JP2552837B2 - Mold clamping mechanism - Google Patents

Description

TECHNICAL FIELD The present invention relates to an improvement of a mold clamping mechanism of a direct pressure mold clamping device, and more particularly,
The present invention relates to a mold clamping mechanism applicable to a die-casting device for highly efficiently casting a heat-treatable non-porous die-cast product which has excellent strength characteristics and does not contain harmful porosity inside.

(Prior art and its problems) Conventionally, the mold clamping device of the die casting machine is structurally classified into a direct pressure type, a toggle type, a wedge lock type, and a combination type. From the work performance, the direct pressure type is superior, and from the mold clamping performance, It is said that the toggle type is excellent.

Such a direct pressure type is a type in which a mold clamping force is directly applied to a mold by a mold clamping hydraulic pressure or a hydraulic cylinder, but in a large apparatus, a very large mold clamping force is required as a maximum mold clamping force. , Auxiliary cylinder type and pressure boosting cylinder type mold clamping mechanisms are used to move the mold clamping ram at high speed up to the full stroke of mold clamping and then press the mold with high pressure. However,
In either method, since the mold clamping ram moves along the entire stroke together with the movable base plate, the amount of hydraulic pressure required for work is large, and there is a limit to shortening the work process and reducing the equipment cost.

Further, in the case of such a direct pressure type, since a large mold clamping cylinder that moves the entire mold clamping stroke is installed on the movable base plate, for example, there is an auxiliary cylinder type in which an auxiliary cylinder is provided separately from the mold clamping cylinder. However, as shown in FIG.
In the case of the vertical type, not only is it very tall, but the equipment installed on the movable base plate moves the entire stroke of the mold clamping, so it has to be a large-scale equipment. However, there is a tendency to adopt a horizontal mold clamping mechanism exclusively.

Further, regardless of whether it is a vertical type or a horizontal type, there is a disadvantage that the dies attached to the movable base plate and the fixed base plate are very troublesome to replace due to their structure.

On the other hand, in the field of die casting, the present inventor eliminates the drawbacks of various conventional die casting methods, and produces high quality castings equivalent to or better than the gravity die casting method or low pressure die casting method, and higher than or equal to the conventional die casting method. We provided a die-casting method and a die-casting device that enable mass production with high efficiency.However, in this method, a small gap over the entire mating surface of the fixed die and the movable die before the completion of die clamping is skillfully used. Although it is important to secure an exhaust passage with a cross-sectional area that is 10 times larger than that of the conventional method, it is important to use the method in which the mold clamping ram moves through the entire stroke of the conventional mold clamping process.
There is a problem that it is difficult to accurately secure a small gap over the entire mating surface of the fixed mold and the movable mold before the completion of mold clamping.

(Problem of the Invention) A first object of the present invention is to provide a mold clamping mechanism which can be used in a mold clamping device requiring a very large mold clamping force and has a low equipment cost and a high work efficiency.

A second object of the present invention is to provide a mold clamping mechanism in which the height of the equipment is minimized to reduce the weight and the mold can be easily replaced even when applied to a direct pressure type vertical mold clamping device. .

A third object of the present invention is to skillfully utilize a small gap over the entire mating surface of the fixed mold and the movable mold before the completion of mold clamping, and achieve a high vacuum instantly to obtain a non-porous die cast product. It is an object of the present invention to provide a mold clamping mechanism suitable for carrying out a new die casting method for manufacturing.

A fourth object of the present invention is to provide a mold clamping mechanism which has a high work efficiency, minimizes equipment height, and is easy to replace the mold when the above new die casting method is carried out in a vertical die casting apparatus. .

(Means for Solving the Problem) In view of the fact that the limit of the conventional direct pressure system is the structure for moving the mold clamping ram having a large diameter over the entire stroke, the present invention incorporates the mold clamping ram in the movable base plate. The small-diameter opening / closing cylinder moves the movable base plate at high speed, while the large-diameter mold clamping cylinder moves the mold clamping ram within the movable base plate to operate only the small stroke required for final mold clamping. The present invention was completed in view of the fact that a maximum mold clamping force can be applied to a mold to provide a mold clamping mechanism that is low in facility cost and excellent in work efficiency, which is the first problem.

Further, the mold clamping mechanism can be applied to both the vertical mold and the horizontal mold. Especially, in the vertical mold clamping device, one mold clamping cylinder is incorporated in the movable base plate, and the opening / closing cylinder of the movable base plate is fixed. If it is installed below, not only can the equipment height of the mold clamping device as the second subject be reduced as a whole, but also the movable base plate can be pulled out upward together with the mold, and the mold replacement becomes extremely easy. I found that and was completed.

Further, according to the present method in which the moving mechanism of the mold clamping ram and the moving mechanism of the movable base plate are separated, the above-mentioned third problem is caused by the simple mechanism that the moving stroke of the movable base plate is set smaller than the total stroke of the mold clamping. It was found that a small gap can be accurately set on the mating surface between the movable mold and the fixed mold after the movement of the movable base plate, and the mold clamping mechanism suitable for implementing the new die casting method was completed. It is a thing. This mechanism can be applied to both vertical and horizontal types. In particular, when applying it to a vertical die casting machine, one mold clamping cylinder is installed in the movable base plate, and the open / close cylinder of the movable base plate is fixed. If it is installed below the plate and the moving distance of the movable base plate is adjusted by the contact position between the guide tube that guides the tie bar and the movable base plate, the minimum equipment height and easy mold replacement are possible. There is an advantage that a direct pressure type die casting device can be provided.

That is, the structure of the horizontal mold clamping mechanism on which the present invention is premised is, as shown in the principle thereof in FIG. 1, "a fixed die 10 and a movable die 10 are mounted on the fixed base plate (1) and the movable base plate (2), respectively. In a mold device that attaches the mold 20 and moves the movable base plate (2) with respect to the fixed base plate (1) to open and close and clamp the mold, the movable base plate (2) is used as the small diameter opening / closing cylinder 21. The movable base plate (2) has a large diameter die clamping cylinder.
22 is incorporated and the mold clamping ram 23 is moved within the movable base plate (2) to clamp and open the movable mold 20 with respect to the fixed mold 10. " In the drawing, (3) is a clamp mechanism capable of fixing the movable base plate (2) to the tie bar 24, (5) is an injection cylinder,
(4) shows an extrusion cylinder.

The structure of the vertical mold clamping mechanism on which the present invention is premised is, as shown in the principle thereof in FIG. 2, "a fixed mold plate (1) and a movable mold plate (2) have a fixed mold 10 and a movable mold, respectively. In the vertical mold clamping device, in which 20 is mounted, and the upper movable base plate (2) is moved up and down with respect to the lower fixed base plate (1) to open and close the mold and clamp the mold, below the fixed base plate (1). The small-diameter opening / closing cylinder 21 is erected, penetrates through the fixed base plate (1) and extends upward, and the movable base plate (2) is connected via a tie bar 24 connected to the movable base plate (2).
While moving the high-speed opening and closing, while incorporating a large-diameter mold clamping cylinder 22 in the movable base plate (2) (in the drawing, the movable base plate (2) and the mold clamping cylinder 22 are integrally formed), By moving the mold clamping ram 23 in the movable base plate (2), the movable mold 20 is clamped and released from the fixed mold 10. " In the drawing, the same members as those in FIG. 1 are indicated by the same numbers, and (6) is a fixing mechanism of the movable base plate (2) to the tie bar 24.

A first configuration of the present invention is to configure a die casting device by adopting the above mold clamping mechanism, and as shown in FIG.
"Fixed dies for fixed base plate (1) and movable base plate (2) respectively
In a die casting device in which the movable base plate (2) is attached to the movable mold 20 and the movable base plate (2) is moved with respect to the fixed base plate (1) to open and close and clamp the mold, the movable base plate (2) is opened and closed for a small diameter. While the cylinder 21 is used for high-speed opening and closing movement, a large capacity mold clamping cylinder 22 is incorporated in the movable base plate (2), and the movable mold 20 built in the movable base plate (2) is used as the fixed mold 10. Cylinder for small-diameter opening and closing, which is configured to be moved by clamping.
The moving stroke Lo of the movable base plate (2) by 21 is set to be ΔL smaller than the total mold clamping stroke L, and when the movable base plate (2) is moved by the full stroke, the mating surface between the movable mold 20 and the fixed mold 10 is set. In such a state, the movable base plate (2) is locked by, for example, the clamp mechanism (3), and the movable mold 20 is fixed by the large-diameter mold clamping cylinder 22. The mold clamping and the mold opening can be moved. ” In the drawing, the same members as those in FIG. 1 are designated by the same reference numerals.

In the present invention, the gap ΔL between the mating surfaces of the movable mold 20 and the fixed mold 10 may be set by providing a positioning protrusion 24a at the lower end of the tie bar 24 so that the level can be adjusted, as shown in FIG. However, a guide tube 25 may be used as shown in FIG.

That is, the second configuration of the present invention is that "first, the tie bar 24 supporting the movable base plate (2) is slidable in the guide tube 25 fixed to the fixed base plate (1), and then,
The movable base plate (2) and the tie bar 21 are reconfigured so as to be opened and closed at high speed by the small capacity opening / closing cylinder 21 installed below the fixed base plate (1), and the guide tube 25 and the movable base plate (2) are moved. ), The moving stroke Lo of the movable base plate (2) by the small capacity opening / closing cylinder 21 is set to be smaller than the total mold clamping stroke L to provide a compact die casting device having a low overall height. As a result, as is clear from a comparison between FIGS. 3 and 4, the overall height is low, and the mold can be easily taken out and replaced by taking out the movable base plate (2).

(Examples) Hereinafter, the present invention will be described in detail based on specific examples shown in the accompanying drawings.

FIG. 5 is a cross-sectional view showing a concrete example in which the mold clamping mechanism according to the present invention is applied to an aluminum die-cast vertical machine, in which the left half surface is obliquely crossed at 45 ° and the right half surface is crossed at 90 °.

In the drawing, (1) is a fixed base plate, and a fixed mold is mounted on the upper surface.
10 is arranged and supported on the gantry F via the support legs L.
On the other hand, (2) is a movable base plate, in which a movable die 20 is arranged on the lower surface, and while being supported by a tie bar 24, it is vertically opened and closed by a small diameter hydraulic cylinder 21, and the mold clamping ram 23 is moved to a large diameter cylinder. 22 (in the drawing, it is formed integrally with the movable base plate (2)) enables fine movement in the vertical direction in the movable base plate (2).

Although the single large-diameter cylinder 22 is shown in the drawing, it may be arranged at four corners. In short, it is sufficient that the mold clamping ram 23 can apply the maximum mold clamping force with a small stroke.

Specifically, the fixed mold 10 on the upper surface of the fixed base plate (1) is
The fixed mold 10 and the movable mold 20 are connected by the plunger 53 of the injection cylinder (5) that communicates with the injection sleeve 51 protruding from the upper surface of the fixed base plate and hangs down the molten metal supplied from the hot water supply pipe 52.
It can be press-fitted into the cavity C after the mold clamping.

Further, guide tubes 25 for vertically slidably guiding the diver 24 are vertically fixed at four corners of the fixed base plate (1). A hydraulic cylinder 21 fixed on the gantry F is connected to the lower end of the tie bar 24 protruding below the fixed base plate (1) through the guide tube 25 so as to move the tie bar 24 up and down.

Further, a tie bar clamp mechanism (3) is provided continuously to the lower end of the guide cylinder 25 protruding below the fixed base plate (1),
The tie bar 24 lowered to the lowest limit by the small capacity cylinder 21 is gripped and fixed.

If the tie bar clamp mechanism (3) is of a split nut type that fits into a groove 24b formed at a required position on the lower end of the tie bar 24, the clamp is accurately fixed.

On the other hand, the movable base plate (2) is fixed to the upper end of the tie bar 24 protruding from the guide cylinder 25. The movable base plate (2) has a large-diameter die clamping hydraulic clamping ram 23 provided in the center through an annular fixing flange 26, and the movable die 21 is fixed to the clamping ram 23. While the mold is clamped, the hydraulic pressure is supplied to 27 parts.
Further, (4) is an extrusion cylinder fixed to the mold clamping ram 23, and an extrusion rod 41 extending from the mold clamping ram 23 penetrates the rear concave portion 29 of the movable mold 20. The extrusion plate 42 is moved up and down inside, and the product is taken out after the mold is opened via the extrusion pin 43.
Incidentally, 44 is a guide pin and 45 is a spacer.

(Operation) In the apparatus having the above-described configuration, the upper end contact portion 24a of the tie bar 24 and the upper end 25a of the guide tube 25 are positioned so that the movable stroke L of the tie bar is shorter than the total mold clamping stroke L by ΔL. When the movable base plate (2) is lowered by the small diameter cylinder 21 and the lower end of the tie bar 24 is gripped and fixed by the tie bar clamp mechanism (3) at the position shown in FIG. 5, the mating surface of the movable die 20 and the fixed die 10 is fixed. A gap of ΔL is accurately formed in the mold, and the inside of the mold including the cavity C is blocked from the outside air by a seal ring or the like (not shown). Therefore, at the same time when the molten metal is injected into the injection sleeve 51 through the hot water supply pipe 52, the injection plunger 53 is moved forward to close the hot water supply pipe port 52a and the cavity C
The air inside the cavity including the cavity C and the air inside the cavity inside the injection sleeve 51 is provided by a vacuum suction device (not shown) inside the cavity C through the exhaust holes 11 on the fixed die 10 located around the cavity. Start suction and discharge of.

At this time, the air in the cavity C passes through the exhaust passage having a large cross-sectional area formed by the gap ΔL left over the entire mating surfaces of the fixed mold 10 and the movable mold 20, and then passes through the fixed mold.
Inside the vacuum tank by a vacuum suction device equipped with a large capacity vacuum tank through an exhaust hole (not shown) communicating with the annular exhaust groove 11 provided between the movable mold 20 and the movable mold 20. Is instantaneously sucked and discharged.

Further, the air in the void inside the injection sleeve 11 merges with the air in the cavity C and is similarly instantaneously discharged.

In this way, the inside of the mold and the inside of the injection sleeve are instantaneously brought to a high vacuum with a degree of vacuum of 99.9% or more, so that the mold clamping operation is started by the mold clamping ram 23 immediately after the start of suction and discharge.

First, when pressure is applied from the hydraulic line to the mold clamping portion 27 of the large-diameter hydraulic cylinder 22 that is integrally formed on the movable base plate (2), the mold clamping portion 27 has a large pressure receiving area.
Since the movable stroke of is a slight movement of ΔL, a large mold clamping force is applied to the movable mold 20 by a small amount of oil.

In this way, when the gap between the mold mating surfaces becomes zero, at the same time, the injection plunger 53 is advanced at a high speed to inject and fill the molten metal in the injection sleeve 11 into the cavity C, and the suction / discharge operation is stopped.

As a result, the vacuum suction device continues to operate even during injection filling, so the gas component released from the molten metal during injection filling is sucked and discharged to the outside through the exhaust groove 11 provided in the die mating surface, and gas is discharged. The molten metal containing almost no solid is solidified in the cavity C in a vacuum state, and a completely non-porous die cast product containing no porosity is completed.

On the other hand, when the mold opening 28 of the large-diameter hydraulic cylinder 22 is pressurized from the hydraulic line, the movable mold 20 moves together with the mold clamping ram 23.
Since the mold clamping is released to the state shown in FIG. 3, the movable base plate (2) is then moved from the position shown by the small-diameter opening / closing cylinder 21.
When is raised, the mold release is completed.

(Effects of the Invention) As is apparent from the above description, according to the present invention, the large-diameter mold clamping cylinder is incorporated in the movable base plate, and the movable base plate is moved at a high speed by the small-diameter opening / closing cylinder separately provided. Since the final maximum mold clamping force is performed by the fine movement of the mold clamping cylinder incorporated in the movable base plate, compared to the conventional system in which the mold clamping ram also moves with the movement of the movable base plate, Not only is it simpler and much lighter and smaller, but the installation cost is lower.

Also, the casting cycle time is shortened.

Further, according to the present invention, since the small-diameter opening / closing cylinder 21 can be installed below the fixed base plate to form a vertical mold clamping device, in addition to the above effects, the overall height of the device becomes extremely low, and at the time of mold replacement. Since the movable base plate (2) can be released from the tie bar 24 and pulled out upward, the mold can be easily replaced.

Furthermore, when the present invention is applied to a die-casting machine for manufacturing a non-porous die casting, the moving mechanism of the mold clamping ram and the movable base plate is separated and moved separately, so that the fixed mold before the final mold clamping from the mold clamping stroke. Since it is possible to subtract the gap left on the mating surface of the movable die and the movable stroke to make the movement stroke of the movable base plate, there is an advantage that the gap control is accurate and the non-porous die casting method can be performed without any trouble. .

Furthermore, at the same time when the moving stroke of the movable base plate is adjusted, a small-diameter opening / closing cylinder 21 for moving the movable base plate 21.
Since it is possible to install a vertical die casting equipment by minimizing the total height of equipment for performing the above non-porous die casting method,
The mold can be easily replaced.

Although the present invention has been described by taking the die casting device as a specific example, it can be widely used for other mold clamping devices.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing a structure of a horizontal mold clamping mechanism which is a premise of the present invention, FIG. 2 is a configuration diagram showing a structure of a vertical mold clamping mechanism which is a premise of the present invention, and FIG. 3 is the present invention. FIG. 4 is a principle diagram in which the first configuration of FIG. 4 is applied to a vertical die casting device, FIG. 4 is a principle diagram of a vertical die casting device which is the second configuration of the present invention, and FIG. 5 shows a specific configuration of FIG. FIG. 6 is a cross-sectional view, and FIG. 6 is a principle view showing an outline of a case where a conventional horizontal auxiliary cylinder type mold clamping device is changed to a vertical type. (1) ... fixed base plate, (2) ... movable base plate (3) ... clamp mechanism, (4) ... extrusion cylinder,
(5) …… Injection cylinder, (6) …… Movable base plate fixing mechanism, 10 …… Fixed mold, 15 ……
Exhaust groove 20 …… Movable mold, 21 …… Small diameter opening / closing cylinder 22 …… Large diameter mold clamping cylinder, 23 …… Clamping ram, 24 …… Tie bar 25 …… Guide tube

Claims (2)

(57) [Claims] 1. A fixed mold (10) and a movable mold (20) are attached to a fixed base plate (1) and a movable base plate (2) respectively, and the movable base plate (2) is fixed to the fixed base plate (1). In a die-casting device that opens and closes and clamps a mold by moving the movable base plate (2) at a high speed by means of a small-diameter opening and closing cylinder (21), a large movable base plate (2) is used. The small diameter opening / closing cylinder is provided with a diameter die clamping cylinder (22), and the movable die (20) built in the movable base plate (2) is clamped and moved with respect to the fixed die (10). When the moving stroke Lo of the movable base plate (2) by (21) is set to be ΔL smaller than the total mold clamping stroke L, the movable mold (20) and the fixed mold are moved during the total stroke Lo movement of the movable base plate (2). (1
A small gap ΔL is left on the mating surface with the 0), and in this state, the movable base plate (2) is locked and the movable die (20) is fixed by the large diameter die clamping cylinder (22). A mold clamping mechanism characterized by enabling mold clamping and mold opening movement with respect to (10). 2. A fixed base plate (1) and a movable base plate (2) located above the fixed base plate (1) are respectively fixed to a fixed mold (1).
0) and a movable mold (20) are attached, and the movable base plate (2) is moved up and down with respect to the fixed base plate (1) to open and close the mold and clamp the mold. A small diameter opening / closing cylinder (21) below 1)
Is erected, extends upward through the fixed base plate (1), and is opened and closed at high speed through a tie bar (24) connected to the movable base plate (2), while the movable base plate ( 2) Incorporating a large diameter mold clamping cylinder (22) into the mold clamping ram (23)
When the movable mold (20) is clamped and released from the fixed mold (10) by moving the movable base plate (2), the tie bar (24) supporting the movable base plate (2). Is made slidable in a guide cylinder (25) fixed to a fixed base plate (1), and by the contact position of the guide cylinder (25) and the movable base plate (2), the small diameter opening / closing cylinder (21) is used. The moving stroke Lo of the movable base plate (2) is calculated from the total mold clamping stroke L by Δ
When L is set to a small value and a full stroke Lo of the movable base plate (2) is moved, a slight gap ΔL is left on the mating surface between the movable mold (20) and the fixed mold (10). The movable base plate (2) is locked, and the movable mold (20) can be clamped and opened relative to the fixed mold (10) by the large diameter mold clamping cylinder (22). Mold clamping mechanism.