JPH10315280A - Air escape tool for injection molding tool - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an air escape tool for an injection molding tool for forming an entrapped air escape channel for a long period of time without being broken on a raw material joining area of a cavity section along an opening. SOLUTION: A recessed section 5c is formed on areas of a protruded mold side contact area 5a and of a protruded mold 5 intruded onto the downstream side of an inflowing raw material, and a slider 10 being in contact with a recessed mold side contact face area 6a is stored slidably in the opening and closing direction of an injection molding tool on the recessed section. An elastic body 15 for protruding the slider surface from a protruded mold side contact area 5a on the periphery of the slider surface is interposed between a bottom face of the recessed section 5c and the slider 10, and a retracted face retracted from the slider surface is formed on a part of the slider surface so as to form an air escape channel 12b between the slider and the recessed mold side contact face 6a. The downstream side end of the retracted face is communicated with a cavity section 7b on the areas of joining the raw material, and the upstream side end of the retracted face is communicated with an opening end 6c positioned on the recessed mold side contact face area 6a of an air escape hole 6b running through a recessed mold 6.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a convex and concave surface for releasing air that is trapped when an inflowing raw material is diverted in a cavity having an opening shape and then merged downstream. The present invention relates to an air release device of an injection molding die having a contact surface area which is in contact with each other to form an opening in an injection molded product.

[0002]

2. Description of the Related Art When a plate-shaped bumper 2 illustrated in FIG. 7 is injection-molded as an injection-molded product, an opening 1 is formed with, for example, a movable mold 5 as shown in FIGS. Are formed by having contact surface regions 5a and 6a in which the surface of the fixed mold 6 is in surface contact with each other. Then, the raw material is supplied to the cavity corresponding to the bumper 2 from the injection port above the center of the fixed type in the vehicle width direction, and is first divided into both sides along the inflow path indicated by the arrow in FIG.
At the cavity portion 7 along the opening 1 and along the opening 1 on the downstream side thereof, and the cavity portion 7 in an intermediate region at the height thereof.
a and merges into the cavity corresponding to the end of the bumper 2.

However, when there is no opening at the time of merging at the cavity portion 7a, air smoothly escapes from the escape opening at the end of the cavity, but air is caught in the middle, and air is trapped on the way. And poor appearance such as silver stripes. As a countermeasure, the concave side contact surface area 6a
The recessed surface 5b, which is recessed by about 0.02 to 0.03 mm from the original surface of the convex mold 5, is formed in the intermediate height area of the convex contact surface area 5a so as to form the air release groove 8 between the convex mold 5 and the convex mold contact surface area 5a. Has formed. Then, the downstream end is formed so as to penetrate the downstream side so as to communicate with the cavity portion 7b adjacent to the concave side contact surface region 6a in the cavity portion 7a where the raw material joins, and the upstream end is formed by the concave mold 6. It communicates with an opening end 6c located in the concave side contact surface area 6a of the penetrating air release hole 6b. Thereby, the cavity portion 7 of the confluence region
The air entrained in a is exhausted from the air escape hole 6b through the air escape groove 8.

[0004]

However, in this type of injection molding, the clamping force is usually set to several thousand tons as a countermeasure against burrs, so that the contact areas of both the convex mold 5 and the concave mold 6, that is, so-called, There is a problem that the parting line is depressed and the air release groove 8 is crushed with time. Therefore,
A cutting operation for periodically regenerating the air escape groove 8 was required.

In view of the foregoing, the present invention provides an air release device of an injection mold capable of forming an air release groove for entrapped air over a long period of time in a raw material joining region of a cavity portion along an opening without being crushed. The purpose is to provide air.

[0006]

According to the present invention, in order to attain this object, according to the present invention, when the convex mold and the concave mold are closed to each other to form a cavity, the surfaces contact each other. In an injection molding die having a contact surface area forming an opening in an injection-molded article, air entrained when an inflowing raw material is split at an upstream cavity along an opening and then joined at a downstream cavity. An air release device of an injection mold for releasing air, wherein a concave portion is formed in the convex-side contact surface region and a convex region that has entered the downstream side thereof, and a slider abuts on the concave-side contact surface region in the concave portion. Is slidably accommodated in the opening and closing direction of the injection mold, and an elastic body is interposed between the bottom surface of the concave portion and the slider so as to protrude the slider surface from the peripheral convex side contact area therearound. Depression A recessed surface is formed to recede from the slider surface so as to form an air escape groove with the side contact surface region, and the downstream end of the recessed surface is communicated with the cavity portion of the region where the raw material joins, thereby forming a concave mold. An upstream end of the receding surface is communicated with an opening end located in the concave side contact surface region of the air release hole penetrating through the hole.

When the convex and concave molds are closed with a predetermined clamping force, the slider comes into contact with the concave contact surface area and retreats while compressing the elastic body. As a result, the slider surface has
An air escape groove is formed between the partial receding surface and the concave contact surface area. Air entrapped in the confluence area of the downstream cavity portion along the opening flows in at the downstream end of the air escape groove that has entered the downstream cavity portion, and escapes at the upstream end through the air escape groove. It flows into the hole and is exhausted from the recess.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An air release device of an injection molding die according to an embodiment of the present invention will be described with reference to FIGS. In these figures, the same parts as those described in FIGS. 5 to 7 are denoted by the same reference numerals and will not be described in detail. A rectangular slider 1 is provided in a convex side contact surface region 5a forming the opening 1 in the convex die 5 and a region slightly entering the downstream side.
0 is formed in an injection molding die, for example, a concave portion 5c of a corresponding shape that is slidably accommodated in the opening and closing direction of the convex die 5.

This slider has an outer slider 12 slidably guided by a bolt 11 screwed as a guide shaft into the center of the bottom surface of the concave portion 5c, and a concave side contact surface region accommodated in the rectangular concave portion 12a. An inner slider 13 in contact with 6a, an elastic body 15 made of urethane rubber for urging the back surface of the outer slider 12 in the closing direction of the convex 5;
It is composed of a spacer 19 inserted between the bottom surface of the concave portion 12a and the back surface of the inner slider 12. These parts 12, 13, 15, and 19 are supported by inserting the bolts 11 into the respective center holes with a slight gap from the recess 13a of the inner slider 13.

The surfaces of the outer slider 12 and the inner slider 13 are formed in the same plane in contact with the concave contact surface area 6a without the spacer 19 mounted in the recess 12a. The frame shape on the downstream side of the outer slider 12 enters the downstream side from the convex side contact surface region 5a, and has a half width adjacent to the concave side contact surface region 6a and along the downstream side surface of the opening 1. Cavity part 7a in the middle area of the height
Is set so as to communicate with the cavity portion 7b on the side of the contact surface region. On the other hand, the shape of the frame on the upstream side of the outer slider 12 has a half width of the open end 6
It is set to communicate with c.

In assembling, the bolt 11 is inserted into the center hole of the concave portion 13a of the inner slider 13, and the rectangular spacer 19 having a thickness of about 0.02 to 0.03 mm, the outer slider 12, and the elastic body 15 are inserted in this order. Then, the screw thread of the bolt 11 is screwed into the screw hole on the bottom surface of the concave portion 5c. In this state, the rotation of both sliders 12, 13 is restrained by the rectangular recess 5c, the outer slider 12 is slightly retracted from the inner slider 13 by the spacer 19, and the inner slider 13 is restrained by the head 11a. Instead, the elastic body 15 protrudes from the surface around the convex 5 (see FIG. 3).

At the time of injection molding, when the convex mold 5 as a movable mold comes into contact with the concave mold 6 as a fixed mold with a predetermined clamping force,
The inner slider 13 comes into contact with the concave side contact surface area 6 a and retreats while compressing the elastic body 15, and the outer slider 12 occupies a position retracted by the thickness of the spacer 19 in conjunction therewith.
As a result, a square air release groove 12b is formed around the inner slider 13 so as to communicate between the cavity portion 7a serving as a confluence area and the air release hole 6b. As a result, the air entrained in the cavity portion 7a in the intermediate height region along the downstream side surface of the opening 1 flows into the downstream side portion of the outer slider 12, and flows through the upper and lower portions to the upstream side. The air flows into the air release hole 6b at the portion, and is exhausted through the air release hole 6b of the concave mold 6.

The spacer 19 can be selected to have a thickness corresponding to a desired interval between the air release grooves 12b. If the surfaces of the sliders 12 and 13 are deformed in some cases, the bolts 11 are removed and the spacers are adapted. It is also possible to replace it with a thick one.

FIG. 4 shows a slider according to another embodiment of the present invention. The slider 20 is formed by two bolts 21 through a coil spring 22 serving as an elastic body, thereby forming a recess 5c.
It is screwed to the bottom of. Surface 20 of slider 20
In the center portion of a, there is formed a receding surface 25 which traverses in the direction of the flow of the raw material, which is the diameter direction, and is wide at both ends to face the cavity portion 7b and the opening end 6c, respectively. As a result, the slider 2 protruding from the recess 5c
When the surface 20a of the first contact hole abuts against the concave contact surface area 6a, the retreating surface 25 causes the cavity portion 7a and the air release hole 6a.
An air escape groove for communicating between b is formed.

The air release device of the present invention is provided in an injection mold having a convex shape having a relatively large contact surface area at an opening, and this convex shape is fixed unlike the case of the above-described embodiment. It may be a type. The opening may be provided in a cavity other than the above-described square shape, for example, a cavity portion which is a downstream merging area even in the case of a cylindrical shape.

[0016]

According to the first aspect of the present invention, since the slider is displaced following the minute displacement of the parting line, the air escape groove is secured without being crushed with time. Therefore, it is not necessary to periodically regenerate the air escape groove. According to the second aspect of the present invention, the slider is formed of two slider portions which are relatively displaceable and interpose the spacer, so that the thickness width of the air release groove can be adjusted by the thickness of the spacer, and Accordingly, it is possible to compensate even when the slider is deformed due to.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view, taken along the line A of FIG. 5, of an air release device when closing an injection molding die according to an embodiment of the present invention.

FIG. 2 is a schematic front view of an air release device of the injection mold.

FIG. 3 is a cross-sectional view of the air release device before clamping of the injection molding die.

4A and 4B show an air release device of an injection mold according to another embodiment, wherein FIG. 4A is a front view and FIG. 4B is a sectional view.

FIG. 5 is a perspective view of a main part of a damper having an opening to which the present invention is applied.

6A and 6B show a conventional air escape groove. FIG. 6A is a sectional view taken along line A of FIG. 5, and FIG. 6B is a sectional view taken along line B of FIG.

FIG. 7 is a diagram showing a flow path of a raw material into a bumper having an opening.

[Explanation of symbols]

 Reference Signs List 5 convex type 6 concave type 5a convex side contact surface area 6a concave side contact surface area 6b air release holes 7a, 7b cavity portion 10 slider 12 outer slider 12b air release groove 13 inner slider 15 elastic body 19 spacer

Claims (2)

[Claims] When a convex and a concave mold are closed to each other to form a cavity, they flow into an injection mold having a contact surface area where surfaces contact each other to form an opening in an injection molded article. An air release device of an injection molding die for releasing air entrained when raw materials are diverted at the upstream cavity portion along the opening and then merged at the downstream cavity portion, wherein the convex mold A concave portion is formed in the side contact surface region and the convex region that has entered the downstream side, and a slider that abuts the concave mold side contact surface region is slidably accommodated in the concave portion in the opening and closing direction of the injection mold. An elastic body interposed between the bottom surface of the concave portion and the slider for projecting the slider surface from the surrounding convex side contact surface region, and a part of the slider surface; A recessed surface is formed to recede from the slider surface so as to form an air escape groove between the surface of the slider and a downstream end of the recessed surface is communicated with the cavity portion in a region where the raw material joins, and penetrates the concave mold. An air release device for an injection mold, wherein an upstream end of the retreating surface communicates with an open end of the air release hole located in the concave side contact surface region of the air release hole. 2. An outer slider in which a slider is independently slidably guided by a guide shaft projecting from a central portion of a convex concave portion, and an inner slider housed in the concave portion and in contact with a concave side contact surface area. The slider according to claim 1, wherein a spacer is interposed between a bottom surface of the concave portion of the outer slider and a back surface of the inner slider so as to form a receding surface on a surface of the outer slider. Air release tool for injection mold.