Patent Application
20110061431
The present invention relates to a method of bending a plate and a bending angle detection apparatus, and more particularly to a method of bending a plate and bending angle detection apparatus in which labor required for a work of bending a plate can be reduced.
Patent Literature 1 discloses an apparatus for bending a strip material. The apparatus comprises a stationary die having a slit, and a movable die which is rotatably fitted onto a shaft body of the stationary die.
According to the invention disclosed in Patent Literature 1, the parallelism of a pair of opposing pressing die portions of the movable die is not impaired during a bending process, and only the shaft body can be easily replaced without disassembling gears of a rotation transmission mechanism, and the movable die.
Patent Literature 2 discloses a method of bending a plate. In the method, a plate is fed out from an outlet, and, during when the feeding of the plate is stopped, the plate is pressed against an end portion of the outlet side, thereby bending the plate.
According to the invention disclosed in Patent Literature 2, even an unskilled person can bend easily and rapidly a plate into a desired shape in a similar manner as a skilled person.
Patent Literature 3 discloses a method of bending a plate. In the method, the below-described two steps are repeated. In the first step, a feed bearing is contacted with a plate. In the second step, while the plate is intermittently fed out through a slit formed in a stationary die, each time when the feeding of the plate is stopped by a stop of operation of a servomotor, the plate is pressed by a pressing member against an outlet corner portion of the slit, thereby being a plate.
According to the invention disclosed in Patent Literature 3, when a plurality of places of a plate such as a blade member are automatically bent in a sequential manner, the plurality of bent places can be accurately determined.
Patent Literature 4 discloses an apparatus for processing a plate. The apparatus comprises a bending process shape inputting unit, a characteristic data inputting unit, and a calculating unit. The bending process shape inputting unit receives an input of a geometric bending process shape of a long plate. The characteristic data inputting unit receives characteristic data related to a process of bending the plate. The calculating unit calculates bending data of the plate based on the geometric bending process shape which is received by the bending process shape inputting unit, and the characteristic data which are received by the characteristic data inputting unit.
According to the invention disclosed in Patent Literature 4, characteristics related to the process of bending the plate are considered, whereby the plate can be accurately processed.
In the inventions disclosed in Patent Literatures 1 to 3, however, there is a problem in that it is difficult to bent a plate to an angle desired by the user, because, when a force is applied in order to bend a plate and thereafter the force is cancelled, springback occurs and the angle of the bent portion is varied. The term “springback” means a phenomenon that, when a force is applied to a plate at a degree by which plastic deformation occurs and thereafter the force is removed from the plate, deformation due to elastic deformation is eliminated from deformation of the plate. It is difficult to estimate the degree by which the angle of the bent plate is varied by springback.
In the invention disclosed in Patent Literature 4, a long plate can be accurately processed, but there is a problem in that it is difficult to obtain characteristic data required in the process. Usually, characteristic data are produced from data of the degree by which a plate is bent in a bending process, and a result of a measurement of the angle of a portion which is bent by the bending process. When the characteristic data are produced in this way, it is necessary to process the data after the bending process and the measurement of a sample produced by the process are repeated. The work requires a prolonged time period and much labor. The work increases the labor and required time period of the whole bending process.
The invention has been conducted in order to solve the above-discussed problems. It is an object of the invention to provide a method of bending a plate and bending angle detection apparatus in which labor required for a work of bending a plate can be reduced.
In order to attain the object, according to a certain aspect of the invention, the method of bending a plate is a method of bending a plate by a bending machine. In the method of bending a plate, a work of bending the plate is repeated a plurality of times until it is detected that an angle of a bent portion of the plate reaches a predetermined angle, in a state where the plate is attached to the bending machine and springback is completed.
The work of bending the plate is repeated a plurality of times until it is detected that the angle of the bent portion of the plate reaches the predetermined angle, in a state where the plate is attached to the bending machine and springback is completed. Therefore, it is not necessary to remove the plate and measure the angle of the bent portion. It is not necessary also to consider springback. As a result, labor required for the work of bending the plate can be reduced.
Furthermore, preferably, the above-described method of bending a plate is a method in which the plate is further bent until a bending angle detection apparatus connected to the bending machine detects it.
Furthermore, preferably, the above-described bending angle detection apparatus is contacted with the plate to measure a direction of the plate before the bending machine bends the plate, and a direction of the plate after the bending machine bends the plate.
According to another aspect of the invention, the bending angle detection apparatus detects an angle. The bending angle detection apparatus is an apparatus which is connected to a bending machine. The angle is an angle of a bent portion of a plate which is bent by the bending machine. The bending angle detection apparatus comprises a signal production device, a connecting portion, a drive device, and a rotation angle detection device. The signal production device produces a signal corresponding to whether the apparatus is contacted with the plate or not. The connecting portion rotatably connects the signal production device to the bending machine. The drive device drives the signal production device so that the signal production device is rotated. The rotation angle detection device detects a rotation angle of the signal production device. The connecting portion has a holder which is fixed to the bending machine, and bearings which are connected to the holder. The bearing rotatably positions the signal production device so that, when the bending machine bends the plate, the rotation axis of the plate coincides with that of the signal production device.
By the connecting portion, the signal production device is rotatably connected to the bending machine so that a rotation axis of the plate in the case where the bending machine bends the plate coincides with that of a rotation member. Furthermore, the signal production device is driven by the drive device so that the signal production device is rotated. The rotation angle of the signal production device is detected by the rotation angle detection device. Therefore, the rotation angle of the signal production device coincides with that of the plate which is bent by the bending machine. The signal production device produces the signal corresponding to whether the apparatus is contacted with the plate or not. When the rotation angle detection device detects the rotation angle of the signal production device at the time when the signal is produced, therefore, it is possible to detect the rotation angle of the plate which is bent by the bending machine, without detaching the plate from the bending machine. When the rotation angle of the plate is measured in a state where springback is completed, it is not required to consider an error due to springback. As a result, labor required for the work of bending the plate can be reduced.
In the method of bending a plate and bending angle detection apparatus of the invention, labor required for a work of bending a plate can be reduced.
Hereinafter, an embodiment of the invention will be described with reference to the drawings. The foregoing summary of the invention and the following detailed description of the preferred embodiment of the invention are better understood when read in conjunction with the accompanying drawings. For the purpose of illustrating the invention, the drawings depict the present preferred embodiment. In the following description, the identical components are denoted by the same reference numerals, and also their names and functions are identical. Therefore, they will not be described repeatedly in detail.
The bending angle detection apparatus 50 of the embodiment is attached to the bending machine 80. The bending angle detection apparatus 50 is connected to the bending machine 80, and measures the angle of a plate which is bent by the bending machine 80. The bending machine 80 will be described later.
The bending angle detection apparatus 50 of the embodiment comprises the servomotor 60, the holder 62, the sensor ring L 64, the sensor ring R 66, spacers 68, and bearings 70.
The servomotor 60 is controlled by a controlling portion 98 of the bending machine 80 which will be described later. The servomotor 60 drives the sensor ring L 64 and the sensor ring R 66. The servomotor 60, the sensor ring L 64, and the sensor ring R 66 are attached to the holder 62. The tip end of the bending shaft 92 of the bending machine 80 is fitted into the holder 62. The bending shaft 92 is passed through the rotary cylinder 90 which is similarly a component of the bending machine 80, and then fitted into the holder 62. The sensor ring L 64 measures the angle of the bent portion of the blade member plate 300, from one side face of the blade member plate 300. The sensor ring R 66 measures the angle of the bent portion of the blade member plate 300, from the side face opposite to the sensor ring L 64. The spacers 68 are members for maintaining the bearings 70 to adequate positions. The bearings 70 are members for rotatably positioning the sensor ring L 64 and the sensor ring R 66 so that, when the blade member plate 300 is bent by the bending machine 80, the rotation axis of the blade member plate 300 coincides with the rotation axes of the sensor ring L 64 and the sensor ring R 66. The spacers 68 and the bearings 70 are connected to the holder 62 by bolts 72.
The servomotor 60 will be described with reference to
The structure of the spring joint 104 will be described with reference to
The rotor of the motor body 100 is fitted into the upper rotary cylinder 110. The upper rotary cylinder 110 transmits the torque produced by the motor body 100 to the middle rotary cylinder 114. A projection 130 is disposed on the lower end of the upper rotary cylinder 110. The first spring 112 is fitted to the upper rotary cylinder 110 and the middle rotary cylinder 114, and, when the upper rotary cylinder 110 cannot directly transmit the torque to the middle rotary cylinder 114, transmits the torque produced by the motor body 100 to the middle rotary cylinder 114. The middle rotary cylinder 114 is fitted into the upper rotary cylinder 110 and the lower rotary cylinder 118 while being passed through the first spring 112 and the second spring 116. The middle rotary cylinder 114 transmits the torque which is transmitted by the upper rotary cylinder 110 or the first spring 112, to the second spring 116. A projection 132 is disposed on a middle portion of the middle rotary cylinder 114. The second spring 116 is fitted to the middle rotary cylinder 114 and the lower rotary cylinder 118, and, when the middle rotary cylinder 114 cannot directly transmit the torque to the lower rotary cylinder 118, transmits the torque produced by the motor body 100 to the lower rotary cylinder 118. The rotation shafts of the first gear 106 and the second gear 108 are fitted into the lower rotary cylinder 118. The lower rotary cylinder 118 transmits the torque produced by the motor body 100 to the rotation shafts of the first gear 106 and the second gear 108. A projection 134 is disposed on the upper end of the lower rotary cylinder 118.
The operation of the spring joint 104 will be described with reference to
By contrast, it is assumed that a torque which is counterclockwise as viewed from the motor body 100 is transmitted to the spring joint 104. At this time, the upper rotary cylinder 110 is rotated in the same direction as the rotor of the motor body 100. However, the projection 130 of the upper rotary cylinder 110 does not push the projection 132 of the middle rotary cylinder 114. The torque produced by the motor body 100 is transmitted to the middle rotary cylinder 114 by the first spring 112. In this case, however, the first spring 112 is deformed, and hence the torque transmitted to the middle rotary cylinder 114 is not so large. When a resistance is applied to the lower rotary cylinder 118 for any reason, the resistance is applied also to the middle rotary cylinder 114 through the projection 132 and the projection 134, and hence the middle rotary cylinder 114 is not rotated.
The structure of the holder 62 will be described with reference to
The configuration of the sensor ring L 64 will be described with reference to
The configuration of the sensor ring R 66 will be described with reference to
The placement of the sensor ring L 64 and other components will be described with reference to
At this time, the gear 154 of the sensor ring L 64 meshes with the first gear 106, and the gear 164 of the sensor ring R 66 meshes with the second gear 108. According to the configuration, the torque produced by the motor body 100 of the servomotor 60 is transmitted to the sensor ring L 64 and the sensor ring R 66.
The position where the sensor ring L 64 is fixed is different from that where the sensor ring R 66 is fixed. Since they are different from each other, the rotation axis 170 of the sensor ring L 64 is different from the rotation axis 172 of the sensor ring R 66. The rotation axis 170 and the rotation axis 172 are located in the vicinity of an edge of the blade member plate 300 which is bent by the rotary cylinder 90. More specifically, the rotation axis 170 is placed so as to coincide with the rotation axis when the blade member plate 300 is bent toward one side by the rotary cylinder 90, and the rotation axis 172 is placed so as to coincide with the rotation axis when the blade member plate 300 is bent toward the other side. Since the rotation axis 170 and the rotation axis 172 coincide with the rotation axis when the blade member plate 300 is bent, the rotation angle of the sensor ring L 64 or the sensor ring R 66 coincides with the bending angle of the plate. In many cases, the rotation axis when the blade member plate 300 is bent is located at a distance which is equal to one half of the thickness of the blade member plate 300, from the tip end of the claw of the rotary cylinder 90, and at a distance which is equal to one half of the thickness of the blade member plate 300, from the side face thereof.
The manner of the attachment of the bending angle detection apparatus 50 will be described with reference to
The bending machine 80 further comprises a touch panel 91 and a cylinder rotation motor 93. The touch panel 91 is a device which displays information, and through which the user inputs information. The cylinder rotation motor 93 drives the rotary cylinder 90.
The controlling portion 98 of the bending machine 80 will be described with reference to
The cylinder rotation motor I/O 180 outputs a control signal to the cylinder rotation motor 93. The first external I/O 182 is connected to the servomotor 60, receives an input of information indicative of the rotation angle from the rotation angle sensor 102, and outputs a control signal to the motor body 100. The second external I/O 184 receives a signal input by the microswitch L 152. The third external I/O 186 receives a signal input by the microswitch R 162. The touch panel I/O 188 outputs an image signal to the touch panel 91, and receives an input of information by the user through the touch panel 91. The flash memory reading device 190 reads control programs which are to be executed by the CPU 196, from a flash memory 350. The control programs are used for performing not only the process of bending the blade member plate 300 but also the control on the bending angle detection apparatus 50. The ROM 192 stores programs for reading the control programs from the flash memory 350, and executing them. The RAM 194 temporarily stores the control programs read from the flash memory 350. Furthermore, the RAM 194 temporarily stores data for enabling the CPU 196 to process information. The CPU 196 sequentially executes the control programs stored in the RAM 194, thereby controlling the process of bending the blade member plate 300 and the angle measurement by the bending angle detection apparatus 50.
The procedure of measuring the angle of the blade member plate 300 in the bending angle detection apparatus 50 of the embodiment will be described with reference to
It is assumed that the sector plate 156 and the protrusion 166 are placed in a state where they contact with each other, at a position which is opposite to the servomotor 60 with respect to the bending shaft 92. In the embodiment, the positions of the sensor ring L 64 and the sensor ring R 66 at this time are referred to as “reference position”. In this state, feed rollers (not shown) of the bending machine 80 feed the blade member plate 300 through the slit of the bending shaft 92.
When the blade member plate 300 is fed, the controlling portion 98 outputs the control signal to the cylinder rotation motor 93 through the cylinder rotation motor I/O 180, thereby driving the cylinder rotation motor 93. Therefore, the rotary cylinder 90 is rotated, and the tip end of the claw reaches the bending start position.
When the tip end of the claw of the rotary cylinder 90 reaches the bending start position, the servomotor 60 produces a torque in accordance with the control of the controlling portion 98. The torque is transmitted to the sensor ring L 64 and the sensor ring R 66 through the first gear 106 and the second gear 108. Therefore, the sensor ring R 66 is rotated. The sensor ring L 64 is rotated at first, but the rotation is stopped in mid-course because, as shown in
When the rotation angle of the microswitch R 162 is detected, the controlling portion 98 causes the cylinder rotation motor 93 to drive. Therefore, the rotary cylinder 90 is rotated, and the tip end of the claw of the rotary cylinder 90 bends the blade member plate 300.
When the blade member plate 300 is bent, the servomotor 60 produces a torque in accordance with the control of the controlling portion 98. The torque is transmitted to the sensor ring R 66 through the second gear 108. Therefore, the microswitch R 162 is again rotated. When again contacted with the blade member plate 300, the microswitch R 162 again inputs the signal into the third external I/O 186.
When the angle difference is calculated, the servomotor 60 produces a torque in accordance with the control of the controlling portion 98. The torque is transmitted to the sensor ring R 66 through the second gear 108. Therefore, the microswitch R 162 is again rotated. As a result of the rotation, the microswitch R 162 is returned to the reference position. When returned to the reference position, the protrusion 166 pushes the sector plate 156. Therefore, the gear 154 again meshes with the first gear 106.
The control procedure for accurately bending the blade member plate 300 without previously measuring springback will be described with reference to
In step S250, the CPU 196 of the bending machine 80 causes the feed rollers which are not shown, to drive to feed the blade member plate 300 by a predetermined length.
In step S252, the CPU 196 outputs a control signal for producing a torque, to the servomotor 60. The servomotor 60 produces a torque in accordance with the control signal. When the torque produced by the servomotor 60 is transmitted, the sensor ring R 66 is rotated. In this case, one of the sensor ring L 64 is rotated at first, and then does not mesh with the first gear 106, so that the sensor ring is not rotated finally.
In step S254, the CPU 196 determines whether the sensor ring R 66 detects the blade member plate 300 or not, based on the signal which is input to the third external I/O 186 by the microswitch R 162. If it is determined that the blade member plate 300 is detected (YES in step S254), the process is transferred to step S256. If not (NO in step S254), the process is transferred to step S252.
In step S256, the CPU 196 outputs a control signal for stopping the production of a torque, to the servomotor 60. Therefore, the rotations of the first gear 106 and the second gear 108 are stopped.
In step 5258, the CPU 196 calculates the rotation angle of the sensor ring R 66 based on the rotation angle data which are input by the rotation angle sensor 102. When the rotation angle of the sensor ring R 66 is calculated, the CPU 196 stores the rotation angle in the RAM 194. The rotation angle indicates the starting point of the process of bending the blade member plate 300.
In step 5260, the CPU 196 the CPU 196 outputs a control signal for producing a torque, to the servomotor 60. When the control signal is input, the rotor of the motor body 100 rotates. In the embodiment, the rotation angle at this time is an angle satisfying the following requirement. The requirement is that the angle of the bent portion of the blade member plate 300 equal to an angle which is designated by the user through the touch panel 91. In accordance with the rotation of the rotor, the sensor ring R 66 tries to rotate. However, the sensor ring is blocked by the blade member plate 300, and hence the sensor ring R 66 does not rotate. Therefore, the upper rotary cylinder 110 of the spring joint 104 is relatively rotated with respect to the lower rotary cylinder 118.
In step S262, the CPU 196 causes the cylinder rotation motor 93 to drive. Therefore, the rotary cylinder 90 is rotated, and the blade member plate 300 is bent in the direction in which it is separated from the microswitch R 162. At this time, the first spring 112 and second spring 116 of the spring joint 104 are returned from the state where the springs are elastically deformed, to that where the springs are not elastically deformed. Therefore, the microswitch R 162 tracks the blade member plate 300.
In step S264, based on the signal which is input by the microswitch R 162, the CPU 196 determines whether the microswitch R 162 becomes not to detect the blade member plate 300 or not. If it is determined that the microswitch becomes not to detect the blade member plate 300 (YES in step S264), the process is transferred step to S266. If not (NO in step S264), the process is transferred to step S262.
In step 5266, the CPU 196 again causes the cylinder rotation motor 93 to drive. This causes the rotary cylinder 90 to be further rotated, and the blade member plate 300 is further bent. Namely, the blade member plate 300 is further pressed. The rotation angle of the rotary cylinder 90 is an angle at which the elastic deformation of the blade member plate 300 slightly advances. Thereafter, the CPU 196 causes the cylinder rotation motor 93 to reversely rotate. Because of the reverse rotation of the cylinder rotation motor 93, the rotation angle of the rotary cylinder 90 is returned to the angle at the timing when the microswitch R 162 becomes not to detect the blade member plate 300 as a result of the rotation of the rotary cylinder 90 in step S262. At this time, the direction of the blade member plate 300 is slightly returned by springback, but is not returned in the direction before the further pressing because of advancement of the elastic deformation. As a result, the angle of the blade member plate 300 when the claw of the rotary cylinder 90 is separated approaches the angle which is designated by the user.
In step 5268, based on the signal which is input by the microswitch R 162, the CPU 196 determines whether the microswitch R 162 becomes not to detect the blade member plate 300 or not. If it is determined that the microswitch becomes not to detect the blade member plate 300 (YES in step S268), the process is transferred to step S270. If not (NO in step S288), the process is transferred to step 5266.
In step 5270, the CPU 196 causes the servomotor 60 to drive so that the microswitch R 162 is returned to the reference position.
In step 5272, the controlling portion 98 updates information in order to perform the next bending process.
As described above, the bending machine 80 in the embodiment accurately bends the blade member plate 300 based on the direction of the blade member plate 300 which is detected by the bending angle detection apparatus 50 as a result of the angle measurement. Springback is not measured. Therefore, the user of the bending machine 80 is not required to manually measure springback each time. To begin with, it becomes unnecessary to know in detail what extent of rotating of the rotary cylinder 90 corresponds to accurate bending of the blade member plate 300. Therefore, labor required for the work of bending the blade member plate 300 can be correspondingly reduced.
All points of the disclosed embodiment are exemplifications. The scope of the invention is not limited based on the above-described embodiment. It is a matter of course that various design changes may be made without departing the spirit of the invention.
For example, the spring joint 104 is not limited to the above-described configuration. In place of the above-described spring joint 104, a plate spring or a rubber-made cylinder may be used which transmits the torque supplied by the motor body 100 of the servomotor 60 to the signal production device, and which is elastically deformed by the torque. In place of the spring joint 104, another buffer member may be used. In the case where a buffer member is used, the buffer member is requested to transmit the torque supplied by the motor body 100 to the sensor ring L 64 or the sensor ring R 66, and to be elastically deformed by the torque supplied by the motor body 100. The spring joint 104 may be omitted.
In place of the configuration in which the rotation angles of the sensor ring L 64 and the sensor ring R 66 are indirectly measured by the rotation angle sensor 102, the rotation angles may be directly measured. A specific measure for directly measuring the rotation angles, a method may be employed in which a spur gear meshes with the gear 154 of the sensor ring L 64 and the gear 164 of the sensor ring R 66, and an angle sensor is connected to its shaft.
In place of the servomotor 60, another drive device may drive the sensor ring L 64 and the sensor ring R 66. The mechanism for the driving is particularly limited.
In place of the sensor ring L 64 and the sensor ring R 66, a signal production device which produces a signal corresponding to whether the apparatus is contacted with the blade member plate 300 or not, in a mechanism that is different from the rings may be disposed in the bending angle detection apparatus 50. As an example of such a signal production device, there is a device in which a microswitch is caused to linearly run, and its rotation angle is calculated based on the positional relationship between the position where the microswitch is contacted with the blade member plate 300, and the position of the rotation axis of the blade member plate 300 that is bent.
The bending angle detection apparatus 50 may comprise a controlling portion. In this case, the controlling portion may be configured in a similar manner as the controlling portion 98. According to the configuration, the bending angle detection apparatus 50 can measure the angle of the bent portion of the blade member plate 300 without depending on the controlling portion 98 of the bending machine 80. In the case where springback is to be measured, the controlling portion of the bending angle detection apparatus 50 may cooperate with the controlling portion 98 of the bending machine 80.
The program recording medium from which the controlling portion 98 reads control programs is not limited to the flash memory 350. For example, the medium may be a USB memory. Alternatively, control programs may be received via the Internet.
| Filing Document | Filing Date | Country | Kind | 371c Date |
|---|---|---|---|---|
| PCT/JP2008/059208 | 5/20/2008 | WO | 00 | 11/17/2010 |
