-coated pulley.

FIG. 2 is a plan sectional view showing a casting method of manufacturing a conventional synthetic resin-coated pulley.

FIG. 3 is a sectional view of a molded product molded by a conventional casting method.

FIG. 4 is a sectional view (a) and a plan view (b) of a pulley obtained by cutting a molded product molded by a conventional casting method.

FIG. 5 is a cross-sectional view showing an example of a method for manufacturing a ring-shaped material of the present invention.

FIG. 6 is a front sectional view (a) and a plan view (b) of an example of a metal wheel used in the manufacturing method of the present invention.

7 (a) and 7 (b) are a front sectional view (a) and a plan sectional view (b) of an example of a ring-shaped article integrally molded with a synthetic resin on the outer periphery of a metal wheel manufactured by the manufacturing method of the present invention.

[Explanation of symbols]

 1 Mold for casting 2 Wheel 3 Cavity 4 Polyurethane resin 5 Pulley 6 Mold for injection molding 7 Annular groove 8 Resin introduction hole 9 Injection gate 10 Outer peripheral groove

Claims (1)

[Claims] 1. A method for manufacturing a ring-shaped material such as a pulley, a door roller, and a solid tire by integrally molding an elastic synthetic resin on the outer circumference of a metal wheel, and forming a ring-shaped groove or arc shape concentric with the wheel on one surface of the wheel. A groove is provided, and a resin introduction hole is provided from the bottom of the annular groove or the arcuate groove to the synthetic resin molding portion on the outer periphery of the wheel, so that the injection gate of the injection molding die and the annular groove or the arcuate groove coincide with each other. Then, the wheel is loaded into the injection molding die, and the reaction resin stock solution or the molten resin is passed from the injection gate through the annular groove or the arc-shaped groove and the resin introduction hole and between the outer circumference of the wheel and the injection molding die. The method for manufacturing a ring-shaped article, wherein a synthetic resin is integrally molded on the outer circumference of a metal wheel, which is characterized by being press-fitted into the cavity of and cured.