JPH05169225A - Forming device using die - Google Patents

Abstract

PURPOSE:To simplify and miniaturize a device by linking retreating/advancing movement of a core to a cavity with opening/closing movement in a prescribed stroke. CONSTITUTION:Molten metal is injected into the cavity 4 from a sprue gate and after the molten metal solidifies, a movable die 2 is shifted in the die opening direction by an actuator, and the core 3 is descended (retreated) by sliding a guide pin 7 in an inclining hole 13 to separate a protruding part 12 at the tip part of the core 3 from an undercut part A in a product W. Then, at last, by projecting the ejector pins 15, the product W is taken out from the movable die 2.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mold forming apparatus used for casting a product having an undercut portion.

[0002]

2. Description of the Related Art As a conventional mold forming apparatus of this type, for example, those shown in JP-A-63-220965 and JP-A-2-89553 are known.

This mold forming apparatus has a fixed mold fixedly installed on a base member, a movable mold that opens and closes with respect to the fixed mold by the power of an actuator, and a mold opening direction substantially different from that of the movable mold by an actuator. It has a schematic structure with a core for forming an undercut part that moves back and forth in a right angle direction.The core is advanced when the molten metal is injected, and the core is retracted when the product is taken out from the cavity. This prevents the core from interfering with product removal.

[0004]

However, in this conventional mold forming apparatus, in addition to the actuator for moving the movable mold, another actuator for moving the core must be provided, so that the entire apparatus is complicated. However, there is a problem that it becomes larger.

Therefore, the present invention is intended to provide a mold forming apparatus that can move the core forward and backward without using a special actuator, thereby simplifying the entire apparatus and downsizing the apparatus. is there.

[0006]

The present invention is, as one means for solving the above-mentioned problems, a fixed die, a movable die that can be opened and closed with respect to the fixed die, and a core for forming an undercut portion. In a mold forming apparatus in which a cavity is formed by and, the core is slidably supported by either one of a fixed mold and a movable mold, and the backward and forward movement of the core with respect to the cavity is performed during a predetermined stroke of the movable mold. It was linked to the opening and closing movements of.

[0007]

When the movable die is closed with respect to the fixed die during the injection of molten metal, the core moves in the direction of the cavity in conjunction with this, and the core is set at a predetermined undercut forming position. In this state, after pouring the molten metal into the cavity, waiting for the molten metal to solidify and opening the movable mold, the core moves back in the cavity direction in conjunction with this operation,
It will separate from the undercut part of the product. The product is taken out of the movable mold in this state.

[0008]

Embodiments of the present invention will now be described with reference to the drawings.

First, a first embodiment of the present invention will be described with reference to FIGS.

The mold forming apparatus shown in FIGS. 1 and 2 is for casting a product W having an undercut portion A on the rising surface of a hat-shaped cross section. In the drawings, 1 is fixed on a base member (not shown). The fixed die 2 installed is a movable die that opens and closes with respect to the fixed die 1 by the power of an actuator (not shown), and 3 is a core for forming an undercut portion. The cavity 4 for molding the product W is formed by the fixed mold 1, the movable mold 2, and the core 3.

A concave portion 5 forming a part of the cavity 4 is formed on the end surface of the fixed mold 1 facing the movable mold 2, and a concave portion 5 is formed below the concave portion 5 so as to be continuous with the concave portion 5. A groove 6 for fitting the child 3 is formed. A guide pin 7 is provided so as to project downward from the groove 6 at a predetermined angle (in a direction away from the undercut formation position of the cavity 4) at a predetermined angle. In addition, the fixed mold 1,
A lock plate 9 is provided with a fitting hole 8 that traverses the bottom near the lower end of the groove 6 and has a tapered surface 9a at the top.
Can be fitted into the fitting hole 8.

On the other hand, on the end surface of the movable die 2 facing the fixed die 1, the convex portion 10 forming a part of the cavity 4 is formed.
Is formed, and a pin escape hole 11 is formed below the protrusion 10, and the tip of the guide pin 7 is loosely inserted into the pin escape hole 11 when the movable die 2 and the fixed die 1 are closed. It is like this. Furthermore, the protrusion 10 of the movable mold 2
A guide rail (not shown) running in the vertical direction is provided on the lower side of the core 3, and the core 3 is slidably supported by the guide rail. Therefore, the core 3 is slidably supported in a direction (vertical direction) substantially perpendicular to the mold opening direction of the movable mold 2.

The core 3 has a projection 12 which is an undercut forming portion formed on the tip end side, and an inclined hole 13 which forms the same inclination as the guide pin 7 on the base end side.
When the movable mold 2 moves toward the fixed mold 1 when the mold is closed,
The guide pin 7 is slidably fitted in the inclined hole 13. Since the tip end side of the guide pin 7 is inclined downward (in a direction away from the undercut formation position of the cavity 4) at a predetermined angle, and the core 3 is supported so that it can slide only in the vertical direction. During a predetermined stroke of the movable die 2 in which the guide pin 7 engages with the inclined hole 13, the core 3 moves backward and forward (downward and upward) on the guide rail in conjunction with the opening / closing operation of the movable die 2. Type 2
When is completely closed, the projection 12 at the tip of the core 3 is set at a predetermined undercut forming position. Further, a taper surface 3a is formed in the vicinity of the lower end of the core 3 on the fixed mold 1 side, and when the lock plate 9 is fitted into the fitting hole 8 when the mold closing is completed, the taper surface of the lock plate 9 is formed. 9a and the tapered surface 3a of the core 3 come into contact with each other, whereby the core 3 is firmly fixed.

Reference numeral 14 is a stopper that regulates the lowered position (retracted position) of the core 3, and 15 is an extrusion pin for taking out the product W from the movable die 2.

In the above structure, when casting the product W, first, the movable die 2 is moved in the die closing direction by an actuator (not shown) to guide the guide pin 7 and the inclined hole 1.
As the core 3 is raised (advanced) by sliding the core 3, the projection 12 at the tip of the core 3 is set at a predetermined undercut forming position of the cavity 4 as shown in FIG. The lock plate 9 is fitted into the fitting hole 8 to fix the core 3.

Next, in this state, the molten metal is injected into the cavity 4 from a gate (not shown), waits for the molten metal to solidify, and the movable die 2 is moved in the die opening direction by an actuator (not shown) to guide the guide pin 7 and the inclined hole 13. Sliding down the core 3 (retracting) to move the product W as shown in FIG.
The projection 12 at the tip of the core 3 is separated from the undercut portion A of the. Finally, the extrusion pin 15 is projected to take out the product W from the movable mold 2.

Next, the second aspect of the present invention will be described with reference to FIGS.
Examples will be described. The same parts as those in the first embodiment shown in FIGS. 1 and 2 are designated by the same reference numerals.

The mold forming apparatus shown in FIGS.
In the same manner as in the embodiment shown in FIG. 1, a product W having an undercut portion A on the rising surface of the hat-shaped cross section is cast, and this mold forming apparatus also fixes the fixed mold 1 and the fixed mold 1. And a core 103 for forming an undercut portion, and a cavity 4 for molding a product W is formed by the fixed mold 1, the movable mold 2, and the core 103. It is like this.

The fixed mold 1 is provided with a concave portion 5 forming a part of the cavity 4 on the end surface on the side facing the movable mold 2, and the movable mold 2 side is downward at the lower side of the concave portion 5 ( A guide hole 16 is formed which is inclined at a predetermined angle (10 ° to 20 °) in a direction away from the undercut forming position of the cavity 4. The core 103 is slidably supported in the guide hole 16. Core 1
In No. 03, the end face on the front end side and the upper edge portion thereof face the cavity 4, and the projection 12 which is an undercut forming portion is formed on the upper edge portion. Reference numeral 17 in the figure denotes a protrusion for displacement regulation formed on the base of the core 103.
Reference numeral 8 denotes a lid member that also serves as a stopper that regulates the backward movement limit of the core 103.

On the other hand, in the movable die 2, the convex portion 10 forming a part of the cavity 4 is formed on the end surface on the side facing the fixed die 1, and the extrusion pin 15 for taking out the product W is provided. Has been.

In the above structure, when casting the product W, first, the movable die 2 is moved in the die closing direction by an actuator (not shown). At this time, when the movable die 2 moves by a predetermined amount, the end surface of the movable die 2 contacts the tip surface of the core 103 protruding from the guide hole 16, and thereafter the movable die 2 pushes the core 103 into the guide hole 16. Like When the movable mold 2 is closed in this way, the core 103 is completely retracted to the retracted limit as shown in FIG. 3, and the projection 12 formed at the upper edge of the tip of the core 103 is located at a predetermined undercut forming position of the cavity 4. Will be set. Thus, the cavity 4 is formed.

Next, in this state, the molten metal is injected into the cavity 4 from a gate (not shown), the solidification of the molten metal is awaited, and the movable die 2 is moved in the die opening direction by an actuator (not shown). At this time, the product W formed by the solidification of the molten metal adheres to the convex portion 10 of the movable die 2 due to its condensing force, and the projection 12 at the upper end of the core 103 has an undercut portion of the product W. Since the movable die 2 moves in the die opening direction because it is fitted in A, the core 103 is pulled by the product W, slides in the guide hole 16, and gradually protrudes from the guide hole 16. become. When the core 103 begins to project from the guide hole 16 in this manner, the projection 12 at the tip of the core 103 is gradually displaced downward due to the inclination of the guide hole 16, and when the core 103 projects from the guide hole 16 by a predetermined amount, Protrusion 1 as shown in 4
2 separates from the undercut portion A of the product W. Then, after this, the push-out pin 15 is projected to move the product W from the movable mold 2.
Take out.

In the case of this injection molding apparatus, the core 103
Retreats with respect to the guide hole 16 when the movable die 2 is closed and protrudes when the movable die 2 is opened, but with respect to the cavity 4, it moves forward when the movable die 2 is closed and retracts when the movable die 2 is opened. ..

Further, in comparison with the injection molding apparatus shown in FIGS. 1 and 2, the injection molding apparatus is provided with a guide rail for supporting the core (3 in FIGS. 1 and 2) on the movable mold 2 or a fixed mold. 1
Since there is no need to provide a guide pin (7 in FIGS. 1 and 2) and a lock plate (9 in FIGS. 1 and 2) for fixing the core when the mold is closed, the number of parts is reduced. There is an advantage that the structure is small and the size can be further reduced.

[0025]

As described above, according to the present invention, the core is slidably supported by either one of the fixed type and the movable type, and the backward and forward movement of the core with respect to the cavity is performed during a predetermined stroke of the movable type. Since it is interlocked with the opening and closing operation of the core, it becomes possible to move the core forward and backward with respect to the cavity by using the opening and closing power of the movable mold, and it is not necessary to provide a dedicated actuator for moving the core forward and backward. For this reason,
The whole device is simplified and downsized as compared with the conventional one.

[Brief description of drawings]

FIG. 1 is a sectional view showing a first embodiment of the present invention.

FIG. 2 is a sectional view showing the same embodiment.

FIG. 3 is a sectional view showing a second embodiment of the present invention.

FIG. 4 is a sectional view showing the same embodiment.

[Explanation of symbols]

1 ... Fixed type, 2 ... Movable type, 3 ... Core, 4 ... Cavity,
103 ... Nakako.

Claims (1)

[Claims] 1. A mold forming apparatus in which a cavity is formed by a fixed mold, a movable mold that can be opened and closed with respect to the fixed mold, and a core for forming an undercut portion, wherein the core is a fixed mold. A mold forming apparatus, which is slidably supported by one of the movable dies, and the retracting and advancing operation of the core with respect to the cavity is interlocked with the opening / closing operation of a predetermined stroke of the movable die.