Control device for a molded article take-out machine

Abstract

The present invention provides a control device of a molded product take-out machine, which performs appropriate action when a collision occurs while a servo system control section is manually operated. If a collision detection section (19) outputs an action stop command, a deviation clearing section (21) performs a clearing action that makes the deviation of the servo system control section 0 while maintaining the open state of the servo system control section. The positioning is completed by the deviation becoming 0, so that operation can be performed again. When a retreat operation is performed after the action is stopped, the servo motor (9) is operated as per the operation command, so that retreat can be smoothly performed from the collision state.

Description

TECHNICAL FIELD

[0001] The present application relates to a control device of a molded product take-out machine capable of performing appropriate retreat operation when a collision occurs during manual operation. BACKGROUND

[0002] In Japanese Patent No. 3526555 (Patent Document 1), there is disclosed an invention of a molded product take-out machine capable of preventing deformation of a member on which a chuck portion is mounted and preventing damage of a molded product even when excessive external force is applied to the chuck portion. In this invention, when the chuck portion is moved to a given position, the electric motor is subjected to direct current restraint to stop the chuck portion from being held at the given position, and a collision detection sensor is used to detect a case where external force is applied to the stopped and held chuck portion, and a direct current restraint force based on the electric motor is subjected to reduction control to allow the chuck portion to be moved by the external force.

[0003] PRIOR ART DOCUMENTS

[0004] PATENT DOCUMENTS

[0005] Patent Document 1: Japanese Patent No. 3526555

[0006] However, it is difficult in reality to install a collision detection dedicated sensor and a collision retreat dedicated sensor in the entire frame of a take-out head including the take-out machine, and this also causes a large increase in cost. In addition, depending on the work environment and the work condition, it is difficult to predict with which part a collision occurs. Therefore, in practice, an operator sometimes erroneously performs operation in manual operation of the molded product take-out machine to cause the take-out head to collide with a mold and a peripheral device (a peripheral object), and the take-out head, a track roller as a guide portion, and a fixing plate are damaged due to the subsequent retreat operation. SUMMARY

[0007] An object of the present application is to provide a control device of a molded product take-out machine capable of performing appropriate operation for preventing damage when a collision occurs during manual operation of the molded product take-out machine.

[0008] The present application takes as an object of improvement a control device for a molded product take-out machine that includes a servo system control section that detects the position and speed of a drive section of a servo motor that drives a frame with a take-out head in the molded product take-out machine using an encoder, calculates the deviation of the detected value of the position from the value of a position command and the deviation of the detected value of the speed from the value of a speed command, and controls the servo motor by feedback control of the position and speed of the drive section based on these deviations, and a manual command generation section that generates a manual command when the servo system control section is manually operated. The control device of the present application includes a torque detection section, a collision detection section, and a deviation elimination section in order to enable proper operation in the event of a collision. The torque detection section detects the torque applied to the frame when the servo motor is manually operated by providing an operation command to the servo system control section from the manual command generation section. Moreover, the collision detection section outputs an operation stop command when the take-out head collides with a surrounding object when the detected value of the torque detection section becomes greater than a predetermined value. On this basis, the deviation elimination section performs an elimination operation that sets the deviation of the servo system control section to zero while maintaining the open state of the servo system control section when the operation stop command is output.

[0009] Under the current situation, when the take-out head of the upper and lower frames collides with a mold or the like in manual operation and the motor torque value reaches, for example, 300%, an overload error is generated and the servo motor is stopped. At this time, since the servo system control section becomes in a servo-off state, in order to retreat from the collision state, it is necessary to again make the servo system control section servo-on. If the servo system control section becomes servo-off, the position deviation becomes zero and the take-out head slightly descends in the state of contact with the mold or the like, and there is a concern that the take-out head will be damaged. Furthermore, when performing the retreat operation, if the manual operation is mistaken when made servo-on, the take-out head collides with the mold again or a load is applied, and thus it is possible that the upper and lower frames and the take-out head will be deformed. Furthermore, depending on the situation, it is possible that the servo system control section will again become servo-off and cannot be separated from the collision state.

[0010] According to the present application, if the operation stop command is output, the deviation elimination section performs an elimination operation that sets the deviation of the servo system control section to zero while maintaining the open state of the servo system control section, and thus the positioning is determined to be complete by the deviation becoming zero and operation can be performed again. As a result, when performing the retreat operation after the operation stop, the servo motor can be operated as instructed by the operation command, the upper and lower frames and the take-out head can be moved, and retreat from the collision state can be performed smoothly.

[0011] Preferably, the collision detecting section sets the aforementioned predetermined value to a value lower than the limit value at the time of automatic operation. Thus, it is possible to prevent the load on the surrounding object at the time of collision from becoming necessary or more due to differences in manual operation by the operator.

[0012] Further, preferably, the collision detecting section outputs an alarm signal at substantially the same time as the output of the operation stop command, and continues to output the alarm signal until a given time elapses after the detection value of the torque detecting section becomes lower than the aforementioned predetermined value again when a movement command is inputted from the manual command generating section to the servo system control section after the retreat from the collision, and the detection value of the torque detecting section becomes lower than the aforementioned predetermined value. If the alarm is eliminated at substantially the same time as the detection value of the torque detecting section becomes lower than the aforementioned predetermined value, it is possible that the retreat from the collision state is not completed in the case where the manual operation by the operator is stopped at substantially the same time. Thus, by the output of the alarm signal until a given time elapses, the operator can continue the manual operation, and retreat completely from the collision state.

[0013] Further, preferably, the collision detecting section outputs an alarm signal at substantially the same time as the output of the operation stop command, and continues to output the alarm signal until a given time elapses after the retreat from the collision, and the detection value of the torque detecting section becomes lower than the aforementioned predetermined value again when a movement command is inputted from the manual command generating section to the servo system control section. If the alarm is eliminated at substantially the same time as the detection value of the torque detecting section becomes lower than the aforementioned predetermined value, it is possible that the retreat from the collision state is not completed in the case where the manual operation by the operator is stopped at substantially the same time. Thus, by the output of the alarm signal until a given time elapses, the operator can continue the manual operation, and retreat completely from the collision state.

[0014] Further, preferably, the deviation eliminating section performs the eliminating operation again when a movement command is inputted from the manual command generating section. If so, it is possible to reliably eliminate the deviation data before the retreat operation is performed. Further, the movement command is not inputted in a state where a slight deviation remains, and thus it is possible to prevent the risk of a re-collision due to the feedback control that sharply makes the slight deviation zero, with an operation accompanied by an overshoot or an undershoot.

[0015] Preferably, the torque detecting section is configured to be able to detect the direction of action of at least one torque acting on the extraction head, and the display section of the input section for performing the manual operation displays the direction of action of the torque and a torque display proportional to the magnitude of the torque. These torque displays can be any of numerical value display, bar graph display, meter display, and the like. If so, the operator can correctly decide in which direction the torque is to be reduced to retreat well in the case where the retreat operation is performed, based on the data.

[0016] Preferably, the display section displays a prompt display that prompts the retreat direction adjacent to the torque display. The prompt can be any of character display, mark display, and lamp display, and the like. If such a display is performed, even an unskilled person can easily perform the retreat operation after the collision.

[0017] In addition, preferably, the torque detection section is configured to be able to detect the torque in the lateral direction, the torque in the pulling direction, and the torque in the up-down direction, in the case where the servo motor is used for driving in the 3-axis (XVZ) direction. Further, preferably, in the case where the number of axes driven by the servo motor is 5-axis, 6-axis, or the like, the torque detection section is configured to be able to detect the torque of all of the multi-axes. Furthermore, preferably, in the case where the take-out head is equipped in the posture control device, the torque applied to the take-out head from the posture control device is also detected by the torque detection section.

[0018] It is also possible to show three prompting displays that prompt the evacuation direction, respectively, adjacent to the three torque displays in the display section. If such display is performed, the operator is able to correctly decide in which direction to evacuate to reduce the torque based on the data in the case where the evacuation action after the collision is performed. BRIEF DESCRIPTION OF DRAWINGS

[0019] Figure 1 is a block diagram showing the schematic structure of a take-out machine of a molded article to which one embodiment of the present application is applied.

[0020] Figure 2 is a timing chart before and after collision detection of the present embodiment.

[0021] Figure 3 is a diagram showing one example of the display of the input section.

[0022] Figure 4 is an actual action flowchart at the time of collision detection.

[0023] Figure 5 is an actual action flowchart at the time of collision evacuation.

[0024] BRIEF DESCRIPTION OF DRAWINGS

[0025] 1: take-out machine of a molded article

[0026] 3: take-out head

[0027] 5: up-down frame

[0028] 7: conveyance mechanism

[0029] 9: servo motor

[0030] 10: encoder

[0031] 11: control device

[0032] 13: servo system control section

[0033] 14: manual command generation section

[0034] 15: teaching data acquisition section

[0035] 17: torque detection section

[0036] 19: collision detection section

[0037] 21: deviation elimination section

[0038] 23: input section

[0039] 24: display section

[0040] 25: alarm DETAILED DESCRIPTION

[0041] Hereinafter, one example of an embodiment of the present application will be described in detail with reference to the accompanying drawings. Figure 1 is a block diagram showing an outline structure of a molded product takeout machine 1 to which one embodiment of the present application is applied. Figure 2 shows a timing chart before and after collision detection in the present embodiment. Figure 3 is a diagram showing one example of display of the input section 23. The molded product takeout machine 1 is a molded product takeout machine in which an upper and lower frame 5 having a takeout head 3 for entering a mold of a molding machine and taking out a molded product from the mold of the molding machine is transported by a three-axis orthogonal type transport mechanism 7. As a drive source of the transport mechanism 7, a plurality of servo motors 9 with encoders 10 are used. In a control device 11 that performs control of the plurality of servo motors 9, a servo system control section 13 for calculating a deviation of a detected value of a position detected by the encoder 10 from a value of a position command and a deviation of a detected value of a speed detected by the encoder 10 from a value of a speed command and performing feedback control of a position and a speed of a drive shaft of the servo motor 9 as a drive section in accordance with these deviations is provided for the plurality of servo motors 9. The servo system control section 13 functions as a so-called servo amplifier.

[0042] In the present embodiment, the control device 11 is provided with a manual command generation section 14 that generates a manual command at the time of manual operation of the servo system control section 13, a teaching data acquisition section 15 that acquires teaching data and performs storage at the time of teaching by performing an operation necessary for performing an appropriate operation, a torque detection section 17, a collision detection section 19, and a deviation elimination section 21. As shown in Figure 2 , the torque detection section 17 detects a torque applied to the upper and lower frame 5 or the takeout head 3 at the time of manual operation of the servo motor 9 by the manual command generation section 14 providing a movement command to the servo system control section 13 from the input section 23 (refer to (A) of Figure 2 Figure 2 ​(B)). In this embodiment, the torque detection unit 17 is configured to detect the torque acting on the extraction head 3 in the lateral direction, the pulling direction, and the vertical direction. Torque detection can be performed by measuring the motor current or by using a torque sensor. Furthermore, in this embodiment, as... Figure 3 As shown, on the display screen of the display unit 24, which includes the input unit 23 for manual operation, three torques proportional to the magnitudes of the torque in the lateral direction, the torque in the pulling direction, and the torque in the vertical direction are displayed (in... Figure 3 The display shows "40%", "150%", and "30%" in the middle. Furthermore, on the display screen of display unit 24, three prompts indicating the retreat direction are shown adjacent to the three torque displays. Figure 3 (The symbols used are "o" and "·"). Additionally, this prompt can be displayed as text, a marker, or an indicator light. With such a display, the operator can accurately determine, based on the data, which direction to retreat in to reduce torque after a collision. Furthermore, even inexperienced operators can easily perform the retreat maneuver after a collision.

[0043] When the detection value from the torque detection unit 17 becomes larger than a predetermined value, the collision detection unit 19 assumes that the extraction head 3 has collided with a surrounding object and outputs a stop command. In this embodiment, as... Figure 2 As shown in (B), the collision detection unit 19 sets a predetermined value lower than the limit value during automatic operation (e.g., 300% of the rated torque) (limit value × α%: for example, α = 50%). By setting the predetermined value in this way, it prevents the application of excessive loads to surrounding objects during collisions or avoidance actions due to manual operation during teaching operations or after a collision. Furthermore, in this embodiment, the collision detection unit 19 sets a predetermined value at a given time T1 (refer to...). Figure 2 When the torque detection unit 17 detects a value that is larger than a predetermined value within (B) "β seconds", it is assumed that the removal head 3 has collided with a surrounding object and an action stop command is output (see reference). Figure 2 (E)). If a collision is immediately determined when the torque exceeds a predetermined value, it may be incorrectly determined to be a collision during operations such as tapping. Therefore, it is set as follows: if the torque continues to exceed the limit value × α% after a period of β seconds (specifically 0.2 to 0.3 seconds), it is determined that a collision has occurred.

[0044] Furthermore, the collision detection unit 19 outputs an alarm signal approximately simultaneously with the output of the action stop command (see reference). Figure 2The error flag (C) is then displayed. Then, in order to perform a retreat operation, a movement command based on manual operation is input again from the manual command generation unit 14 to the servo system control unit 13 by operating the input unit 23 (becoming a manual operation flag). Figure 2 After the timing of "moving in the opposite direction" in (A), after the detection value of the torque detection unit 17 becomes smaller than the aforementioned predetermined value (flag 1 becomes 0), until a given time has elapsed (refer to...). Figure 2 Until (B) γ seconds) (time T2), the alarm signal is continuously output. Figure 2 (C) error flag). Furthermore, even when a "move in the opposite direction" command is input, the torque gradually decreases from the collision state to 0, so the limit value × α% does not immediately become 0. Moreover, during the output alarm signal period, alarm 25 warns the operator through sound, images, etc. Additionally, a waiting time T2 of γ seconds is set to provide the operator with an opportunity to re-perform the retraction operation if an error occurs. That is, when the torque in the pulling direction is high due to a collision, it is necessary to move the upper and lower frames 5 in the direction where the torque in the pulling direction becomes 0. However, if the operator manually moves the upper and lower frames 5 vertically, the extraction head 3 may sometimes move vertically while being pressed against the object being collided with a strong force, damaging the extraction head 3. Therefore, a waiting time T2 of γ seconds is set to provide the operator with the time needed to make a correct judgment.

[0045] When the collision detection unit 19 outputs a stop command, the deviation clearing unit 21, while maintaining the servo system control unit 13 of the servo motor in the on state, performs a deviation clearing operation to make the deviation calculated in the servo system control unit 13 zero. In this embodiment, the deviation clearing unit 21 is as follows: Figure 2 As shown in (D), if a movement command based on manual operation is entered again (see Figure 1), Figure 2 If (A) is cleared, the clearing action will be performed again (see [reference]). Figure 4 (D)).

[0046] According to the control device of the present embodiment, if the operation stop instruction is output from the collision detection section 19, the deviation elimination section 21 performs the elimination operation of making the deviation in the servo system control section 0 while maintaining the on state of the servo system control section, so that the positioning is determined to be completed by the deviation becoming 0, and the operation corresponding to the manual instruction can be performed again. If the deviation is not 0, the operation of the deviation amount is performed before the manual instruction for the retreat operation. This operation has a concern of damaging the take-out head 3, but in the present embodiment, such a problem does not occur. In the present embodiment, when the disengagement operation is performed after the operation is stopped, the servo motor 9 can be operated as instructed by the input section 23 to move the up-and-down frame 5 (take-out head 3), and the retreat from the collision state can be performed smoothly.

[0047] Figure 5 is the actual operation flow at the time of collision detection. In step ST1, it is determined whether the torque value is larger than a given value (limit value x α%). In the case of "No", the manual operation is performed in step ST2, and the servo motor 9 is driven to move the shaft in step ST3. Then, in step ST4, it is determined again whether the torque value is larger than the given value (limit value x α%), and in the case of "Yes", step ST5 is entered, and it is determined whether the timer time Tl is 0. If it is "Yes", the counting of the timer is started in step ST6, and step ST7 is entered. Further, in the case of "No" in step ST5, step ST7 is also entered, and the counting of the timer is continued. Next, in step ST8, it is determined whether the timer time Tl is β, and if it is β, step ST9 is entered, and if it is "No", the process returns to step ST1. If it is "No" in step ST4, step ST41 is entered. It is determined whether the timer time Tl is 0, and if it is "No", the timer is turned off in step ST42, and the timer time Tl is set to 0 in step ST43, and the process returns to step ST2. In the case of "Yes" in step ST41, the process also returns to step ST2. If it is determined in step ST8 that the timer time Tl has become β, the error flag becomes active in step ST9, and the stop processing is performed in step ST10. Then, the deviation is eliminated in step ST11, the error pop-up (error display) is issued as an alarm in step ST12, and the buzzer issues an alarm as an alarm in step ST13. Then, the turning-off operation of the timer is performed in step ST14, and the timer time Tl becomes 0 in step ST15. By the above operation, after the collision is detected, the deviation is reset while the on state of the servo system control section is maintained.

[0048] ​is the flow of actions at the time of collision avoidance. In this example, collision avoidance is performed when the torque value is greater than the limit value x α % at the start. In step ST21, a determination is made as to whether the torque value is less than the limit value x α %. In the case where it is not less (in the case where it is greater), step ST22 is entered, manual operation is performed, the deviation is cleared in step ST23, the action stop command is set to off, and the servo motor is driven in step ST24 to move the shaft. Then, in step ST25, a determination is made as to whether the torque value is less than the limit value x α %. In the case where the torque value is less than the limit value x α %, step ST26 is entered, a determination is made as to whether the timer time T2 is 0. In the case where the timer time T2 is 0, the counting of the timer is started in step ST27. In the case where the timer time T2 is not 0, the counting of the timer is continued in step ST28. In the case where the torque value is not less than the limit value x α % in step ST25, step ST251 is entered, a determination is made as to whether the timer time T2 is 0. If it is 0, step ST21 is returned to, and if it is not 0, step ST252 is entered, the timer is set to off, and the timer time T2 is set to 0 (initialized) in step ST253, and step ST21 is returned to. Through the counting of the timer time in step ST28, a determination is made as to whether the timer time has become γ in step ST29. If it is "No", step 21 is returned to, and if it is "Yes", an error flag is set to off in step ST30 for the collision avoidance action, the buzzer is set to off in step ST31, the counting of the timer time T2 is set to off in step ST32, and the timer time T2 is set to 0 (initialized) in step ST33. Thus, avoidance from the collision state is performed.

[0049] [Modified example]

[0050] The torque detection section is preferably configured to be able to detect the direction of action of the torque acting on the pickup head from various directions. For example, in the case where the number of shafts driven by the servo motor is 5 shafts, 6 shafts, or the like, the torque detection section can be configured to be able to detect the torque of all of the multi-shaft. Further, in the case where the pickup head is equipped in the posture control device, the torque detection section can be configured to be able to detect the torque applied to the pickup head from the posture control device. Furthermore, the display section of the input section for performing manual operation preferably displays torque displays that are proportional to the magnitudes of all of the torques detected by the torque detection section. These torque displays can be any of numerical value displays, bar graph displays, and meter displays. Further, prompt displays that prompt the avoidance direction are preferably displayed adjacent to the torque displays of the display section of the input section. The prompts can be any of character displays, mark displays, and light displays.

[0051] Industrial applicability

[0052] According to the present application, if the output operation stop instruction is output, the deviation elimination section performs an elimination operation that makes the deviation of the servo system control section zero while maintaining the open state of the servo system control section, so that positioning is completed by the deviation becoming zero, and operation can be performed again. As a result, when the retreat operation is performed after operation is stopped, the servo motor can be operated in accordance with the operation instruction to move the upper and lower frames and the take-out head, so that retreat can be performed smoothly from the collision state.

Claims

1. A control device of a molded article take-out machine, comprising: a servo system control section that detects a position and a speed of a driving section of a servo motor that drives a frame having a take-out head in the molded article take-out machine with an encoder, calculates a deviation of a detected value of the position from a value of a position command and a deviation of a detected value of the speed from a value of a speed command, and controls the servo motor by feedback control of the position and the speed of the driving section in accordance with these deviations; and a manual command generation section that generates a manual command when a manual operation is performed on the servo system control section, characterized by further comprising: a torque detection section that detects a torque applied to the frame when a manual operation is performed on the servo motor by providing an operation command from the manual command generation section to the servo system control section in accordance with the manual command; a collision detection section that outputs an operation stop command when it is determined that the take-out head has collided with a surrounding object when a detected value of the torque detection section becomes larger than a predetermined value; and a deviation cancel section that, if the operation stop command is output, performs a cancel operation that makes the deviations of the detected values of the position and the speed in the servo system control section from the values of the position command and the speed command zero in a state in which the servo system control section is maintained in an on state and the torque is maintained.

2. The control device of a molded article take-out machine according to claim 1, characterized in that the collision detection section sets the predetermined value to a value lower than a limit value at the time of automatic operation.

3. The control device of a molded article take-out machine according to claim 1 or 2, characterized in that the collision detection section outputs the operation stop command when the detected value of the torque detection section is continuously detected to become larger than the predetermined value for a given time, and determines that the take-out head has collided with a surrounding object.

4. The control device of a molded article take-out machine according to claim 3, characterized in that the collision detection section outputs an alarm signal at substantially the same time as the operation stop command is output, and continuously outputs the alarm signal until a given time elapses after the detected value of the torque detection section becomes smaller than the predetermined value again when a movement command is input from the manual command generation section to the servo system control section again after retreat from the collision detection.

5. The control device of a molded article take-out machine according to claim 4, characterized in that the deviation cancel section performs the cancel operation again when the movement command is input from the manual command generation section again.

6. The control device of a molded article take-out machine according to claim 1 or 2, characterized in that the torque detection section is configured to be able to detect a direction of action of the torque acting on the take-out head, and a display section of an input section for performing the manual operation displays the direction of action of the torque and a torque display that is proportional to the magnitude of the torque.

7. The control device of a molded article take-out machine according to claim 6, characterized in that ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ In the display section, a display for prompting a retreat direction is shown adjacent to the torque display.

8. The control device of the shaped article take-out machine according to claim 6, wherein The torque detection section is configured to be able to detect a torque in the cross direction, a torque in the pulling direction, and a torque in the up-down direction acting on the take-out head, In a display section of the input section for performing the manual operation, three torque displays proportional to the magnitude of the torque in the cross direction, the torque in the pulling direction, and the torque in the up-down direction are shown.

9. The control device of the shaped article take-out machine according to claim 8, wherein In the display section, three displays for prompting a retreat direction are shown adjacent to the three torque displays, respectively.

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