JP2001246658A - Core control method for molding machine and device therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a compact core control method by which a core device is controlled through the feed/discharge of a hydraulic oil via a hydraulic oil feed actuator which is driven by an electrically controlled motor, with the applicability of the method to a molding machine having a servo motor-driven mold clamping mechanism as well as a device for controlling the core. SOLUTION: This core control method for a molding machine is operated with such an arrangement that the device comprises hydraulic oil flow channels a-p for the feed and discharge of the hydraulic oil from an oil tank 51 to a core cylinder 38 through the actuator 48 driven by the electrically controlled motors 50, 64 and a valvular means equipped with a switching valve 47 for selecting between the oil flow channels a-p, direction switching valves 46, 48, 58, 60 and the like. In addition, an operation to feed and discharge/return the hydraulic oil from the oil tank 51 to the core cylinder 38, is controlled following the changeover of the valvular means, and a slide core is made to find its way into and out of a cavity along a parting face between the stationary half and the movable half 3, 4 of a mold. Thus the molding of a finished product with a part which becomes an undercut is realized. Also the device for controlling the core is provided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for controlling a core applied to a mold of a molding machine such as an injection molding machine or a die-casting machine. The present invention relates to a core control method and an apparatus which are effective when applied to a molding machine capable of molding a product having an undercut portion using a core.

[0002]

2. Description of the Related Art In general, a hydraulic core control device of a molding machine includes:
When control is performed using pressure oil on the mold clamping side, the injection side, or the like, a part of the pressure oil is used to control the core. FIG. 11 shows a configuration in that case. Supply of the pressure oil to the hydraulic circuit 107 such as the mold clamping side or the injection side is performed by extracting a part of the hydraulic pressure from the middle of the hydraulic pipe 108 as illustrated. Is being done. The hydraulic core control device 80 shown in FIG. 11 basically includes a pressure / flow control circuit 90 for generating hydraulic pressure and a core circuit 110. The pressure / flow rate control circuit 90 for generating hydraulic pressure is provided in the oil tank 9.
1. A supply / discharge hydraulic pump 98, an electromagnetic pressure regulating valve 104, and an electromagnetic flow regulating valve 106. The core circuit 110 includes a pressure reducing valve 112, check valves 114 and 116, a direction switching valve 118, a core It comprises a cylinder 120, a limit switch 122 and the like.

First, a pressure / flow rate control circuit 9 for generating hydraulic pressure
0, the hydraulic oil 92 in the oil tank 91 is supplied from the suction filter 94 and the suction pipe 96 to the supply / discharge hydraulic pump 9.
8 so that it can be supplied to the discharge pipe 100.
Further, a return pipe 102 that returns to the oil tank 90 from the middle of the discharge pipe 100 is provided, and an electromagnetic pressure adjusting valve 104 is attached to the return pipe 102. Further, an electromagnetic flow control valve 106 is provided at the end of the discharge pipe 100, and is connected to the pressure reducing valve 112 constituting the core circuit 110 via the pipe 108 from the electromagnetic flow control valve 106.

Next, the core circuit 110 will be described. A hydraulic pipe 124 from the pressure reducing valve 112 to the core cylinder 120 is described.
, A check valve 114 and a direction switching valve 118 are provided after the pressure reducing valve 112. By switching the direction switching valve 118, pressure oil on the piston head side and the piston rod side in the core cylinder 120 is returned to the oil tank 91 via the check valve 116. The longitudinal movement distance of the piston of the core cylinder 120 is determined by the limit switch 12.
2, the moving distance is limited.

[0005]

However, as in the prior art example shown in the drawing, all the driving sources of a so-called molding machine that uses pressurized oil for the mold clamping side, the injection side, the hydraulic core device, etc., are all hydraulic. In such a case, as long as an oil pump is used as a drive source for supplying the pressure oil, the oil pump needs to be constantly maintained in a rotating state. As another prior art example, there is a case where an electric drive source is used for the mold clamping side and the injection side, and pressure oil is used only for the drive source of the core device. But,
Also in this case, as long as the hydraulic pressure is used for the drive source, the oil pump is constantly rotated. Therefore, disadvantages such as an increase in energy loss cannot be eliminated. Conversely, if all the driving sources such as the mold clamping side, injection side, and core device are electric type molding machines, especially in the core device, the actuator for core operation is driven by a servo motor and ball screw, etc. There is a problem that the space is increased and the cost is increased.

The present invention has been made in view of the above-mentioned conventional problems, and uses hydraulic pressure as a working fluid for driving a core mechanism having a slide core and the like, and also comprises an electric motor including a servomotor, a linear motor, and the like. Drives an actuator formed by a control motor and a transmission mechanism such as a ball screw, and controls the supply and discharge of pressure oil between the oil tank and the core cylinder through the control of valve means such as a switching valve and a direction switching valve. It is an object of the present invention to provide a method and an apparatus for controlling a core of a molding machine which is adapted to perform the operation.

[0007]

In order to achieve the above object, according to a first aspect of the present invention, a rotational force of a servomotor is reduced by a nut and a ball screw shaft into a thrust required for a mold clamping operation of a mold. Equipped with a molding machine equipped with an electric mold clamping device for converting,
A slide core which is applied and has a hydraulically driven core cylinder disposed in a fixed die or a movable die, and is capable of forming a product having a portion which can be moved forward and backward and has an undercut at a tip end of the core cylinder. An oil path is provided between the core cylinder and the oil tank, and an actuator is provided which is capable of supplying operating pressure oil from the oil tank to the core cylinder by using an electric control motor as a drive source. And valve means for switching an oil path provided between the actuator and the core cylinder is disposed, and the actuator and the core cylinder are connected to each other through the oil path by switching the valve means. The core control device of the molding machine is configured so as to supply and discharge the operating pressure oil therebetween, so that molding of a product having a desired undercut portion can be performed.

In a second aspect based on the first aspect, the actuator refuels one end of a ball screw shaft which can move forward and backward in accordance with transmission of a rotational force of a servo motor forming the electric control motor. A first switching valve configured to include a cylinder, wherein the oil path switching valve means is capable of supplying and discharging oil from the oil tank to the core cylinder via the oil supply cylinder; A direction switching valve is provided between the switching valve and the core cylinder, and is capable of supplying the operating pressure oil from the oil supply cylinder to the core cylinder by switching. In a third aspect based on the first aspect, the actuator is provided with a lubricating cylinder at one end of a ball screw shaft capable of moving forward and backward in accordance with transmission of rotational force of a servomotor forming the electric control motor. And the oil path switching valve means is arranged between the refueling cylinder and the core cylinder, and disposed in the order of proximity to the refueling cylinder, followed by the first directional switching valve and the second directional switching valve. By switching between the first directional switching valve and the second directional switching valve, it is possible to supply pressure oil from the oil tank to the core cylinder via the oil supply cylinder, or only the first directional switching valve. The configuration is such that a run-around circuit can be formed in the hydraulic cylinder by switching. Further, a fourth invention based on the first invention is provided.
In the invention, the check valve is arranged between the first switching valve and the direction switching valve or between the first direction switching valve and the second direction switching valve.

In a fifth aspect based on the first aspect, the actuator is configured such that one end of a ball screw shaft capable of moving back and forth in accordance with transmission of a rotational force of a servo motor forming the electric control motor. And a valve means for switching the oil path is provided with a single direction switching valve disposed between the fuel cylinder and the core cylinder. By switching, the pressure oil can be supplied and discharged between the oil tank and the core cylinder via the oil supply cylinder.

[0010] In a sixth aspect based on the first aspect, the first directional control valve is located between the closed hydraulic cylinder and the core cylinder having a moving member which moves forward and backward by a linear motor therein, in the order of proximity to the closed hydraulic cylinder. And a second directional control valve is arranged, and by switching between the first directional control valve and the second directional control valve, pressure oil can be supplied from the oil tank to the core cylinder via the closed hydraulic cylinder. Alternatively, a run-around circuit can be formed in the closed hydraulic cylinder by switching only the first direction switching valve.

[0011] In a seventh invention mainly based on the first invention,
The actuator is provided with a piston pump rotated by a servomotor forming the electric control motor, and the oil path switching valve means is provided with a direction switching valve between the piston pump and the core cylinder. By switching the direction switching valve, the oil from the oil tank can be supplied to and discharged from the core cylinder via the piston pump and the direction switching valve. further,
In the eighth invention based on the first invention, the oil tank for storing the operating pressure oil is configured as an oil tank in which a sealed space is filled with oil as a partition wall made of an elastic member.

In a ninth aspect based on the first aspect, the tank for storing the operating pressure oil is an oil tank which is a partition formed by a piston member and is filled with oil in a closed space. In a tenth aspect based on the first aspect, a direction switching valve is disposed between a piston pump rotated by a servomotor and a core cylinder, and a relief is provided in the hydraulic circuit between the direction switching valve and the piston pump. A valve is provided, and by switching the direction switching valve, oil from an oil tank can be supplied to and discharged from the core cylinder via the piston pump and the direction switching valve.

According to the eleventh aspect, mold clamping is performed by using a rotation / linear conversion mechanism that converts the rotational force of the servo motor into a thrust required for the mold clamping operation of the mold by the nut and the ball screw shaft. The core member and a core cylinder for hydraulically driving the core member are provided in a fixed mold or a movable mold, and the core member is driven to perform molding of a product having an undercut portion. Via an oil path provided between the core cylinder and the oil tank, the actuator is operated from the oil tank to the core cylinder by an actuator having another electric control motor different from the servomotor for mold clamping as a drive source. Supply pressure oil, at this time, by switching the valve means for switching the oil path provided between the actuator and the core cylinder, the actuator and the actuator via the oil path The supply and discharge of the operating pressure oil is controlled between the core cylinder and the core cylinder, and the advance speed of the core cylinder is controlled by the speed of the electric control motor and a torque limit is set to the electric control motor to set the forward speed. The maximum hydraulic pressure of the operating pressure oil supplied to the core cylinder is controlled.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, specific embodiments of a core control device and a control method of a molding machine according to the present invention will be described in detail with reference to the accompanying drawings. FIG. 1 is a sectional view showing an embodiment of a mold clamping device for clamping a mold of an injection molding machine according to the present invention. In FIG. 1, reference numeral 1 denotes a base, on which a fixed die plate 2 is provided.
Are fixed, and a fixed die 3 is attached to the fixed die plate 2. A movable mold 4 is attached to the movable die plate 5 so as to face the fixed mold 3. The movable die plate 5 can move forward and backward using the tie bar 6 as a guide.

Reference numeral 12 denotes a servomotor. The rotational force of the servomotor 12 is transmitted as a thrust of the movable die plate 5 using a transmission mechanism using a ball screw / nut mechanism. A nut 8 is screwed onto the ball screw shaft 7, and a tip end of the nut 8 is fixed to the movable die plate 5. The nut 8 is held by a cylindrical rotating body 9, which is rotatably supported by a support plate 11 via a bearing 10. A pulley 14 around which the timing belt 13 is wound is attached to an end of the rotating body 9 on the side opposite to the nut.

The other pulley 15 is attached to a rotation shaft of the servo motor 12. The torque of the servo motor 12 rotates the rotating body 9 via the timing belt 13. Since the rotating body 9 and the nut 8 rotate integrally,
The rotational motion of the ball nut 8 is converted into a linear motion of the ball screw shaft 7 and transmitted as a linear force of the movable die plate 5. Reference numeral 16 denotes a heating cylinder of the injection device, 18 denotes a fixed mold mounting plate, and 20 denotes a movable mold mounting plate.

Here, the configuration of the core device 40 is shown in FIG.
This will be described in detail with reference to FIG. A plurality of cores of a slide core mold are slidably provided along a parting surface between the fixed mold 3 and the movable mold 4 in order to form an undercut portion during molding. Each slide core 22
A piston rod 42 fixed to a piston (not shown) constituting a core cylinder 38 is directly mounted on the core cylinder 38. One end of the core cylinder 38 is fixed to the outer peripheral portion of the movable mold 4, and the cross section thereof is stepped. It is held by a supporting member 28 having a shape. Reference numeral 26 denotes a spacer block. The spacer block 26 has an ejector plate 24 movably back and forth, and an ejector pin 30 provided on the spacer block 26 slidably penetrates the movable mold 4. The tip has reached the position of the cavity 32.

Reference numeral 34 denotes a push rod. One end of the push rod 34 is mounted on the back surface of the movable mold 4 (the anti-cavity 32) so as to be movable back and forth, and the other end is connected to the ejector plate 24. At the same time, it is urged by a spring 36 to always move backward.

Next, the core control device 44 of the molding machine will be described with reference to FIG.
This will be described in detail with reference to FIGS. Embodiment 1 Embodiment 1 will be described in detail with reference to FIG. First, the core controller 39 includes a core circuit 41 and a pressure / flow rate control circuit 42 for generating hydraulic pressure. The core circuit 41 is connected to the limit switch 37 (37
a, 37b), core cylinder 38, piston rod 4
3, a core device 40 including a piston 44 and a slide core 22, a direction switching valve 46, and a check valve 54. Furthermore, a pressure / flow rate control circuit 4 for generating hydraulic pressure
2 includes a first switching valve 47, an actuator 48, and a hydraulic oil tank 51.

Hydraulic oil is supplied to the core cylinder 38, and a hydraulic oil tank 51 is provided as a supply source.
In order to move the slide core 22, an actuator 48 for temporarily storing and sending hydraulic oil from the hydraulic oil tank 51 via the circulation paths a and b is provided. The actuator 48 includes a ball screw 49, a servomotor 50, a piston 52, a cylinder 53, and a belt 55. In order to reciprocate the piston 52 while controlling the speed of the piston 52, an electric actuator 48 that can move linearly by combining a servo motor 50 and a ball screw 49 as shown in the figure. In order to control the forward speed of the slide core 22, the electric actuator 48 has an encoder 56 attached to a servomotor 50, and detects the position of the piston 52 by a detection signal of the encoder 56.

A position signal from the encoder 56 is input to a controller (not shown), and the hydraulic oil pushing speed of the piston 52 at the position controls the forward speed of the slide core 22. The servo motor 50 is provided with a torque limiter. Based on a signal from the torque limiter, the servo motor driving mechanism limits the servo motor current to suppress the maximum torque generated by the servo motor. The forward speed of the slide core 22 is controlled by the pressure control 38.

A ball screw 49 is fixed to the piston 52 housed in the cylinder 53. The rotation direction of the servo motor 50 is freely reversible, and is transmitted from the drive source of the servo motor 50 to the ball screw 49 via the belt 55, and the ball screw 49 is moved forward and backward, so that the servo motor 50 operates in front of the piston 52. Both the operation of sucking and discharging the hydraulic oil from the oil tank 51 can be performed.
Further, a supply / discharge port 56 is provided in the cylinder 53, and a first switching valve 47 as an electromagnetic valve is interposed in the flow paths a and b extending between the hydraulic oil tank 51 and the supply / discharge port 56, By switching this, when the hydraulic oil is sucked into the cylinder 53 from the hydraulic oil tank 51, the hydraulic oil is communicated with the hydraulic oil tank 51. Further, a direction switching valve 46 is interposed between the first switching valve 47 and the core cylinder 38 as an electromagnetic valve, and is switched to perform a pressing operation (the piston 52 of the actuator 48 advances). Is configured to communicate with the core cylinder 38.

In the illustrated example, when the slide core 22 is advanced by advancing the piston 44 of the core device, the solenoid valves of the first switching valve 47 and the direction switching valve 46 are excited and switched, and the piston 52 of the actuator 48 is advanced. Then, the pressure oil stored on the head side of the piston 52 is introduced into the head side of the piston 44 of the core cylinder 38 via the circulation paths b, c, d, and e. Conversely, when the slide core 22 is moved backward, the direction switching valve 4
When the solenoid valve of No. 6 is excited and switched, the hydraulic oil stored on the head side of the piston 52 is introduced into the rod side of the piston 44 of the core cylinder 38 via the flow paths b, c, d, and f. The hydraulic oil 44 is retracted and discharged to the hydraulic oil tank 51 via the circulation paths e and g. Reference numerals 37a and 37b denote limit switches.
Indicates the retreat limit, respectively. The check valve 54 provided in the core circuit 41 is provided to maintain the hydraulic pressure in the core cylinder 38 in accordance with the switching of the direction switching valve 46.

The molding operation of the core control device of the molding machine configured as described above will be described. First, in the state shown in FIG. 3, when the servo motor 12 is rotated at a high speed and a low torque, the rotating force rotates the rotating body 9 via the timing belt 13. Since the rotating body 9 and the nut 8 rotate integrally, the rotational movement of the ball nut 8 is
This is converted into a linear motion for moving the ball screw shaft 7 forward. At this time, the thrust of the ball screw shaft 7 is
Is transmitted as a linear force to advance the fixed mold 3 and the movable mold 4 are closed.

Then, after the fixed mold 3 and the movable mold 4 are joined, the operation of the core control device 39 is started. Until then, the slide core 22 is at the most retracted position where the slide core 22 is most retracted from the cavity 32. is there. First, in the suction operation, the first switching valve 47 is demagnetized (as shown), and the actuator 4
8 is in communication with the hydraulic oil tank 51. A retract command signal is output to the servo motor 50 of the actuator 48, and the piston 52 is retracted and stopped while monitoring the position signal. Sunaho, the servo motor 50 is turned,
The rotation is transmitted to the ball screw 49 via the belt 55. When the piston 52 is retracted, the operating oil is transferred from the operating oil tank 51 through the flow paths a and b to the electric actuator 4.
8 is sucked and stored in the head side of the piston 52.

After the suction operation is completed, a discharge operation is started. First, a driver (not shown) outputs a forward command signal to the electric actuator 48. At this time, an excitation signal is output to the first switching valve 47 and the direction switching valve 46, and the electric actuator 48 and the core cylinder 3
8 is in communication with the head side of the piston 44. The forward command signal to the electric actuator 48 is an operation speed of the actuator corresponding to a preset flow rate. When the pressure oil is introduced to the head side of the piston 44 of the core cylinder 38 and the piston rod 43 of the piston 44 advances, the slide 22 stops at the advance limit by kicking the advance limit switch 37a.

After that, the servo motor 12 is switched to an extremely low speed and high torque rotation to generate a predetermined final mold clamping force. After a predetermined cooling time elapses after the molten resin is injected into the cavity 32, the servomotor 12 rotates in the reverse direction and the two dies 3, 4 are opened. Cavity 3
First, the slide core 22 is retracted in order to remove the slide core 22 from the slide core 22, which is performed as follows. That is, after the slide core 22 is advanced to the forward limit as described above, the molten resin is injected into the cavity 32, and then the holding pressure and cooling of the mold are completed, and the solidification of the injected and filled resin is completed. The servomotor 50, which has been advanced in order to move the piston 44 of the core cylinder 38 to the forward chord while the valves 3 and 4 are open, is rotated to retract the piston 52 to the retreat limit.

In order to remove the cooled and solidified molded product from the cavity 32, an excitation signal is output to the first switching valve 47 and the direction switching valve 46, and the electric actuator 48 communicates with the piston rod 43 side of the core cylinder 38. In state. The forward command signal to the electric actuator 48 is an operation speed of the actuator corresponding to a preset flow rate. At this time, the piston rod 4 of the piston 44
When the backward limit switch 37b is kicked at the time of the backward movement of the slide 3, the slide core 22 stops at the backward limit.
As a result, the molded product from which the undercut portion has been caught is moved via the ejector plate 24 and the ejector pin 30 when the push rod 34 is operated because the movable mold 4 is retracted by a predetermined amount and is in the mold open state. The molded product is pushed down from the mold 4.

Embodiment 2 Embodiment 2 will be described in detail with reference to FIG. First, the core control device 39
It is composed of a core circuit 41 and a pressure / flow control circuit 42 for generating hydraulic pressure. The core circuit 41 includes a limit switch 37 (37a, 37b), a core cylinder 38, a piston rod 43, a piston 44, and the slide core 22. Further, the hydraulic pressure generation / flow control circuit 42 includes an actuator 48, a direction switching valve 58, and a hydraulic oil tank 51.

Hydraulic oil is supplied to the core cylinder 38, and a hydraulic oil tank 51 is provided as a supply source.
In order to move the slide core 22, an actuator 48 for temporarily storing and sending hydraulic oil from the hydraulic oil tank 51 via the circulation paths h and i is provided. The actuator 48 includes a ball screw 49, a servomotor 50, a piston 52, a cylinder 53, and a belt 55. In order to reciprocate the piston 52 while controlling the speed of the piston 52, an electric actuator 48 that can move linearly by combining a servo motor 50 and a ball screw 49 as shown in the figure. In order to control the forward speed of the slide core 22, the electric actuator 48 has an encoder 56 attached to a servomotor 50, and detects the position of the piston 52 by a detection signal of the encoder 56.

A torque limit or speed signal is input from a driver (not shown) to the servomotor 50, and the hydraulic oil pushing speed of the piston 52 at the position controls the forward speed of the slide core 22.
For this reason, the servo motor 50 is provided with a torque limiter. Based on a signal from the torque limiter, the servo motor driving mechanism limits the servo motor current.
The maximum generated torque of the servomotor is suppressed, and the forward speed of the slide core 22 is controlled by controlling the pressure of the core cylinder 38.

A ball screw 49 is fixed to the piston 52 housed in the cylinder 53. The rotation direction of the servo motor 50 is freely reversible, and is transmitted from the drive source of the servo motor 50 to the ball screw 49 via the belt 55, and the ball screw 49 is moved forward and backward, so that the servo motor 50 operates in front of the piston 52. It is configured such that both the operation of sucking and discharging the hydraulic oil from the oil tank 51 can be performed.

Further, the cylinder 53 is provided with a supply / discharge port 56, and a flow path h, i extending between the hydraulic oil tank 51 and the supply / discharge port 56 is provided with a direction switching valve 58 as a switching valve. By switching this, when the hydraulic oil is sucked from the hydraulic oil tank 51 into the cylinder 53, the hydraulic oil is communicated with the hydraulic oil tank 51. Further, a direction switching valve 58 is interposed between the actuator 48 and the core cylinder 38, and by switching this, a pressing operation (the piston 52 of the actuator 48 moves forward).
In this case, the core cylinder 38 is connected.

In the illustrated example, the piston 4 of the core device 40
When the slide core 22 is moved forward by the forward movement of the piston 4, the solenoid valve of the direction switching valve 58 is excited and switched, and the piston 52 of the actuator 48 is moved forward to move the piston 5.
The pressure oil stored in the second head side is introduced into the head side of the piston 44 of the core cylinder 38 via the flow paths i and j.

On the other hand, when the slide core 22 is moved backward, the solenoid valve of the direction switching valve 58 is excited to move the piston 5.
2 is introduced into the rod side of the piston 44 of the core cylinder 38 via the flow paths i and k, and the hydraulic oil stored on the piston head side when the piston 44 retreats. Is discharged to the hydraulic oil tank 51 via the circulation paths j and h. Reference numerals 37a and 37b denote limit switches, 37a denotes a forward limit switch, and 37b denotes a limit switch backward limit.

The molding operation of the core control device of the molding machine configured as described above will be described. Embodiments 2 to 8
The description of the mold clamping device of the injection molding machine used for the present embodiment is the same as that of FIG. 3 and therefore will not be repeated. Hereinafter, only the core control device of each embodiment will be described. First, in the second embodiment,
After the fixed mold 3 and the movable mold 4 are joined, the operation of the core control device 39 is started.
Numeral 2 is at the retreat limit position most retreated from the cavity 32. First, in the suction operation, the direction switching valve 58 is demagnetized (as shown), and the actuator 48
It is in a state of contact with 1. A retract command signal is output to the servo motor 50 of the actuator 48, and the piston 52 is retracted and stopped while monitoring the position signal. That is, the servo motor 50 is rotated, and the rotation is transmitted to the ball screw 49 via the belt 55. When the piston 52 is retracted, hydraulic oil is sucked and stored from the hydraulic oil tank 51 through the flow paths h and i on the head side of the piston 52 of the electric actuator 48.

After the suction operation is completed, the discharge operation is started. First, a driver (not shown) outputs a forward command signal to the electric actuator 48. At that time, an excitation signal is output to the direction switching valve 58, and the electric actuator 48 and the piston 44 of the core cylinder 38 are output.
Is in communication with the head side. Electric actuator 4
The forward command signal to 8 is the operation speed of the actuator corresponding to the preset flow rate. When the pressure oil is introduced into the head side of the piston 44 of the core cylinder 38 and the forward limit switch 37a is kicked when the piston rod 43 of the piston 44 advances, the slide core 22 stops at the forward limit.

After that, the servo motor 12 is switched to an extremely low speed and high torque rotation to generate a predetermined final mold clamping force. When a predetermined cooling time elapses after the molten resin is injected into the cavity 32, the servomotor 12 reversely rotates to open the two dies 3, 4. Cavity 3
First, the slide core 22 is retracted in order to remove the slide core 22 from the slide core 22, which is performed as follows. That is, after the slide core 22 is advanced to the forward limit as described above, the molten resin is injected into the cavity 32, and then the holding pressure and cooling of the mold are completed, and the solidification of the injected and filled resin is completed. The servomotor 50 which has been advanced in order to move the piston 44 of the core cylinder 38 to the forward limit while opening 3 and 4 is rotated, and the piston 52 is retracted to the retract limit.

In order to remove the cooled and solidified molded product from the cavity 32, an excitation signal is output to the direction switching valve 58, and the electric actuator 48 and the piston rod 43 side of the core cylinder 38 are in communication. At this time, the forward command signal to the electric actuator 48 is the operation speed of the actuator corresponding to the preset flow rate. At this time, when the piston 44 of the piston 44 retreats, the slide core 22 stops at the retreat limit by kicking the retreat limit switch 37b. As a result, the molded product from which the undercut portion is no longer caught can be ejected when the push rod 34 is operated because the movable mold 4 is retracted by a predetermined amount and is in the mold open state.
The molded product is pushed down from the movable mold 4 via the ejector pins 30.

Third Embodiment A third embodiment will be described in detail with reference to FIG. First, the core control device 39
It is composed of a core circuit 41 and a pressure / flow control circuit 42 for generating hydraulic pressure. The core circuit 41 includes a core device 40 including a limit switch 37 (37a, 37b), a core cylinder 38, a piston rod 43, a piston 44, and a slide core 22, a second directional control valve 46, and a check valve. 54. In addition, the hydraulic pressure
The flow control circuit 42 includes an actuator 48, a hydraulic oil tank 51, and a first direction switching valve 60.

Hydraulic oil is supplied to the core cylinder 38, and a hydraulic oil tank 51 is provided as a supply source.
In order to move the slide core 22, an actuator 48 for temporarily storing and sending hydraulic oil from the hydraulic oil tank 51 via the circulation paths a and b is provided. The actuator 48 includes a ball screw 49, a servomotor 50, a piston 52, a cylinder 53, and a belt 55.

In order to reciprocate while controlling the speed of the piston 52, an electric actuator 48 that can move linearly by combining a servo motor 50 and a ball screw 49 as shown in the figure. The electric actuator 48 has an encoder 56 attached to a servo motor 50 to control the forward speed of the slide core 22.
6, the position of the piston 52 is detected.

A torque limit or speed signal is input from a driver (not shown) to the servomotor 50, and the hydraulic oil pushing speed of the piston 52 at the position controls the forward speed of the slide core 22.
For this reason, the servo motor 50 is provided with a torque limiter. Based on a signal from the torque limiter, the servo motor driving mechanism limits the servo motor current.
The maximum generated torque of the servomotor is suppressed, and the forward speed of the slide core 22 is controlled by controlling the pressure of the core cylinder 38.

A ball screw 49 is fixed to the piston 52 housed in the cylinder 53. The rotation direction of the servo motor 50 is freely reversible, and is transmitted from the drive source of the servo motor 50 to the ball screw 49 via the belt 55, and the ball screw 49 is moved forward and backward, so that the servo motor 50 operates in front of the piston 52. Both the operation of sucking and discharging the hydraulic oil from the oil tank 51 can be performed.

Further, a supply / drain port 56 is provided in the cylinder 53, and a first direction switching valve 60 is provided as a switching valve in the flow paths a and b extending between the hydraulic oil tank 51 and the supply / drain port 56. By switching this, communication with the hydraulic oil tank 51 is established. A second directional control valve 46 is interposed between the first directional control valve 60 and the core cylinder 38. By switching the second directional control valve 46, a pressing operation (the piston 52 of the actuator 48 moves forward) is performed. Is configured to communicate with the core cylinder 38.

In the illustrated example, when the slide core 22 is advanced by advancing the piston 44 of the core device, the solenoid valves of the first directional switching valve 60 and the second directional switching valve 46 are excited and switched, and the piston of the actuator 48 is switched. 52
Is advanced, and the pressure oil stored on the head side of the piston 52 is introduced into the head side of the piston 44 of the core cylinder 38 via the circulation paths b, c, d, and e.

On the other hand, when the slide core 22 is moved backward, the solenoid valve of the second direction switching valve 46 is excited, and the pressure oil stored on the head side of the switching piston 52 flows through the circulation paths b and b.
When introduced into the rod side of the piston 44 of the core cylinder 38 via c, d and f, the piston 44 retreats and the hydraulic oil stored on the piston head side flows through the flow paths e and g.
Is discharged to the hydraulic oil tank 51 via the

Next, in the present embodiment, the first
A run-around circuit is formed in the direction switching valve 60. Assuming that the run-around circuit is not used while the area ratio between the head side and the rod side of the piston 52 is 2: 1,
When using a run-around circuit, the hydraulic oil
Since the pressure is doubled, the pressure must be doubled accordingly. For this reason, there is a problem that a motor having a large torque of the servo motor 50 is required. On the other hand, in order to solve such a problem, in the present embodiment, a run-around circuit is used, for example, when the area ratio between the head side and the rod side of the piston 52 of the actuator 48 is 2: 1. The same pressure can be generated with the same propulsive force (torque) in forward and backward movements.

That is, the hydraulic oil stored on the head side of the piston 52 is moved forward by the servo motor 50 to advance the piston 52 and the piston 44 of the core cylinder 38
When feeding to the head side or rod side of
When the area ratio between the head side and the rod side is 2: 1, the same amount of hydraulic oil as the amount of hydraulic oil fed from the actuator 48 to the It returns to the rod side (ball screw side). Reference numerals 37a and 37b are limit switches, 37a is a forward limit switch, and 37b is a limit switch.
Indicates a backward limit switch.

The molding operation of the core control device of the molding machine configured as described above will be described. First, in the state shown in FIG. 5, after the fixed mold 3 and the movable mold 4 are mold-joined,
The operation of the core control device 39 is started. Until then, the slide core 22 is at the retreat limit position most retracted from the cavity 32. First, in the suction operation, the solenoid valve of the first direction switching valve 60 is excited, and the actuator 48 is in a state of being in communication with the hydraulic oil tank 51. A retract command signal is output to the servo motor 50 of the actuator 48, and the piston 52 is retracted and stopped while monitoring the position signal. That is, the servo motor 50 is rotated, and the rotation is transmitted to the ball screw 49 via the belt 55. When the piston 52 is retracted, hydraulic oil is sucked and stored from the hydraulic oil tank 51 through the flow paths a and b on the head side of the piston 52 of the electric actuator 48.

After the suction operation is completed, the discharge operation starts. First, a driver (not shown) outputs a forward command signal to the electric actuator 48. Therefore, an excitation signal is output to the first directional control valve 60 and the second directional control valve 46, and the electric actuator 48 and the head side of the piston 44 of the core cylinder 38 are in communication. The forward command signal to the electric actuator 48 is an operation speed of the actuator corresponding to a preset flow rate. When the hydraulic oil is introduced into the head side of the piston 44 of the core cylinder 38 and the piston rod 43 of the piston 44 advances, the forward limit switch 37a is kicked to stop the slide core 22 at the forward limit. In this case, the amount of hydraulic oil introduced into the head side of the piston 44 of the core cylinder 38 and the amount of hydraulic oil returning from the first directional control valve 60 to the actuator 48 via the flow path B of the run-around circuit are the same. As a result, the forward and backward moving speeds of the slide core 22 of the core cylinder 38 become the same.

After that, the servo motor 12 is switched to an extremely low speed and high torque rotation to generate a predetermined final mold clamping force. When a predetermined cooling time elapses after the molten resin is injected into the cavity 32, the servomotor 12 reversely rotates to open the two dies 3, 4. Cavity 3
First, the slide core 22 is retracted in order to remove the slide core 22 from the slide core 22, which is performed as follows. That is, as described above, after the slide core 22 is advanced to the forward limit, the molten resin is injected into the cavity 32, and then the holding pressure and the mold are cooled to complete the solidification of the injected and filled resin. Piston 4 of core cylinder 38 while opening 3, 4
In order to move the piston 4 to the forward limit, the servo motor 50 which has been advanced is rotated to rotate the piston 52 backward to the retract limit.

In order to remove the cooled and solidified molded product from the cavity 32, an excitation signal is output to the first switching valve 47 and the direction switching valve 46, and the electric actuator 48 and the piston rod 43 side of the core cylinder 38 communicate with each other. In state. The forward command signal to the electric actuator 48 is an operation speed of the actuator corresponding to a preset flow rate. At this time, the piston rod 4 of the piston 44
When the backward limit switch 37b is kicked at the time of the backward movement of the slide 3, the slide core 22 stops at the backward limit.
As a result, the molded product from which the undercut portion is no longer caught is in a mold open state with the movable mold 4 retracted by a predetermined amount. Therefore, when the push rod 34 is actuated, the ejector plate 24 and the ejector pin 30 are used. The molded product is pushed down from the movable mold 4.

Embodiment 4 Embodiment 4 will be described in detail with reference to FIG. First, the core control device 39
It is composed of a core circuit 41 and a pressure / flow control circuit 42 for generating hydraulic pressure. The core circuit 41 includes a core device 40 including a limit switch 37 (37a, 37b), a core cylinder 38, a piston rod 43, a piston 44, and a slide core 22, a second directional control valve 46, and a check valve. 54. In addition, the hydraulic pressure
The flow control circuit 42 includes a hydraulic oil tank 51, a first switching valve 4
7 and a closed hydraulic cylinder 62.

Hydraulic oil is supplied to the core cylinder 38, and a hydraulic oil tank 51 is provided as a supply source.
A closed hydraulic cylinder 62 is provided for temporarily storing and sending hydraulic oil from the hydraulic oil tank 51 via the flow paths a and b in order to move the slide core 22. Further, the closed hydraulic cylinder 62 is
4 and a compression member 66.

The compression member 66 is accommodated in the closed hydraulic cylinder 62, and moves backward due to the strength of the induced current of the linear motor 64 disposed in the closed hydraulic cylinder 62 at a distance from the periphery of the compression member 66. In addition, the speed can be adjusted. Further, a liquid storage chamber 68 is provided before and after the compression member 66, and both the suction and discharge operations of the hydraulic oil from the hydraulic oil tank 51 can be performed by the forward and backward movement of the compression member 66.

Further, the closed hydraulic cylinder 62 is provided with a supply / discharge port 56, and the hydraulic oil tank 51 and the supply / discharge port 56 are provided.
A first switching valve 4 is provided as a switching valve in the flow paths a and b between
7, and by switching this, communication with the hydraulic oil tank 51 is made. A second directional switching valve 46 is interposed between the first switching valve 47 and the core cylinder 38. By switching the second directional switching valve 46, the pressing operation (the compression member 66 of the closed hydraulic cylinder 62 advances). )
In this case, the core cylinder 38 is connected.

In the illustrated example, when the slide core 22 is advanced by advancing the piston 44 of the core device, the solenoid valves of the first switching valve 60 and the second directional switching valve 46 are excited and switched, and the closed hydraulic cylinder 62 is switched. When the compression member 66 is advanced, the liquid storage chamber 6 in front of the closed hydraulic cylinder 62 is moved.
The hydraulic oil stored in the cylinder 8 is introduced into the head side of the piston 44 of the core cylinder 38 via the circulation paths b, c, d, and e.

Conversely, when the slide core 22 is retracted, the solenoid valve of the first switching valve 47 and the solenoid valve of the second directional switching valve 46 are excited and switched, and the liquid storage chamber 68 in front of the closed hydraulic cylinder 62 is switched. Hydraulic oil stored in the distribution channel b,
Hydraulic oil introduced to the rod side of the piston 44 of the core cylinder 38 via c, d and f, the piston 44 retreats, and the hydraulic oil stored on the piston head side flows through the hydraulic oil tank 51 via the flow paths e and g. It is configured to be discharged to Reference numerals 37a and 37b denote limit switches, 37a denotes a forward limit switch, and 37b denotes a backward limit switch.

The molding operation of the core control device of the molding machine configured as described above will be described. First, in the state shown in FIG. 6, after the fixed mold 3 and the movable mold 4 are mold-joined,
The operation of the core control device 39 is started. Until then, the slide core 22 is at the retreat limit position most retracted from the cavity 32. First, in the suction operation, the solenoid valve of the first switching valve 47 is demagnetized, and the closed hydraulic cylinder 62 is
It is assumed that it is in contact with 1. When a retraction command signal is output to the linear motor 64 of the closed hydraulic cylinder 62 and the compression member 66 is retracted while monitoring the position signal, the hydraulic oil tank 5
Hydraulic oil is sucked and stored in the liquid storage chamber 68 in front of the closed hydraulic cylinder 62 through the flow paths a and b from 1.

After the suction operation is completed, a discharge operation is started. First, a driver (not shown) outputs a forward command signal to the closed hydraulic cylinder 62. At this time, an excitation signal is output to the first switching valve 47 and the second directional switching valve 46, and the closed hydraulic cylinder 62 and the core cylinder 3
8 is in communication with the head side of the piston 44. The advance command signal of the compression member 66 of the closed hydraulic cylinder 62 is an operation speed of the compression member 66 corresponding to a preset flow rate. When the hydraulic oil is introduced into the head side of the piston 44 of the core cylinder 38 and the piston rod 43 of the piston 44 advances, the forward limit switch 37a is kicked to stop the slide core 22 at the forward limit.

Thereafter, the servo motor 12 is switched to an extremely low speed and high torque rotation to generate a predetermined final mold clamping force. When a predetermined cooling time elapses after the molten resin is injected into the cavity 32, the servomotor 12 reversely rotates to open the two dies 3, 4. Cavity 3
First, the slide core 22 is retracted in order to remove the slide core 22 from the slide core 22, which is performed as follows. That is, after the slide core 22 is advanced to the forward limit as described above, the molten resin is injected into the cavity 32, and then the holding pressure and cooling of the mold are completed, and the solidification of the injected and filled resin is completed. The servomotor 50 which has been advanced in order to move the piston 44 of the core cylinder 38 to the forward limit while opening 3 and 4 is rotated, and the piston 52 is retracted to the retract limit.

In order to take out the cooled and solidified molded product from the cavity 32, an excitation signal is output to the first switching valve 47 and the second directional switching valve 46, and the liquid storage chamber 68 in front of the closed hydraulic cylinder 62 is connected to the inside. Piston rod 4 of slave cylinder 38
The three sides are in communication. At this time, the piston 44
When the piston rod 43 is retracted, the slide core 22 stops at the retreat limit by kicking the retreat limit switch 37b. As a result, the molded product from which the undercut portion has been caught is moved via the ejector plate 24 and the ejector pin 30 when the push rod 34 is operated because the movable mold 4 is retracted by a predetermined amount and is in the mold open state. The molded product is pushed down from the mold 4.

[Fifth Embodiment] A fifth embodiment will be described in detail with reference to FIG. First, the core control device 39
It is composed of a core circuit 41 and a pressure / flow control circuit 42 for generating hydraulic pressure. The core circuit 41 includes a core device 40 including a limit switch 37 (37a, 37b), a core cylinder 38, a piston rod 43, a piston 44, and a slide core 22, a direction switching valve 46 and a check valve 54, Consists of In addition, the hydraulic pressure
The flow control circuit 42 includes a servomotor 50, a hydraulic oil tank 51, and a piston pump 70.

Hydraulic oil is supplied to the core cylinder 38, and a hydraulic oil tank 51 is provided as a supply source.
A piston pump 70 for supplying hydraulic oil from the hydraulic oil tank 51 to the core cylinder 38 via the circulation path m
Is provided. The piston pump 70 is directly connected to the servomotor 50, and rotates the servomotor 50 to rotate the piston pump 70.

The hydraulic oil tank 51 and the piston pump 70 are connected by a flow path m, and the flow paths n, o,
A check valve 54 and a direction switching valve 46 are interposed in p.
By switching the direction switching valve 46, the hydraulic oil tank 51
Is to be contacted.

In the example shown in the figure, when the slide core 22 is advanced by advancing the piston 44 of the core device, when the solenoid valve of the direction switching valve 46 is excited and switched while the piston pump 70 is rotated, the hydraulic oil flows. Path m, n, o, p
Through the core cylinder 38 to the head side of the piston 44.

On the other hand, when the slide core 22 is retracted, the direction switching valve 46 is maintained while the piston pump 70 is rotated.
When the electromagnetic valve is excited and switched, hydraulic oil is introduced from the hydraulic oil tank 51 to the rod side of the piston 44 of the core cylinder 38 via the flow paths m, n, o, and q.
The hydraulic fluid 4 is retracted and the hydraulic oil stored on the piston head side is discharged to the hydraulic oil tank 51 via the flow paths p and r. Reference numerals 37a and 37b denote limit switches, 37a denotes a forward limit switch, and 37b denotes a backward limit switch.

The molding operation of the core control device of the molding machine configured as described above will be described. First, in the state shown in FIG. 7, after the fixed mold 3 and the movable mold 4
The operation of the core control device 39 is started. Until then, the slide core 22 is at the retreat limit position most retracted from the cavity 32. First, in the suction operation, the solenoid valve of the direction switching valve 46 is excited to bring the core cylinder 38 and the hydraulic oil tank 51 into communication. When the piston pump 70 is rotated, hydraulic oil is supplied from the hydraulic oil tank 51 to the head side of the piston 44 of the core cylinder 38 through the flow paths m, n, o, and p. When hydraulic oil is introduced to the head side of the piston 44 of the core cylinder 38 and the piston rod 43 of the piston 44 advances, the forward limit switch 3
By kicking 7a, the slide core 22 stops at the forward limit.

After that, the servo motor 12 is switched to an extremely low speed and high torque rotation to generate a predetermined final mold clamping force. When a predetermined cooling time elapses after the molten resin is injected into the cavity 32, the servomotor 12 reversely rotates to open the two dies 3, 4. Cavity 3
First, the slide core 22 is retracted in order to remove the slide core 22 from the slide core 22, which is performed as follows. That is, after the slide core 22 is advanced to the forward limit as described above, the molten resin is injected into the cavity 32, and then the holding pressure and cooling of the mold are completed, and the solidification of the injected and filled resin is completed. In order to move the piston 44 of the core cylinder 38 to the forward limit while opening 3 and 4, the servo motor 50 which has been advanced is rotated and the piston 52 is retracted to the retract limit.

In order to remove the cooled and solidified molded product from the cavity 32, an excitation signal is output to the direction switching valve 46, and the piston pump 70 and the piston rod 43 of the core cylinder 38 are in communication. At this time, when the piston 44 of the piston 44 retreats, the slide core 22 stops at the retreat limit by kicking the retreat limit switch 37b. As a result, the molded product from which the undercut portion has been caught is removed from the push rod 34 because the movable mold 4 is retracted by a predetermined amount and is in the mold open state.
Is activated, the ejector plate 24, the ejector pin 3
The molded product is pushed down from the movable mold 4 through the “0”.

Embodiment 6 Embodiment 6 will be described in detail with reference to FIG. First, the core controller 39 includes a core circuit 41 and a pressure / flow rate control circuit 42 for generating hydraulic pressure. The core circuit 41 includes a core device 40 including a limit switch 37 (37a, 37b), a core cylinder 38, a piston rod 43, a piston 44, and a slide core 22, a direction switching valve 46 and a check valve 54, Consists of Further, the hydraulic pressure generating pressure / flow rate control circuit 42 includes a servo motor 50, a hydraulic oil tank 5
1 and a piston pump 70.

Hydraulic oil is supplied to the core cylinder 38, and a hydraulic oil tank 51 is provided as a supply source.
A piston pump 70 for supplying hydraulic oil from the hydraulic oil tank 51 to the core cylinder 38 via the circulation path m
Is provided. The piston pump 70 is directly connected to the servomotor 50, and rotates the servomotor 50 to rotate the piston pump 70.

The hydraulic oil tank 51 and the piston pump 70 are connected by a flow path m, and the flow paths n, o, and n between the piston pump 70 and the core cylinder 38.
A check valve 54 and a direction switching valve 46 are interposed in p.
By switching the direction switching valve 46, the hydraulic oil tank 51
Is to be contacted. This hydraulic oil tank 51
Is composed of a straight body portion, an outer shell 51a having hemispherical lids above and below the straight body portion, and a telescopic member 72 that seals the working oil inside and prevents shaking due to the vibration of the working oil.

In the illustrated example, when the slide core 22 is advanced by advancing the piston 44 of the core device, if the solenoid valve of the direction switching valve 46 is excited and switched while the piston pump 70 is rotated, the hydraulic oil flows. Path m, n, o, p
Through the core cylinder 38 to the head side of the piston 44.

On the other hand, when the slide core 22 is moved backward, the direction switching valve 46 is maintained while the piston pump 70 is rotated.
When the electromagnetic valve is excited and switched, hydraulic oil is introduced from the hydraulic oil tank 51 to the rod side of the piston 44 of the core cylinder 38 via the flow paths m, n, o, and q.
The hydraulic fluid 4 is retracted and the hydraulic oil stored on the piston head side is discharged to the hydraulic oil tank 51 via the flow paths p and r. Reference numerals 37a and 37b denote limit switches, 37a denotes a forward limit switch, and 37b denotes a backward limit switch.

The molding operation of the core control device of the molding machine configured as described above will be described. First, in the state shown in FIG. 8, after the fixed mold 3 and the movable mold 4 are mold-joined,
The operation of the core control device 39 is started. Until then, the slide core 22 is at the retreat limit position most retracted from the cavity 32. First, in the suction operation, the solenoid valve of the direction switching valve 46 is excited to bring the core cylinder 38 and the hydraulic oil tank 51 into communication. When the piston pump 70 is rotated, hydraulic oil is supplied from the hydraulic oil tank 51 to the head side of the piston 44 of the core cylinder 38 through the flow paths m, n, o, and p. When hydraulic oil is introduced to the head side of the piston 44 of the core cylinder 38 and the piston rod 43 of the piston 44 advances, the forward limit switch 3
By kicking 7a, the slide core 22 stops at the forward limit.

Thereafter, the servo motor 12 is switched to an extremely low speed and high torque rotation to generate a predetermined final clamping force. When a predetermined cooling time elapses after the molten resin is injected into the cavity 32, the servomotor 12 reversely rotates to open the two dies 3, 4. Cavity 3
First, the slide core 22 is retracted in order to remove the slide core 22 from the slide core 22, which is performed as follows. That is, after the slide core 22 is advanced to the forward limit as described above, the molten resin is injected into the cavity 32, and then, the holding pressure and cooling of the mold are completed, and the solidification of the injected and filled resin is completed. The servomotor 50 which has been advanced in order to move the piston 44 of the core cylinder 38 to the forward limit while opening 3 and 4 is rotated, and the piston 52 is retracted to the retract limit.

In order to remove the cooled and solidified molded product from the cavity 32, an excitation signal is output to the direction switching valve 46, and the piston pump 70 and the piston rod 43 side of the core cylinder 38 are in communication. At this time, when the piston 44 of the piston 44 retreats, the slide core 22 stops at the retreat limit by kicking the retreat limit switch 37b. As a result, the molded product from which the undercut portion has been caught is removed from the push rod 34 because the movable mold 4 is retracted by a predetermined amount and is in the mold open state.
Is activated, the ejector plate 24, the ejector pin 3
The molded product is pushed down from the movable mold 4 through the “0”.

Embodiment 7 Embodiment 7 will be described with reference to FIG. Note that only the configuration of the hydraulic oil tank 51 is different from that of FIG. 8 except that the configuration of the hydraulic oil tank 51 is different. The hydraulic oil tank 51 shown in FIG. 9 has a cylindrical straight body portion 51a and a cylindrical shape having lids on the upper and lower sides thereof, and after supplying hydraulic oil to the inside, covers the piston member 51b on the interface of the hydraulic oil. It is configured to be placed as a body.

[Eighth Embodiment] An eighth embodiment will be described with reference to FIG.
This will be described in detail with reference to FIG. First, the core controller 39
Are a core circuit 41 and a pressure / flow control circuit 42 for generating hydraulic pressure.
It is composed of The core circuit 41 includes a limit switch 37 (37a, 37b), a core cylinder 38, a piston rod 43, a piston 44, and a slide core 2.
2 and a direction switching valve 46 and a check valve 54. Further, the hydraulic pressure generation / flow control circuit 42 includes a servomotor 50, a hydraulic oil tank 51, a piston pump 70, and a relief valve 74.

Hydraulic oil is supplied to the core cylinder 38, and a hydraulic oil tank 51 is provided as a supply source.
A piston pump 70 for supplying hydraulic oil from the hydraulic oil tank 51 to the core cylinder 38 via the circulation path m
Is provided. The piston pump 70 is directly connected to the servomotor 50, and rotates the servomotor 50 to rotate the piston pump 70.

The hydraulic oil tank 51 and the piston pump 70 are connected by a flow path m. A flow path s is provided so as to branch from the space between the piston pump 70 and the check valve 54 to the hydraulic oil tank 51. I have. Further, a relief valve 74 is interposed in the distribution path s, and the distribution paths m, o, p
When the pressure between them rises, it falls below a certain pressure. Further, a check valve 54 and a direction switching valve 46 are interposed in the flow paths n, o, and p between the piston pump 70 and the core cylinder 38, and are connected to the hydraulic oil tank 51 by switching the direction switching valve 46. It is supposed to be.

In the illustrated example, when the slide core 22 is advanced by advancing the piston 44 of the core device, if the solenoid valve of the direction switching valve 46 is excited and switched while the piston pump 70 is rotated, the hydraulic oil flows. Path m, n, o, p
Through the core cylinder 38 to the head side of the piston 44.

On the other hand, when the slide core 22 is moved backward, the direction switching valve 46 is kept rotating the piston pump 70.
When the electromagnetic valve is excited and switched, hydraulic oil is introduced from the hydraulic oil tank 51 to the rod side of the piston 44 of the core cylinder 38 via the flow paths m, n, o, and q.
The hydraulic fluid 4 is retracted and the hydraulic oil stored on the piston head side is discharged to the hydraulic oil tank 51 via the flow paths p and r. Reference numerals 37a and 37b denote limit switches, 37a denotes a forward limit switch, and 37b denotes a backward limit switch.

The molding operation of the core control device of the molding machine configured as described above will be described. First, in the state shown in FIG. 7, after the fixed mold 3 and the movable mold 4
The operation of the core control device 39 is started. Until then, the slide core 22 is at the retreat limit position most retracted from the cavity 32. First, in the suction operation, the solenoid valve of the direction switching valve 46 is excited to bring the core cylinder 38 and the hydraulic oil tank 51 into communication. When the piston pump 70 is rotated, hydraulic oil is supplied from the hydraulic oil tank 51 to the head side of the piston 44 of the core cylinder 38 through the flow paths m, n, o, and p. When hydraulic oil is introduced to the head side of the piston 44 of the core cylinder 38 and the piston rod 43 of the piston 44 advances, the forward limit switch 3
By kicking 7a, the slide core 22 stops at the forward limit.

After that, the servo motor 12 is switched to a very low speed and high torque rotation to generate a predetermined final clamping force. When a predetermined cooling time elapses after the molten resin is injected into the cavity 32, the servomotor 12 reversely rotates to open the two dies 3, 4. Cavity 3
First, the slide core 22 is retracted in order to remove the slide core 22 from the slide core 22, which is performed as follows. That is, after the slide core 22 is advanced to the forward limit as described above, the molten resin is injected into the cavity 32, and then the holding pressure and cooling of the mold are completed, and the solidification of the injected and filled resin is completed. The servomotor 50 which has been advanced in order to move the piston 44 of the core cylinder 38 to the forward limit while opening 3 and 4 is rotated, and the piston 52 is retracted to the retract limit.

In order to remove the cooled and solidified molded product from the cavity 32, an excitation signal is output to the direction switching valve 46, and the piston pump 70 and the piston rod 43 side of the core cylinder 38 are in communication. At this time, when the piston 44 of the piston 44 retreats, the slide core 22 stops at the retreat limit by kicking the retreat limit switch 37b. As a result, the molded product from which the undercut portion has been caught is removed from the push rod 34 because the movable mold 4 is retracted by a predetermined amount and is in the mold open state.
Is activated, the ejector plate 24, the ejector pin 3
The molded product is pushed down from the movable mold 4 through the “0”.

[0089]

As described above, according to the present invention,
When the electric drive is used as the drive source on the mold clamping side and the injection side, and the hydraulic drive is used as the drive source for the core device, the control is performed in comparison with the conventional case where the mold clamp side and the injection side are also hydraulic. The circuit is simplified. In addition, since an electric control motor such as a servo motor or a linear motor is driven only when the core device is in operation, energy is saved, and 2.5 times the rated output can be output in a short time. It has many advantages, such as being able to reduce the number of times. Further, by making the hydraulic oil tank a closed type, air does not get caught in the operating pressure oil during operation.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an embodiment of a mold clamping device of an injection molding machine according to the present invention.

FIG. 2 is a cross-sectional view of a main part when a molded product is obtained by injecting a molten resin into a cavity.

FIG. 3 is a configuration diagram of a core control device according to the first embodiment.

FIG. 4 is a configuration diagram of a core control device according to a second embodiment.

FIG. 5 is a configuration diagram of a core control device according to a third embodiment.

FIG. 6 is a configuration diagram of a core control device according to a fourth embodiment.

FIG. 7 is a configuration diagram of a core control device according to a fifth embodiment.

FIG. 8 is a configuration diagram of a core control device according to a sixth embodiment.

FIG. 9 is a configuration diagram of a core control device according to a seventh embodiment.

FIG. 10 is a configuration diagram of a core control device according to an eighth embodiment.

FIG. 11 is a configuration diagram of a conventional core control device.

[Explanation of symbols]

2 ... fixed die plate 3 ... fixed mold 4 ... movable mold 5 ... movable die plate 6 ... tie bar 7 ... ball screw shaft 9 ... rotating body 12 ... servo motor 13 ... timing belt 16 ... heating cylinder 22 ... slide core 24 ... Ejector plate 26 ... Spacer block 28 ... Support member 30 ... Ejector pin 32 ... Cavity 37 ... Limit switch 37a ... Forward limit switch 37b ... Retreat limit switch 38 ... Core cylinder 39 ... Core controller 40 ... Core device 41 ... Core circuit 42 ... Hydraulic pressure generating pressure / flow control circuit 44 ... Piston 46 ... Direction switching valve 47 ... First switching valve 48 ... Actuator 50 ... Servo motor 51 ... Hydraulic oil tank 52 ... Piston 53 ... Cylinder 54 ... Check Valve 55 Belt 56 Supply / discharge port 58 Direction switching valve 60 First direction Exchange valve 62 ... Closed hydraulic cylinder 64 ... Linear motor 66 ... Compression member 68 ... Liquid storage chamber 70 ... Piston pump 72 ... Expansion member 74 ... Relief valve 80 ... Hydraulic core control device 90 ... Pressure / flow control circuit 91 ... Oil tank 92: Hydraulic oil 110: Core circuit 120: Core cylinder a, b, c, d, e, f, g, h, i, j, m, n,
o, p ... distribution channel

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 4F202 AR02 CA11 CB01 CK32 CK54 CK74 CL22 CL38 4F206 AR02 JA07 JL02 JM06 JN41 JQ81 JT06 JT21 JT34

Claims (11)

[Claims] The present invention relates to a core control device provided in a molding machine having an electric mold clamping device for converting the rotational force of a servomotor into a thrust required for mold clamping operation by a nut and a ball screw shaft. A hydraulically driven core cylinder is arranged in a fixed mold or a movable mold, and a slide core is provided at the end of the core cylinder, which enables molding of a product having a portion which can move forward and backward and has an undercut. An oil path is provided between the core cylinder and the oil tank, and another electric control motor different from the servomotor of the electric mold clamping device is used as a drive source for operating the oil tank to the core cylinder. An actuator capable of supplying pressurized oil is provided, and further, valve means for switching an oil path provided between the actuator and the core cylinder is provided, and the oil path is switched by switching the valve means. Core control device of the molding machine, characterized by comprising a structure for performing supply and discharge of hydraulic pressure oil between the actuator and the core cylinder. 2. The actuator according to claim 1, wherein the actuator is provided with an oil supply cylinder at one end of a ball screw shaft capable of moving forward and backward in accordance with transmission of a rotational force of a servo motor forming the electric control motor, and the oil path. A switching valve means is provided between the first switching valve and the core cylinder, the first switching valve being capable of supplying and discharging oil from the oil tank to the core cylinder via the oil supply cylinder. 2. The core control device for a molding machine according to claim 1, further comprising a direction switching valve capable of supplying said operating pressure oil from said oil supply cylinder to said core cylinder by switching. 3. The actuator is provided with an oil supply cylinder at one end of a ball screw shaft capable of moving forward and backward in accordance with transmission of a rotational force of a servo motor forming the electric control motor, and the oil path. The switching valve means is provided between the refueling cylinder and the core cylinder and in the order of proximity to the refueling cylinder in the order from the first directional switching valve to the second directional switching valve.
A direction switching valve is arranged, and switching of the first direction switching valve and the second direction switching valve enables supply of pressurized oil from the oil tank to the core cylinder via the oil supply cylinder, or 2. The core control device for a molding machine according to claim 1, wherein a run-around circuit can be formed in said hydraulic cylinder by switching only said first direction switching valve. 4. A check valve is provided between the first directional control valve and the directional control valve or between the first directional control valve and the second directional control valve. The core control device of the molding machine described in the above. 5. The actuator according to claim 1, wherein the actuator includes an oil supply cylinder at one end of a ball screw shaft capable of moving forward and backward in accordance with transmission of a rotational force of a servo motor forming the electric control motor, and the oil path. The switching valve means includes a single direction switching valve disposed between the refueling cylinder and the core cylinder, and is configured to switch between the oil tank and the oil tank via the refueling cylinder by switching the direction switching valve. 2. The core control device for a molding machine according to claim 1, wherein a pressure oil can be supplied to and discharged from said core cylinder. 6. The actuator is provided with a hermetically sealed hydraulic cylinder having therein a moving member that moves forward and backward by a linear motor forming the electric control motor,
The valve means for switching the oil path is configured by arranging a second directional switching valve following the first directional switching valve in an order closer to the closed hydraulic cylinder between the closed hydraulic cylinder and the core cylinder, By switching between the first directional switching valve and the second directional switching valve, it is possible to supply pressurized oil from the oil tank to the core cylinder via the closed hydraulic cylinder, or only the first directional switching valve. 2. A core control device for a molding machine according to claim 1, wherein a run-around circuit can be formed in said closed hydraulic cylinder by switching. 7. The actuator according to claim 1, wherein the actuator includes a piston pump rotated by a servo motor forming the electric control motor, and the oil path switching valve means is provided between the piston pump and the core cylinder. A direction switching valve is arranged, and by switching the direction switching valve, oil from the oil tank can be supplied to and discharged from the core cylinder via the piston pump and the direction switching valve. The core control device of a molding machine according to claim 1, wherein: 8. An oil tank for storing the operating pressure oil,
The core control device for a molding machine according to any one of claims 1 to 7, wherein a partition is formed by an elastic member, and the enclosed space is filled with oil. 9. An oil tank for storing the operating pressure oil,
The core control device of a molding machine according to any one of claims 1 to 7, wherein the closed space is filled with oil by using a piston member as a partition. 10. The actuator according to claim 1, wherein the actuator includes a piston pump that is rotated by a servomotor forming the electric control motor, and the oil path switching is performed by a direction switching valve disposed between the piston pump and the core cylinder. The relief means is arranged in the middle of the oil path between the direction switching valve and the piston pump. By switching the direction switching valve, oil from the oil tank is supplied to the piston pump and the direction switching valve. 2. The core control device for a molding machine according to claim 1, wherein the core can be supplied / discharged to / from the core cylinder. 11. A mold clamping is performed by using a rotation / linear conversion mechanism that converts a rotational force of a servomotor into a thrust necessary for mold clamping operation of a mold by a nut and a ball screw shaft. A core control method for a molding machine, comprising a fixed cylinder or a movable mold provided with a core cylinder that hydraulically drives a member and enabling molding of a product having a part to be undercut, wherein the core member is driven. Via an oil path provided between the core cylinder and the oil tank, the actuator from the oil tank to the core cylinder is operated by an actuator using another electric control motor different from the servo motor for mold clamping as a drive source. At this time, the pressure oil is supplied, and at this time, the actuator and the medium through the oil path are switched by switching an oil path switching valve means provided between the actuator and the core cylinder. Controlling the supply and discharge of the operating pressure oil to and from the slave cylinder; controlling the forward speed of the core cylinder by the speed of the electric control motor; A core control method for a molding machine, wherein a maximum hydraulic pressure related to the operating pressure oil supplied to a child cylinder is controlled.