JP3083101B2 - Press equipment - Google Patents

Description

The present invention relates to a press device such as a semiconductor lead forming device.

[Conventional technology]

Conventionally, as a press device for a semiconductor lead forming device, there are a hydraulic press type and a crank press type.

As the hydraulic press type, there is one described in Japanese Patent Publication No. 61-57707. As the crank press type, there is one described in Japanese Patent Application Laid-Open No. 1-161739.

The problems with the hydraulic press type are that the switching of the hydraulic pressure becomes large-scale, the generated vibration and noise are large, the controllability such as ram speed, pressing force, bottom dead center accuracy is poor, the shape is large, and the efficiency is poor. No.

Another problem with the crank press type is that the pressing force occurs only at a few mm near the bottom dead center, and the working range is narrow.

[Problems to be solved by the invention]

The present invention has improved controllability, reduced noise, downsized shape,
Improving efficiency and expanding the range of use are to be solved.

[Means for solving the problem]

The present invention provides a ball screw shaft which is rotationally driven by a servomotor and forms a right-hand screw and a left-hand screw from a central portion in a longitudinal direction, and a right nut and a left nut screwed to the right-hand screw and the left-hand screw of the ball screw shaft, respectively. The tip is rotatably fixed to these right nut and left nut,
It consists of a pair of links whose base ends are rotatably fixed to the upper end of the ram, and a ram supported so that it can move up and down in the vertical direction.
Further, in a press apparatus using a positioning servo using an incremental encoder for detecting the rotational position of the servomotor, the incremental machine is used to set a stroke exceeding the bottom dead center of the mold and to lower the mold in order to generate a pressing force. A circuit for maintaining the current position by separately counting two rectangular pulses A and B output with a phase difference of 90 degrees from the encoder is added, and the count data is taken into the control unit, and the return amount is calculated. Press apparatus, comprising: a control unit for performing high-speed positioning with an offset amount smaller by a predetermined pulse amount from the return amount, and performing an origin return operation corresponding to the offset amount by an origin adjusting operation therefrom. Solved the above problem.

[Action]

In the present invention, when the servomotor is driven, the ball screw rod rotates in a certain direction. A right-handed screw and a left-handed screw are formed on the ball screw shaft, and the right nut and the left nut are screwed together, so that the two nuts approach or separate from each other. A pair of links are rotatably fixed to both nuts, and the base end of the link is rotatably fixed to the upper end of the ram, so that the ram moves up and down.

〔Example〕

Hereinafter, the present invention will be specifically described with reference to examples.

FIG. 1 is a front view showing an embodiment of the present invention, FIG. 2 is a side view thereof, and FIG. 3 is a side view of a link portion.

In these figures, 1 is a case, 2 is a servomotor, and 4 is an operation panel.

A ball screw shaft 5 is rotatably supported in the case 1 by bearings 6 and 7. The ball screw shaft 5 has a right screw 5a from the center to the right and a left screw 5b from the center as shown in FIG. Are formed. The right nut 8 and the left nut 9 screwed to the right screw 5a and the left screw 5b do not rotate with the rotation of the ball screw shaft 5 and can move along the longitudinal direction king of the ball screw shaft 5. It is attached to a linear bearing 10 provided on the case 1 so as to be movable left and right.

The right nut 8 and the left nut 9 have left and right shafts 11 projecting therefrom. The upper ends of the right link 12 and the left link 13 are rotatably mounted on the shaft 11. The lower ends of the right link 12 and the left link 13 are connected to a common pivot 15
Attached to.

Pulleys 16 and 17 are attached to the output shaft of the servomotor 2 and the ball screw shaft 5, respectively. A timing belt 18 is suspended between the pulleys 16 and 17 to transmit rotation. The rotational position of the servo motor 2 is detected by a rotary encoder 19.

The interior of the case 1 is filled with lubricating oil up to the position of the ball screw shaft 5, and the ball screw shaft 5 and the ram 14 are sealed to the case 1 by an oil seal 20.

A detection arm for detecting the position of the ram 14 is provided below the ram 14.
The detection arm 21 is fixed, and a detection rod 22 is connected to the tip of the detection arm 21. Then, the tip position of the detection rod 22 is detected by the photosensors 23 arranged at different heights.

 24 is an electromagnetic brake.

A control method of the press device configured as described above will be described.

FIG. 4 is a block diagram showing the configuration of the control system. Reference numeral 31 denotes a setting section for setting the lower position and the upper position of the ram 14, and 32A and 32B are output from the rotary encoder 24 with a phase difference of 90 degrees.
An addition counter and a subtraction counter for counting pulse data of two rectangular pulses A phase and B phase; a calculation control unit 33 for calculating a command value from the setting unit 31 and a count pulse from the addition counter 32A and the subtraction counter 32B; Reference numeral 34 denotes a servo motor driver that drives the servo motor 2 based on the command signal calculated by the calculation control unit 33 and the position feedback pulse from the rotary encoder 19.

In this embodiment, as the rotary encoder 19,
The A phase and the B phase are separately counted using an incremental encoder.

Incidentally, in order to generate a pressing force using the positioning servo, a stroke exceeding the bottom dead center of the mold is set and lowered. However, at this time, since the amount of return rise becomes unknown, as a countermeasure, a deceleration point sensor is provided near the top dead center, and high-speed return to origin is performed up to that point, and low-speed operation is performed from the deceleration point to the origin.

Stop the incremental encoder and install an absolute encoder.

And so on.

In the method of (1), it takes time to return, and the index time of the device becomes longer. In the method (1), the index time can be improved, but the cost increases.

Therefore, in this embodiment, by separately counting the A-phase and the B-phase of the incremental encoder, it is possible to reciprocate the encoder slit at the bottom dead center due to the reaction force of the mold when pressurizing, particularly at the bottom dead center. A circuit has been added that can maintain the current position with considerable accuracy even when vibration occurs. This counter data is fetched by the control unit, and after the calculation, the return amount is determined. However, even if the above +/- counting is performed, an error of ± 1 pulse is generated. The rest is the origin adjustment operation. By doing so, accurate operation can be performed each time at a low cost without significantly affecting the index time.

FIG. 5 is a flowchart showing a specific control example.

 The processing of each step in FIG. 5 is as follows.

Step 100: Clear the servo count. Specifically, the addition counter 32A, the subtraction counter 32B, the operation control unit 33,
The respective count values of the servo motor driver 34 are cleared to zero.

Step 110: Start reading the motor feedback pulse count.

Step 120: The servo motor 2 is driven by the data set in advance on the operation pulse to start the lowering of the ram 14 to perform the pressing operation. The setting contents include moving distance + offset, acceleration / deceleration point, and each speed setting accordingly.

Step 130: A pulse corresponding to the descending command movement amount given to the servo driver is sampled.

Step 140: The target deceleration point set on the operation panel is compared with the commanded moving amount to make a judgment. That is, it is determined how much the command movement amount has now issued and has reached the target deceleration point.

Step 150: After confirming the deceleration point in step 140, the motor changes the speed at the set deceleration speed.

Step 160: The servo driver waits for a positioning completion signal of the moving distance−offset = moving distance for the moving distance set on the operation panel.

Step 170: After the positioning is completed, the stroke ends physically (by a mold stopper or the like), but the motor tries to rotate by the offset amount, and the motor generates the maximum torque. In this step, the motor torque is limited.

Step 180: Hold the state of step 170 for the time set on the operation panel.

Step 190: The offset amount in step 170 is cleared to zero. (End of pressurization) Step 200: Read the position of the motor with the acceleration / deceleration counter.

Step 210: In order to surely operate the motor, a negative offset of about -10 pulses (about 0.01 mm) is issued, and a rising movement command is issued.

Step 220: The motor rises.

Step 230: The same operation as step 130 is performed.

Step 240: Compare and determine the target acceleration (point and sampling data) set by the operation panel. Step 250: Change to the acceleration speed set by the operation panel.

Step 260: It is determined by the positioning completion signal that the movement amount specified in step 210 is reached.

Step 270: The motor returns to the origin at the origin speed by a negative offset distance.

Step 280: After detecting the Z phase of the motor, the motor stops.

〔The invention's effect〕

As described above, the present invention has the following effects.

The shape of the press device can be reduced.

Noise generated by the press device can be suppressed.

The impact force and impact sound at the time of the mold stopper collision can be suppressed.

With a simple setting, the optimum pressing state can be set for the workpiece.

[Brief description of the drawings]

1 is a front view showing an embodiment of the present invention, FIG. 2 is a side view thereof, FIG. 3 is a side view of a link portion, FIG. 4 is a block diagram showing a configuration of a control system, and FIG. 6 is a flowchart showing a typical control example. 1: Case, 2: Servo motor 4: Operation panel, 5: Ball screw shaft 5a: Right screw, 5b: Left screw 6,7: Bearing, 8: Right nut 9: Left nut, 10: Linear bearing 11: Shaft, 12 : Right link 13: Left link, 14: Ram 15: Axis, 16, 17: Pulley 18: Timing belt 19: Rotary encoder 20: Oil seal, 21: Detection arm 22: Detection rod, 23: Photo sensor 24: Electromagnetic brake 31: Setting unit, 32A: Addition counter 32B: Subtraction counter, 33: Operation control unit 34: Servo motor driver

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁷ , DB name) B30B 1/10 B30B 1/18 B30B 15/14

Claims (1)

(57) [Claims] 1. A ball screw shaft which is rotationally driven by a servomotor and has a right-hand screw and a left-hand screw formed from a central portion in a longitudinal direction, a right nut and a left nut screwed to the right-hand screw and the left-hand screw of the ball screw shaft, respectively. Nut, the tip is rotatably fixed to these right nut and left nut,
It consists of a pair of links whose base ends are rotatably fixed to the upper end of the ram, and a ram supported so that it can move up and down in the vertical direction.
Further, in a press apparatus using a positioning servo using an incremental encoder for detecting the rotational position of the servomotor, the incremental machine is used to set a stroke exceeding the bottom dead center of the mold and to lower the mold in order to generate a pressing force. A circuit for maintaining the current position by separately counting two rectangular pulses A and B output with a phase difference of 90 degrees from the encoder is added, and the count data is taken into the control unit, and the return amount is calculated. Press apparatus, comprising: a control unit for performing high-speed positioning with an offset amount smaller by a predetermined pulse amount from the return amount, and performing an origin return operation corresponding to the offset amount by an origin adjusting operation therefrom. .