JP2012152783A - Slider drive device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a slider drive device achieving smooth reciprocation when reciprocating a slider by a hydraulic mechanism integrally including large diameter cylinders and small diameter cylinders in parallel.SOLUTION: This slider drive device includes: large cylinder bodies 17A which are provided in the large diameter cylinders 17 with piston rods fixed to frames and which are integrally provided to the slider; small pistons 19P relatively reciprocatingly provided inside of small cylinder bodies 19A integrally provided with the large cylinder bodies 17A; first chambers inside of the large cylinder bodies 17A and first chambers inside of the small cylinder bodies 19 which communicate with each other; second chambers inside of the large cylinder bodies 17A and second chambers inside of the small cylinder bodies 19A which communicate with each other; first actuators 27 for reciprocating the large cylinder bodies 17; and second actuators 29 for reciprocating the small pistons 19P with respect to the small cylinder bodies.

Description

  The present invention relates to a slider driving device for reciprocating a reciprocating slider such as a ram by a fluid pressure mechanism having a structure in which a large-diameter cylinder and a small-diameter cylinder are integrally provided in parallel. When the slider is moved at a high speed by a small diameter cylinder and the slider is moved at a low speed by a large diameter cylinder with a large applied pressure, the movement when moving from the small diameter cylinder to the large diameter cylinder is smoothly performed. The present invention relates to a slider drive device that can be used.

  As a prior example for reciprocating a slider such as a ram by a fluid pressure mechanism having a structure in which a large-diameter cylinder and a small-diameter cylinder are integrally provided in parallel, there is Patent Document 1.

JP 2007-296561 A

  In the above-mentioned Patent Document 1, a configuration in which a ram as an example of a slider moves up and down is a configuration in which a large-diameter cylinder is integrally connected to the ram and a piston rod of the large-diameter cylinder is connected to a frame. . The piston rod provided in the small diameter cylinder integrally provided in parallel with the large diameter cylinder is configured to move up and down by a screw mechanism. When the ram is moved up and down by integrally moving the large diameter cylinder and the small diameter cylinder up and down and then moving up and down the piston rod of the small diameter cylinder, in order to switch the vertical movement speed of the ram, An open / close valve is provided in the connection path connecting the upper and lower fluid pressure chambers in the small diameter cylinder. In addition, an opening / closing valve is provided in the connection path connecting the upper and lower fluid pressure chambers of the large diameter cylinder, and an opening / closing valve is provided in the connection path connecting the upper chambers of the large diameter cylinder and the small diameter cylinder.

  In the above configuration, when the vertical movement speed of the ram is switched, the opening / closing of each on-off valve is switched. Therefore, there is a problem that it is difficult to adjust the timing of the opening / closing operation of each on-off valve in order to smoothly move the ram up and down. In addition, although there is only one motor for driving the screw mechanism, it is necessary to provide a position detecting means for detecting the relative vertical movement position of the piston rod with respect to the small diameter cylinder, and further improvement is required. ing.

  The present invention has been made in view of the conventional problems as described above, and is a slider driving device that reciprocates a slider that is reciprocated by a fluid pressure mechanism, and is a large-sized cylinder in which a piston rod is fixed to a frame. A cylinder body is integrally provided on the slider, and a small piston is relatively reciprocally movable in a small cylinder body integrally provided with the large cylinder body. The first chamber in the large cylinder body and the small chamber are provided. In order to reciprocate the large cylinder body, the first chamber in the cylinder body is provided in communication with the second chamber in the large cylinder body and the second chamber in the small cylinder body is provided in communication. And a second actuator for reciprocating the small piston with respect to the small cylinder body. That.

  In the slider drive device, a logic valve is provided in the connection circuit connecting the first chamber and the second chamber in the large cylinder body so that the connection circuit can be disconnected and disconnected. It is.

  According to the present invention, the first actuator for reciprocating the cylinder body of the large-diameter cylinder integral with the slider and the second actuator for reciprocating the piston with respect to the small-diameter cylinder are provided. It is possible to smoothly switch between the operation of reciprocating the slider by operating the small diameter cylinder and the operation of reciprocating the slider by operating the large diameter cylinder, and the slider can be moved smoothly. is there.

It is a perspective explanatory view of a slider drive device concerning an embodiment of the present invention. It is explanatory drawing which shows the structure which act | operates a large diameter cylinder and a small diameter cylinder. It is explanatory drawing which shows the arrangement | positioning positional relationship of a large diameter cylinder, a small diameter cylinder, and a motor.

  Referring to FIG. 1, a press brake 1 as an example of a slider driving device according to an embodiment of the present invention includes left and right columnar side frames 3L and 3R, and upper and lower portions of the side frames 3L and 3R. Are integrally connected by upper and lower connecting beams 5U, 5L. A lower table 7 is integrally attached to the lower portions of the side frames 3L and 3R, and an upper table 9 as an example of a slider is provided on the upper portions of the side frames 3L and 3R so as to be movable up and down. The upper table 9 is formed in a rectangular shape that is long in the left-right direction, and the left and right side surfaces 11L, 11R are formed in vertical surfaces. In addition, in order to suppress the upper table 9 from being bent upward in a convex shape due to a reaction force at the time of bending a plate-like workpiece (not shown), the upper table 9 is convex upward. It is also possible to provide curved curved protrusions.

  The upper table 9 that can move up and down constitutes a ram, and the slider also reciprocates in the same manner as the ram. Therefore, the upper table 9 and the slider are referred to as rams 9 as a synonym. To do.

  Vertical operation devices 13L and 13R for moving the ram (slider) 9 up and down are provided on the lateral sides of the left and right side frames 3L and 3R in the horizontal direction. The left and right vertical actuators 13L and 13R have the same configuration and are arranged symmetrically. Therefore, the configuration of the right vertical actuator 13R will be described in detail, and regarding the left vertical actuator 13L, components having the same functions in the configuration will be denoted by the same reference numerals and description thereof will be omitted.

  As conceptually and schematically shown in FIG. 2, the vertical movement device 13R (13L) includes a large-diameter cylinder 17 and a small-diameter cylinder 19 as vertical movement actuators 15 for moving the ram 9 up and down. The cylinder body 17A of the large-diameter cylinder 17 and the cylinder body 19A of the small-diameter cylinder 19 are provided in parallel and integrally. The piston 17P, which is mounted in the large cylinder body 17A so as to be relatively movable up and down, is provided with a piston rod 17R penetrating the large cylinder body 17A in both the up and down directions, and the upper end portion of the piston rod 17R is It is integrally connected to the upper part of the frame 3R. A piston 19P is mounted in the small cylinder body 19A of the small diameter cylinder 19 integrated with the large diameter cylinder 17 so as to be relatively movable up and down. The piston rod 19R provided to the piston 19P is a small cylinder main body. 19A is penetrated in both the upper and lower directions.

  The upper chamber 21U as the first chamber in the large-diameter cylinder 17 and the upper chamber 23U as the first chamber in the small-diameter cylinder 19 are connected to each other via a connection path 25U. The lower chamber 21L as the second chamber in the large-diameter cylinder 17 and the lower chamber 23L as the second chamber in the small-diameter cylinder 19 are connected to each other via a connection path 25L.

  The large-diameter cylinder 17 is integrated with the side surfaces 11L and 11R of the ram 9 in order to move the ram 9 up and down (reciprocating) as the slider by operating the large-diameter cylinder 17 and the small-diameter cylinder 19 in the vertical-motion actuator 15. Installed. A first motor 27 is provided as a first actuator for operating the large-diameter cylinder 17, and a second motor 29 is provided as a second actuator for operating the piston rod 19R of the small-diameter cylinder 19. Is provided.

  More specifically, a screw mechanism 31 is provided on the outer lateral surfaces of the side frames 3L and 3R in order to move the large-diameter cylinder 17 in the vertical movement actuator 15 up and down. That is, a screw member 33 having a lower end portion fixed integrally to the side frames 3L and 3R is erected vertically on the outer surfaces of the side frames 3L and 3R. The upper end portion of the screw member 33 may be fixed to the side frames 3L and 3R integrally or may be a free end that is not fixed.

  A nut member 37 supported by the bracket 35 provided integrally with the cylinder main body 19A of the small-diameter cylinder 19 so as to be rotatable only is screwed to the screw member 33 so as to be movable up and down. The nut member 37 is rotatably supported by a motor bracket 41 which is supported by a vertical guide portion (guide rail) 39 provided in the side frames 3L and 3R so as to be movable up and down.

  The first motor 27 is mounted on the motor bracket 41, and a belt 47 is wound around a driving pulley 43 provided on the first motor 27 and a driven pulley 45 provided on the nut member 37. . That is, the first motor 27 and the nut member 37 are interlocked and connected. The first motor 27 is provided with a rotary encoder 49 as an example of detection means. Further, a brake 51 for stopping the rotation of the first motor 27 is provided.

  Therefore, the large diameter cylinder 17 and the small diameter cylinder 19 can be moved up and down integrally by rotating the nut member 37 forward and backward by the first motor 27. The rotary encoder 49 can detect the moving speed and moving position of the large-diameter cylinder 17 in the vertical direction from the vertical reference position.

  In order to operate the small-diameter cylinder 19 in the vertical movement actuator 15, a bracket 53 integrally connected to the upper end portion or the lower end portion of the piston rod 19R is provided. The bracket 53 includes the screw member 33. A nut member 55 that is screwed to be vertically movable is rotatably supported. Further, the nut member 55 is rotatably supported by a motor bracket 57 that is guided and supported by the guide portion 39 so as to be movable up and down. A belt 63 is wound around a driving pulley 59 of the second motor 29 supported by the motor bracket 57 and a driven pulley 61 provided in the nut member 37. The second motor 29 is provided with a rotary encoder 65 as an example of detection means and a brake 67.

  Therefore, the piston 19P can be moved up and down with respect to the cylinder body 19A of the small diameter cylinder 19 by rotating the second motor 29 forward and backward. At this time, the rotary encoder 65 can detect the vertical movement position of the piston 19P with respect to the reference position of the cylinder body 19A. Therefore, when the piston 19P is moved up and down relatively with respect to the cylinder body 19A, the volume of the working fluid flowing in and out through the large-diameter cylinder 17 can be calculated through the connection paths 25U and 25L.

  The upper chamber 21U and the lower chamber 21L in the large-diameter cylinder 17 are connected via a connection path 69, and a relief valve 71 is disposed in the connection path 69. A bypass path 73 as a connection path is connected in parallel to the relief valve 71, and a logic valve 75 that can freely disconnect the bypass path 73 is disposed in the bypass path 73. When the back pressure of the internal spool 75S is high, the logic valve 75 cuts off the communication of the bypass passage 73. When the back pressure is low, the logic valve 75 is a working fluid from the upper chamber 21U to the lower chamber 21L in the large-diameter cylinder 17. The action which permits the flow of is made.

  In order to control the back pressure of the logic valve 75 against the spool 75S, a connection path 77 connected to the lower chamber 21L of the large-diameter cylinder 17 is connected to the back pressure chamber 75R of the logic valve 75. A 4-port 2-position electromagnetic switching valve 79 is disposed in the path 77. In the back pressure chamber 75 </ b> R of the logic valve 75, a spring that presses and urges the spool 75 </ b> S in a direction that blocks the bypass path 73 is provided.

  A connection path 81 connected to a booster 80 is connected to the upper chamber 21U in the large-diameter cylinder 17, and a check valve that allows only a flow of working fluid in the direction of the upper chamber 21U is connected to the connection path 81. 83 is arranged. The check valve 83 is provided with a relief valve 85 that allows the working fluid to flow from the upper chamber 21U toward the booster 80. Further, a first pressure accumulator 87 is connected in parallel to the relief valve 85, and a second pressure accumulator 89 is connected in parallel to the booster 80. An air source 91 is connected to the booster 80 and the first and second pressure accumulators 87 and 89. A switching valve 82 is provided between the booster 80 and the air source 91 so that the supply of air to the large-diameter chamber 80A and the small-diameter chamber 80B in the booster 80 can be switched. In addition, since the effect | action of the booster 80 and the 1st, 2nd pressure accumulator 87,89 is well-known as described in the said patent document 1, description about the effect | action of the booster 80 is abbreviate | omitted.

  In the configuration as described above, as shown in FIG. 2, the cylinder body 17A of the large-diameter cylinder 17 is in the most elevated state with respect to the piston 17P, and the piston 19P is elevated to the cylinder body 19A of the small-diameter cylinder 19. When in the state, the ram 9 is in the highest position with respect to the side frames 3L and 3R. As described above, when the ram 9 is in the highest state, the switching valve 79 is switched so that the back pressure chamber 75R of the logic valve 75 is connected to the tank T, and the first motor 27 is rotated forward to rotate the screw. When the nut member 37 is lowered with respect to the member 33, the large-diameter cylinder 17 and the small-diameter cylinder 19 are integrally lowered, and the ram 9 is lowered. At this time, the working fluid in the upper chamber 21U in the large-diameter cylinder 17 flows into the lower chamber 21L through the bypass path 73 and the logic valve 75, and the ram 9 is lowered at a high speed.

  As described above, when the large-diameter cylinder 17 and the small-diameter cylinder 19 are lowered, the bracket 53 is lowered by the piston rod 19R. At this time, the second motor 29 may be free or may rotate in synchronization with the rotation of the nut member 55 that is rotated by the lowering of the bracket 53.

  Thereafter, when the switching valve 79 is switched to the state shown in FIG. 2, the logic valve 75 blocks the communication of the bypass path 73 due to the difference in the pressure receiving area of the spool 75S in the logic valve 75 and the action of the spring in the back pressure chamber 75R. become. In this way, when the logic valve 75 is in a state of blocking the bypass path 73, when the second motor 29 is rotated forward and the nut member 35 is rotated forward and lowered with respect to the screw member 33, the small cylinder 19 is moved. The piston 19P is lowered. Therefore, the working fluid in the lower chamber 23 </ b> L in the small cylinder 19 flows into the lower chamber 21 </ b> L of the large cylinder 17. The working fluid in the lower chamber 21U of the large diameter cylinder 17 flows into the upper chamber 23U of the small cylinder 19.

  Therefore, due to the difference in diameter between the large cylinder 17 and the small cylinder 19, the cylinder body 17A and the ram 9 in the large cylinder 17 descend at a low speed. Further, since the large cylinder 17 has a larger diameter than the small cylinder 19, the pressure applied to the ram 9 increases.

  As already understood, the ram 9 can be moved up and down at high speed by driving the first motor 27, and the ram 9 can be moved up and down at low speed by driving the second motor 29. The driving of the first motor 27 and the driving of the second motor 29 can be overlapped, that is, both the first and second motors 27 and 29 can be driven. Switching from high speed movement to low speed movement and switching from low speed movement to high speed movement of the ram 9 can be performed smoothly, and the movement of the ram 9 can be performed smoothly without causing pulsation or the like.

  By the way, in the said structure, when the upper metal mold | die (illustration omitted) with which the ram 9 was equipped performs the press work (bending process) of the workpiece | work positioned on the lower metal mold | die (illustration omitted) with which the lower table 7 was equipped. The reaction force is received by the left and right side frames 3L, 3R via the piston rod 17R of the large-diameter cylinder 17. At this time, since the side frames 3L and 3R are columnar unlike the C-shaped side frame in the conventional general press brake, the side frames 3L and 3R are displaced vertically upward. Inclination such that the upper side becomes the rear side can be suppressed, and high accuracy can be achieved.

  Further, the lower end portions of the vertical screw members 33 in the vertical operation devices 13L and 13R are fixed to the lower end portions of the side frames 3L and 3R, and the upper end portions are configured as free ends, so that the side frames 3L and 3R Even if the upper part is deformed, for example, curved, the screw member 33 is not affected by the deformation. Therefore, the vertical movement position of the ram 9 can be detected by the rotary encoders 49, 65 provided in the first and second motors 27, 29.

  Therefore, conventionally, in order to support the sensor for detecting the vertical movement position of the ram, an inverted L-shaped sensor support member having a lower end fixed to the lower portion of the side frame is provided, but the sensor support member is omitted. Therefore, the structure can be simplified.

  By the way, the large-diameter cylinder 17 is integrally attached to the left and right side surfaces of the ram 9, and the small-diameter cylinder 19 is disposed behind the large-diameter cylinder 17 and outside the side frames 3L and 3R. . A motor 27 for moving the large-diameter cylinder 17 up and down and a motor 29 for operating the piston rod 19R of the small-diameter cylinder 19 are rearward (rear side) of the small-diameter cylinder 19 as schematically shown in FIG. ). Therefore, the width dimension in the left-right direction of the overall configuration can be suppressed.

  The load center 93 (see FIG. 3) of the load acting on the large-diameter cylinder 17 and the load acting on the small-diameter cylinder 19 when the ram 9 performs a pressurizing operation is the longitudinal direction of the side frames 3L and 3R. Are arranged in an intersecting region 95 between the region and the virtual extending portion in the left-right direction of the ram 9. Therefore, the reaction force when the ram 9 is pressed downward by the large-diameter cylinder 17 and the workpiece is pressed is received in the intersecting region 95. Therefore, when the workpiece is pressed, the side frames 3L and 3R are not subjected to a bending moment that tends to bend in the left-right direction in FIG. 3, and high accuracy can be achieved. .

  The present invention is not limited to the configuration as described above, and can be implemented in other forms by making appropriate changes. For example, in the configuration schematically and conceptually shown in FIG. 2, the first motor 27 is illustrated below the motor bracket 41. However, a configuration in which the first motor 27 is disposed above the motor bracket 41 is also possible.

  Further, the piston rod 19R in the small diameter cylinder 19 may be configured as a hollow pipe, and the screw member 33 may be inserted into the piston rod 19R of the pipe so as to be relatively movable up and down. In the case of this configuration, the nut members 37 and 55 are respectively screwed into the portion where the screw member 43 protrudes upward from the piston rod 19R of the small-diameter cylinder 19 and the portion where the screw member 43 protrudes downward so as to freely move up and down. In the first motor 27, the motor bracket 41 is integrally supported by a motor standing bracket 99 (see FIG. 1) that stands integrally with the small diameter cylinder 19.

  According to the above configuration, since the screw member 33 is inserted into the piston rod 19R of the small diameter cylinder 19, the overall configuration can be made more compact.

  FIG. 1 illustrates a press brake in the case of the above configuration.

1 Press brake 3L, 3R Side frame 7 Lower table 9 Ram (Slider, Upper table)
11L, 11R Left and right side surfaces 13L, 13R Vertical actuator 15 Vertical actuator 17 Large diameter cylinder 17A Cylinder body 19 Small diameter cylinder 19A Cylinder body 27 First motor 29 Second motor 31 Screw mechanism 33 Screw member 37 Nut member 49 Rotary encoder (Detection means)
51 Brake 55 Nut member 65 Rotary encoder (detection means)
67 Brake

Claims (2)

  A slider driving device for reciprocatingly driving a slider reciprocated by a fluid pressure mechanism, wherein a large cylinder body in a large-diameter cylinder having a piston rod fixed to a frame is provided integrally with the slider, and is integrated with the large cylinder body. A small piston is relatively reciprocally movable in the small cylinder body provided in the apparatus, and a first chamber in the large cylinder body and a first chamber in the small cylinder body are provided in communication with each other. A second chamber in the main body and a second chamber in the small cylinder main body are provided in communication with each other, a first actuator for reciprocating the large cylinder main body is provided, and the small cylinder main body is A slider driving device comprising a second actuator for reciprocating a piston.   2. The slider drive device according to claim 1, wherein a logic valve capable of freely disconnecting the connection circuit is provided in a connection circuit connecting the first chamber and the second chamber in the large cylinder body. A slider driving device.

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