JPH08229995A - Ejector control device and ejector control - Google Patents

Abstract

PURPOSE: To make it possible to stop an ejector pin at a correct position by reading a converted extrusion time which corresponds to an extrusion position and an extrusion velocity, then supplying oil to an ejector cylinder by the converted extrusion time using a solenoid switching valve, and moving the ejector pin forward. CONSTITUTION: A first solenoid switching valve 36 is equipped with solenoids Sa, Sb and a spool is caused to move by turning the solenoids Sa, Sb ON/OFF. In accordance with the movement of the spool, a first solenoid switching valve 36 is switched to either of positions A, B or N. Further, both oil passages L-1 and L-2, and oil passages L-3 and L-4 are connected to each other for communication respectively at the position A. The oil discharged by a variable stroke pump 31 is supplied to an oil chamber 13 passing through the oil passages L-1, L-2. On the other hand, the oil in the oil chamber 14 is drained into an oil tank 33 passing through the oil passages L-3, L-4. Thus it is possible to cause an ejector rod 16 and an ejector pin to move forward.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ejector control device and an ejector control method.

[0002]

2. Description of the Related Art Conventionally, in an injection molding machine, a resin heated and melted in a heating cylinder is filled (multiplied) into a cavity space of a mold at a high pressure and cooled in the cavity space. ing. When the cooling step is completed, the mold is opened with the molded product left on the movable side, and the molded product is pushed down by the ejector device.

Therefore, the tip of the ejector pin is disposed so as to face the cavity space, the rear end is fixed to the ejector plate, and the ejector cylinder is connected to the rear end of the ejector plate via an ejector rod. I have to. Therefore, by operating the ejector cylinder and advancing the ejector plate via the ejector rod, the ejector pin fixed to the ejector plate pushes down the molded product.

By the way, in order to surely push down the molded product, the position of the ejector pin is detected by the position detecting device, and the ejector cylinder is operated corresponding to the position of the ejector pin. FIG. 2 is a schematic view of a conventional position detecting device. In the figure, reference numeral 11 is an ejector cylinder, and a piston 12 is slidably arranged inside the ejector cylinder 11, and oil chambers 13 and 14 are formed on both sides of the piston 12. An ejector rod 16 is fixed to the piston 12, and an ejector plate and an ejector pin (not shown) are arranged at the tip of the ejector rod 16.

The ejector rod 16 is provided with a position detector 17 for detecting the position of the ejector pin. The position detection device 17 is fixed to the ejector rod 16 and fixed to the detection shaft 18 and the detection shaft 18 that moves integrally with the ejector rod 16.
8, a rack 19 that moves integrally with the rack 8, a pinion 20 that meshes with the rack 19, and a rotary encoder 21 that measures the rotation of the pinion 20.

When the oil is supplied to the oil chamber 13 and the ejector rod 16 and the ejector pin are advanced, the detection shaft 18 and the rack 19 are also advanced. At this time, the pinion 20 is rotated as the rack 19 moves forward. Therefore, the rotary encoder 21 can detect the position of the ejector pin by measuring the rotation of the pinion 20.

FIG. 3 is a schematic view of another conventional position detecting device. In the figure, 11 is an ejector cylinder,
A piston 12 is slidably arranged in the ejector cylinder 11, and oil chambers 13 and 14 are formed on both sides of the piston 12. The piston 12 has an ejector rod 1
6 is fixed, and an ejector plate and an ejector pin (not shown) are arranged at the tip of the ejector rod 16.

The ejector rod 16 is provided with a position detector 17 for detecting the position of the ejector pin. The position detecting device 17 includes an ejector rod 16
Fixed to the detection shaft 18 that moves integrally with the ejector rod 16, a rod 23 that is fixed to the detection shaft 18 and moves integrally with the detection shaft 18, and a linear scale 25 that measures the amount of movement of the rod 23. Consists of. A potentiometer may be used instead of the linear scale 25.

When the oil is supplied to the oil chamber 13 and the ejector rod 16 and the ejector pin are advanced, the detection shaft 18 and the rod 23 are also advanced. At this time, the linear scale 25 can detect the position of the ejector pin by measuring the moving amount of the rod 23. FIG. 4 is a schematic view of still another conventional position detecting device.

In the figure, 11 is an ejector cylinder, a piston 12 is slidably disposed in the ejector cylinder 11, and oil chambers 13 are provided on both sides of the piston 12.
14 is formed. An ejector rod 16 is fixed to the piston 12, and an ejector plate and an ejector pin (not shown) are arranged at the tip of the ejector rod 16.

The ejector rod 16 is provided with a position detecting device 17 for detecting the position of the ejector pin. The position detecting device 17 includes an ejector rod 16
Fixed to the ejector rod 16 and moving integrally with the ejector rod 16, a proximity switch 27 that measures the passage of the protrusion 26 to detect the retracted limit position of the ejector pin, and similarly measures the passage of the protrusion 26. The proximity switch 28 detects the stroke of the ejector pin. A limit switch may be used instead of the proximity switch 28.

When oil is supplied to the oil chamber 13 and the ejector rod 16 and the ejector pin are advanced, the projection 26 is also advanced. At this time, the position of the ejector pin can be detected by the proximity switch 28 measuring the passage of the protrusion 26.

[0013]

However, in each of the conventional injection molding machines described above, the position detecting device 17 is used.
Since the position of the ejector pin is detected by the above, a space for disposing the position detecting device 17 is required, and the size of the injection molding machine is increased. Also,
Not only are the sensors such as the rotary encoder 21, the linear scale 25, the proximity switch 27, and the proximity switch 28 expensive, but the number of parts is large, so the cost is high.

Therefore, it is conceivable to use a timer instead of the position detecting device 17 and control the protruding amount of the ejector pin by the operating time of the ejector cylinder 11. However, when the ejector pin is moved forward depending on the operating time of the ejector cylinder 11, the ejector pin cannot be stopped at an accurate position when the ejector pin is stopped. Therefore, in order to confirm the forward limit position, it is necessary to dispose an end (not shown) that restricts the movement of the ejector plate in the mold so that the ejector plate contacts the end at the stop position of the ejector pin. Therefore, setting the end becomes difficult.

The present invention solves the problems of the conventional ejector control device and ejector control method described above, so that the ejector pin can be accurately measured without using an ejector pin position detection device, an end for forward limit position confirmation, or the like. An object of the present invention is to provide an ejector control device and an ejector control method that can be stopped at various positions.

[0016]

Therefore, in the ejector control device of the present invention, a variable pump, an ejector rod for actuating an ejector pin, an ejector cylinder for moving the ejector rod forward and backward, and the variable pump are provided. An electromagnetic switching valve disposed between the ejector cylinder and switched by a solenoid to selectively supply oil to the ejector cylinder, and a pressure relief disposed between the variable pump and the electromagnetic switching valve. It has a means, a control device, and a memory.

Then, in the memory, the protruding position and the protruding speed of the ejector pin, and the converted protruding time measured in correspondence with the protruding position and the protruding speed are stored. Further, when the protruding position and the protruding speed are set, the control device reads the converted protruding time corresponding to the protruding position and the protruding speed, and supplies the oil to the ejector cylinder for the converted protruding time by the electromagnetic switching valve. , Advance the ejector pin.

In the ejector control method of the present invention,
Oil is selectively supplied to the ejector cylinder by switching the electromagnetic switching valve, and the ejector pin is moved forward through the ejector rod to cause the ejection. Then, a returning operation step of increasing the pressure of the ejector rod side oil chamber in the ejector cylinder, and a depressurizing step of releasing the pressure of the ejector rod side oil chamber,
There is a pause step of switching the electromagnetic switching valve, and a projecting step of supplying oil to an oil chamber on the piston head side of the ejector cylinder.

[0019]

According to the present invention, in the ejector control device, the variable pump, the ejector rod for operating the ejector pin, the ejector cylinder for moving the ejector rod forward and backward, and the variable pump and the ejector cylinder are provided. An electromagnetic switching valve that is disposed and switched by a solenoid to selectively supply oil to the ejector cylinder; a pressure release means disposed between the variable pump and the electromagnetic switching valve; and a control device. , And a memory.

In this case, when the solenoid is used to switch the electromagnetic switching valve and oil is supplied to the ejector cylinder, the ejector rod is advanced, and accordingly, the ejector pin is advanced to cause the ejector to project. Then, the memory stores the protruding position and the protruding speed of the ejector pin, and the converted protruding time measured corresponding to the protruding position and the protruding speed. Further, when the protruding position and the protruding speed are set, the control device reads the converted protruding time corresponding to the protruding position and the protruding speed, and supplies the oil to the ejector cylinder for the converted protruding time by the electromagnetic switching valve. ,
Move the ejector pin forward.

In this case, when the operator sets the projecting position and the projecting speed, the control device reads the converted projecting time corresponding to the projecting position and the projecting speed, and the electromagnetic switching valve causes the ejector cylinder to convert the oil to the converted projecting time. Is supplied to advance the ejector pin. In the ejector control method of the present invention, the electromagnetic switching valve is switched to selectively supply the oil to the ejector cylinder, and the ejector pin is advanced through the ejector rod to cause the ejector to project.

Then, a return operation step of increasing the pressure of the oil chamber on the ejector rod side in the ejector cylinder, a depressurizing step of releasing the pressure of the oil chamber on the ejector rod side, and a pause step of switching the electromagnetic switching valve. A projecting step of supplying oil to an oil chamber on the piston head side of the ejector cylinder. In this case, the ejector rod-side oil chamber that was once (temporarily) raised in the returning operation step is lowered in the depressurizing step, so that the pressure in the ejector rod-side oil chamber is always constant.

After that, when the electromagnetic switching valve is switched and oil is supplied to the oil chamber on the piston head side, the ejector rod is moved forward and the ejector pin is moved forward accordingly.

[0024]

Embodiments of the present invention will now be described in detail with reference to the drawings. FIG. 5 is a hydraulic circuit diagram in the embodiment of the present invention. In the figure, 11 is an ejector cylinder, and the piston 1 is placed in the ejector cylinder 11.
2 is slidably arranged, and an oil chamber 13 is provided on the piston head side of the piston 12 and an oil chamber 1 is provided on the ejector rod 16 side.
4 are formed respectively. An ejector rod 16 is fixed to the piston 12, and an ejector plate and an ejector pin (not shown) are arranged at the tip of the ejector rod 16.

Further, 31 is a variable pump capable of changing the discharge amount of oil, 32 is an electric motor for driving the variable pump 31, 33 is an oil tank, and 34 is a filter.
The variable pump 31 filters the oil in the oil tank 33 with a filter 3
It is sucked through 4 and discharged at an arbitrary discharge amount. A first electromagnetic switching valve 36 for an ejector is disposed between the variable pump 31 and the ejector cylinder 11, and an oil passage L-1 is provided between the variable pump 31 and the first electromagnetic switching valve 36. 1
An oil passage L-2 is provided between the electromagnetic switching valve 36 and the oil chamber 13, and an oil passage L-3 is provided between the oil chamber 14 and the first electromagnetic switching valve 36.
Oil passages L-4 are respectively arranged between the electromagnetic switching valve 36 and the oil tank 33.

The first electromagnetic switching valve 36 has solenoids Sa and Sb, and the solenoids Sa and Sb are turned on.
When turned off, a spool (not shown) is moved. With the movement of the spool, the first electromagnetic switching valve 36 is switched, and the A position, the B position, and the N position can be taken. Then, at the position A, the oil passage L-
The oil discharged from the variable pump 31 is communicated with the oil passage L-1,
It is supplied to the oil chamber 13 through L-2. On the other hand, the oil chamber 14
The oil inside is drained to the oil tank 33 through the oil passages L-3 and L-4. In this way, the ejector rod 16 and the ejector pin can be advanced.

At position B, the oil passages L-1, L-1
-3 and the oil passages L-2 and L-4 communicate with each other, and the oil discharged by the variable pump 31 is oil passages L-1 and L-3.
And is supplied to the oil chamber 14. On the other hand, the oil in the oil chamber 13 is drained to the oil tank 33 through the oil passages L-2 and L-4. In this way, the ejector rod 16 and the ejector pin can be retracted.

At the N position, the oil passages L-1,
Since the L-2 and the oil passages L-3 and L-4 are cut off,
The ejector rod 16 and the ejector pin do not move forward or backward. An oil passage L-5 is branched and connected to the oil passage L-1 so that oil can be supplied to the depressurizing / automatic temperature raising device 38 via the oil passage L-5.
The depressurizing / automatic temperature raising device 38 and the oil tank 33 are connected by an oil passage L-6.

The depressurizing / automatic temperature raising device 38 branches from the second electromagnetic switching valve 39 and the oil passage L-5 and is connected to the inlet port of the second electromagnetic switching valve 39. , An oil passage L-8 branched from the oil passage L-5 and connected to the outlet port of the second electromagnetic switching valve 39, an inlet of the second electromagnetic switching valve 39 branched from the oil passage L-6. An oil passage L-9 connected to the port, an oil passage L-10 branched from the oil passage L-6 and connected to the outlet port of the second electromagnetic switching valve 39,
And orifices 41 to 44 respectively arranged in the oil passages L-7 to L-10.

The second electromagnetic switching valve 39 has a solenoid Sc, and by turning on / off the solenoid Sc, a spool (not shown) is moved. With the movement of the spool, the second electromagnetic switching valve 39 is switched, and the A position and the B position can be taken. At the position A, the oil passages L-7 and L-8 and the oil passages L-9 and L-10 are communicated with each other, and the oil passage L-5 side and the oil passage L are connected.
The −9 side is separated. Also, at the B position,
The oil passages L-7 and L-9 and the oil passages L-8 and L-10 are communicated with each other, and the oil discharged by the variable pump 31 passes through the oil passage L-5 and then the oil passage L-7. , L-8.

The oil branched to the oil passage L-7 reaches the second electromagnetic switching valve 39 and is drained to the oil tank 33 through the oil passage L-9. During this time, the oil passes through the orifices 41 and 43, so that the temperature is raised by the frictional action. On the other hand, the oil branched to the oil passage L-8 reaches the second electromagnetic switching valve 39, passes through the oil passage L-10, and is drained to the oil tank 33. During this time, the oil passes through the orifices 42 and 44, so that it is heated by friction.

The depressurizing / automatic temperature raising device 38 having the above construction is usually used for automatic temperature raising, but since it is not necessary to raise the temperature automatically during operation, it can also be used for pressure releasing. . A dedicated pressure release valve may be provided instead of the pressure release / automatic temperature raising device 38. Next, the ejector control device will be described.

FIG. 6 is a diagram showing an ejector control device in the embodiment of the present invention. In the figure, 31 is a variable pump, 51 is a control device, 52 is a display device, 53 is a driver for the variable pump 31, 54 is a memory, 55 is an input device, and Sa to Sc are solenoids. The control device 51
The volume of the variable pump 31 is controlled by the solenoids Sa to Sc to be turned on and off.

By the way, in the present embodiment, the position detecting device is not provided, the projecting time is set, and the solenoid Sa is turned on for the projecting time to advance the ejector pin (not shown) to perform the projecting operation. Has become.
Then, various screens can be displayed on the display device 52.

FIG. 7 is a diagram showing a setting screen in the embodiment of the present invention. In the figure, 57 is the display device 52.
It is a setting screen in (FIG. 6). Frames F1 to F3 are set on the setting screen 57, and the protruding position input by the input device 55 is displayed in the frame F1 and the protruding speed input by the input device 55 is displayed in the frame F2. To be done. Further, in the frame F3, the converted protrusion time corresponding to the protrusion position and the protrusion speed is displayed. Then, when the protruding position and the protruding speed are input by the input device 55, the converted protruding time is calculated by the control device 51. Then, ejection is performed by the ejector pin (not shown) for the conversion protrusion time.

By the way, the converted protrusion time is created in advance and calculated by a matrix table stored in the memory 54 as a table. FIG. 1 is a diagram showing a matrix table in the embodiment of the present invention. In this case, the protruding position is divided into 1, 3, 5, 7, 10, and 50 [mm], and the protruding speed is 10, 30, 50, 70, and 99 [%].
The ejector pin (not shown) is moved forward for each combination of each protruding position and each protruding speed, and the protruding time at that time is measured. Then, the measurement result is input to the matrix table. Note that the maximum ejection speed is 100
It is expressed as a percentage when expressed as [%].

The matrix table thus created is stored as a table in the memory 54 (FIG. 6). Further, the operator can operate the input device 55 to display the matrix table on the converted projected time screen of the display device 52. For example, when the ejecting speed is set to 50 [%] and the ejecting time is set to 0.40 [sec] and the ejector pin is advanced, the ejector pin moves to 5%.
When only 0 [mm] is projected, 0.
Enter 40. Further, in this manner, the ejector pin is advanced for each combination of each protruding position and each protruding speed, and the protruding time at that time is measured and input to the matrix table.

In this case, the finer the protruding position and the protruding speed of the matrix table, the more the converted protruding time closer to the actual protruding time can be read. When the ejector pin has a small protrusion amount, the protrusion amount changes greatly only by 0.01 [sec]. Therefore, 1/100 [sec] used in the conventional ejector device
If the precision timer is used, the protrusion amount cannot be finely adjusted. Further, when the protruding time becomes long to some extent, the protruding amount suddenly increases, and the converted protruding time is 1/1
It changes about 00 [sec]. Therefore, the accuracy of the timer is set to the unit of 1/100 to 1/1000 [sec]. Therefore, it is possible to finely adjust the protruding position.

Further, particularly in the manual operation, if the interval (time) of pushing the ejecting button is different, the pressure due to the oil remaining in the oil chamber 14 (FIG. 5) during the previous ejecting varies. As a result, the protruding position changes greatly. Therefore,
A return operation is performed before starting the protrusion to supply oil to the oil chamber 14 to increase the pressure in the oil chamber 14. After that, the pressure in the oil chamber 14 is lowered to a constant value by depressurizing. In this way, the pressure in the hydraulic circuit is stabilized. Next, a rest time is set, and the first electromagnetic switching valve 36 is switched within the rest time to eliminate the error in the switching time of the first electromagnetic switching valve 36.

By this series of operations, it is possible to stabilize the operation of the ejector pin in both the manual operation and the fully automatic operation, and it is possible to eliminate the variation in the protruding position. FIG. 8 is a diagram showing an operation sequence in the embodiment of the present invention. As shown in the figure, the ejecting operation includes a delaying step, a returning operation step, a depressurizing step, a pause step, an ejecting step and a holding step.

In the delay step, the first electromagnetic switching valve 36 (FIG. 5) and the second electromagnetic switching valve 39 are placed in the A position, and the variable pump 31 is stopped. In the return operation step, the first electromagnetic switching valve 36 and the second electromagnetic switching valve 39 are placed in the A position only during the time T1, the variable pump 31 has a pressure of 94% and a flow rate of Q1 [. %].

In the depressurizing step, the first electromagnetic switching valve 36 is placed in the A position and the second electromagnetic switching valve 39 is placed in the B position only during the time T2, and the variable pump 31 has the pressure P.
When the flow rate is 1 [%], the flow rate is Q2 [%]. Further, in the pause step, the first electromagnetic switching valve 36 is in the B position and the second electromagnetic switching valve 39 is in the period T3 as the suspension time.
Is placed in position A, and the variable pump 31 has a pressure of P2 [%].
Then, the flow rate is driven at Q3 [%].

Further, in the projecting step, the first
The electromagnetic switching valve 36 is placed in the B position, the second electromagnetic switching valve 39 is placed in the A position, and the variable pump 31 is driven at a pressure of 94 [%]. Then, in the holding step, the first electromagnetic switching valve 36 is placed in the N position, the second electromagnetic switching valve 39 is placed in the A position, and the variable pump 31 is stopped. It should be noted that the present invention is not limited to the above-described embodiments, and various modifications can be made based on the spirit of the present invention, and they are not excluded from the scope of the present invention.

[0044]

As described in detail above, according to the present invention, in the ejector control device, the variable pump,
An ejector rod for actuating an ejector pin, an ejector cylinder for moving the ejector rod forward and backward, and a variable pump and an ejector cylinder are arranged between the ejector rod and the solenoid, and oil is selectively supplied to the ejector cylinder. Solenoid switching valve to supply,
It has a pressure release means arranged between the variable pump and the electromagnetic switching valve, a control device, and a memory.

Then, in the memory, the protruding position and the protruding speed of the ejector pin, and the converted protruding time measured in correspondence with the protruding position and the protruding speed are stored. Further, when the protruding position and the protruding speed are set, the control device reads the converted protruding time corresponding to the protruding position and the protruding speed, and supplies the oil to the ejector cylinder for the converted protruding time by the electromagnetic switching valve. , Advance the ejector pin.

In this case, when the operator sets the projecting position and the projecting speed, the control device reads the converted projecting time corresponding to the projecting position and the projecting speed, and the electromagnetic switching valve causes the ejector cylinder to convert the oil to the projecting time. Is supplied to advance the ejector pin. Therefore, the ejector pin can be advanced to the correct position. Further, since it is not necessary to detect the position of the ejector pin by the position detection device, a space for disposing the position detection device is not needed, and the injection molding machine can be downsized. Further, since the sensor is not necessary, the number of parts can be reduced and the cost can be reduced.

Further, the end for confirming the forward limit position is unnecessary. In the ejector control method of the present invention, the electromagnetic switching valve is switched to selectively supply the oil to the ejector cylinder, and the ejector pin is advanced through the ejector rod to cause the ejector to project. Then, a return operation step of increasing the pressure of the oil chamber on the ejector rod side of the ejector cylinder,
There are a depressurizing step of releasing the pressure of the oil chamber on the ejector rod side, a pause step of switching the electromagnetic switching valve, and a projecting step of supplying oil to the oil chamber on the piston head side of the ejector cylinder.

In this case, even if the amount of oil remaining in the oil chamber on the ejector rod side fluctuates at the time of the previous projection, the pressure in the oil chamber on the ejector rod side is always kept constant by the returning operation step and the depressurizing step. can do. Therefore, the protruding position by the ejector pin can be made constant. Further, since the electromagnetic switching valve is switched within the rest time, it is possible to eliminate the error in the switching time of the electromagnetic switching valve.

[Brief description of drawings]

FIG. 1 is a diagram showing a matrix table according to an embodiment of the present invention.

FIG. 2 is a schematic diagram of a conventional position detection device.

FIG. 3 is a schematic view of another conventional position detection device.

FIG. 4 is a schematic view of still another conventional position detection device.

FIG. 5 is a hydraulic circuit diagram in the embodiment of the present invention.

FIG. 6 is a diagram showing an ejector control device according to an embodiment of the present invention.

FIG. 7 is a diagram showing a setting screen according to the embodiment of the present invention.

FIG. 8 is a diagram showing an operation sequence in the embodiment of the present invention.

[Explanation of symbols]

 11 Ejector Cylinder 13, 14 Oil Chamber 16 Ejector Rod 31 Variable Pump 36 First Electromagnetic Switching Valve 39 Second Electromagnetic Switching Valve 51 Control Device 54 Memory L1, L4 Oil Passage Sa-Sc Solenoid

Claims (2)

[Claims] 1. A variable pump, (b) an ejector rod for actuating an ejector pin, (c) an ejector cylinder for moving the ejector rod forward and backward,
(D) An electromagnetic switching valve that is disposed between the variable pump and the ejector cylinder and that is switched by a solenoid to selectively supply oil to the ejector cylinder.
(E) The pressure relief device is provided between the variable pump and the electromagnetic switching valve, (f) the control device, and (g) the memory, and (h) the memory includes the ejector. The protruding position and the protruding speed of the pin, and the converted protruding time measured in correspondence with the protruding position and the protruding speed are stored, and (i) the control device controls the protruding position when the protruding position and the protruding speed are set. And an equivalent ejecting time corresponding to the ejecting speed, and the electromagnetic switching valve supplies oil to the ejector cylinder for the equivalent ejecting time to advance the ejector pin. 2. An ejector control method in which oil is selectively supplied to an ejector cylinder by switching an electromagnetic switching valve and the ejector pin is moved forward through an ejector rod to cause ejection, wherein (a) an ejector in the ejector cylinder. A returning operation step of increasing the pressure of the oil chamber on the rod side, (b) a depressurizing step of releasing the pressure of the oil chamber on the ejector rod side, (c) a pause step of switching the electromagnetic switching valve, and (d) And a projecting step of supplying oil to an oil chamber on the piston head side of the ejector cylinder.