JPH1024447A - Insert molding method of two-layered resin molded part - Google Patents

Abstract

PROBLEM TO BE SOLVED: To fit a two-layered resin molded product so as to make an insert hard to slacken even if load acts repeatedly. SOLUTION: In a method inserting a metal cylindrical insert 3 in the attaching part bolt hole of a two-layered resin molded part formed by injection molding in such a state that the whole of the outer peripheral surface of a core layer 2 composed of a reinforcing fiber resin is coated with a soft skin layer 1, the insert 3 is inserted after or while the skin layer 11 formed to the inner peripheral surface of the attaching part bolt hole part of the two-layered resin molded part in which the insert is inserted is eliminated.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for insert molding a two-layer resin molded part.

[0002]

2. Description of the Related Art Conventionally, there is a handle 20 gripped by a vehicle interior part as shown in FIG. This handle 20 has mounting holes 21 with bolts at both ends thereof, and in order to improve strength and feel when gripped,
There are many injection moldings in which a metal core is covered with a soft resin skin layer.

[0003] In recent years, as shown in FIG.
The core of the handle 20 is injection-molded with a fiber-reinforced resin to form the core portion 2, and the soft resin skin layer 1 and the soft resin skin layer 1 are injection-molded into two layers to give a soft feeling when gripped on the outer peripheral surface. ing.

The handle 20 is fixed to the body or the instrument panel with bolts, but the handle 20 is easily loosened due to the repeated Young's modulus of the resin material is smaller than that of metal due to the repeated grip load. Therefore, as shown in FIG. 2, the metal cylindrical insert 3 is fitted in the mounting hole 21.

[0005]

However, the insert 3 is easily loosened by the repeated gripping load at the contact surface between the metallic tubular insert 3 and the soft resin skin layer 1.

An object of the present invention is to provide an insert molding method for a two-layer resin molded part in which the insert of the two-layer resin molded part is hardly loosened even when a load is repeatedly applied.

[0007]

In order to achieve the above object, a method of the present invention is to provide a two-layer resin molding in which the entire outer peripheral surface of a core layer made of a reinforcing fiber resin is covered with a soft skin layer and injection molded. A method of inserting a metal cylindrical insert into a mounting part bolt hole of a part, wherein a skin layer formed at the time of injection molding is formed on an inner peripheral surface of a mounting part bolt hole part of a two-layer resin molded part into which the insert is inserted. The method is characterized in that the insert is inserted after the deletion.

In addition, a method of inserting a metal cylindrical insert into a bolt hole of a mounting portion of a two-layer resin molded part which is formed by coating the entire outer peripheral surface of a core layer made of a reinforcing fiber resin with a soft skin layer and injection molding. The insert is inserted while the skin layer formed at the time of injection molding on the inner peripheral surface of the mounting portion bolt hole of the two-layer resin molded part into which the insert is inserted is deleted in a semi-hardened state.

In the above method, a notch-shaped shearing blade is provided on an extrusion pin inserted into the center of a mounting hole of the mold by fastening the fixed mold and the movable mold of the injection molding mold, thereby forming a two-layer resin. Is injected from the gate, the extrusion pin is pushed down from the fixed mold of the injection mold toward the movable mold to remove the skin layer, and then a metal cylindrical insert is inserted.

Further, in the above method, the fixed mold and the movable mold of the injection molding die are fastened to each other, and a step and a chip escape groove spirally cut into an extrusion pin inserted into the center of the mounting hole of the die. Is provided, a metal cylindrical insert is mounted in advance before injection molding, a skin layer is injection-molded, and a core portion is injection-molded to form a two-layer resin molded part,
The skin layer is removed by the end of the insert while rotating or pressing the extrusion pin from the movable mold toward the fixed mold direction, and cutting chips are spirally cut into the extrusion pin to remove cutting chips from the chip escape groove. It is to discharge.

[0011] In addition, in the above method, the outer peripheral surface is flat or non-slip processed, and a surface-treated metal cylindrical insert is inserted.

[0012]

Embodiments of the present invention will be described below with reference to the drawings. Embodiment 1 As shown in FIG. 3, a fixed mold 4 and a movable mold 5 of a molding die are clamped to form a runner (not shown) and a cavity to form a mounting hole 21 in FIG. Through the push pin 6. The pushing pin 6 is provided with a cutting blade 61 and a concave portion 62 at its tip.

In the above state, the skin layer 1 is injection-molded, and then the core layer 2 is injection-molded. Thereby, the core layer 2
A two-layer resin molded part covered with the skin layer 1 including the inner peripheral surface of the mounting hole formed by the extrusion pin 6 is molded.

Then, the extrusion pin 6 is pulled down while the two-layer resin molded part is in a semi-cured state. As shown in FIG. 4 by pulling down the push pin 6, the skin layer 11 on the inner peripheral surface of the mounting hole is sheared and removed together with a part of the core layer 2 by the cutting blade 61. While being fitted into the inside 62, the movable mold 5 is pulled out and removed.

Thereafter, a cylindrical metal insert 3 shown in FIG. 8 is fitted into the mounting hole. The insert 3 may be inserted by setting the insert 3 at the upper end of the extrusion pin 6 and press-fitting into the mounting hole of the two-layer resin molded part in the molding die, or by removing the two-layer resin molded part from the molding die. It may be fitted in the mounting hole.

As shown in FIG. 5, the outer surface of the insert 3 fitted into the mounting hole of the two-layer resin molded part has the skin layer 1 removed and the exposed outer core layer 2 is in contact with the core layer 2. In this state, the bolts 7 are inserted through the inserts 3 and attached to the fixed portions with the nuts 8.

As described above, since the outer peripheral surface of the insert 3 is fitted into the core layer 2 which is exposed by removing the skin layer 1, the insert 3 is formed by the rigidity of the core layer 2 made of the reinforcing fiber resin. Even if a load is repeatedly applied to the part, the core layer 2 is resistant to settling, so that the insert 3 does not loosen and secures the fitted state.

[Embodiment 2] As shown in FIG. 6, a fixed mold 4 and a movable mold 5 of a molding die are clamped to form a runner (not shown) and a cavity. The point that the push pin 6 is inserted into the portion to be formed is the same as that of the first embodiment.
Is the same as

In the second embodiment, the guide hole 9 for inserting the push pin 6 into the fixed mold 4 is formed on the same axis as the push pin 6.

A spiral groove 10 (a chip escape groove) is formed on the outer periphery of the tip of the push pin 6, and a recess 63 having a step is formed below the spiral groove 10.

In the case of the second embodiment, the insert 3
6 is set in the recess 63 of the push-out pin 6, and FIG.
The tip of the push pin 6 is fixed to the fixed mold 4 and the movable mold 5 as shown by.
Then, the skin layer 1 is injection-molded in the same manner as in Example 1, and then the core layer 2 is injection-molded. As a result, a two-layer resin molded part in which the core layer 2 is covered with the skin layer 1 including the inner peripheral surface of the mounting hole formed by the extrusion pin 6 is formed.

Then, in a state where the two-layer resin molded part is in a semi-cured state, as shown in FIG. As the push pin 6 rises, the upper end of the metal insert 3 set in the concave portion 63 of the push pin 6 acts as a cutting blade to form a skin layer 1 at a portion that becomes an attachment hole.
1 is removed by shearing, and the removed chips are discharged from the spiral groove 10 to the outside of the mold.

Also in the second embodiment, the rigidity of the core layer 2 made of the reinforcing fiber resin is obtained because the outer peripheral surface of the insert 3 is fitted in the core layer 2 which is exposed by removing the skin layer 1. As in the first embodiment, the core layer 2 is resistant to settling even when a load is repeatedly applied to the portion of the insert 3 so that the insert 3 is not loosened and the fitting state is ensured.

In any of the first and second embodiments, the insert 3 is subjected to a flat surface on the outer peripheral surface as shown in FIG. 8A or a non-slip surface 31 as shown in FIG. The metal cylindrical insert 3 is inserted.

[0025]

As described above, according to the present invention, the core layer made of the reinforcing fiber resin is exposed by removing the skin layer of the mounting hole formed in the two-layer resin molded part, and the exposed core is removed. Since the outer peripheral surface of the insert is fitted into the layer in contact with the layer, the insert is secured without loosening even when a load is repeatedly applied to the insert by the core layer having a strong rigidity.

According to the second aspect of the present invention, the insert is inserted while removing the skin layer with the insert in a semi-hardened state, and the chips are discharged from the spiral groove of the extrusion pin to the outside of the mold, so that the skin is smoothly and rapidly removed. The operation of removing layers and inserting inserts is obtained.

[Brief description of the drawings]

FIG. 1 is a perspective view of a two-layer resin molded part used in the method of the present invention.

FIG. 2 is a sectional view taken along line AA of FIG. 1;

FIG. 3 is a side view showing a molded state of the two-layer resin molded part of Example 1 in the method of the present invention.

FIG. 4 is a cross-sectional view showing a state in which a skin layer of Example 1 is deleted in the method of the present invention.

FIG. 5 is a cross-sectional view of a two-layer resin molded part into which an insert is inserted according to the method of the present invention.

FIG. 6 is a side view showing a molded state of a two-layer resin molded part of Example 2 in the method of the present invention.

FIG. 7 is a cross-sectional view showing a state in which a skin layer according to a second embodiment of the present invention is deleted.

FIG. 8 is a perspective view of an insert used in the method of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Skin layer 2 Core layer 3 Insert 4 Fixed type 5 Movable type 6 Extrusion pin 7 Bolt 8 Nut 9 Guide hole 11 Skin layer 10 Spiral groove 21 Mounting hole 31 Non-slip processing 61 Cutting blade 62 Recess 63 Recess

Continued on the front page (51) Int.Cl. ⁶ Identification code Agency reference number FI Technical display location B29K 705: 00

Claims (5)

[Claims] 1. A method in which a metal cylindrical insert is inserted into a bolt hole of a mounting portion of a two-layer resin molded part which is formed by covering the entire outer peripheral surface of a core layer made of a reinforcing fiber resin with a soft skin layer and injection molding. Wherein the insert is inserted after removing a skin layer formed at the time of injection molding on the inner peripheral surface of the mounting portion bolt hole of the two-layer resin molded part into which the insert is inserted. Insert molding method. 2. A method in which a metal cylindrical insert is inserted into a bolt hole of a mounting portion of a two-layer resin molded part which is formed by covering the entire outer peripheral surface of a core layer made of a reinforcing fiber resin with a soft skin layer and injection molding. Wherein the insert is inserted while removing a skin layer formed at the time of injection molding on the inner peripheral surface of the mounting portion bolt hole of the two-layer resin molded part into which the insert is inserted in a semi-cured state. Insert molding method for layer resin molded parts. 3. A notch-shaped shearing blade is provided on an extruding pin inserted into the center of a mounting hole of a mold by fastening a fixed mold and a movable mold of an injection molding mold, and two layers of resin are injected from a gate. 2. The two-layer resin molded part according to claim 1, wherein the skin layer is removed by pushing down an extrusion pin from the fixed mold of the injection mold toward the movable mold, and then a metal cylindrical insert is inserted. Insert molding method. 4. A step and a chip escape groove formed in a spiral shape are provided on an extrusion pin which is fixed to a fixed mold and a movable mold of an injection mold and is inserted into the center of a mounting hole of the mold. The cylindrical insert is mounted before injection molding, the skin layer is injection-molded, and the core is injection-molded to form a two-layer resin molded part. 3. The method according to claim 2, wherein a skin layer is removed by an end of the insert while rotating or pressing the push-out pin, and chips are discharged from a chip release groove spirally formed on the push-out pin. Insert molding method for two-layer resin molded parts. 5. The insert molding method for a two-layer resin molded component according to claim 1, wherein the outer peripheral surface is flat or non-slip processed and a surface-treated metal cylindrical insert is inserted.