Press machine control device

Abstract

The present invention provides a control device for a press machine that facilitates the operation of moving a slide to a predetermined position. [Solution] A control device for a press machine comprising a slide that performs press working by reciprocating motion, a load supply unit that applies a load to the slide according to fluid pressure, and an operating unit operated by an operator to operate the slide, wherein the control device comprises a controller 42 that controls the load supply unit, and the controller 42 comprises a normal inching mode setting unit 44a that sets a normal inching mode in which the load supply unit is operated continuously and the slide is moved continuously while the operator is continuously operating the operating unit, and a pulse output mode setting unit 44b that sets a pulse output mode in which the load supply unit is operated intermittently and the slide is moved intermittently while the operator is continuously operating the operating unit.

Description

Technical Field

[0001] The present invention relates to a control device for a press machine that performs press working by reciprocating a slide.

Background Art

[0002] Press working such as drawing, bending, or shearing of various materials such as metals and non-metals is performed by lowering an upper die after setting the material on a lower die. The upper die is attached to the lower end of a slide provided on the press machine so as to be vertically movable, and the lower die is attached to the upper end of a bolster provided on the press machine. Therefore, when attaching a die including the upper die and the lower die, while positioning the upper die and the lower die in a state where the slide is lowered to the bottom dead center, the lower die is fixed to the bolster, and subsequently, the upper die is fixed to the slide.

[0003] On the other hand, in order to ensure safety, the press machine is configured such that when an operator performs an operation of lowering the slide, the slide moves only while the operator simultaneously operates two operation parts with both hands. That is, the moving amount of the slide is determined according to the operation time of the operation part. Therefore, conventionally, the slide has been moved to the bottom dead center as described above by an inching operation in which the position of the slide is finely adjusted while repeatedly operating the operation part for an extremely short time. Since such an inching operation is performed by the operator's sense, an operator with relatively low skill level has difficulty in the inching operation, and it takes time to move the slide to the bottom dead center, which may increase the working man-hours including the process of attaching the upper die and the lower die.

[0004] A setup inching device for moving the slide to the bottom dead center as described above is described in Patent Document 1. The setup inching device described in this Patent Document 1 is for an electric press machine that drives a slide by a servo motor, and is configured to output a command to move the slide by a distance proportional to a predetermined number of pulses corresponding to the magnitude of the operation rotation angle of a manual pulse generator to a servo amplifier.

Prior Art Documents

[0005] [Patent Document 1] Japanese Patent Application Publication No. 11-047995 [Overview of the project] [Problems that the invention aims to solve]

[0006] As described in Patent Document 1, in an electric press machine that uses a servo motor as a driving force source, the motor and the slide are always mechanically connected, so the position of the slide can be controlled by controlling the rotation angle of the motor. On the other hand, in a mechanical press machine that uses a motor to rotate a flywheel and has a clutch that connects the flywheel and the slide in a torque-transmitting manner when the operating part is operated, or in a fluid-pressure press machine that supplies fluid pressure such as hydraulic or pneumatic pressure to a cylinder when the operating part is operated to press the slide, the slide moves as the fluid pressure in the clutch or cylinder increases after the operating part is operated. Therefore, there is an unavoidable delay between operating the operating part and the start of slide movement due to factors such as the period during which the fluid pressure increases.

[0007] Therefore, in mechanical and fluid-pressure presses, if the operator operates the control unit and then visually confirms that the slide has started to move before ending the operation, the operation time may be too long, potentially causing the slide to move too far. Conversely, if the control unit is operated for a very short time, the sliding resistance of the slide may differ from press to press, potentially resulting in insufficient load being applied to the slide and preventing it from moving. As described above, mechanical and fluid-pressure presses do not have a function to control the drive source according to the position of the slide, making it difficult to move the slide to a predetermined position by inching. This requires time to attach the upper and lower dies, and there was room for improvement to enhance work efficiency.

[0008] The present invention has been made in view of the above technical problems, and aims to provide a control device for a press machine that can facilitate the operation of moving a slide to a predetermined position. [Means for solving the problem]

[0009] To achieve the above objective, the present invention provides a control device for a press machine comprising: a slide that performs press working by reciprocating motion; a load supply unit that applies a load to the slide according to fluid pressure; an operation unit that outputs a signal to operate the slide when operated by an operator; and a control valve that can switch between a supply position that supplies fluid pressure from a pressure source to the load supply unit based on a signal from the operation unit and a shut-off position that shuts off the supply of fluid pressure from the pressure source to the load supply unit, wherein the control device comprises a controller that controls the control valve, and the controller controls the operation While the unit is being operated by the operator, the operating unit The signal that is output No. Accordingly, the fluid pressure supplied to the load supply unit via the control valve is The system instructs the supply of fluid, and when the operator releases the operation of the control unit, it instructs the shutoff of the fluid pressure to the load supply unit via the control valve. A normal inching mode in which a command signal is output to the control valve, and the operation While the unit is being operated by the operator, in accordance with the signal output from the operation unit, The fluid pressure supply to the load supply unit via the control valve is repeatedly interrupted. Pulsating fingers The system is characterized by being configured to allow selection of a pulse output mode that outputs a command signal to the control valve.

[0010] In the present invention, the controller further comprises an inching mode setting unit for setting an inching mode for adjusting the slide to a predetermined position, and the pulse output mode is set on the condition that the inching mode is set by the inching mode setting unit. It is configured to be fixed good.

[0011] The present invention may further include an output mode switching operation unit for switching between the normal inching mode and the pulse output mode.

[0012] In the present invention, the controller, in the pulse output mode, the load supply Fluid pressure is supplied to the section. Operating time and the load supply The supply of fluid pressure to the section is cut off. height When the circuit is cut off The system may further include a pulse width setting unit for setting the interval between each pulse.

[0013] In the present invention, a motor as a driving force source, an inertial body rotated by the motor, a crankshaft connected to the slide and rotating to cause the slide to reciprocate, and a clutch mechanism that selectively switches between an engaged state in which the power of the inertial body is transmitted to the crankshaft and a released state in which the transmission of power between the inertial body and the crankshaft is interrupted, wherein the clutch mechanism comprises a cylinder to which fluid is supplied and a mechanism that supplies fluid pressure to the cylinder when energized The control bar The load supply unit may include the clutch mechanism. [Effects of the Invention]

[0014] The control device in this invention includes a normal inching mode setting unit that sets a normal inching mode in which the load supply unit that applies load to the slide is continuously operated while the operator is continuously operating the control unit, thereby continuously moving the slide, and a pulse output mode setting unit that sets a pulse output mode in which the load supply unit is intermittently operated while the operator is continuously operating the control unit, thereby intermittently moving the slide. Therefore, when fine-tuning the slide to a predetermined position, by setting the pulse output mode, the load supply unit can be operated intermittently to move the slide intermittently, and the slide can be moved by the same distance at all times without adjusting the operation time of the control unit. In other words, the amount of slide movement can be kept constant regardless of the operator's skill level or other subjective perceptions. Therefore, by setting the pulse output mode, it is only necessary to operate the control unit until the slide moves to the predetermined position, and the position of the slide can be easily adjusted to the predetermined position. As a result, the time required to move the slide to the predetermined position can be shortened, and work efficiency can be improved.

[0015] In addition, in the present invention, by configuring the widths of the operation time for operating the load supply unit and the stop time for stopping the load supply unit to be changeable respectively, regardless of the magnitude of the sliding resistance of the press machine or the like, the amount of movement of the slide in one pulse can be made constant, and it is possible to suppress an excess or deficiency in the amount of movement of the slide for each pulse.

Brief Description of the Drawings

[0016] [Figure 1] It is a schematic diagram for explaining an example of a press machine in an embodiment of the present invention. [Figure 2] It is a diagram showing a main part of an air circuit that supplies pneumatic pressure to a clutch mechanism and a brake mechanism. [Figure 3] It is a schematic diagram for explaining an example of a controller having an operation unit. [Figure 4] It is a block diagram for explaining an example of a control device that controls a press machine. [Figure 5] It is a flowchart for explaining a control example of moving a slide to an arbitrary position. [Figure 6] It is a time chart showing the presence or absence of an operation of an operation unit and the presence or absence of an output of current to a solenoid when a pulse output mode is set. [Figure 7] It is a diagram showing, by a crank angle, a region for setting a normal inching mode and a region for setting a pulse output mode when moving a slide to a bottom dead center. [Figure 8] It is a schematic diagram for explaining another example of a press machine in an embodiment of the present invention. [Figure 9] It is a diagram showing a main part of a hydraulic circuit that controls the hydraulic pressure of a cylinder.

Embodiments for Carrying Out the Invention

[0017] Next, embodiments of the present invention will be described with reference to the accompanying drawings. Note that the embodiments described below are merely examples of implementing the present invention and do not limit the present invention.

[0018] Figure 1 schematically shows an example of a press machine according to an embodiment of the present invention. The press machine 1 shown here can be configured in the same way as a conventional mechanical press machine. That is, it is equipped with a motor 2 as a driving force source, a flywheel 3 that is rotated by the motor 2 to store kinetic energy, a clutch mechanism 4 that transmits power from the flywheel 3 and also interrupts the transmission of that power, and a slide 5 that performs press work by reciprocating motion (up and down motion) due to the torque transmitted from the flywheel 3.

[0019] Motor 2 is mounted on the upper part of the housing 6 of the press machine 1 so that its output shaft 7 is horizontal. This motor 2 can be made up of a DC motor or an AC motor, and is configured to rotate at a predetermined rotational speed when power is supplied from a power source (not shown).

[0020] A relatively small-diameter drive-side pulley 8 is rotatably connected to the output shaft 7 of the motor 2. A flywheel 3, which is larger in diameter than the drive-side pulley 8, is provided below the drive-side pulley 8, parallel to the output shaft 7 of the motor 2 and in the vertical direction. Specifically, the flywheel 3 is provided alongside the upper side wall of the housing 6. A V-belt 9 is wrapped around the drive-side pulley 8 and the flywheel 3. Therefore, by rotating the flywheel 3 with the motor 2, kinetic energy corresponding to the inertia and rotational speed of the flywheel 3 is accumulated in the flywheel 3. This flywheel 3 corresponds to the "inertial body" in the embodiment of the present invention.

[0021] The flywheel 3 has a through hole, into which the drive shaft 10 is inserted so as to be rotatable relative to the flywheel 3. A clutch mechanism 4 is provided on the opposite side of the flywheel 3 from the housing 6, selectively connecting and disconnecting one end of the drive shaft 10 (the left end in Figure 1) to the flywheel 3.

[0022] This clutch mechanism 4 is composed of a friction-type clutch mechanism that can transmit torque corresponding to fluid pressure, such as hydraulic or pneumatic pressure, between the flywheel 3 and the drive shaft 10. Therefore, when fluid pressure is supplied, torque is transmitted between the flywheel 3 and the drive shaft 10, and when the fluid pressure decreases, the transmission of torque between the flywheel 3 and the drive shaft 10 is interrupted. The torque transmitted to the drive shaft 10 is transmitted as a load that moves the slide 5 up and down via the crankshaft 12, which will be described later. In other words, the clutch mechanism 4 is configured to apply a load corresponding to the fluid pressure to the slide 5, and corresponds to the "load supply unit" in the embodiment of the present invention.

[0023] This clutch mechanism 4 can be composed of, for example, a clutch cylinder 4a (described later), a piston (not shown) that moves back and forth within the clutch cylinder 4a and presses against a drive-side disc (described later), a drive-side disc that rotates integrally with the drive shaft 10 and is movable in the direction of the rotational axis of the drive shaft 10, and a driven-side disc that is rotatably connected to the flywheel 3 and positioned opposite the drive-side disc. In this configuration, the clutch mechanism 4 presses the piston by increasing the fluid pressure of the clutch cylinder 4a. When the piston is pressed and the drive-side disc and the driven-side disc come into contact, a torque corresponding to the frictional force is transmitted between the flywheel 3 and the drive shaft 10.

[0024] The drive shaft 10 is installed through the housing 6 and is supported by the housing 6 at both ends so that it can rotate. A pinion gear 11 is connected to the other end of the drive shaft 10 (the right end in Figure 1). A crankshaft 12 is positioned parallel to the drive shaft 10, and a main gear 13, which has a larger diameter than the pinion gear 11, is connected to the end of the crankshaft 12. The pinion gear 11 and the main gear 13 mesh together and transmit torque, amplifying the torque transmitted from the flywheel 3 to the drive shaft 10, which is then transmitted to the crankshaft 12.

[0025] A crank angle sensor 14, such as an encoder, is provided to detect the rotation angle of the crankshaft 12. The crank angle sensor 14 is set to "0" degrees when the crankpin 12a, which revolves around the rotational axis of the crankshaft 12, is at its highest point in the vertical direction. A display unit (not shown) is also provided to receive the signal detected by the crank angle sensor 14 and display the crank angle. For example, a mechanical display unit that is mechanically connected to the crankshaft 12 and rotates to indicate the crank angle may also be provided.

[0026] Furthermore, a brake mechanism 15 is attached to the drive shaft 10. This brake mechanism 15 is configured to stop the rotation of the drive shaft 10 by applying a braking torque to it. For example, the brake mechanism 15 consists of a disc that rotates integrally with the drive shaft 10 (not shown), a housing and piston positioned on either side of the disc, and a spring that constantly presses against the piston. A pneumatic chamber is formed so that when air pressure is supplied, a load is applied to move the piston away from the disc.

[0027] Therefore, for example, if the power to the press machine 1 is turned off, or if the operating unit 37 described later is not operated, and the conditions for moving the slide 5 are not met, air is discharged from the pneumatic chamber, causing the piston to contact the disc and applying braking torque to the drive shaft 10. Conversely, if the conditions for moving the slide 5 are met, such as when the operating unit 37 is operated, air is supplied to the pneumatic chamber to increase the air pressure, separating the piston from the disc and releasing the brake on the drive shaft 10.

[0028] In other words, when the clutch mechanism 4 interrupts the transmission of torque between the flywheel 3 and the drive shaft 10, the brake mechanism 15 constantly prevents the rotation of the drive shaft 10. Conversely, when the clutch mechanism 4 allows torque to be transmitted between the flywheel 3 and the drive shaft 10, the brake of the brake mechanism 15 is released, allowing the drive shaft 10 to rotate. In short, the clutch mechanism 4 and the brake mechanism 15 are configured to operate in conjunction with each other. However, as long as the clutch mechanism 4 and the brake mechanism 15 can operate in conjunction with each other, the configuration of the brake mechanism 15 is not particularly limited.

[0029] A connecting rod 16 is connected to the crank pin 12a described above. Therefore, as the crankshaft 12 rotates, the connecting rod 16 moves up and down in the vertical direction.

[0030] An adjustment screw 18 for adjusting the position of the upper die 17 at the bottom dead center, as described later, is screwed into the lower end of the connecting rod 16. Therefore, by increasing the amount the adjustment screw 18 is screwed into the connecting rod 16, the position of the upper die 17 at the bottom dead center can be moved upward, and by decreasing the amount of screwing, the position of the upper die 17 at the bottom dead center can be moved downward.

[0031] A slide 5 is connected to the lower end of the adjustment screw 18 so as to move up and down together with the adjustment screw 18. As described above, the adjustment screw 18 operates together with the connecting rod 16, so as the crankshaft 12 rotates, the upper ends of the connecting rod 16 and the adjustment screw 18 tilt with respect to the vertical. For this reason, the lower end of the adjustment screw 18 is formed in a spherical shape, and the upper end of the slide 5 is formed so as to engage with the lower end of the adjustment screw 18 in the vertical direction.

[0032] The lower end of the slide 5 is provided with a mounting portion (not shown) for fixing the upper mold 17, and the upper mold 17 is fixed to this mounting portion by bolts or the like. Furthermore, a slide gib 19 is provided on the inner surface of the housing 6 to guide the outer surface of the slide 5.

[0033] Furthermore, the housing 6 is provided with a bed section 6a facing the lower end surface of the slide 5, and a bolster 20 is fixed to its upper surface. The lower die 21 is fixed to the upper surface of the bolster 20 by bolts or the like. A detection unit, such as an optical sensor (not shown), is provided on the front of the press machine 1 to detect whether a hand or part of the body is inside the press machine 1. In addition, in the example shown in Figure 1, a housing section 22 for housing a control device, electrical circuit, or pneumatic circuit, which will be described later, is attached to the side of the housing 6.

[0034] Figure 2 shows the main components of an air circuit that controls the air pressure of a clutch cylinder 4a for switching between an engaged state in which the clutch mechanism 4 transmits torque and a released state in which the transmission of torque is interrupted, and a brake cylinder 15a for applying braking torque to the drive shaft 10 by the brake mechanism 15, or for releasing that braking torque. In the example shown in Figure 2, an air pressure source 23, a regulator valve 24, a pressure switch 25, a lubricator 26, and a double solenoid valve 27 are included.

[0035] The air pressure source 23 compresses and outputs air, and can be constructed using a conventional compressor or the like. The regulator valve 24 is configured to adjust the output air pressure to a predetermined pressure. Specifically, the regulator valve 24 is configured to connect the output flow path 28 and the air pressure source 23 when the output air pressure is less than the predetermined pressure, and to shut off the flow path 28 and the air pressure source 23 when the air pressure is equal to or greater than the predetermined pressure.

[0036] The flow path 28 on the output side of the regulator valve 24 is equipped with a pressure gauge 29 for detecting the output pressure and a pressure switch 25 that switches according to the output pressure of the regulator valve 24. Furthermore, in order to reduce the sliding resistance of components such as the spool 30 that constitute the double solenoid valve 27, which will be described later, the flow path 28 is equipped with a lubricator 26 that mixes lubricating oil into the air in the flow path 28.

[0037] A double solenoid valve 27 is provided on the output side of the lubricator 26. This double solenoid valve 27 has two valve bodies (not shown) formed with an input port 31 communicating with a flow path 28, a drain port 32 for discharging air, and an output port 33 communicating with the clutch cylinder 4a and the brake cylinder 15a. Each of these valve bodies is provided with a spool 30 that switches between a brake position, which reduces the air pressure in the clutch cylinder 4a and the brake cylinder 15a by moving upward on the plane of the paper, closing the input port 31 and communicating the drain port 32 and the output port 33, and a movable position, which fills the air pressure in the clutch cylinder 4a and the brake cylinder 15a to a specified pressure or supplies air pressure by moving downward on the plane of the paper, closing the drain port 32 and communicating the input port 31 and the output port 33.

[0038] To move the spool 30 up and down, or in other words, to fill or supply air pressure to the clutch cylinder 4a and the brake cylinder 15a, a solenoid 34 is provided that presses the spool 30 to a movable position by electromagnetic force, and a spool spring 35 is provided that applies spring force to the spool 30 to move the spool 30 to the brake position.

[0039] Therefore, by energizing the solenoid 34 and moving the spool 30 downward (to the movable position), the air pressure regulated by the regulator valve 24 can be supplied to the clutch cylinder 4a and the brake cylinder 15a, thereby filling the clutch cylinder 4a and the brake cylinder 15a with air pressure. Conversely, by stopping the power supply to the solenoid 34 and moving the spool 30 upward (to the brake position), air can be discharged from the clutch cylinder 4a and the brake cylinder 15a. In other words, by controlling whether or not current flows through the solenoid 34, the clutch mechanism 4 and the brake mechanism 15 can be engaged or disengaged.

[0040] As mentioned above, the clutch mechanism 4 and the brake mechanism 15 operate in conjunction, and when moving the slide 5, air pressure is supplied to the clutch cylinder 4a and the brake cylinder 15a. Therefore, considering the mounting requirements, such as the location where the clutch mechanism 4 and the brake mechanism 15 are placed, the clutch cylinder 4a and the brake cylinder 15a may be combined into a single cylinder. Furthermore, for example, to match the time required from when the solenoid 34 is energized until the clutch mechanism 4 begins to transmit torque with the time required until the brake mechanism 15 finishes releasing the braking torque, a throttle valve or the like may be provided in the path from the output port 33 to either cylinder 15a (4a), and the amount of throttle may be adjusted in advance.

[0041] Furthermore, a controller 36 for operating the press machine 1 is provided on the front side of the press machine 1. Figure 3 schematically shows an example of the controller 36. This controller 36 has two operating parts 37 that are operated by the operator to operate the slide 5 and also to restrain the operator's hands. These operating parts 37 are spaced apart to the extent that the operator needs to use both hands to operate them. The operating parts 37 can be configured as button-type operating parts 37 that input an ON signal to a control device described later when pressed. Alternatively, it may be an operating part 37 using an optical sensor that has a light-emitting element and a light-receiving element, and inputs an ON signal to a control device described later when the space between these elements is shielded.

[0042] Furthermore, the controller 36 is provided with an output mode switching operation unit 38 for switching to the pulse output mode, which will be described later. This output mode switching operation unit 38 may be a button, a toggle, or a rotary. In the example shown in Figure 3, the output mode switching operation unit 38 is provided between the operation units 37, but the position of the output mode switching operation unit 38 is not particularly limited. The controller 36 shown in Figure 3 also has an emergency stop button 39 for emergency stopping, provided between each operation unit 37 and above the output mode switching operation unit 38.

[0043] The aforementioned storage unit 22 is provided with an operating mode switching unit 40 for switching between a processing mode and an inching mode. This processing mode is a mode set when processing a product, and in the following description, the safe single-pass mode used when an operator processes a product by operating the operating unit will be used as an example. The processing mode may also be a continuous operation mode in which the slide 5 is automatically moved in cooperation with a feeding device that transports a workpiece such as a coil material, and the operating mode switching unit 40 may be configured to switch between the safe single-pass mode, the continuous operation mode, and the inching mode. Furthermore, the operating mode switching unit 40 may also have a function to switch the power of the press machine 1 on and off.

[0044] When the safe single-stroke mode is selected, operating the control unit 37 will cause the slide 5 to move from the top dead center to the bottom dead center, and then automatically move from the bottom dead center to the top dead center. In other words, the slide 5 completes one stroke. Even if you continue to operate the control unit 37 when the slide 5 has moved to the top dead center, the slide 5 will remain stopped at the top dead center until you release the control unit 37 and operate it again. If you release the control unit 37 while the slide 5 is descending from the top dead center to the bottom dead center, the slide 5 will stop abruptly. Conversely, if the slide 5 is ascending from the bottom dead center to the top dead center, the slide 5 will automatically move to the top dead center even if you release the control unit 37.

[0045] The inching mode is set when the slide 5 needs to be moved to an arbitrary position. For example, if the slide 5 comes to a sudden stop due to the emergency stop button 39 being operated or an abnormality being detected while the slide 5 is being moved in the safe single-pass mode, the inching mode is set to move the slide 5 to the top dead center. One of the conditions for executing the safe single-pass mode is that the slide 5 must be at the top dead center. The inching mode is also set when attaching the upper die 17 and lower die 21 to the press machine 1, to move the slide 5 to a target position for attaching the upper die 17 and lower die 21, such as the bottom dead center or a position a predetermined angle before the bottom dead center. Alternatively, when the press machine 1 is used to perform press processing automatically on a production line without operator intervention, the press machine 1 needs to operate in conjunction with a feed device and air ejector that transport workpieces such as coil material. Therefore, the inching mode is set to move the slide 5 to an arbitrary position during production line startup or adjustment.

[0046] Furthermore, since the inching mode is a mode for adjusting the position of slide 5, unlike the safe single-stroke mode described above, if you release your hand from the operating unit 37 while slide 5 is moving from the bottom dead center to the top dead center, slide 5 will stop at that position. In other words, slide 5 does not automatically move to the top dead center. Also, even if slide 5 moves to the top dead center while the operating unit 37 is being operated, if you continue to operate the operating unit 37, slide 5 will descend without stopping at the top dead center.

[0047] As described above, the inching mode is the mode set when moving the position of the slide 5 to the target position. Therefore, for example, if the slide 5 is configured to move continuously while the operating unit 37 is being operated, it is necessary to perform inching operations by repeatedly turning the operating unit 37 on and off in a short period of time. On the other hand, due to factors such as the time it takes for the air pressure of the clutch cylinder 4a and brake cylinder 15a to increase after starting to operate the operating unit 37, there is an unavoidable delay between the timing of the operation and when the slide 5 starts to move. For similar reasons, there is an unavoidable delay between finishing the operation of the operating unit 37 and when the slide 5 stops. Therefore, if you release your hand from the operating unit 37 after visually confirming that the slide 5 has started to move, the amount of movement of the slide 5 may be greater than the intended amount.

[0048] On the other hand, the press machine 1 has unavoidable sliding resistance. Furthermore, the press machine 1 may have, for example, an upper die 17 equipped with a punch that presses or punches out the product and a stripper that clamps a part of the product between the upper die 17 and the lower die 21 to separate the product from the punch or to suppress the product from warping when the product is pressed. Such a stripper is suspended from the upper die 17 and is configured to move relative to the punch and the stripper by providing a compression spring between it and the base of the upper die 17. Therefore, when processing the product, after the stripper clamps a part of the product between itself and the lower die 21, the slide 5 descends while compressing the compression spring. That is, after the stripper has come into contact with the product, a reaction force acts on the slide 5.

[0049] Therefore, if the operating section 37 is operated for only a very short time, the air pressure in the clutch cylinder 4a may not increase to a pressure that can transmit a greater power than the sliding resistance and reaction force from the flywheel 3 to the drive shaft 10, or the air pressure in the brake cylinder 15a may not increase to a pressure that reduces the braking torque of the brake mechanism 15. As a result, the torque transmitted to the crankshaft 12 may be insufficient, causing the slide 5 to not move or to move only a very small amount.

[0050] Therefore, the control device for the press machine in the embodiment of the present invention is configured to allow switching between two inching modes: a normal inching mode in which the slide 5 is continuously moved by continuously supplying current to the solenoid 34 while the operation unit 37 is being operated to continuously operate the clutch mechanism 4 (i.e., maintain the engaged state); and a pulse output mode in which the slide 5 is intermittently moved by supplying pulsed current to the solenoid 34 while the operation unit 37 is being operated to intermittently operate the clutch mechanism 4 and the brake mechanism 15 (i.e., repeatedly switching between the engaged state and the released state). Specifically, when the inching mode is set by the operation mode switching operation unit 40, the normal inching mode and the pulse output mode can be switched by switching the output mode switching operation unit 38. In other words, the normal inching mode and the pulse output mode can be set on the condition that the inching mode is set.

[0051] A programmable logic controller (hereinafter referred to as PLC) 42 for setting the pulse output mode described above and controlling the current supplied to the solenoid 34 when the pulse output mode is set, in other words, for controlling the clutch mechanism 4 and the brake mechanism 15, is provided, for example, in the housing 22 of the press machine 1. This PLC 42 corresponds to the "controller" in the embodiment of the present invention and is mainly composed of relay circuits and a microprocessor. Figure 4 shows a block diagram illustrating the functional configuration of the PLC 42. The PLC 42 shown in Figure 4 is electrically connected to an operation unit 37, an output mode switching operation unit 38, an operation mode switching operation unit 40, a crank angle sensor 14, and a detection unit, and is configured to control the current supplied to the solenoid 34 based on the operating position of these operation units 37, etc. Note that the control devices for the clutch mechanism 4 and the brake mechanism 15 may be configured to control the current supplied to the solenoid 34 by the coordinated operation of control devices provided in the press machine 1 and the controller 36, respectively.

[0052] The PLC 42 shown in Figure 4 includes an operating mode determination unit 43, an instability mode setting unit 44, a simultaneous operation determination unit 45, an operating condition determination unit 46, a pulse width setting unit 47, and an output unit 48. The operating mode determination unit 43 determines whether one of the selectable operating modes, such as processing mode or instability mode, is selected based on the signal input from the operating mode switching operation unit 40. The operating mode switching operation unit 40 includes, for example, a relay corresponding to the selected operating mode, and the operating mode determination unit 43 determines the operating mode selected by the operator based on which relay the signal is input from.

[0053] The inching mode setting unit 44 sets the inching mode when the operating mode switching operation unit 40 is in the position for setting the inching mode. For example, the inching mode setting unit 44 sets the inching mode by receiving a signal from a relay that becomes conductive when the operating mode switching operation unit 40 is in the position for selecting the inching mode.

[0054] The inching mode setting unit 44 further comprises a normal inching mode setting unit 44a and a pulse output mode setting unit 44b. The normal inching mode setting unit 44a sets the normal inching mode when the output mode switching operation unit 38 is in the "off" position. For example, the output mode switching operation unit 38 includes a relay that is conductive when in the "on" position, and the normal inching mode setting unit 44a sets the normal inching mode when that relay is de-energized. The pulse output mode setting unit 44b sets the pulse output mode when the output mode switching operation unit 38 is in the "on" position. In other words, the pulse output mode setting unit 44b sets the pulse output mode when that relay is conductive.

[0055] The simultaneous operation determination unit 45 determines whether each operation unit 37 is being operated and whether each operation unit 37 has started to be operated simultaneously. For example, it includes a relay that becomes conductive when the right operation unit 37 in Figure 3 is operated and a relay that becomes conductive when the left operation unit 37 is operated, and determines whether each operation unit 37 is being operated based on whether each relay is ON or OFF. It also determines whether each operation unit 37 has started to be operated simultaneously based on whether the time between one relay turning ON and the other relay turning ON is within a predetermined time. For example, it starts counting when a signal is input from one relay and determines whether the other relay turned ON before the count reaches a limit count.

[0056] The operating condition determination unit 46 determines whether or not the conditions that prohibit the operation of the press machine 1 have been met. For example, it determines whether or not the detection unit has detected that a hand or part of the body is not inside the press machine 1, or in other words, whether or not the light receiving element has detected light from the light emitting element of the optical sensor. Also, as mentioned above, the safe single-stroke mode requires that the slide 5 be at top dead center as an execution condition, so when the safe single-stroke mode is set, it determines whether or not the crank angle (for example, ±3°) is within a predetermined range in which the slide 5 can be determined to be at top dead center.

[0057] The pulse width setting unit 47 is configured to set the energizing time (i.e., the operating time for operating the clutch mechanism 4) and the de-energizing time (i.e., the de-energizing time for stopping the clutch mechanism 4) when a pulsed current is supplied to the solenoid 34 by the pulse output mode. Specifically, it is equipped with a variable resistor for setting the energizing time, and the operator operates the variable resistor in advance to set the resistance value, and energizes the solenoid 34 for a time corresponding to that resistance value. Similarly, it is equipped with a variable resistor for setting the de-energizing time, and the operator operates the variable resistor in advance to set the resistance value, and does not energize the solenoid 34 for a time corresponding to that resistance value. In other words, the energizing time and de-energizing time are set individually. Note that the hydraulic response and sliding resistance differ for each press machine 1, and the reaction force of the mold also differs, so the resistance value corresponding to the desired amount of slide 5 movement is set in advance by setting the pulse output mode and operating the press machine 1 in advance.

[0058] The output unit 48 outputs a current to the solenoid 34 according to the set operating mode, such as the safe single-stroke mode, the normal inching mode, or the pulse output mode. Specifically, when the safe single-stroke mode is set, for example, current is continuously supplied to the solenoid 34 for the duration of one stroke of the slide 5. When the normal inching mode is set, for example, current is continuously supplied to the solenoid 34 for the duration that the operating unit 37 is operated. When the pulse output mode is set, pulsed current is supplied to the solenoid 34 for the duration that the operating unit 37 is operated, according to the energized and de-energized times determined by the pulse width setting unit 47.

[0059] Figure 5 shows a flowchart illustrating an example of control for inching the slide 5. In the control example shown in Figure 5, first, it is determined whether the position of the output mode switching operation unit 38 is the position for setting the pulse output mode (i.e., "on") (step S1). This step S1 can be determined, for example, based on whether a signal has been input from a relay that becomes conductive when the position of the output mode switching operation unit 38 is "on".

[0060] If a negative result is determined in step S1 because the output mode switching operation unit 38 is not in the position for setting the pulse output mode, the normal output mode is set (step S2), and this routine is terminated. This normal output mode is the same as that of a conventional press machine, and is the operating mode according to the operating position of the operating mode switching operation unit 40. That is, if the position of the operating mode switching operation unit 40 is the safe single-stroke mode, the operation unit 37 is operated to move the slide 5 by one stroke, and if the position of the operating mode switching operation unit 40 is the inching mode, the slide 5 is moved while the operation unit 37 is being operated.

[0061] Conversely, if it is determined positively in step S1 that the output mode switching operation unit 38 is in the position for setting the pulse output mode, then it is determined whether or not the operation mode switching operation unit 40 is in the position for setting the instance mode (step S3). This step S3 can be determined, for example, based on the signal of the relay that becomes conductive when it is in the position for setting the instance mode, as described above.

[0062] If the position of the operating mode switching control unit 40 is not the position for setting the inching mode, and this is determined negatively in step S3, the output OFF mode is set (step S4), and this routine is terminated. This output OFF mode is a mode that rejects operation of the control unit 37, and therefore, even if the control unit 37 is operated, the solenoid 34 is not energized and the slide 5 does not move.

[0063] Conversely, if it is determined in step S3 that the position of the operating mode switching operation unit 40 is the position for setting the instability mode, then the pulse output mode is set (step S5). Next, it is determined whether or not the operation unit 37 is being operated (step S6). This step S6 can be performed by the simultaneous operation determination unit 45, which determines whether or not each operation unit 37 is started to be operated simultaneously and whether or not the operated state is maintained. For example, it determines whether or not one relay is turned on and the other relay is turned on within a predetermined time after the other relay is turned on, and whether or not each relay remains in the on state.

[0064] If at least one of the operating units 37 is not being operated, or if both operating units 37 have not started to be operated simultaneously, a negative determination is made in step S6. If a negative determination is made in step S6, the routine is terminated without energizing the solenoid 34, i.e., without moving the slide 5, because operating the press machine 1 could be dangerous. Conversely, if a positive determination is made in step S6 because both operating units 37 have started to be operated simultaneously and continue to be operated, it is determined whether the conditions for prohibiting the operation of the press machine 1 have been met (step S7). This step S7 can be determined by the operating condition determination unit 46.

[0065] If the prohibition condition is met and a positive result is determined in step S7, the routine is terminated without energizing the solenoid 34, i.e., without moving the slide 5, because operating the press machine 1 could be dangerous. Conversely, if the prohibition condition is not met and a negative result is determined in step S7, the routine is terminated by energizing the solenoid 34 with a pulsed current corresponding to the set energizing and de-energizing times (step S8).

[0066] Figure 6 is a time chart showing the current supplied to the solenoid 34 when the pulse output mode is set and the operating unit 37 is operated. At time t0 in Figure 6, the solenoid 34 is not energized because the operating unit 37 is not operated. Therefore, the spool 30 is pressed by the spool spring 35, closing the input port 31 and connecting the drain port 32 and the output port 33, thereby reducing the air pressure of the clutch cylinder 4a and the brake cylinder 15a to the brake position. Consequently, the air pressure of the clutch cylinder 4a and the brake cylinder 15a is maintained at an unloaded state. As a result, the clutch mechanism 4 is in a released state, disconnecting the drive shaft 10 from the flywheel 3, and the flywheel 3 is in a free-spinning state. Also, since the drive shaft 10 is fixed by the brake mechanism 15, the slide 5 does not move.

[0067] At time t1, the operating unit 37 is operated, and then at time t2, the solenoid 34 is energized. As a result, the spool 30 is pressed by electromagnetic force, closing the drain port 32 and connecting the input port 31 and the output port 33, which brings the clutch cylinder 4a and the brake cylinder 15a into a movable position for filling them with air. Consequently, the air pressure in the clutch cylinder 4a and the brake cylinder 15a increases to the specified pressure. As a result, the drive shaft 10 and the flywheel 3 are connected via the clutch mechanism 4, and torque is transmitted to the drive shaft 10. Also, the slide 5 moves to release the brake mechanism 15 from fixing the drive shaft 10. The delay between time t1 and time t2 is the delay time from when the operating unit 37 is operated until the relay switches on.

[0068] From time t2 onward, the operating unit 37 is continuously operated. As a result, a pulsed current based on the energizing time A and de-energizing time B set by the variable resistor is supplied to the solenoid 34. Therefore, the engaged and disengaged states of the clutch mechanism 4 and the brake mechanism 15 are repeatedly switched, causing the slide 5 to move intermittently.

[0069] Furthermore, since the response time until the air pressure in the clutch cylinder 4a and brake cylinder 15a increases, and the magnitude of the sliding resistance when driving the slide 5 differ for each press machine 1, this energizing time A is pre-adjusted according to the press machine 1 so that, for example, it is the time it takes for the crankshaft 12 to rotate by a predetermined angle (for example, 1°) in one pulse, that is, the time it takes for the slide 5 to move by a predetermined amount.

[0070] Furthermore, as described above, since the clutch mechanism 4 is engaged from a state where the flywheel 3 is rotating and the drive shaft 10 is stopped by the brake mechanism 15, slippage occurs in the clutch mechanism 4 when it begins to engage, and the clutch mechanism 4 generates heat in accordance with this slippage. Therefore, repeatedly engaging and disengaging the clutch mechanism 4 may reduce its durability. Similarly, since the brake mechanism 15 begins to apply braking torque by contacting the rotating disc, repeatedly engaging and disengaging the brake mechanism 15 may reduce its durability.

[0071] Therefore, the non-energized time B is pre-adjusted based on the amount of heat dissipated by allowing the flywheel 3 (non-drive side disc) to spin freely with the clutch mechanism 4 released, and the heat capacity of the clutch mechanism 4, or based on the amount of heat dissipated by the disc with the brake mechanism 15 released, and the heat capacity of the brake mechanism 15. The non-energized time B may also be set to a time such that the slide 5 temporarily stops, allowing the operator to determine whether the stopped position is the position requested by the operator.

[0072] If the operation of the control unit 37 is completed at time t3, the solenoid 34 will be de-energized at time t4, which is a short delay from time t3, as described above. Furthermore, as shown in Figure 6, even if the relay is turned off while the solenoid 34 is energized, the solenoid 34 will be switched to the de-energized state at that point (before the energizing time A is completed).

[0073] Figure 7 shows, using crank angles, the regions I for setting the normal inching mode and P for setting the pulse output mode when moving the slide 5 from top dead center to bottom dead center to attach the upper die 17 and lower die 21. As shown in Figure 7, the movement from top dead center to a predetermined angle is performed using the normal inching mode. That is, the operation mode switching unit 40 is operated to the position for setting the inching mode, and the output mode switching unit 38 is operated to the "off" position, and in that state, the operation unit 37 is operated with both hands simultaneously. The reason for setting the normal inching mode in region I in this way is that intermittently moving the slide 5 takes time, it is not a region for fine-tuning the position of the slide 5, and it suppresses a decrease in the durability of the clutch mechanism 4 and brake mechanism 15. On the other hand, since the control device of this press machine 1 fine-tunes the position of the slide 5 to bottom dead center using the pulse output mode, the positional accuracy of the slide 5 is not required in the normal inching mode. Therefore, the switching position between the normal inching mode and the pulse output mode can be arbitrarily determined by the operator while visually confirming.

[0074] Then, after the slide 5 has descended to its predetermined position, the operator releases both hands from the control unit 37 and operates the output mode switching control unit 38 to switch to pulse output mode. After that, by operating the control unit 37 again simultaneously with both hands, a continuous pulsed current is supplied to the solenoid 34, causing the slide 5 to descend by a predetermined amount at predetermined intervals.

[0075] As described above, while the operating unit 37 is being operated, a pulsed current is supplied to the solenoid 34 to intermittently move the slide 5, allowing the slide 5 to be moved by the same distance at all times without adjusting the operating time of the operating unit 37. In other words, the amount of movement of the slide 5 can be kept constant, regardless of the operator's skill level or other subjective judgment. Therefore, by operating the operating unit 37 while checking the crank angle displayed on the display unit until the slide 5 moves to the bottom dead center (target position), the position of the slide 5 can be easily adjusted to the target position such as the bottom dead center. As a result, the time required to install the upper mold 17 and the lower mold 21 can be shortened, and work efficiency can be improved. The above target position includes, for example, the position of the slide 5 required when starting up or adjusting the production line.

[0076] Furthermore, by configuring the energized time and de-energized time to be adjustable, for example, the amount of movement of slide 5 in one pulse can be kept constant regardless of the magnitude of the sliding resistance, and any excess or deficiency in the amount of movement of slide 5 in each pulse can be suppressed.

[0077] The press machine in the embodiment of the present invention is not limited to the above configuration, and may, for example, be configured to transmit torque from the flywheel 3 to the crankshaft 12 without providing a drive shaft 10. Alternatively, the crankshaft 12 may be provided with a plurality of crankpins 12a, and a connecting rod 16 may be connected to each crankpin 12a to press the slide 5 at multiple points. Furthermore, the press machine 1 only needs to be configured to apply a load to the slide 5 according to the fluid pressure, and is not limited to a configuration that controls the torque transmitted by the clutch mechanism 4, but may also be a fluid pressure press machine 1 that presses the slide 5 according to the fluid pressure of the cylinder.

[0078] Figure 8 shows a schematic diagram illustrating an example of a hydraulic press machine as a press machine in an embodiment of the present invention. The press machine 1 shown in Figure 8 mainly comprises a main cylinder 49, side cylinders 50 provided on both sides of the main cylinder 49, a slide 5, and a hydraulic pump 51 which serves as the hydraulic power source for each cylinder 49, 50.

[0079] In the example shown in Figure 8, an electrically driven hydraulic pump 51 is provided on the upper part of the housing 6 of the press machine 1. This hydraulic pump 51 pressurizes the oil stored in the oil tank 52 and supplies it to each cylinder 49, 50. This hydraulic pump 51 can be configured in the same way as the hydraulic pumps provided in conventional hydraulic presses.

[0080] A valve unit 53 is connected to the hydraulic pump 51 described above. Figure 9 shows the main parts of the hydraulic circuit that controls the hydraulic pressure of the main cylinder 49 and the side cylinder 50. Note that the configuration for controlling the hydraulic pressure of the main cylinder 49 and the side cylinder 50 can be the same, so in the following explanation, the configuration for controlling the hydraulic pressure of the main cylinder 49 will be used as an example.

[0081] In the example shown in Figure 9, an electric hydraulic pump 51 driven by a motor 54 is provided, and a strainer 56 is provided in the oil passage 55 on the input side of the pump. This strainer 56 is configured to remove foreign matter mixed in with the oil pumped up by the hydraulic pump 51.

[0082] A relief valve 59 is provided in the output oil passage (hereinafter referred to as the output oil passage) 57 of the hydraulic pump 51 via a check valve 58. This relief valve 59 can be configured in the same way as a conventional relief valve, and is configured to open when the oil pressure in the output oil passage 57 is above a predetermined pressure, thereby discharging oil from the output oil passage 57 to the oil tank 52 and reducing the oil pressure in the output oil passage 57 to a predetermined pressure, and conversely, to close when the pressure in the output oil passage 57 is below a predetermined pressure, thereby increasing the oil pressure in the output oil passage 57.

[0083] A directional control valve 61 is connected to the output oil passage 57 via a flow control valve 60. This directional control valve 61 is a pilot-operated solenoid valve and includes an input port 62 communicating with the output oil passage 57, a first output port 63, a second output port 64, and a drain port 65 communicating with the oil tank 52. The directional control valve 61 also includes a spool 66 that switches between a pushed-down position in which the input port 62 and the first output port 63 are in communication and the second output port 64 is in communication and the drain port 65 is in communication, a brake position in which each of the ports 62, 63, 64, and 65 is closed, and an pulled-up position in which the input port 62 and the second output port 64 are in communication and the first output port 63 is in communication and the drain port 65 is in communication.

[0084] To move the spool 66, a solenoid 67a is provided that pushes the spool 66 to the downward position by pilot pressure supplied by electromagnetic force, and a solenoid 67b is provided that pushes the spool 66 to the upward position by pilot pressure supplied by electromagnetic force. In addition, when the solenoids 67a and 67b are not energized, spool springs 68a and 68b are provided that press the spool 66 from both sides to move the spool 66 to the neutral position (brake position).

[0085] Furthermore, a cylinder 49 is connected to the first output port 63 and the second output port 64. This cylinder 49 is a double-acting hydraulic cylinder, and is provided with a piston 69 connected to the slide 5. The first output port 63 is connected to the hydraulic chamber 70 on the cap side of the cylinder 49. The second output port 64 is connected to the hydraulic chamber 71 on the rod side of the cylinder 49.

[0086] Therefore, by energizing the solenoid 67a so that a pressing force greater than the spring force of the spool spring 68b acts on the spool 66, the pilot pressure causes the spool 66 to move to the down position. As a result, hydraulic pressure is supplied from the hydraulic pump 51 to the hydraulic chamber 70 on the cap side of the cylinder 49, and oil is discharged from the hydraulic chamber 71 on the rod side of the cylinder 49 to the oil tank 52, thereby acting as a load to push the piston 69 out. Conversely, by energizing the solenoid 67b so that a pressing force greater than the spring force of the spool spring 68a acts on the spool 66, the pilot pressure causes the spool 66 to be pressed and move to the up position. As a result, hydraulic pressure is supplied from the hydraulic pump 51 to the hydraulic chamber 71 on the rod side of the cylinder 49, and oil is discharged from the hydraulic chamber 70 on the cap side of the cylinder 49 to the oil tank 52, thereby acting as a load to pull the piston 69 in.

[0087] Furthermore, by stopping the power supply to each solenoid 67a and 67b, the spool 66 moves to the brake position (neutral position) and is maintained in that brake position. In other words, by selectively switching which solenoid 67a (67b) is energized, or by stopping the supply of current to it, the position of the spool 66 can be controlled to either the pushed-down position, the brake position, or the pushed-up position.

[0088] A rod 72 integrated with the piston 69 is connected to a slide 5. Therefore, as described above, by controlling the current supplied to each solenoid 67a and 67b, the hydraulic load acting on the piston 69 acts on the slide 5, causing the slide 5 to reciprocate. The cylinders 49 and 50, including the piston 69, correspond to the "load supply unit" in the embodiment of the present invention.

[0089] Furthermore, the basic configuration, such as the connection of the upper die 17 to the slide 5, can be configured in the same way as the example shown in Figure 1. In the case of a hydraulic press, a sensor is provided to detect the height of the slide 5, and the height detected by the sensor is displayed.

[0090] In the hydraulic press configured as described above, similar to a mechanical press, the slide 5 can be moved by operating the control unit 37 to energize the solenoid 67a (67b). Specifically, by setting the normal inching mode, the slide 5 can be moved while the control unit 37 is being operated. Furthermore, when the pulse output mode is set and the control unit 37 is being operated, the slide 5 can be moved intermittently by controlling whether or not the solenoid 67a or solenoid 67b is energized so that the spool 66 moves back and forth between the pushed-down position, the pushed-up position and the brake position (i.e., the stop position). Therefore, similar to the mechanical press described above, the position of the slide 5 can be easily adjusted to the bottom dead center (target position) by operating the control unit 37 while checking the position of the slide 5 displayed on the display unit until the slide 5 moves to the bottom dead center (target position). As a result, the time required to attach the upper die 17 and the lower die 21 can be shortened, and work efficiency can be improved.

[0091] Furthermore, the control device for a press machine in the embodiment of the present invention is not limited to new press machines, but may also be used for existing press machines, for example, by implementing a pulse output mode setting unit 44b in the PLC 42 and providing an output mode switching operation unit 38 in the controller 36 during press machine maintenance. [Explanation of symbols]

[0092] 1 Press machine 2.54 motor 3 Flywheel 4. Clutch mechanism 4a Cylinder for clutch 5 slides 6 cabinets 6a Bed section 7 Output shaft 8. Drive-side pulley 9 belts 10 Drive shafts 11 Pinion Gear 12 Crank Axle 12a Crankpin 13 Main gear 14. Crank angle sensor 15 Brake mechanism 15a Brake cylinder 16 Connecting Rods 17 Upper mold 19 Slide Gib 20 bolster 21 Lower mold 22 Storage Unit 23. Air pressure source 24 Regulator Valve 25 Pressure switch 26 Lubricators 27 Double-acting solenoid valve 28 channels 29 Pressure gauge 30,66 spool 31,62 Input Ports 32,65 Drain port 33, 63, 64 output ports 34, 67a, 67b Solenoids 35, 68a, 68b Spool spring 36 Controllers 37 Control section 38 Output mode switching operation section 39 Emergency Stop Button 40 Operating mode switching control unit 42 Programmable Logic Controllers (PLCs) 43 Operating mode determination unit 44. Inch Mode Setting Section 44a Normal increment mode setting section 44b Pulse output mode setting section 45 Simultaneous Operation Judgment Unit 46 Operating Condition Determination Unit 47. Pulse width setting section 48 Output section 49 Main Cylinder 50 Side Cylinder 51 Hydraulic pump 52 Oil Tank 53 Valve Unit 55 Oil road 56 Strainer 57 Output oil passage 58 Check valve 59 Relief valve 60 Flow control valve 61 Directional control valve 69 Pistons 70,71 Hydraulic chamber 72 rods

Claims

1. A control device for a press machine comprising: a slide that performs press working by reciprocating motion; a load supply unit that applies a load to the slide according to fluid pressure; an operation unit that outputs a signal to operate the slide when operated by an operator; and a control valve that can switch between a supply position that supplies fluid pressure from a pressure source to the load supply unit based on a signal from the operation unit, and a shut-off position that shuts off the supply of fluid pressure from the pressure source to the load supply unit, wherein The system includes a controller that controls the aforementioned control valve, The aforementioned controller, The system is configured to allow selection between a normal inching mode, in which, while the operating unit is being operated by the operator, a command signal is output to the control valve instructing the supply of fluid pressure to the load supply unit via the control valve in response to a signal output from the operating unit, and when the operator's operation of the operating unit is released, a command signal is output to the control valve instructing the shutoff of the fluid pressure to the load supply unit via the control valve; and a pulse output mode, in which, while the operating unit is being operated by the operator, a pulse-like command signal is output to the control valve in response to a signal output from the operating unit, repeatedly supplying and shutting off fluid pressure to the load supply unit via the control valve. A control device for a press machine characterized by the following features.

2. A control device for a press machine according to claim 1, The aforementioned controller, The system further includes an inching mode setting unit for setting an inching mode to adjust the slide to a predetermined position, The pulse output mode can be set on the condition that the inching mode is set by the inching mode setting unit. A control device for a press machine characterized by the following features.

3. A control device for a press machine according to claim 1, The system further includes an output mode switching operation unit for switching between the normal inching mode and the pulse output mode. A control device for a press machine characterized by the following features.

4. A control device for a press machine according to claim 1, The aforementioned controller, In the pulse output mode, the system further includes a pulse width setting unit that sets the interval between the operating time for supplying fluid pressure to the load supply unit and the interruption time for interrupting the supply of fluid pressure to the load supply unit. A control device for a press machine characterized by the following features.

5. A control device for a press machine according to claim 1, A motor as a driving force source, An inertial body rotated by the aforementioned motor, A crankshaft connected to the slide and rotating to cause the slide to reciprocate, The clutch mechanism includes a clutch mechanism that selectively switches between an engaged state, which transmits the power of the inertial body to the crankshaft, and a released state, which interrupts the transmission of power between the inertial body and the crankshaft. The clutch mechanism comprises a cylinder to which fluid is supplied, and a control valve that supplies fluid pressure to the cylinder when energized. The load supply unit includes the clutch mechanism. A control device for a press machine characterized by the following features.

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