JP6909714B2 - Squeeze pin controller and die casting machine with it - Google Patents

Description

The present invention relates to a squeeze pin control device and a die casting machine having the squeeze pin control device.

Reference 1 discloses a control device for a pressure pin that locally pressurizes the molten metal filled in the cavity of the mold. This control device has a pressure booster that supplies hydraulic oil to a cylinder provided with a pressure pin at the tip of the rod. The pressure booster consists of a single rod cylinder and has a pressure boosting piston. The control device detects the position of the pressure boosting piston by a sensor provided in the pressure booster, and confirms whether or not the rod of the cylinder has retracted based on the position of the pressure boosting piston.

Patent No. 4520007

In the control device described above, each of the cylinder and the booster is returned to the origin at the end of the operation to prepare for the next operation. Therefore, the pressure booster and the cylinder are connected in series during the pressurization operation, and the pressure booster and the cylinder are connected in parallel during the origin return operation. However, in the above-mentioned control device, a plurality of on-off valves for switching the circuit are required, and the circuit configuration is complicated.

Therefore, an object of the present invention is to provide a squeeze pin control device having a simple circuit configuration and a die casting machine having the squeeze pin control device.

In order to achieve the above object, the squeeze pin control device according to one aspect of the present invention includes a pressure cylinder containing a pressure piston for advancing and retreating the squeeze pin.
A detection cylinder containing a detection piston and
A position sensor that detects the position of the detection piston and
It has A port, B port, P port and T port, and has a parallel connection position that communicates A port and T port and communicates B port and P port, and communicates A port and P port and B port. A connection switching valve that has at least a communication position that disconnects the T port and the T port.
It has A port, B port, P port and T port, and has a backward flow position that communicates A port and P port and communicates between B port and T port, and communicates between A port and T port and B port. A directional control valve that has at least a forward flow position that communicates with the P port,
A first flow path connecting the rear oil chamber of the pressure cylinder and the B port of the direction switching valve,
A second flow path connecting the front oil chamber of the pressure cylinder and the P port of the connection switching valve, and
A third flow path connecting the rear oil chamber of the detection cylinder and the A port of the connection switching valve, and
A fourth flow path connecting the front oil chamber of the detection cylinder, the B port of the connection switching valve, and the A port of the directional switching valve,
Has a control unit,
The P port of the directional control valve is connected to a pump that supplies hydraulic oil.
The T port of the direction switching valve and the T port of the connection switching valve are connected to the tank from which the hydraulic oil is discharged.
The control unit
(1) When the pressurizing piston is advanced, the connection switching valve is controlled to be in the series connection position and the direction switching valve is controlled to be in the forward flow position.
(2) When the pressurizing piston is retracted, the connection switching valve is controlled to be in the series connection position and the direction switching valve is controlled to be in the retracting flow position.
(3) When the pressurizing piston and the detection piston are returned to the origin, the connection switching valve is controlled to be in the parallel connection position and the direction switching valve is controlled to be in the backward flow position.
(4) The operation state of the pressurizing piston is detected based on the position of the detection piston detected by the position sensor.

In order to achieve the above object, the squeeze pin control device according to another aspect of the present invention includes a pressure cylinder containing a pressure piston for advancing and retreating the squeeze pin.
A detection cylinder containing a detection piston and
A position sensor that detects the position of the detection piston and
It has A port, B port, P port and T port, and has a parallel connection position that communicates A port and T port and communicates B port and P port, and communicates A port and P port and B port. A connection switching valve that has at least a communication position that disconnects the T port and the T port.
It has A port, B port, P port and T port, and has a backward flow position that communicates A port and P port and communicates between B port and T port, and communicates between A port and T port and B port. A directional control valve that has at least a forward flow position that communicates with the P port,
A first flow path connecting the rear oil chamber of the detection cylinder and the B port of the direction switching valve,
A second flow path connecting the front oil chamber of the detection cylinder and the P port of the connection switching valve, and
A third flow path connecting the rear oil chamber of the pressure cylinder and the A port of the connection switching valve,
A fourth flow path connecting the front oil chamber of the pressurizing cylinder, the B port of the connection switching valve, and the A port of the directional switching valve,
Has a control unit,
The P port of the directional control valve is connected to a pump that supplies hydraulic oil.
The T port of the direction switching valve and the T port of the connection switching valve are connected to the tank from which the hydraulic oil is discharged.
The control unit
(1) When the pressurizing piston is advanced, the connection switching valve is controlled to be in the series connection position and the direction switching valve is controlled to be in the forward flow position.
(2) When the pressurizing piston is retracted, the connection switching valve is controlled to be in the series connection position and the direction switching valve is controlled to be in the retracting flow position.
(3) When the pressurizing piston and the detection piston are returned to the origin, the connection switching valve is controlled to be in the parallel connection position and the direction switching valve is controlled to be in the backward flow position.
(4) The operation state of the pressurizing piston is detected based on the position of the detection piston detected by the position sensor.

In the present invention, the direction switching valve has a flow rate adjusting unit for adjusting the flow rate of the hydraulic oil, and the control unit detects the advancing speed of the pressure piston as an operating state of the pressure piston. It is preferable to feedback-control the flow rate adjusting unit of the direction switching valve so that the advancing speed approaches the set speed.

In the present invention, it is preferable that the control unit changes the set speed based on the past forward end position of the pressure piston.

In the present invention, the control unit determines whether or not the forward speed of the pressurizing piston is within the normal range set for each time or position, and notifies an abnormality when it is not within the normal range. Is preferable.

In order to achieve the above object, the die casting machine according to another aspect of the present invention includes a mold clamping device for opening and closing a mold and an injection for injecting molten metal into a cavity of the mold closed in the mold clamping device. A die casting machine including a device and a squeeze pin control device for moving a squeeze pin back and forth into the cavity of the mold, wherein the squeeze pin control device is composed of the squeeze pin control device. ..

According to the present invention, the pressurizing cylinder and the detection cylinder are switched between series connection and parallel connection by the connection switching valve and the direction switching valve having four ports, respectively, and the flow direction of the hydraulic oil is changed in the forward direction (forward) and in the reverse direction. You can switch to the direction (backward). Therefore, it is possible to realize a configuration in which the position of the pressure piston can be detected with a simple circuit.

It is sectional drawing of the main part of the die casting machine which concerns on one Embodiment of this invention. FIG. 5 is a cross-sectional view illustrating a state in which a squeeze pin is inserted into a cavity of a mold in the die casting machine of FIG. It is a circuit diagram explaining the operation of the squeeze pin control device of the die casting machine of FIG. 1 (preparatory operation). It is a circuit diagram explaining the operation of the squeeze pin control device of the die casting machine of FIG. 1 (forward operation). It is a circuit diagram explaining the operation of the squeeze pin control device of the die casting machine of FIG. 1 (backward operation). It is a circuit diagram explaining the operation of the squeeze pin control device of the die casting machine of FIG. 1 (origin return operation). It is a circuit diagram explaining the operation of the modification of the squeeze pin control device of the die casting machine of FIG. 1 (preparatory operation). It is a circuit diagram explaining the operation of the modification of the squeeze pin control device of the die casting machine of FIG. 1 (forward operation). It is a circuit diagram explaining the operation of the modification of the squeeze pin control device of the die casting machine of FIG. 1 (backward operation). It is a circuit diagram explaining the operation of the modification of the squeeze pin control device of the die casting machine of FIG. 1 (origin return operation).

Hereinafter, the die casting machine according to the embodiment of the present invention will be described with reference to FIGS. 1 to 3.

FIG. 1 is a cross-sectional view of a main part of a die casting machine according to an embodiment of the present invention. FIG. 2 is a partial cross-sectional view illustrating how the squeeze pin is inserted into the cavity of the mold. FIG. 2 (a) shows before insertion, and FIG. 2 (b) shows after insertion. 3 to 6 are circuit diagrams for explaining the operations of the squeeze pin control device (preparatory operation, forward operation, backward operation, and origin return operation).

The die casting machine 1 of the present embodiment includes a mold clamping device 10, an injection device 20, a squeeze pin control device 30, and a control unit 90.

The mold clamping device 10 has a fixed die plate 11 to which the fixed mold K1 is attached and a moving die plate 12 to which the moving mold K2 is attached. The fixed die plate 11 has a cylindrical injection sleeve 13. The injection sleeve 13 has a hot water supply port 14 formed at the upper portion, and the molten metal M is poured by a ladle (not shown). The mold clamping device 10 closes and opens the fixed mold K1 and the moving mold K2. A cavity C is formed inside the fixed mold K1 and the moving mold K2 that are closed.

The injection device 20 includes an injection piston 22 having a plunger tip 21 attached to the tip thereof, and an injection cylinder (not shown) for advancing and retreating the injection piston 22. The plunger tip 21 is arranged in the injection sleeve 13. The injection device 20 injects and fills the molten metal M in the injection sleeve 13 into the cavity C by advancing the injection piston 22.

The squeeze pin control device 30 includes a pressure cylinder 40, a detection cylinder 50, a connection switching valve 60, and a direction switching valve 70.

The pressure cylinder 40 is arranged inside the fixed mold K1. The pressure cylinder 40 houses the pressure piston 41. A squeeze pin 42 is fixed to the pressure piston 41. When the pressure piston 41 is moved forward and backward by the hydraulic oil supplied to the pressure cylinder 40, the squeeze pin 42 is also moved forward and backward. The tip 42a of the squeeze pin 42 is moved between the origin O (O) and the forward end position L and is inserted into and removed from the cavity C.

The detection cylinder 50 houses the detection piston 51. The detection cylinder 50 is provided with a position sensor 52 including a linear encoder or the like that detects the position of the detection piston 51.

The connection switching valve 60 is a solenoid valve that switches the valve body position by a solenoid. The connection switching valve 60 has four ports, an A port, a B port, a P port, and a T port. The connection switching valve 60 has a valve body position of a parallel connection position in which the A port and the T port communicate with each other and the B port and the P port in communication, and a B port and the T port in which the A port and the P port communicate with each other. Has a series connection position to disconnect. The connection switching valve 60 connects the pressurizing cylinder 40 and the detection cylinder 50 in parallel and in series by switching the valve body position. The connection switching valve 60 may have a neutral position in which all ports are disconnected, and may have at least a parallel connection position and a series connection position.

The direction switching valve 70 is a solenoid valve that switches the valve body position by a solenoid. The directional control valve 70 has four ports, an A port, a B port, a P port, and a T port. As the valve body position, the direction switching valve 70 communicates with the A port and the P port and the B port and the T port with each other, and the A port and the T port communicate with each other and the B port and the P port. It has a forward flow position that communicates with and a neutral position that cuts between all ports. The direction switching valve 70 switches the flow direction of the hydraulic oil between the forward direction (squeeze pin forward) and the reverse direction (squeeze pin backward) by switching the valve body position. The directional control valve 70 may have at least a backward flow position and a forward flow position.

The direction switching valve 70 has a flow rate adjusting unit that adjusts the flow rate of the hydraulic oil flowing inside according to the input current.

The rear oil chamber 45 of the pressurizing cylinder 40 and the B port of the direction switching valve 70 are connected by the first flow path R1. The front oil chamber 46 of the pressurizing cylinder 40 and the P port of the connection switching valve 60 are connected by a second flow path R2. The rear oil chamber 55 of the detection cylinder 50 and the A port of the connection switching valve 60 are connected by a third flow path R3. The front oil chamber 56 of the detection cylinder 50, the B port of the connection switching valve 60, and the A port of the direction switching valve 70 are connected by the fourth flow path R4. A pressure sensor 81 for detecting the pressure of the hydraulic oil in the rear oil chamber 45 of the pressure cylinder 40 is provided in the first flow path R1.

The P port of the directional control valve 70 is connected to the pump 84 driven by the motor 83 via the pressure reducing valve 82. The pressure reducing valve 82 limits the pressure of the hydraulic oil flowing through the P port of the directional control valve 70 according to the input current. The T port of the connection switching valve 60 and the T port of the directional switching valve 70 are connected to the tank 85 from which the hydraulic oil is discharged.

The die casting machine 1 has a control unit 90 that controls the overall operation. The control unit 90 has, for example, a microcomputer for an embedded device having a CPU, ROM, RAM, EEPROM, various I / O interfaces, and the like. The control unit 90 executes a mold closing process, a hot water pouring process, an injection process, a pressure increasing process (pressure holding / cooling process), a mold opening process, a product extrusion process, and the like by controlling various drive units of each device. do.

In a series of operations for molding a product, the die casting machine 1 first moves the moving die plate 12 to mold the fixed mold K1 and the moving mold K2 (mold closing step). Next, the molten metal M is injected into the injection sleeve 13 of the fixed die plate 11 (pouring step). Then, the injection piston 22 is advanced, and the molten metal M in the injection sleeve 13 is injected and filled into the cavity C by the plunger tip 21 (injection step). Further, the molten metal M is pressed by the plunger tip 21 and pushed into the cavity C (pressure increasing step). After that, the mold is opened (mold opening process) and the product is extruded from the cavity (product extrusion process). Further, the die casting machine 1 locally pressurizes with a squeeze pin in parallel with the pressure increasing step (local pressurizing step).

In the present embodiment, the control unit 90 is connected to the connection switching valve 60, the direction switching valve 70, the pressure reducing valve 82, and the motor 83 of the squeeze pin control device 30, and controls by transmitting a control signal to these. .. The control unit 90 is connected to the position sensor 52 and the pressure sensor 81, receives detection signals from these, and based on the detection signals, the position and speed of the detection piston, and the pressure in the rear oil chamber 45 of the pressurizing cylinder 40. Is detected.

Next, an example of the local pressurization process (local pressurization step) according to the present invention in the control unit 90 of the die casting machine 1 of the present embodiment described above will be described with reference to Table 1 and FIGS. 3 to 6. In each figure, the thick gray arrows schematically indicate the flow of hydraulic oil. In the initial state of the local pressurization process, the tip 42a of the squeeze pin 42 is at the origin O.

(1) As shown in FIG. 3, before the injection process is completed, as a preparatory operation, the control unit 90 sets the valve body position of the connection switching valve 60 to the parallel connection position and the valve body of the direction switching valve 70. Set the position to the neutral position. Then, the control unit 90 sets the upper limit pressure of the hydraulic oil flowing to the P port of the direction switching valve 70 in the pressure reducing valve 82. The control unit 90 starts the operation of the hydraulic oil motor 83 to drive the pump 84. As a result, the hydraulic oil flows from the tank 85 through the pressure reducing valve 82 to the P port of the directional control valve 70, but the circuit is cut off and the flow is restricted.

(2) As shown in FIG. 4, when the injection process is completed and the pressure boosting process is started, as a forward operation, the control unit 90 sets the valve body position of the connection switching valve 60 to the series connection position and switches the direction. The valve body position of the valve 70 is set to the forward flow position.

As a result, the hydraulic oil flows into the rear oil chamber 45 of the pressurizing cylinder 40 through the P port and B port of the direction switching valve 70 and the first flow path R1, and the pressurizing piston 41 advances (to the left in the figure). Moving. As the pressure piston 41 advances, the hydraulic oil in the front oil chamber 46 of the pressure cylinder 40 passes through the second flow path R2, the P port and A port of the connection switching valve 60, and the third flow path R3, and the detection cylinder 50. It flows into the rear oil chamber 55 and the detection piston 51 advances. By advancing the detection piston 51, the hydraulic oil in the front oil chamber 56 of the detection cylinder 50 is finally discharged to the tank 85 through the fourth flow path R4 and the A port and the T port of the direction switching valve 70. Due to the flow of hydraulic oil, the pressure piston 41 moves from the origin O to the forward end position L and holds that state for a predetermined time.

At this time, the control unit 90 detects the forward speed of the pressurizing piston 41 as an operating state based on the detection signal of the position sensor 52, and the flow rate adjusting unit of the direction switching valve 70 so that the forward speed approaches the set speed. Feedback control (PID control) is performed to adjust the flow rate of hydraulic oil flowing through the direction switching valve 70. In the present embodiment, the set speed is set for each position of the pressure piston 41. Alternatively, the set speed may be set for each time from the start of advancing the pressure piston 41. Then, the control unit 90 sets the range of ± 10% around the set speed as the normal range, determines whether or not the forward speed of the pressurizing piston 41 is within the normal range for each position or time, and determines whether or not the forward speed is within the normal range. When it is not inside, a buzzer or the like sounds an alarm to notify the abnormality. The control unit 90 may notify the abnormality when it detects a case where the forward speed of the pressure piston 41 is not within the normal range a plurality of times.

Alternatively, the control unit 90 detects the pressure in the rear oil chamber of the pressure cylinder 40 based on the detection signal of the pressure sensor 81, and similarly to the forward speed, the direction switching valve 70 so that this pressure approaches the set pressure. The flow rate adjusting unit may be feedback-controlled to adjust the flow rate of the hydraulic oil flowing through the direction switching valve 70. The set pressure may be set for each position of the pressurizing piston 41 or for each time from the start of advancement of the pressurizing piston 41, similarly to the set speed. Then, the control unit 90 sets the range of ± 10% around the set pressure as the normal range, and determines whether or not the pressure in the rear oil chamber 45 of the pressure piston 41 is within the normal range for each position or time. However, when it is not within the normal range, an abnormality may be notified by sounding an alarm by a buzzer or the like.

(3) As shown in FIG. 5, when the forward operation is completed, as a backward operation, the control unit 90 keeps the valve body position of the connection switching valve 60 at the series connection position and changes the valve body position of the directional switching valve 70. Set to the backward flow position.

As a result, the hydraulic oil flows into the front oil chamber 56 of the detection cylinder 50 through the P port and A port of the direction switching valve 70 and the fourth flow path R4, and the detection piston 51 retracts (moves to the right in the figure). do. Due to the retreat of the detection piston 51, the hydraulic oil in the rear oil chamber 55 of the detection cylinder 50 passes through the third flow path R3, the A port and P port of the connection switching valve 60, and the second flow path R2 of the pressure cylinder 40. It flows into the front oil chamber 46, and the pressure piston 41 retracts. Due to the retreat of the pressurizing piston 41, the hydraulic oil in the rear oil chamber 45 of the pressurizing cylinder 40 is finally discharged to the tank 85 through the first flow path R1 and the B port and the T port of the directional control valve 70. .. Due to the flow of hydraulic oil, the pressure piston 41 moves from the forward end position L toward the origin O. At this time, the pressure piston 41 may not accurately return to the origin O due to a difference in structure between the pressure cylinder 40 and the detection cylinder 50, leakage of hydraulic oil, or the like, and may stay in the vicinity of the origin O'.

Further, the control unit 90 detects the position of the pressurizing piston 41 based on the detection signal of the position sensor 52, and determines whether or not the pressurizing piston 41 is retracted. When the control unit 90 determines that the pressure piston 41 is not retracting, the control unit 90 notifies the abnormality.

(4) As shown in FIG. 6, when the retracting operation is completed, the control unit 90 sets the valve body position of the connection switching valve 60 to the parallel connection position and the valve body position of the direction switching valve 70 as the origin return operation. Leave in the backward flow position.

As a result, the hydraulic oil flows into the front oil chamber 46 of the pressure cylinder 40 and the front oil chamber 56 of the detection cylinder 50 through the P port and A port of the direction switching valve 70 and the fourth flow path R4, and the pressure piston 41 and the detection piston 51 retract. Further, due to the retreat of the pressurizing piston 41, the hydraulic oil in the rear oil chamber 45 of the pressurizing cylinder 40 is finally discharged to the tank 85 through the first flow path R1 and the B port and the T port of the direction switching valve 70. Will be done. Further, due to the retreat of the detection piston 51, the hydraulic oil in the rear oil chamber 55 of the detection cylinder 50 is finally discharged to the tank 85 through the third flow path R3, the A port and the T port of the connection switching valve 60. .. Due to the flow of hydraulic oil, the pressure piston 41 and the detection piston 51 retract until they hit a stopper (not shown), and the position of the pressure piston 41 returns to the origin O. Similarly, the position of the detection piston 51 also returns to the origin.

Table 1 shows the relationship between each operation in the local pressurization process and the valve body positions of the connection switching valve 60 and the direction switching valve 70.

From the above, according to the die casting machine 1 of the present embodiment, the squeeze pin control device 30 switches the pressurizing cylinder 40 and the detection cylinder 50 to series connection and parallel connection by the connection switching valve 60 and the direction switching valve 70. The flow direction of the hydraulic oil can be switched between the forward direction (forward) and the reverse direction (backward). Therefore, it is possible to realize a configuration in which the position of the pressurizing piston 41 can be detected by a simple circuit having only two switching valves.

Further, the direction switching valve 70 has a flow rate adjusting unit for adjusting the flow rate of the hydraulic oil, and the control unit 90 detects the advancing speed of the pressurizing piston 41 and changes the direction so that the advancing speed approaches the set speed. The flow rate adjusting unit of the valve 70 is feedback-controlled. Therefore, the forward speed can be brought closer to the set speed more effectively, and the squeeze pin can be controlled accurately.

Further, the control unit 90 determines whether or not the advancing speed of the pressurizing piston 41 is within the normal range set for each time or position, and notifies the abnormality when it is not within the normal range. Therefore, it is possible to detect an operation abnormality of the device and a product defect caused by the operation abnormality at an early stage.

In the die casting machine 1 of the above-described embodiment, when the pressurizing cylinder 40 and the detection cylinder 50 are connected in series, a squeeze pin connecting the front oil chamber 46 of the pressurizing cylinder 40 and the rear oil chamber 55 of the detection cylinder 50. It was configured to have a control device 30. However, the configuration is not limited to this. For example, as shown in FIGS. 7 to 10, when the pressure cylinder 40 and the detection cylinder 50 are connected in series, the front oil chamber 56 of the detection cylinder 50 and the rear oil chamber 45 of the pressure cylinder 40 are connected. It may be configured to have a squeeze pin control device 30A. The squeeze pin control device 30A has the same configuration as the squeeze pin control device 30 except that the pressure cylinder 40 and the detection cylinder 50 are replaced and the pressure sensor 81 is provided in the third flow path R3. Further, since the squeeze pin control device 30A performs the operations (1) to (4) above in the local pressurization process like the squeeze pin control device 30, detailed description thereof will be omitted. The die casting machine having the squeeze pin control device 30A also has the same effect as the die casting machine 1 of the above-described embodiment.

Further, in the die casting machine 1 of the above-described embodiment, the control unit 90 may change the set speed of the pressure piston 41 based on the past forward end position L of the pressure piston 41. The forward end position L of the pressure piston 41 varies depending on various conditions (season, time zone, elapsed time from device start, fluctuation of pump discharge amount and valve flow rate over time, clogging of hydraulic oil filter, etc.). Sometimes. Therefore, for example, the control unit 90 stores the forward end position L for one to several times in the past, and its fluctuation tendency (whether the forward end position L tends to approach the origin O or moves away from it). Is detected. Then, the next forward end position L is predicted from the fluctuation tendency, and the set speed or the set pressure is adjusted so that the pressurizing piston 41 stops at this forward end position L. For example, the set speed set for each position of the pressurizing piston 41 is increased or decreased as a whole, the set speed is increased or decreased only in a part section, and the ratio between the acceleration section and the constant speed section is changed. By doing so, it is possible to suppress the variation in the forward end position L. Further, the forward end position L may be stored for a long period of time, the fluctuation tendency may be learned, and the set speed or the set pressure may be adjusted based on the learning result.

Further, the die casting machine 1 of the above-described embodiment performs a plurality of preliminary molding operations (discard molding operation) for stabilizing the operation immediately after the machine is started. In this preliminary molding operation, the control unit 90 gradually changes the forward end position L of the squeeze pin 42 according to the length of the machine stop time immediately before the machine starts, so that the pressurizing effect of the squeeze pin 42 May be gradually increased. Specifically, the longer the machine stop time is, the smaller the change amount of the forward end position L is, and the shorter the machine stop time is, the larger the change amount of the forward end position L is. By doing so, the operation can be stabilized more effectively, and the occurrence of defective products can be suppressed.

Although embodiments of the present invention have been described above, the present invention is not limited to these examples. As long as the gist of the present invention is provided, a person skilled in the art appropriately adding, deleting, or changing the design of the above-described embodiment, or combining the features of the embodiment as appropriate is also present. Included in the scope of the invention.

1 ... Die casting machine, 10 ... Mold clamping device, 11 ... Fixed die plate, 12 ... Moving die plate, 13 ... Injection sleeve, 14 ... Hot water supply port, 20 ... Injection device, 21 ... Plunger tip, 22 ... Injection piston, 30, 30A ... Squeeze pin control device, 40 ... Pressurized cylinder, 41 ... Pressurized piston, 42 ... Squeeze pin, 42a ... Squeeze pin tip, 45 ... Pressurized cylinder rear oil chamber, 46 ... Pressurized cylinder front oil chamber , 50 ... detection cylinder, 51 ... detection piston, 52 ... position sensor, 55 ... detection cylinder rear oil chamber, 56 ... detection cylinder front oil chamber, 60 ... connection switching valve, 70 ... direction switching valve, 81 ... pressure sensor , 82 ... Pressure reducing valve, 83 ... Motor, 84 ... Pump, 85 ... Tank, 90 ... Control unit, K1 ... Fixed mold, K2 ... Moving mold, C ... Cavity, M ... Metal molten metal, R1 ... First flow path , R2 ... 2nd flow path, R3 ... 3rd flow path, R4 ... 4th flow path, O ... origin of pressurizing piston, L ... forward end position of pressurizing piston

Claims (6)

A pressure cylinder containing a pressure piston that advances and retreats the squeeze pin,
A detection cylinder containing a detection piston and
A position sensor that detects the position of the detection piston and
It has A port, B port, P port and T port, and has a parallel connection position that communicates A port and T port and communicates B port and P port, and communicates A port and P port and B port. A connection switching valve that has at least a communication position that disconnects the T port and the T port.
It has A port, B port, P port and T port, and has a backward flow position that communicates A port and P port and communicates between B port and T port, and communicates between A port and T port and B port. A directional control valve that has at least a forward flow position that communicates with the P port,
A first flow path connecting the rear oil chamber of the pressure cylinder and the B port of the direction switching valve,
A second flow path connecting the front oil chamber of the pressure cylinder and the P port of the connection switching valve, and
A third flow path connecting the rear oil chamber of the detection cylinder and the A port of the connection switching valve, and
A fourth flow path connecting the front oil chamber of the detection cylinder, the B port of the connection switching valve, and the A port of the directional switching valve,
Has a control unit,
The P port of the directional control valve is connected to a pump that supplies hydraulic oil.
The T port of the direction switching valve and the T port of the connection switching valve are connected to the tank from which the hydraulic oil is discharged.
The control unit
(1) When the pressurizing piston is advanced, the connection switching valve is controlled to be in the series connection position and the direction switching valve is controlled to be in the forward flow position.
(2) When the pressurizing piston is retracted, the connection switching valve is controlled to be in the series connection position and the direction switching valve is controlled to be in the retracting flow position.
(3) When the pressurizing piston and the detection piston are returned to the origin, the connection switching valve is controlled to be in the parallel connection position and the direction switching valve is controlled to be in the backward flow position.
(4) A squeeze pin control device characterized in that the operating state of the pressurizing piston is detected based on the position of the detection piston detected by the position sensor. A pressure cylinder containing a pressure piston that advances and retreats the squeeze pin,
A detection cylinder containing a detection piston and
A position sensor that detects the position of the detection piston and
It has A port, B port, P port and T port, and has a parallel connection position that communicates A port and T port and communicates B port and P port, and communicates A port and P port and B port. A connection switching valve that has at least a communication position that disconnects the T port and the T port.
It has A port, B port, P port and T port, and has a backward flow position that communicates A port and P port and communicates between B port and T port, and communicates between A port and T port and B port. A directional control valve that has at least a forward flow position that communicates with the P port,
A first flow path connecting the rear oil chamber of the detection cylinder and the B port of the direction switching valve,
A second flow path connecting the front oil chamber of the detection cylinder and the P port of the connection switching valve, and
A third flow path connecting the rear oil chamber of the pressure cylinder and the A port of the connection switching valve,
A fourth flow path connecting the front oil chamber of the pressurizing cylinder, the B port of the connection switching valve, and the A port of the directional switching valve,
Has a control unit,
The P port of the directional control valve is connected to a pump that supplies hydraulic oil.
The T port of the direction switching valve and the T port of the connection switching valve are connected to the tank from which the hydraulic oil is discharged.
The control unit
(1) When the pressurizing piston is advanced, the connection switching valve is controlled to be in the series connection position and the direction switching valve is controlled to be in the forward flow position.
(2) When the pressurizing piston is retracted, the connection switching valve is controlled to be in the series connection position and the direction switching valve is controlled to be in the retracting flow position.
(3) When the pressurizing piston and the detection piston are returned to the origin, the connection switching valve is controlled to be in the parallel connection position and the direction switching valve is controlled to be in the backward flow position.
(4) A squeeze pin control device characterized in that the operating state of the pressurizing piston is detected based on the position of the detection piston detected by the position sensor. The direction switching valve has a flow rate adjusting unit for adjusting the flow rate of the hydraulic oil.
The control unit detects the advancing speed of the pressurizing piston as the operating state of the pressurizing piston, and feedback-controls the flow rate adjusting unit of the direction switching valve so that the advancing speed approaches the set speed. The squeeze pin control device according to claim 1 or 2. The squeeze pin control device according to claim 3, wherein the control unit changes the set speed based on a past forward end position of the pressure piston. The control unit determines whether or not the forward speed of the pressurizing piston is within the normal range set for each time or position, and notifies an abnormality when the speed is not within the normal range. The squeeze pin control device according to claim 3. A mold clamping device for opening and closing the mold, an injection device for injecting molten metal into the cavity of the mold closed in the mold clamping device, and a squeeze pin control device for advancing and retreating the squeeze pin into the cavity of the mold. It is a die casting machine that has
A die casting machine characterized in that the squeeze pin control device is composed of the squeeze pin control device according to any one of claims 1 to 5.

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