JPS622902B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a casting device equipped with an automatic hot water supply device used in a die casting machine.

[Conventional technology]

In conventional die casting machines, the most suitable casting conditions for die casting, such as casting speed, casting pressure, high speed casting start position, deceleration position, etc., can be set in advance. was configured so that this setting condition could be fixed. In order to stabilize the quality of die-cast products, it is a prerequisite to accurately reproduce the casting conditions set in this way, but this has not been done in practice. The reason for this is that the amount of molten metal or molten alloy (hereinafter simply referred to as molten metal) supplied to the die casting machine varies and is not constant.

Fig. 1 A, B and Fig. 2 A, B explain the situation during this period. In each figure, 1 indicates a fixed plate, 2 indicates a movable plate, and each has a fixed mold 3 and a movable plate. A mold 4 is attached. Both molds 3,
A cavity 5 is formed on the abutting surface of 4. Reference numeral 6 denotes a sleeve, in which a molten metal supply port 7 is formed near its outer end, and a chip 10 fixed to the tip of a rod 9 of a hydraulic cylinder 8 is slidably fitted inside. There is. A lever 11 for detecting the high speed casting start position is provided in the middle of the rod 9, and a limit switch 12 for regulating the high speed casting start position is arranged on the side thereof.

On the other hand, FIG. 3 explains a conventionally used automatic water heater. 16 is supported on the shaft, and the arm 15 is driven so that the ice cube 16 moves along a predetermined trajectory 17.
The molten metal 19 inside is pumped up to the supply port 7 of the sleeve 6.
A molten metal 19 is supplied into the chamber.

[Problems to be solved by the present invention]

In a die casting machine having the above-described known structure, if the amount of molten metal supplied into the sleeve 6 is less than the specified value, as shown in FIG. To start casting, air bubbles are drawn into the die-cast product, resulting in a defective product with cavities.

Also, if the amount of molten metal is more than the specified value, the second
As shown in Figure A, high-speed casting starts when most of the molten metal has entered the cavity 5, and the molten metal that has entered the cavity solidifies, making it impossible to obtain a homogeneous die-cast product. .

As shown in FIGS. 1B and 2B, the thickness of the biscuit 13 varies due to variations in the amount of molten metal.
This will lead to changes in filling time, etc., and will impede the quality stability of die-cast products.

When an automatic hot water supply device as shown in FIG. 3 is used, there is variation in the amount of molten metal supplied by the device, resulting in the above-mentioned drawbacks.

In order to eliminate such shortcomings,
Naturally, the first consideration is to improve the accuracy of hot water supply, but at present, a variation of ±5% is unavoidable.
If you try to achieve even higher precision, the hot water supply cycle will become longer, which will significantly reduce its practicality.

[Means for solving problems]

The present invention was made in order to eliminate the above-mentioned drawbacks of the conventional method, and provides a casting device equipped with an automatic hot water supply device that can maintain constant casting conditions even with the current hot water supply accuracy. be.

In the present invention, in a casting device equipped with an automatic hot water supply device, an arm connecting a drive part of the automatic hot water supply device and a dipstick is equipped with a strain gauge whose displacement changes depending on changes in the weight of molten metal in the dipstick. A load detector was installed, and the structure was equipped with a casting condition setting device that could set casting conditions based on the signal from the load detector.

As a casting condition setting device, a device capable of controlling a high-speed injection start point and a deceleration start point of the injection speed was provided.

[Effect]

When the molten metal is pumped out from the insulating furnace by the automatic hot water supply system, the load applied to the strain gauge is detected by the action of the strain gauge attached to the arm that connects the automatic hot water supply system's drive unit and the water supply system, and the load applied to the strain gauge is detected. Then, the weight of the molten metal in the strainer is calculated by the action of a calculation device connected to the strain gauge by an electric wire.

Then, casting conditions such as a high-speed injection start point and a deceleration start point of the injection speed are set to appropriate conditions depending on the weight or amount of molten metal in this drawer.

As a result, if the high-speed injection start point is set to a desired point each time the weight or amount of molten metal to be poured changes, high-speed injection will start when the molten metal reaches the exit of the cavity 5. By performing the injection operation under optimal conditions, it is possible to reliably, easily and automatically obtain a cast product that is free of cavities and has good hot water flow.

〔Example〕

Next, the present invention will be explained in more detail with reference to embodiments shown in the drawings.

FIG. 4 illustrates one embodiment of the present invention.
In this embodiment, a load detector 20 consisting of a strain gauge is attached to the side surface of the arm 15 to which the arm 16 of the automatic water heater as shown in FIG. 3 is attached, at the position where the load is most likely to be applied. . The reason for attaching the strain gauge to the side of the arm 15 is to easily detect the weight of the molten metal in the strainer 16 and to be able to reliably and easily extract it as an electrical signal.

Then, a servo motor or
A drive device 22 consisting of a pulse motor or the like is attached, and a screw shaft 23 that is rotated in forward and reverse directions by this drive device 22 extends parallel to the axis of the cylinder 8 . A mounting seat 24 is screwed onto the screw shaft 23 so that it can move only in the axial direction of the screw shaft 23 without rotating.
A limit switch 12 for regulating the high-speed casting start position is fixed to and keeps its contact in sliding contact with the detection lever 11 at all times.

The load detector 20 measures the weight of the molten metal plus the weight of the molten metal 16 and the arm 15, but the molten metal is empty during the return stroke of the hot water supply process, so if the difference can be measured, the weight of the molten metal can be Can be measured.

The load detected by the load detector 20 enters the arithmetic unit 25 as an electrical signal, where it becomes a predetermined electrical output and is sent to the drive unit 22.

Here, the arithmetic device 25, the drive device 22,
The screw shaft 23 etc. are operated by the limit switch 12 for high-speed injection start command in response to a signal from the load detector 20.
This can be said to be a casting condition setting device that can control the position of and set a high-speed injection starting point, which is one of the casting conditions. Of course, the device for commanding the high-speed injection starting point is not limited to the limit switch 12, and other known position detection command devices such as a non-contact switch or a magnetic scale and a magnetic head can also be used. Furthermore, the injection speed can also be changed by controlling the point in time when the opening degree of the flow rate regulating valve is changed using a pulse motor or the like that is the driving device 22.

The calculation section 25 performs the following calculations.

First, the casting weight W of the target die-casting product and the diameter D of the sleeve of the die-casting machine (see FIG. 5) are input in advance. In general, it is said that it is best to start high-speed casting when the sleeve 6 is full of molten metal, so let the specific gravity of the molten metal be r, and calculate L from π/4D ² Lr=W. =4W/πD ² r is calculated and the position L of the chip 10 is stored.

At this time, if the load signal Wx sent from the load detector 20 is Wx = W ₀ (W + △W) (W ₀ is a tare weight, △W is the variation in the amount of hot water supplied), the molten metal is The movement ΔL of the high-speed casting start position to fill the sleeve 6 is determined by the following equation.

△L=4△W/πD ² r=4(Wx−W ₀ −W)/π
D ² r = 4 (Wx - W ₀ ) / πD ² r - L Since the tare weight W ₀ of Hishiyaku 16 is constant, if this is also input in advance, it will be reflected in the change in the amount of hot water detected by the detector. A corresponding output signal ΔL is obtained, which is amplified and supplied to the drive device 22,
By rotating the screw shaft 23 and moving the limit switch 12, it is possible to accurately adjust the high speed casting start position.

Since this embodiment is configured as described above,
High-speed casting always starts when the sleeve is full of molten metal, eliminating gas entrainment and molten metal jumping into the cavity, making it possible to obtain high-quality products, and ensuring that the high-speed casting section remains constant. Therefore, the filling time is constant and the quality of the product is stable. Further, the position of the limit switch for regulating the high-speed casting start position is automatically adjusted by simply inputting the casting weight and sleeve diameter, making the operation extremely simple.

Of course, the load and hot water supply amount detected by the load detector 20 are displayed on a gauge, and the operator reads the scale of this gauge with his eyes each time, and the operator operates the drive operation 22 by operating a lever or the like. It is also possible to adjust the high speed casting start position.

In addition, in the above example, the high speed casting start point is
In the above explanation, the molten metal has filled up in the sleeve 6, but depending on the shape and wall thickness of the cast product, this may occur after the sleeve 6 has been filled with molten metal. If it is judged that it is good when the tip 10 is slightly inserted, the position L of the tip 10 is adjusted.
is determined to be slightly smaller than the calculated value.

FIG. 6 explains another embodiment of the present invention, and this embodiment employs a structure in which the deceleration start position can also be automatically controlled.

That is, in this embodiment, the rod 9 of the cylinder 8 is formed hollow, and a through hole 9b is bored in the rod 9 near the piston 9a.

A hollow rod 30 for adjusting the deceleration position is inserted from the head side of the cylinder 8. This rod 30 slidably passes through the piston 9a and is inserted into the rod 9.
The through hole 30a is located near the rod 9 and midway inside the rod 9.
and a through hole 30b are bored. 35 is a check valve.

Further, the rod 30 and the base end of the screw shaft 23 are housed in a gear box 31. A worm wheel 32 is fixed to the screw shaft 23 in the gear box 31, and the rod 30 has a worm wheel 32 fixed to the screw shaft 23.
A worm wheel 33 rotatably supported on the shaft 1 is screwed together, and both worm wheels 32 and 33 are connected to a worm gear fixed to the output shaft of the drive device 2, 2, such as a pulse motor attached to the side of the gearbox or a nervo motor. It is meshed with 34.

Since this embodiment is configured as described above,
During casting, the hydraulic oil on the rod side of the cylinder 8 is pushed by the piston 9a and flows into the through hole 9b of the rod 9.
It enters into the rod 9 through the through hole 30b, and further into the rod 30 through the through hole 30b. Then, the hydraulic oil in the rod 30 passes through the check valve 35 in the rod 30 and passes through the through hole 30.
Enter the head side of cylinder 8 from a. In this state, the casting operation by the rod 9 progresses, and soon high-speed casting is started by the cooperation of the limit switch 12 and the detection lever 11, and the rod 9 moves forward at high speed.
Immediately before the end of high-speed casting, if the passage hole 30b of the rod 30 is blocked by the piston 9a, the hydraulic oil on the rod side cannot communicate with the head side of the cylinder 8, a mechanical brake is applied, and deceleration begins. be done.

Therefore, the amount of molten metal is detected by the load detector 20, calculated as described above by the calculation device 25, and the result is amplified and supplied to the drive device 22.
When the worm gear 34 is rotated, the limit switch 1 is activated via the worm wheel 32 and the screw shaft 23.
2 to change the high-speed casting start position of the cylinder 8, and the worm wheel 33
The peak pressure can also be reduced by moving the rod 30 through the cylinder 8 to change the deceleration start position of the cylinder 8.

Here, the arithmetic device 25, the drive device 22,
The worm gear 34, worm wheel 33, rod 30, etc. can be said to be a casting condition setting device that can control the start point of deceleration of the injection speed, which is one of the casting conditions, in accordance with the signal from the load detector 20. Of course, in the one shown in FIG.
It is also equipped with a casting condition setting device that can control the high speed injection starting point using signals from zero.

If the amount of hot water supplied changes, the solidification time of the molten metal will also change, but the mold clamping curing time can be adjusted accordingly, and if the amount of hot water supplied is abnormally high or low, this can be detected and an alarm signal sent. It is also possible to automatically stop the operation of the machine or change the cycle of the machine.

In addition to this, the casting conditions can be controlled by
Temperature of mold, sleeve, plunger tip, etc.
There is also control of the casting pressure and the timing of evacuation during vacuum die casting, but automatic control is possible by inputting set values of this information into the arithmetic unit.

〔effect〕

As is clear from the above description, according to the present invention, casting conditions can be set by signals from a load detector consisting of a strain gauge whose displacement changes depending on changes in the weight of molten metal in the mold. By installing a condition setting device, it is possible to not only reliably and easily detect changes in the weight of the cube, but also to set, for example, a high-speed injection start point or a deceleration start point of the injection speed, depending on the weight of the cube. You can set it at the optimal position, and also adjust the mold clamping curing time, the temperature of the mold, sleeve, plunger tip, etc., the casting pressure, and the timing of evacuation during vacuum die casting. Casting conditions can be set to optimal values.

According to the present invention, high-speed casting is performed at a desired point, such as when the sleeve is filled with molten metal, so there is no gas entrainment or molten metal jumping into the cavity, and a high-quality product is produced. Since the high-speed casting section is constant, the filling time is constant, the quality of the product is stable, and the high-speed pouring start position can be automatically adjusted, making the operation extremely simple. In addition, it is possible to automatically adjust the deceleration position of the injection operation and mold clamping curing time according to the amount of hot water supplied, issue an alarm when there is an abnormality in the amount of hot water supplied, and automatically adjust operations such as stopping the equipment. .

[Brief explanation of the drawing]

Fig. 1 A, B and Fig. 2 A, B are explanatory diagrams of inconveniences caused by differences in the amount of hot water supplied, respectively;
Fig. 3 is an explanatory diagram of an automatic water heater, Fig. 4 is a side view of one embodiment of the present invention, Fig. 5 A and B are explanatory diagrams of calculation elements, and Fig. 6 is an explanatory diagram of another embodiment of the invention. It is an explanatory diagram. 3...Fixed mold, 4...Movable mold, 5...Cavity, 6...Sleeve, 10...Chip, 12...Limit switch, 14, 22...Drive device, 15...Arm, 16...Hice, 20...Load detector, 25...
Arithmetic unit, 30...rod, 32, 33...worm wheel, 34...worm gear.

Claims (1)

[Scope of Claims] 1. A load detector consisting of a strain gauge whose displacement changes depending on changes in the weight of the molten metal in the reservoir is attached to the arm connecting the drive part of the automatic hot water supply device and the reservoir, and this load detection 1. A casting device equipped with an automatic hot water supply device, characterized in that it is equipped with a casting condition setting device that can set casting conditions based on signals from a casting device. 2. A casting device equipped with an automatic hot water supply device according to claim 1, characterized in that the casting condition setting device includes a device capable of controlling a high-speed injection starting point. 3. A casting device equipped with an automatic hot water supply device according to claim 1, characterized in that the casting condition setting device includes a device capable of controlling the start point of deceleration of the injection speed. 4. The automatic hot water supply device according to claim 1, which is equipped with a device configured to automatically control a high-speed injection start point and a deceleration start point of the injection speed as a casting condition setting device. Equipped with casting equipment.