JPH08197225A - Method for clamping die having slide core - Google Patents

Abstract

PURPOSE: To carry out the casting of a thin product by making the die clamping force between a fixed die and a movable die and the fastening force of a slide core with a tapered core the fixed value. CONSTITUTION: The tapered ring 4 is fitted to the fixed die 1 as shiftably in the die opening/closing direction by action of a cylinder 8. The tapered ring 4 is vertically moved in the horizontal state by simultaneously working plural cylinders 8. A pressure adjusting device 17 for pushing the tapered ring 4 to the slide core 3 at the desirable pushing force is connected with the cylinders 8. The pushing force between the inner peripheral tapered surface 4a of the tapered ring 4 and the outed paripheral tapered surface 3a of the slide core 3 is held to a prescribed force by acting the force of the die opening direction on the tapered ring 4 with the working of the cylinders 8, and the die clamping force between the fixed die 1 and the movable die 2 and the fastening force of the slide core 3 with the tapered ring 4 are made to be the desirable fixed value. By this method, the safety operation can be executed without developing bur during operating.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of clamping a die casting die, and more particularly, to prevent burrs from blowing in a die having a plurality of slide cores.
The present invention relates to a method useful for vacuum casting.

[0002]

2. Description of the Related Art Conventionally, for example, when an aluminum wheel for an automobile is molded by die casting, for example, as shown in FIG.
As shown in Fig. 2, fixed mold 1, movable mold 2, and movable mold 2 are divided into left and right parts, and the mold is opened and closed in a direction perpendicular to the axial direction. Of the slide core 3 and a die made of a taper ring 4 for pressing the slide core 3 which prevents the slide core 3 from opening during casting. The taper ring 4 is fixed to a fixed die holder 7, and further, It was attached to the fixed platen 10.

The movable mold 2 is mounted on a movable plate 11 via a movable mold holder 9 and driven by a mold clamping cylinder (not shown). Tie bar 12 is tie bar nut 13
Thus, the fixed platen 10 and the mold clamping cylinder are connected. 5
Is a cavity, 14 is a casting sleeve, 15 is a plunger tip, and 16 is a plunger.

When casting is performed using such an apparatus,
The slide core 3 is divided by the core cylinder 6,
After that, the die casting machine is clamped, and the movable die 2 and the slide core 3 are fitted to the fixed die 1. In that case, the outer peripheral portion of the tip of the slide core 3 has a taper surface 3a, and when the slide core 3 is inserted into the taper recess 4a on the inner periphery of the taper ring 4 attached to the fixed mold 1, the slide core 3 is caused by the casting pressure. It prevents it from opening.

[0005]

As can be seen from the above, for example, when casting an aluminum wheel,
In order to take out the product, it is necessary to make a part of the die on the outer periphery of the product open and close the slide core 3 of 40 or 20 parts.

On the other hand, when the mold is clamped, all the contact surfaces must be in contact with the mating side in order to perform sealing for vacuum casting while preventing burr blow. However, when pouring is started, the molten metal enters the cavity 5 on the inner surface of the slide core 3, the slide core 3 receives the heat, and the temperature rises significantly, while the molten metal does not directly contact the taper ring 4. The temperature of the taper ring 4 does not rise so much that a temperature difference occurs between the two.

For example, when the temperatures of the slide core 3 and the taper ring 4 are the same at the start of operation, the contact surface between the slide core 3 and the fixed mold 1, the slide core 3 and the taper ring 4 are formed.
When the operation is started after adjusting the clearance of the contact surface to 0, the temperature of the slide core 3 rises with the lapse of time, the outer diameter of the slide core 3 increases due to thermal expansion, and the taper increases. The contact surface with the ring 4 rises upward, and a gap is created in the contact surface between the slide core 3 and the fixed mold 1.

If the gap between the two molds is set to 0 in a state where there is a temperature difference, there will be a gap between the slide core 3 and the taper ring 4 at the time of start, and the slide will occur when the casting pressure is applied. A gap will be created on the circumferential split surface between the cores 3. Although a slight difference can be corrected by elastic deformation due to the mold clamping force, a large correction cannot be made. Therefore, burrs are easily blown and it is difficult to perform vacuum casting.

[0009]

According to the present invention, in order to solve such a problem, a fixed mold on the lower side, a movable mold on the upper side, and a direction perpendicular to the axial direction of the mold opening / closing direction. A mold that has multiple slide cores that can be opened and closed and that are mounted on a movable mold, and a mold that has a taper ring for pressing the slide core that is mounted on a fixed mold so that each slide core does not open during casting. In the method of clamping the mold using
The force of the die opening direction is applied to the taper ring by the action of the cylinder to keep the pressing force between the inner peripheral taper surface of the taper ring and the outer peripheral taper surface of the slide core at a specified force, and to keep the force between the fixed mold and the movable mold The mold clamping force and the taper ring clamping force of the slide core were set to a desired constant value.

[0010]

[Operation] The mold is clamped with the slide core closed. Even if the outer peripheral surface of the slide core comes into contact with the taper ring first during mold clamping, the force of the hydraulic cylinder for tapering is smaller than the mold clamping force, so the slide core contacts the fixed mold and performs mold clamping. When casting is performed, a force for opening the die is generated due to the casting pressure, but if the die clamping force is large, it does not float between the movable die and the fixed die.

Further, since the slide core is fastened by a taper ring having a rigidity that is several times the force of the hydraulic cylinder for taper ring and has a high rigidity depending on the taper angle, it does not open even when a casting pressure is applied. When casting is completed, the mold is opened, the movable mold is lifted by the movable plate, then the slide core is opened, and the cast product is taken out.

[0012]

1 and 2 show a case where a die is attached to a vertical die casting machine as one embodiment of an apparatus for carrying out the present invention, and the same parts as those of the conventional apparatus shown in FIG. The same reference numerals as those in FIG. 4 are used, and the description thereof is omitted. The casting sleeve 14 and the plunger 16 are, for example, Japanese Patent Publication No.
By the method described in No. 7-20061 and Japanese Patent Publication No. 57-21414, the operations of pouring, tilting, docking, and injecting are performed, and casting is performed in the cavity 5.

As shown in FIG. 1, a taper ring 4 is attached to a fixed mold 1 so as to be movable in the mold opening / closing direction by the action of a cylinder 8 for pressing the taper ring. This cylinder 8
As can be seen from the diagram on the left side of FIG. 2, a plurality of cylinders are provided in the circumferential direction, such as four, and a plurality of cylinders 8 are simultaneously operated to smoothly move the taper ring 4 up and down in a horizontal state. I was able to move it.

Then, the taper ring 4 is attached to the slide core 3
A pressure adjusting device 17 for pressing with a desired pressing force is connected to the taper ring pressing cylinder 8. As the pressure adjusting device 17, a commonly used relief valve was opened. 18 is a pump, 19 is a four-way switching valve, and 20 is a tank.

Next, the operation of the present invention will be described. The slide core 3 which is divided and opened is closed, and the mold is clamped in a stationary state. At that time, the taper ring 4 floats above the lower die holder 7 via the hydraulic cylinder 8. The pressure acting on the hydraulic cylinder 8 is the pressure adjusting device 1
It is kept at a predetermined constant pressure by the action of 7. Therefore,
When the movable platen 11 descends, first, the outer peripheral tapered surface 3a of the slide core 3 comes into contact with the inner peripheral tapered recess 4a of the taper ring 4.

Since the force of the mold clamping cylinder is larger than the force of the hydraulic cylinder 8, the slide core 3 moves down while pushing down the tapering 4. At this time, since the contact surface of the slide core 3 with the taper ring 4 is tapered, the slide core 3 descends in a state of being clamped by a force several times the force of the hydraulic cylinder 8, and the lower surface of the slide core 3 is fixed. Touch the top surface of the and stop.

Although the magnification of the force for tightening the slide core 3 varies depending on the taper angle and the friction coefficient, the hydraulic cylinder 8
The optimum value can be obtained and set together with the force of. If the mold is clamped by this method, the contact surface between the slide core 3 and the fixed mold 1 and the circumferential split surface 3b of the slide core 3 will be described.
Since both contact surfaces can be sealed with a constant contact surface pressure regardless of the temperatures of the slide core 3 and the taper ring 4, when the inside of the cavity 5 is evacuated before casting, it is not Air can be prevented from entering, and even if the casting pressure is applied when the casting is completed, the gap is small and burr does not blow.

When the casting is completed and the cast product is cooled, the mold is opened as shown in FIG. 3, the slide core 3 is also opened, and the cast product 21 is taken out. At this time, the force of the hydraulic cylinder 8 and other structures are determined so that the taper ring 4 does not rise due to the frictional force with the slide core 3.

In the first embodiment, first, the taper ring 4 is slightly lifted from the upper surface of the lower mold holder 7 by the action of the hydraulic cylinder 8, and the mold is clamped in this state. 2. As the slide core 3 descends, the taper ring 4 is pushed down by the slide core 3 so that the lower surface of the slide core 3 contacts the upper surface of the fixed mold 1 to obtain a predetermined mold clamping force. At this time, the pressing force between the slide core 3 and the taper ring 4 is set to a predetermined force by the action of the hydraulic cylinder 8, but this is performed by clamping the mold with the taper ring 4 lowered. After the lower surface of the tape comes into contact with the upper surface of the fixed mold 1 and a predetermined mold clamping force is obtained, the hydraulic cylinder 8 is actuated to raise the taper ring 4, and the inner peripheral taper surface 4a of the taper ring 4 is slid onto the slide core. 3 on the outer peripheral taper surface 3a It may be pressed in. In any case, even if the temperature of the mold changes, the mold clamping force,
The tightening force of the slide core 3 by the taper ring 4 can be set to a desired constant value, the gap between the slide core 3 and the fixed mold 1 can be eliminated, and burrs can be reliably and easily prevented from blowing.

[0020]

According to the present invention, the taper ring for tightening the slide core is attached to the lower die holder through the hydraulic cylinder, so that the fixed die can be operated regardless of the temperature change of the slide core and the taper ring during operation. The gap between the slide mold and the movable die, and the gap on the split surface of the slide core
Therefore, it is possible to perform stable operation without blowing burrs during operation, to make the inside of the mold vacuum, and to prevent air entrapment even during high-speed casting. Therefore, it is possible to cast thin products.

[Brief description of drawings]

FIG. 1 is a vertical sectional view showing an embodiment of an apparatus for carrying out the present invention.

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

FIG. 3 is a vertical cross-sectional view showing a state in which a product is opened and a product is taken out in an embodiment of an apparatus for carrying out the present invention.

FIG. 4 is a vertical sectional view showing an example of a conventional device similar to the device for carrying out the present invention.

[Explanation of symbols]

 1 Fixed Mold 2 Movable Mold 3 Slide Core 3a Slide Core Outer Tapered Surface 4 Tapered Ring 4a Tapered Ring Inner Tapered Surface 5 Cavity 6 Core Cylinder 7 Fixed Die Holder 8 Cylinder 10 Fixed Plate 11 Movable Plate 14 Casting Sleeve 15 Plunger Tip 16 Plunger 17 Pressure regulator

Claims (1)

[Claims] 1. A lower fixed mold and an upper movable mold,
Mold opening / closing direction A plurality of slide cores that are attached to the movable mold by being divided so that they can be opened / closed in the direction perpendicular to the axis.
In the method of clamping the die using a die with a taper ring for pressing the slide core that is attached to the fixed die so that each slide core does not open during casting, the direction of die opening by the action of the cylinder on the taper ring Is applied to keep the pressing force between the inner peripheral taper surface of the taper ring and the outer peripheral taper surface of the slide core at a specified force, and the mold clamping force between the fixed mold and the movable mold and the slide core by the taper ring. Clamping method for a die having a slide core whose clamping force is set to a desired constant value.