JPH07304000A - Press machine - Google Patents

Abstract

(57) [Summary] [Purpose] To provide a press machine capable of detecting overload by providing an overload protector at one position for a plurality of points. [Structure] Crown 2 provided on the top of press body 1
In a press machine provided with a slide drive device 6 for driving the slide 5 up and down, the slide drive device 6 is composed of a reciprocating drive means and a link mechanism 8, and a connecting portion between the reciprocating drive means and the link mechanism 8 is provided. With the overload protector 12 provided, just by providing the overload protector 12 at one position for a plurality of points,
It becomes possible to protect the press machine from overload.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a press machine equipped with an overload protector.

[0002]

2. Description of the Related Art Conventionally, most press machines are provided with a slide drive mechanism on the upper part of the press body. By driving the slide up and down by this slide drive mechanism, the upper die attached to the lower surface of the slide, the bed or It is configured to perform press molding between lower molds fixed on the bolster. Also, for the slide drive mechanism, one that uses a crank mechanism consisting of a crank shaft and connecting rod,
There is a machine using a link mechanism, and a press machine using the link mechanism is disclosed in, for example, JP-A-57-146.
497, JP-A-2-28437, JP-A-6
It is publicly known, for example, in Japanese Patent Publication No. 3-111295.

In the former two publications, the vertical movement of the plunger is transmitted to a slide (a receiving plate) by a link mechanism composed of rocking arms and counterbalance arms which are symmetrically arranged, and the slide is driven up and down. In the latter publication, the operating rods arranged in a V-shape are connected by the connecting rods between the sliding rods that are vertically moved by being guided by the guides. The slide rod is driven up and down via the. However, none of the press machines is provided with measures against overload, so that when overload occurs during press molding, a problem such as damage to the link mechanism due to overload occurs. In order to prevent such a problem, a press machine has been proposed in which an overload protector is provided to protect the slide drive mechanism, the mold, and the like from overload. For example, JP-A-53-
16938, etc.

[0004]

However, in the conventional press machine, since the overload protector is provided at the point where the driving force of the slide drive mechanism is transmitted to the slide, the point is the same as in the press machine employing the link mechanism. If there are a plurality of points, an overload protector must be installed at each point, which is expensive. Also, if overload protectors are installed at multiple points, if an eccentric load acts on the slide, the overload protector may work even below the molding load.Therefore, press molding with eccentric load cannot be performed. There was a problem such as receiving. The present invention has been made in order to improve such a problem, and an object of the present invention is to provide a press machine capable of detecting an overload by providing an overload protector at one position for a plurality of points. Is.

[0005]

In order to achieve the above-mentioned object, the present invention provides a press machine, wherein a crown provided at an upper portion of a press body is provided with a slide drive device for vertically driving a slide. Is composed of a reciprocating drive means and a link mechanism, and an overload protector is provided at a connecting portion between the reciprocating drive means and the link mechanism. In addition, a die height adjusting mechanism is provided at the swing fulcrum of the swing lever that constitutes the link mechanism.

[0006]

[Operation] With the above configuration, even if there are multiple points, it is sufficient to provide an overload protector at one location, so the response is good, and even if an eccentric load acts, the overload that acts before reaching the forming load is reached. Since there is no load protector, the slide will not tilt. In addition, the die height adjustment mechanism makes it easy to adjust the die height when changing the mold.

[0007]

Embodiment An embodiment of the present invention will be described in detail with reference to the drawings. 1 is a plan view of the press machine, and FIG. 2 is A- of FIG.
FIG. 3 is a sectional view taken along line A, and FIG. 3 is a sectional view taken along line BB in FIG. In these figures, 1 is a press body, and bed 1
The a and the upright 1b are integrally structured, and the crown 2 is placed between the upper ends of the upright 1b, and the crown 2 and the bed 1a are connected by the tie rod 3 inserted into the upright 1b. . Below the crown 2, there is provided a slide 5 which is vertically movable by being guided by a slide guide 4 provided on the upright 1b. The slide 5 is a slide drive device provided between the crown 2 and the slide 5. It is adapted to be vertically driven by 6.

The slide driving device 6 is composed of a crank mechanism 7 provided in the crown 2 and a link mechanism 8 provided below the crank mechanism 7. The crank mechanism 7
Has a crankshaft 7a, and the crankshaft 7a
A main gear 7b is connected to one end of the main gear 7b via a link 7h, and a pinion 7d provided on an input shaft 7c is meshed with the main gear 7b. The input shaft 7c is connected to a flywheel 10 via a clutch brake 9, and the flywheel 10 is driven by a main motor (not shown).
Is designed to be rotated.

Further, one end of a connecting rod 7f is connected to the eccentric portion 7e of the crankshaft 7a, and the other end of the connecting rod 7f is connected to a plunger 7g which is supported by the crown 2 so as to be vertically slidable. The plunger 7g is moved up and down via the connecting rod 7f in accordance with the rotation of the above, and the hydraulic chamber 12a of the overload protector 12 is provided in the plunger 7g. The hydraulic chamber 12a is a piston 12 housed in a plunger 7g.
It is divided by b, the other end of the connecting rod 7f is connected to the piston 12b through a ball joint 13, and a protector valve (not shown) is connected to the hydraulic chamber 12a. When the pressure exceeds a preset pressure, the protector valve allows the hydraulic pressure in the hydraulic chamber 12a to escape, thereby avoiding overload.

On the other hand, the link mechanism 8 has a pair of rocking levers 8a which are arranged symmetrically with respect to the center of the press body 1.
The inner ends of the swing levers 8a are connected to the lower portion of the plunger 7g by a first connecting link 8b arranged in a substantially V shape. A substantially middle portion of each rocking lever 8a is pivotally attached to a yoke 14a of a die height adjusting mechanism 14 which is symmetrically arranged via a pin 8c, and each rocking lever 8a is vertically moved around the pin 8c. In addition to being freely swingable, a dynamic balancer 15 and a balancer 16 composed of an air cylinder are attached to the outside of each swing lever 8a.

The first connecting link 8 of each swing lever 8a
The second connecting link 8d connects a substantially intermediate portion of the connecting portion between the b and the yoke 14a to the point 5a of the slide 5, and the slide 5 is driven up and down in accordance with the swing of the swing lever 8a. The height can be adjusted by a die height adjusting mechanism 14 according to a die (not shown). The die height adjusting mechanism 14 has a screw shaft 14b having a yoke 14a at its lower end, and a nut 14c is screwed to the screw shaft 14b. The nut 14c is rotatably supported by a nut receiver 14d fixed to the lower surface of the crown 2, and the nut 1c
A worm 14f is meshed with a worm wheel 14e formed on the outer peripheral surface of 4c. A drive source for die height adjustment (not shown) is connected to the worm 14f, and the nut 14c is rotated by the drive source for die height adjustment to rotate the nut 14a and the swing lever 8a. By changing the, the die height amount is adjusted.

To explain the operation, the flywheel 10 is constantly rotated by the main motor. When the clutch 9 is engaged in this state, the input shaft 7c is rotated and the crankshaft 7a is rotated through the pinion 7d and the main gear 7b.
Is rotated. The rotation of the crank shaft 7a lowers the plunger 7g via the connecting rod 7f, and the lowering of the plunger 7g lowers the slide 5 via the first connecting link 8b, the swing lever 8a and the second connecting link 8d. The outer end of the swing lever 8a is swung upward around the pin 8c, and the balancer 16 is simultaneously compressed. Further, as the slide 5 descends, the work is formed between the upper die attached to the lower surface of the slide and the lower die (both not shown) fixed on the bed 1a through the bolster 1c, and at the same time, the slide is moved. When 5 reaches the bottom dead center, the plunger 7g starts to rise, and accordingly, the slide 5 also starts to rise via the first connecting link 8b, the swing lever 8a and the second link 8d, and at the same time the balancer 16 extends. Then, the outer end side of the swing lever 8a is pushed down around the pin 8c, so that the slide 5 can be lifted to the top dead center with a smaller load in combination with the load of the dynamic balancer 15.

On the other hand, when an overload occurs during press molding and the pressure in the hydraulic chamber 12a of the overload protector 12 exceeds a preset pressure, the overload protector valve (not shown) is opened and the inside of the hydraulic chamber 12a is opened. Since the pressure is released, overload can be avoided. Further, when the die height amount is changed by exchanging the mold, the worm 14f and the worm wheel 1 of the die height adjusting mechanism 14 are changed.
The nut 14c is rotated via 4e. As a result, the yoke 14a moves up and down via the screw shaft 14b, and the pivot point of the yoke 14a and the swing lever 8a moves up and down. Therefore, the die height amount of the slide 5 can be freely adjusted according to the mold. You can

In the above embodiment, the reciprocating driving means provided in the slide driving device employs the crank mechanism 7 for converting the rotation of the main motor into reciprocating movement. A linear moving means such as a ball screw and a ball nut for converting into linear movement may be adopted.

[0015]

As described in detail above, the present invention comprises a slide drive device for vertically driving a slide, which comprises a reciprocating drive means and a link mechanism, and an overload protector is provided at a connecting portion between the reciprocating drive means and the link mechanism. Since it was set up,
Even if the link mechanism and the slide are connected via multiple points, only one overload protector needs to be provided. Therefore, compared to the conventional structure in which overload protectors are provided at multiple points, respectively. Can be provided easily and cheaply. Also, since there is only one overload protector, even in press molding where an eccentric load acts, the overload protector does not work before reaching the forming load due to the eccentric load, which causes the slide to tilt due to the eccentric load. In addition, since the responsiveness is good, the slide drive device, the mold, and the like are less likely to be damaged by the overload. Furthermore, the die height adjustment mechanism provided at the swing fulcrum of the swing lever allows easy die height adjustment when exchanging dies.
Since the distance from the rocking fulcrum of the rocking lever to the point is small, there is little deformation or thermal deformation with respect to the load, which enables high-precision molding. Since the dynamic balancer can be easily installed on the outer end of the lever, the number of parts can be reduced. Moreover, since the height of the upright can be lowered by providing the link mechanism between the crown and the slide, the rigidity of the press body can be improved and at the same time the press machine can be downsized.

[Brief description of drawings]

FIG. 1 is a plan view of a press machine according to an embodiment of the present invention.

FIG. 2 is a sectional view taken along the line AA of FIG.

3 is a cross-sectional view taken along the line BB of FIG.

[Explanation of symbols]

1 ... Press body, 2 ... Crown, 5 ... Slide, 6 ... Slide drive device, 8 ... Link mechanism, 8a ... Swing lever,
12 ... Overload protector, 14 ... Die height adjusting mechanism.

Claims (2)

[Claims] 1. A press machine comprising a crown (2) provided on an upper part of a press body (1) and a slide drive device (6) for vertically driving a slide (5), wherein the slide drive device (6) is provided. Is composed of a reciprocating drive means and a link mechanism (8), and an overload protector (12) is provided at a connecting portion between the reciprocating drive means and the link mechanism (8).
A press machine characterized by being provided with. 2. The press machine according to claim 1, wherein a die height adjusting mechanism (14) is provided at a swing fulcrum of a swing lever (8a) constituting the link mechanism (8).