JP2008142718A - Stretch bending machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a stretch bending machine which can improve the working efficiency of its adjusting work, and also can accurately detect the generating timing of abnormal pressure to be generated in a hydraulic cylinder. <P>SOLUTION: The measuring portion 51 of an internal pressure sensor 50 is arranged inside a piston rod side pressure chamber 27. Further, a moved length detecting device 54 to be composed of a rotary encoder 55 is arranged to a piston rod 25 so as to measure the moved length from a preset reference position. In addition, rotary encoders 60 are arranged on lap arm portions 5 so as to measure turned angles from a preset reference angular position. In this configuration, when abnormal pressure is measured in the piston rod side pressure chamber 27 by means of the internal pressure sensor 50, the moved length of the piston rod 25 and the turned angles of the lap arm portions 5 at that time are informed by means of a monitor 65. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a stretch bender machine having a hydraulic cylinder.

  2. Description of the Related Art A stretch bender machine that curves a long workpiece along a mold having a predetermined shape while pulling in a longitudinal direction is well known (for example, see Patent Document 1). More specifically, the stretch bender machine has a hollow cylinder tube in which hydraulic oil is contained, a piston portion slidably disposed in the cylinder tube, the piston portion being connected to the end, and A hydraulic cylinder is provided that includes a rod-shaped piston rod connected to a tension chuck that holds a workpiece at the tip. The stretch bender machine also includes a lap arm portion that is linked to the hydraulic cylinder and rotates to the left and right within a predetermined angle range. When the lap arm portion rotates in a predetermined manner, the workpiece can be elastically deformed into a curved shape and brought into pressure contact with the mold while the workpiece is pulled with a predetermined tensile force by the hydraulic cylinder. A bent product having a desired shape is manufactured by such a series of molding processes.

  By the way, when a large tensile force is abruptly applied to the hydraulic cylinder, the piston rod side pressure chamber defined in the cylinder tube becomes a high pressure and an abnormal pressure is generated. If an abnormal pressure is generated in this way, an unnecessary load is applied to the bent portion of the workpiece, which causes a problem that the workpiece is wrinkled or broken at the bent portion. In view of such a problem, Patent Document 1 discloses a configuration that appropriately eliminates abnormal pressure generated during molding.

JP 2005-282644 A

However, the conventional configuration disclosed in Patent Document 1 also has the following problems.
Before reaching a stage where mass production of defect-free bent products is possible, it is necessary to set in advance the tensile force of the hydraulic cylinder or the complicated operation mode of the lap arm. Specifically, the operation mode of the lap arm part, etc. is finely adjusted many times to find the optimum workpiece tensile force, workpiece bending start timing, workpiece bending direction, workpiece bending speed, etc. We are trying to build an operating system for producing bent products. However, conventionally, in such a pre-adjustment stage, an operator cannot objectively grasp whether or not an abnormal pressure is generated in the hydraulic cylinder, or when the abnormal pressure is generated. It was out. For this reason, it is necessary for the operator to empirically predict the occurrence of the abnormal pressure and perform machine adjustment, and it is necessary to use a highly skilled technique to identify an appropriate operation mode. Further, when there is no advanced technology, useless adjustment work increases and work efficiency is lowered, and as a result, product productivity and processing accuracy may be lowered.

  In the configuration disclosed in Patent Document 1, since the internal pressure sensor is provided in the pipe connected to the hydraulic cylinder, the flow resistance caused by the pipe adversely affects the measurement result of the internal pressure sensor, and the accuracy of the measurement result is improved. It has also been found that there is room for.

  In view of the above, an object of the present invention is to provide a stretch bender machine capable of improving the work efficiency of the adjustment work and accurately knowing the generation timing of the abnormal pressure generated in the hydraulic cylinder.

  The present invention relates to a hollow cylinder tube into which hydraulic oil is charged, a piston part slidably disposed in the cylinder tube, a piston part connected to the end, and a mold having a predetermined shape at the tip. The piston rod side pressure chamber and the cap side pressure chamber are defined in the cylinder tube by the piston portion. A hydraulic cylinder and an operating part linked to the hydraulic cylinder, and the operating part operates in a predetermined manner to pull the work through the hydraulic cylinder and to move the work along the mold. In a stretch bender machine that performs a series of forming processes to be bent, the internal pressure measuring means for measuring the internal pressure of the piston rod side pressure chamber, and the piston An operation displacement value detecting means for detecting an operation displacement value, which is a displacement value from a predetermined reference position of the head and / or the operation section, and an internal pressure measuring means during the molding process based on a predetermined reference internal pressure. When measuring a higher internal pressure, the stretch bender machine is provided with a motion displacement value notifying means for notifying the motion displacement value of the piston rod and / or the motion part at that time.

  In such a configuration, in the process of forming the workpiece, the piston rod connected to the workpiece via the holding means moves back and forth to generate a predetermined tensile force. Further, the operation unit moves back and forth or rotates around a predetermined rotation center. The present invention has a configuration in which an operation displacement value detecting means is appropriately provided in an operation part that operates in the molding process as described above, and the detected operation displacement value is reported so that the operator can grasp it. Accordingly, the operator who performs the above-described adjustment work can make a hydraulic cylinder by referring to the operation displacement value of the piston rod or the like at the time when the internal pressure (abnormal pressure) higher than the reference internal pressure is generated by the notification of the operation displacement value notification means. It becomes possible to sequentially perform the optimum setting for the tensile force and the operation of the operating part. Thereby, useless work is reduced in the above-described adjustment work, and the work time is shortened, and a stretch bender machine capable of efficiently mass-producing bent products can be set. In addition, various aspects can be proposed for the configuration for notifying the motion displacement value. For example, the structure which alert | reports by screen display and the structure alert | reported by audio | voice output are mentioned. In short, any notification mode that allows the operator to recognize the motion displacement value may be used.

  Further, in the above configuration, an operation time measuring means for measuring an operation time that is an elapsed time from a timing at which the piston rod and / or the operation unit starts to operate from a predetermined reference position, and an internal pressure measurement during the molding process When the means measures an internal pressure higher than a predetermined reference internal pressure, a configuration including an operation time notifying means for notifying the operation time of the piston rod and / or the operation unit at that time is proposed.

  In such a configuration, the operator who performs the above-described adjustment work grasps the operation displacement value of the piston rod and the like at the time when the internal pressure (abnormal pressure) higher than the reference internal pressure is generated, and the operation time as described above. Is possible. That is, by grasping the motion displacement value and the motion time, it is possible to grasp the elapsed time until the abnormal pressure is generated and the motion displacement value of the motion section at that time. Further, by grasping the motion displacement value and the motion time, it is possible to grasp the motion speed of the piston rod or the like until the abnormal pressure is generated. Therefore, the operator can perform the optimum machine setting while referring to the operation state of the piston rod or the like when the abnormal pressure is generated.

  In addition, a configuration is proposed in which the internal pressure measuring means includes a measuring unit, and the measuring unit is disposed in the piston rod side pressure chamber.

  By adopting such a configuration, the adverse effect of the flow resistance due to the piping is eliminated when measuring the internal pressure, so that the internal pressure of the piston rod side pressure chamber can be accurately measured. As a result, the occurrence of abnormal pressure is detected with high accuracy, so that the reliability of the operation displacement value of the piston rod or the like during the measurement of abnormal pressure is improved, and highly accurate adjustment work is possible.

  The stretch bender machine of the present invention is configured to notify the operation displacement value of the piston rod and / or the operation unit at the time when the internal pressure measuring unit measures an internal pressure higher than the reference internal pressure. It becomes possible to grasp the operation displacement value of the piston rod or the like at the time point, and it becomes possible to reset the optimum operation of the piston rod or the like with reference to the notified operation displacement value during the adjustment work. As a result, the adjustment work becomes simpler than before, so that even if it is not a skilled worker, there is an effect that a certain machining accuracy can be secured, and unnecessary adjustment work is eliminated and work efficiency is improved. There is. In addition, shortening the working time has the effect of improving product productivity.

  Further, in the above configuration, when the internal pressure measuring means measures the operation time of the piston rod and / or the operation unit at the time when the internal pressure higher than the reference internal pressure is measured, and the configuration notifies the operation time, There is an effect that it is possible to reset the optimum operation of the piston rod or the like with reference to the notified operation time. Further, it is possible to grasp the operation speed of the piston rod or the like at the time when the abnormal pressure occurs, and it is possible to reset the optimum operation of the piston rod or the like based on this operation speed.

  In addition, when the internal pressure measuring means is such that the measuring part is arranged in the piston rod side pressure chamber, the internal pressure in the piston rod side pressure chamber can be measured accurately, so that the piston rod at the time of abnormal pressure measurement etc. This improves the reliability of the operation displacement value and enables an adjustment operation with high accuracy.

An embodiment of a stretch bender machine according to the present invention will be described with reference to the accompanying drawings.
As shown in FIG. 1, the stretch bender machine 1 includes a support base 2 fixed to the floor at the center. A plate-shaped mold table 3 is disposed at the upper end of the support table 2. A bending mold 4 is detachably disposed on the upper surface of the mold table 3.

  As shown in FIGS. 1 and 2, a mold surface 14 including a plane portion and a curved surface portion is formed on the side surface of the bending mold 4. Then, the metal workpiece W is sequentially pressed against the mold surface 14 in a surface contact manner, whereby a desired bent product is obtained. The bending die 4 is appropriately replaced according to the shape of the bending product to be manufactured.

  As shown in FIGS. 1 and 2, lap arm portions 5 and 5 project horizontally from both side portions of the support base 2. Here, a connecting portion 15 having a U-shaped longitudinal section is provided at the base ends of both wrap arm portions 5. Further, the connection portion 15 is linked to a vertical rotation shaft 16 disposed on the support base 2, and the connection portion 15 and the rotation shaft 16 constitute a shaft support portion 9. And the lap arm part 5 rotates right and left centering on the axis | shaft support part 9 by the rotation axis | shaft 16 rotating around an axis line (arrow direction in FIG. 2). In addition, since both the lap arm parts 5 are the same structures, below, one lap arm part 5 is demonstrated.

  Further, a tension post 6 is disposed upright on the upper edge of the lap arm portion 5 and substantially in the middle. The tension post 6 is movable along the upper edge of the lap arm portion 5 and can be appropriately changed in position according to the entire length of the workpiece W to be processed. In addition, the tension post 6 according to the present embodiment is fixed to the lap arm portion 5 and cannot be moved during the molding process.

  Further, as shown in FIG. 2, a support rod 8 is horizontally supported by the tension post 6. Further, the support rod 8 can move up and down along the tension post 6. Further, a horizontal hydraulic cylinder 10 is connected to the support rod 8, and when the support rod 8 moves up and down along the tension post 6, the hydraulic cylinder 10 also moves up and down. ing. The hydraulic cylinder 10 is connected to a vertically moving hydraulic cylinder 11 arranged in an upright manner, and the vertical movement speed can be changed as appropriate.

  Here, since the hydraulic cylinder 10 and the lap arm portion 5 are linked to each other with the above-described configuration, when the lap arm portion 5 is rotated (operated), the hydraulic cylinder 10 is also rotated along with the rotation operation. Will be. Incidentally, the linkage mechanism between the hydraulic cylinder 10 and the lap arm portion 5 is not limited to the above-described configuration, and can be changed as appropriate. The lap arm unit 5 constitutes an operation unit according to the present invention.

Next, the internal structure of the hydraulic cylinder 10 will be described.
As shown in FIG. 5, the hydraulic cylinder 10 includes a cylinder tube 17 having a hollow cylindrical shape and containing hydraulic oil. Specifically, the cylinder tube 17 includes a cylindrical body portion 18 having both ends open, a head block 21 that is a lid, an annular sensor mounting port block 22, and a cap block 23 that is a lid. Has been.

  More specifically, a sensor attachment port block 22 having an internal pressure sensor attachment port 42 constituting an attachment hole is connected to the tip of the body portion 18. A head block 21 having a first port 41 constituting an oil passage is connected to the distal end side of the sensor mounting port block 22. On the other hand, a cap block 23 having a second port 43 constituting an oil passage is connected to the end of the body portion 18. With this configuration, an inner space where the cylinder tube 17 is filled with hydraulic oil is formed, and the inner space and the outside communicate with each other via the ports 41, 42, and 43.

  A disk-like piston portion 19 is slidably provided in the cylinder tube 17. Furthermore, the end of a rod-shaped piston rod 25 that penetrates the head block 21 is connected to the piston portion 19. On the other hand, a known tension chuck 26 (see FIGS. 1 and 2) is connected to the tip of the piston rod 25 so that a long workpiece W to be bent can be clamped. Yes. In this configuration, when the piston portion 19 slides back and forth in the cylinder tube 17, the piston rod 25 also moves back and forth, and the position of the tension chuck 26 changes back and forth (in the direction of the arrow in FIG. 1). Become. The tension chuck 26 constitutes a holding means according to the present invention.

  As shown in FIG. 3, a plurality of guide rods 48 parallel to the hydraulic cylinder 10 are provided around the hydraulic cylinder 10 described above. As a result, the support of the hydraulic cylinder 10 is reinforced, and the hydraulic cylinder 10 can be prevented from rotating around its axis.

  As shown in FIGS. 1 and 2, a workpiece holder 12 is attached to the center of the upper surface of the mold table 3. As shown in FIG. 2, the workpiece retainer 12 is for bringing the machining portion of the workpiece W held by the left and right tension chucks 26 into close contact with the mold surface 14 of the bending die 4. In other words, the workpiece holder 12 has a function of positioning the workpiece W at an appropriate position when machining is started.

  In the configuration described so far, when the lap arm portion 5 is rotated at a predetermined rotation angle and a predetermined rotation speed, the workpiece W is pulled through the hydraulic cylinder 10, and the workpiece W is bent. Bending is performed along the metal mold 4, and a series of molding processes is executed.

  Incidentally, as shown in FIG. 5, the inside of the hydraulic cylinder 10 is defined by a piston rod side pressure chamber 27 and a cap side pressure chamber 28 by the above-described piston portion 19. That is, the first port 41 and the internal pressure sensor mounting port 42 face the piston rod side pressure chamber 27, and the second port 43 faces the cap side pressure chamber 28.

  Further, as shown in FIG. 5, the stretch bender machine 1 includes a first port oil passage 32 that communicates with the first port 41 and a second port oil passage 33 that communicates with the second port 43. Yes. Furthermore, an electromagnetic proportional flow control valve 31 is disposed in the first port oil passage 32 and the second port oil passage 33. Further, a hydraulic oil supply device 34 is connected to the electromagnetic proportional flow control valve 31 via a hydraulic oil supply path 35. The hydraulic oil supply device 34 has a function of supplying hydraulic oil via the hydraulic oil supply path 35.

  Here, the electromagnetic proportional flow control valve 31 described above selects either the first port oil passage 32 or the second port oil passage 33 and supplies the hydraulic oil supplied from the hydraulic oil supply device 34. While ensuring a flow path, it has the function to adjust the flow volume of the hydraulic fluid. More specifically, when the electromagnetic proportional flow control valve 31 is driven in a predetermined manner and the oil passages 32 and 33 are switched, the hydraulic oil supply device 34 and the piston rod are switched via the first port 41 or the second port 43. The hydraulic oil can be supplied to the side pressure chamber 27 or the cap side pressure chamber 28. As the electromagnetic proportional flow control valve 31 and the hydraulic oil supply device 34, known products are preferably employed.

  The internal pressure sensor mounting port 42 is equipped with an internal pressure sensor 50 (see FIGS. 3 and 5) for measuring the internal pressure of the piston rod side pressure chamber 27. The internal pressure sensor 50 is provided with a measuring unit 51 at the tip of the outer casing, and the measuring unit 51 is disposed in the piston rod side pressure chamber 27. Measurement data measured by the internal pressure sensor 50 is transmitted to a cylinder internal pressure control device 45 described later. By the way, this internal pressure sensor 50 constitutes an internal pressure measuring means according to the present invention. As the internal pressure sensor 50, a known product made of a semiconductor or the like is preferably used.

Next, the cylinder internal pressure control device 45 of the stretch bender machine 1 will be described.
As shown in FIG. 5, the stretch bender machine 1 includes a cylinder internal pressure control device 45. The cylinder internal pressure control device 45 is connected to the electromagnetic proportional flow control valve 31, the hydraulic oil supply device 34, and the internal pressure sensor 50 so that signals can be transmitted and received. Specifically, the cylinder internal pressure control device 45 includes a substrate circuit (not shown), and a central control device (CPU) 46 is disposed on the substrate circuit. The central control device 46 executes a control process for driving control by transmitting drive signals to the electromagnetic proportional flow control valve 31 and the hydraulic oil supply device 34. In addition, a timer (TM) 47 is connected to the central controller 46 and has a function of starting time measurement at a predetermined measurement start timing and measuring the elapsed time at the predetermined measurement timing. For example, as will be described later, in this embodiment, it is possible to measure the elapsed time from the start of operation of the piston rod 25 and the lap arm portion 5 from the respective reference positions to the occurrence of abnormal pressure.

Next, the principal part which concerns on this invention is demonstrated.
As shown in FIG. 3, the stretch bender machine 1 includes a movement length detection device 54 that measures the movement length of the piston rod 25 associated with the hydraulic cylinder 10. As will be described later, the moving length detection device 54 includes a rotary encoder 55, a rack 57, and a pinion 56. More specifically, a long rack 57 is disposed along the longitudinal direction of the guide rod 48 around the guide rod 48 around the hydraulic cylinder 10 described above. On the other hand, a support plate 66 is disposed on the piston rod 25, and a support member 67 having a U-shaped cross section is connected to the support plate 66. A known rotary encoder 55 is attached to the support member 67. The rotary encoder 55 includes a rotatable shaft bar (not visible) that protrudes downward, and a pinion 56 that engages with the rack 57 is disposed at the tip of the shaft bar.

  In this configuration, when the piston rod 25 of the hydraulic cylinder 10 advances and retracts in the axial direction, the rotary encoder 55 also moves back and forth along the rack 57 in conjunction with this movement. If it does so, the pinion 56 engaged with the said rack 57 will rotate, and the rotary encoder 55 will detect the rotation amount. That is, the movement length (displacement value) in the axial direction of the piston rod 25 can be measured based on the rotation amount detected by the rotary encoder 55. Here, as shown in FIG. 5, the rotary encoder 55 is connected to the cylinder internal pressure control device 45 so as to be able to transmit and receive signals, and the measurement data of the rotary encoder 55 is transmitted to the cylinder internal pressure control device 45. It is configured to be transmitted.

  By the way, in this embodiment, the reference position of the piston rod 25 is set in advance before a series of molding processes. Then, the cylinder internal pressure control device 45 determines how much the piston rod 25 has moved from the reference position in the molding process based on the movement length measured by the rotary encoder 55 (operation displacement value (reference position) of the piston rod 25). The control content is detected as the movement length from Of course, the cylinder internal pressure control device 45 can also detect the fluctuation start timing, which is the timing when the piston rod 25 starts to fluctuate, by the movement length detection device 54.

  In the stretch bender machine 1, the rotary encoder 60 is also attached to the rotating shaft 16 of the lap arm unit 5. Specifically, as shown in FIG. 4, a rotatable shaft bar 61 of the rotary encoder 60 is fixed to the end of the rotating shaft 16, and when the rotating shaft 16 rotates, the rotating shaft 16 is interlocked with this. Thus, the shaft rod 61 rotates, and the rotation angle of the rotation shaft 16 can be detected by the rotary encoder 60. That is, with this configuration, the rotation angle (displacement value) of the lap arm portion 5 during the molding process is measured. As shown in FIG. 5, the rotary encoder 60 is also connected to the cylinder internal pressure control device 45, and measurement data of the rotary encoder 60 is transmitted to the cylinder internal pressure control device 45.

  In this embodiment, the reference position of the lap arm portion 5 is set in advance before a series of molding processes. Then, the cylinder internal pressure control device 45 determines how much the lap arm unit 5 has rotated from the reference position during the molding process based on the rotation angle measured by the rotary encoder 60 (reference displacement value (reference value)). The control content is detected as a rotation angle from the position. Of course, the cylinder internal pressure control device 45 can also detect a fluctuation start timing which is a timing when the lap arm unit 5 starts to fluctuate from the reference position.

  A commercially available monitor 65 (see FIG. 5) is connected to the cylinder internal pressure control device 45, and the moving length of the piston rod 25, the rotation angle of the lap arm portion 5, and the piston rod 25 or the lap arm portion. The elapsed time from the start of the operation No. 5 is displayed on the monitor 65 so that the operator can check the value. Specifically, a plurality of pieces of information can be confirmed by switching the screen display of the monitor 65. For example, as shown in FIG. 6, a graph can be displayed on the monitor 65 with the horizontal axis representing the operating time that is the elapsed time from the start of fluctuation of the piston rod 25 and the vertical axis representing the internal pressure of the piston rod side pressure chamber 27. it can. Further, as shown in FIG. 7, a graph in which the horizontal axis represents the moving length of the piston rod 25 from the reference position and the vertical axis represents the internal pressure of the piston rod side pressure chamber 27 can be displayed. Furthermore, as shown in FIG. 8, a graph in which the horizontal axis represents the rotation angle from the reference position of the lap arm portion 5 and the vertical axis represents the internal pressure of the piston rod side pressure chamber 27 can be displayed.

Next, the adjustment work of the stretch bender machine 1 will be described.
First, as shown in FIG. 2, both ends of the workpiece W are held by the tension chuck 26, and the processing portion is brought into close contact with the bending die 4. The position of the piston rod 25 and the position of the lap arm portion 5 in a state where the workpiece W is held are set as the reference positions described above.

  Next, the internal pressure of the piston rod side pressure chamber 27 is set to 5.0 MPa (reference internal pressure). At this time, a predetermined amount of hydraulic oil is supplied from the hydraulic oil supply device 34 to the piston rod side pressure chamber 27 or the cap side pressure chamber 28, and the internal pressure is appropriately adjusted. The internal pressure of the piston rod side pressure chamber 27 is measured by the internal pressure sensor 50 and can be confirmed by the monitor 65.

  And if the tension | tensile_strength state with which a reference | standard internal pressure is maintained is ensured, a series of shaping | molding processes will be performed. Specifically, the wrap arm 5 is started to rotate in a predetermined operation mode (rotation speed, rotation angle), and the workpiece W is bent along the bending die 4.

  Here, when the workpiece W is bent at a large angle, the tensile force generated by the hydraulic cylinder 10 rapidly increases, and the piston portion 19 advances rapidly in the cylinder tube 17. Then, the piston rod side pressure chamber 27 is rapidly increased in pressure (for example, 5.1 MPa) as compared with the reference internal pressure, and an abnormal pressure is generated in the piston rod side pressure chamber 27.

  At this time, the operator can grasp the occurrence of abnormal pressure from the graph displayed (notified) on the monitor 65. That is, the cylinder internal pressure control device 45 displays on the monitor 65 that the piston rod side pressure chamber 27 has become a high pressure (5.1 MPa) based on the measurement data transmitted from the internal pressure sensor 50. Further, the operator can display the operation time at the time when the abnormal pressure is generated, the moving length of the piston rod 25 from the reference position, or the reference position of the lap arm unit 5 on the screen display of the monitor 65 (see FIGS. 6 to 8). The rotation angle from can be confirmed.

  For example, according to the screen display shown in FIG. 6, it can be confirmed that an abnormal pressure has occurred when the operation time of the lap arm portion 5 is 71 seconds. Further, according to the screen display shown in FIG. 7, it can be confirmed that an abnormal pressure is generated when the piston rod 25 is moved by 90 mm from the reference position. Further, according to the screen display shown in FIG. 8, it can be confirmed that an abnormal pressure has occurred when the lap arm portion 5 is rotated by 60 degrees from the reference position.

  Then, the operator corrects the tensile force of the hydraulic cylinder 10, the rotation angle of the lap arm portion 5, the rotation speed of the lap arm portion, and the like based on the information confirmed on the monitor 65, thereby obtaining a desired bent product. The adjustment work is performed sequentially.

  Note that the display mode of the monitor 65 described above continuously monitors the operation displacement of the piston rod 25 and the lap arm portion 5 from the start of processing, displays the graph, and displays the operation displacement value and the operation time when abnormal pressure occurs. Although it is a structure, it is good also as a structure which displays only the operation | movement displacement and operation | movement time at the moment when abnormal pressure generate | occur | produced. That is, the present invention is characterized in that at least an operation displacement and an operation time when an abnormal pressure is generated are notified.

  A moving length detector 54 that measures the moving length of the piston rod 25, a rotary encoder 60 that measures the rotation angle of the lap arm unit 5, and a cylinder internal pressure control that detects the operation displacement value by executing the above control contents. The device 45 constitutes a motion displacement value detecting means according to the present invention.

  Further, when the abnormal pressure is detected, the cylinder internal pressure control device 45 that executes the control content for notifying the operation displacement value by the monitor 65 constitutes the operation displacement value notification means according to the present invention.

  The timer 47 for measuring time and the cylinder internal pressure control device 45 for executing the control content for calculating the operation time constitute an operation time measuring means according to the present invention.

  Further, the operation time notifying unit according to the present invention is constituted by the cylinder internal pressure control device 45 that executes the control content for notifying the operation time by the monitor 65 when the abnormal pressure is detected.

  In addition to the above configuration, the operation speed may be calculated from the detected operation time and operation displacement value and displayed on the monitor 65. Moreover, it is good also as a structure which digitizes and displays a numerical value other than the display mode graphed like FIGS. 6-8.

  The above configuration is a configuration in which the rotary encoders 55 and 60 for detecting the operation displacement value are arranged on the piston rod 25 and the lap arm unit 5, but the rotary encoders 55 and 60 are arranged on the piston rod 25 or the lap arm unit 5. An arrangement may be adopted.

1 is a side view of a stretch bender machine 1. FIG. 1 is a plan view of a stretch bender machine 1. FIG. 1 is an enlarged perspective view showing a hydraulic cylinder 10. FIG. 2 is a conceptual diagram showing a rotary encoder 60. FIG. It is explanatory drawing explaining the internal structure of the hydraulic cylinder 10, and the control circuit of the stretch bender machine 1. FIG. It is explanatory drawing which shows the display content of the monitor. It is explanatory drawing which shows the display content of the monitor. It is explanatory drawing which shows the display content of the monitor.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Stretch-bender machine 4 Bending die 5 Lap arm part 9 Piston part 10 Hydraulic cylinder 17 Cylinder tube 25 Piston rod 26 Tension chuck 27 Piston rod side pressure chamber 28 Cap side pressure chamber 45 Cylinder internal pressure control device 47 Timer 50 Internal pressure sensor 51 Measuring Unit 54 Moving Length Detection Device 60 Rotary Encoder 65 Monitor W Workpiece

Claims (3)

A hollow cylinder tube into which hydraulic oil is introduced, a piston portion slidably disposed in the cylinder tube, the piston portion connected to the end, and disposed in a mold of a predetermined shape at the tip A hydraulic cylinder comprising a rod-like piston rod to which holding means for holding a long workpiece is connected, and a piston rod-side pressure chamber and a cap-side pressure chamber defined in the cylinder tube by the piston portion A cylinder,
With an operating part linked to a hydraulic cylinder,
In the stretch bender machine that performs a series of molding processes for pulling the workpiece through a hydraulic cylinder and bending the workpiece along the mold by the operation unit operating in a predetermined mode.
An internal pressure measuring means for measuring the internal pressure of the piston rod side pressure chamber;
An operation displacement value detecting means for detecting an operation displacement value that is a displacement value from a predetermined reference position of the piston rod and / or the operation unit;
When the internal pressure measuring means measures an internal pressure higher than a predetermined reference internal pressure during the molding process, it is provided with an operation displacement value notifying means for notifying an operation displacement value of the piston rod and / or the operation portion at that time. Stretch bender machine characterized by An operation time measuring means for measuring an operation time which is an elapsed time from a timing at which the piston rod and / or the operation unit starts to operate from a predetermined reference position;
When the internal pressure measuring means measures an internal pressure higher than a predetermined reference internal pressure during molding, it is provided with an operating time notifying means for notifying the operating time of the piston rod and / or the operating portion at that time. The stretch bender machine according to claim 1. The internal pressure measuring means is
The stretch bender machine according to claim 1, further comprising a measurement unit, wherein the measurement unit is disposed in the piston rod side pressure chamber.

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