Hydraulic circuit control device and molding machine

Abstract

A hydraulic circuit control device is provided with a drive motor, a drive-side cylinder including a drive-side liquid chamber and a drive-side piston that is moved by the drive motor, a driven-side cylinder including a driven-side piston that is moved by the drive motor, and a liquid path volume adjustment mechanism. The driven-side cylinder includes a driven-side liquid chamber, a liquid path connecting the driven-side liquid chamber and the driving-side liquid chamber, and a driven-side piston that moves by moving the driving-side piston and increasing or decreasing the amount of the working liquid in the driven-side liquid chamber via the liquid path. The liquid path volume adjusting mechanism increases or decreases the volume of the liquid path according to the increase or decrease of the volume of the working liquid.

Description

Technical Field

[0001] The present invention relates to a hydraulic circuit control device and a molding machine, and more particularly to a hydraulic circuit control device and a molding machine including a driving side cylinder and a driven side cylinder driven by the driving side cylinder. Background Art

[0002] Conventionally, there is known a hydraulic cylinder device including a driving cylinder and a driven cylinder driven by the driving cylinder. For example, Japanese Patent Application Laid-Open No. 2000-356202 discloses such a hydraulic cylinder device.

[0003] In the above-mentioned Japanese Patent Publication No. 2000-356202, a hydraulic cylinder device is disclosed, which includes a driving side cylinder and a control cylinder (driven side cylinder) driven by the driving side cylinder. The oil chamber in the driving side cylinder and the oil chamber in the control cylinder are connected via a hydraulic hose (fluid path). The hydraulic cylinder device is configured such that as the piston of the driving side cylinder moves forward and backward, the working oil in the oil chamber in the driving side cylinder flows into the oil chamber in the control cylinder via the hydraulic hose, thereby moving the piston of the control cylinder. Patent Literature

[0004] Patent Document 1: Japanese Patent Application Publication No. 2000-356202 Summary of the invention

[0005] However, in the hydraulic cylinder device described in the above-mentioned Japanese Patent Application Laid-Open No. 2000-356202, the volume of the working oil may change due to temperature changes, leakage, etc. In this case, before and after the volume of the working oil changes, the movement amount of the piston of the control cylinder (driven cylinder) relative to the specified movement amount of the piston of the driving cylinder changes (deviates from the set value), so there is a problem that the position accuracy of the piston of the control cylinder (driven cylinder) cannot be ensured.

[0006] The present invention is completed to solve the above problems. One purpose of the present invention is to provide a hydraulic circuit control device and a molding machine that can ensure the position accuracy of the driven side piston of the driven side cylinder even when the volume of the working fluid changes due to temperature changes, leakage, etc. of the working fluid.

[0007] In order to achieve the above-mentioned purpose, the hydraulic circuit control device in the first technical scheme of the present invention includes a driving motor, a driving side cylinder, a driven side cylinder and a fluid path volume adjustment mechanism, the driving side cylinder includes a driving side liquid chamber, and a driving side piston moved by the driving motor, the driven side cylinder includes a driven side liquid chamber, a fluid path connecting the driven side liquid chamber and the driving side liquid chamber, and a driven side piston that moves by the driving side piston and increases or decreases the amount of working fluid in the driven side liquid chamber via the fluid path, and the fluid path volume adjustment mechanism increases or decreases the volume of the fluid path according to the increase or decrease in the volume of the working fluid.

[0008] In the hydraulic circuit control device of the first technical solution of the present invention, as described above, a driving side cylinder, a driven side cylinder and a fluid path volume adjustment mechanism are provided, the driving side cylinder includes a driving side piston, the driven side cylinder includes a driven side piston that moves by the driving side piston and increases or decreases the amount of working fluid in the driven side liquid chamber via the fluid path, and the fluid path volume adjustment mechanism increases or decreases the volume of the fluid path according to the increase or decrease in the volume of the working fluid. Thus, even if the volume of the working fluid increases or decreases due to temperature changes, leakage, etc. of the working fluid inside the fluid path, the driven side liquid chamber, and the driving side liquid chamber, the volume of the fluid path can be increased or decreased according to the increase or decrease in the volume of the working fluid by the fluid path volume adjustment mechanism. Therefore, by increasing or decreasing the volume of the fluid path by the fluid path volume adjustment mechanism, the increase or decrease in the volume of the working fluid can be absorbed, so that the increase or decrease in the volume of the working fluid does not affect the movement amount of the driven side piston. That is, the movement amount of the driven side piston can be corrected so that the movement amount of the driven side piston relative to the specified movement amount of the driving side piston is kept substantially fixed. As a result, even when the volume of the hydraulic fluid varies due to a change in temperature of the hydraulic fluid, leakage, or the like, the position accuracy of the slave-side piston of the slave-side cylinder can be ensured.

[0009] In the hydraulic circuit control device of the above-mentioned first technical solution, preferably, the fluid circuit includes a main fluid circuit portion for causing the working fluid to flow between the driven side fluid chamber and the driving side fluid chamber, and a regulating fluid circuit portion connected to the main fluid circuit portion, and the fluid circuit volume adjustment mechanism includes a volume adjustment motor for moving the inner wall surface of the regulating fluid circuit portion, and is configured to move the inner wall surface so as to increase or decrease the volume of the regulating fluid circuit portion.

[0010] With this structure, the volume of the adjusting fluid path portion can be increased or decreased by moving the inner wall surface of the adjusting fluid path portion by the volume adjusting motor, thereby easily correcting the movement amount of the driven side piston and easily ensuring the position accuracy of the driven side piston of the driven side cylinder.

[0011] In the hydraulic circuit control device of the above-mentioned first technical solution, preferably, in order to adjust the movement amount of the driven side piston relative to the movement of the driving side piston, the fluid circuit volume adjustment mechanism includes a movement adjustment detection unit for detecting at least one of the positions of the driven side piston and the driving side piston, and the state of the working fluid, and is configured to increase or decrease the volume of the fluid circuit based on the detection result of the movement adjustment detection unit.

[0012] If constructed in this way, the movement amount of the driven side piston can be corrected based on the result obtained by detecting at least one of the positions of the driven side piston and the driving side piston and the state of the working fluid using the movement adjustment detection unit. Therefore, the position accuracy of the driven side piston of the driven side cylinder can be more reliably ensured based on the positions of the driven side piston and the driving side piston and the state of the working fluid.

[0013] In this case, preferably, the detection unit for movement adjustment includes at least one of a position detection unit for detecting the positions of the driving side piston and the driven side piston, a liquid temperature detection unit for detecting the temperature of the working fluid, and a hydraulic pressure detection unit for detecting the pressure of the working fluid, and the liquid circuit volume adjustment mechanism is configured to increase or decrease the volume of the liquid circuit based on the detection results of at least one of the position detection unit, the hydraulic pressure detection unit and the liquid temperature detection unit.

[0014] If constructed in this way, it is possible to detect the positions of the driving side piston and the driven side piston that indicate the change in the amount of movement of the driven side piston (the degree of deviation relative to the set value), and any one of the temperature and pressure of the working fluid that affects the change in the amount of movement of the driven side piston, thereby appropriately correcting the amount of movement of the driven side piston according to various conditions.

[0015] In the hydraulic circuit control device of the above-mentioned first technical solution, preferably, the fluid circuit volume adjustment mechanism includes a volume adjustment piston and a volume adjustment ball screw mechanism, the volume adjustment piston is arranged in the fluid circuit, the volume adjustment ball screw mechanism has a volume adjustment ball screw on which the volume adjustment piston is installed, and the volume of the fluid circuit is increased or decreased by moving the volume adjustment piston together with the volume adjustment ball screw.

[0016] According to this structure, the volume adjusting piston can be moved by the volume adjusting ball screw mechanism, so that the volume adjusting piston can be moved with high precision, and the volume of the adjusting fluid path portion can be adjusted with high precision.

[0017] In the hydraulic circuit control device of the above-mentioned first technical solution, preferably, there is further a driving side ball screw mechanism and a driving side ball screw cooling passage, the driving side ball screw mechanism has a driving side ball screw equipped with a driving side piston, and is driven by a driving motor so that the driving side piston moves together with the driving side ball screw, the driving side ball screw cooling passage is arranged inside the driving side ball screw, and a refrigerant for cooling the driving side ball screw flows therein.

[0018] If constructed in this way, the driving side ball screw equipped with the driving side piston can be cooled through the driving side ball screw cooling passage, thereby suppressing the temperature rise of the working fluid caused by the driving side ball screw and the driving side piston, thereby suppressing the volume change of the working fluid itself caused by the temperature rise of the working fluid.

[0019] In the hydraulic circuit control device of the first technical solution, preferably, the fluid circuit volume adjustment mechanism is configured to increase or decrease the volume of the fluid circuit based on at least one of an index value directly indicating the state of increase or decrease in the volume of the working fluid and an index value indirectly indicating the state of increase or decrease in the volume of the working fluid.

[0020] With such a configuration, the volume of the working fluid can be increased or decreased with higher accuracy by taking into account at least one of the index value directly indicating the increase or decrease in the volume of the working fluid and the index value indirectly indicating the increase or decrease in the volume of the working fluid. As a result, the position accuracy of the driven side piston of the driven side cylinder can be improved.

[0021] The molding machine in the second technical solution of the present invention comprises a fixed part, a movable part and a hydraulic circuit control device, the fixed part is equipped with a fixed metal mold, the movable part is equipped with a movable metal mold, the hydraulic circuit control device is arranged on the movable part, so that the movable part moves relative to the fixed part, the hydraulic circuit control device includes a driving motor, a driving side cylinder, a driven side cylinder and a liquid circuit volume adjustment mechanism, the driving side cylinder has a driving side liquid chamber, and a driving side piston moved by the driving motor, the driven side cylinder has a driven side liquid chamber, a liquid circuit connecting the driven side liquid chamber and the driving side liquid chamber, and a driven side piston that moves by the driving side piston and increases or decreases the amount of working fluid in the driven side liquid chamber via the liquid circuit, and the liquid circuit volume adjustment mechanism increases or decreases the volume of the liquid circuit according to the increase or decrease in the volume of the working fluid.

[0022] In the molding machine of the second technical solution of the present invention, as described above, a driving side cylinder, a driven side cylinder and a fluid path volume adjustment mechanism are provided, the driving side cylinder includes a driving side piston, the driven side cylinder includes a driven side piston that moves by the driving side piston and increases or decreases the amount of the working fluid in the driven side liquid chamber via the fluid path, and the fluid path volume adjustment mechanism increases or decreases the volume of the fluid path according to the increase or decrease in the volume of the working fluid. Thus, even if the volume of the working fluid increases or decreases due to temperature changes, leakage, etc. of the working fluid inside the fluid path, the driven side liquid chamber and the driving side liquid chamber, the fluid path volume adjustment mechanism can be used to increase or decrease the volume of the fluid path according to the increase or decrease in the volume of the working fluid. Therefore, by increasing or decreasing the volume of the fluid path through the fluid path volume adjustment mechanism, the increase or decrease in the volume of the working fluid can be absorbed, so that the increase or decrease in the volume of the working fluid does not affect the movement amount of the driven side piston. That is, the movement amount of the driven side piston can be corrected so that the movement amount of the driven side piston relative to the specified movement amount of the driving side piston is maintained approximately fixed. As a result, it is possible to provide a molding machine that can ensure the position accuracy of the slave-side piston of the slave-side cylinder even when the volume of the working fluid varies due to temperature changes, leakage, etc. of the working fluid.

[0023] In addition, in the hydraulic circuit control device of the first technical solution and the molding machine of the second technical solution, the following structure can also be considered.

[0024] (Additional item 1) That is, in the above-mentioned hydraulic circuit control device and molding machine, there is further provided a working fluid cooling passage which is provided in the fluid circuit and in which a coolant for cooling the working fluid in the fluid circuit flows.

[0025] According to this structure, the working fluid can be cooled by the working fluid cooling passage, so that the temperature rise of the working fluid can be suppressed, and the volume change of the working fluid itself caused by the temperature rise of the working fluid can be suppressed. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 This is a front view showing a press forming machine equipped with a hydraulic circuit control device according to an embodiment. Figure 2 It is a diagram showing the overall structure of the hydraulic circuit control device according to the embodiment. Figure 3 A diagram showing a fluid circuit volume adjustment mechanism of a hydraulic circuit control device according to an embodiment. Figure 4 A diagram showing a fluid circuit volume adjustment mechanism of a hydraulic circuit control device according to a modified example. DETAILED DESCRIPTION

[0027] Hereinafter, embodiments will be described based on the drawings.

[0028] [Implementation Method] (Structure of stamping machine) Reference Figure 1 to Figure 3 , the structure of a press forming machine 100 (an example of a “forming machine” in the technical claim) including a hydraulic circuit control device (hydraulic cylinder device) 101 according to the embodiment will be described.

[0029] like Figure 1 As shown, the press molding machine 100 includes a fixed portion 100a (bolster) to which a fixed die M1 is mounted, a movable portion 100b (slide) to which a movable die M2 is mounted, and a hydraulic circuit control device 101 provided on the movable portion 100b.

[0030] The press molding machine 100 is configured to open and close the fixed mold M1 and the movable mold M2 by moving the movable part 100b forward and backward in the vertical direction (direction B) relative to the fixed part 100a from above using the hydraulic circuit control device 101.

[0031] (Structure of hydraulic circuit control device) like Figure 2 As shown, the hydraulic circuit control device 101 includes a driving servomotor 1 (an example of a "driving motor" in the technical solution), a driving side ball screw mechanism 2, a driving side ball screw cooling passage 3, a driving side cylinder 4, a driven side cylinder 5 including fluid passages 50 and 51 connected to the driving side cylinder 4, and a working fluid cooling passage 6 (see Figure 3 ) and a liquid path volume adjustment mechanism 7. It should be noted that the liquid path volume adjustment mechanism 7 is provided one by one with respect to the liquid paths 50 and 51.

[0032] The driving side cylinder 4 and the driven side cylinder 5 are configured to mutually transport working fluid via the fluid paths 50 and 51 when the movable part 100b is moved forward or backward. The hydraulic circuit control device 101 is configured to move the driven side piston 53 of the driven side cylinder 5 forward (backward) by moving the driving side piston 41 of the driving side cylinder 4 forward (backward). The driven side cylinder 5 is a structure in which the movable part 100b of the stamping machine 100 is installed at the front end in the forward direction (B1 direction) of the driven side piston 53, and a propulsion force for moving the movable part 100b forward or backward is finally generated in the hydraulic circuit control device 101. It should be noted that, as an example, the above-mentioned working fluid refers to a liquid such as oil or water.

[0033] Here, the cross-sectional area of ​​the cross section orthogonal to the moving direction of the driven side piston 53 of the driven side cylinder 5 is larger than the cross-sectional area of ​​the cross section orthogonal to the moving direction of the driving side piston 41 of the driving side cylinder 4. Therefore, the hydraulic circuit control device 101 is configured to generate a larger propulsion force for moving the movable part 100b by using the driving side piston 41 and the driven side piston 53 for assisting. It should be noted that the cross-sectional area of ​​the driven side piston may also be less than or equal to the cross-sectional area of ​​the driving side piston. In the case where the cross-sectional area of ​​the driven side piston is smaller than the cross-sectional area of ​​the driving side piston, the moving speed (movement amount) of the driven side piston becomes greater than the moving speed (movement amount) of the driving side piston.

[0034] In each figure, the moving direction of the driving side piston 41 is represented by the A direction, the forward direction in the A direction is represented by the A1 direction, and the backward direction in the A direction is represented by the A2 direction. In addition, the axis extending in the A direction and located at the center of the driving side piston 41 and the driving side ball screw 21 is represented by the central axis α.

[0035] In each figure, the moving direction of the driven side piston 53 is indicated by B direction, the forward direction is indicated by B1 direction, and the backward direction is indicated by B2 direction. The B direction is also the moving direction of the movable part 100b of the press molding machine 100.

[0036] In each figure, the moving direction of the volume adjustment piston 72 of the fluid path volume adjustment mechanism 7 is indicated by the C direction, the forward direction in the C direction is indicated by the C1 direction, and the backward direction in the C direction is indicated by the C2 direction. It should be noted that when the volume adjustment piston 72 moves in the C1 direction, the volume of the fluid path 50 (51) decreases, and when the volume adjustment piston 72 moves in the C2 direction, the volume of the fluid path 50 (51) increases.

[0037] (Structure of driving servo motor) The driving servo motor 1 is configured to move the driving side piston 41 of the driving side cylinder 4 forward and backward in the A direction through the driving side ball screw mechanism 2. The driving side cylinder 4 is provided with a position detection unit 73a (an example of a "movement adjustment detection unit" in the technical solution) for detecting the position of the driving side piston 41. The driving servo motor 1 is provided with a control unit 1a for controlling the driving of the driving servo motor 1. The control unit 1a is configured to obtain the detection result of the position detection unit 73a through feedback and adjust the driving of the driving servo motor 1. In short, the liquid circuit volume adjustment mechanism 7 is configured to increase or decrease the volume of the liquid circuits 50 and 51 based on the piston position as an index value that directly shows the state of increase or decrease in the volume of the working fluid. In addition, the liquid circuit volume adjustment mechanism 7 is configured to increase or decrease the volume of the liquid circuits 50 and 51 based on the temperature of the working fluid as an index value that indirectly shows the state of increase or decrease in the volume of the working fluid. It should be noted that the index value that directly shows the state of increase or decrease in the volume of the working fluid is not limited to the piston position. Furthermore, the index value indirectly showing the state of increase or decrease in volume of the working fluid is not limited to the temperature of the working fluid, and may be the pressure of the working fluid or the like.

[0038] The control unit 1 a includes a computer numerical control (CNC) device that generates a pulse signal for driving the servo motor 1 , and a servo amplifier (driver) that drives the servo motor 1 based on the pulse signal.

[0039] The driving servo motor 1 includes a motor body 10 having a core, and a rotating shaft 11 (output shaft) that rotates around a central axis α through the motor body 10. A through hole 12 extending along the central axis α is formed in the motor body 10 and the rotating shaft 11. A refrigerant supply pipe 3a that supplies refrigerant to the drive side ball screw cooling passage 3 and a refrigerant discharge pipe 3b that discharges refrigerant from the drive side ball screw cooling passage 3 are arranged inside the through hole 12.

[0040] (Structure of the ball screw mechanism on the driving side) The driving side ball screw mechanism 2 connects the driving servo motor 1 and the driving side piston 41 of the driving side cylinder 4. The driving side ball screw mechanism 2 includes a driving side rotating nut 20 and a driving side ball screw 21. The driving side ball screw mechanism 2 is configured to be driven by the driving servo motor 1 so that the driving side piston 41 moves forward and backward in the A direction together with the driving side ball screw 21.

[0041] The driving side rotating nut 20 is mounted on the rotating shaft 11 that drives the servo motor 1. Therefore, the driving side rotating nut 20 is configured to rotate around the central axis α together with the rotating shaft 11 without moving in the A direction and maintaining the position in the A direction. The driving side ball screw 21 extends in the A direction while always being screwed with the driving side rotating nut 20. A driving side piston 41 is installed at the end of the driving side ball screw 21 in the A1 direction. The driving side ball screw 21 is arranged on the same axis as the driving side piston 41 of the driving side cylinder 4 (on the central axis α). The driving side ball screw 21 is configured to move in the A direction without rotating when the rotating shaft 11 rotates.

[0042] (Structure of cooling passage for ball screw on driving side) The driving side ball screw cooling passage 3 is provided inside the driving side ball screw 21. The driving side ball screw cooling passage 3 is configured so that a refrigerant for cooling the driving side ball screw 21 flows therein. As an example, the driving side ball screw cooling passage 3 is an elongated U-shaped passage extending along the length direction (direction A) of the driving side ball screw 21. The driving side ball screw cooling passage 3 is formed to be connected to the refrigerant supply pipe 3a and the refrigerant discharge pipe 3b at the end of the driving side ball screw 21 in the A2 direction, and is turned back near the end of the driving side ball screw 21 in the A1 direction.

[0043] When the driving side ball screw 21 moves at high speed together with the driving side piston 41, the temperature may rise significantly. In this case, the driving side ball screw cooling passage 3 suppresses the expansion of the driving side ball screw 21 by cooling the driving side ball screw 21, thereby suppressing the driving side rotating nut 20 screwed with the driving side ball screw 21 from hindering the movement of the driving side ball screw 21. In addition, the driving side ball screw cooling passage 3 suppresses the temperature increase of the working fluid around the driving side piston 41 via the driving side piston 41 mounted on the driving side ball screw 21 due to the temperature increase of the driving side ball screw 21.

[0044] (Structure of the drive side cylinder) The driving cylinder 4 includes a driving cylinder 40, a driving piston 41 moved by driving the servomotor 1, and driving liquid chambers 42a and 42b. The driving cylinder 40 and the driving piston 41 are provided with oil seals S1 for preventing (suppressing) leakage of the working fluid.

[0045] The driving side cylinder 40 is a hollow box body that accommodates the driving side piston 41 in a state that it can move in the front-back direction (direction A) and has driving side liquid chambers 42a and 42b inside. In addition, a position detection unit 73a for detecting the position of the driving side piston 41 is provided inside the driving side cylinder 40. The position detection unit 73a is a non-contact detection unit that detects the distance from the position detection unit 73a to the driving side piston 41 using light or magnetism, for example.

[0046] The driving side piston 41 divides the internal space of the driving side cylinder 40 into a driving side liquid chamber 42a on the A1 direction side and a driving side liquid chamber 42b on the A2 direction side. Thus, the working fluid in the driving side liquid chamber 42a and the working fluid in the driving side liquid chamber 42b are not mixed with each other.

[0047] When the driving side piston 41 moves forward (A1 direction), the working fluid flows out from the driving side liquid chamber 42a to the driven side cylinder 5 (driven side liquid chamber 54b) via the liquid path 50, and the working fluid flows from the driven side cylinder 5 (driven side liquid chamber 54a) into the driving side liquid chamber 42b via the liquid path 51.

[0048] In addition, when the driving side piston 41 moves backward (A2 direction), the working fluid flows from the driven side cylinder 5 (driven side liquid chamber 54b) into the driving side liquid chamber 42a via the liquid path 50, and the working fluid flows out from the driving side liquid chamber 42b to the driven side cylinder 5 (driven side liquid chamber 54a) via the liquid path 50.

[0049] (Structure of the slave cylinder) The slave cylinder 5 includes fluid passages 50 and 51, a slave cylinder 52, a slave piston 53, and slave fluid chambers 54a and 54b. The slave cylinder 52 and the slave piston 53 are provided with oil seals S2 for preventing (suppressing) leakage of the working fluid.

[0050] The fluid path 50 connects the driving side fluid chamber 42a and the driven side fluid chamber 54b. The fluid path 50, the driving side fluid chamber 42a, and the driven side fluid chamber 54b form a closed circuit that allows the working fluid to flow between the driving side fluid chamber 42a and the driven side fluid chamber 54b without changing the total amount of the working fluid inside. The closed circuit is filled with working fluid. However, the total amount of working fluid inside the fluid path 50, the driving side fluid chamber 42a, and the driven side fluid chamber 54b may decrease over time due to leakage of the working fluid through the oil seals S1 to S3.

[0051] The fluid path 51 connects the driving side liquid chamber 42b and the driven side liquid chamber 54a. The fluid path 51, the driving side liquid chamber 42b, and the driven side liquid chamber 54a form a closed circuit that allows the working fluid to flow between the driving side liquid chamber 42b and the driven side liquid chamber 54a without changing the total amount of the working fluid inside. The closed circuit is filled with working fluid. However, the total amount of working fluid inside the fluid path 51, the driving side liquid chamber 42b, and the driven side liquid chamber 54a sometimes decreases over time due to leakage of the working fluid through the oil seals S1 to S3. Plugs V are provided in the fluid paths 50 and 51 (see Figure 3 ).

[0052] The fluid path 50 includes a main fluid path portion 5a for allowing the working fluid to flow between the driven-side fluid chamber 54b and the driving-side fluid chamber 42a, and a regulating fluid path portion 5b connected to the main fluid path portion 5a (see Figure 3 The adjustment fluid path portion 5 b is arranged outside the driven-side cylinder portion 52 and the driving-side cylinder portion 40 .

[0053] The main liquid channel portion 5a is formed of a long and narrow pipe channel through which the working fluid passes. The main liquid channel portion 5a is a flow channel whose inner wall surface does not move but is fixed, and is configured so that the volume does not increase or decrease.

[0054] The regulating liquid path portion 5b is configured so that a part of the inner wall surface W can move, and the volume increases or decreases as the inner wall surface W moves. It should be noted that the inner wall surface W of the regulating liquid path portion 5b is composed of the front surface (the surface on the side of the liquid path 50) of the later-described volume regulating piston 72 of the liquid path volume regulating mechanism 7. The regulating liquid path portion 5b is a convex space that is connected to the main liquid path portion 5a from the side (cross direction) and protrudes from the main liquid path portion 5a to the side. The regulating liquid path portion 5b extends in the C direction while maintaining a cross-sectional shape orthogonal to the C direction. That is, the extension direction of the regulating liquid path portion 5b is approximately orthogonal to the extension direction of the main liquid path portion 5a. As an example, the regulating liquid path portion 5b is a cylindrical hollow space extending in the C direction. In addition, the liquid path 51 also has the same structure as the liquid path 50, including the main liquid path portion 5a and the regulating liquid path portion 5b.

[0055] The driven side cylinder 52 is a hollow box body that accommodates the driven side piston 53 in a state that it can move in the front-rear direction (B direction) and has driven side liquid chambers 54 and 54b inside. In addition, a position detection unit 73b that detects the position of the driven side piston 53 is provided inside the driven side cylinder 52. The position detection unit 73b is a non-contact detection unit that detects the distance from the position detection unit 73b to the driven side piston 53 using light or magnetism, for example.

[0056] The driven side piston 53 divides the internal space of the driven side cylinder 52 into a driven side liquid chamber 54a on the B1 direction side and a driven side liquid chamber 54b on the B2 direction side. Therefore, the working fluid in the driven side liquid chamber 54a and the working fluid in the driven side liquid chamber 54b do not mix with each other. The driven side piston 53 is configured so that when the driving side piston 41 moves, the amount of working fluid in the driven side liquid chambers 54a and 54b increases or decreases through the fluid paths 50 and 51, thereby moving the driven side piston 53.

[0057] Specifically, when the driving side piston 41 moves forward (in the A1 direction), the working fluid flows from the driving side liquid chamber 42a to the driven side liquid chamber 54b via the fluid path 50, thereby increasing the amount of working fluid in the driven side liquid chamber 54b, and the working fluid flows out from the driven side liquid chamber 54a to the driving side liquid chamber 42b via the fluid path 51, thereby reducing the amount of working fluid in the driven side liquid chamber 54a. As a result, the driven side piston 53 moves forward (in the B1 direction) together with the movable part 100b of the stamping machine 100. As a result, the fixed metal mold M1 (see Figure 1 ) is molded together with the movable metal mold M2.

[0058] In addition, when the driving side piston 41 moves backward (in the A2 direction), the working fluid flows out from the driven side liquid chamber 54b to the driving side liquid chamber 42a via the liquid path 50, so that the amount of working fluid in the driven side liquid chamber 54b is reduced, and the working fluid flows from the driving side liquid chamber 42b to the driven side liquid chamber 54a via the liquid path 51, so that the amount of working fluid in the driven side liquid chamber 54a is increased. As a result, the driven side piston 53 moves backward (in the B2 direction) together with the movable part 100b of the stamping machine 100. As a result, the fixed metal mold M1 and the movable metal mold M2 are opened.

[0059] (Structure of the working fluid cooling passage) Working fluid cooling passage 6 (see Figure 3 ) is provided in the liquid paths 50 and 51, and is configured so that the refrigerant cooling the working fluid in the liquid paths 50 and 51 flows therein. The working fluid cooling path 6 is arranged outside the liquid paths 50 and 51 in a state of contact with the liquid paths 50 and 51. The working fluid cooling path 6 is spirally wound around the liquid paths 50 and 51. The working fluid cooling path 6 is formed of a material with a high heat transfer coefficient. As an example, the working fluid cooling path 6 is formed of copper.

[0060] (Structure of the fluid path volume adjustment mechanism) The fluid path volume adjustment mechanism 7 is configured to increase or decrease the volume of the fluid path 50 (51) according to the increase or decrease in the volume of the working fluid. As a result, the fluid path volume adjustment mechanism 7 is configured to perform control so that the movement amount of the driven side piston 53 relative to the specified movement amount of the driving side piston 41 remains substantially constant. The increase or decrease in the volume of the working fluid is caused by the expansion or contraction of the working fluid due to leakage of the working fluid from the oil seals S1 to S3 or changes in the temperature of the working fluid.

[0061] As an example, the forward (B1 direction) movement amount of the driven side piston 53 is set to 50 mm relative to the forward (A1 direction) movement amount of the driving side piston 41 of 100 mm. Furthermore, when the actual forward (B1 direction) movement amount of the driven side piston 53 becomes 52 mm instead of 50 mm due to the expansion of the working fluid, the fluid path volume adjustment mechanism 7 is configured to move the volume adjustment piston 72 (inner wall surface W) backward to increase the volume of the adjustment fluid path portion 5b. As a result, the volume of the expanded working fluid can be absorbed by the enlarged adjustment fluid path portion 5b, so that the movement amount of the driven side piston 53 relative to the specified movement amount of the driving side piston 41 can be kept approximately constant.

[0062] The fluid path volume adjustment mechanism 7 includes a volume adjustment servo motor 70 (an example of a “volume adjustment motor” in the technical solution), a volume adjustment ball screw mechanism 71, a volume adjustment piston 72, a position detection unit 73a, a position detection unit 73b (an example of a “movement adjustment detection unit” in the technical solution), a liquid temperature detection unit 73c (an example of a “movement adjustment detection unit” in the technical solution), a hydraulic pressure detection unit 73d (an example of a “movement adjustment detection unit” in the technical solution), and a control unit 74.

[0063] The volume adjustment piston 72 is provided in the adjustment fluid path portion 5b of the fluid path 50 (51). The position detection portion 73a, the position detection portion 73b, the fluid temperature detection portion 73c, and the hydraulic pressure detection portion 73d are detection portions for adjusting the movement amount of the driven side piston 53 relative to the movement of the driving side piston 41. The fluid path volume adjustment mechanism 7 is configured to adjust the volume of the fluid path 50 (adjustment fluid path portion 5b) based on the detection results of the position detection portion 73a, the position detection portion 73b, the fluid temperature detection portion 73c, and the hydraulic pressure detection portion 73d.

[0064] like Figure 3 As shown, the volume adjustment servomotor 70 is configured to move the volume adjustment piston 72 forward and backward in the C direction via the volume adjustment ball screw mechanism 71 . The driving of the volume adjustment servomotor 70 is controlled by a control unit 74 .

[0065] The volume adjustment ball screw mechanism 71 connects the volume adjustment servomotor 70 and the volume adjustment piston 72. The volume adjustment ball screw mechanism 71 includes a volume adjustment rotating nut 71a and a volume adjustment ball screw 71b.

[0066] The volume adjustment ball screw mechanism 71 is configured to be driven by the volume adjustment servo motor 70, so that the volume adjustment piston 72 moves forward and backward together with the volume adjustment ball screw 71b in the C direction. The volume adjustment rotating nut 71a is attached to the rotating shaft 70a (output shaft) of the volume adjustment servo motor 70. Thus, the volume adjustment rotating nut 71a is configured to rotate together with the rotating shaft 70a while not moving in the C direction and maintaining the position in the C direction.

[0067] The volume adjusting ball screw 71b has a volume adjusting piston 72 mounted at the end in the C1 direction. The fluid path volume adjusting mechanism 7 is configured to increase or decrease the volume of the fluid path 50 (51) by moving the volume adjusting piston 72 (inner wall surface W) in the C direction together with the volume adjusting ball screw 71b.

[0068] The volume adjustment ball screw 71b extends in the C direction while always being screwed with the volume adjustment rotating nut 71a. A volume adjustment piston 72 is mounted on the end of the volume adjustment ball screw 71b in the C1 direction. The front surface (the surface on the C1 direction side) of the volume adjustment piston 72 constitutes the inner wall surface W of the adjustment fluid path portion 5b. An oil seal S3 is provided in the volume adjustment piston 72.

[0069] The volume adjusting piston 72 divides the adjusting fluid path 5b into a space on the C1 direction side filled with the working fluid and a space on the C2 direction side into which the working fluid does not flow. The volume adjusting piston 72 is configured to increase or decrease the volume of the adjusting fluid path 5b by moving the inner wall surface W in the C direction.

[0070] For example, when the volume adjustment rotating nut 71a rotates in one rotation direction (the R1 rotation direction indicated by the white arrow), the volume adjustment piston 72 moves in the C2 direction, so that the volume of the adjustment liquid path portion 5b increases. Since the volume of the main liquid path portion 5a remains unchanged, the volume of the entire liquid path 50 (51) increases only by the amount of the increase in the adjustment liquid path portion 5b.

[0071] In addition, when the volume adjustment rotating nut 71a rotates in the other rotation direction (the R2 rotation direction indicated by the black arrow), the volume adjustment piston 72 moves in the C1 direction, so that the volume of the adjustment liquid path portion 5b decreases. Since the volume of the main liquid path portion 5a remains unchanged, the volume of the entire liquid path 50 is also reduced by the amount of the reduction in the adjustment liquid path portion 5b.

[0072] Figure 2 The position detection portion 73b shown is configured to detect the position of the driving side piston 41. As described above, the position detection portion 73b is provided inside the driving side cylinder portion 40. The detection value of the position detection portion 73b is acquired by the control portion 1a and the control portion 74.

[0073] The position detection unit 73a is configured to detect the position of the driven-side piston 53. The position detection unit 73a is provided inside the driven-side tube portion 52. The detection value of the position detection unit 73a is acquired by the control unit 74.

[0074] The liquid temperature detection unit 73 c is configured to detect the temperature (state) of the working fluid. The liquid temperature detection unit 73 c is provided in the liquid path 50 ( 51 ). The detection value of the liquid temperature detection unit 73 c is acquired by the control unit 74 .

[0075] The hydraulic pressure detection unit 73d is configured to detect the pressure (state) of the hydraulic fluid. The hydraulic pressure detection unit 73d is provided in the fluid path 50 (51). The detection value of the hydraulic pressure detection unit 73d is acquired by the control unit 74.

[0076] The control unit 74 is configured to obtain the detection results of the position detection unit 73a, the position detection unit 73b, the liquid temperature detection unit 73c, and the hydraulic pressure detection unit 73d through feedback, and adjust the driving of the volume adjustment servo motor 70. The control unit 74 includes a computer numerical control (CNC) device that generates a pulse signal for driving the volume adjustment servo motor 70, and a servo amplifier (driver) that drives the volume adjustment servo motor 70 based on the pulse signal.

[0077] (Control structure of control unit) The control structure of the control unit 74 will be described.

[0078] The control unit 74 is configured to control the volume adjustment piston 72 (inner wall surface W) to move (advance) in the C1 direction to reduce the volume of the adjustment fluid path portion 5b when the movement amount of the driven side piston 53 relative to the specified movement amount of the driving side piston 41 is judged to be less than the set value (reference value) based on the detection values ​​of the position detection unit 73a and the position detection unit 73b when the temperature of the working fluid does not change. That is, the control unit 74 controls the working fluid in the adjustment fluid path portion 5b to be pushed into the main fluid path portion 5a. In this case, the reduction in the volume of the adjustment fluid path portion 5b is substantially equal to the reduction in the volume of the driven side liquid chamber 54a (driven side liquid chamber 54b) calculated based on the movement amount of the driven side piston 53 being less than the set value. As a result, the movement amount of the driven side piston 53 relative to the specified movement amount of the driving side piston 41 can be corrected to the set value. If the temperature of the hydraulic fluid does not change, the movement amount of the driven piston 53 relative to the specified movement amount of the driving piston 41 becomes smaller than the set value due to leakage of the hydraulic fluid, for example.

[0079] In addition, the control unit 74 is configured to, when there is no leakage of the working fluid, based on the detection value of the liquid temperature detection unit 73c, determine that the temperature of the working fluid is less than the set value, and consider the contraction rate of the working fluid relative to the temperature drop, and control the volume adjustment piston 72 (inner wall surface W) to move (advance) in the direction of C1 to reduce the volume of the adjusting liquid path portion 5b.

[0080] In addition, the control unit 74 is configured to, when there is no leakage of the working fluid, based on the detection value of the liquid temperature detection unit 73c, determine that the temperature of the working fluid is greater than the set value, and consider the expansion rate of the working fluid relative to the temperature rise, and control the volume adjustment piston 72 (inner wall surface W) to move (retreat) in the C2 direction to increase the volume of the adjusting liquid path portion 5b.

[0081] In addition, the control unit 74 is configured to control the volume adjustment piston 72 (inner wall surface W) to move (advance) in the C1 direction to increase the volume of the adjustment fluid path portion 5b when it is determined based on the detection value of the hydraulic pressure detection unit 73d that the pressure of the working fluid is (significantly) less than the set value (when it is determined that the pressure is less than a specified threshold value). It should be noted that when the pressure of the working fluid is (significantly) less than the set value (when it is determined that the pressure is less than a specified threshold value), the propulsion force of the movable portion 100b that moves together with the driven side piston 53 is insufficient, and the clamping force of the fixed metal mold M1 and the movable metal mold M2 cannot be fully exerted.

[0082] (Effects of this embodiment) In this embodiment, the following effects can be obtained.

[0083] In the present embodiment, as described above, the driving side cylinder 4, the driven side cylinder 5, and the fluid path volume adjustment mechanism 7 are provided, the driving side cylinder 4 including the driving side piston 41, the driven side cylinder 5 including the driven side piston 53 which is moved by the driving side piston 41 and increases or decreases the amount of the working fluid in the driven side liquid chambers 54a and 54b via the fluid paths 50 and 51, and the fluid path volume adjustment mechanism 7 increases or decreases the volume of the fluid paths 50 and 51 according to the increase or decrease in the volume of the working fluid. Thus, even if the volume of the working fluid increases or decreases due to temperature changes, leakage, etc. of the working fluid in the fluid paths 50 and 51, the driven side liquid chambers 54a and 54b, and the driving side liquid chambers 42a and 42b, the volume of the fluid paths 50 and 51 can be increased or decreased by the fluid path volume adjustment mechanism 7 according to the increase or decrease in the volume of the working fluid. Therefore, by increasing or decreasing the volume of the fluid paths 50 and 51 using the fluid path volume adjustment mechanism 7, the increase or decrease in the volume of the working fluid can be absorbed, so that the increase or decrease in the volume of the working fluid does not affect the movement amount of the slave side piston 53. That is, the movement amount of the slave side piston 53 can be corrected so that the movement amount of the slave side piston 53 relative to the specified movement amount of the driving side piston 41 is kept substantially constant. As a result, even if the volume of the working fluid changes due to temperature changes, leakage, etc. of the working fluid, the position accuracy of the slave side piston 53 of the slave side cylinder 5 can be ensured.

[0084] In the present embodiment, as described above, the fluid paths 50 and 51 include the main fluid path portion 5a that allows the working fluid to flow between the driven side fluid chambers 54a and 54b and the driving side fluid chambers 42a and 42b, and the regulating fluid path portion 5b connected to the main fluid path portion 5a, and the fluid path volume adjustment mechanism 7 includes the volume adjustment servo motor 70 that moves the inner wall surface W of the regulating fluid path portion 5b, and is configured to increase or decrease the volume of the regulating fluid path portion 5b by moving the inner wall surface W. Thus, the volume of the regulating fluid path portion 5b can be increased or decreased by moving the inner wall surface W of the regulating fluid path portion 5b by the volume adjustment servo motor 70, so that the movement amount of the driven side piston 53 can be easily corrected, and the position accuracy of the driven side piston 53 of the driven side cylinder 5 can be easily ensured.

[0085] In the present embodiment, as described above, in order to adjust the movement amount of the driven side piston 53 relative to the movement of the driving side piston 41, the fluid path volume adjustment mechanism 7 includes a movement adjustment detection unit (position detection units 73a, 73b, fluid temperature detection unit 73c, hydraulic pressure detection unit 73d) for detecting at least one of the positions of the driven side piston 53 and the driving side piston 41 and the state of the working fluid, and is configured to increase or decrease the volume of the fluid paths 50, 51 based on the detection results of the movement adjustment detection unit. Thus, the movement amount of the driven side piston 53 can be corrected based on the result obtained by detecting at least one of the positions of the driven side piston 53 and the driving side piston 41 and the state of the working fluid using the movement adjustment detection unit, so that the position accuracy of the driven side piston 53 of the driven side cylinder 5 can be more reliably ensured according to the positions of the driven side piston 53 and the driving side piston 41 and the state of the working fluid.

[0086] In the present embodiment, as described above, the movement adjustment detection unit includes at least one of the position detection units 73a and 73b for detecting the positions of the driving side piston 41 and the driven side piston 53, the liquid temperature detection unit 73c for detecting the temperature of the working fluid, and the hydraulic pressure detection unit 73d for detecting the pressure of the working fluid, and the fluid path volume adjustment mechanism 7 is configured to increase or decrease the volume of the fluid paths 50 and 51 based on the detection results of at least one of the position detection units 73a and 73b, the hydraulic pressure detection unit 73d, and the liquid temperature detection unit 73c. ​​Thus, it is possible to detect the positions of the driving side piston 41 and the driven side piston 53 indicating the change in the movement amount of the driven side piston 53 (the degree of deviation from the set value), and the temperature and pressure of the working fluid affecting the change in the movement amount of the driven side piston 53, so that the movement amount of the driven side piston 53 can be appropriately corrected according to various conditions.

[0087] In the present embodiment, as described above, the fluid path volume adjustment mechanism 7 includes a volume adjustment piston 72 and a volume adjustment ball screw mechanism 71, wherein the volume adjustment piston 72 is provided in the fluid paths 50 and 51, and the volume adjustment ball screw mechanism 71 has a volume adjustment ball screw 71b on which the volume adjustment piston 72 is mounted, and the volume of the fluid paths 50 and 51 is increased or decreased by moving the volume adjustment piston 72 together with the volume adjustment ball screw 71b. Thus, the volume adjustment piston 72 can be moved by the volume adjustment ball screw mechanism 71, so that the volume adjustment piston 72 can be moved with high precision, and the volume of the adjustment fluid path portion 5b can be adjusted with high precision.

[0088] In the present embodiment, as described above, the drive side ball screw mechanism 2 and the drive side ball screw cooling passage 3 are further provided. The drive side ball screw mechanism 2 has the drive side ball screw 21 to which the drive side piston 41 is mounted, and is driven by the drive servo motor 1 so that the drive side piston 41 moves together with the drive side ball screw 21. The drive side ball screw cooling passage 3 is provided inside the drive side ball screw 21, and a refrigerant for cooling the drive side ball screw 21 flows therein. Thus, the drive side ball screw 21 to which the drive side piston 41 is mounted can be cooled by the drive side ball screw cooling passage 3, so that the temperature rise of the working fluid caused by the drive side ball screw 21 and the drive side piston 41 can be suppressed, thereby suppressing the volume change of the working fluid itself caused by the temperature rise of the working fluid.

[0089] In the present embodiment, as described above, there is further provided a working fluid cooling passage 6 provided in the fluid passages 50 and 51 and through which a refrigerant for cooling the working fluid in the fluid passages 50 and 51 flows. Thus, the working fluid can be cooled by the working fluid cooling passage 6, so that a temperature rise of the working fluid can be suppressed, thereby suppressing a volume change of the working fluid itself caused by the temperature rise of the working fluid.

[0090] In the present embodiment, as described above, the fluid path volume adjustment mechanism 7 is configured to increase or decrease the volume of the fluid paths 50 and 51 based on both the index value that directly indicates the state of increase or decrease in the volume of the working fluid and the index value that indirectly indicates the state of increase or decrease in the volume of the working fluid. Thus, the volume of the working fluid can be increased or decreased with higher accuracy by taking into account both the index value that directly indicates the state of increase or decrease in the volume of the working fluid and the index value that indirectly indicates the state of increase or decrease in the volume of the working fluid. As a result, the position accuracy of the driven side piston 53 of the driven side cylinder 5 can be improved.

[0091] [Modifications] The embodiments disclosed this time should be considered as examples in all aspects and have no limiting effect. The scope of the present invention is not indicated by the description of the above embodiments but by the claims, and further includes all changes (modifications) within the scope of the claims and the meaning equivalent to the claims.

[0092] For example, in the above-mentioned embodiment, an example is shown in which the volume adjustment piston of the fluid path volume adjustment mechanism is directly mounted on the front end (the end in the C1 direction) of the volume adjustment ball screw, but the present invention is not limited to this. Figure 4As in the hydraulic circuit control device 201 shown in the figure, a plate member 272a is directly mounted on the front end (end in the C1 direction) of the volume adjustment ball screw 71b, and a spring member 272b is provided between the plate member 272a and the volume adjustment piston 272. The hydraulic circuit control device 201 can absorb (cushion) the impact applied to the driven side piston by the spring member 272b.

[0093] In addition, in the above-mentioned embodiment, the example in which the molding machine of the present invention is composed of a stamping molding machine is shown, but the present invention is not limited to this. In the present invention, the molding machine may also be composed of an injection molding machine, a die casting machine, etc.

[0094] In the above embodiment, an example is shown in which the hydraulic circuit control device is provided in a press forming machine (forming machine), but the present invention is not limited thereto. In the present invention, the hydraulic circuit control device may be provided in a machine tool, an inspection device, or the like.

[0095] In addition, in the above-mentioned embodiment, an example is shown in which the driving side liquid chamber on the front side of the driving side piston is connected to the driven side liquid chamber on the rear side of the driven side piston by one liquid circuit, and the driving side liquid chamber on the rear side of the driving side piston is connected to the driven side liquid chamber on the front side of the driven side piston by another liquid circuit, but the present invention is not limited to this. In the present invention, the driving side liquid chamber on the front side of the driving side piston and the driven side liquid chamber on the front side of the driven side piston may be connected by one liquid circuit, and the driving side liquid chamber on the rear side of the driving side piston and the driven side liquid chamber on the rear side of the driven side piston may be connected by another liquid circuit.

[0096] In addition, in the above embodiment, an example of configuring the working fluid cooling passage outside the fluid circuit is shown, but the present invention is not limited thereto. In the present invention, the working fluid cooling passage may also be configured inside the fluid circuit so that the working fluid cooling passage is in direct contact with the working fluid.

[0097] In the above embodiment, the example in which the drive motor of the present invention is constituted by a servo motor is shown, but the present invention is not limited thereto. In the present invention, the drive motor may be constituted by a different type of motor such as a stepping motor.

[0098] In addition, in the above-mentioned embodiment, an example is shown in which the liquid path includes two types of parts, namely, the main liquid path part and the regulating liquid path part, but the present invention is not limited thereto. In the present invention, the liquid path may also include only the liquid path part (main liquid path part) that allows the working fluid to flow between the driven side liquid chamber and the driving side liquid chamber. That is, the liquid path volume adjustment mechanism may also be configured to move the inner wall surface of the liquid path part (main liquid path part) that allows the working fluid to flow between the driven side liquid chamber and the driving side liquid chamber.

[0099] In addition, in the above embodiment, an example is shown in which the hydraulic circuit control device includes two fluid path volume adjustment mechanisms, but the present invention is not limited thereto. In the present invention, the hydraulic circuit control device may include one or three or more fluid path volume adjustment mechanisms.

[0100] In addition, in the above-mentioned embodiment, an example is shown in which the volume adjustment piston is mounted on the volume adjustment ball screw, and the volume adjustment piston is moved in the C direction together with the volume adjustment ball screw, but the present invention is not limited to this. In the present invention, the volume adjustment piston may also be mounted on the volume adjustment rotating nut, and the volume adjustment piston is moved in the C direction together with the volume adjustment rotating nut. In this case, the volume adjustment ball screw mechanism is configured in such a way that the volume adjustment ball screw does not move in the C direction.

[0101] In addition, in the above-mentioned embodiment, an example is shown in which the liquid circuit volume adjustment mechanism is configured to increase or decrease the volume of the liquid circuit based on both an indicator value that directly displays the state of increase or decrease in the volume of the working fluid and an indicator value that indirectly displays the state of increase or decrease in the volume of the working fluid, but the liquid circuit volume adjustment mechanism may also be configured to increase or decrease the volume of the liquid circuit based on only one of the indicator value that directly displays the state of increase or decrease in the volume of the working fluid and the indicator value that indirectly displays the state of increase or decrease in the volume of the working fluid. Explanation of symbols

[0102] 1 Driving servo motor (driving motor) 2. Drive side ball screw mechanism 3 Drive side ball screw cooling passage 4 Drive side cylinder 5 Slave side cylinder 5a Main fluid circuit 5b Adjustment fluid path 7 Liquid circuit volume adjustment mechanism 21 Drive side ball screw 41 Drive side piston 42a, 42b driving side liquid chamber 50, 51 Liquid circuit 53 Driven side piston 54a, 54b driven side liquid chamber 70 Servo motor for volume adjustment (motor for volume adjustment) 71 Ball screw mechanism for volume adjustment 71b Ball screw for volume adjustment 72, 272 Volume adjustment piston 73a Position detection unit (detection unit for movement adjustment) (detection unit for detecting the position of the driving side piston) 73b Position detection unit (detection unit for movement adjustment) (detection unit for detecting the position of the driven side piston) 73c Liquid temperature detection unit (detection unit for movement adjustment) 73d Hydraulic pressure detection unit (detection unit for movement adjustment) 100 Stamping machine (forming machine) 100a Fixed part 100b Movable part 101, 201 Hydraulic circuit control device M1 Fixed metal mold M2 movable metal mold W inner wall surface.

Claims

1. A hydraulic circuit control device, comprising: Drive motor; a drive-side cylinder including a drive-side liquid chamber and a drive-side piston moved by the drive motor; A driven side cylinder, the driven side cylinder comprising a driven side liquid chamber, a fluid path connecting the driven side liquid chamber and the driving side liquid chamber, and a driven side piston that moves by the driving side piston and increases or decreases the amount of working fluid in the driven side liquid chamber via the fluid path; and A fluid path volume adjustment mechanism increases or decreases the volume of the fluid path according to an increase or decrease in the volume of the working fluid.

2. The hydraulic circuit control device according to claim 1, wherein: The fluid path includes a main fluid path portion that allows the working fluid to flow between the driven-side fluid chamber and the driving-side fluid chamber, and a regulating fluid path portion connected to the main fluid path portion. The fluid path volume adjustment mechanism includes a volume adjustment motor that moves an inner wall surface of the adjustment fluid path portion, and is configured to increase or decrease the volume of the adjustment fluid path portion by moving the inner wall surface.

3. The hydraulic circuit control device according to claim 1, wherein: In order to adjust the movement amount of the driven side piston relative to the movement of the driving side piston, the fluid path volume adjustment mechanism includes a movement adjustment detection unit for detecting at least one of the positions of the driven side piston and the driving side piston, and the state of the working fluid, and is configured to increase or decrease the volume of the fluid path based on the detection result of the movement adjustment detection unit.

4. The hydraulic circuit control device according to claim 3, wherein: The movement adjustment detection unit includes at least one of a position detection unit for detecting the positions of the driving side piston and the driven side piston, a fluid temperature detection unit for detecting the temperature of the working fluid, and a fluid pressure detection unit for detecting the pressure of the working fluid. The fluid path volume adjustment mechanism is configured to increase or decrease the volume of the fluid path based on a detection result of at least one of the position detection unit, the hydraulic pressure detection unit, and the fluid temperature detection unit.

5. The hydraulic circuit control device according to claim 1, wherein: The liquid circuit volume adjustment mechanism comprises: a volume-adjusting piston, the volume-adjusting piston being disposed in the fluid path; and A volume adjustment ball screw mechanism includes a volume adjustment ball screw to which the volume adjustment piston is mounted, and increases or decreases the volume of the fluid path by moving the volume adjustment piston together with the volume adjustment ball screw.

6. The hydraulic circuit control device according to claim 1, further comprising: a driving side ball screw mechanism having a driving side ball screw to which the driving side piston is mounted and driven by the driving motor so that the driving side piston moves together with the driving side ball screw; and A driving side ball screw cooling passage is provided inside the driving side ball screw and a refrigerant for cooling the driving side ball screw flows therein.

7. The hydraulic circuit control device according to claim 1, wherein: The fluid path volume adjustment mechanism is configured to increase or decrease the volume of the fluid path based on at least one of an index value directly indicating a state of increase or decrease in volume of the working fluid and an index value indirectly indicating a state of increase or decrease in volume of the working fluid.

8. A molding machine comprising: A fixing part, wherein a fixing metal mold is installed on the fixing part; a movable part, the movable part having a movable metal mold installed therein; and a hydraulic circuit control device, the hydraulic circuit control device being provided at the movable part and causing the movable part to move relative to the fixed part, The hydraulic circuit control device comprises: Drive motor; a drive-side cylinder having a drive-side liquid chamber and a drive-side piston moved by the drive motor; A driven side cylinder, the driven side cylinder having a driven side liquid chamber, a fluid path connecting the driven side liquid chamber and the driving side liquid chamber, and a driven side piston that moves by the driving side piston and increases or decreases the amount of working fluid in the driven side liquid chamber via the fluid path; and A fluid path volume adjustment mechanism increases or decreases the volume of the fluid path according to an increase or decrease in the volume of the working fluid.

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