JP2010264468A - Molding machine and controller of the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a molding machine for securing safety and reducing working hours. <P>SOLUTION: A controller 51 of a die-cast machine selectively performs control in a normal mode and control in a special mode, when an accumulator 53 is in an unfilled state and a pump 33 is in a stoppage state. The controller 51 in the normal control mode fills up the accumulator 53 with the pump 33 (step ST4), and then drives any one of at least one or more cylinder units with the accumulator 53 or pump 33. The controller 51 in the special control mode intercepts a flow from the pump 33 to the accumulator 53, and drives any one of at least one or more cylinder units with the pump 33, while the accumulator 53 remains in the unfilled state. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a molding machine such as a die casting machine and a control device for the molding machine.

  A technique using a hydraulic device such as a hydraulic device as a driving device of a molding machine such as a die casting machine is known (for example, Patent Document 1). In such a molding machine, an operator may perform an operation such as visually confirming the mounting state of the mold and the state of applying the release agent before or during the start of the molding cycle. That is, the worker may perform an operation of opening the door of the molding machine or entering the molding machine (hereinafter, such operations are collectively referred to as “entry operation”). At this time, in order to ensure safety, the hydraulic device of the molding machine is in a state where the driving force is not exhibited. Specifically, the motor that drives the pump is stopped, and the working fluid in the accumulator (may be abbreviated as “ACC” in the drawings and the like) is discharged to the tank.

  In addition, after the entry work, there is a case where an operation of driving each part of the molding machine by the hydraulic device to confirm the operation of the molding machine (hereinafter, referred to as “confirmation work”) may be performed. That is, the motor that drives the pump is restarted and the accumulator is filled. Various cylinder devices are driven by a pump or the like, and members such as a die plate, an injection plunger, and an extrusion pin are driven. Further, the entry work and the confirmation work may be repeatedly performed.

JP 2003-74505 A

  However, it takes a relatively long time until the hydraulic device including the accumulator and the like is filled with the hydraulic fluid and the cylinder device can be driven after the start of the pump is instructed. Therefore, if the approach operation and the confirmation operation are repeated, the operation time until the start or restart of the molding cycle is prolonged.

  An object of the present invention is to provide a molding machine and a molding machine control apparatus capable of shortening the operation time while ensuring safety.

  The molding machine of the present invention includes an accumulator, a pump capable of filling the accumulator, one or more cylinder devices driven by the accumulator or hydraulic fluid from the pump, the accumulator, the pump, and the one or more cylinders. A hydraulic circuit that controls the flow of hydraulic fluid between the devices, and a control device that controls the pump and the hydraulic circuit, wherein the control device is in an unfilled state of the accumulator, and When the pump is in a stopped state, control in the first mode and control in the second mode can be selectively performed. In the control in the first mode, the accumulator is filled by the pump, and then , At least one of the one or more cylinder devices can be driven by the accumulator or the pump; In the control blocks the flow from the pump to the accumulator, while the accumulator with the unfilled state, can be driven at least one of the one or more cylinder units by the pump.

  Preferably, the molding machine further includes a rotary electric motor that drives the pump, and the control device switches the control to be executed to the control of the first mode during the execution of the control of the second mode. When the control of the first mode or the second mode is started when the accumulator is in an unfilled state and the pump is in a stopped state, the motor is started by starting the motor. When the driving of the pump is started and the control to be executed is switched to the control of the first mode during the execution of the control of the second mode, the control of the first mode is started while maintaining the rotation of the electric motor, The pump starts filling the accumulator.

  Preferably, the one or more cylinder devices include an injection cylinder device that drives an injection plunger to inject a molding material into a cavity when hydraulic fluid is supplied from the accumulator, and the control device includes the first cylinder device. In the control in the first mode, the injection cylinder device can be driven by the accumulator, and in the control in the second mode, the injection cylinder device can be driven by the pump.

  Preferably, the hydraulic circuit includes a first valve capable of allowing or prohibiting a flow of hydraulic fluid from the pump to the accumulator, and an operation from the accumulator to at least one of the one or more cylinder devices. A second valve capable of permitting or prohibiting a flow of liquid, and one or more third valves capable of permitting or prohibiting a flow of hydraulic fluid from the pump to the one or more cylinder devices.

  The control device of the molding machine according to the present invention includes an accumulator, a pump capable of filling the accumulator, one or more cylinder devices driven by the accumulator or hydraulic fluid from the pump, the accumulator, the pump, and the 1 A hydraulic pressure circuit that controls the flow of hydraulic fluid between the cylinder devices, and a control device that controls the pump and the hydraulic pressure circuit, wherein the accumulator is in an unfilled state. And when the pump is in a stopped state, the control in the first mode and the control in the second mode can be selectively executed. In the control in the first mode, the accumulator is operated by the pump. After filling, at least one of the one or more cylinder devices can be driven by the accumulator or the pump. Thus, in the control in the second mode, the flow from the pump to the accumulator is interrupted, and at least one of the one or more cylinder devices can be driven by the pump while the accumulator is not filled. It is.

  According to the present invention, it is possible to shorten the work time while ensuring safety.

The figure which shows the outline | summary of the principal part of the die-casting machine which concerns on embodiment of this invention. The typical top view which shows the die-casting machine of FIG. 1 including an exterior part. The figure which shows the structure of the hydraulic apparatus of the die-casting machine of FIG. The figure which shows the structure which concerns on the injection cylinder apparatus of the hydraulic apparatus of FIG. The figure which shows the time-dependent change of the injection speed and injection pressure of the die-casting machine of FIG. The figure which shows the time-dependent change of the pressure of the hydraulic fluid in each control mode. The flowchart which shows the procedure of the process which the control apparatus of the die-casting machine of FIG. 1 performs.

<Die-casting machine configuration>
FIG. 1 is a side view showing a main part of a die casting machine 1 according to an embodiment of the present invention.

  The die casting machine 1 holds a main mold 101 including a fixed mold 103 and a movable mold 105, and a mold clamping device 3 that opens and closes and molds the main mold 101 and a core 107 are put in and out of the main mold 101. The core drawing device 5, the injection device 7 for injecting and filling molten metal (a molten metal material) as a molding material into the cavity Ca formed in the main mold 101, and the molten metal filled in the cavity Ca are solidified. It has the extrusion apparatus 9 which extrudes the formed molded article from the fixed mold 103 or the moving mold 105 (in FIG. 1, the moving mold 105).

  The mold clamping device 3 is constituted by, for example, a toggle type mold clamping device, and includes a fixed die plate 11 that holds the fixed mold 103, a movable die plate 12 that holds the movable mold 105, and a movable die plate 12. The link housing 13 disposed on the opposite side of the fixed die plate 11, the plurality of tie bars 14 hung on the fixed die plate 11 and the link housing 13, and the mold clamping cylinder device provided in the link housing 13 15 and a toggle mechanism 17 for transmitting the driving force of the mold clamping cylinder device 15 to the movable die plate 12. When the driving force of the mold clamping cylinder device 15 is transmitted to the movable die plate 12 via the toggle mechanism 17, the movable die plate 12 moves in the mold opening / closing direction (left and right direction in FIG. 1), Clamping is performed.

  The core drawing device 5 includes a core cylinder device 19 that drives the core 107. In the core cylinder device 19, for example, a cylinder tube is fixed to the moving mold 105 and a piston rod is fixed to the core 107. In addition, the core extraction apparatus 5 may have an inclined pin or the like.

  The injection device 7 includes, for example, a sleeve 21 that communicates with the cavity Ca, an injection plunger 23 that can slide within the sleeve 21, and an injection cylinder device 25 that drives the injection plunger 23. The molten metal is supplied into the sleeve 21 by a ladle (not shown) and the injection plunger 23 moves forward in the sleeve 21 toward the cavity, whereby the molten metal is injected and filled into the cavity Ca.

  The extruding device 9 has an extruding pin 27 that extrudes the molded product through the movable mold 105 from behind, and an extruding cylinder device 29 that drives the extruding pin 27. In the extrusion cylinder device 29, the cylinder tube is fixed to the moving mold 105, and the piston rod is fixed to the extrusion pin 27. In the extrusion device 9, the cylinder tube may be fixed to the extrusion pin and the piston rod may be fixed to the moving mold 105.

  FIG. 2 is a schematic plan view showing the die casting machine 1 including the exterior portion 95.

  The exterior portion 95 is provided for the purpose of preventing an operator from approaching the movable portion of the die casting machine 1. The exterior part 95 is formed, for example, in a wall shape standing on the side of the mold clamping device 3. The exterior portion 95 has a door 97 so that an operator can visually observe the main mold 101 or enter between the die plates. For example, the door 97 is slidably provided between a closed position (indicated by a solid line) facing between the die plates and an open position (indicated by a two-dot chain line) retracted from the closed position to the movable die plate 12 side. It has been.

  An operation panel 99 for an operator to operate the die casting machine 1 is provided at a position adjacent to the closed position of the door 97. The operation panel 99 includes, for example, an input device 91 (see FIG. 4) and a display device 92 (see FIG. 4). The input device 91 includes, for example, an operation member such as a dial and a push button, and a switch operated by the operation member, although not particularly illustrated.

  FIG. 3 is a diagram showing an outline of the configuration of the hydraulic device 30 including various cylinder devices (the mold clamping cylinder device 15, the core cylinder device 19, the injection cylinder device 25, and the extrusion cylinder device 29). In FIG. 3, for convenience of illustration, the tank 39 is shown in two places.

  The mold clamping cylinder device 15, the core cylinder device 19 and the extrusion cylinder device 29 are constituted by a single-acting cylinder device, and a cylinder tube (15t etc. is attached with an additional code t to the code of each cylinder device). ), A piston slidably accommodated in a cylinder tube (15p and the like, each cylinder device is indicated by an additional symbol p), and a piston rod (15r and the like each cylinder fixed to the piston) The device code is indicated with an additional symbol r).

  The cylinder chamber inside the cylinder tube is divided into a piston-side rod-side chamber (15a, etc., with an additional symbol a added to the code of each cylinder device) and a head-side chamber (15b, etc.) on the opposite side. The cylinder device is divided into a code and an additional code b). The mold clamping cylinder device 15, the core cylinder device 19 and the extrusion cylinder device 29 are driven by selectively supplying hydraulic fluid (for example, oil) to the head side chamber and the rod side chamber.

  The injection cylinder device 25 is composed of, for example, a direct-coupled pressure increasing cylinder, and includes a piston rod 25r fixed to the injection plunger 23, an injection piston 25p fixed to the piston rod 25r, and an injection piston 25p. It has a pressure-increasing piston 25pp disposed behind, and a cylinder tube 25t that slidably accommodates the injection piston 25p and the pressure-increasing piston 25pp.

  The piston rod 25r is connected coaxially with the injection plunger 23 via, for example, a coupling 31 (FIG. 1). The piston rod 25r may be fixed to the injection plunger 23 by being formed integrally with the injection plunger 23. The injection piston 25p is fixed to the rear end of the piston rod 25r. The piston rod 25r and the injection piston 25p may be separately formed and fixed, or may be fixed by being integrally formed.

  The cylinder tube 25t has a tube small-diameter portion 25ta on which the injection piston 25p slides, and a tube large-diameter portion 25tb that is continuous with the rear end of the tube small-diameter portion 25ta and has a larger diameter than the tube small-diameter portion 25ta. . The pressure-increasing piston 25pp has a piston small-diameter portion 25ppa that can slide the tube small-diameter portion 25ta and a piston large-diameter portion 25ppb that can slide the tube large-diameter portion 25tb.

  The cylinder chamber formed inside the small tube diameter portion 25ta is partitioned by the injection piston 25p into a rod side chamber 25a on the piston rod 25r side and a head side chamber 25b on the opposite side. The cylinder chamber formed inside the tube large diameter portion 25tb is divided into a front chamber 25c on the head side chamber 25b side and a rear chamber 25d on the opposite side by the piston large diameter portion 25ppb of the pressure increasing piston 25pp. .

  By supplying the working fluid to the head side chamber 25b, the injection piston 25p moves forward, and as a result, the injection plunger 23 moves forward toward the cavity Ca. When the hydraulic fluid is supplied to the rear chamber 25d, the pressure of the hydraulic fluid in the rear chamber 25d depends on the ratio of the pressure receiving area of the piston large diameter portion 25ppb to the pressure receiving area of the piston small diameter portion 25ppa by the pressure increasing piston 25pp. Then, the pressure is increased and transmitted to the head side chamber 25b. As a result, the molten metal in the cavity Ca is increased by the injection plunger 23.

  In the following, cylinder tubes, piston rods, pistons (injection pistons for the injection cylinder device 25), rod side chambers, and head side chambers of various cylinder devices (15, 19, 25, and 29) are denoted by additional symbols (t, r). , P, a, b) (for example, “piston rod r”) may not be distinguished between various cylinder devices.

  The die casting machine 1 controls the flow of the hydraulic fluid from the pump 33 to the various cylinder devices, the pump 33, the motor (electric motor) 35 for driving the pump 33, in order to supply the hydraulic fluid to the various cylinder devices. The hydraulic circuit 37 is provided.

  The pump 33 may be a rotary pump that discharges hydraulic fluid by rotation of a rotor such as a gear pump or a vane pump, or the hydraulic fluid is discharged by reciprocation of a piston such as an axial plunger pump or a radial plunger pump. A plunger pump may be used. Further, the pump 33 may be a fixed capacity pump or a variable capacity pump in which the discharge amount in one cycle of movement of the rotor or piston may be variable. The pump 33 only needs to be able to discharge the hydraulic fluid in one direction, but the structure may be the same as that of the bidirectional (two-way) pump.

  For example, the pump 33 sucks and discharges the hydraulic fluid stored in the tank 39 through the filter 41. On the discharge side of the pump 33, for example, a first check valve 57 that allows the flow of hydraulic fluid from the pump 33 to various cylinder devices and prohibits the flow in the opposite direction is provided.

  Although not particularly illustrated, the motor 35 includes a stator that constitutes one of a field and an armature, and a rotor that constitutes the other of the field and the armature and rotates with respect to the stator. The motor 35 may be a direct current motor or an alternating current motor. The motor 35 is constituted by a servo motor, for example. That is, the motor 35 is provided with a motor sensor 43 such as an encoder that detects the rotation of the motor 35, and the motor is driven by a servo driver (servo amplifier) 45 (see FIG. 4) based on the detection value of the motor sensor 43. 35 feedback control is performed.

  The hydraulic circuit 37 corresponds to various cylinder devices (15, 19, 25, and 29), the mold clamping side direction control valve 47A, the core side direction control valve 47B, the injection side direction control valve 47C, and the extrusion side direction. It has a control valve 47D (hereinafter simply referred to as “directional control valve 47”, which may not be distinguished).

  The direction control valve 47 can permit or prohibit the flow of hydraulic fluid from the pump 33 to various cylinder devices, and switches the supply destination of hydraulic fluid from the pump 33 between the rod side chamber a and the head side chamber b. Is possible. The direction control valve 47 is constituted by, for example, a 4-port 3-position switching valve. Specifically, it is as follows.

  The direction control valve 47 cuts off the connection between the pump 33 and the tank 39 and the head side chamber b and the rod side chamber a at the center position (neutral position) among the three positions indicated by the three rectangular symbols. Thereby, the supply of the hydraulic fluid from the pump 33 to the head side chamber b and the rod side chamber a is prohibited.

  The directional control valve 47 connects the pump 33 and the head side chamber b at the position on the left side of the paper (the right side of the paper in the injection cylinder device 25) among the three positions indicated by the three rectangular symbols, and the tank 39 and the rod The side chamber a is connected. When the hydraulic fluid is supplied to the head side chamber b by the pump 33, the piston p and the piston rod r advance in a direction protruding from the cylinder tube t. The hydraulic fluid in the rod side chamber a is pushed out by the piston p and flows into the tank 39.

  The directional control valve 47 connects the pump 33 and the rod side chamber a at the position on the right side of the paper (the left side of the paper in the injection cylinder device 25) among the three positions indicated by the three rectangular symbols, and the tank 39 and the head The side chamber b is connected. When the hydraulic fluid is supplied to the rod side chamber a by the pump 33, the piston p and the piston rod r move backward. The hydraulic fluid in the head side chamber b is pushed out by the piston p and flows into the tank 39.

  The direction control valve 47 is configured so that the position is switched when an electromagnetic control mechanism is operated, for example, and is switched according to an input electrical signal. The mold clamping side direction control valve 47A, the core side direction control valve 47B, and the extrusion side direction control valve 47D have only an electromagnetic control mechanism as a control mechanism, and the injection side direction control valve 47C has an electromagnetic type. The control mechanism may be appropriately configured according to required performance, such as a control mechanism in which the control mechanism and the hydraulic control mechanism sequentially operate.

  The pump 33 and the directional control valve 47 of various cylinder devices are connected by a flow path extending from the pump 33 branching corresponding to the various cylinder devices and reaching the directional control valve 47. Similarly, the tank 39 and the direction control valve 47 of various cylinder devices are connected by the flow path extending from the tank 39 branching corresponding to the various cylinder devices and reaching the direction control valve 47. . However, the flow path connecting the tank 39 and the direction control valve 47 of various cylinder devices may be formed individually in some cylinder devices or in all cylinder devices. In each cylinder device, a cooler 49 for cooling the hydraulic fluid is provided in a flow path through which the hydraulic fluid pushed out to the piston p flows to the tank 39.

  FIG. 4 is a diagram showing details of the configuration related to the injection cylinder device 25 in the hydraulic pressure device 30 shown in FIG. 3 and a control device 51 for controlling the hydraulic pressure device 30. In FIG. 4, for convenience of illustration, the tank 39 is illustrated at three locations.

  The hydraulic device 30 of the die casting machine 1 further includes an accumulator 53 that can hold the hydraulic fluid to which pressure is applied in order to supply the hydraulic fluid to the injection cylinder device 25.

  The accumulator 53 is constituted by, for example, a gas pressure type cylinder (piston type) accumulator. That is, the accumulator 53 includes a cylinder tube 53e and a piston 53f that can slide the cylinder tube 53e. The inside of the cylinder tube 53e is partitioned by a piston 53f into an air chamber 53g in which a compressed gas (for example, nitrogen) is stored and a liquid chamber 53h in which a working fluid is stored.

  The hydraulic pressure circuit 37 has a first flow path 55 that connects the pump 33 and the accumulator 53, and allows the accumulator 53 to be accumulated (filled) by the pump 33. The hydraulic circuit 37 has an ACC side direction control valve 58 in order to allow or prohibit accumulation of the accumulator 53 by the pump 33. The ACC side direction control valve 58 can allow or prohibit the flow of the hydraulic fluid in the first flow path 55.

  The hydraulic circuit 37 has a discharge flow path 56 that connects the accumulator 53 and the tank 39, and allows the hydraulic fluid to be discharged from the accumulator 53 to the tank 39. The hydraulic circuit 37 has a tank side direction control valve 59 in order to permit or prohibit the discharge of the hydraulic fluid from the accumulator 53 to the tank 39. The tank side direction control valve 59 can permit or prohibit the flow of the hydraulic fluid in the discharge flow path 56.

  As described above, the hydraulic circuit 37 connects the pump 33 and the injection cylinder device 25, and enables the pump 33 to drive the injection cylinder device 25. Specifically, the hydraulic circuit 37 includes a second flow path 61 connected to the pump 33, a third flow path 63 connected to the rod side chamber 25 a of the injection cylinder device 25, and a head side chamber of the injection cylinder device 25. And a fourth flow path 65 connected to 25b.

  For example, the second flow path 61 is branched from the first flow path 55 between the first check valve 57 and the ACC side direction control valve 58 (a part of the second flow path 61 is made common with the first flow path 55). Connected to the pump 33. The injection-side direction control valve 47C described above switches the connection state between the second flow path 61 (pump 33), the third flow path 63 (rod side chamber 25a), and the fourth flow path 65 (head side chamber 25b).

  A flow path connecting the pump 33 and a cylinder apparatus other than the injection cylinder apparatus 25, for example, a tenth flow path 93 (FIG. 3) connecting the pump 33 and the clamping cylinder apparatus 15 is also a first check. The first flow path 55 branches off between the valve 57 and the ACC side direction control valve 58.

  The hydraulic circuit 37 connects the accumulator 53 and the injection cylinder device 25, and enables the injection cylinder device 25 to be driven by the accumulator 53. Specifically, it is as follows.

  The hydraulic circuit 37 is provided in the fifth channel 67 and the fifth channel 67 that connect the accumulator 53 and the head side chamber 25b of the injection cylinder device 25, and allows or prohibits the flow from the accumulator 53 to the head side chamber 25b. Possible supply control valve 69.

  For example, the fifth flow path 67 is connected to the accumulator 53 by being connected to the first flow path 55 on the accumulator 53 side of the ACC side direction control valve 58. Note that the fifth flow path 67 may be connected to the accumulator 53 separately from the first flow path 55 (the first flow path 55 may not be partially shared).

  For example, the supply control valve 69 is closed when the pilot pressure is introduced, and allows the flow from the accumulator 53 side to the head side chamber 25b side while the pilot pressure is not introduced, while the head side chamber 25b. It is constituted by a pilot type check valve that prohibits the flow from the side to the accumulator 53 side. Accordingly, when the introduction of the pilot pressure to the supply control valve 69 is stopped, the working fluid is supplied from the accumulator 53 to the head side chamber 25b, and the injection piston 25p and the piston rod 25r move forward to the left side of the drawing.

  The hydraulic circuit 37 has a meter-out circuit for controlling the injection cylinder device 25 when hydraulic fluid is supplied from the accumulator 53 to the head side chamber 25b. Specifically, for example, the hydraulic circuit 37 includes a sixth flow path 71 that connects the rod side chamber 25a and the tank 39, and an injection-side flow rate control valve 73 that controls the flow rate of the sixth flow path 71. ing.

  The injection-side flow rate control valve 73 is configured by, for example, a servo valve that is incorporated in a servo mechanism and can modulate the flow rate steplessly in accordance with an input signal. The injection-side flow rate control valve 73 is configured to change the flow rate setting value by sequentially operating, for example, an electromagnetic control mechanism and a hydraulic control mechanism.

  By controlling the flow rate of the hydraulic fluid discharged from the rod side chamber 25a of the injection cylinder device 25 by the injection side flow rate control valve 73, the speeds of the injection piston 25p and the piston rod 25r of the injection cylinder device 25 are controlled. .

  The hydraulic circuit 37 includes a seventh flow path 75 that connects the accumulator 53 and the rear chamber 25 d of the injection cylinder device 25, and a pressure increase side flow rate control valve 77 provided in the seventh flow path 75.

  For example, the seventh flow path 75 is connected to the accumulator 53 by being connected to the first flow path 55 on the accumulator 53 side of the ACC side direction control valve 58. In addition, the 7th flow path 75 may be connected to the accumulator 53 separately from the 1st flow path 55 (the 1st flow path 55 may not be partly shared), and ACC. You may connect with respect to the 1st flow path 55 in the pump 33 side rather than the side direction control valve 58. FIG.

  The pressure-increasing side flow control valve 77 is configured by, for example, a servo valve that is incorporated in a servo mechanism and can modulate the flow rate steplessly according to an input signal. The pressure-increasing side flow rate control valve 77 is configured to change the set value of the flow rate by sequentially operating, for example, an electromagnetic control mechanism and a hydraulic control mechanism.

  By supplying the working fluid from the accumulator 53 to the rear chamber 25d through the seventh flow path 75, the pressure in the head side chamber 25b is increased through the pressure-increasing piston 25pp. At this time, the speed of pressure increase is controlled by the pressure increase side flow control valve 77.

  The hydraulic circuit 37 has an eighth flow path 79 that connects the front chamber 25 c to the tank 39 and the pump 33. For example, the eighth flow path 79 is connected to the third flow path 63, and is connected to the sixth flow path 71 on the rod side chamber 25 a side with respect to the injection-side flow rate control valve 73.

  Therefore, when the hydraulic fluid in the accumulator 53 is supplied to the rear chamber 25d and the pressure-increasing piston 25pp moves forward, the hydraulic fluid in the front chamber 25c is discharged to the tank 39 by opening the injection-side flow rate control valve 73. Further, when the injection side direction control valve 47C is switched to the position on the left side in FIG. 4 and hydraulic fluid is supplied from the pump 33 to the rod side chamber 25a and the injection piston 25p moves backward, the pump 33 also returns to the front chamber 25c. The hydraulic fluid is supplied and the pressure-increasing piston 25pp also moves backward.

  The hydraulic circuit 37 includes a ninth flow path 81 that connects the rear chamber 25 d and the tank 39, and a second check valve 82 provided in the ninth flow path 81. The ninth flow path 81 is connected to the fourth flow path 65, for example. The second check valve 82 is provided to allow a flow from the rear chamber 25d side to the injection side direction control valve 47C side, while prohibiting a flow from the injection side direction control valve 47C side to the rear chamber 25d side. It has been.

  Therefore, when the injection side direction control valve 47C is switched to the position on the left side in FIG. 3 and hydraulic fluid is supplied from the pump 33 to the front chamber 25c, and the pressure increasing piston 25pp moves backward, the hydraulic fluid in the rear chamber 25d is It is discharged to the tank 39 through the nine flow paths 81. On the other hand, when the injection side direction control valve 47C is switched to the position on the right side of FIG. 3 and hydraulic fluid is supplied from the pump 33 to the head side chamber 25b and the injection piston 25p moves forward, the second check valve 82 prevents the flow from the pump 33 to the rear chamber 25d, and the pressure-increasing piston 25pp does not move forward.

  The control device 51 includes, for example, a CPU 83 and a memory 84 such as a ROM or a RAM. The CPU 83 generates a control signal based on various electrical signals input via the input circuit 85 and outputs the generated control signal to various devices via the output circuit 86.

  The electrical signals input to the control device 51 are, for example, position sensors 87A to 87D (see FIG. 3; hereinafter, A to D) that detect the positions of the piston rods r of various cylinder devices (15, 19, 25, and 29). Detection signals S1 to S4, electrical signals P1 to P3 from the first pressure sensor 88, the second pressure sensor 89, and the third pressure sensor 90 for detecting the pressure of the hydraulic fluid, and the input device 91. It is the operation signal according to a user's operation from. The electrical signal output from the control device 51 is a control signal for controlling, for example, various valves such as the motor 35 and the directional control valve 47, and the display device 92 that presents various information to the user.

  The position sensor 87, for example, constitutes a magnetic or optical linear encoder together with a scale portion (not shown) provided on the piston rod r along the advancing and retreating direction of the piston rod r. The number of pulses corresponding to the amount of movement with respect to is output. The control device 51 can determine the position and speed of the piston rod r by counting the pulses from the position sensor 87. As a result, a member driven by the piston rod r, such as the movable die plate 12, the core, and the like. 107, the position and speed of the injection plunger 23 and the push pin 27 can be specified. Based on the detection result of the position sensor 87, the control device 51 controls the speed, output, stop position, and the like of various cylinder devices at a programmed timing.

  The first pressure sensor 88 detects the discharge pressure of the pump 33. Specifically, for example, the pressure of the hydraulic fluid between the first check valve 57 and the ACC side direction control valve 58 is detected. The second pressure sensor 89 detects the pressure of the working fluid in the accumulator 53. The third pressure sensor 90 detects the pressure of the hydraulic fluid in the head side chamber 25b. The pressure in the head side chamber 25b is approximately equal to the pressure (injection pressure) applied by the injection plunger 23 to the molten metal.

<Operation in molding cycle of die casting machine>
An operation in the molding cycle of the die casting machine 1 will be described.
(Overview of operation during the entire molding cycle)
First, an outline of the operation in the entire molding cycle will be described.

  In the die casting machine 1, first, the core 107 is disposed on the front side of the movable mold 105 by the core cylinder device 19 in the mold open state (or the initial stage of mold closing). Next, the mold clamping cylinder device 15 drives the movable die plate 12 toward the fixed die plate 11 to close the movable die 105 so that the movable die 105 contacts the fixed die 103. Clamping that increases the contact pressure of the fixed mold 103 is performed. Thereafter, the injection plunger 23 is driven by the injection cylinder device 25, and the molten metal is injected and filled into the cavity Ca. When a certain period of time has passed, in other words, when the molten metal has solidified to form a molded product, the movable die plate 12 is driven to the opposite side of the fixed die plate 11 by the clamping cylinder device 15, and the mold opening is stopped. Done. At this time, the molded product moves together with the moving mold 105 and is released from the fixed mold 103. Then, the extrusion pin 27 is driven by the extrusion cylinder device 29, and the molded product is pushed out by the extrusion pin 27 and released from the moving mold 105.

(Injection operation)
Next, the details of the injection operation in the die casting machine 1 will be described.

  FIG. 5A is a diagram showing a change over time in the injection pressure in the die casting machine 1, and FIG. 5B is a diagram showing a change over time in the injection speed (speed of the injection plunger 23) in the die casting machine 1. .

In the die casting machine 1, when the mold closing and clamping of the main mold 101 are completed and the molten metal is supplied into the sleeve 21, the injection plunger 23 starts moving forward, and low speed injection is performed. In the low speed injection, the injection plunger 23 moves forward at a relatively low speed V _L in order to prevent air from being caught by the molten metal. Incidentally, the injection pressure at which the injection plunger 23 is advanced at a speed V _L is a relatively low pressure P _L.

When the injection plunger 23 reaches a predetermined high-speed switching position (point D in FIG. 5B), the speed of the injection plunger 23 is relatively high from a relatively low speed V _L for the purpose of shortening the cycle time. The speed _VH is switched to high speed injection. The injection pressure when the injection plunger 23 moves forward at the speed V _H is a pressure P _H that is higher than the pressure P _L.

When the molten metal is substantially filled in the cavity Ca (L point in FIG. 5 (b)), since the molten metal loses escape being pressed by an injection plunger 23, the injection pressure is rapidly increased from the pressure P _H (pressure P _d ). At the same time, the injection speed is rapidly decelerated from the speed V _H (speed V _d ).

When the high-speed injection is completed, pressure increase is started (after the point M in FIG. 5B), and the injection speed is further decreased (speed V _t ) while the injection pressure is increased (pressure P _t ). Then, the injection plunger 23 stops, the injection pressure becomes the casting pressure (final pressure) _Pmax , and the filling of the molten metal is completed. Thereafter, the injection pressure is maintained at the casting pressure _Pmax .

  In order to realize the operation as described above, the control device 51 controls the motor 35 and various valves as follows.

(Open mold state)
The pump 33 is driven at a predetermined rotational speed. However, the direction control valve 47 of the various cylinder devices (15, 19, 25, and 29) is in a neutral position (closed position), and the various cylinder devices are not driven. Further, the ACC side direction control valve 58 is in the closed position, and the flow of hydraulic fluid from the pump 33 to the accumulator 53 is prohibited.

  The accumulator 53 is in an accumulated state. However, the supply control valve 69, the injection side flow rate control valve 73, and the pressure increase side flow rate control valve 77 are closed, and the injection cylinder device 25 is not driven.

(Loading the core)
The control device 51 switches the core side direction control valve 47B from the neutral position to the position on the left side in FIG. As a result, the hydraulic fluid is supplied from the pump 33 to the head side chamber 19 b of the core cylinder device 19, and the core 107 is disposed on the front surface of the moving mold 105. When the arrangement of the core 107 is completed, the control device 51 returns the core side direction control valve 47B to the neutral position.

(Closing mold and clamping)
The control device 51 switches the mold clamping side direction control valve 47A from the neutral position to the position on the left side in FIG. As a result, the hydraulic fluid is supplied from the pump 33 to the head side chamber 15b of the mold clamping cylinder device 15, the moving die plate 12 moves to the fixed die plate 11 side, and the mold closing and clamping are performed.

  When the target mold clamping force is obtained, the control device 51 controls the mold clamping side direction control valve 47A and the motor 35 so that the mold clamping force is maintained. For example, the control device 51 continues the control for setting the position of the mold clamping side direction control valve 47A on the left side in FIG. 3 and the control for driving the motor 35, that is, the mold clamping cylinder device 15 by the pump 33. Continue to supply hydraulic fluid to and maintain the clamping force. Further, for example, the control device 51 once returns the mold clamping side direction control valve 47A to the neutral position, and when necessary, the position of the mold clamping side direction control valve 47A is set as shown in FIG. In other words, the supply of hydraulic fluid to the mold clamping cylinder device 15 by the pump 33 is continued intermittently to maintain the mold clamping force at the target value. The mold clamping force is maintained until the molten metal injected into the cavity Ca is solidified later.

  The mold clamping force is detected by detecting an appropriate physical quantity such as, for example, the amount of extension of the tie bar 14, the amount of movement of the piston rod 15r of the mold clamping cylinder device 15, and the pressure of the head side chamber 15b of the mold clamping cylinder device 15. Is done. The control device 51 controls the mold clamping side direction control valve 47A and the motor 35 based on the detected mold clamping force.

(Low speed injection)
The control device 51 switches the injection side direction control valve 47C to the position on the right side of the sheet of FIG. Thus, the hydraulic fluid is supplied from the pump 33 to the head side chamber 25b, the injection piston 25p and the piston rod 25r move forward, and the injection plunger 23 moves forward.

For example, the control device 51 controls the speed of the injection plunger 23 to a predetermined low speed (V _L ) based on the detection result of the position sensor 87C (performs feedback control). The speed of the injection plunger 23 is controlled by controlling the rotational speed of the motor 35, for example. When the pump 33 is constituted by a variable displacement pump, the injection plunger 23 is controlled by controlling the discharge amount in one cycle of the pump 33 or by combining the control of the discharge amount and the rotation speed of the motor 35. The speed may be controlled.

(High speed injection)
When the position detected by the position sensor 87C reaches a predetermined high-speed switching position (point D in FIG. 5), the control device 51 performs control to switch the injection side direction control valve 47C to the neutral position, and control to open the supply control valve 69. Then, the injection side flow control valve 73 is controlled to open. As a result, the hydraulic fluid is supplied from the accumulator 53 to the head side chamber 25b, and high-speed injection is performed. The control timing of these valves is appropriately set based on a test or the like so that the transition from the low speed injection to the high speed injection is performed smoothly. The speed of the injection plunger 23 is feedback controlled so as to follow a predetermined high speed (V _H ) with a predetermined ascending curve by flow control by the injection side flow control valve 73.

  Note that the control device 51 rotates the motor 35 at the number of rotations necessary for maintaining the mold clamping force from high-speed injection to pressure increase. However, since the injection side direction control valve 47C is switched to the neutral position, the pump 33 and the injection cylinder device 25 are not directly linked to each other. .

(Deceleration)
When the injection plunger 23 reaches a predetermined deceleration start position (point L in FIG. 5), the controller 51 controls the injection-side flow rate control valve so that the injection plunger 23 decelerates with a predetermined deceleration curve at a predetermined timing. 73 is controlled.

(Pressure increase)
When the injection plunger 23 reaches a predetermined pressure increase start position (point M in FIG. 5), the control device 51 performs control to fully open the injection side flow rate control valve 73 and control to open the pressure increase side flow rate control valve 77. Do. As a result, hydraulic fluid is supplied from the accumulator 53 to the rear chamber 25d, and the hydraulic fluid in the head chamber 25b is pressurized by the pressure-increasing action of the pressure-increasing piston 25pp. Is done. The control device 51 controls the pressure increase side flow control valve 77 based on the detection value of the third pressure sensor 90 so that the injection pressure rises to a predetermined casting pressure _Pmax with a predetermined pressure increase curve.

  The supply control valve 69 is self-closed when the pressure in the head side chamber 25b is increased by the pressure increasing piston 25pp and becomes higher than the pressure in the accumulator 53. However, the pilot pressure may be introduced and closed.

(Open mold)
After a predetermined time has elapsed since the injection pressure reached the casting pressure _Pmax , in other words, after the molten metal filled in the cavity Ca has solidified, the control device 51 moves the mold clamping side direction control valve 47A to the paper surface of FIG. Switch from the left position to the right position. Thereby, the pressure release of the head side chamber 15b is performed, and further, the hydraulic fluid from the pump 33 is supplied to the rod side chamber 15a, and the mold opening is performed. When the movable die plate 12 reaches a predetermined mold opening position, the control device 51 returns the mold clamping side direction control valve 47A to the neutral position.

(Drawing out the core)
During mold opening or after mold opening, the control device 51 switches the core side direction control valve 47B from the neutral position to the position on the right side of the drawing. Thereby, the working fluid from the pump 33 is supplied to the rod side chamber 19a, and the core 107 is pulled out from the molded product. When the core 107 is pulled out from the molded product, the control device 51 returns the core-side direction control valve 47B to the neutral position.

(Extrude)
After the core 107 is pulled out, the control device 51 switches the extrusion side direction control valve 47D from the neutral position to the position on the left side of the drawing. As a result, the hydraulic fluid from the pump 33 is supplied to the head side chamber 29 a, the extrusion pin 27 is driven, and the molded product is pushed out from the moving mold 105. Thereafter, at an appropriate time until the start of the next mold closing, the control device 51 switches the extrusion side direction control valve 47D to the position on the right side of the drawing to retract the extrusion pin 27, and moves the extrusion side direction control valve 47D to the neutral position. return.

(Retraction of the injection plunger)
In other words, after the predetermined time has elapsed since the injection pressure reached the casting pressure P _max , in other words, after the molten metal filled in the cavity Ca has solidified, the control device 51 includes the injection side flow control valve 73 and the pressure increase side flow control valve. 77 is controlled to end the holding pressure. In addition, the control device 51 performs control for introducing a pilot pressure to the supply control valve 69. Thereafter, the control device 51 performs control to switch the injection side direction control valve 47C to the position on the left side of FIG. Thereby, the hydraulic fluid sent out by the pump 33 is supplied to the rod side chamber 25a and the front side chamber 25c, and the injection piston 25p (injection plunger 23) and the pressure increase piston 25pp are moved backward. When the backward movement of the injection piston 25p and the pressure increase piston 25pp is completed, the control device 51 returns the injection side direction control valve 47C to the neutral position. The retraction of the injection plunger may or may not overlap with the mold opening, the extraction of the core, and the extrusion of the molded product.

(Accumulator pressure accumulation)
When the opening of the mold, the extraction of the core, the retraction of the injection plunger, and the extrusion of the molded product are completed, and the direction control valve 47 of each cylinder device is returned to the neutral position, the control device 51 opens the ACC side direction control valve 58. Position. As a result, the hydraulic fluid is supplied from the pump 33 to the accumulator 53 to accumulate pressure in the accumulator 53. The control device 51 controls the motor 35 and the like so that the hydraulic fluid is sent to the accumulator 53 at a predetermined pressure and speed until the detection value of the second pressure sensor 89 reaches a predetermined set pressure.

<Operation in the entry and confirmation work of the die casting machine>
(Overview)
As described above, the entry operation is an operation involving entry of an operator between the die plates, and the confirmation operation is an operation for performing operation confirmation by driving each part of the die casting machine 1 after the entry operation. .

  As described above, after the entry operation is completed, it takes a relatively long time until the hydraulic device 30 is filled with the working fluid after the start of the pump is instructed and the cylinder device can be driven.

  Therefore, the control device 51 is configured to be able to selectively execute control in two modes when an instruction to start the pump is given.

  One mode is a mode in which the same control as in the prior art is executed. Hereinafter, for convenience, the mode is referred to as a “normal mode”. The normal mode is used, for example, when starting normal operation of the die casting machine 1 (starting the molding cycle) or returning to the molding cycle without performing a confirmation operation after the entry operation. However, it is also possible to perform confirmation work by control in the normal mode.

  The other mode is a mode in which control different from the conventional one is executed, and the time from the start of pump activation until the cylinder device can be driven is shorter than in the normal mode. Hereinafter, for convenience, the mode is referred to as a “special mode”. The special mode is executed in the confirmation work, for example.

  The normal mode and the special mode are switched by, for example, an operator's operation on the input device 91. Then, when activation of the pump 33 is instructed by an operator's operation on the input device 91, control of the selected mode is started.

  The control in the normal mode is also started when an instruction to switch the control mode from the special mode to the normal mode is given by the operator's operation on the input device 91 when the control in the special mode is being executed. . However, the processing procedure in this case is partly different from the processing procedure when the activation of the pump 33 is instructed in a state where the normal mode is selected in advance.

  In the drawings and the like, the special mode may be abbreviated as “S mode”. The selection of the special mode may be referred to as “S mode ON”, and the selection of the normal mode may be referred to as “S mode OFF”.

  Hereinafter, the operation in the entry work and the confirmation work will be described in detail.

(Operation during entry work)
In the approach work, first, the operator performs an operation to instruct the input device 91 to stop driving the pump 33. When an operation signal corresponding to the operation is input from the input device 91 to the control device 51, the control device 51 stops the motor 35 and stops driving the pump 33.

  Further, the control device 51 discharges the hydraulic fluid of the accumulator 53 to the tank 39, and puts the accumulator 53 in a state where the driving force is not exhibited. Specifically, the control device 51 opens the tank side direction control valve 59 and discharges the hydraulic fluid in the liquid chamber 53 h to the tank 39. The piston 53f moves toward the liquid chamber 53h until the drive limit is reached (for example, until the piston 53f contacts the end of the cylinder tube 53e or a stopper (not shown)).

  The fact that the piston 53f has reached the drive limit on the liquid chamber 53h side may be detected by a position sensor (not shown) that detects the position of the piston 53f, or after the tank side direction control valve 59 is opened, It may be estimated based on the passage of time. The estimation may be performed by the control device 51 or may be performed by an operator.

  When the driving of the pump 33 is stopped and the piston 53f of the accumulator 53 reaches the driving limit on the liquid chamber 53h side, the hydraulic device 30 of the die casting machine 1 enters a state where the driving force is not exerted. That is, the hydraulic device 30 prevents each part of the die casting machine 1 from performing an unintended operation, thereby ensuring the safety of the operator. The operation for instructing the stop of driving of the pump 33 can be regarded as an operation for setting the hydraulic device 30 in a state where the driving force is not exerted. The various directional control valves 47 are basically in a neutral position, that is, a position where hydraulic fluid is not supplied from the pump 33 to the cylinder device.

  The operator may be notified that the hydraulic device 30 is in a state where the driving force is not exerted by an appropriate output device such as a display device 92, a lamp (not shown), or a speaker (not shown). Further, an appropriate safety device may be provided so that the door 97 can be opened only when the hydraulic device 30 is in a state where the driving force is not exerted.

(Control in normal mode-When executed when the pump is stopped-)
FIG. 6A shows changes over time in the pressure of the pump line (detected pressure of the first pressure sensor 88) and the pressure of the accumulator 53 (detected pressure of the second pressure sensor 89) when the control in the normal mode is executed. FIG. The horizontal axis represents time and the vertical axis represents pressure, the solid line L _P pump pressure line, the dotted line L _A indicates the pressure of the accumulator 53.

  Before the time t0, the motor 35 and the pump 33 are stopped, and the pressure of the pump line is Pp0. Pp0 is, for example, a tank pressure. In the accumulator 53, the piston 53f is positioned at the drive limit on the liquid chamber 53h side, and the pressure is Pp2.

  At time t0, when the start of the pump 33 is instructed while the normal mode is selected, the control device 51 starts the motor 35. The activation of the motor 35 is performed by, for example, a Y-Δ activation method in which the Y connection is switched to the Δ connection.

  When the motor 35 is activated, the pump 33 rotates and the pressure in the pump line increases. However, the hydraulic fluid discharged from the pump 33 is discharged to the tank 39 through a valve (not shown) provided between the pump 33 and the ACC side direction control valve 58, and the pressure of the pump line is set to the pressure Pp1. Kept.

  When the control device 51 determines that the activation of the motor 35 is finished (time t1), the control device 51 stops discharging the hydraulic fluid from the pump 33 to the tank 39. In addition, the control device 51 performs control to open the ACC side direction control valve 58. As a result, the pressure of the pump line increases to the pressure (Pp2) of the accumulator 53, and then both the pressure of the pump line and the pressure of the accumulator 53 increase. That is, the hydraulic fluid of the pump line is supplied to the accumulator 53, and the accumulator 53 is accumulated.

  The valves other than the ACC side direction control valve 58 that control the flow of hydraulic fluid from the pump 33 or the accumulator 53 are basically closed. The condition for determining that the start of the motor 35 has ended is, for example, that the switching from the Y connection to the Δ connection has ended, or the rotation speed of the motor 35 detected by the motor sensor 43 reaches a predetermined rotation speed. It is that. The ACC side direction control valve 58 may be opened before the start of the motor 35 is completed.

  When the pressure of the accumulator 53 reaches the target filling pressure (Pp3) (time t2), the control device 51 closes the ACC side direction control valve 58 and maintains the pressure of the accumulator 53 at the target filling pressure Pp3. .

  Further, the control device 51 opens a valve (not shown) provided between the pump 33 and the ACC side direction control valve 58 to discharge the hydraulic fluid discharged from the pump 33 to the tank 39. As a result, the pressure in the pump line decreases again to the pressure Pp1.

  Thereafter, for example, when an instruction for starting a molding cycle or confirming an operation is given by an operation of the input device 91 by an operator, the control device 51 causes the pump 33 or the accumulator 53 to perform various operations according to the instruction. Drive the cylinder device. That is, the control device 51 appropriately opens and closes the valves (direction control valve 47 and supply control valve 69) that control the flow of hydraulic fluid from the pump 33 or the accumulator 53 to various cylinder devices and the like.

  Even if an instruction for starting a molding cycle or confirming the operation is given before the accumulator 53 has accumulated pressure, the control device 51 does not perform control according to the instruction until the accumulator 53 has accumulated pressure. . This instruction is not executed at all, or is executed after the accumulator 53 has completed accumulating pressure.

  That is, in the normal mode control, the various cylinder devices of the die casting machine 1 are driven by the pump 33 or the accumulator 53 on the condition that the start of the motor 35 is completed and the accumulator 53 is filled. Is possible.

(Special mode control)
FIG. 6B is a diagram corresponding to FIG. 6A when the special mode control is executed.

  The state of the die casting machine 1 before time t0 is the same as in the normal mode control. At time t0, the control when the activation of the pump 33 is instructed while the special mode is selected is the same as the control in the normal mode until time t1.

  However, the controller 51 does not start accumulating the accumulator 53 even when it determines that the start of the motor 35 is completed at the time t1. Specifically, the hydraulic fluid sent from the pump 33 is discharged to the tank 39 via a valve (not shown) between the ACC side direction control valve 58 and the motor 35. Furthermore, the ACC side direction control valve 58 may be closed at an appropriate time before time t1, and the closed state may be maintained after time t1. Therefore, the pressure of the accumulator 53 is maintained at the pressure Pp2.

  After that (after time t1), for example, when an operation confirmation instruction is given by an operator's operation on the input device 91, the control device 51 causes the pump 33 to perform various operations while the accumulator 53 is left unfilled. Drive the cylinder device.

  Specifically, the control device 51 maintains the ACC-side directional control valve 58 in a closed state from an appropriate time before the time t1 or when an instruction to drive the cylinder device is given. Further, the control device 51 stops the discharge of the hydraulic fluid from the pump 33 to the tank 39, and switches the directional control valve 47 corresponding to the cylinder device instructed to drive from the neutral position (stop position) to another position. Then, the hydraulic fluid is supplied from the pump 33 to the cylinder device. In the operation check, the driving direction, the driving amount, and the speed of the cylinder device are appropriately set by, for example, an operation on the input device 91.

  Even if an instruction for confirming the operation is given before it is determined that the activation of the motor 35 is completed, the control device 51 performs control according to the instruction until it is determined that the activation of the motor 35 is completed. Not performed. The instruction is not executed at all, or is executed after it is determined that the activation of the motor 35 is finished.

  That is, in the special mode control, the various cylinder devices of the die casting machine 1 are in a state where they can be driven by the pump 33 on condition that the start of the motor 35 is completed.

(Normal mode control-When switching from special mode control)
FIG. 6C is a diagram corresponding to FIGS. 6A and 6B when the control mode is switched from the special mode to the normal mode when the control in the special mode is executed. .

  From time t0 to time t3, as in FIG. 6B, a state in which the special mode control is executed is shown. That is, the motor is started up by time t1, and after time t1, driving of various cylinder devices by the pump 33 is allowed.

  When switching from the special mode to the normal mode is instructed at time t3, the control device 51 operates in the same manner as after time t1 in FIG. That is, the control device 51 stops discharging the hydraulic fluid from the pump 33 to the tank 39, opens the ACC side direction control valve 58, and accumulates the accumulator 53 to the pressure Pp3. In addition, the control device 51 prohibits driving of various cylinder devices from time t3 to time t4 (corresponding to time t2 in FIG. 6A), and after time t4, by the pump 33 or the accumulator 53. Allow drive of various cylinder devices.

  FIG. 7 is a flowchart illustrating an example of a procedure of processing executed by the control device 51 in order to realize the operations in the above-described entry work and confirmation work. This process is started when the die casting machine 1 is powered on, for example.

  In step ST1, the control device 51 determines whether or not an operation for instructing the input device 91 to start the pump 33 has been performed, and waits until it is determined that the operation has been performed. If the control device 51 determines that the operation has been performed, the control device 51 proceeds to step ST2.

  In step ST2, the control device 51 determines whether or not the special mode is selected. If it is determined that the special mode is not selected (the normal mode is selected), the control device 51 activates the motor 35 (step ST4) and accumulates the accumulator 53 (step ST4) as described above. ), Driving of various cylinder devices is permitted (step ST5).

  On the other hand, if it is determined in step ST2 that the special mode is selected, the control device 51 only starts the motor 35 (step ST6) as described above, in other words, accumulates the pressure in the accumulator 53. Instead, the driving of various cylinder devices is permitted (step ST5). After the drive permission (step ST5), various cylinder devices are driven according to the operator's operation on the input device 91 according to another control flow (not shown).

  In step ST7, the control device 51 determines whether or not the control mode has been switched from the special mode to the normal mode by the operator's operation on the input device 91. If it is determined in step ST2 that the normal mode is selected, and if it is determined that the normal mode has been switched when step ST7 is executed previously, the determination result in step ST7 Is No.

  If it is determined in step ST7 that the control mode has been switched from the special mode to the normal mode, the control device 51 returns to step ST4. That is, the process in the case where it is determined in step ST2 that the normal mode is selected is executed from the middle (omitting step ST3).

  On the other hand, when it is determined in step ST7 that the switching from the special mode to the normal mode is not performed (when the normal mode or the special mode is maintained), the control device 51 controls the operator input device 91. It is determined whether or not an instruction to stop the pump 33 is given by the operation (step ST9).

  If it is determined that the stop of the pump 33 is not instructed, the control device 51 returns to step ST7. On the other hand, when it is determined that the stop of the pump 33 is instructed, the control device 51 stops the motor 35 and releases the working fluid of the accumulator 53 to the tank 39 via the tank side direction control valve 59. Then, the control device 51 returns to step ST1.

  According to the above embodiment, the die casting machine 1 includes the accumulator 53, the pump 33 capable of accumulating the accumulator 53, and one or more cylinder devices (15, 19,...) Driven by hydraulic fluid from the accumulator 53 or the pump 33. 25, 29). The die casting machine 1 also includes a hydraulic circuit 37 that controls the flow of hydraulic fluid between the accumulator 53, the pump 33, and one or more cylinder devices, and a controller 51 that controls the pump 33 and the hydraulic circuit 37. . The control device 51 can selectively execute normal mode control and special mode control when the accumulator 53 is in an unfilled state and the pump 33 is in a stopped state. In the normal mode control, the control device 51 fills the accumulator 53 with the pump 33 (step ST4), and then can drive at least one of the one or more cylinder devices with the accumulator 53 or the pump 33. In the special mode control, the control device 51 can drive at least one of one or more cylinder devices by the pump 33 while blocking the flow from the pump 33 to the accumulator 53 and leaving the accumulator 53 unfilled. It is.

  Therefore, the die casting machine 1 can drive the cylinder device without accumulating the accumulator 53 by selecting the special mode when performing the confirmation work after the entry work. As a result, the time from the start of pump activation until the cylinder device can be driven is shortened by the time required for accumulator 53 to accumulate pressure (time T2 in FIG. 6A). And when approach work and confirmation work are performed repeatedly, work time is shortened drastically. As an example, the time T1 in FIG. 6 is 4 seconds and the time T2 is 24 seconds. Depending on the configuration of the accumulator, the time T2 may be about 40 seconds.

  The die casting machine 1 further includes a rotary motor 35 that drives the pump 33, and the control device 51 can switch the control to be executed to the control in the normal mode while the control in the special mode is being executed. When the accumulator 53 is in an unfilled state and the pump 33 is in a stopped state, the control device 51 activates the motor 35 when starting control in the normal mode or special mode (steps ST3 and ST6). Thus, driving of the pump 33 is started. When switching the control to be performed to the normal mode control during the execution of the special mode control, the control device 51 starts the normal mode control while maintaining the rotation of the motor 35, and fills the accumulator 53 (step). ST4).

  Therefore, when the molding cycle is started after the confirmation work, the time required for starting the motor (T1 in FIG. 6) is unnecessary, and the molding cycle can be started quickly.

  In the above embodiment, the normal mode is an example of the first mode of the present invention, the special mode is an example of the second mode of the present invention, and the ACC side directional control valve 58 is the first mode of the present invention. The supply control valve 69 is an example of the second valve of the present invention, and the injection side direction control valve 47C is an example of the third valve of the present invention.

  The present invention is not limited to the above embodiment, and may be implemented in various aspects.

  The molding machine is not limited to a die casting machine. For example, an injection molding machine that molds a resin may be used. The molding machine is not limited to a cold chamber machine, and may be a hot chamber machine. Further, the molding machine is not limited to a horizontal mold clamping horizontal injection type, and may be a horizontal mold clamping type or a vertical injection type. The mold clamping method is not limited to the toggle method, and may be, for example, a direct pressure type that directly transmits the driving force of the hydraulic cylinder device to the die plate. The molding machine is not limited to an apparatus in which mold clamping, injection, and the like are generally driven by a hydraulic device. For example, a hybrid machine in which mold clamping is performed by a motor (electric motor) may be used.

  The accumulator is not limited to a cylinder type. The accumulator may be a gravity type that applies a load of weight to the hydraulic fluid, a spring type that applies a restoring force of a spring to the hydraulic fluid, or a gas and hydraulic fluid. It may be of a diaphragm type that is isolated by a flexible diaphragm. The accumulator may be connected to a gas accumulator.

  The accumulator is not limited to that for the injection cylinder, and may be for a clamping cylinder, for example. The accumulator for the injection cylinder may also be used for mold clamping. An injection accumulator and a pressure increasing accumulator may be provided separately. In the embodiment, the low speed injection is performed by the hydraulic fluid discharged from the pump. However, the low speed injection may be performed by the hydraulic fluid discharged from the accumulator.

  The pump may be stopped when the hydraulic fluid does not need to be supplied to the cylinder device or the accumulator, and may be driven as necessary. Even in this case, there is an effect of shortening the time by omitting filling of the accumulator in the second mode control. The drive source for driving the pump is not limited to the motor, and may be, for example, an internal combustion engine.

  The flow path and valve of the hydraulic circuit may be appropriately configured. 3 and 4 are merely examples of the hydraulic circuit. For example, the first to third valves can be replaced with any known valve that can open and close the flow path.

DESCRIPTION OF SYMBOLS 1 ... Die casting machine (molding machine), 53 ... Accumulator, 33 ... Pump, 25 ... Injection cylinder apparatus, 37 ... Hydraulic circuit, 51 ... Control apparatus.

Claims (5)

An accumulator,
A pump capable of filling the accumulator;
One or more cylinder devices driven by hydraulic fluid from the accumulator or the pump;
A hydraulic circuit for controlling the flow of hydraulic fluid between the accumulator, the pump and the one or more cylinder devices;
A control device for controlling the pump and the hydraulic circuit;
Have
The control device includes:
When the accumulator is in an unfilled state and the pump is in a stopped state, the first mode control and the second mode control can be selectively executed.
In the control of the first mode, the accumulator is filled by the pump, and then at least one of the one or more cylinder devices can be driven by the accumulator or the pump.
In the control in the second mode, it is possible to drive at least one of the one or more cylinder devices by the pump while blocking the flow from the pump to the accumulator and leaving the accumulator in an unfilled state. Molding machine. A rotary electric motor for driving the pump;
The control device includes:
During the execution of the second mode control, the control to be executed can be switched to the first mode control,
When the control of the first mode or the second mode is started when the accumulator is unfilled and the pump is stopped, the pump is driven by starting the electric motor. Start,
When the control to be executed is switched to the control in the first mode during the execution of the control in the second mode, the control in the first mode is started while maintaining the rotation of the electric motor, and the accumulator is charged by the pump. The molding machine according to claim 1. The one or more cylinder devices include an injection cylinder device that drives the injection plunger to inject the molding material into the cavity when the hydraulic fluid is supplied from the accumulator,
The control device includes:
In the control of the first mode, the injection cylinder device can be driven by the accumulator,
The molding machine according to claim 1 or 2, wherein, in the control in the second mode, the injection cylinder device can be driven by the pump. The hydraulic circuit is
A first valve capable of allowing or prohibiting the flow of hydraulic fluid from the pump to the accumulator;
A second valve capable of allowing or prohibiting the flow of hydraulic fluid from the accumulator to at least one of the one or more cylinder devices;
One or more third valves capable of allowing or prohibiting the flow of hydraulic fluid from the pump to the one or more cylinder devices;
The molding machine according to any one of claims 1 to 3. An accumulator, a pump capable of filling the accumulator, one or more cylinder devices driven by the accumulator or hydraulic fluid from the pump, and a working fluid between the accumulator, the pump and the one or more cylinder devices. A control device for controlling the pump and the hydraulic circuit, provided in a molding machine having a hydraulic circuit for controlling a flow;
When the accumulator is in an unfilled state and the pump is in a stopped state, the first mode control and the second mode control can be selectively executed.
In the control of the first mode, the accumulator is filled by the pump, and then at least one of the one or more cylinder devices can be driven by the accumulator or the pump.
In the control in the second mode, it is possible to drive at least one of the one or more cylinder devices by the pump while blocking the flow from the pump to the accumulator and leaving the accumulator in an unfilled state. Control device for molding machine.

Images