JPH10314998A - Press working method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a press working method to enable precision working by reducing impact force on colliding at a work so as to reduce breakthrough, to increase a die life by reducing wear/breaking of a punch and to reduce working noise and vibration by extremely reducing impact noise at the time of particularly conducting bottoming, coining or drawing, etc. SOLUTION: This working method is to control, when descending a slide of a press machine from a top dead center position to a bottom dead center position so as to extremely slowly descend the slide near the bottom dead center and rapidly from the bottom dead center neighborhood to the bottom dead center position. Accordingly, a process curve is formed so as to protrude downward from the bottom dead center neighborhood to the bottom dead center position. Further, the slide is driven by a servo motor, a linear motor as well as a cam means, etc.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pressing method, and more particularly to a pressing method suitable for forming a gentle curve near the bottom dead center, such as pressing, coining or drawing. About.

[0002]

2. Description of the Related Art Generally, when a metal material is subjected to shearing processing, a reciprocating motion of a slide is often driven at a high speed by rotation of a crankshaft. In this case, FIG.
As shown in the curve A1, the slide process curve is formed to be a sine curve from the top dead center position to the bottom dead center position. However, in the case of performing a process of forming a gentle curve near the bottom dead center, for example, pressing, coining, or drawing, it is conventionally advantageous to drive the slide by a link mechanism or a cam. As shown by curve B1 in FIG. 5, the process curve in the case of driving by the link mechanism has a short time of 90 ° before and after the slide top dead center position (work transfer step), and has the bottom dead center position. And the time between 90 ° before and after (processing step) is long.
When driven by a cam, the process curve is freely formed depending on the shape of the cam. Generally, a curve substantially similar to that of the link mechanism is formed.

[0003]

However, in the conventional processing method, the slide speed at the bottom dead center position can be reduced, for example, when performing precision processing or when processing a thin metal material or non-metal material. However, since the slide descent speed from the top dead center position to the bottom dead center position is formed by a continuous curve, the impact force at the moment of colliding with the material is not small. Since this impact causes a breakthrough peculiar to the press machine, it affects the processing accuracy particularly when precision processing is performed. Further, not only wear and breakage of the punch are likely to occur, but also processing noise and vibration are increased.
Further, in the case of performing precision machining, even a slight flaw affects the precision, so that it is necessary to minimize the occurrence of material flaws due to the impact force.

The present invention has been made to solve the above-mentioned problems, and in particular, when a thin material or a nonmetallic material is precisely pressed, the impact speed of a punch is made slower than before.
Provide a press working method that reduces breakthroughs by drastically reducing the impact force, and further reduces punch wear and breakage, processing noise and vibration, and material damage. The purpose is to do.

[0005]

In the press working method according to the present invention, the following method is performed to solve the above-mentioned problems. That is, a press working method for working a work by reciprocating an upper mold mounted on a slide toward and away from a lower mold mounted on a bed, wherein a process curve of the slide is lower. This is a method characterized by being controlled to protrude downward near the dead center.

Further, the press working method of the present invention is a press working method for working a work by reciprocating an upper die mounted on a slide toward and away from a lower die mounted on a bed. Then, after the slide is operated very slowly near the bottom dead center, the slide is controlled to rapidly descend toward the bottom dead center position.

Further, the slide may be reciprocated by a servomotor.

[0008] The slide may be reciprocated by a linear motor.

The slide may be reciprocated by a cam means.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 shows a process curve of a slide in which the slide passes from the top dead center position to the bottom dead center position and moves again to the top dead center position, and shows the slide position with respect to the crank angle of the press. This is indicated by a graph. A curve A is usually based on a process curve (referred to as a crank curve) by rotational driving by a crankshaft, and a curve B is based on a process curve (referred to as a link curve) of a slide driven by a normal link mechanism. Is shown. In the case of the curve A, the slide descends at a relatively slow speed near the top dead center (crank angle 0 °) and gradually increases in speed while passing through the intermediate position (crank angle 90 °), and then gradually slows down after a while. I will descend. Thereafter, in the vicinity of the bottom dead center (around the crank angle of about 150 ° to 170 °), the descent speed becomes extremely slow (it appears to be stopped visually). Then, it descends suddenly from around 170 ° of the crank angle and reaches the bottom dead center. After that, it rises to around 190 ° of the crank angle, rises very slowly to around 220 ° of the crank angle, gradually rises gradually after passing the intermediate position (crank angle of 270 °) while gradually increasing the speed, and then reaches the top dead center. In front (around a crank angle of 330 °), the speed becomes slower again and reaches the top dead center position.

Therefore, the slide movement curve is formed so as to draw a substantially sine curve at a position except the vicinity of the bottom dead center and to protrude downward from the vicinity of the bottom dead center to the bottom dead center position.

When the link curve is used as the base as shown by the curve B in FIG. 1, the slow speed near the bottom dead center starts earlier than the curve A, and the slow time is longer than the middle speed (the crank angle). The speed increases from around 270 ° to near the top dead center, and reaches the top dead center at a slow speed again.The rapid fall from the bottom dead center to the bottom dead center is almost the same as curve A. is there.

Comparing the relationship with the work, the work is fed by the feed device while rotating from the slide up position (crank angle of about 270 ° to 90 °). Stop moving, slide near bottom dead center (crank angle 150 ° ~
While descending very slowly at 170 °), for example, the work is held down by a stripper, or the work is positioned by a pin. In the case of drawing, the work is pressed down. The stripper or wrinkle is pressed by the upper die at the portion where the work is processed. During this time, the slide is lowered very slowly, so that the impact force with the work is extremely small. The work is processed at a crank angle of about 170 to 190 degrees. For this processing, for example, pressing processing, coining processing, or drawing processing is suitable. Further, a non-metallic material such as a thin metal material (with a plate pressure of 0.1 mm or less) or plastic, or a relatively thick metal material in the case of drawing is used as the work. At the time of processing the workpiece, the slide is temporarily stopped at the position of the slide before processing (around a crank angle of 170 °), so that the impact force on the workpiece is small and the processing noise is extremely low.

The processing curve of the slide is not limited to the curves A and B. The slide is operated in a state where the slide is temporarily stopped near the bottom dead center, and suddenly descends from the vicinity of the bottom dead center to the bottom dead center position. If it is a curve, the shape of the curve can be set freely.

Next, a description will be given of a driving device of a press machine for forming the above-mentioned slide process curve with reference to FIGS.

FIG. 2 shows an embodiment in which the slide is driven by a servomotor. The slide 1 is guided by a guide portion 2a provided on a frame 2 (not shown).
The screw part 1a is formed in the upper part. Meanwhile, frame 2
A ball screw 5 is attached to the servomotor 4 supported by the slider 1, and the ball screw 5 is screwed to the screw portion 1 a of the slide 1. Accordingly, the ball screw 5 is rotated by the operation of the servo motor 4, and the slide 1 can reciprocate up and down while being guided by the guide portion 2a, so that the work is processed by the upper die 6 attached to the lower surface of the slide. .

Since a program for setting the curve A or curve B of the slide 1 as shown in FIG. 1 can be input to the servomotor 4 in advance, the speed can be changed or the motor can be rotated in the reverse direction by the program. It can be done very easily.

Various forms of driving the slide of the press by a servomotor have been proposed, and the configuration is not limited to the above, and any of the forms can form the above curve.

In still another embodiment, in a conventional press using a crankshaft, the crankshaft may be driven to rotate by a servomotor.

FIG. 3 shows a form in which the slide is driven by a linear motor. The frame has a frame 21 having a column 22 and a slide 25 which is vertically movable within the column 22. A link mechanism 30 connected to the slide 25 from the top of the column 22;
And a linear motor 40 attached to the motor. The slide 25 is a guide portion 22a of the column 22.
Slidably guided. An upper die 28 is attached to the lower surface of the slide, and reciprocates so as to approach and separate from a lower die disposed on a bed (not shown) via a bolster.

The link mechanism 30 includes a first link 32 pivotally connected to the upper projection 22b of the frame 21 by a shaft 31.
And a second link 34 pivotally connected to the projection 25a of the slide 25 with a shaft 33, and the first link 32 and the second link 34 are formed in a shape that can be pivotally connected with a shaft 35. The first link 32 and the second link 34
2b and 25a are provided two by two.

The linear motor 40 includes a stator 41 having an electromagnet and a coil body 44 as a moving element. The coil body 44 is disposed so as to be movable with respect to the stator 41. Then, the coil body 44 is directly attached to the first link 32, and the stator 41 is attached to the column 22, so that the first link 32 is driven to swing about the shaft 31, and the second link 34 is The slide 25 and the upper die 28 are reciprocally movable by being driven to swing around the center 33.

The form in which the above-described linear motor is used is not limited to the above, and the linear motor may be directly mounted on the side surface of the slide, and the linear motor has a fixed sheet and a movable member. If so, any commercially available linear motor may be used.

Since a program for setting the curve A or the curve B of the slide 1 as shown in FIG. 1 can be input to the linear motor 40 in advance, the speed can be changed or the motor can be rotated in the reverse direction by the program. It can be done very easily.

FIG. 4 shows an embodiment in which the slide is driven by a cam mechanism, and shows a die-type press. Four guide posts 5 from the inside of the frame 51
6 is provided so as to extend upward and outside the frame 51. A bolster 54 is fixed to the upper surface of the frame 51, and a lower mold 61 is attached to the upper surface of the bolster 54. A slide 55 is fixed to the upper part of each guide post 56 so as to connect the respective guide posts 56, and an upper die 62 is attached to the lower surface of the slide 55, and reciprocates so as to approach and separate from the lower die 61. Is done. Further, the guide post 56 is guided by guide portions 57 provided at the upper and lower portions of the frame 51 and reciprocated vertically. A connecting member 58 is fixed inside the frame 51 so as to connect the respective guide posts 56, and a cam follower 63 is attached to an upper portion of the connecting member 58. On the other hand, the cam 64 is rotatably supported by the frame 51, and the cam surface is arranged so as to be able to contact the cam follower 63. Further, a spring means 65 for urging the connecting member 58 upward is disposed below the connecting member 58.
Accordingly, the rotation of the cam 64 causes the connecting member 58 to reciprocate up and down by the stroke via the cam follower 63, and the slide 55 reciprocates up and down accordingly, whereby the workpiece is processed by the upper die 62 and the lower die 61. Will be.

The cam surface can be formed in advance on the cam 64 so that the slide process curve in FIG. Therefore, the predetermined movement of the slide can be achieved by rotating the cam, and the slide can be moved at a high speed.

It should be noted that the cam can be arranged above the slide instead of the above-mentioned die-pressing machine.

As described above, the slide driving means of the press for forming the process curve of the slide into the curve A or the curve B can be performed by various means. Further, the slide driving unit is not limited to the above-described embodiment, and may be any of generally proposed units.

[0030]

According to the present invention, a method for processing a press machine processes a work by reciprocating an upper die mounted on a slide toward and away from a lower die mounted on a bed. The process curve of the slide is controlled so as to protrude downward near the bottom dead center. Therefore, when the slide descends from the top dead center to the bottom dead center position, it descends at an extremely slow speed just before colliding with the work, and then descends rapidly until the bottom dead center position is reached to process the work. As a result, the impact of the punch on the workpiece is small and breakthroughs and damage to the workpiece can be reduced, and the wear and breakage of the punch can be reduced, enabling precision machining and extending the life of the mold. Can be. Further, processing noise and vibration can be reduced, which is useful for improving the environment. Therefore,
This is advantageous for precise pressing, coining, or drawing.

Further, in this working method, the slide is controlled to move very slowly near the bottom dead center and then rapidly descend toward the bottom dead center position. When descending to the dead center position, it descends at a gentle speed just before colliding with the work, and then descends rapidly until it reaches the bottom dead center position for processing the work. Therefore, punch impact force on the work is small, breakthroughs and work scratches can be reduced, and punch wear and damage can be reduced.
It enables precision machining and prolongs the mold life. Further, processing noise and vibration can be reduced, which is useful for improving the environment.

If the reciprocating movement of the slide is driven by a servomotor or a linear motor, a process curve can be formed at an arbitrary timing and a press machine can be manufactured with a very simple structure.

Further, when the reciprocating movement of the slide is driven by the cam means, the timing can be freely set and the slide can be moved at high speed.

[Brief description of the drawings]

FIG. 1 is a graph showing a process curve of a slide according to one embodiment of the present invention.

FIG. 2 is a simplified diagram showing a form in which a slide is driven by a servomotor to form the process curve of FIG. 1;

FIG. 3 is a simplified diagram showing a form in which a slide is driven by the linear motor.

FIG. 4 is a simplified diagram showing an embodiment in which a slide is driven by the cam means.

FIG. 5 is a graph showing a process curve of a conventional slide.

[Explanation of symbols]

 1, 25, 55 ... slide 2, 21, 51 ... frame 4 ... servo motor 5 ... ball screw 6, 28, 62 ... upper die 40 ... linear motor 61 ... lower die 63 ... cam follower (cam means) 64 ... cam (cam) Means) A, B: slide process curve

──────────────────────────────────────────────────続 き Continued on front page (51) Int.Cl. ⁶ Identification code FI B30B 15/28 B30B 15/28 C

Claims (5)

[Claims] 1. A press working method for processing a work by reciprocating an upper die mounted on a slide toward and away from a lower die mounted on a bed, wherein a process curve of the slide is provided. Is controlled to protrude downward near the bottom dead center. 2. A press working method for working a workpiece by reciprocating an upper mold mounted on a slide toward and away from a lower mold mounted on a bed, wherein the slide has a lower die. A press working method characterized in that it is controlled to move very slowly near a point and then rapidly descend toward a bottom dead center position. 3. The press working method according to claim 1, wherein the reciprocating movement of the slide is driven by a servomotor. 4. The press working method according to claim 1, wherein the reciprocating movement of the slide is driven by a linear motor. 5. The press working method according to claim 1, wherein the reciprocating movement of the slide is driven by cam means.