JP2006150422A - Screw driven type hydraulic press device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To realize a rapid traverse in which controllability and the positional precision of a transmission driving mechanism are satisfactory and the loss of energy is reduced even in a hybrid screw driven type hydraulic press device in which the respective strong points of an electrically driven type and a hydraulically driven type are made the most of. <P>SOLUTION: A slide 12 coupled to the edge part of an output rod 3c in a sleeve cylinder 3 is moved at a high speed to a working position by a rapid traverse driven part B having a ball screw unit 15, a timing belt apparatus 16 and an AC servomotor 17 for a rapid traverse as hydraulic pressure control is performed by prefill valves 6, 7, and, at the working position, an input rod 2c in a master cylinder 2 is driven by a pressurization driving part A, and mold clamping working and press working are allowed to perform. After the completion of the working, the slide 12 is elevated to a standard position by the pressure driving part A, and further, the slide 12 is retreated to an upper dead point by the rapid traverse driving part B. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a highly energy-efficient screw-driven press device suitable as an actuator for a press machine used, for example, in material processing and molding.

  Conventionally, press machines have been used for shearing, bending, drawing, forging of metal materials, molding of rubber tires, molding of plastic bathtubs, and the like. As a drive system of a press machine, a hydraulic drive type and an electric drive type are generally used. The hydraulic drive type is easy to output easily, but is inferior in heat loss, running cost, accuracy, drive efficiency, etc. of devices such as a hydraulic pump and a servo valve. The electric drive type has good controllability and position accuracy of the transmission drive mechanism, and there is little energy loss. However, when high output is required, the size and cost of the motor and mechanical parts are bulky to improve durability. However, there is a disadvantage that the apparatus becomes expensive and the mechanism becomes complicated.

  Thus, the hydraulic drive type and the electric drive type have their merits and demerits, and an EHL (Electro Hydraulic Linear) drive system has been developed to compensate for this. The EHL drive system is a hybrid drive system that takes advantage of both the electric drive type and the hydraulic drive type, and uses a motor as a power source and a hydraulic cylinder as an amplifying device. As an EHL driving method, there is one proposed by the present inventor (see Patent Document 1). This includes a master cylinder driven by a motor and a ball screw, and a slave cylinder that operates with hydraulic oil from the master cylinder to process a workpiece. Since the flow rate and diversion from the slave cylinder to the master cylinder are set the same, unlike the conventional hydraulic drive type, hydraulic oil circulates in the closed circuit on the cylinder head side and rod side. It is possible to prevent deterioration of hydraulic oil and temperature change due to reduction of heat and heat loss of servo valves, and there is an advantage that a hydraulic press with high energy efficiency can be realized.

In addition, in the above-mentioned Patent Document 1, the inventor of the present application is configured such that the master cylinder is composed of the first and second master cylinders, and when the stroke length of the slave cylinder is long, the slave cylinder is driven at a high speed by the second master cylinder. A hydraulic press apparatus has also been proposed in which a piston is sent to a working point and pressurizing is performed using hydraulic oil from a first master cylinder during press work. This device has the advantage that the slide can be fast-forwarded to the working point.
JP 2002-295624 A

  However, in the above-described hydraulic press device capable of rapid feed, the slave cylinder is driven at a high speed by the second master cylinder to feed the piston to the working point, and during the press work, pressurization is performed using hydraulic oil from the first master cylinder. Therefore, there is a problem that controllability and position accuracy of the transmission drive mechanism are poor and energy loss is large with respect to rapid traverse.

  An object of the present invention is to solve such a conventional problem, and to provide a screw-driven hydraulic press device capable of rapid feed, which has good controllability and positional accuracy of a transmission drive mechanism, and has low energy loss. To do.

  In order to solve the above problems, the screw drive hydraulic press device of the present invention has a piston housed in a cylinder tube filled with hydraulic oil, and an input rod extending from one end of the piston is projected from one end of the cylinder tube. The first cylinder is paired with the first cylinder, and another piston is accommodated in another cylinder tube that fills the hydraulic oil, and an output rod extending from one end of the other piston is extended from one end of the other cylinder tube. The projecting second cylinder, a first pipe connecting one end of the cylinder tube of the first cylinder and one end of the cylinder tube of the second cylinder, and the other end of the cylinder tube of the first cylinder And a second pipe connecting the other end of the cylinder tube of the second cylinder, and a first prefill provided in the first pipe A second prefill valve provided in the second pipe, a ball screw unit for linearly driving the input rod of the first cylinder, and a servo motor for rotating the ball screw of the ball screw unit; A pressure drive unit including: a ball screw unit for linearly driving a slide coupled to an end of the output rod of the second cylinder; and a servo motor for rotating the ball screw of the ball screw unit. And a cross-sectional area of the input rod from a cross-sectional area of the cylinder tube of the first cylinder and a cross-sectional area of the output rod from a cross-sectional area of the cylinder tube of the second cylinder. The ratio between the area and the cross-sectional area of the cylinder tube of the first cylinder and the cross-sectional area of the cylinder tube of the second cylinder , Characterized by being in the same ratio.

  In the screw-driven hydraulic press apparatus configured as described above, when the servo motor of the fast-forward drive unit is rotated forward, the rotational force is transmitted to the ball screw, and the slide is advanced at a high speed. At this time, the first prefill valve is opened by the electromagnetic valve, and the hydraulic oil in the second cylinder is pushed by the piston and flows out from one end side of the cylinder tube, and the first prefill valve opened from the first pipe is opened. Flows out into the tank. At the same time, hydraulic oil is supplied from the tank to the other end of the cylinder tube of the second cylinder via the second prefill valve. When the slide stops at a predetermined forward position, the first prefill valve is closed and the servomotor of the fast-forward drive unit is in a free state. Next, the servo motor of the pressure drive unit is rotated forward, the rotational force is transmitted to the ball screw, the input rod of the first cylinder is advanced from one end side to the other end side, and the hydraulic oil in the first cylinder is Is pushed by the piston and flows out from the other end of the cylinder tube, flows into the other end of the cylinder tube of the second cylinder through the second pipe, and pushes the piston to advance the output rod in the pressurizing direction. At the same time, the hydraulic oil in the second cylinder flows out from the other end side of the cylinder tube and flows into the other end side of the cylinder tube of the first cylinder through the first pipe. When the output rod reaches a predetermined forward position, the servo motor of the pressure drive unit stops rotating and enters a free state. Since the input rod of the first cylinder presses the piston with the thrust corresponding to the torque of the servo motor to pressurize the hydraulic oil, the thrust of the output rod, that is, the output of the second cylinder, follows the Pascal principle and the cylinder tube of the first cylinder is disconnected. Thrust is generated according to the ratio between the area and the cross-sectional area of the cylinder tube of the second cylinder. For example, if the ratio is 10, the thrust of the second cylinder is 10 times that of the first cylinder. After pressurization by the second cylinder, when the servo motor of the fast-forward drive unit is reversely rotated, the rotational force is transmitted to the ball screw, the slide is moved backward, and the hydraulic oil in the second cylinder is pushed by the piston accordingly. From the other end of the cylinder tube, it flows out into the tank through the second piping through the second prefill valve opened by the electromagnetic valve, and at the one end side of the cylinder tube of the second cylinder through the first prefill valve. The hydraulic oil is supplied from the tank.

  The screw drive type hydraulic press device of the present invention includes a first movement amount detecting means for detecting a movement amount of the input rod of the first cylinder and a second movement for detecting the movement amount of the output rod of the second cylinder. An amount detection means, and a control means for stopping the input rod and the output rod at a predetermined forward stop position and a reverse stop position based on signals from the first and second movement amount detection means, With this configuration, the slide coupled to the protruding end portion of the output rod can be moved to the predetermined forward stop position and the reverse stop position, and the input rod can be moved by a predetermined amount.

  Further, the screw drive type hydraulic press device according to the present invention is characterized in that the control means can arbitrarily set the forward stop position. With this configuration, for example, a punch attached to a slide and The space between the die on the bed can be arbitrarily set according to the size of the workpiece and the work content.

  Further, the screw drive type hydraulic press device of the present invention is characterized in that the control means arbitrarily sets the forward stop position based on a signal from an origin position sensor. A reference point and a forward stop position for a plurality of workpieces having different sizes can be set with a simple configuration.

  According to the present invention, the slide coupled to the end of the output rod of the second cylinder is moved at high speed to the working position by the fast-forward drive unit having the ball screw and the servo motor while adjusting the hydraulic pressure by the prefill valve. In this position, the input rod of the first cylinder is driven by the pressurization drive unit to perform the clamping and pressing operations. Therefore, a hybrid screw-driven hydraulic press device that takes advantage of the advantages of both electric drive and hydraulic drive. In this case, it is possible to realize a screw-driven hydraulic press apparatus that can be fast-forwarded by electric drive, has good controllability and position accuracy of the transmission drive mechanism, and has little energy loss.

  Embodiments of a screw drive type hydraulic press device of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic diagram showing a system configuration of a screw drive type hydraulic press apparatus (hereinafter simply referred to as a hydraulic press apparatus) of the present embodiment.

  The hydraulic press device 1 according to the present embodiment is roughly divided into a first hydraulic cylinder consisting of a master cylinder 2 as a first cylinder and a slave cylinder 3 as a second cylinder, and a first cylinder that connects each end of both cylinders 2 and 3. 1 piping 4 and 2 piping 5, the 1st prefill valve 6 provided in the middle of the 1st piping 4, the 2nd prefill valve 7 provided in the middle of the 2nd piping 5, and the input rod of master cylinder 2 A ball screw unit 8 for reciprocating the motor, a pressurizing AC servomotor 10 for driving the ball screw unit 8 via a timing belt device 9, an upper frame 11 for supporting the upper end of the slave cylinder 3, and a slave cylinder 3 is erected at the four corners between the slide 12 fixed to the lower end of the output rod 3 and the upper frame 11 and the bed 13. Guide post 14 that slides and guides the movement of the slide 12, a ball screw unit 15 that is provided at two positions on the left and right of the upper surface of the slide 12 to reciprocate the slide 12, and the ball screw unit 15 via the timing belt device 16. And a fast-feed AC servomotor 17 for driving. The pressurizing AC servomotor 10, the timing belt device 9, the ball screw unit 8, and the master cylinder 2 constitute a pressurizing drive unit A, and the fast-feeding AC servomotor 17, the timing belt device 16, and the ball screw unit 15 fast-forward. The drive part B is comprised.

  More specifically, the master cylinder 2 includes a cylinder tube 2a that fills hydraulic fluid, a piston 2b that is slidably accommodated in the cylinder tube 2a, and extends from one end of the piston 2b and protrudes from one end of the cylinder tube 2a. A small cross-sectional chamber 2d having a cross-sectional area obtained by subtracting the cross-sectional area of the input rod 2c from the cross-sectional area of the cylinder tube 2a on one end side, and the cross-sectional area of the cylinder tube 2a on the other end side. The large cross-sectional chamber 2e having the piston 2b is formed. The slave cylinder 3 includes a cylinder tube 3a that fills hydraulic oil, a piston 3b that is slidably accommodated in the cylinder tube 3a, and an output rod 3c that extends from one end of the piston 3b and projects from one end of the cylinder tube 3a. The small cross-sectional chamber 3d having a cross-sectional area obtained by subtracting the cross-sectional area of the output rod 3c from the cross-sectional area of the cylinder tube 3a is provided on one end side, and the large cross-sectional chamber 3e having a cross-sectional area of the cylinder tube 3a is provided on the other end side. It is formed across 3b. The area ratio of the area obtained by subtracting the cross-sectional area of the input rod 2c from the cross-sectional area of the cylinder tube 2a of the master cylinder 2 and the area obtained by subtracting the cross-sectional area of the output rod 3c from the cross-sectional area of the cylinder tube 3a of the slave cylinder 3 is 1 : N (for example, N = 10), and the area ratio of the cross-sectional area of the cylinder tube 2a of the master cylinder 2 to the cross-sectional area of the cylinder tube 3a of the slave cylinder 3 is 1: N (N = 10) as described above. is there.

  The first pipe 4 connects the small cross-sectional chamber 2d on one end side of the master cylinder 2 and the small cross-sectional chamber 3d on one end side of the slave cylinder 3, and communicates both the small cross-sectional chambers 2d and 3d with hydraulic oil. The second pipe 5 connects the large cross-sectional chamber 2e on the other end side of the master cylinder 2 and the large cross-sectional chamber 3e on the other end side of the slave cylinder 3, and communicates both large cross-sectional chambers 2e and 3e with hydraulic oil. . A cylinder side port of the first prefill valve 6 is connected to the first pipe 4, and a cylinder side port of the second prefill valve 7 is connected to the second pipe 5. The tank-side ports of the pre-fill valves 6 and 7 are led to the same tank 20 by pipes 6a and 7a, respectively, and the pipes 6b and 7b are connected to the pilot ports so that pilot pressure is supplied from the solenoid valves 21a and 21b. It is like that.

  The ball screw unit 8 in the pressure driving unit A includes a nut 8b fixed to the tip of the hollow input shaft 2c of the master cylinder 2 and a ball screw 8a screwed to the nut 8b. The base end portion of the ball screw 8a is fixed to the driven pulley 9b of the timing belt device 9, and the timing belt 9c is stretched between the driven pulley 9b and the driving pulley 9a. The driving pulley 9a is an AC servomotor for pressurization. It is fixed to 10 rotation shafts.

  The ball screw unit 15 in the fast-forward drive unit B is fixed to the upper end portion of a sleeve 15c fixed to the slide 12 and a ball screw 15a supported on the upper frame 11 so as not to be movable in the axial direction and rotatable. And a nut 15b to be screwed together. The driven pulley 16b of the timing belt device 16 is fixed to the lower part of the upper frame 11 of the ball screw 15a, the timing belt 16c is stretched between the driven pulley 16b and the driving pulley 16a, and the driving pulley 16a is It is fixed to the rotating shaft of the fast-feed AC servomotor 17.

  The upper end portion of the cylinder tube 3 a of the slave cylinder 3 is fixed to the lower surface of the upper frame 11, and the slider 12 is fixed to the lower end portion of the output shaft 3 c of the slave cylinder 3. The slider 12 is slidably guided by guide posts 14 erected at the four corners between the upper frame 11 and the bed 13, and is attached to the punch 19 attached to the lower surface of the slider 12 and the upper surface of the bed 13. Processing is performed on the workpiece inserted between the die 19.

  The control system controls the first electromagnetic valve 21a and the second electromagnetic valve 21b that apply pilot pressure to the first prefill valve 6 and the second prefill valve 7, respectively, and outputs a pulse train to the pressurizing AC servomotor 10. The controller 22 receives a pulse signal indicating the amount of rotation from the encoder 10a integrated with the pressurizing AC servomotor 10 and outputs a pulse train to the fast-feed AC servomotor 17 to drive it. A controller 24 that receives a pulse signal indicating a rotation amount from an encoder 17a integrated with the servo motor 17 and receives a signal from an origin position sensor 23 that is a photocoupler that detects the origin position of the slide 12 in the fast-forward drive unit B; A personal computer 2 connected to the controllers 22 and 24 Constitute a control means and.

  Next, the operation of the hydraulic press device configured as described above will be described. In the personal computer 25, various data about the work process for each workpiece are input in advance. The origin position sensor 23 is installed at the maximum reference position Pmax which is the position of the slide 12 when processing the workpiece having the maximum height. In the present embodiment, the maximum reference position Pmax becomes the origin position Op. ing. The controller 24 cumulatively adds the number of pulses output from the encoder 17a from the maximum reference position Pmax to detect the top dead center of the slide 12, and the controller 24 outputs a stop signal to the fast-forward AC servomotor 17 to stop it. Let On the other hand, when descending from the top dead center, when the controller 24 counts the number of pulses from the encoder 17a and detects that it has reached the maximum reference position Pmax, that is, the origin position Op, a stop signal is sent to the fast-feed AC servo motor 17. To stop it. When processing the workpiece or flat plate material having the minimum height, the number of pulses from the origin position Op to the minimum reference position Pmin is measured, and the position corresponding to the pulse number is set as the minimum reference position Pmin. Therefore, the position from the minimum reference position Pmin to the top dead center is obtained by adding the number of pulses from the origin position Op to the minimum reference position min to the number of pulses from the origin position Op to the top dead center. The same applies when another reference position is set between the maximum reference position Pmax and the minimum reference position Pmin.

  When a workpiece to be processed is selected from a list displayed on the personal computer 25, the data is read into the controllers 22 and 24. Before the press device is started, the slave cylinder 3 is located at the top dead center position as shown in FIG. When the press device is turned on and the controllers 22 and 24 and the personal computer 25 are activated, the pressurizing AC servo motor 10 is brought into a free state by a command from the controller 22, and the first electromagnetic valve 21a is connected to the first prefill valve 6. Is supplied with pilot pressure, and the first prefill valve 6 is opened. At the same time, the fast-feed AC servo motor 17 rotates forward in response to a command from the controller 24, and the ball screw 15 a rotates via the timing belt device 16 to fast-forward the slide 12.

  This will be described below with reference to the timing chart of FIG. In the high-speed mold closing process (1), the nut 15b is lowered along the ball screw 15a by the rotation of the ball screw 15a, so that the slide 12 is lowered via the sleeve 15c. When the slide 12 descends, the output rod 3c of the slave cylinder 3 fixed to the slide 12 is pushed down, and the piston 3b pushes the hydraulic oil in the small cross-section chamber 3d to flow out to the first pipe 4. At this time, since the first prefill valve 6 is opened, the hydraulic oil flowing through the first pipe 4 is guided from the first prefill valve 6 into the tank 20. When the piston 3b is pushed down, the hydraulic oil in the tank 20 flows from the second prefill valve 7 through the second pipe 5 into the large cross-section chamber 3e. When the slider 12 descends and reaches, for example, the maximum reference position Pmax, and this is detected by the origin position sensor 23, the controller 24 stops the rapid feed AC servo motor 17 to be in a free state, and receives a stop signal from the personal computer 25. The controller 22 controls the first electromagnetic valve 21a to close the first prefill valve 6 and enters the next high-pressure type closing process (2).

  In the high pressure type closing process (2), when the servo motor 10 rotates forward in accordance with the pressurization command from the controller 22, the ball screw 8a rotates through the timing belt device 9, and the input rod of the master cylinder 2 through the nut 8b. Increase 2c. At this time, the hydraulic oil in the large cross-section chamber 2e of the master cylinder 2 is pushed out by the piston 2b, flows into the large cross-section chamber 3e of the slave cylinder 3 through the second pipe 5, and pushes the piston 3b to push the output rod 3c. Lower. At the same time, the hydraulic oil in the small cross section chamber 3d of the slave cylinder 3 is pushed by the piston 3b and flows into the small cross section chamber 2d of the master cylinder 2 through the first pipe 4.

  When the controller 22 measuring the number of pulses from the encoder 10a of the pressurizing AC servomotor 10 detects that the output rod 3c has reached the working position from the measured number of pulses in the pressurizing process (3). Then, a stop command is sent to the pressurizing AC servo motor 10 to stop it for a predetermined time. As a result, the slave cylinder 3 is also stopped, and the output rod 3c generates a pressure corresponding to the specified torque value to process the workpiece. If this hydraulic press device is used as a pressurizing actuator of a press machine, a workpiece is processed between a punch 18 attached to the output rod 3c and a die 19 placed opposite thereto. Since the input rod 2c of the master cylinder 2 presses the piston 2b with a thrust force corresponding to the torque of the pressurizing AC servo motor 10 to pressurize the hydraulic oil, the output of the output rod 3c of the slave cylinder 3 follows the Pascal principle. Thrust is generated in accordance with the ratio of the cross-sectional area of the cylinder tube 2a of the second cylinder and the cross-sectional area of the cylinder tube 3a of the slave cylinder 3. For example, if the ratio is 10, the thrust of the slave cylinder 3 is 10 times that of the master cylinder 2.

  In the pressurization release process (4), when a return command is issued from the controller 22 to the pressurizing AC servomotor 10 after a predetermined time has elapsed, the pressurizing AC servomotor 10 rotates reversely by a predetermined number of pulses, and the master cylinder 2 The input rod 2c descends, and the hydraulic oil in the small cross-sectional chamber 2d of the master cylinder 2 flows into the small cross-sectional chamber 3d of the slave cylinder 3 through the first pipe 4 to raise the output rod 3c of the slave cylinder 3 and Part of the hydraulic oil in the large cross-section chamber 3e of the cylinder 3 returns to the large cross-section chamber 2e of the master cylinder 2 through the second pipe 5. When the pressurization AC servomotor 10 reverses the set number of pulses and finishes releasing the pressurization, the controller 22 stops the AC servomotor 10 to be in a free state and controls the second electromagnetic valve 21b. The second prefill valve 7 is closed. On the other hand, the personal computer 25 that has received the pressurization release end signal from the controller 22 reverses the fast-feed AC servomotor 17 via the controller 24 to perform the high-speed mold opening process (5).

  In the high-speed mold opening process (5), the fast-feed AC servomotor 17 is reversely rotated by a command from the controller 24, and the ball screw 15a is rotated via the timing belt device 16. By this rotation, the nut 15b rises along the ball screw 15a, and the slide 12 rises through the sleeve 15c. When the slide 12 rises, the output rod 3c of the slave cylinder 3 fixed to the slide 12 is pushed up, and the piston 3b pushes the hydraulic oil in the large cross section chamber 3e to flow out through the second pipe 5. At this time, since the second prefill valve 7 is opened, the hydraulic oil flowing through the second pipe 5 is guided from the second prefill valve 7 into the tank 20. When the piston 3b is pushed up, the hydraulic oil in the tank 20 flows from the first prefill valve 6 through the first pipe 4 into the small cross-section chamber 3d. When the fast-feed AC servomotor 17 receives a signal from the origin position sensor 23 and rotates by a predetermined number of pulses from the origin position Op, the slide 12 reaches top dead center, and the controller 24 rotates the fast-feed AC servomotor 17. The PC 25 is stopped and brought into a free state, and a high-speed mold opening end signal is sent to the personal computer 25. Upon receipt of the signal, the personal computer 25 notifies the controller 22 that the high-speed mold opening has been completed. And the second prefill valve 7 is closed to complete the one-shot stroke.

  When processing another workpiece, when the workpiece is selected by the personal computer 25, for example, when the workpiece has a minimum height or is a flat plate material, the data is sent to each controller 22, 24. Is set. The data of the minimum reference position Pmin is set by the number of pulses in the minus direction from the maximum reference position Pmax which is the origin position Op. When the press apparatus is activated, the controller 24 rotates the fast-forward AC servo motor 17 in the normal direction, lowers the slide 12 while measuring the number of pulses from the encoder 17a, measures the predetermined number of pulses, and the slide 12 is at the minimum reference position. When it is detected that Pmin has been reached, the fast-feed AC servomotor 17 is stopped and put into a free state, and the controller 22 rotates the pressurizing AC servomotor 10 in the forward direction to drive the piston 2b by the set number of pulses, The above-described high-pressure type closing process (2) and pressure processing process (3) are performed. After pressurization, the controller 22 performs the pressurization release process (4) by reversing the pressurization AC servomotor 10 by the set number of pulses, and the personal computer 25 receiving the pressurization release end signal receives the pressurization release end signal. The fast-feed AC servomotor 17 is reversely rotated through the high-speed mold opening process (5). When the fast-feed AC servomotor 17 receives a signal from the origin position sensor 23 and rotates a predetermined number of times from the origin position Op, the slide 12 reaches top dead center and stops by a stop signal from the controller 24.

  Thus, according to the present embodiment, the ball screw unit 15 and the timing belt device are adjusted while adjusting the hydraulic pressure of the slide 12 coupled to the end of the output rod 3c of the slave cylinder 3 by the prefill valves 6 and 7. 16 and a fast-feed drive unit B having a fast-feed AC servomotor 17 are moved to a work position at high speed, and the input rod 2c of the master cylinder 2 is driven by the pressurization drive unit A at the work position to perform a clamping operation and a press work. Therefore, even in hybrid screw drive hydraulic presses that take advantage of both electric drive type and hydraulic drive type, fast feed is possible by electric drive, controllability and position accuracy of transmission drive mechanism are good, energy loss There is an effect that there is little. Further, since the fast-feed AC servomotor 17 requires less torque than the pressurizing AC servomotor 10, the component cost can be reduced.

  In the above embodiment, the rotation of the AC servo motor is transmitted to the ball screw via the timing belt device. However, the ball screw may be directly driven by the AC servo motor provided with a speed reduction mechanism. Moreover, although the encoder integrated with the AC servo motor is used as the movement amount detecting means, a linear scale or the like can also be used. Further, although the photo sensor is used as the origin position sensor, other sensors may be used. In addition to the servo control function, a controller having an I / O control such as an electromagnetic valve and a sensor and a communication function with a personal computer is used. However, other types of controllers may be used.

It is the schematic which shows the structure of the screw drive type hydraulic press apparatus in embodiment of this invention. It is a timing diagram which shows the press process in embodiment of this invention.

Explanation of symbols

1 Screw-driven hydraulic press 2 Master cylinder (first cylinder)
2a Cylinder tube 2b Piston 2c Input rod 3 Slave cylinder (2nd cylinder)
3a Cylinder tube 3b Piston 3c Output rod 4 1st piping 5 2nd piping 6 1st prefill valve 7 2nd prefill valve 8 Ball screw unit 8a Ball screw 8b Nut 9 Timing belt device 9a Drive pulley 9b Driven pulley 9c Timing belt 10 Addition AC servomotor for pressure 10a Encoder (first movement detection means)
11 Upper Frame 12 Slide 13 Bed 14 Guide Post 15 Ball Screw Unit 15a Ball Screw 15b Nut 16 Timing Belt Device 16a Drive Pulley 16b Driven Pulley 16c Timing Belt 17 Fast-feed AC Servo Motor 17a Encoder (Second Movement Amount Detection Means)
18 Punch 19 Die 20 Tank 21a First Electromagnetic Valve 21b Second Electromagnetic Valve 22 Controller 23 Origin Position Sensor 24 Controller 25 Personal Computer

Claims (4)

A first cylinder in which a piston is housed in a cylinder tube filled with hydraulic oil, and an input rod extending from one end of the piston is projected from one end of the cylinder tube;
A second cylinder that forms a pair with the first cylinder, houses a piston in a cylinder tube that fills the hydraulic oil, and projects an output rod extending from one end of the piston from one end of the cylinder tube;
A first pipe connecting one end of the cylinder tube of the first cylinder and one end of the cylinder tube of the second cylinder;
A second pipe connecting the other end of the cylinder tube of the first cylinder and the other end of the cylinder tube of the second cylinder;
A first prefill valve provided in the first pipe;
A second prefill valve provided in the second pipe;
A pressure drive unit having a ball screw unit for linearly driving the input rod of the first cylinder, and a servo motor for rotating the ball screw of the ball screw unit;
A ball screw unit for linearly driving a slide coupled to an end of an output rod of the second cylinder, and a fast-forward drive unit having a servo motor for rotating the ball screw of the ball screw unit;
The ratio of the area obtained by subtracting the cross-sectional area of the input rod from the cross-sectional area of the cylinder tube of the first cylinder to the area obtained by subtracting the cross-sectional area of the output rod from the cross-sectional area of the cylinder tube of the second cylinder; A screw-driven hydraulic press apparatus characterized in that the ratio of the cross-sectional area of the cylinder tube of one cylinder and the cross-sectional area of the cylinder tube of the second cylinder is the same.   First movement amount detection means for detecting the movement amount of the input rod of the first cylinder; second movement amount detection means for detecting the movement amount of the output rod of the second cylinder; and the first and second movement amounts. The screw drive type hydraulic press apparatus according to claim 1, further comprising a control means for stopping the input rod and the output rod at a predetermined forward stop position and a reverse stop position based on a signal from the detection means.   The screw drive type hydraulic press device according to claim 2, wherein the control means can arbitrarily set the forward stop position.   The screw drive type hydraulic press device according to claim 3, wherein the control means arbitrarily sets the forward stop position based on a signal from an origin position sensor.

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