JPH049640B2 - - Google Patents

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention connects a bed and a ram by a pair of pull links, and operates the pair of pull links synchronously by a single drive cylinder device. The present invention relates to a press device that eliminates a rigid frame by raising and lowering a ram, has high dynamic precision, and is resistant to eccentric loads.

[Conventional technology]

In recent years, demands for high processing accuracy and high productivity in press working have been increasing.

That is, multi-stage molds are frequently used due to robot automation and progressive feeding, and in order to cope with this, a highly rigid press that is resistant to eccentric loads and has high dynamic accuracy is desired. However, at present, a press having a structure that satisfies all of these requirements is large and expensive.

As a typical press frame, the 7th
There are C-shaped ones as shown in the figure and gate-shaped ones as shown in Fig. 8, both of which have rigid structures. A C-shaped frame has a lower pressing force and lower machining accuracy than a gate-shaped frame, so a gate-shaped frame is used for high-pressure-force, high-precision machining.

In either frame, when pressurizing force and its reaction force are applied during processing, the bed portion 52 and the crown portion 54 are deformed as shown by the two-dot chain line in the figure.

An upper mold and a lower mold are attached to the ram part 56 and the bed part 52, respectively, and the pressurizing force and its reaction force act as a bending moment on the bed part 52 and the ram part 56 during processing. As a result of the deformation of the bed portion 52 and the ram portion 56, the mold attached thereto is deformed. When the mold is deformed, processing accuracy decreases and its lifespan is shortened.

Here, among the deformations of the frame of the press, bending deformations caused by bending moments in particular have a negative effect on processing accuracy and mold life, so the bending deformations must be minimized as much as possible.

In order to reduce the bending deformation of a rigid frame, it is necessary to increase its rigidity. In order to increase the rigidity of the frame, it is necessary to increase the section modulus of the constituent members such as the bed section 52, crown section 54, and ram section 56, which make up the frame. It is most effective to raise the

By increasing the height of the bed portion 52, crown portion 54, and ram portion 56 that make up the frame, the overall height of the frame will increase, and if a large press is used, a pit must be dug and a part of the bed portion buried. It becomes impossible to install it in a factory building, and
The total weight of the press increases, and in addition to these problems, the bed portion 52, crown portion 54, and ram portion 5
It becomes difficult to maintain the horizontality and verticality of the large structure of the upright portion 6 and the upright portion 58 with high precision and strength, which leads to an increase in costs.

In addition, as shown in FIG. 9, a plurality of hydraulic cylinders 60 are attached to the crown portion 54 of the frame, and the ram portion 56 is raised and lowered by the plurality of hydraulic cylinders 60, thereby being resistant to eccentric loads. When trying to realize a multi-point hydraulic press,
A synchronization mechanism for synchronizing the operations of the plurality of hydraulic cylinders 60 is essential, and this synchronization mechanism is complicated and expensive.

Furthermore, as shown in FIG. 10, in a mechanical crank press, a crank rod 62 and a plunger 64 are connected by a connecting rod 66, and a ram portion 56 is attached to this plunger 64. year guide 68
The plunger guide 68 is designed to remove the horizontal component Px of the pressurizing force P to improve dynamic accuracy. However, if a mechanism is provided to remove the horizontal component of the pressing force using a plunger and a plunger guide, the press becomes larger and more expensive.

[Problem to be solved by the invention]

The present invention abandons the general concept of conventional presses using a rigid frame, connects the bed and ram by a pair of pull links, and connects the pair of pull links by a single drive cylinder device. The objective of this project was to produce an inexpensive, energy-saving press device that has a low overall height, high dynamic accuracy, and is resistant to eccentric loads by raising and lowering the rams in synchronized operation.

[Means to solve the problem]

The press device according to the present invention includes a bed, a ram disposed above the bed so as to be movable up and down via a guide part, and pull link support shafts located at symmetrical positions with respect to the bed centerline on both sides of the bed. a pair of pull links, the lower ends of which are pivotally connected via the pull link and the lever link at the lower end of the ram; The connecting portion is directly above the lever link support shaft,
In addition, these two links are pivotally connected to each other via a pivot shaft so that they are located symmetrically with respect to the bed center line, and when the rod of the drive cylinder device goes in and out, the lever link support shaft becomes the center. The cylinder body and rod of the drive cylinder device are pivotally connected to each lever link disposed on the side thereof, so that each lever link can rotate.

[Action of the invention]

When the rod of the drive cylinder device is moved in and out,
A pair of pull links placed on both sides of the bed synchronously reciprocate around the pull link support shaft, and a pair of lever links placed on both sides of the ram rotate around the lever link support shaft. The ram rotates reciprocally around the center synchronously, and as a result, the ram moves up and down while being guided by the guide section, and press working is performed continuously. In addition, at the lower end of the ram, the connection part between the pull link and the lever link is connected to the pull link support shaft that supports the pull link, the lever link support shaft that supports the lever link, and the pull link and lever link. Since this is a toggle mechanism in which the pivot shafts which are pivotally connected to the cylinder and the shaft are aligned in this order, the pressing force of the cylinder device becomes significantly large during press working.

〔Example〕

1 to 4 show a press apparatus according to a first embodiment of the present invention.

Pull link support shafts 4 are installed at symmetrical positions with respect to the bed center line C at the upper end of the bed 2, and each pull link 20 is attached to a portion of each pull link support shaft 4 that protrudes from both sides of the bed 2. The lower end is pivoted. In the press device of this embodiment, pull links 20 are arranged on the front and back sides of the bed 2, and two sets (pairs) of pull links 20 are arranged on both sides of the bed 2. It is located in A guide cylinder portion 6 is provided directly above each pull link support shaft 4 .

The upper half of the ram 8 has a hollow section 8a for housing the hydraulic cylinder device 10 and the lever link 12 therein.
are provided along the length direction. A guide rod 14 is provided at the lower end of the ram 8 at a position directly above the guide cylinder portion 6 of the bed 2,
Each guide rod 14 is fitted into a guide cylindrical portion 6 of the bed 2, and the ram 8 is moved up and down relative to the bed 2 while being guided by the guide cylindrical portion 6.

Lever link support shafts 16 are located directly above the pull link support shaft 4 at the upper end of the ram 8 and symmetrically with respect to the bed center line C.
is attached, and each lever link 12 housed in the hollow portion 8a of the ram 8 is pivotally connected to each lever link support shaft 16.

A hydraulic cylinder device 10 is installed almost horizontally in the hollow portion 8a of the ram 8, and a cylinder body 10a and a rod 10b of the hydraulic cylinder device 10 are pivoted to lever links 12 arranged on both sides of the hydraulic cylinder device 10. They are each pivotally connected via a mounting shaft 18. In this embodiment, the pivot shaft 18 is located below the lever link support shaft 16 at the lower end of the ram 8.

The upper end portions of the two pull links 20 and the lever link 12 are pivotally connected via a pivot shaft 22. This pivot shaft 22 is provided at the lower end of the ram 8, directly above the lever link support shaft 16, and at a position symmetrical with respect to the bed center line C.

In addition, in Fig. 1 and Fig. 2, 24, 26
indicate the upper and lower molds, respectively. FIG. 1 shows a state in which the piston 10c of the hydraulic cylinder device 10 is located at the right stroke end and the ram 8 is located at the rising end.

In FIG. 1, when the hydraulic pressure applied to the right pressure receiving surface of the piston 10c of the hydraulic cylinder device 10 is made greater than that to the left pressure receiving surface, the rod 10b protrudes.

When the rod 10b of the hydraulic cylinder device 10 protrudes, as shown in FIG.
A pressing force Q is applied to one lever link 12, and its reaction force is applied to the other lever link 12, and this pressing force Q and its reaction force act on the lever link 12 as a rotational moment M.

This rotation moment M is calculated by the bed 2 and the ram 8.
A pair of pull links 20 arranged on both sides of the
The pair of pull links 20 rotate synchronously by the same angle in opposite directions (both inward with respect to the bed 2) about the pull link support shaft 4, thereby applying a pressurizing force P to the ram 8. Press down to reach the lower end as shown in FIG. At the lower end of the ram 8, the pull link support shaft 4, lever link support shaft 16, and pivot shaft 22 are located on the same straight line in this order.

The mechanism of the connecting part between the lever link 12 and the pull link 20, in which the pressing force Q of the hydraulic cylinder device 10 is converted into the pressing force P of the ram 8, is a kind of toggle mechanism, so that the pressing force P is converted into the pressing force P. It becomes significantly larger than Q. Therefore, the capacity of the hydraulic cylinder device 10 used may be small.

In the state shown in FIG. 2, if the hydraulic pressure applied to the left pressure receiving surface of the piston 10c of the hydraulic cylinder device 10 is made larger than that of the right pressure receiving surface,
The rod 10b retracts and the ram 8 rises.

In this way, when the magnitude of the hydraulic pressure applied to the left and right pressure receiving surfaces of the piston 10c of the hydraulic cylinder device 10 is changed and the rod 10b is moved in and out at a constant stroke, the rod 10b is placed on both sides of the bed 2 and the ram 8. A pair of pull links 20 operating in synchronization with each other move the ram 8 up and down via the pair of pull links 20 operating in synchronization, and press processing is performed using a die consisting of an upper die 24 and a lower die 26. are performed continuously.

A second embodiment of the present invention is shown in FIGS. 5 and 6, and the same parts as in the first embodiment are given the same reference numerals.

The press device of the second embodiment has a cylinder body 1 of a hydraulic cylinder device 10 at the lower end of the ram 8.
The pivot shaft 18 that pivotally connects each lever link 12 to the lever links 12 and 0a and rod 10b is located between the lever link support shaft 16 and the pivot shaft 22 that pivotally connects the lever link 12 and the pull link 20. Since the press device is located at No explanation will be given.

Since the press device according to the present invention operates the pair of pull links 20 disposed on both sides of the bed 2 and the ram 8 using one hydraulic cylinder device 10, the operations of the pair of pull links 20 are synchronized. . Therefore, the ram 8 moves up and down while maintaining its parallelism to the bed 2 with high precision, thereby increasing the precision of press working.

A pair of pull links 2 for raising and lowering the ram 8
0 are placed on both sides of the bed 2 and the ram 8, allowing a large distance between the load points (corresponding to the distance between the pair of lever link support shafts 16 attached to both sides of the ram 8). Therefore, the structure is strong against unbalanced loads. Further, as shown in FIG. 4, when the pull link 20 rotates, a horizontal component force Px of the pressing force P is applied to each lever link support shaft 16 portion (load point) of the ram 8.
are canceled out and only the vertical component force Py effective for pressurization remains, so horizontal forces unrelated to pressurization are not applied to the guide portion of the guide tube 6 and guide rod 14, and the dynamic force of the ram 8 is reduced. Accuracy is improved.

Since there is no part corresponding to the crown of the conventional rigid frame, the overall height of the press is reduced, making it possible to install it in a low factory building and reducing the total weight of the press.

Furthermore, since the bed 2 and the ram 8 can be assembled by hinge-coupling and connecting them with a pair of pull links 20, the horizontality and verticality of each member can be maintained with high precision, and each member can be strongly strengthened. Compared to conventional frames that are rigidly connected to the frame, it is extremely easy to assemble, and at the same time, it is also easy to achieve precision during assembly.

In the above embodiment, a hydraulic cylinder device is used as the drive cylinder device for synchronously operating the pair of pull links, but an electric cylinder device may also be used.

〔Effect of the invention〕

(1) The bed and ram are connected by a pair of pull links, and a single drive cylinder device operates the pair of pull links synchronously to raise and lower the ram, which is different from conventional press equipment. This eliminates the need for a press frame with a rigid structure, which was considered indispensable, and makes it possible to inexpensively manufacture a press device that has a low overall height, high processing accuracy including dynamic accuracy, and is resistant to eccentric loads.

(2) Since the horizontal components of the respective pressurizing forces applied to the left and right lever link support shafts provided on the ram cancel each other out, the mechanism is complicated and expensive, unlike conventional crank presses. There is no need to provide a ear guide to remove the horizontal component of the pressing force, and a press device with a simple mechanism and high dynamic accuracy can be realized.

(3) A hydraulic press that uses multiple hydraulic cylinders to raise and lower the ram requires a synchronization mechanism for each hydraulic cylinder, making the mechanism complex and expensive. The press device according to the present invention is configured to raise and lower the ram by synchronously operating a pair of pull links using a single drive cylinder device, so a synchronization mechanism is not required.

(4) The mechanism of the connecting part between the lever link and the pull link, where the pressing force of the cylinder device is converted into the pressing force of the ram, is a kind of toggle mechanism.
Since the pressing force of the ram is significantly larger than the pressing force of the drive cylinder device, the capacity of one drive cylinder device used may be small, and the energy saving effect is also large.

[Brief explanation of drawings]

1 to 4 are diagrams for explaining a press apparatus according to a first embodiment of the present invention, and FIGS. 1 and 2 show the ram 8 located at the rising end and the descending end, respectively. The front sectional view in the state shown in Figure 3 is
FIG. 4 is a side sectional view showing the ram 8 at the lower end, and is a schematic front view for explaining the deformation of the bed 2 and the ram 8, as well as the pressing force of the ram 8. FIG. 5 and FIG. 6 are diagrams for explaining a press device according to a second embodiment of the present invention, and are front sectional views in a state where the ram 8 is located at the ascending end and the descending end, respectively. . 7 to 10 are diagrams for explaining a conventional press device, and FIG. 7 is a side view of a C-shaped press frame;
Figure 8 is a front view of the gate-shaped press frame;
The figure is a front view of a press apparatus using a plurality of hydraulic cylinders 60, and FIG. 10 is a view of a plunger guide 68 of the crank press. The explanations of the symbols of the main parts constituting the present invention are as follows. C...Bed center line, 2...Bed, 4...Pull link support shaft, 6...Guide cylinder part (guide part),
8... Ram, 10... Hydraulic cylinder device (drive cylinder device), 10a... Cylinder body, 10b
... Rod, 12 ... Lever link, 14 ... Guide rod (guide portion), 16 ... Lever link support shaft, 20 ... Pull link.

Claims (1)

[Scope of Claims] 1. A bed, a ram disposed above the bed so as to be movable up and down via a guide part, and pull link support shafts located at symmetrical positions with respect to the bed center line on both sides of the bed. a pair of pull links whose lower ends are pivotally connected through the lever link support shafts, and lever link support shafts located directly above the pull link support shafts on both sides of the ram and symmetrically with respect to the bed center line; a pair of lever links pivotally connected to each other, and a drive cylinder device disposed approximately horizontally between the pair of lever links, the connection between the pull link and the lever link at the lowering end of the ram. The two links are pivotally connected to each other via a pivot shaft such that the lever link support shaft is directly above the lever link support shaft and is located symmetrically with respect to the bed center line. By moving the rod in and out, each lever link can rotate about the lever link support shaft, so that the cylinder body of the drive cylinder device and the rod can be pivoted to each lever link disposed on the side thereof. 1. A press device, characterized in that the pair of pull links and the pair of lever links are operated synchronously by moving a rod of a drive cylinder device in and out to move the ram up and down.