JP2007296562A - Method for detecting position of slider, and slider driving apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for detecting a position of a slider in driving the slider by means of a slider driving apparatus having a large diameter cylinder and a small diameter cylinder, and further to provide a slider driving apparatus. <P>SOLUTION: In the slider driving apparatus, the slider 3 is provided on a frame F so as to reciprocate, and the large diameter cylinder 5 and the small diameter cylinder 7 are integratedly provided to the slider 3, and the respective first chambers 5A, 7A of the large diameter cylinder 5 and the small diameter cylinder 7 are connected with each other, and the respective second chambers 5B, 7B of the large diameter cylinder 5 and the small diameter cylinder 7 are connected with each other. In the method for detecting the position of the slider, the moved position of the small diameter cylinder 7 with respect to the frame F is detected, and also the relative moved position of the small diameter cylinder 7 and a small diameter piston rod 7R provided in the small diameter cylinder 7 is detected. The moved position of the slider 3 with respect to the frame F is detected based on both detected values. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a slider position detecting method and a slider driving device in a slider driving device for driving a reciprocating slider by a fluid pressure mechanism such as a hydraulic cylinder, and more specifically, a large-diameter cylinder, The present invention relates to a slider position detecting method and a slider driving device in a slider driving device having a configuration having a small-diameter cylinder.

  As a configuration for driving a movable slider by a fluid pressure machine, a configuration in which a ram, a table, etc., as an example of a slider are reciprocated in various press machines (pressure machines), a bending machine, various machine tools, etc. It is employed as a configuration that reciprocates various moving members.

For example, a fluid pressure machine for reciprocating a ram (slider) in a press machine includes a large-diameter cylinder and a small-diameter cylinder, and a piston rod provided in the small-diameter cylinder so as to be reciprocally movable is a machine such as a ball screw mechanism. A configuration has been proposed in which a large output is obtained by reciprocating in a specific configuration to supply the working fluid in the small-diameter cylinder to the large-diameter cylinder (see Patent Document 1).
JP 2002-295624 A

  As shown in FIG. 3, the configuration described in Patent Document 1 includes a large-diameter cylinder 101. The large-diameter cylinder 101 includes a large-diameter piston 101P, and one of the large-diameter pistons 101P. A large-diameter piston rod 101R protrudes from the side and is provided as a ram. The inside of the large-diameter cylinder 101 is partitioned by the piston 101P into a first chamber 101A on the piston side and a second chamber 101B on the piston rod side.

  In order to supply pressurized working fluid to the large-diameter cylinder 101, a small-diameter cylinder 103 is provided, and the inside of the small-diameter cylinder 103 is a piston-side first chamber 103A by a small-diameter piston 103P. And the second chamber 103B on the rod side. A piston rod 103R integrally provided on one side of the small-diameter piston 103P is connected to a moving member 107 such as a ball nut provided in a freely reciprocating manner to a ball screw mechanism 105 that is rotationally driven by a motor M such as a servo motor. It is.

  The first chamber 101A of the large-diameter cylinder 101 and the first chamber 103A of the small-diameter cylinder 103 are connected by a connection path 109, and the second chamber 101B of the large-diameter cylinder 101 and the second chamber 103B of the small-diameter cylinder 103 are connected to each other. 111 is connected. An accumulator 113 is connected to the connection path 111.

  With the above configuration, when the motor M is driven and the small-diameter piston rod 103R is pressed and moved upward, the working fluid in the first chamber 103A of the small-diameter cylinder 103 is supplied into the first chamber 101A of the large-diameter cylinder 101. Therefore, the large diameter piston 101P and the piston rod 101R are lowered. Then, the working fluid in the second chamber 101 </ b> B of the large diameter cylinder 101 flows into the second chamber 103 </ b> B of the small diameter cylinder 103. In the reverse operation, the working fluid in the second chamber 103B of the small diameter cylinder 103 flows into the second chamber 101B of the large diameter cylinder 101, and the working fluid in the first chamber 101A of the large diameter cylinder 101 has a small diameter. It flows into the first chamber 103A of the cylinder 103.

  As described above, when the working fluid enters and exits between the first chamber 101A and the first chamber 103A of the large-diameter cylinder 101 and the small-diameter cylinder 103 and between the second chamber 101B and the second chamber 103B, When the flow rate on the chambers 101A and 103A side is Q1 and the flow rate on the second chambers 101B and 103B side is Q2, there is a relationship of Q1> Q2, and Q1 / Q2 must always be kept in a constant relationship.

  Therefore, the ratio NA of the pressure receiving area between the first chamber 101A and the second chamber 101B in the large diameter cylinder 101 and the ratio NB of the pressure receiving area between the first chamber 103A and the second chamber 103B in the small diameter cylinder 103 are NA = NB. It is necessary to hold in the relationship. Therefore, for example, when the large-diameter cylinder 101 is selected depending on the pressurizing capacity of the press machine, the small-diameter cylinder 103 is uniquely determined corresponding to the large-diameter cylinder 101, and the design flexibility is limited. There is a problem that is.

  Furthermore, in the above configuration, the large diameter piston rod 101R is reciprocated by the working fluid supplied from the small diameter cylinder 103 side. Therefore, in order to increase the stroke length of the large diameter piston rod 101R, the small diameter cylinder 103 is used. There is a problem that it must be long, and when the large-diameter piston rod 101R is moved at a high speed, the moving speed of the small-diameter piston rod 103R cannot be made almost the same as that of the small-diameter piston rod 103R. There is a problem in trying to.

  Further, in the conventional configuration, the first chamber 101A and the second chamber 101B in the large diameter cylinder 101 and the first chamber 103A and the second chamber 103B in the small diameter cylinder 103 are simply filled with a working fluid such as hydraulic fluid. Therefore, in order to increase the output of the large-diameter piston rod 101R, the time for increasing the pressure in the first chamber 101A in the large-diameter cylinder 101 to a desired pressure is relatively long. There is a problem in improving efficiency.

  In the conventional configuration, since the large-diameter cylinder 101 is fixed and the large-diameter piston rod 101R is reciprocated, the large-diameter piston rod 101R moves relative to a fixed portion such as a frame to which the large-diameter cylinder 101 is fixed. The position can be detected relatively easily. However, when the large-diameter piston rod 101R is fixed to the fixed portion and the large-diameter cylinder 101 moves relative to the fixed portion, the large-diameter cylinder 101 can be accurately detected only by detecting the rotation with the motor M. Therefore, there is a problem that it is necessary to provide an expensive linear sensor or the like between the fixed portion and the large-diameter cylinder 101.

  The present invention has been made in view of the conventional problems as described above, and connects the first chambers of a large-diameter cylinder and a small-diameter cylinder that are integrally provided on a slider that is reciprocally movable in a frame. In the slider position detecting method in the slider driving device configured to connect the second chambers, the moving position of the small diameter cylinder with respect to the frame is detected, and the small diameter piston rod provided in the small diameter cylinder and the small diameter cylinder The relative movement position is detected, and the movement position of the slider with respect to the frame is detected based on the detection values obtained by the both detections.

  Also, a slider driving device having a configuration in which the first chambers of the large-diameter cylinder and the small-diameter cylinder provided integrally with the slider provided in the frame so as to be capable of reciprocating are connected and the second chambers are connected. A first position detecting means for detecting a moving position of the small diameter cylinder relative to the frame; and a relative moving position of the small diameter piston rod provided in the small diameter cylinder and the small diameter cylinder. And a second position detecting means.

  Further, in the slider driving device, the second position detecting means includes a rotation operation mechanism that rotates when the small diameter piston rod moves relative to the small diameter cylinder, and detects the rotation of the rotation operation mechanism. It is characterized by being.

  According to the present invention, it is possible to select the diameters of the large diameter cylinder and the small diameter cylinder as desired diameters, and the degree of freedom in design is large, the moving position of the small diameter cylinder with respect to the frame, and the small diameter piston rod with respect to the small diameter cylinder. Therefore, it is possible to detect the movement position and the movement speed of the slider that moves integrally with the small-diameter cylinder with respect to the fixed portion such as the frame.

  Referring to FIG. 1 conceptually and schematically showing an embodiment according to the present invention, in this embodiment, a slider driving device for driving a slider reciprocated by a fluid pressure mechanism is applied to a press machine. Although the case is illustrated, the present invention is not limited to a press machine, and drives various moving members as sliders that are movable in the vertical and horizontal directions in, for example, a bending machine and various machine tools. The configuration can also be applied.

  Now, the press machine (pressure machine) 1 according to the present embodiment includes a ram 3 as an example of a reciprocating slider (moving member). A large-diameter cylinder 5 and a small-diameter cylinder 7 are integrally attached to the ram (slider) 3. Since the large-diameter cylinder 5 and the small-diameter cylinder 7 have an integral configuration, they can be provided in one cylinder block and unitized for compactness.

  A large-diameter piston 5P is housed in the large-diameter cylinder 5 so as to be able to reciprocate. On both sides of the large-diameter piston 5P, large-diameter pistons having the same diameter with end portions protruding from the large-diameter cylinder 5 to the outside. A rod 5R is provided. One end portion or both end portions of the large-diameter piston rod 5R are connected and fixed to a fixing portion 9 such as a frame F of the press machine 1. The inside of the large-diameter cylinder 5 is partitioned into a first chamber 5A and a second chamber 5B by the large-diameter piston 5P, and a connection path 11 that connects and communicates the first chamber 5A and the second chamber 5B. Is provided with an on-off valve 13 such as a solenoid valve which can freely cut off the connection path 11.

  A small-diameter piston 7P is housed in the small-diameter cylinder 7 so as to be able to reciprocate, and on both sides of the small-diameter piston 7P, small-diameter piston rods 7R having the same diameter and projecting from the small-diameter cylinder 7 to the outside are provided. ing. One end of the small-diameter piston rod 7R is connected to a moving member 17 that is reciprocated by driving a motor 15 such as a servo motor.

  The inside of the small diameter cylinder 7 is divided into a first chamber 7A and a second chamber 7B by the small diameter piston 7P, and the first chamber 7A in the small diameter cylinder 7 and the first chamber 5A in the large diameter cylinder 5 operate. A connection path 19A as an example of a fluid introduction path is connected, and a switching valve (open / close valve) 21A such as a solenoid valve is disposed in the connection path 19A. Further, the second chamber 7B in the small diameter cylinder 7 and the second chamber 5B in the large diameter cylinder 5 are connected via a connection path 19B.

  Further, the first chamber 7A and the second chamber 7B in the small-diameter cylinder 7 are connected via a connection path 31, and the connection path 31 is, for example, a solenoid valve or the like that can freely cut off the connection path 31. An on-off valve (switching valve) 31A is arranged.

  The pressure receiving area of the large diameter piston 5P is several to several tens of times larger than the pressure receiving area of the small diameter piston 7P. The large-diameter cylinder and the small-diameter cylinder do not mean the size of the cylinder itself, but the size of the pressure receiving area of the internal piston. Further, the length of the small diameter cylinder 7 may be the same length as the large diameter cylinder 5, or may be long or short.

  The moving member 17 only needs to be configured to reciprocate directly or indirectly by the rotational drive of the motor 15, and in this example, a power transmission mechanism such as a timing belt is provided by the motor 15. In this example, the ball nut is moved by rotating the ball screw. However, the configuration for reciprocating the moving member 17 is not limited to the ball screw mechanism as described above, and any mechanism can be employed.

  In the configuration as described above, as shown in FIG. 1, the small-diameter piston 7P is held in contact with the upper end of the small-diameter cylinder 7 so as to be integrally lowered, and the on-off valve 13 is held open. When the first chamber 5A and the second chamber 5B in the large-diameter cylinder 5 are in communication with each other, when the motor 15 is rotationally driven to move the moving member 17 downward, the small-diameter piston is driven by the weight of the ram 3. 7P is held in contact with the upper end of the small diameter cylinder 7, and the ram 3 is lowered by its own weight. At this time, in the large-diameter cylinder 5, the working fluid flows from the first chamber 5A into the second chamber 5B, and the lowering speed of the ram 3 etc. is equal to the lowering speed of the moving member 17 and moves at a high speed. It is.

  In the configuration shown in FIG. 1, both the on-off valves 21A and 31A are held closed, the small-diameter cylinder 7 is locked, and the motor 15 is rotated at a high speed, so that the ram 3 is faster than the descent speed due to its own weight. It is something that can descend.

  Thus, when the small-diameter cylinder 7 is held in the locked state and the large-diameter cylinder 5 and the ram 3 are moved together, the moving position and moving speed of the ram (slider) 3 with respect to the fixed portion such as the frame F are as follows: This can be detected by detecting the rotation of the motor 15 or the ball screw 23.

  As described above, the on-off valve 13 is closed when the ram 3 is lowered and pressure is applied. Further, when the on-off valve 21A is held in the closed state, it is opened. Accordingly, the small-diameter piston 7P descends relative to the small-diameter cylinder 7, the working fluid in the second chamber 7B in the small-diameter cylinder 7 is pressurized by the small-diameter piston 7P, and the second chamber 5B in the large-diameter cylinder 5 is pressed. Flows in. The working fluid in the first chamber 5 </ b> A in the large diameter cylinder 5 flows into the first chamber 7 </ b> A in the small diameter cylinder 7. At this time, the flow rate of the working fluid flowing out from the second chamber 7B in the small diameter cylinder 7 is equal to the flow rate of the working fluid flowing into the first chamber 7A.

  As described above, when the working fluid is supplied from the second chamber 7B in the small diameter cylinder 7 to the second chamber 5B in the large diameter cylinder 5 to lower the ram 3, the pressure receiving area of the large diameter piston 5P and the small diameter piston 7P is reduced. Corresponding to the ratio, the lowering speed of the ram 3 becomes lower and the applied pressure becomes larger. When the ram 3 is raised, the moving member 17 may be moved upward. Also in this case, the ram 3 can be raised at a low speed and at a high speed. At this time, by holding the switching valves (open / close valves) 21A and 31A in the closed state and the open / close valve 13 in the open state, the ram 3 is immediately moved from the lowered position to the high speed corresponding to the rotational speed of the motor 15. It is also possible to rise.

  When the on-off valve 31A is held open, the first chamber 7A and the second chamber 7B in the small diameter cylinder 7 are in communication with each other, and the working fluid is supplied from the small diameter cylinder 7 side to the large diameter cylinder 5 side. The small diameter piston 7P and the small diameter piston rod 7R are relatively movable with respect to the small diameter cylinder 7.

  And in the said description, the large diameter piston rod 5R was fixed to the fixing | fixed part 9, and the case where the large diameter cylinder 5 moved was demonstrated. However, fixing the large-diameter piston rod 5R or fixing the large-diameter cylinder 5 is only relative to whether the output in the fluid pressure cylinder is on the cylinder side or on the piston rod side. is there. Accordingly, the large-diameter cylinder 5 can be fixed to the fixed portion 9 and the large-diameter piston rod 5R can be connected to the ram 3.

  Furthermore, the moving direction of the small-diameter piston 7P on the small-diameter cylinder 7 side and the moving direction of the large-diameter piston 5P on the large-diameter cylinder 5 side can be the same direction or opposite directions. That is, the first chamber 7A in the small diameter cylinder 7 and the second chamber 5B in the large diameter cylinder 5 are connected, and the second chamber 7B in the small diameter cylinder 7 and the first chamber 5A in the large diameter cylinder 5 are connected. Is also possible.

  In the above-described configuration, an accumulator is connected to each of the first chamber 5A and the second chamber 5B of the large-diameter cylinder 5 via an on-off valve, and the first chamber 5A, the second chamber 5B, and each accumulator are connected. It is also possible to adopt a configuration in which the working fluid enters and exits, and in this case, the connection path 11 and the on-off valve 13 can be omitted.

  As already understood, according to the configuration as described above, the ram 3 can be moved at a high speed in conjunction with the rotational speed of the motor 15, and the working fluid is supplied from the small diameter cylinder 7 to the large diameter cylinder 5. By operating the ram 3, the ram 3 can be moved at a low speed and with a large output.

  In order to detect the movement position when the ball screw 23 is rotated by the rotation drive of the motor 15 and the small diameter cylinder 7, the large diameter cylinder 5 and the ram (slider) 3 are moved from the reference position of the highest position, for example. In order to hold the motor 5 in a fixed state, the motor 15 is provided with a rotation position detecting means 33 such as a rotary encoder and a fixing means 35 such as a brake.

  Therefore, by rotating the motor 15, the moving position when the small-diameter cylinder 7 and the like are moved from the reference position via the moving member 17 and the moving speed at that time are detected by the rotating position detecting means 33. Can do. Then, by operating a brake as an example of the fixing means 35, the rotation of the motor 15 can be held in a stopped state.

  Further, in order to detect the relative movement of the small diameter piston 7P and the small diameter piston rod 7R with respect to the small diameter cylinder 7 and to fix the small diameter cylinder 7 and the small diameter piston rod 7R integrally, the small diameter cylinder 7 and the small diameter cylinder 7 An integral fixing means 37 is provided between the piston rod 7R.

  More specifically, a ball nut 41 in a ball screw mechanism is integrally attached to a bracket 39 provided integrally with the small diameter cylinder 7, and a ball screw 43 parallel to the small diameter piston rod 7R is attached to the ball nut 41. It is screwed (screwed) so as to be relatively rotatable. One end of the ball screw 43 is rotatably supported by a bracket 45 that is integrally attached to the small-diameter piston rod 7R.

  A position detecting means 47 such as a rotary encoder rotatably supported by the bracket 45 and a fixing means 49 such as a brake are a large-diameter pulley attached to one end of the ball screw 43, the position detecting means 47 and the fixing means 49. The ball screw 43 is linked to the ball screw 43 via a working force transmission mechanism 51 such as a structure in which a timing belt is wound around a small-diameter pulley integrally provided with the means 49.

  Since it is relative whether the bracket 39 is provided with the ball nut 41 or the bracket 45 is provided with the ball nut 41, the structure of the integrated fixing means 37 is turned upside down so that the ball nut is attached to the bracket 45. 41, and the bracket 39 may include a position detecting means 47 and a fixing means 49.

  With the above configuration, when the small-diameter piston rod 7 </ b> R moves relative to the small-diameter cylinder 7, the ball screw 43 moves up and down relatively while rotating with respect to the ball nut 41. Accordingly, the position detecting means 47 rotates in conjunction with the rotation of the ball screw 43 to detect the rotation of the ball screw 43. Therefore, the relative moving distance, moving position and moving position of the small diameter piston rod 7R with respect to the small diameter cylinder 7 are as follows. The speed can be detected.

  When the ball screw 43 is fixed so as not to rotate by the fixing means 49, the small diameter cylinder 7 and the small diameter piston rod 7R are integrated. Therefore, by holding the ball screw 43 in a locked state by the fixing means 49 and holding the on-off valve 13 in an open state, the ball screw 23 is rotated by the motor 15 to mechanically move the slider (ram) 3. Is something that can be done.

  As already understood, when the slider is moved by the rotation of the motor 15, the moving position of the slider 3 from the reference position and the moving speed at that time are detected by the rotating position detecting means 33 that rotates in conjunction with the motor 15. can do. Further, when the small-diameter piston rod 7R moves relative to the small-diameter cylinder 7 in a state where the rotation of the motor 15 is stopped, the small-diameter cylinder 7 is detected by the position detecting means 47 provided in the integrated fixing means 37. The relative movement position of the small-diameter piston rod 7R from the relative reference position (for example, the position where the small-diameter piston 7P is located at the stroke end on one end side of the small-diameter cylinder 7) and the relative position of the small-diameter piston rod 7R The moving speed can be detected.

  Therefore, the moving position of the slider 3 from the reference position and the moving speed at that time can be detected based on the detected value by the rotational position detecting means 33 and the detected value by the position detecting means 47. Therefore, when the small diameter piston rod 7R is appropriately moved with respect to the small diameter cylinder 7, the small diameter cylinder 7 and the small diameter piston rod 7R are integrated by the integrated fixing means 37, and the ball screw 23 is rotated by the motor 15. Even when the slider 3 is moved, the position of the slider 3 can always be accurately detected.

  By the way, in the configuration as described above, the slider (ram) 3 is moved as described above and, for example, a pressed member (not shown) to be pressed like a workpiece to be processed is pressed with a desired pressing force. In order to achieve this, it is necessary to increase the pressure in the second chamber 5B of the large-diameter cylinder 5 to a desired pressure. Here, in the state where the first chambers 5A and 7A and the second chambers 5B and 7B in the large-diameter cylinder 5 and the small-diameter cylinder 7 are simply filled with a working fluid such as oil, the internal pressure is almost zero and the desired pressure is reached. The pressure is increased to a certain level, and it takes time to increase the pressure.

  Therefore, in the present embodiment, the working fluid filled in the fluid pressure circuit including the first chambers 5A and 7A and the second chambers 5B and 7B of the large-diameter cylinder 5 and the small-diameter cylinder 7 is a predetermined pressure higher than atmospheric pressure. Pre-pressurized to pressure. In order to preliminarily pressurize the fluid pressure in the fluid pressure circuit to a pressure equal to or higher than the atmospheric pressure, the fluid pressure circuit is provided with a pressure applying means 53.

  In more detail, in order to facilitate understanding in this example, an appropriate position of the fluid pressure circuit including the first chambers 5A and 7A and the second chambers 5B and 7B of the large-diameter cylinder 5 and the small-diameter cylinder 7 is large. The pressure applying means 53 is connected to the first chamber 5 </ b> A of the diameter cylinder 5. The pressure applying means 53 is provided with a booster 55. The booster 55 includes a large-diameter air cylinder 61 connected to an air source 59 via a circuit switching valve 57 made of a solenoid valve or the like. In this air cylinder 61, a piston rod 61R reciprocated by switching the air inflow direction by the circuit switching valve 57 is integrated with a small-diameter piston rod 63R that is reciprocally fitted in a small-diameter hydraulic cylinder 63. Are connected.

  Therefore, when the piston rod 61R in the air cylinder 61 is protruded and the small-diameter piston rod 63R is pressed into the hydraulic cylinder 63, the pressure oil in the hydraulic chamber 63A in the hydraulic cylinder 63 is pressurized and discharged. Is. In addition, since the structure of this kind of booster 53 is well-known, the more detailed description about the structure of the booster 53 is abbreviate | omitted.

  The pressure oil chamber 63A of the hydraulic cylinder 63 and the first chamber 5A of the large diameter cylinder 5 are connected via a connection path 65. The connection path 65 is connected to the first chamber from the pressure oil chamber 63A. A check valve 67 that allows the flow of pressure oil (working fluid) only to the 5A side is arranged. A branch path 69 branched and connected to the connection path 65 between the check valve 67 and the first chamber 5A has a first accumulator cylinder 71 connected to the air source 59 and given a constant back pressure. Connected.

  Furthermore, a bypass passage 77 in which a relief valve 73 and a check valve 75 are connected in series is connected to the check valve 67 in parallel. A second accumulator cylinder 81 connected to the air source 59 and applied with back pressure is connected to a branch passage 79 that is branched and connected between the relief valve 73 and the check valve 75.

  In the above configuration, the on-off valves 13, 21A, 31A are opened, and the first chamber 5A, the second chamber 5B in the large diameter cylinder 5 and the first chamber 7A, the second chamber 7B in the small diameter cylinder 7 communicate with each other. When in the state, the connection of the circuit switching valve 57 is switched, air is supplied to the air cylinder 61, and the piston rod 61R is operated to protrude, so that the pressure oil in the pressure oil chamber 63A of the hydraulic cylinder 63 is moved by the piston rod 63R. Pressurized and discharged.

  Accordingly, the pressurized working fluid is supplied to the first chamber 5A of the large diameter cylinder 5 via the connection path 65, and the first chamber 5A, the second chamber 5B of the large diameter cylinder 5 and the first chamber of the small diameter cylinder 7 are supplied. The pressure in the fluid pressure circuit including 7A and the second chamber 7B is increased to a predetermined pressure higher than the atmospheric pressure. When the circuit switching valve 57 is switched to return the piston rod 61R of the air cylinder 61 to the initial position, the piston rod 63R in the hydraulic cylinder 63 is also returned to the original position, and the hydraulic oil in the hydraulic cylinder 63 is restored. The working fluid is supplied from the second pressure accumulating cylinder 81 and filled in the chamber 63A.

  As described above, the on-off valves 13 and 21A are held in the open state, and the small diameter cylinder 7 and the small diameter piston rod 7R are integrated by the integrated fixing means 37 or the slider 3 is lowered by its own weight. When the ball screw 23 is rotated by the motor 15 and the small diameter cylinder 7, the large diameter cylinder 5 and the slider 3 are lowered in FIG. 1, the working fluid in the first chamber 5 </ b> A in the large diameter cylinder 5 passes through the connection path 11 and the opening / closing valve 13. It flows into the second chamber 5B.

  Thereafter, when the on / off valve 13 is switched to the closed state when the slider 3 is lowered to an appropriate position, the working fluid in the second chamber 7B of the small-diameter cylinder 7 flows into the large-diameter cylinder 5B from this point in time, and the large-diameter The working fluid in the first chamber 5 </ b> A of the cylinder 5 flows into the first chamber 7 </ b> A of the small diameter cylinder 7. At this time, as shown in FIG. 1, in a state where the large-diameter cylinder 5 is raised with respect to the large-diameter piston rod 5P, the pressure in the first chamber 5A in the large-diameter cylinder 5 is higher than the pressure in the second chamber 5B. Since the large-diameter cylinder 5 is relatively raised by slightly increasing the pressure, the pressure P1 in the first chamber 5A is the pressure in the second chamber 5B as shown on the left side of FIG. It is held at a slightly higher pressure than P2. Thereafter, after the slider 3 comes into contact with the pressed object (from time T1 in FIG. 2), the pressure in the second chamber 5B gradually increases, and the pressure in the first chamber 5A gradually decreases to almost atmospheric pressure. Get closer.

  Thereafter, when the pressure in the second chamber 5B of the large-diameter cylinder 5 rises to the desired pressure P3 by the slider 3 pressing the pressed object, the desired pressure P4 (P4 = (second chamber) on the pressed object is reached. The pressure in 5B−the pressure in first chamber 5A) × area) is obtained. The applied pressure is substantially zero until time T1 when the on-off valve 13 is closed, and the applied pressure is rapidly increased from time T1 to time T2 when the pressure in the first chamber 5A is close to atmospheric pressure. It rises proportionally from time T2 to time T3 when the desired pressure P3 is reached.

  By the way, the pressure in the second chamber 5B in the large-diameter cylinder 5 is initially P2 which is equal to or higher than atmospheric pressure, and rises proportionally from the pressure P2 to the pressure P3. It is shortened by (T4−T3) than the time up to the time point T4 that rises proportionally. Accordingly, the time for increasing the pressure to the pressure P3 for obtaining the desired pressure P4 is shortened, and the working efficiency can be improved.

  When the pressure in the first chamber 5 </ b> A in the large-diameter cylinder 5 becomes higher than the back pressure acting on the first pressure accumulating cylinder 71, the working fluid flows into the first pressure accumulating cylinder 71. When the pressure in the first chamber 5A becomes equal to or higher than a preset set pressure, the working fluid flows into the second pressure accumulation cylinder 81 through the relief valve 73. Therefore, the pulsation when the large-diameter cylinder 5 is moved up and down relative to the large-diameter piston 5P is absorbed by the pressure accumulating cylinders 71 and 81, and the large-diameter cylinder 5 is smoothly operated. is there.

  The present invention is not limited to the configuration as described above, and can be implemented in various machines and devices having a configuration in which a pressing member as an example of a slider such as a filter press reciprocates in the horizontal direction. Is something.

It is explanatory drawing which showed notionally and schematically the structure of the slider drive device which concerns on embodiment of this invention. It is explanatory drawing which shows the mode of the pressure change in the 1st chamber in a large diameter cylinder, and a 2nd chamber. It is operation | movement explanatory drawing of the conventional slider drive device.

Explanation of symbols

1 Press machine (pressurizing machine)
3 Ram (slider)
5 Large-diameter cylinder 5A 1st chamber 5B 2nd chamber 5P Large-diameter piston 5R Large-diameter piston rod 7 Small-diameter cylinder 7A 1st chamber 7B 2nd chamber 7P Small-diameter piston 7R Small-diameter piston rod 11 Connection 13 Open / close valve 15 Motor 17 Moving member 19A, 19B Connection path 23, 43 Ball screw 33 Rotation position detection means (rotary encoder)
35, 49 Fixing means (brake)
37 Integrated fixing means 41 Ball nut 47 Position detection means (rotary encoder)
53 Pressure Applying Means 55 Booster 59 Air Source 61 Air Cylinder 63 Hydraulic Cylinder 63A Hydraulic Chamber

Claims (3)

  In a slider driving apparatus having a configuration in which a first chamber of a large-diameter cylinder and a small-diameter cylinder provided integrally with a slider provided in a reciprocating manner in a frame is connected and provided, and each second chamber is connected. In the slider position detection method, the movement position of the small diameter cylinder with respect to the frame is detected, the relative movement position of the small diameter piston rod provided in the small diameter cylinder and the small diameter cylinder is detected, and based on the detection value by the both detections. A slider position detecting method, comprising: detecting a moving position of the slider with respect to the frame.   A slider driving device having a structure in which a first chamber of a large-diameter cylinder and a small-diameter cylinder provided integrally with a slider that is reciprocally mounted on a frame is connected and a second chamber is connected. A first position detecting means for detecting a moving position of the small diameter cylinder relative to the frame, and a second position for detecting a relative moving position between the small diameter piston rod provided in the small diameter cylinder and the small diameter cylinder. And a position detecting means.   3. The slider drive device according to claim 2, wherein the second position detection means includes a rotation operation mechanism that rotates when the small diameter piston rod moves relative to the small diameter cylinder, and detects the rotation of the rotation operation mechanism. The slider drive device characterized by the above-mentioned.

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