JP2003010919A - Clamping unit for plate material bending machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a desirable clamping unit for a plate material bending machine for use by inserting a special bending die between an upper die and a bottom die in addition to conventional bending work, and for executing offset bending work. SOLUTION: The rear end portion of an upper frame is pivoted to the rear end portion of a bottom frame so that the front end portion of the upper frame can be opened and closed vertically; top ends of a pair of arcuate elastic arms provided from side to side are supported on the displacement portion of a crank mechanism provided horizontally in the upper frame; the bottom end of the arcuate elastic arm is supported by supporting point axis having an eccentricity mechanism provided in the bottom frame; and the upper die is provided by interlocking the bottom end to the upper end of the arcuate elastic arm; and the bottom die is provided in the bottom frame in compliance with the position of the upper die.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a clamp device for a plate bending machine, and in particular, it is used by inserting a special bending die between an upper die and a lower die in addition to the ordinary bending work. In this case, the present invention also relates to a clamp device for a plate bending machine that excels in clampability of the plate material and is also suitable for offset bending.

[0002]

2. Description of the Related Art As a conventional plate bending machine, as shown in FIG. 6, an upper frame having a rear end axially supported by a rear end so that the front end can be opened and closed above the lower frame supporting the whole. Is provided. A crank mechanism is provided on the upper frame, and a horizontal eccentric shaft 121 is connected to a driving device 122 such as a servomotor. The crank mechanism is located on the left and right of the upper frame.
The upper end of the (connecting arm) is connected, and the lower end of the bow-shaped elastic arm is pivotally supported by a fulcrum shaft provided on the lower frame. The upper die 1 is attached integrally to the lower end of the lower frame, the plate support plate 5 is provided integrally with the lower frame at the front of the lower frame, and the lower die 2 is attached to the upper end of the plate support plate 5. Has been.

With such a structure, when the eccentric shaft is rotated by a driving device such as a servomotor, the upper end of the bow-shaped elastic arm is pivotally supported by the displacement portion of the eccentric shaft. When the bow-shaped elastic arm swings up and down with the fulcrum shaft of the lower frame as the fulcrum, the upper mold attached to the upper frame via the plate pressing plate moves up and down, and when the bow-shaped elastic arm reaches the top dead center, The plate material is clamped between the lower mold and the lower mold attached to the lower frame via the plate supporting plate by elastic force.

Further, inside the upper frame and the lower frame, there are provided vent beams 6 for bending the plate material clamped by the upper mold and the lower mold in forward and reverse directions.

As described above, since the upper frame and the lower frame are connected to the arcuate elastic arm (connecting arm) via the eccentric shaft, during normal bending,
The top dead center and the bottom dead center of the crank mechanism are set so that the clamping force on the plate material is maximized.

However, in order to cope with various bending processes, the special bending mold 3 may be inserted and mounted between the upper mold and the lower mold for bending. In this case, the top dead center is displaced by the thickness of the special bending die, and the clamping force is reduced. Therefore, conventionally, in order to adjust the displacement of the thickness of the special bending die, as shown in FIG. As shown, if the special bending die is not installed, the lower lock spacer S
When 2 is inserted and a special bending die is attached,
A method of adjusting the displacement position by removing the lower lock spacer and inserting the upper lock spacer S1 in the upper part of the eccentric shaft instead of the lower lock spacer has been adopted. In an actual bending machine, the lock spacer is inserted and removed by a fluid cylinder or the like in a direction parallel to the axis, but in FIG. 5, the lock spacer is shown in the front-back direction for the sake of convenience.

However, in such a system, a device for inserting and removing the upper and lower lock spacers is required, the structure is complicated, the switching time is long, the equipment is expensive, and the productivity is poor. Furthermore, due to the variety of bending of plate materials, there has been a case where a so-called offset bending in which the center of the plate material is shifted to the left or right with respect to the machine center is required to be bent. Since it is not possible to independently adjust the displacement of the bow-shaped elastic arm, it has not been possible to sufficiently cope with such offset bending.

[0008]

SUMMARY OF THE INVENTION In view of the above situation, the present invention is directed to a case where a special bending die is inserted between the upper die and the lower die in addition to the ordinary bending work, and the offset bending is used. An object of the present invention is to provide a suitable clamp device for a plate bending machine in processing.

[0009]

The invention according to claim 1 is
The rear end of the upper frame is pivotally attached to the rear end of the lower frame so that the front end of the upper frame can be opened and closed vertically. The upper end of the pair of bow-shaped elastic arms provided is pivotally supported, the lower end of the bow-shaped arm is pivotally supported by a fulcrum shaft having an eccentric mechanism provided in the lower claim, and an upper die is provided in conjunction with the upper end of the bow-shaped elastic arms. The lower mold was provided on the lower frame corresponding to the position of the upper mold.

As described above, the eccentric mechanism for rotating the fulcrum shaft by the driving means such as the servo motor is provided on the fulcrum shaft of the lower frame which rotatably supports the lower end of the arcuate elastic arm, and the displacement of the fulcrum shaft can be adjusted up and down. When clamping and bending a plate material using an ordinary mold, the fulcrum shaft is displaced to the lower position, and a special bending mold is inserted between the upper mold and the lower mold to bend it. In the case of machining, it is possible to rotate the eccentric shaft and to displace the fulcrum shaft upward by the thickness of the special bending die.

According to a second aspect of the present invention, in the first aspect of the present invention, fulcrum shafts pivotally supported at the lower ends of the left and right bow-shaped elastic arms are provided with independent eccentric shafts, and fulcrum points are provided by driving means such as servomotors. The height of displacement of the shaft can be freely adjusted to the left and right, and the fulcrum shafts connected to the lower ends of the left and right bow-shaped elastic arms are fulcrum shafts with independent eccentric mechanisms.

As a result, the clamping force of the plate material can be adjusted independently on the left and right, and it is possible to make adjustments corresponding to delicate bending adjustment and offset bending of the plate material.

According to a third aspect of the present invention, the left and right fulcrum shafts of the lower frame are connected by a single drive shaft, and a left and right clamping force is adjustable by interposing a phase adjusting mechanism therebetween. A fulcrum shaft is independently provided at the lower ends of the left and right bow-shaped elastic arms, and the left and right fulcrum shafts are connected by a single eccentric shaft via a phase adjusting mechanism. As a result, when the phase adjustment mechanism is normally locked and the fulcrum shaft is displaced up and down by interlocking with the left and right, the phase adjustment mechanism works when it is desired to provide a difference between the left and right clamping forces.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a side view of a bending machine for plates and the like to which the clamp device according to the present invention is applied, and FIG. 2 is a mechanism for vertically swinging a bow-shaped elastic arm and displacing a fulcrum shaft at a lower end. The figure is shown. An upper frame 20 is pivotally supported 30 at a rear end portion on an upper portion of a lower frame 10 which supports the whole, and a front end portion of the upper frame can be opened and closed vertically. An upper eccentric shaft 21 is provided above the front portion of the upper frame in parallel with the opening / closing fulcrum shaft 30 of the upper frame, and is rotatable by an upper driving means 22 such as a servo motor. Displacement portions 23a and 23b are provided on the left and right sides of the upper eccentric shaft, and arcuate elastic arms (connecting arms) 40a and 4a are provided at these portions.
Upper mounting holes 4 provided in the upper end portions 41a and 41b of
Axial support is provided via 2a and 42b. On the other hand, it is pivotally supported by lower fulcrum shafts 11a and 11b provided on the lower frame via lower mounting holes 44a and 44b provided at lower ends 43a and 43b of the bow-shaped elastic frame.

A plate pressing plate 4 is provided at the front part of the upper frame, an upper mold 1 is attached to the lower end thereof, a plate supporting plate 5 is provided at the front part of the lower frame, and a lower mold is provided at the upper end thereof. When the upper eccentric shaft 21 is rotated as shown in FIG. 1 when it is mounted and normally bent, the bow-shaped elastic arm is pivotally supported at the displacement portion, so that the upper frame swings up and down and the bow-shaped elastic arm top-dead. The plate material used for bending is clamped between the upper mold 1 and the lower mold 2 by the elastic force when the point is reached.

As shown in FIG. 1 (b), the upper frame is opened and a special bending die is mounted under the upper die for the usual bending clamp described above, and the bending is performed differently from the ordinary bending. In this case, the top dead center of the bow-shaped elastic arm is displaced by the thickness of the special bending die. (Note that the special bending die is attached or detached by a slide arm or the like, but is omitted in FIG. 1.) Therefore, the lower fulcrum shafts 11a and 11b of the bow-shaped elastic arm provided on the lower frame are attached. An eccentric mechanism is provided. An example of this eccentric mechanism will be described with reference to FIG. 2. Left and right arm lower brackets 14a and 14b of the lower frame.
The lower end of the arcuate elastic arm is pivotally supported by the lower eccentric shafts 11a and 11b, and the eccentric shaft is rotated by the lower drive means 12a and 12b such as a servomotor via the drive gears 13a and 13b. The elastic arm lower fulcrum shaft was displaced vertically. The conventional upper eccentric shaft requires a larger eccentric shaft and a driving means such as a servomotor with a larger capacity in order to increase the stroke by the thickness of the special bending die in addition to the displacement of the opening / closing stroke of the upper frame. However, it is sufficient to displace the lower fulcrum shaft up and down by this amount by a driving means having a small eccentric shaft and a small capacity.

Further, as shown in FIG. 2, when the lower eccentric mechanisms are independently provided on the left and right bow-shaped elastic arms, the displacement can be adjusted independently on the left and right, and as a result, a difference is provided between the left and right clamping forces. You can

As another application example of the lower eccentric mechanism, as shown in FIG. 3, the lower eccentric shafts 11a and 11b attached to the left and right arm brackets 14a and 14b and the drive gear 13a,
13b are respectively connected, and the left and right drive gears are connected by a single connecting drive shaft 18 via a phase adjusting mechanism 17. An example of the phase mechanism will now be described with reference to FIG. 4. An elliptical gear flexspline 17b is arranged inside the circular spline 17a so that it meshes with the major diameter portion and is completely free with the minor diameter portion, and the number of teeth is circular. The splines are about two more than the flex splines, and when the wave generator 17c makes one rotation through the cam, the phase shifts from the circular splines by the number of teeth. In this way, the configuration through the phase adjusting mechanism shown in FIG. 3 is adopted, and normally, the phase adjusting mechanism 17 is locked and the first lower drive means 15 synchronizes the left and right to adjust the fulcrum displacement, and the left and right sides are adjusted. When it is desired to provide a difference in the clamping force, the phase adjusting drive means 16 is operated.

[0019]

When a special bending die is used by inserting it between the upper die and the lower die used for clamping the plate material during the normal bending process, it is connected to the lower die provided on the lower frame. By having a mechanism that vertically displaces the fulcrum shaft,
The upper and lower lock spacers and their insertion / removal devices provided on the conventional upper frame are no longer required, the mechanism of the clamp device is simplified, and the die switching adjustment can be performed in a short time, and the equipment is inexpensive. And productivity is improved.

Further, when the conventional upper frame is provided with a displacement mechanism, the displacement of the eccentric shaft is increased because the opening / closing stroke of the upper frame is also combined, and the drive device such as a servo motor is also increased. Since the vertical displacement of the fulcrum shaft of the lower frame is required only for the thickness of the special mold, it is possible with a driving device having a small capacity.

Further, according to the second aspect of the invention, the clamping force can be adjusted independently for each of the left and right sides.
It is possible to make fine adjustments according to the plate thickness and bending usage, and it can also be used when offset clamping and other clamping forces are desired to be provided on the left and right. Further, according to the invention of claim 3,
Since there is one drive shaft that displaces the left and right fulcrum shafts, and the phase adjustment mechanism is provided between them, it is possible to adjust the left and right clamping forces while synchronizing the displacements of the left and right fulcrum shafts.

[Brief description of drawings]

FIG. 1 shows a side view of a bending machine to which a clamp device according to the present invention is applied.

FIG. 2 shows a mounting structure of a bow-shaped elastic arm.

FIG. 3 shows another example of a lower eccentric shaft configuration.

FIG. 4 shows a principle diagram of a phase adjusting mechanism.

FIG. 5 shows an example of a conventional clamping device.

FIG. 6 shows an example of a plate bending machine using a conventional clamp device.

[Explanation of symbols]

1 Upper mold 2 Lower mold 3 Special bending mold 4 Plate holder plate 5 Plate support plate 6 Bent beam 10 Lower frame 11a, 11b Lower eccentric shaft 12a, 12b Lower drive means 13a, 13b drive gear 14a, 14b Arm lower bracket 15 First lower drive means 16 Phase adjustment drive means 17 Phase adjustment mechanism 17a Circular spline 17b flex spline 17c Wave Generator 20 upper frame 21 Upper eccentric shaft 22 Upper drive means 23a, 23b Upper displacement part 30 frame fulcrum axis 40a, 40b Bow-shaped elastic arm 41a, 41b Upper end of bow-shaped elastic arm 42a, 42b Attachment hole for upper end of bow-shaped elastic arm 43a, 43b Bow-shaped elastic arm lower end 44a, 44b Bow-shaped elastic arm lower end mounting hole S1 Upper lock spacer S2 Lower lock spacer

Claims (3)

[Claims] 1. A crank mechanism horizontally mounted on the upper frame, wherein the rear end of the upper frame is pivotally attached to the rear end of the lower frame so that the front end of the upper frame can be opened and closed vertically. The displacement part pivotally supports the upper ends of a pair of left and right arcuate elastic arms, and the lower end of the arcuate arms is pivotally supported by a fulcrum shaft having an eccentric mechanism provided on the lower frame, and is interlocked with the upper ends of the arcuate elastic arms. An upper die is provided on the lower frame so that a lower die is provided on the lower frame so as to correspond to the position of the upper die. 2. A clamp device for a plate bending machine according to claim 1, wherein the fulcrum shafts connected to the lower ends of the left and right bow-shaped elastic arms are fulcrum shafts having independent eccentric mechanisms. 3. The plate bending according to claim 1, wherein fulcrum shafts are independently provided at the lower ends of the left and right arcuate elastic arms, and the left and right fulcrum shafts are connected by a single drive shaft via a phase adjusting mechanism. Clamping device for processing machine.