JP2004025191A - Punch press driven with servomotor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a punch press driven with a servomotor with which the overheat of a motor is prevented without using a large-output motor. <P>SOLUTION: A temperature detecting means 36 for detecting the temperature of the servomotor 19 which is used as a driving source for punching work is provided. A servomotor temperature lowering means 37 for lowering the temperature of the servomotor 19 and a control means 38 corresponding to temperature by which a servomotor temperature lowering means 37 is driven when the motor temperature detected by the temperature detecting means 36 is not lower than a setting value are provided. The servomotor temperature lowering means 37 is taken as a hit rate limiting means 39 for making the hit rate which shows the number of punching per unit time lower than a predetermined hit rate. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a servomotor driven punch press using a servomotor as a driving source for punching.
[0002]
[Prior Art and Problems to be Solved by the Invention]
The servo motor-driven punch press can perform processing with a higher degree of freedom, such as a change in the speed pattern during a ram stroke, as compared to a mechanical punch press using a conventional flywheel. However, since punching is performed directly with the torque of the motor without using the inertia of the flywheel, the load on the motor is increased. For this reason, the motor may be overheated by the continuous processing. If a motor with sufficient output power is used, the problem of overheating does not occur, but the use of a high-power motor increases costs and also requires measures such as hardening the press frame. Increases costs.
[0003]
An object of the present invention is to provide a servo motor driven punch press that can prevent overheating of a motor without using a motor having a large output.
Another object of the present invention is to prevent overheating of a motor without lowering the efficiency of punching as much as possible.
Still another object of the present invention is to be able to maintain punching efficiency while preventing motor overheating.
[0004]
[Means for Solving the Problems]
The configuration of the present invention will be described with reference to FIG. 1 corresponding to the embodiment. This servo motor driven punch press is a punch press using a servo motor (19) as a driving source for punching, and includes a temperature detecting means (36) for detecting a temperature of the servo motor (19), and a temperature of the servo motor (19). And a temperature for driving the servo motor temperature lowering means (37) when the temperature of the servo motor (19) detected by the temperature detecting means (36) becomes equal to or higher than a set temperature. And a corresponding control means (38).
According to this configuration, if the temperature of the servomotor (19) becomes higher than the set temperature during operation, the temperature corresponding control means (38) for lowering the temperature of the servomotor (19) reduces the temperature of the servomotor (37). Is driven. Therefore, overheating of the motor (19) can be prevented without using a high-output motor.
[0005]
The servo motor temperature lowering means (37) may include hit rate limiting means (39) for lowering a hit rate indicating the number of punches per unit time from a predetermined hit rate. The servo motor temperature lowering means (37) may be the hit rate limiting means (39) alone or may be used in combination with other means. Here, the “predetermined hit rate” does not necessarily have to be a value indicated by a numerical value or the like as a ratio, for example, in a predetermined basic relationship defined as an operation relationship between the plate material movement and the punching operation. There may be.
The reduction in the hit rate is to increase the interval between each punch operation. In the punching operation, the lowering of the ram (8) at the rising standby position is normally started immediately after the positioning of the plate (W) by the movement of the plate. Also, in anticipation of the completion of positioning, synchronous control of the movement of the plate material and the punching operation is performed so as to start slightly earlier than the completion of positioning. In such control, the hit rate is limited, for example, by slowing down the speed of the movement of the plate, or by starting the descent of the ram after waiting for a predetermined time after the movement of the plate is completed. The limitation by the hit rate limiting means (39) is performed when the servo motor temperature becomes equal to or higher than the set temperature, and is not limited until then, so that overheating can be prevented without lowering the punching efficiency as much as possible. it can.
[0006]
The hit rate limiting means (39) can perform, for example, a plurality of levels of limitation different in degree of limitation, and the temperature correspondence control means (38) sets a plurality of set temperatures and sets the temperature detection means. When the detected servo motor temperature exceeds each set temperature, the hit rate limiting means (39) may perform the hit rate limitation at the stage corresponding to the set temperature that has been exceeded. For example, the hit rate may be limited to two or three steps, and the hit rate at the final step may be stopped by stopping the servo motor (19).
When the temperature detected by the temperature detecting means (36) falls below the set temperature for release, the temperature corresponding control means (38) drives the servo motor temperature decreasing means (37), for example, hit rate limiting. The restriction by means (39) may be released.
[0007]
The servo motor temperature lowering means (37) may include a fan (40) for applying an air flow to the servo motor (19). The fan (40) may flow air inside the servo motor (19) to the outside of the motor, or may flow air around the motor to a position away from the motor (19). In this case, the servo motor temperature lowering means (37) may be only the fan (40) or may be used in combination with another means, for example, the hit rate limiting means (39).
In this configuration, since the servo motor (19) is cooled by the fan (40), the efficiency of punching can be maintained while preventing the servo motor (19) from overheating.
When the hit rate limiting means (39) and the fan (40) are used in combination as the servo motor temperature lowering means (37), the restriction on the hit rate can be canceled earlier.
[0008]
BEST MODE FOR CARRYING OUT THE INVENTION
One embodiment of the present invention will be described with reference to FIGS. As shown in FIG. 1, this servo motor driven punch press is composed of a punch press main body 1 which is a mechanical portion, and a control device 2 for controlling the punch press main body 1.
As shown in FIGS. 2 and 3, the punch press body 1 has a plate material moving unit 3 for moving a plate material W and a processing unit 4 for performing punching, which are installed on a frame 5. The processing means 4 includes a punch driving means 9 for driving the ram 8 for raising and lowering the punch tool 6 by a driving force of a servo motor 19, a tool holding means 10 for holding the punch tool 6 and a die tool (not shown), 11 is comprised. The tool holding means 10 and 11 consist of turrets installed coaxially with each other. The punch tool 6 may be for drilling or for forming.
[0009]
The plate material moving means 3 is a table device for holding the plate material W with the work holder 12 and moving the plate material W on the table 13 in the front-back direction (Y-axis direction) and the left-right direction (X-axis direction). The table 13 includes a fixed table 13a and a movable table 13b. The movable table 13b moves back and forth on the rail 15 of the frame 5 together with the carriage 14. A cross slide 16 is mounted on the carriage 14 so as to be movable left and right, and a plurality of work holders 12 are mounted on the cross slide 16. The carriage 14 and the cross slide 16 are driven by servomotors 17 and 18 of each axis via a motion conversion mechanism such as a ball screw.
[0010]
The punch driving means 9 uses a servo motor 19 as a drive source, has a rotation / linear motion conversion mechanism 20 for converting the rotation of the servo motor 19 into the elevation of the ram 8, and moves the punch tool 6 up and down by the ram 8. is there. The ram 8 is set up and down on the frame 5 at a predetermined ram position P (FIG. 3), and raises and lowers the punch tool 6 of the tool holding means 10 indexed to the ram position P. The servo motor 19 is provided with a cooling fan 40 (FIG. 1) in the vicinity thereof. The fan 40 may flow air inside the servomotor 19 to the outside of the motor, or may flow air around the motor to a position away from the motor 19.
[0011]
In FIG. 1, a control device 2 includes a numerical control device (NC device) using a computer and a programmable controller, and is a program control type that decodes and executes a machining program 31.
The control device 2 includes a sheet material movement control means 32 for controlling the sheet material movement means 3, a ram axis control means 33 for controlling the punch driving means 9, and a sequence control means for performing various sequence controls of the punch press body 1 (not shown). And decoding execution means 35 for decoding the machining program 31 and giving commands of the machining program 31 to the control means 32, 33,...
[0012]
The machining program 31 is stored in a program memory or externally read into the decryption execution means 35. The machining program 31 is described in NC code or the like, and is an X-axis movement command and a Y-axis movement command, which are plate material movement commands for causing the plate material moving means 3 to move in the X-axis direction and the Y-axis direction, respectively, A punch command for giving a command for a lifting operation to the means 9 and a sequence command (not shown) for controlling a sequence operation of each part of the punch press body 1 are described.
[0013]
The board movement control means 32 is means for controlling the X-axis and Y-axis servomotors 17 and 18 of the board movement means 3 and has a servo controller (not shown). The plate material movement control means 32 is provided for each of the servomotors 17 and 18 for each axis. In FIG. 1, the means for both axes is shown as a single block. The sheet material movement control means 32 has a synchronization control unit (not shown), and starts moving the sheet material W when the punch tool 6 has punched the sheet material W and has risen to an exit height at which the sheet material W does not contact. The plate material moving means 3 is controlled so that Further, as shown in FIG. 4 (A), the plate material movement control means 32 changes the plate material movement speed into a trapezoidal speed curve in which a constant acceleration section, a constant speed section, and a constant acceleration deceleration section occur. I do.
[0014]
In FIG. 1, the ram axis control means 33 is means for controlling the servo motor 19 of the punch driving means 9 and has a servo controller (not shown). As a basic control, the ram axis control unit 33 rotates the rotation / linear motion conversion mechanism 20 in one direction, and when the plate material movement by the plate material movement unit 3 is completed, the punch tool 6 starts lowering from the rising standby position. To control. In addition to the above, the basic control by the ram axis control means 33 may be such that the punch tool 6 is controlled to reach the height just before the contact of the sheet when the sheet movement by the sheet moving means 3 is completed.
[0015]
In this embodiment, in the servo-motor-driven punch press having the above configuration, a temperature detecting unit 40 for detecting the temperature of the servo motor 19 of the punch driving unit 9, a servo motor temperature lowering unit 37 for lowering the temperature of the servo motor 19, When the temperature of the servo motor 19 detected by the temperature detecting means 36 becomes equal to or higher than a set value, a temperature corresponding control means 38 for driving the servo motor temperature decreasing means 37 is provided. The servo motor temperature lowering means 37 includes a hit rate limiting means 39 and the fan 40 provided for the servo motor 19. When the temperature detected by the temperature detecting means falls below the set temperature for release, the temperature corresponding control means stops the driving by the servo motor temperature decreasing means 37. The stop of the driving is a limitation by the hit rate limiting unit 39 and a stop of the driving of the fan 40.
[0016]
The hit rate limiting means 39 is means for making a hit rate indicating the number of punches per unit time lower than a predetermined hit rate. The predetermined hit rate is not a value shown as a numerical value, but is a value between the sheet movement and the punch operation in which the descending operation by the punch driving means 9 is started when the sheet movement by the sheet movement means 3 is completed as described above. It is a basic operation relationship. In this basic operation relationship, the operation of starting the lowering operation by the punch driving means 9 upon completion of the movement of the plate includes the case of starting the lowering operation earlier than the completion in anticipation of the completion of the movement of the plate. Shall be considered.
[0017]
The reduction of the hit rate by the hit rate limiting means 39 may be a method of reducing the plate material moving speed or a method of delaying the start of the punch operation. In FIG. 1, the hit rate limiting means 39 is shown to have both the sheet material moving speed lowering means 41 and the punch start delaying means 42, but may have only one of them. The plate material moving speed reducing unit 41 is a unit that reduces the maximum speed of the plate material moving by the plate material moving unit 3. Instead of lowering the maximum speed or in combination with the reduction of the maximum speed, the plate material moving speed reducing means 41 sets the acceleration / deceleration time constant so that the plate material moving means 3 accelerates and decelerates the plate material movement slowly. It may be changed. The punch start delay unit 42 is a unit that causes the punch driving unit 9 to start lowering the punch operation after waiting for a set delay time after the plate material movement by the plate material moving unit 3 is completed.
[0018]
The operation of the above configuration will be described. In FIG. 4, a curve a indicates a change in the plate moving speed by the plate moving means 3, and a curve b indicates a change in the ram position by the driving of the punch driving means 9.
Normally, as shown in FIG. 3A, when the plate material movement by the plate material moving means 3 is completed, the punch driving means 9 starts lowering from a predetermined rising standby position, and the ram position returns to the rising standby position. At this point, the next plate movement by the plate movement means 3 is started. Therefore, when the plate material moving distance is constant, punching cycle time becomes T _0. Such a basic operation relationship between the plate material movement and the punch operation is provided. The number of punches per unit time (1 / T ₀ ) determined by this operation relationship is the basic hit rate. Incidentally, the cycle time T _0, when the spacing between holes punching are different, various changes according to the distance.
[0019]
It is assumed that the temperature detected by the temperature detecting means 36 of the servo motor 19 of the punch driving means 9 has risen to a temperature equal to or higher than the temperature set by the temperature corresponding control means 38 during the operation. When the temperature rises in this way, the temperature correspondence control means 38 drives the servo motor temperature decrease means 37. As this driving, the hit rate is limited by the hit rate limiting means 39 and the fan 40 is activated.
The hit rate limiting means 39 reduces, for example, as shown in FIG. 4B, the maximum speed of the plate material moving speed by the plate material moving means 3. Therefore, a longer sheet travel time, lowering the start of the next punch operation by the punch drive means 9 so that the delay, punching cycle time is delayed and T _1. Thus, the hit rate is decreased to 1 / _{T 1.}
Hit rate limiting means 39, instead of lowering the maximum speed, as shown in FIG. (C), after completion of plate movement by sheet moving means 3, waits a predetermined delay time T _2, the punch drive means 9 Of the next punching operation may be started. Even such a case, punching cycle time is slowed and T _1, the hit rate is decreased to 1 / T _1.
[0020]
By limiting the hit rate in this manner, the frequency of use of the servo motor 19 is reduced, and the overheating of the servo motor 19 is prevented. Due to the hit rate limitation, the servo motor temperature gradually decreases. When the servo motor temperature falls below the set temperature for judging decrease, the temperature correspondence control means 38 releases the restriction by the hit rate restriction means 39 and stops driving the fan 40. Therefore, it is possible to prevent the servo motor 19 from overheating without lowering the punching efficiency while maintaining the normal hit rate as much as possible. In this embodiment, since the servo motor 19 is cooled by the fan 40 in addition to the restriction by the hit rate restriction means 39, the restriction on the hit rate is quickly released.
It is preferable that the set temperature of the servo motor temperature drop determination is lower than the set temperature of the rise determination, thereby avoiding frequent repetition of start and release of hit rate limitation.
[0021]
In the above embodiment, the hit rate is limited to one step, but may be limited to a plurality of steps. That is, the hit rate limiting means 39 can perform, for example, a plurality of levels of limitation different in degree of limitation, and the temperature correspondence control means 38 sets a plurality of set temperatures and detects the temperature by the temperature detecting means 36. When the servo motor temperature exceeds each set temperature, the hit rate limiting means 38 may perform a hit rate limit at a stage corresponding to the set temperature. In this case, the hit rate is limited to two or three levels, and the hit rate at the final level may be the stop of the servomotor 19.
By limiting the hit rate in a plurality of stages in this way, overheating can be prevented while maintaining the punching efficiency as high as possible.
[0022]
【The invention's effect】
The servo motor driven punch press according to the present invention includes a temperature detecting unit for detecting a temperature of the punch press, a servo motor temperature lowering unit for lowering the temperature of the servo motor, and a temperature of the servo motor detected by the temperature detecting unit. As described above, since the temperature corresponding control means for driving the servo motor temperature lowering means is provided, overheating of the motor can be prevented without using a high output motor.
When the servo motor temperature lowering means includes a hit rate indicating the number of punches per unit time, a hit rate limiting means for lowering the hit rate than a predetermined hit rate, without lowering the efficiency of punching as much as possible, It is possible to prevent overheating of the motor.
When the servomotor temperature lowering means includes a fan for applying an airflow to the servomotor, it is possible to maintain punching efficiency while preventing overheating of the motor.
[Brief description of the drawings]
FIG. 1 is a block diagram showing a conceptual configuration of a servo motor driven punch press according to an embodiment of the present invention.
FIG. 2 is a front view showing a punch press body of the servo motor-driven punch press.
FIG. 3 is a plan view of the punch press body.
FIG. 4 is a graph showing a relationship between a state before hit rate limitation and each example of hit rate limitation.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Punch press main body 2 ... Control device 3 ... Plate material moving means 4 ... Processing means 8 ... Ram 17, 18 ... Servo motor 19 of each axis ... Servo motor 20 of a punch drive source ... Rotation / linear motion conversion mechanism 32 ... Plate material movement Control means 33 ram axis control means 35 decoding execution means 36 temperature detecting means 37 servo motor temperature lowering means 38 temperature control means 39 hit rate limiting means 40 fan W plate material

Claims (3)

In a punch press using a servo motor as a driving source for punching, a temperature detecting means for detecting the temperature of the servo motor, a servo motor temperature lowering means for lowering the temperature of the servo motor, and a servo motor detected by the temperature detecting means. A servo motor-driven punch press provided with temperature-dependent control means for driving the servo motor temperature lowering means when the temperature exceeds a set temperature. 2. The servo motor driven punch press according to claim 1, wherein said servo motor temperature lowering means includes a hit rate limiting means for lowering a hit rate indicating the number of punches per unit time than a predetermined hit rate. 3. The punch press according to claim 1, wherein said servo motor temperature lowering means includes a fan for applying an air flow to the servo motor.

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