JPH04100697A - Pressing apparatus - Google Patents

Abstract

PURPOSE:To improve the characteristics of a pressing apparatus by composing of right and left links fixing the tip parts freely rotatively to a right nut and a left nut fastened on right screw and left screw in a ball screw shaft and fixing the basis end to upper end of a ram and the ram supported so as to be ascendable/descendable. CONSTITUTION:By driving a servo motor 2, the ball screw shaft 5 is turned to the fixed direction. In this ball screw shaft, the right screw 5a and the left screw 5b are formed, and since the right nut 8 and the left nut 9 are screwed, respectively, both nuts are mutually approached or left. In both nuts, as one pair of the links 12, 13 are fixed as swingable, the ram is made to ascend/ descend. By this method, the pressing apparatus is miniaturized and the generation of noise is suppressed and impact force and impact noise at the time of colliding a stopper in a die, are suppressed, and the optimum pressing condition to a material to be worked can be set.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a press device such as a semiconductor lead forming device.

[Conventional technology]

Conventionally, there are two types of press equipment for semiconductor lead forming equipment: a hydraulic press type and a crank press type.

As a hydraulic press type, there is one published in Japanese Patent Publication No. 57707/1988. Further, as a 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 hydraulic pressure is changed on a large scale, the generated vibration and noise are large, the controllability of ram speed, pressurizing force, bottom dead center accuracy, etc. is poor, the shape is large, and the efficiency is poor. Can be mentioned.

Further, a problem with the crank press type is that the pressurizing force is only generated a few mm near the bottom dead center, which limits the range of use.

[Problem to be solved by the invention]

This development aims to improve controllability, reduce noise, reduce size, improve effectiveness, and expand the range of use.

[Means to solve the problem]

The present invention provides a ball screw shaft that is rotationally driven by a servo motor and has a right-hand thread and a left-hand thread formed from a longitudinal center portion thereof, and a right-hand nut and a left-hand nut that are screwed into the right-hand thread and left-hand thread of the ball screw shaft, respectively. , a pair of links whose tips are rotatably fixed to these right and left nuts, and whose base ends are rotatably fixed to the upper end of the ram, and a ram supported vertically so as to be movable up and down. The above problem was solved by the constructed press device.

[Effect]

In the present invention, when the servo motor is driven, the ball screw rod rotates in a fixed direction. This ball screw shaft is formed with a right-hand thread and a left-hand thread, and a right-hand nut and a left-hand nut are screwed together, respectively, so that both nuts approach or separate from each other. A pair of links are rotatably fixed to both nuts, and the base ends of the links are 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 the case, 2 is the servo motor,
4 is an operation panel.

Inside the case 1, a ball screw shaft 5 is rotatably supported by bearings 6 and 7, and as shown in FIG. 5b is formed. The case is designed so that the right nut 8 and the left nut 9, which are screwed into the right-hand screw 5a and the left-hand screw 5b, do not rotate with the rotation of the ball screw shaft 5 and can move along the longitudinal direction of the ball screw shaft 5. It is attached to a linear bearing 10 provided at 1 so as to be able to move left and right.

The right nut 8 and the left nut 9 have shafts 11 projecting from the left and right, and the upper ends of the right link 12 and the left link 13 are rotatably attached to the shaft 11.

The lower ends of the right link 12 and the left link 13 are attached to a common pivot 15 provided on the top of the ram 14.

Boots J16 17 are attached to the output shaft of the servo motor 2 and the ball screw shaft 5, respectively, and a timing belt 18 is connected to both boots IJ16 17 to transmit rotation. The rotational position of the servo motor 2 is detected by a row encoder 19.

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

A detection arm 21 for detecting the position of the ram 14 is fixed to the lower part of the ram 14, and a detection rod 22 is connected to the tip of the detection arm 21. and detection rod 22
Photosensors 23 whose tip positions are arranged at different heights
I am trying to detect it with .

Note that 24 is an electromagnetic brake.

A method of controlling the press apparatus configured as described above will be explained.

FIG. 4 is a block diagram showing the configuration of the control system, in which 31 is a setting section for the lowering position and raising position of the ram 14, 32A32B
3 is an addition counter and a subtraction counter that count the A-phase and B-phase pulse data of the low reencoder 24;
3 is an arithmetic control unit that calculates the command value from the setting unit 31 and the count pulses from the addition counter 32^ and the subtraction counter 32B; This is a servo motor driver that drives the servo motor 2 based on position feedback pulses.

In addition, in this embodiment, as the low reencoder 19,
An incremental encoder is used to count phases A and B separately.

Incidentally, in order to generate a pressing force using a positioning servo, the position is set to exceed the bottom dead center of the mold and the mold is lowered. However, at this time, the amount of return increase is unknown, so as a countermeasure, (1) a deceleration point sensor is provided near the top dead center, and high-speed return to the 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 the absolute encoder.

etc. are possible.

In method (2), it takes time to return and the indexing time of the device becomes longer. Method (2) improves the index time, but increases the cost.

Therefore, in this embodiment, A of the incremental encoder is
By counting the phase and B phase separately, even when vibration occurs, such as reciprocating the encoder slit at the bottom dead center due to the reaction force of the mold, etc., when pressurizing at the bottom dead center, a considerable amount of vibration can occur. A circuit has been added that can maintain the current position with precision. This counter data is taken in by the control unit, and after calculation, the return amount is determined. However, even if the above knee count is performed, there is an error of ±1 pulse, so high-speed positioning is performed using an amount 10 pulses less than that drop. The next step is to adjust the origin.

By doing this, it is possible to perform accurate operations every time at low cost without significantly affecting index time.

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

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

Step 100. Clear the servo count. Specifically, an addition counter 32^1, a subtraction counter 32B, an arithmetic control section 33. Each count value of the servo motor driver 34 is cleared to 0.

Step 110: Start reading motor feedback pulse counts.

Step 120: The servo motor 2 is driven according to the data set in advance on the operation panel to start lowering the ram 14 and perform a press operation. The settings include travel distance + offset, acceleration/deceleration points, and associated speed settings.

Step 130 Sample and link pulses corresponding to the downward command movement amount given to the servo driver.

Step 140: The target deceleration point set on the W operation panel is compared with the commanded movement amount. That is, it is determined how much of the commanded movement amount has currently been issued and whether that amount has reached the target deceleration point.

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

Step 160: The servo driver waits for a positioning completion signal of the movement distance - offset - movement distance to be output for the movement distance set on the W operation panel.

Step 170: After the positioning is completed, the stroke end is physically reached (from the mold stopper, etc.), but the motor attempts to rotate by the amount of offset, and the motor generates maximum torque. This step limits the motor torque.

Step 180 The state of step 170 is maintained for the time set on the operation panel.

In step 190, the offset amount in step 170 is cleared to 0. (Completion of pressurization) Step 200: Read the motor position with the acceleration/deceleration counter.

Step 2 In order to ensure the operation of the 10° motor, 1.
Offset to minus by 0 pulse (approximately 0.01 m) and use it as an upward movement command.

Step 220゛Motor rises.

Step 230 The same operation as step 130 is performed.

Step 240 Target acceleration set by the operation panel (
Compare and judge points (points and sampling data).

Step 250: Change the acceleration speed to the one set on the W operation panel.

Step 260. Step 270: The motor returns to the home position by a negative offset distance at the home speed.

Step 280; After detecting the two phases of the motor, the motor is stopped.

〔Effect of the invention〕

As explained above, according to the present invention, the following effects are achieved.

■The shape of the press equipment can be made smaller.

■The noise generated by the press equipment can be suppressed.

■Impact force and impact noise when the mold stopper collides can be suppressed.

■With simple settings, you can set the optimal pressing condition for the workpiece.

[Brief explanation of drawings]

Fig. 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 the link section, Fig. 4 is a block diagram showing the configuration of the control system, and Fig. 5 is a concrete diagram. 3 is a flowchart showing a typical control example. 1: Case 2: Servo motor 4: Operation panel 52 Ball screw shaft 5a: Right-hand screw
5b: Left thread 6.7: Bearing 8: Right nut 9: Left nut 10: Linear bearing 11: Shaft
12: Right link I3: Left link
14: Ram 15: Pivot 16. 17: Bully 18: Timing belt 19: Rotor encoder 20: Oil run rule 2I; Detection arm 22: Detection rod 23: Photo sensor 24° electromagnetic brake 31: Setting section 32A; Addition counter 32B
: Subtraction counter 33; Arithmetic control unit 34 Servo motor driver

Claims (1)

[Claims] 1. A ball screw shaft that is rotationally driven by a servo motor and has a right-hand thread and a left-hand thread from its longitudinal center portion, and a right-hand nut and a left-hand nut that are screwed into the right-hand thread and left-hand thread of the ball screw shaft, respectively; A press consisting of a pair of links whose tips are rotatably fixed to these right nuts and left nuts, whose base ends are rotatably fixed to the upper end of the ram, and a ram supported vertically so that it can be raised and lowered. Device.