JP3168888B2 - Hydraulic machine operation control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hydraulic machine operation restricting device for restricting the operation of a hydraulic machine during maintenance work or the like.

[0002]

2. Description of the Related Art As a hydraulic machine using hydraulic pressure, for example,
There is an injection molding machine for plastic products that opens and closes a mold by hydraulic pressure. Such an injection molding machine is generally provided with a safety door, and when the safety door is opened during maintenance work or the like, an operation restricting device is provided so that the mold does not move in the closing direction. Is provided. As shown in FIG. 7, the injection molding machine includes a pump 8 for generating hydraulic pressure.
0, a transmission circuit 81 for transmitting the hydraulic pressure generated by the pump 80, and a hydraulic cylinder (operating unit) 8 which is moved forward and backward by the hydraulic pressure transmitted by the transmission circuit 81 to open and close the mold.
An electromagnetic switching valve 83 provided in the middle of the transmission circuit 81 for communicating the transmission circuit 81, and switching the hydraulic cylinder 82 so that the hydraulic cylinder 82 moves forward, backward, or stops by the electromagnetic force; As the operation restricting device, when the safety door 84 shown in (a) is opened, the mold is regulated to prevent the hydraulic cylinder 82 from moving forward, and the safety door 84 shown in (b) is closed. In this state, a switching valve 85 that allows the hydraulic cylinder 82 to move forward and backward is provided separately in the transmission circuit 81. The switching valve 85 is switched in conjunction with the opening / closing operation of the safety door 84, and when the safety door 84 is in an open state, the transmission circuit 81 transmits hydraulic pressure on the forward side of the hydraulic cylinder 82 by the transmission circuit 81 regardless of the electromagnetic switching valve 83. Is being cut off.

[0003]

The above-mentioned operation restricting device is
Since the switching valve is provided separately from the electromagnetic switching valve, the pressure loss of the hydraulic pressure is increased by the amount of the switching valve, and the performance such as the speed of the hydraulic cylinder is reduced. For this reason, there is a problem that a pump having a high capacity, that is, a large pump must be used by the amount of the loss, and the cost is greatly increased. In addition, there is a problem that the frequency of failures increases because the number of parts increases.
Therefore, an object of the present invention is to provide an operation restriction device for a hydraulic machine that can minimize an increase in cost and prevent an increase in the frequency of failure.

[0004]

SUMMARY OF THE INVENTION According to the present invention, there is provided a hydraulic machine operation restricting apparatus comprising: a pump for generating hydraulic pressure; a transmission circuit for transmitting hydraulic pressure generated by the pump; and a hydraulic circuit transmitted by the transmission circuit. An actuating part to be actuated, a box in which an internal flow path constituting a part of the transmission circuit is formed, and a spool movably provided in the box and moved by electromagnetic force to switch the internal flow path a hydraulic machine having a, an electromagnetic switching valve having bets, input from the safety door
Lever that swings with the lever, and swings with the input from the safety door
A movement restricting means having a pin pressed by the lever and protruding into the box body to restrict the movement of the spool is provided. This allows the movement restricting means to protrude into the box of the electromagnetic switching valve to restrict the movement of the spool, thereby restricting the switching of the transmission flow path, that is, the operation of the operating section of the hydraulic machine.

[0005]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One example of an embodiment of the operation restricting device for a hydraulic machine according to the present invention will be described below with reference to FIGS. Here, a case where the hydraulic machine is an injection molding machine made of plastic or the like that opens and closes a mold by hydraulic pressure will be described as an example. In FIG. 1, reference numeral 11 denotes a hydraulic cylinder (operating unit) for moving a movable mold (not shown) provided movably relative to a fixed mold (not shown) having a fixed position to separate and approach the movable mold.

[0006] The hydraulic cylinder 11 comprises a cylinder body 1.
2 is partitioned into a first chamber 14 and a second chamber 15 by a piston 13. When hydraulic pressure is introduced into the first chamber 14 and hydraulic pressure is released from the second chamber 15, the piston 13 is advanced to move forward. The movable mold connected to the piston 13 is brought close to the fixed mold, and the mold is closed. On the other hand, the hydraulic pressure is introduced into the second chamber 15 and the hydraulic pressure is released from the first chamber 14, whereby the piston 13 is retracted, and the movable mold connected to the piston 13 is separated from the fixed mold to remove the mold. Leave open.

In FIG. 1, reference numeral 17 denotes a pump for generating hydraulic pressure, reference numerals 18a to 18d denote transmission circuits for transmitting the hydraulic pressure generated by the pump 17, reference numeral 19 denotes a tank for releasing the hydraulic pressure, and reference numeral 20 denotes a transmission circuit. The solenoid-operated switching valves provided at 18a to 18d are shown.

The electromagnetic switching valve 20 has a first port 22a connected to a transmission circuit 18a connected to the first chamber 14 of the hydraulic cylinder 11, and a second port 22a connected to a transmission circuit 18b connected to the discharge side of the pump 17. Two ports 22b, a third port 22c connected to a transmission circuit 18c connected to the second chamber 15 of the hydraulic cylinder 11, and a tank 1 for releasing hydraulic pressure
9 having a fourth port 22d connected to a transmission circuit 18d connected to the transmission circuit 9 (a part of the transmission circuit) 22
Is formed at the center and has a box body 25 having coaxial spaces 23 and 24 arranged on both sides of the internal flow path 22. The solenoid-operated switching valve 20 is provided substantially movably corresponding to the position where the internal flow path 22 is formed in the box 25, and is provided with a spool 27 for switching the ports 22 a to 22 d of the internal flow path 22. , 24 and coaxially disposed with the spool 27 so as to be freely movable and abutted to respective ends of the spool 27 in the axial direction, and coaxial outer sides of the respective sliders 28 and 29. And springs 3 arranged on both sides in the axial direction of the spool 27 to uniformly urge the spool 27 from both sides.
2, 33. Further, through holes 34, 3 penetrating from the spaces 23, 24 to the outside at both ends of the box 25.
5 are formed coaxially with the spaces 23 and 24, respectively.
38 are movably fitted. The pin 37 has a cylindrical shaft portion 37a and a head portion 37b having a larger diameter than the shaft portion 37a, and the shaft portion 37a is inserted into the through hole 34, and the head portion 37b is disposed in the space 23. Similarly, the pin 38 has a cylindrical shaft portion 38a and a head portion 38b having a larger diameter than the shaft portion 38a.
And the head 38 b is disposed in the space 24.

Here, the spool 27 is provided with both electromagnetic coils 3
In a position where only the urging forces of the two springs 32 and 33 are applied when 0 and 31 are in a demagnetized state (hereinafter referred to as a neutral position), any one of the first port 22a to the fourth port 22d as shown in FIG. They are not in communication with each other. When the electromagnetic coil 31 is excited while the electromagnetic coil 30 is in the demagnetized state, as shown in FIG.
The spool 27 moves to a position (hereinafter referred to as a forward position) moved from the neutral position to the mover 28 side by the movement of the mover 29. In this forward position, the spool 27 has a state in which the first port 22a communicates with the second port 22b and the third port 22c communicates with the fourth port 22d. At this time, the moving element 28 is
3 comes into contact with the head 37b of the pin 37 which is in contact with the surface portion 23B on the end side. When the electromagnetic coil 30 is excited while the electromagnetic coil 31 is in the demagnetized state, as shown in FIG. 4, the mover 28 moves until it comes into contact with the surface 23A on the center side of the space 23. As a result of the movement of the spool 28, the spool 27 is moved to a position where the spool 27 is moved from the neutral position to the movable element 29 side (hereinafter referred to as a retracted position). In the retracted position, the spool 27 is connected to the first port 22a and the fourth port 22a.
d and the second port 22b and the third port 22c. At this time, the mover 29 contacts the head 38b of the pin 38 which is in contact with the surface 24B on the end side of the space 24.

In the present embodiment, when the spool 27 is in the forward position, the pin
7, a shaft portion 37a is formed so as to extend outside the box body 25 with the head portion 37b in contact with the surface portion 23B, and a roller is provided at one end on the end surface of the extended shaft portion 37a. 40
Is held in contact with the lever 41. The lever 41 is swung by a safety door 42. When the safety door 42 shown in FIGS.
0 is not input from the safety door 42,
Is in a state in which the head 37b can be moved to a position where it comes into contact with the surface portion 23B. In this state, the spool 2
Numeral 7 is movable to any of a neutral position, a forward position and a retreat position. On the other hand, when the safety door 42 is opened, as shown in FIG.
Swings in response to an input from the safety door 42 by being put on the roller 40, and presses the pin 37 to separate the head 37b from the surface 23B so as to protrude into the box 25, and the spool in the neutral position. 27 comes into contact with the moving element 28. In this state, the movement of the movable member 28 is restricted by the pin 37 protruding into the box 25, so that the movement of the spool 27 from the neutral position to the forward position is restricted. In this case, the lever 41 and the pin 37 protrude into the box 25 and constitute a movement restricting means for restricting the movement of the spool 27.

Thus, when the safety door 42 is opened during a maintenance operation or the like, the lever 41, which is the movement restricting means, is swung by the safety door 42, and the pin 37, which is also the movement restricting means, is moved into the box 25. By controlling the movement of the spool 27 by protruding, the switching of the transmission channels 18a to 18d, that is, the operation of the hydraulic cylinder 11 of the injection molding machine, which is a hydraulic machine, can be regulated. Therefore,
Since there is no need to provide a switching valve separately from the electromagnetic switching valve 20, the pressure loss of the hydraulic pressure is reduced, and the pump 17 can be used in the minimum necessary, so that the cost increase can be minimized. At the same time, it is possible to prevent the number of parts from being reduced and the frequency of failure from increasing.

Here, specifically, in this example, the spool 2
7 Because the movement from the neutral position to the forward position is regulated,
The movement of the hydraulic cylinder 11 in the forward direction, that is, the movement of the movable mold in the closing direction close to the fixed mold is restricted. On the other hand, since the movement of the spool 27 from the neutral position to the retracted position is not restricted, the retracting operation of the hydraulic cylinder 11, that is, the movement of the movable mold in the separating and opening direction from the fixed mold is not restricted.

The above example can be modified as follows. As shown in FIG. 5, the box 2 of the electromagnetic switching valve 20
5, a support portion 44 is integrally provided, and the support portion 44 swingably supports the lever 41. A locking portion 37 having a larger diameter than the shaft portion 37a is provided on the side of the pin 37 protruding from the box 25.
c, a spring 45 is provided between the locking portion 37c and the box 25, and the head 37b of the pin 37 is always in contact with the surface 23B when there is no input from the safety door 42. And

Further, as shown in FIG.
When the retractor is in the retracted position, the pin 38 on the side to which the mover 29 approaches also extends out of the box body 25 with the head 38b in contact with the surface 24B of the space 24.
a, and a lever 41 is provided on the end face of the extended shaft portion 38a.
And a lever 48 which is connected to the lever 41 via a connecting arm 47 and swings together with the lever 41. This lever 48
Is swung by a safety door 42 together with a lever 41. When the safety door 42 is closed, the safety door 4
There is no input from the lever 2 to the roller 40 of the lever 41. At this time, the head 38b of the pin 38 is
It is in a state where it can be moved to a position where it contacts B. In this state, the spool 27 can move to any of the forward position and the backward position. On the other hand,
When the safety door 42 is opened and the input from the safety door 42 by the
Swings in the same manner as described above, the lever 48 swings in conjunction with the lever 41, and pushes the pin 38 to move the head 38b.
Is separated from the surface portion 24 </ b> B so as to project into the box 25, and comes into contact with the movable element 29 that contacts the spool 27 at the neutral position. In this state, the movement of the movable element 29 is restricted by the pin 38 protruding into the box 25, so that the movement of the spool 27 from the neutral position to the retracted position is restricted. The movement of the movable member 28 on the side is also restricted to the forward position by the pin 37 protruding into the box 25, so that the movement of the spool 27 in any direction from the neutral position to the forward position and the retracted position is restricted. Will be. In this case, lever 41,
Connecting arm 47, lever 48, pin 37 and pin 38
Constitute a movement restricting means that protrudes into the box 25 and restricts the movement of the spool 27.

In this example, since the movement of the spool 27 from the neutral position to the forward position and the movement from the neutral position to the backward position are both regulated, the forward operation and the backward operation of the hydraulic cylinder 11, that is, the movable mold Both the movement in the close direction toward the fixed mold and the movement in the open direction away from the fixed mold are both regulated.

[0016]

As described above in detail, according to the operation restricting device for a hydraulic machine of the present invention, the movement restricting means projects into the box body of the electromagnetic switching valve to restrict the movement of the spool, so that the transmission flow path can be controlled. , That is, the operation of the operating section of the hydraulic machine. Therefore, since there is no need to provide a switching valve separately from the electromagnetic switching valve, the pressure loss of the hydraulic pressure is reduced, and the pump can be used in the minimum necessary, so that the cost increase can be minimized. At the same time, it is possible to prevent the number of parts from being reduced and the frequency of failure from increasing.

[Brief description of the drawings]

FIG. 1 is a hydraulic circuit diagram showing an example of an embodiment of an operation restricting device for a hydraulic machine according to the present invention, which is a hydraulic circuit diagram in section of an electromagnetic on-off valve, in which movement is restricted by a movement restricting means and a spool is in a neutral position. It shows the status.

FIG. 2 is a hydraulic circuit diagram showing an example of an embodiment of an operation restricting device for a hydraulic machine according to the present invention, in which a solenoid on-off valve is sectioned, and a spool is in a neutral position without movement being restricted by movement restricting means. Is shown.

FIG. 3 is a hydraulic circuit diagram showing an example of an embodiment of an operation restricting device for a hydraulic machine according to the present invention, which is a sectional view of an electromagnetic on-off valve, in which a spool is moved to a forward position without being restricted by a movement restricting means. Is shown.

FIG. 4 is a hydraulic circuit diagram showing an example of an embodiment of an operation restricting device for a hydraulic machine according to the present invention, which is a sectional view of an electromagnetic on-off valve, in which a movement is restricted by a movement restricting means, and a spool is in a retracted position. Is shown.

FIG. 5 is a hydraulic circuit diagram in section of an electromagnetic on-off valve showing another embodiment of the hydraulic machine operation restricting device according to the embodiment of the present invention, wherein the movement is not restricted by the movement restricting means; This shows the state in the neutral position.

FIG. 6 is a hydraulic circuit diagram showing a cross section of an electromagnetic on-off valve showing still another embodiment of the operation restricting device for a hydraulic machine according to the present invention, wherein the movement is restricted by the movement restricting means and the spool is neutral. This shows the state at the position.

FIG. 7 is a hydraulic circuit diagram showing a conventional operation restricting device for a hydraulic machine.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 Hydraulic cylinder 17 Pump 18a-18d Transmission circuit 20 Solenoid switching valve 25 Box 27 Spool 37,38 Pin (movement restricting means) 41,48 Lever (movement restricting means) 47 Connecting arm (movement restricting means)

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) F16K 31/06-31/11 F16K 35/00 F15B 13/044 F15B 20/00

Claims (1)

(57) [Claims] 1. A pump that generates hydraulic pressure, a transmission circuit that transmits hydraulic pressure generated by the pump, an operating unit that is operated by the hydraulic pressure transmitted by the transmission circuit, and a part of the transmission circuit. An electromagnetic switching valve having a box body with an internal flow path formed therein and a spool movably provided in the box body and moved by electromagnetic force to switch the internal flow path. The lever that swings by the input from the safety door and the safety door
A movement restricting means having a pin that is pressed by the lever that swings by the input of the lever and protrudes into the box to restrict the movement of the spool. .