JP2713736B2 - Degassing valve control device for die casting machine - Google Patents

Description

The present invention relates to a degassing valve control device in a cavity in a die casting machine, and particularly relates to a valve opening / closing timing corresponding to a high-speed actual injection start position of an injection plunger. And a control device for automatically adjusting automatically and optimally.

[Conventional technology]

In a conventional die casting machine, timing adjustment for opening and closing a gas release valve is performed by adjusting a relative position between a dog fixed to a piston rod of an injection plunger and a limit switch or the like.

[Problems to be solved by the invention]

However, the time required for the high-speed injection stroke of the injection plunger is extremely short, and this time is not much different from the operation delay time (including the relay operation time) of the solenoid valve for operating the gas release valve. Although the relative position adjustment between the dog and the limit switch is very important, it has been very difficult in practice. Therefore, there is a very high risk that the molten metal is ejected out of the mold when the closing of the gas release valve is delayed, and the quality of the die-cast product is deteriorated due to a shift in the closing timing of the valve. .

Therefore, an object of the present invention is to provide a degassing method for a die casting machine capable of closing a degassing valve at an optimal timing to avoid a risk of molten metal being ejected and forming a cast product having a specified quality. It is to provide a valve control device.

[Means for solving the problem]

Therefore, the present invention provides a degassing valve control device of a die casting machine for degassing a mold cavity at a predetermined position of an injection plunger, a position detector for detecting a stroke position of the injection plunger, The acceleration inflection point of the injection plunger is actually measured based on the detection signal, and the actually measured value is subjected to predetermined processing to obtain a high-speed injection actual start position, and a predetermined variable value is added or subtracted from the high-speed injection actual start position. An arithmetic unit for outputting a signal for closing the gas vent valve at the position where the injection valve is closed, and outputting a signal for opening the gas vent valve at the position where the injection plunger closes the hot water supply port; and an input for inputting predetermined data to the arithmetic unit. And a container.

Further, a sensor for detecting the blockage of the gas vent valve is provided, and the sensor detects the blockage of the valve, and the injection plunger stroke position at the moment when the valve is closed is measured to set the closed stroke position in advance. It is configured to perform control so as to match.

[Action]

According to the configuration of the present invention, the acceleration inflection point of the injection plunger is actually measured based on the detection signal of the position detector. The actually measured value is calculated by an arithmetic unit to obtain an average value of the actually measured values in each cycle obtained by performing a predetermined process, for example, a plurality of trial castings, and this average value is set as a high-speed injection actual start position. The arithmetic unit outputs a signal that closes the degassing valve at a position obtained by adding or subtracting a variable value calculated based on a delay time from the actual high-speed injection start position until the degassing valve operates and a variation in the amount of hot water supply. At the same time, the injection plunger outputs a signal to open the gas release valve at the position where the hot water supply port is closed. Also,
The input device is used when initializing a stroke value corresponding to the delay time.

In addition, while detecting the blockage of the valve by detecting the blockage of the degassing valve, the measured value of the valve closing stroke position is compared with a preset stroke position, and the values are automatically determined so that both values match. By performing the control, the closing timing adjustment of the valve is controlled with higher accuracy.

〔Example〕

Hereinafter, an embodiment of a gas vent valve control device for a die casting machine according to the present invention will be described with reference to the drawings.

FIG. 1 shows the overall configuration of the first embodiment. In this figure, on one side of a piston rod 2 of an injection cylinder device 1, a position detector for detecting the position of the piston rod 2, that is, the position of an injection plunger 5 arranged in an injection sleeve 4 in a mold device 3. 6 are provided. The position detector 6 is constituted by, for example, an absolute type linear encoder that generates a pulse. The position detector 6 is connected to an arithmetic unit 7 and receives a detection signal from the position detector 6.

The arithmetic unit 7 includes an input device 8 to which a position detection signal is input, a CPU 9 for performing predetermined arithmetic processing on data input to the input device 8, and an arithmetic result obtained by the CPU 9 or a predetermined set value. It is configured to include memories 10 and 11 for storing, and an output device 12 for outputting a predetermined signal according to a calculation result.

A data input device 13 is connected to the input device 8 of the arithmetic device 7, and the data input device 13 allows the injection plunger 5 to close the hot water supply port 14, a stroke Sc, and a high-speed injection start position stroke SL. An operation delay until valve closing of the gas release valve device 15 described later, a variable value M calculated and calculated based on a biscuit thickness B due to a variation in hot water supply amount, a high-speed injection stroke Sh of the injection plunger 5, and an injection plunger 5 The operation delay time Δt of the solenoid valve device for controlling the operation is input. The value M is represented by the following equation, where Δts is the operation delay time until the bush of the gas vent valve device is closed, ΔB is the variation of the biscuit thickness B, and C is the margin value.

M = ΔB + (VL × Δts) + C Here, VL is a low-speed injection speed, and a calculation program based on the above expression is incorporated in the calculation device 7 in advance.

Further, a display device 18 such as a CRT is connected to the arithmetic unit 7, and the display device 18 displays a movement stroke and an injection speed of the injection plunger 5, respectively. The arithmetic unit 7 has an interface
19 and said degassing valve device via amplifiers 20, 21
Each solenoid 24 of the solenoid valve 24 that operates 15
A excitation signal is supplied to A and 24B, and a low-speed injection / high-speed injection switching valve of the injection plunger 5 via the amplifiers 22 and 23.
An excitation signal is supplied to each of the solenoids 27A and 27B of a solenoid valve 27 for operating the solenoid 26.

The degassing valve device 15 is constituted by a vacuum valve device and communicates with a hydraulic / pneumatic cylinder 31 connected to a hydraulic / pneumatic source 30 via a solenoid valve 24 and a cavity 32 of the mold device 3. A gas outlet 35 is provided with a valve 34 facing the gas vent groove 33, and a vacuum device 36 is connected to the gas outlet 35.

In the actual injection, the degassing valve device 15 outputs a pulse from the position detector 6 corresponding to the stroke Sc,
When a signal is output from the output device 12 after counting by the arithmetic unit 7, the solenoid 24A of the solenoid valve 24 is excited via the interface 19 and the amplifier 21, and at this time, the valve 34 of the gas release valve device 15 The gas is opened by the operation of the pressure cylinder 31, and the gas in the cavity 32 is discharged from the discharge port 35 to the vacuum device 36.

In addition, S which is M before the high-speed injection actual stroke position SL1
The signal is output from the output device 32 at L2 and the interface
When the solenoid 24B of the solenoid valve 24 is excited via 19 and the amplifier 20, the hydraulic / pneumatic cylinder 30 is operated and the valve 34 of the gas vent valve device 15 is closed.

In FIG. 1, reference numeral 38 denotes an ON-OFF switch which operates in cooperation with the low-speed injection / high-speed injection switching valve 26, 39 denotes a gas accumulator connected to the piston accumulator 40, 41 denotes a hot water supply ladder, 42 Is a molten metal, and the symbol S
L2 is a stroke obtained by subtracting M from the stroke SL.

 Next, the operation of the present embodiment will be described with reference to FIG.

Prior to the start of the trial casting cycle, the stroke SL of the high-speed injection start position, the stroke Sc of the injection plunger 5 closing the hot water supply port 14, the delay until closing of the valve 34 in the degassing valve device 15, and the amount of hot water are supplied by the data input device 13. M, a high-speed injection stroke Sh that is determined in advance in accordance with the molding conditions specific to the mold,
And the operation delay time Δt of the solenoid valve 27 are input, and this is stored in the arithmetic unit 7.

After the above initial setting work is completed, the process shifts to the trial casting cycle and actual injection is performed. Here, the speed increasing inflection point is actually measured based on the position detection signal of the injection plunger 5 given from the position detector 6. I do. In the present embodiment, the point at which this speed-up inflection point increases by VL (1 + 0.1) by 10% or more with respect to the injection speed VL of the injection plunger 5 in the low-speed injection stroke is defined as the inflection point. . The inflection point is calculated by the arithmetic unit 7, and the stroke position of the point is determined as the high-speed injection actual start position, and the stroke is stored in the memory 10 as SL1. At the same time, the stroke difference from the high-speed injection actual start position to the stroke S indicating the filling completion time is the high-speed injection actual stroke S.
h1 and this is stored in the memory 10.

The actual injection continues a plurality of times, and when the high-speed injection actual stroke Sh1 obtained for each injection cycle reaches a predetermined sampling number n, the CPU 9 reads the high-speed injection actual stroke Sh1 sequentially stored in the memory 10 and reads out the actual injection. The average value Sh2
Is calculated, and this average value Sh2 is compared with the preset value Sh of the high-speed injection stroke input in advance. Here, the average value Sh
If the value 2 does not match the set value Sh, the arithmetic unit 7
The time at which the operation signal of the solenoid valve 27 is output is corrected by ± based on ΔSh2, and the average value Sh2 and the set value S
Control is performed so that h matches. By this processing, a high-speed injection actual start position is obtained.

After matching the average value Sh2 with the set value Sh in the above process, a signal for operating the solenoid 24B of the solenoid valve 24 with S-Sh1-M and closing the valve 35 of the degassing valve device 15 is output. You.

According to the first embodiment, the acceleration inflection point of the injection plunger 5 is actually measured based on the detection signal of the position detector 6, and the high-speed injection actual start position is obtained by the arithmetic unit 7, and the high-speed injection actual start position is obtained. A stroke corresponding to a predetermined variable value M from the actual injection start position, that is, a value obtained based on a variation ΔB of the biscuit thickness B due to a variation in the operation delay Δts from when the valve 34 of the degassing valve device 15 is closed and a variation in the amount of hot water. Since the solenoid 24B is excited at the position to adjust the timing of closing the valve 34 of the degassing valve device 15, the valve opening / closing control can be realized with high accuracy according to the actual casting conditions. There is an effect that it is possible to prevent the molten metal from being spouted.

Further, since the timing adjustment can be automatically performed by the arithmetic unit 7, there is no need for any mechanical adjustment work as in the related art, and the adjustment work can be performed in an extremely short time.

Further, when determining the high-speed injection actual stroke position, the control is configured so that the high-speed injection actual stroke obtained based on the actual casting is equal to the set value, so that the quality characteristic of the die cast product is significantly affected. A high-speed injection stroke can be adjusted with high precision, and a die-cast product having a certain quality can be provided.

Next, a second embodiment of the present invention will be described with reference to FIGS. The same reference numerals are used for the same or equivalent components as those of the first embodiment,
Description is omitted or simplified.

In the second embodiment, a sensor 43 for detecting blockage of the valve 34 in the degassing valve device 15 is connected to the valve 34.
The injection plunger stroke position at the moment when the valve 34 closes is actually measured for each test casting cycle, and the average value of the measured values is controlled so as to match a predetermined set value. Things.

The sensor 43 includes a magnetic body 44 fixed to a piston rod constituting the degassing valve device 15, and a detection unit 45 disposed at a position close to the magnetic body 44 via a fixing unit (not shown). It is configured. The detection unit
Numeral 45 is configured to transmit a closing signal pulse to the input device 8 of the arithmetic unit 7 when the valve 34 is completely closed.

In the above configuration, the variable value M determined by the delay until closing of the valve 34 in the degassing valve device 15 and the variation of the hot water supply amount is determined by the high-speed injection start position as shown in FIG. _SL (see FIG. 4 (A))
Are set on the plus side and the minus side, respectively. Further, the low-speed injection stroke S _L ±
When a voltage is applied to the solenoid 24B of the solenoid valve 24 at the stroke position where M = SL3, the valve 34 is closed. Further, when the valve 34 is completely closed, the sensor 43 detects this, and generates a closing signal pulse as shown in FIG.
This is output to the input device of the arithmetic unit 7. In this case, the stroke of the position where the closing signal pulse is generated is SVC, and SVC-S _L = N is input to the arithmetic unit 7 from the input device 13 in advance as the optimum closing position of the valve 34.

In FIG. 4 (C), reference symbol SVC3 indicates an actual measured stroke position from the starting point of the injection plunger 5, and N3
Indicates actual measured values of the closing signal stroke position of the valve 34.

Hereinafter, the operation of the second embodiment will be described with reference to FIG.

In the initial setting operation, the input from the input device 13 is performed in substantially the same manner as in the first embodiment, but in the second embodiment, the set value N and the ± corrected value of the set value M are further set. ΔM is additionally input. At this time, the minimum unit of ΔM is set to, for example, 0.5 mm.

After the above initial setting work is completed, the process shifts to the trial casting cycle and actual injection is performed. First, ΔSh2 is set until the average value Sh2 of the high-speed injection actual stroke Sh1 matches the set value Sh, as in the first embodiment. The high-speed injection actual start position is obtained by the ± correction control, and then ± correction is performed for the set value M by ΔM.

For that S _L, outputs an operation signal of the solenoid 24B in the stroke position of the S _L ± M, the sensor 43 is determined as the measured value N3 strokes when emitted occlusion signal pulse to detect a blockage of the valve 34. When the actual measured value N3 reaches the predetermined number n of samplings by repeating such a cycle a plurality of times, the average value N4 is calculated, and the average value N4 is calculated.
Is compared with the set value N or not, and the set value M is corrected by ± M by ± M until both values match,
All processes end on condition that they match.

Therefore, according to the second embodiment, in addition to the effect of the first embodiment, the stroke of the closing signal pulse of the valve 34 is obtained by actual measurement when adjusting the opening and closing of the degassing valve device 15. The average value N4, which is a value obtained by sampling control, is compared with the set value N, and if necessary, the set value M is corrected stepwise by .DELTA.M in a stepwise manner. The operation delay time of the solenoid valve 24B for operating the valve 15 can be grasped elastically and accurately according to casting conditions and the like.
The effect that the opening / closing control can be performed with higher accuracy can be added.

Further, since the means for performing the timing adjustment uses a single arithmetic unit, there is no possibility that the entire apparatus will become large.

The configuration of the position detector 6 is not limited to that of the above-described embodiment, and a known detector capable of detecting the stroke position of the injection plunger 5 can be applied.

〔The invention's effect〕

As described above, according to the present invention, it is possible to operate the degassing valve at an optimal timing to avoid the risk of molten metal jetting and to form a die-cast product having a constant quality characteristic. There is an effect that a gas vent valve control device for a machine can be provided.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing the overall configuration of a first embodiment of the present invention, FIG. 2 is a flowchart showing the operation of the first embodiment,
FIG. 3 is a view similar to FIG. 1 showing the overall configuration of the second embodiment of the present invention, and FIG. 4 is a line showing the moving speed of the injection plunger, the applied voltage of the solenoid, and the closing signal pulse in the second embodiment. FIG. 5 and FIG. 5 are flow charts showing the operation of the second embodiment. DESCRIPTION OF SYMBOLS 1 ... Injection cylinder device, 3 ... Mold device, 5 ... Injection plunger, 6 ... Position detector, 7 ... Computing device, 13 ...
… Data input device, 15… degassing valve device, 24… solenoid valve, 26… low-speed injection / high-speed injection switching valve, 27… solenoid valve, 32… cavity, 34…
…valve.

Claims (2)

(57) [Claims] 1. A degassing valve control device of a die casting machine for degassing a mold cavity at a predetermined position of an injection plunger, a position detector for detecting a stroke position of the injection plunger, and detection of the position detector. The acceleration inflection point of the injection plunger was actually measured based on the signal, and the actually measured value was subjected to predetermined processing to obtain a high-speed injection actual start position, and a predetermined variable value was added or subtracted from the high-speed injection actual start position. An arithmetic unit for outputting a signal for closing the vent valve at the position and outputting a signal for opening the vent valve at the position where the injection plunger closes the hot water supply port; and an input device for inputting predetermined data to the arithmetic unit A degassing valve control device for a die casting machine, comprising: 2. The apparatus according to claim 1, further comprising a sensor for detecting a blockage of said degassing valve, wherein said sensor detects the blockage of said valve and measures and sets an injection plunger stroke position at the moment when said valve is closed. A degassing valve control device for a die casting machine, which controls the injection plunger stroke position at the moment the closed valve is closed.