JP2020199527A - Molding machine and hydraulic circuit control method - Google Patents

Abstract

To provide a molding machine which can finely control a position of a rod of a hydraulic cylinder, and further, can finely control a pressing force when molding a work-piece.SOLUTION: With respect to a hydraulic cylinder mechanism of a molding machine, a motion controller selects mutually different modes from a position control mode (position) for controlling a head (pushing) side motor or a rod (pulling) side motor so that an actual rod position becomes a target rod position, a pressure control mode (pressure) for controlling the head (pushing) side motor or the rod (pulling) side motor so that an actual hydraulic pressure of a hydraulic cylinder becomes a target hydraulic pressure, and a counter pressure mode (counter pressure) for operating the head (pushing) side motor or the rod (pulling) side motor, and supplying a counter hydraulic pressure to a corresponding head (pushing) side hydraulic pressure chamber or a rod (pulling) side hydraulic pressure chamber, and simultaneously controls the head (pushing) side motor and the rod (pulling) side motor respectively.SELECTED DRAWING: Figure 5

Description

The present invention relates to a molding machine including a hydraulic cylinder mechanism, in which a piston of the hydraulic cylinder mechanism is moved forward and backward to form a workpiece.

As a conventional molding machine, for example, the press molding machines described in Patent Document 1 and Patent Document 2 are known. The press molding machine described in Patent Document 1 drives one pressing cylinder, a slide provided at the tip of a piston rod extending downward from the pressing cylinder, one pump for supplying flood control to the pressing cylinder, and the pump. It is equipped with a motor. Then, the pump is driven by one motor, the piston rod is advanced from the pressing cylinder, the slide is pushed down toward the work, and the work is press-formed. Further, the press molding machine described in Patent Document 1 includes two reaction force cylinders provided in a system different from the above-mentioned hydraulic circuit and capable of supporting the slide from below, and an accumulator connected to these reaction force cylinders. When the press molding is completed, pressure is supplied from the accumulator to the reaction cylinder to move the slide upward toward the pressing cylinder and return it to the original upper limit position. As a result, the cycle in which the slide reciprocates once between the upper limit position and the lower limit position is completed.

In the press molding machine described in Patent Document 2, the piston is slidably arranged in the internal space of the hydraulic cylinder, and the end of the piston rod is coupled to the piston. The internal space of the hydraulic cylinder is divided into a rod-side oil chamber in which the piston rod is penetrated and arranged with the piston as a boundary and a head-side oil chamber on the opposite side of the piston rod. The rod-side oil chamber and the head-side oil chamber are connected to the two discharge ports of the bidirectional pump, respectively. The bidirectional pump has an oil tank and is driven by a servomotor. When the servomotor rotates in the forward direction, the bidirectional pump supplies flood control to the oil chamber on the head side from one discharge port and pushes down the piston to press-mold the workpiece. After that, the servomotor rotates in the reverse direction, and the bidirectional pump supplies oil to the oil chamber on the rod side from the other discharge port, pulls up the piston, and returns it to the original position. As a result, the cycle of reciprocating the original position where the piston is retracted and the press forming position where the piston is advanced is completed.

Japanese Unexamined Patent Publication No. 2000-329104 Japanese Unexamined Patent Publication No. 2000-312929

In recent years, it has been required to meet the demand for larger workpieces and faster press forming cycles. Further, in order to improve the press molding technique, it is required to apply a desired press pressure to a plastic or the like containing fibers.

In a hydraulic circuit that supplies oil pressure to a pressing cylinder with one pump and one motor as in Patent Document 1 and Patent Document 2, it is difficult to precisely control the operation of the slide such as fine adjustment of the slide position. In addition, it is difficult to finely control the press pressure of the slide according to the properties of the work.

In particular, since the bidirectional pump as in Patent Document 2 is a special pump, it is difficult to increase the pump capacity or it is very expensive.

In view of the above circumstances, the present invention can finely control the position of the piston of the hydraulic cylinder in a wide speed range from high-speed movement to low-speed movement, and finely control the pushing force of the piston when forming the workpiece. Furthermore, it is an object of the present invention to provide a technique capable of realizing a hydraulic circuit with a general-purpose pump in which the suction port and the discharge port do not alternate.

For this purpose, the molding machine according to the present invention has at least one push side hydraulic chamber and one pull side hydraulic chamber partitioned by a hydraulic cylinder and a piston, and a liquid that displaces a slider for molding in conjunction with the piston. A push-side hydraulic circuit that has a pressure cylinder mechanism, a push-side pump and a push-side motor that is drive-coupled to the push-side pump, and supplies hydraulic fluid to the push-side hydraulic chamber, and a pull-side pump that is drive-coupled to the pull-side pump and this pull-side pump. A motion that controls the pull-side hydraulic circuit that has a motor and supplies the hydraulic fluid to the pull-side hydraulic chamber, and the push-side hydraulic circuit and the pull-side hydraulic circuit in one mode selected from a plurality of modes. It is equipped with a controller. The plurality of modes are a position control mode in which the push side motor or the pull side motor is controlled so that the actual position of the slider becomes the target slider position, and a position control mode in which the actual hydraulic pressure in the push side hydraulic chamber becomes the target hydraulic pressure or the pull side. A pressure control mode that controls the push-side motor or pull-side motor so that the actual hydraulic pressure in the hydraulic chamber reaches the target hydraulic pressure, the total pushing force applied to the piston by one or more push-side hydraulic chambers, and 1 or Of the total attractive force applied to the piston by the plurality of pull-side hydraulic chambers, the push-side motor or pull-side motor corresponding to one is operated so that one is smaller than the other, and the push-side hydraulic chamber corresponding to one is operated. Alternatively, the push-side hydraulic circuit and the pull-side hydraulic circuit are simultaneously controlled in different modes among a plurality of modes, including a counter pressure mode for supplying the counter hydraulic pressure to the pull-side hydraulic chamber.

According to the present invention, since one rod is controlled by two motors from the head side and the rod side, the position of the rod of the hydraulic cylinder mechanism can be set in a wide speed range from high speed movement to low speed movement of the rod. It can be finely controlled, and the pushing force can be finely controlled when the workpiece is formed by a press or the like. Furthermore, since a general-purpose pump can be used for the push-side and pull-side pumps instead of the bidirectional pump, it is possible to increase the size of the molding machine at low cost. Further, the power consumption can be reduced by downsizing the push-side and pull-side motors and the regenerative operation, and the energy saving of the molding machine can be achieved. The hydraulic cylinder mechanism of the present invention may have one hydraulic cylinder, or may have a plurality of hydraulic cylinders. The hydraulic cylinder may be a single-acting type having one hydraulic chamber, or a double-acting type having two hydraulic chambers. The plurality of hydraulic cylinders may be operated by a common push-side or pull-side hydraulic circuit, or may be operated by a pair of push-side and pull-side hydraulic circuits provided for each hydraulic cylinder. As a simple aspect, the present invention comprises one double-acting hydraulic cylinder and a pair of push-side and pull-side hydraulic circuits.

When a plurality of hydraulic cylinders are provided, one motion controller can control a number of motors that are integral multiples of the number of hydraulic cylinders. As a result, a large slide that presses the work can be controlled in parallel. The push side hydraulic circuit and the pull side hydraulic circuit are provided separately. One or more push-side hydraulic circuits are provided, and the same applies to pull-side hydraulic circuits. The control of each hydraulic circuit of the present invention is executed by the (rotational) speed control or torque control of each motor. Specifically, for example, the above-mentioned position control mode is executed by controlling the (rotational) speed of each motor, the above-mentioned counter pressure mode is executed by controlling each motor by torque, and the above-mentioned pressure control mode is each. It is executed by controlling the (rotational) speed of the motor. Theoretically, each of the above-mentioned three modes can be executed only by the (rotational) speed control of each motor, or can be executed only by the torque control of each motor. The push-side hydraulic pressure may be detected by a push-side hydraulic pressure sensor connected to the push-side hydraulic pressure chamber. The pull-side hydraulic pressure may also be detected by a pull-side hydraulic pressure sensor connected to the pull-side hydraulic pressure chamber. The rod position may be detected by a position sensor provided on the rod. The motor torque may be calculated by, for example, the motion controller based on the current value of the motor.

The force applied to the slider or the like by the hydraulic circuit in the counter pressure mode may be smaller than the force applied in the opposite direction by the other hydraulic circuit. As a result, the counter hydraulic pressure circuit is suitably controlled by applying the counter hydraulic pressure from the hydraulic pressure circuit that is set to the counter pressure mode. If the actual hydraulic pressure of the hydraulic circuit in the counter pressure mode is approximately 0 and the actual hydraulic pressure of the other hydraulic circuit is much larger than 0, the hydraulic pressure difference between the two hydraulic circuits is too large. , The other side hydraulic circuit becomes difficult to control. As one aspect of the present invention, the pull-side hydraulic chamber and the push-side hydraulic chamber are located at both ends of the hydraulic cylinder 1 on the rod side through which the rod penetrates and on the side opposite to the rod when viewed from the piston. Occupy each end on the head side where it is located. Therefore, the pull-side hydraulic chamber is also called a rod-side hydraulic chamber, and the push-side hydraulic chamber is also called a head-side hydraulic chamber. According to this aspect, the push side and the pull side hydraulic chambers are provided on the head side and the rod side of the common hydraulic cylinder, respectively.

As one aspect of the present invention, when the motion controller advances the rod from the hydraulic cylinder, the push side (head side) hydraulic pressure circuit is controlled in the position control mode, and at the same time, the pull side (rod side) hydraulic pressure circuit is counter-pressured. Control in mode or pressure control mode. According to this aspect, the rod can be moved at high speed, and the forming cycle is shortened. Further, by controlling the rod-side hydraulic circuit in the pressure control mode, the next time the work is pressurized, it is possible to quickly shift to the next mode.

As another aspect of the present invention, when the rod is retracted to the hydraulic cylinder, the motion controller controls the pull side (rod side) hydraulic circuit in the position control mode, and at the same time, counters the push side (head side) hydraulic circuit. Control in pressure mode or pressure control mode. According to this aspect, the rod can be retracted at high speed, and the forming cycle is shortened.

A mold is attached to the slider, and a work is placed near the slider, and the slider presses the mold against the work. Since the slider is pushed by the rod to approach the work and is pulled by the rod to move away from the work, the pulling direction means the direction away from the work, and the pushing direction means the direction approaching the work. As another aspect of the present invention, the plurality of hydraulic cylinders are arranged on the pulling direction side when viewed from the slider, and the pushing side hydraulic chamber is located on the opposite side of the end of one hydraulic cylinder from the rod when viewed from the piston. It occupies the end on the head side, and the pull-side hydraulic chamber occupies the end on the rod side through which the rod penetrates among the ends of other hydraulic cylinders. According to this aspect, the push side and pull side hydraulic chambers are provided at both ends of a common hydraulic cylinder. According to this aspect, the pushing side hydraulic chamber is provided on the head side of the hydraulic cylinder of 1, and the pulling side hydraulic chamber is provided on the rod side of the other hydraulic cylinder.

As yet another aspect of the present invention, the plurality of hydraulic cylinders are arranged on the pushing direction side and the pulling direction side as viewed from the slider, and the pushing side hydraulic chamber is the end portion of the hydraulic cylinder arranged on the pulling direction side. Of these, the end on the head side, which is located on the side opposite to the rod when viewed from the piston, is occupied, and the pull-side hydraulic chamber is the end of the hydraulic cylinder arranged on the pushing direction side, which is the rod when viewed from the piston. Occupies the end on the head side located on the opposite side. According to this aspect, the push-side hydraulic chamber is provided on the head side of one hydraulic cylinder, and the pull-side hydraulic chamber is provided on the head side of the other hydraulic cylinder.

In the control method of the present invention, a push-side hydraulic circuit that supplies the hydraulic pressure in the pushing direction to the hydraulic cylinder and a pull-side hydraulic circuit that supplies the hydraulic pressure in the pulling direction to the hydraulic cylinder are selected from a plurality of modes. This is a method of controlling in one mode, and these multiple modes are positions in which the push-side hydraulic circuit or the pull-side hydraulic circuit is controlled so that the actual position of the piston sliding in the hydraulic cylinder becomes the target position. Control mode and push-side hydraulic circuit or pull-side hydraulic circuit so that the actual hydraulic pressure in the pushing direction becomes the target hydraulic pressure, or the actual hydraulic pressure in the pulling direction becomes the target hydraulic pressure. The pressing side corresponding to one of the pressure control mode to be controlled, the total pushing force obtained by the hydraulic pressure in the pushing direction, and the total pulling force obtained by the hydraulic pressure in the pulling direction so that one is smaller than the other. The hydraulic circuit or the pull-side hydraulic circuit includes a counter pressure mode for generating a counter hydraulic pressure, and the push-side hydraulic circuit and the pull-side hydraulic circuit are simultaneously controlled in different modes among a plurality of modes. According to such a control method, the same operation and effect as the above-mentioned molding machine of the present invention can be obtained.

As described above, according to the present invention, the position of the rod of the hydraulic cylinder can be finely controlled by two or more pumps, and precise control is possible in a wide speed range from high speed to low speed. Further, in the molding machine for pressing, the pressing pressure can be finely controlled. Further, a general-purpose pump can be used for each pump, so that the molding cycle can be increased and the molding machine can be increased in size. In the present invention, since it is possible to operate a plurality of hydraulic cylinder mechanisms in the same manner with one motion controller, it is possible to provide hydraulic cylinder mechanisms at each corner of the slide and perform parallel control so that the slide does not tilt. it can.

It is an overall view which shows typically the molding machine which becomes one Embodiment of this invention. It is a block diagram which shows the position control mode which this embodiment executes. It is a block diagram which shows the counter pressure mode which this embodiment executes. It is a block diagram which shows the pressure control mode which this embodiment executes. It is a figure which shows the molding cycle which this embodiment performs. It is an overall view which shows typically the molding machine which becomes the other embodiment of this invention. It is an overall view which shows typically the molding machine which becomes still another Embodiment of this invention. It is an overall view which shows typically the molding machine which becomes the modification of the embodiment shown in FIG.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is an overall view schematically showing a press molding machine as a molding machine according to an embodiment of the present invention.

The press molding machine 10 of the present embodiment includes a hydraulic cylinder mechanism 11, a hydraulic circuit 21 that supplies hydraulic pressure to the hydraulic cylinder mechanism 11, and a motion controller MC that controls the hydraulic circuit 21.

The hydraulic cylinder mechanism 11 is a double-acting hydraulic cylinder having a hydraulic cylinder 12, a piston 13, and a piston rod (hereinafter, simply referred to as a rod 14). The end of the rod 14 is connected to the piston 13 inside the hydraulic cylinder 12. The rod 14 penetrates one end of the hydraulic cylinder 12 and extends to the outside of the hydraulic cylinder 12. A slide 15 as a pressing body is connected to the tip of the rod 14. The slide 15 is provided with a position sensor 18 that detects the position of the slide 15.

The hydraulic cylinder 12 and the rod 14 extend in the vertical direction, and the tip of the rod 14 is at the lower end. When the piston 13 arranged inside the hydraulic cylinder 12 slides in the vertical direction, the rod 14 moves forward so as to be pushed out from the hydraulic cylinder 12, or retracts so as to be pulled into the hydraulic cylinder 12. To do. The internal space of the hydraulic cylinder 12 is partitioned into a head-side hydraulic chamber 12h and a rod-side hydraulic chamber 12r with the piston 13 as a partition wall.

The slide 15 is connected to the tip of the rod 14 on the upper surface, and the upper die 16 is attached to the lower surface. The lower mold 17 is arranged below the upper mold 16. The upper mold 16 and the lower mold 17 form a pair of molds. Work W is placed on the lower mold 17. The work W is not particularly limited to a forged product made of a metal material, a carbon fiber reinforced plastic (CFRP), or the like.

The hydraulic circuit 21 has two systems, a head-side hydraulic circuit 22 and a rod-side hydraulic circuit 32, both of which are separated. As shown in FIG. 1, a system connected to the head side hydraulic chamber 12h with the piston 13 as a boundary is referred to as a head side head, and a system connected to the rod side hydraulic chamber 12r is referred to as a rod side rod.

The head-side hydraulic circuit 22 has a head-side passage 23 having one end connected to the head-side hydraulic chamber 12h and the other end connected to the hydraulic fluid tank 24b, and a head-side pump Ph provided in the middle of the head-side passage 23. A hydraulic pressure sensor 25 and a relief valve 26 connected to the head-side passage 23, a servomotor SMh that is drive-coupled to the head-side pump Ph, and a hydraulic fluid tank 24c that receives the hydraulic fluid flowing out of the relief valve 26 are included.

The head-side hydraulic circuit 22 supplies hydraulic pressure to the head-side hydraulic chamber 12h to advance the rod 14 to push down the slide 15, or when the slide 15 is pulled up, the hydraulic pressure in the head-side hydraulic chamber 12h. Do not come off suddenly. The head-side hydraulic circuit 22 of the present embodiment is also referred to as a push-side hydraulic circuit, the head-side hydraulic chamber 12h is also referred to as a push-side hydraulic chamber, the head-side pump Ph is also referred to as a push-side pump, and the servomotor SMh is a push-side motor or head. Also called a side motor.

The rod-side hydraulic circuit 32 is also configured in the same manner as described above, with one end connected to the rod-side hydraulic chamber 12r and the other end connected to the hydraulic fluid tank 34b in the middle of the rod-side passage 33 and the rod-side passage 33. The rod-side pump Pr provided, the hydraulic pressure sensor 35 and the relief valve 36 connected to the rod-side passage 33, the servomotor SMr that is drive-coupled to the rod-side pump Pr, and the operation of receiving the hydraulic fluid flowing out from the relief valve 36. Includes liquid tank 34c.

The rod-side hydraulic circuit 32 supplies hydraulic pressure to the rod-side hydraulic chamber 12r to retract the rod 14 and pull up the slide 15 or push down the slide 15 to push down the rod-side hydraulic chamber 12r. Do not come off suddenly. The rod-side hydraulic circuit 32 of the present embodiment is also referred to as a pull-side hydraulic circuit, the rod-side hydraulic chamber 12r is also referred to as a pull-side hydraulic chamber, the rod-side pump Pr is also referred to as a pull-side pump, and the servomotor SMr is a pull. Also called a side motor or a rod side motor.

The motion controller MC is an upper control unit that controls a plurality of systems at the same time, and controls the lower servomotors SMh and SMr, respectively, to control each system of the hydraulic circuit 21 (head side hydraulic circuit 22 and rod side). The hydraulic circuit 32) is operated individually. Therefore, the motion controller MC selects the optimum one mode from the plurality of modes on the condition of the position, speed, and press pressure of the slide 13, and the hydraulic pressure circuits 22 and 32 (specifically) according to the mode. Specifically, each servomotor SMh, SMr) is controlled. The configurations of the hydraulic circuits 22 and 32 may be the same.

Next, a plurality of modes executed by this embodiment will be described with reference to FIGS. 2 to 4.

The motion controller MC includes a target command means 42 for setting a target related to the slide 15 or the rod 14, and a control calculation unit 43 for calculating a command corresponding to the target. Each of the servomotors SMh and SMr has a rotation speed sensor Uv that detects the rotation speed of the motor rotation shaft, and is connected to a servo amplifier A provided in each of the servomotors SMh and SMr. When the servo motor SMh and the servo motor SMr are not particularly distinguished in the following description, they are simply referred to as the servo motor SM. Further, when the head side pump Ph and the rod side pump Pr are not particularly distinguished, they are simply referred to as pump P.

The target command means 42 selects one mode from a plurality of modes based on a program stored in advance, and outputs a control command corresponding to the selected mode to the servo amplifier of the head-side servomotor SMh. , The target value corresponding to the selected mode is output to the control calculation unit 43. Further, the target command means 42 also controls the rod-side servomotor SMr in the same manner. One motion controller MC individually controls a plurality of servomotors SM at the same time.

FIG. 2 is a configuration diagram showing a position control mode among a plurality of modes. When the target command means 42 selects the position control mode, the servo amplifier A of the servomotor SM outputs a rotation speed control command to execute the rotation speed control of the servomotor SM. Then, the target command means 42 outputs the target position St (for example, the target position of the slide 15) to the control calculation unit 43.

The control calculation unit 43 calculates the target rotation speed Vt based on the target position St and the actual position Sd of the slide 15 input from the position sensor 18, and outputs the target rotation speed Vt to the servo amplifier A.

The servo amplifier A outputs a control command SMcmd to the servomotor SM based on the target rotation speed Vt and the actual rotation speed Vd obtained from the rotation speed sensor Uv, and feedback-controls the servomotor SM. While the pump P of the hydraulic circuit 21 is rotated by the servomotor SM, the hydraulic circuit 21 is operated to supply hydraulic pressure from the hydraulic circuit 21 to the hydraulic cylinder mechanism 11. The hydraulic cylinder mechanism 11 pushes down or pulls up the slide 15.

The motion controller MC controls a plurality of servomotors SM at the same time. Therefore, the target command means 42 also outputs a torque or rotation speed control command to the servo amplifiers of other systems. The control calculation unit 43 also outputs the target torque or the target rotation speed to the servo amplifiers of other systems.

FIG. 3 is a configuration diagram showing a counter pressure mode executed by the present embodiment. When the target command means 42 selects the counter pressure mode, a torque control command is output to the servo amplifier A of the servomotor SM to execute torque control of the servomotor SM. Then, the target command means 42 outputs the target torque Tt of the servomotor SM to the control calculation unit 43. The control calculation unit 43 outputs the target torque Tt to the servo amplifier A.

The servo amplifier A outputs a control command SMcmd to the servomotor SM based on the target torque Tt and the actual torque Td calculated from the current value flowing through the servomotor SM, and feedback-controls the servomotor SM. While the pump P of the hydraulic circuit 21 is rotated by the servomotor SM, the hydraulic circuit 21 is operated, and the hydraulic pressure in the head side hydraulic chamber 12h or the rod side hydraulic chamber 12r is maintained higher than the atmospheric pressure. However, the hydraulic pressure in the counter pressure mode is weaker than that in the pressure control mode described below. The counter pressure mode is executed in order to suppress a sudden volume reduction of the head side hydraulic chamber 12h or the rod side hydraulic chamber 12r.

The counter pressure mode is not limited to the feedback control described above. As a modification (not shown), the servomotor SM may be open-loop controlled, or may be a simple operation in which the actual torque is not monitored at all without executing the control for setting the target value. This is because it is sufficient for the servomotor SM to apply the counter hydraulic pressure to the other side hydraulic pressure circuit so that the actual hydraulic pressure of its own hydraulic pressure circuit is equal to or lower than the actual hydraulic pressure of the other side hydraulic pressure circuit in the counter pressure mode. is there.

The counterpart hydraulic pressure circuit to which the counter hydraulic pressure is applied is suitably controlled while balancing the counter hydraulic pressure. Conventionally, the counter hydraulic pressure is applied by a relief valve. However, since the relief valve has a structure that dissipates the energy of pressure, there is room for improvement in terms of energy efficiency. According to the present embodiment, by operating the hydraulic circuit on the side where the hydraulic fluid flows out from the hydraulic pressure chamber in the counter pressure mode, the pressure previously discarded can be taken out as regenerative energy, and the energy efficiency is improved. .. If the counter hydraulic pressure is not applied to the hydraulic chamber to which the hydraulic fluid is sent from the opposite side (the hydraulic chamber on the side that flows out from the hydraulic chamber), the hydraulic pressure circuit to which the hydraulic fluid is sent becomes difficult to control. Become. For example, if the pressure in the rod-side hydraulic chamber is approximately 0 when the head-side hydraulic circuit sends the hydraulic fluid to the head-side hydraulic chamber, the head-side hydraulic chamber loses balance and the slider is moved to the target position. It becomes difficult to displace or apply the desired pushing force to the slider.

FIG. 4 is a configuration diagram showing a pressure control mode executed by this embodiment. When the target command means 42 selects the pressure control mode, the servo amplifier A of the servomotor SM outputs a rotation speed control command to execute the rotation speed control of the servomotor SM. Then, the target command means 42 outputs the target hydraulic pressure Pt to the control calculation unit 43.

The control calculation unit 43 has a target rotation speed Vt based on the target hydraulic pressure Pt and the actual hydraulic pressure Pd of the head side hydraulic pressure chamber 12h or the rod side hydraulic pressure chamber 12r input from the hydraulic pressure sensor 25 or the hydraulic pressure sensor 35. Is calculated and output to the servo amplifier A.

The servo amplifier A outputs a control command SMcmd to the servomotor SM based on the actual rotation speed Vd obtained from the rotation speed sensor Uv, and feedback-controls the servomotor SM. While the pump P of the hydraulic circuit 21 is rotated by the servomotor SM, the hydraulic circuit 21 is driven, and the hydraulic pressure of the head side hydraulic chamber 12h or the rod side hydraulic chamber 12r is maintained at the target hydraulic pressure Pt.

In the present embodiment, the servomotor SMh of the head side hydraulic circuit 22 and the servomotor SMr of the rod side hydraulic circuit 32 are operated based on the mode selected from the above three modes, respectively. The mode of the head-side hydraulic circuit 22 and the mode of the rod-side hydraulic circuit 32 may be the same or different. In the latter case, the position control mode is the main mode, the remaining modes are the subordinate modes, and the slide 15 is set to the target position St. In the following description, the mode of the head-side hydraulic circuit 22 and the mode of the rod-side hydraulic circuit 32 may be simply referred to as a head-side mode and a rod-side mode. In any case, each mode on the head side and the rod side is executed by the control of the servomotor SMh on the head side and the servomotor SMr on the rod side.

Next, the press molding cycle executed by this embodiment will be described.

To explain the outline of the cycle, when the servomotor SMh is driven to advance the rod 14, the slide 15 is pushed down together with the rod 14. Then, the upper die 16 attached to the slide 15 is pressed against the work W, and press molding is performed so that the work W is sandwiched between the upper die 16 and the lower die 17. Next, when the servomotor SMr is driven and the rod 14 is retracted, the slide 15 is pulled up together with the rod 14. Then, the upper die 16 attached to the slide 15 is separated from the work W, and the distance between the upper die 16 and the lower die 17 is increased to prepare for the next press molding. The press-molded work W is taken out from the mold, and the work W to be press-molded next is placed on the lower mold 17. The hydraulic cylinder mechanism 11 repeats this press forming cycle.

FIG. 5 is a diagram showing a press forming cycle, in which the horizontal axis represents time and the vertical axis represents the height position (actual position Sd or target position St) of the slide 15. The plurality of stages below the horizontal axis are the motion of the slide 15, the mode of the head side hydraulic circuit 22, the mode of the rod side hydraulic circuit 32, the control of the head side motor (servo motor SMh), and the rod. Each represents the control of the side motor (servo motor SMr). In the motion shown by the double circle and the single circle in FIG. 5, the head side hydraulic circuit 22 and the rod side hydraulic circuit 32 are simultaneously controlled in different modes. In the motion shown by the triangle in FIG. 5, a plurality of head-side hydraulic circuits 22 and rod-side hydraulic circuits 32 are simultaneously controlled in the same mode.

As the motion of the slide 15, first, it descends at high speed at times t1 to t3. The high-speed descent is realized by the position control mode of the head side hydraulic circuit 22 (control of the servomotor SMh). At this time, the rod-side hydraulic pressure circuit 32 is set to the counter pressure mode from the time t1 to the middle time t2, and is set to the low pressure pressure control mode from the next time t2 to the time t3 (control of the servomotor SMr). At time t1, the target command means 42 outputs a rotation speed control command to the servo amplifier A of the head side servomotor SMh, and outputs a switching command to torque control to the servo amplifier A of the rod side servomotor SMr. .. During this high-speed descent, the rod 14 moves at high speed, and the upper die 16 attached to the slide 15 comes into contact with the work W at time t3.

According to the present embodiment, since the rod-side hydraulic pressure circuit 32 is switched from the counter pressure mode to the pressure control mode at time t2, the effect of braking the descending speed of the slide 15 can be obtained, and the next (time t4). It is possible to quickly shift to a slow descent (after that). As a modification (not shown), the rod-side hydraulic circuit 32 may be set to the counter pressure mode from the high-speed descent start time t1 to the high-speed descent end time t3.

As the next motion of the slide 15, the pressure is lowered at times t3 to t4. At time t3, the target command means 42 continuously outputs a rotation speed control command to the servo amplifier A of the head-side servomotor SMh. The pressurization drop is realized by the pressure control mode of the head side hydraulic circuit 22 (control of the servomotor SMh). At this time, the rod-side hydraulic circuit 32 is put into the pressure control mode (control of the servomotor SMr). At time t4, the upper die 16 attached to the slide 5 comes into contact with the lower die 17, and the lowering of the slide 15 ends. In contrast to the high-speed descent described above, the advancing of the rod 14 at times t3 to t4 is a low-speed descent.

According to the present embodiment, since the rod-side hydraulic pressure circuit 32 is put into the pressure control mode before the time t3, the target command means 42 is connected to the servo amplifier A of the rod-side servomotor SMr at the time t3. There is no need to output a switching command from torque to rotation speed, enabling rapid changes in motion.

When the lower limit position of the slide 15 is not determined due to reasons such as the upper die 16 not contacting the lower die 17, the head side hydraulic pressure circuit 22 is continuously set to the position control mode after the time t3 (control of the servomotor SMh). The rod-side hydraulic pressure circuit 32 may be set to the pressure control mode (control of the servomotor SMr) to perform pressurization and lowering.

The next motion of slide 15 is held at times t4 to t5. The slide 15 stops during holding. At this time, the head-side servomotor SMh and the rod-side servomotor SMr are each set to the pressure control mode, and the slide 15 applies downward (advancing direction) pressure to the work W.

At times t1 to t5, the pushing force applied to the slide 15 by the hydraulic pressure of the head-side hydraulic chamber 12h is greater than or equal to the attractive force applied to the slide 15 by the hydraulic pressure of the rod-side hydraulic chamber 12r. Therefore, the position control mode on the head side is not hindered by the counter pressure mode and the pressure control mode on the rod side. The work W stabilizes at time t6, and the press molding executed at times t3 to t5 ends. The pushing force is the product of the hydraulic pressure and the pressure receiving area of the piston 13.

As the next motion of the slide 15, the pressure relief step is executed at times t5 to t6 to reduce the hydraulic pressure in the head side hydraulic chamber 12h. At this time, the head-side hydraulic circuit 22 and the rod-side hydraulic circuit 32 are each set to the pressure control mode. The depressurization step is a preparatory step for pulling up the slide 15 and returning the rod 14 to the original position, and the slide 15 is stopped.

As the next motion of the slide 15, the load increase is executed at times t6 to t7. At this time, the rod-side hydraulic circuit 32 is set to the position control mode (control of the servomotor SMr), and the slide 15 is pulled up at medium and low speeds. Further, the head side hydraulic circuit 22 is set to the pressure control mode (control of the servomotor SMh), and the slide 15 is suppressed from rising at a high speed as shown by the broken line. At time t6, the target command means 42 continuously outputs the rotation speed control to the servo amplifier A of the rod-side servomotor SMr. In contrast to the high-speed climb described below, the retreat of the rod 14 at times t6 to t7 is a slow rise.

As the next motion of slide 15, high-speed climbing is executed at times t7 to t8. At this time, the rod side is continuously put into the position control mode (control of the servomotor SMr), and the slide 15 is pulled up at high speed. Further, the head side is set to the counter pressure mode (control of the servomotor SMh), and the hydraulic pressure of the head side hydraulic chamber 12h is secured to some extent so that the pressure becomes equal to or higher than the atmospheric pressure. At time t7, the target command means 42 outputs a switching command to torque control to the servo amplifier A of the head side servomotor SMh, and subsequently outputs a rotation speed control command to the servo amplifier A of the rod side servomotor SMr. To do. During this high-speed climb, the rod 14 retreats at high speed. At time t8, the target command means 42 outputs a switching command to the rotation speed control to the servo amplifier A of the head side servomotor SMh, and continuously issues a rotation speed control command to the servo amplifier A of the rod side servomotor SMr. Output.

As the next motion of slide 15, stop or pause is executed at times t8 to t9. At this time, the rod side is continuously set to the position control mode (control of the servomotor SMr), and the slide 15 is maintained in the stopped state. In addition, the head side is set to the pressure control mode (control of the servomotor SMh).

At times t5 to t9, the attractive force applied to the slide 15 by the hydraulic pressure of the rod-side hydraulic chamber 12r is greater than or equal to the pushing force applied to the slide 15 by the hydraulic pressure of the head-side hydraulic chamber 12h. Therefore, the position control mode on the rod side is not hindered by the pressure and counter pressure modes on the head side.

At time t9, the press forming cycle consisting of the plurality of motions of slide 15 ends. After time t9, the present embodiment repeats the cycle of time t1 to t9 described above.

To give a schematic description of the cycle of this embodiment, first, the head-side hydraulic circuit 22 supplies hydraulic pressure to the head-side hydraulic chamber 12h to advance the rod 14 and push down the slide 15 (position control mode). At this time, the rod-side hydraulic circuit 32 adjusts the hydraulic pressure of the rod-side hydraulic chamber 12r (pressure control mode). Next, the rod-side hydraulic circuit 32 supplies hydraulic pressure to the rod-side hydraulic chamber 12r, retracts the rod 14, and pulls up the slide 15 (position control mode). At this time, the head-side hydraulic circuit 22 adjusts the hydraulic pressure in the head-side hydraulic chamber 12h (pressure control mode).

As described above, the press molding machine 10 of the present embodiment simultaneously executes different position control modes and pressure control modes to positively operate the piston 13 from the head side and the rod side of the hydraulic cylinder 12. It is possible to precisely control the position and moving speed of the slide 15 interlocked with the piston 13 and the pressure applied to the work W by the slide 15 and improve the responsiveness.

More specifically, the press molding machine 10 of the present embodiment controls the head side servomotor SMh or the rod side servomotor SMr so that the actual position Sd of the slide 15 interlocked with the rod 14 becomes the target position St. Position control mode (FIG. 2) and counter pressure mode that controls the head side servomotor SMh or rod side servomotor SMr so that the actual torque Td of the head side servomotor SMh or rod side servomotor SMr becomes the target torque Tt, respectively. (Fig. 3) and the head side servo so that the actual hydraulic pressure Pd of the head side hydraulic chamber 12h becomes the target hydraulic pressure Pt, or the actual hydraulic pressure Pd of the rod side hydraulic pressure chamber 12r becomes the target hydraulic pressure Pt. It includes a pressure control mode (FIG. 4) that controls the motor SMh or the rod-side servomotor SMr, respectively, and as shown by double circles and single circles in FIG. 5, the slide 15 has a high-speed lowering, a load increase, and a high-speed increase. In the stop motion, the head-side hydraulic circuit 22 and the rod-side hydraulic circuit 32 are simultaneously controlled in different modes among these three modes. As a result, one piston 13 can be precisely controlled by the two head-side hydraulic circuits 22 and the rod-side hydraulic circuit 32, and the actual positions Sd of the rod 14 and the slide 15 can be finely controlled from high-speed movement to low-speed movement. can do. Further, the pushing force applied to the work W when the work W is press-formed can be finely controlled. Further, the head-side pump Ph and the rod-side pump Pr can be used as general-purpose pumps, and the size of the press molding machine 10 can be increased at low cost.

Further, the motion controller MC of the present embodiment controls the head side in the position control mode and at the same time controls the rod side when advancing the rod 14 from the hydraulic cylinder 12 at times t1 to t2 shown by double circles in FIG. Control in counter pressure mode. As a result, the rod 14 can be moved at high speed to lower the slide 15 at high speed, and the press forming cycle is shortened.

Further, the motion controller MC of the present embodiment controls the head side in the position control mode and at the same time controls the rod side when moving the rod 14 from the hydraulic cylinder 12 at the time t2 to t3 shown by the double circle in FIG. Control in pressure control mode. As a result, it is possible to quickly shift to the next (time t3 to t4) pressurization descent motion.

Further, the motion controller MC of the present embodiment controls the rod side in the position control mode and at the same time pressurizes the head side when the rod 14 is retracted to the hydraulic cylinder 12 at times t6 to t7 shown by a single circle in FIG. Control in control mode. This makes it possible to precisely control the ascending speed of the slide 15 while pulling up the slide 15.

Further, the motion controller of the present embodiment controls the rod side in the position control mode and at the same time controls the head side when the rod 14 is retracted to the hydraulic cylinder 12 at times t7 to t8 shown by double circles in FIG. Control in pressure mode. As a result, the rod 14 can be retracted at a high speed to raise the slide 15 at a high speed, and the press forming cycle is shortened.

The embodiment shown in FIG. 1 includes one hydraulic cylinder mechanism 11 and a plurality of servomotors (specifically, two servomotors SMh and SMr) controlled by one motion controller MC. The press molding machine of the present invention is not limited to FIG. As a modification (not shown), the press molding machine is provided with a plurality of hydraulic cylinder mechanisms (for example, four) and twice as many servomotors SM (for example, eight), and one motion controller MC is provided for a plurality (for example, eight). The control signal may be output to the servo amplifiers A (8) at the same time. In a modified example (not shown), a plurality of hydraulic cylinder mechanisms provided at each corner of the slide 15 operate in the same manner, and the slide 15 is controlled in parallel.

Further, according to the press molding machine 10 of the present embodiment, the power consumption is reduced by downsizing and regenerative operation of the servomotors SMh and SMr. Therefore, energy saving can be achieved as compared with the conventional press molding machine.

To facilitate the understanding of the present invention, a supplementary explanation of the conventional press molding machine will be described. In the conventional press molding machine, the head side hydraulic circuit is driven by one electric motor, and the rod side hydraulic circuit is provided with a relief valve. It was provided. In particular, in a large press molding machine, one large motor is provided in the head side hydraulic circuit, and servo valves are provided in the head side hydraulic circuit and the rod side hydraulic circuit, respectively. Then, the head side hydraulic pressure and the rod side hydraulic pressure were generated while appropriately controlling the electric motor, the relief valve, and the servo valve. Then, in order to generate both the head side hydraulic pressure and the rod side hydraulic pressure, the electric motor had to be constantly driven by power running, and the power consumption was large.

On the other hand, according to the press molding machine 10 of the present embodiment, the relief valve and the servo valve are no longer indispensable, and one of the servomotors SMh and SMr is stopped or one of the servomotors SMh and SMr is regenerated. Since it can be operated, energy saving of the press molding machine 10 is realized.

Further, according to the press molding machine 10 of the present embodiment, since the relief valve and the servo valve are not indispensable, the structures of the hydraulic pressure circuits 22 and 32 are simplified and the maintenance is simplified.

Next, other embodiments of the present invention will be described. FIG. 6 is an overall view schematically showing a press molding machine according to another embodiment of the present invention. Regarding the other embodiments, the configurations common to the above-described embodiments are designated by the same reference numerals and the description thereof will be omitted, and the different configurations will be described below. The press molding machine 50 of another embodiment includes a hydraulic cylinder mechanism 51, a hydraulic circuit 21 that supplies hydraulic pressure to the hydraulic cylinder mechanism 51, and a motion controller MC that controls the hydraulic circuit 21. The hydraulic cylinder mechanism 51 has a plurality of hydraulic cylinders 52, 52 ..., The same number of pistons 53, 53 ..., And the same number of piston rods (hereinafter, simply referred to as rods 54). Each hydraulic cylinder 52 includes a push-side hydraulic chamber 52h or a pull-side hydraulic chamber 52r (both push-side hydraulic chambers are not provided).

The plurality of hydraulic cylinders 52, 52 ... Are arranged on the pulling direction side when viewed from the slider 15. The push-side hydraulic chamber 52h occupies the end of the hydraulic cylinder 52 on the head side, which is located on the opposite side of the rod 54 from the piston 53. The hydraulic cylinder 52 has a push-side hydraulic chamber 52h but does not have a pull-side hydraulic chamber. Of the ends of the hydraulic cylinder 52, the end on the rod 54 side when viewed from the piston 53 is the air chamber 52q. A communication hole 52j is formed in the hydraulic cylinder 52, and the air chamber 52q communicates with the outside world through the communication hole 52j to obtain atmospheric pressure.

Each push-side hydraulic chamber 52h is connected to the head-side passage 23 of the head-side hydraulic circuit 22. The head-side hydraulic circuit 22 is provided in each hydraulic cylinder 52.

The pull-side hydraulic chamber 52r occupies the end of the other hydraulic cylinder 52 on the rod side through which the rod 54 penetrates. The hydraulic cylinder 52 has a pull-side hydraulic chamber 52r but does not have a push-side hydraulic chamber. Of the ends of the hydraulic cylinder 52, the end on the head side, which is located on the side opposite to the rod 54 side when viewed from the piston 53, is the air chamber 52p. A communication hole 52j is formed in the hydraulic cylinder 52, and the air chamber 52p communicates with the outside world through the communication hole 52j to obtain atmospheric pressure.

Each pull-side hydraulic chamber 52r is connected to the rod-side passage 33 of the rod-side hydraulic circuit 32. The rod-side hydraulic circuit 32 is provided in each hydraulic cylinder 52.

The plurality of head-side hydraulic circuits 22 and the plurality of rod-side hydraulic circuits 32 are controlled by a common motion controller MC as described above. The press molding machine 50 shown in FIG. 6 can also finely control the position of the rod 54 of the hydraulic cylinder 52 like the press molding machine 10 of FIG. 1 described above, and is precise in a wide speed range from high speed to low speed. Controllable. Moreover, the press pressure can be finely controlled. Further, a general-purpose pump can be used for each of the pumps Ph and Pr, so that the press forming cycle can be increased and the size of the press forming machine can be increased.

Although FIG. 6 shows only one hydraulic cylinder 52 including the push-side hydraulic chamber 52h, the number of hydraulic cylinders 52 including the push-side hydraulic chamber 52h is not limited to this. When a plurality of hydraulic cylinders 52 including a push-side hydraulic chamber 52h are provided, the pushing force is the total force received by each of the plurality of pistons 53 from the head-side hydraulic circuit 22. Further, the number of hydraulic cylinders 52 including the pull-side hydraulic chamber 52r is not limited. The attractive force is the total force received by each of the plurality of pistons 53 from the rod-side hydraulic circuit 32.

Next, still another embodiment of the present invention will be described. FIG. 7 is an overall view schematically showing a press molding machine according to still another embodiment of the present invention. Further, with respect to the other embodiments, the configurations common to the above-described embodiments are designated by the same reference numerals and the description thereof will be omitted, and the different configurations will be described below. The press molding machine 60 of still another embodiment includes a hydraulic cylinder mechanism 61, a hydraulic circuit 21 that supplies hydraulic pressure to the hydraulic cylinder mechanism 61, and a motion controller MC that controls the hydraulic circuit 21. The hydraulic cylinder mechanism 61 has a plurality of hydraulic cylinders 55 in addition to the one or a plurality of hydraulic cylinders 52 described above. In addition to these, the hydraulic cylinder mechanism 61 has the same number of pistons 53, 56 and rods 54, 57 as the cylinders. Each hydraulic cylinder 52 includes a pushing side hydraulic chamber 52h, but does not include a pulling side hydraulic chamber. Each hydraulic cylinder 55 includes a pull-side hydraulic chamber 55h, but does not include a push-side hydraulic chamber. All hydraulic cylinders 52, 55 include a push-side or pull-side hydraulic chamber on the head side. The rod sides of all the hydraulic cylinders 52 and 55 are air chambers 52q and 55q.

The hydraulic cylinder 55 is arranged with respect to the slider 15 in a posture symmetrical to that of the hydraulic cylinder 52. Specifically, the hydraulic cylinder 52 is arranged above the slider 15 to push the slider 15, and the hydraulic cylinder 55 is arranged below the slider 15 to pull the slider 15. As described above, the hydraulic cylinders 52 and 55 have the same structure although the postures are symmetrical.

A communication hole 55j is formed in each hydraulic cylinder 55, and the air chamber 55q communicates with the outside world through the communication hole 55j to obtain atmospheric pressure. Each pull-side hydraulic chamber 55h is connected to a passage 33 of the pull-side hydraulic circuit 62. The pull-side hydraulic circuit 62 of 1 is commonly provided in a plurality of hydraulic cylinders 55, 55, ... The configuration of the pull-side hydraulic circuit 62 is the same as that of the rod-side hydraulic circuit 32 described above.

The hydraulic circuit 21 of the embodiment shown in FIG. 7 has a head-side hydraulic circuit 22 and a pull-side hydraulic circuit 62 as push-side hydraulic circuits. The head-side hydraulic circuit 22 (push-side hydraulic circuit) of 1 and the pull-side hydraulic circuit 62 of 1 are controlled by a common motion controller MC of 1 as described above. Like the press molding machines 10 and 50 described above, the press molding machine 60 shown in FIG. 7 can finely control the position of the rod 54 of the hydraulic cylinder 52 and the rod 57 of the hydraulic cylinder 55, and can be finely controlled from high speed to low speed. Precise control is possible in a wide speed range up to. Moreover, the press pressure can be finely controlled. Further, a general-purpose pump can be used for each of the pumps Ph and Pr, so that the press forming cycle can be increased and the size of the press forming machine can be increased.

Next, a modification of the present invention will be described. FIG. 8 is an overall view schematically showing a press molding machine which is a modification of the present invention, and is a modification of the embodiment shown in FIG. Regarding this modification, the same reference numerals will be given to the configurations common to the above-described embodiments, and the description thereof will be omitted, and different configurations will be described below. In the modified example of FIG. 8, the shaft 19 is arranged on the side opposite to the rod 14 with respect to the piston 13, that is, on the head side hydraulic chamber 12h. The hydraulic cylinder mechanism 11 of the modified example is also referred to as a double rod cylinder.

The shaft 19 is a round bar having a constant cross section extending straight and is coupled to the piston 13 at the end. The tip region 19t of the shaft 19 penetrates the other end of the hydraulic cylinder 12. As a modification (not shown), the position sensor 18 may detect the position of the tip region 19t. Alternatively, the tip of the shaft 19 may be connected to a mechanism (not shown).

In the modified example shown in FIG. 8, by making the cross-sectional area of the rod 14 equal to the cross-sectional area of the shaft 19, the pressure receiving area of the piston 13 can be made equal in the head side hydraulic chamber 12h and the rod side hydraulic chamber 12r. .. Therefore, the calculation of the above-mentioned three modes, particularly the pressure control mode, becomes easy.

Although the embodiments of the present invention have been described above with reference to the drawings, the present invention is not limited to the illustrated embodiments. It is possible to make various modifications and modifications to the illustrated embodiment within the same range as the present invention or within the same range. The servomotors SMh and SMr of this embodiment may be rotating electric machines connected to an inverter.

The present invention is advantageously used in stamping.

10,50,60 press molding machine, 11,51,61 hydraulic cylinder mechanism,
12, 52, 55 hydraulic cylinder, 12h head side hydraulic chamber,
12r rod side hydraulic chamber, 13,53,56 piston,
14,54,57 rods (piston rods), 15 slides,
16 Upper mold (mold), 17 Lower mold (mold), 18 Position sensor,
21 Hydraulic circuit, 22 Head side (push side) hydraulic circuit,
23 Head side passage, 24b, 24c, 34b, 34c hydraulic fluid tank,
25,35 hydraulic pressure sensor, 26,36 relief valve,
32, 62 Rod side (pull side) hydraulic circuit, 33 passage (rod side passage),
42 Target command means, 43 Control calculation unit, A Servo amplifier,
MC motion controller, P pump,
Ph head side pump, Pr rod side pump,
Pt target hydraulic pressure, Pd actual hydraulic pressure, SM servo motor,
SMh head side servo motor, SMr rod side servo motor,
Target position of St slide 15, etc., actual position of Sd slide 15,
Tt Target torque of the servo motor, actual torque Td of the servo motor.

Claims (7)

A hydraulic cylinder mechanism having at least one push-side hydraulic chamber and one pull-side hydraulic chamber partitioned by a hydraulic cylinder and a piston, and displaces a slider for molding in conjunction with the piston.
A push-side hydraulic circuit having a push-side pump and a push-side motor that is driven and coupled to the push-side pump and supplying a working fluid to the push-side hydraulic chamber.
A pull-side hydraulic circuit having a pull-side pump and a pull-side motor that is driven and coupled to the pull-side pump and supplies a working fluid to the pull-side hydraulic chamber.
A motion controller for controlling the push-side hydraulic circuit and the pull-side hydraulic circuit in one mode selected from a plurality of modes is provided.
The plurality of modes are
A position control mode that controls the push-side motor or the pull-side motor so that the actual position of the slider becomes the target slider position.
A pressure control mode that controls the push-side motor or the pull-side motor so that the actual hydraulic pressure in the push-side hydraulic chamber becomes the target hydraulic pressure or the actual hydraulic pressure in the pull-side hydraulic chamber becomes the target hydraulic pressure. When,
One of the total pushing force exerted by the one or more push-side hydraulic chambers on the piston and the total attractive force exerted by the one or more pull-side hydraulic chambers on the piston is smaller than the other. It includes a counter pressure mode in which the push-side motor or the pull-side motor corresponding to the one is operated to supply the counter hydraulic pressure to the push-side hydraulic chamber or the pull-side hydraulic chamber corresponding to the one. ,
A molding machine in which the push-side hydraulic circuit and the pull-side hydraulic circuit are simultaneously controlled in different modes among the plurality of modes. The pull-side hydraulic chamber and the push-side hydraulic chamber are the ends of the hydraulic cylinder on the rod side through which the rod to be coupled to the piston penetrates, and the side opposite to the rod when viewed from the piston. The molding machine according to claim 1, which occupies each end on the head side located in. When the rod is advanced from the hydraulic cylinder, the motion controller controls the push-side hydraulic circuit in the position control mode, and at the same time, controls the pull-side hydraulic circuit in the counter pressure mode or the pressure control mode. The molding machine according to claim 2, which is controlled. When the rod is retracted to the hydraulic cylinder, the motion controller controls the pull-side hydraulic circuit in the position control mode, and at the same time, controls the push-side hydraulic circuit in the counter pressure mode or the pressure control mode. The molding machine according to claim 2, which is controlled. A plurality of the hydraulic cylinders are arranged on the pulling direction side when viewed from the slider.
The push-side hydraulic chamber occupies the end of the hydraulic cylinder 1 located on the opposite side of the slider from the piston.
The molding machine according to claim 1, wherein the pull-side hydraulic chamber occupies the end of the other hydraulic cylinder on the slider side when viewed from the piston. The hydraulic cylinders are arranged on the push direction side and the pull direction side as viewed from the slider, respectively.
The push-side hydraulic chamber occupies the end of the hydraulic cylinder arranged on the pulling direction side, which is located on the side opposite to the slider when viewed from the piston.
The one according to claim 1, wherein the pull-side hydraulic chamber occupies an end of the hydraulic cylinder arranged on the pushing direction side, which is located on the opposite side of the slider when viewed from the piston. Molding machine. The push-side hydraulic circuit that supplies the hydraulic pressure in the push direction to the hydraulic cylinder and the pull-side hydraulic circuit that supplies the hydraulic pressure in the pull direction to the hydraulic cylinder are controlled in one mode selected from a plurality of modes. It's a method
The plurality of modes are
A position control mode that controls the push-side hydraulic circuit or the pull-side hydraulic circuit so that the actual position of the piston sliding in the hydraulic cylinder becomes the target position.
The push-side hydraulic circuit or the pull-side hydraulic circuit is operated so that the actual hydraulic pressure in the pushing direction becomes the target hydraulic pressure, or the actual hydraulic pressure in the pulling direction becomes the target hydraulic pressure. Pressure control mode to control and
The pushing side hydraulic pressure circuit corresponding to the one so that one of the total pushing force obtained by the hydraulic pressure in the pushing direction and the total pulling force obtained by the hydraulic pressure in the pulling direction is smaller than the other. Alternatively, the pull-side hydraulic pressure circuit includes a counter pressure mode for generating a counter hydraulic pressure.
A method for controlling a hydraulic circuit, wherein the push-side hydraulic circuit and the pull-side hydraulic circuit are simultaneously controlled in different modes among the plurality of modes.

Images