JPH08197299A - Spheric face point device of hydraulic press - Google Patents

Abstract

PURPOSE: To provide a spheric face point device which absorbs the eccentric load generating caused by the deformation of a press body and which can make low the total height of the press body. CONSTITUTION: In a hydraulic press which drives a slide 4 up and down with a hydraulic cylinder 2, on a point 3 to connect the top end of piston pestle 2a of the hydraulic cylinder 2 and the slide 4, a nut member 3a having a projecting spheric face 3b and a ram 3c having a recessing spheric face 3d abutting with sliding to the projecting spheric face 3b of the nut member 3a are installed. These nut members 3a and ram 3c are received inside covers 3e, 3f filled with the oil. Because the eccentric load is absorbed by mutually abutting with sliding the projecting spheric face 3b and the recessing spheric face 3d, the bending stress is not generated at each part of the hydraulic cylinder, further because the height of the point 3 can be made lower than the spheric face bearing of using a spheric body, the total height of the press body can be made low.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a spherical point device for a hydraulic press.

[0002]

2. Description of the Related Art Conventional press machines include a mechanical press that converts a rotary motion into a reciprocating motion by a crank mechanism and transmits it to a slide, and a hydraulic press that directly reciprocates a slide by a hydraulic cylinder. In a mechanical press, the connecting rod that converts the rotation of the crankshaft into reciprocating motion swings,
Between the connecting rod and the slide, for example
As shown in Japanese Patent No. 9500 and Japanese Utility Model Laid-Open No. 1-105097, spherical points are provided.

Further, in the case of a hydraulic press, since there is no swinging member such as a connecting rod, a spherical point is not used and, for example, as shown in FIG.
A flange c is provided at the tip of the piston rod b, and the flange c is surrounded by a cover d that is divided into two parts, and the cover d is fixedly fixed to the slide e.
And slide e are connected.

[0004]

However, in a mechanical press using a spherical body as the spherical point, it takes a lot of time and labor to accurately process the spherical body and the spherical receiving body that receives the spherical body. Since the height of the press is also high, there is a problem that the total height of the press becomes high and the press becomes large.

Further, in the case where the flange c provided at the tip of the piston rod b is surrounded by the cover d and fixed to the slide e,
When the press body is formed of the C frame f as shown in FIG. 1B, the C frame f is opened by the forming load as shown by the phantom line in FIG. Result Hydraulic cylinder a mounted on top of C frame f
Is inclined as shown in (c) of FIG. 1, and as a result, bending stress is generated in the portions indicated by A and B of the hydraulic cylinder a and these portions are prematurely damaged, or the seal material is prematurely worn. There is a problem such as causing oil leakage. The present invention has been made to solve such a problem, and an object of the present invention is to provide a spherical point device for a hydraulic press capable of absorbing an eccentric load generated by deformation of the press body and reducing the overall height of the press body. To do.

[0006]

In order to achieve the above object, the present invention provides a hydraulic press in which a slide is driven up and down by a hydraulic cylinder, in which a convex spherical surface is provided at a point where the tip of the piston rod of the hydraulic cylinder is connected to the slide. A nut member and a ram having a concave spherical surface that slidably contacts the convex spherical surface of the nut member are provided, and the nut member and the ram are housed in an oil-filled cover.
Further, a gap is provided between the nut member and the inner surface of the cover to allow vertical and horizontal movement of the nut member, and a gap is provided between the ram and the inner surface of the ram to allow horizontal movement of the ram. .

[0007]

[Operation] With the above structure, the processing area of the spherical surface can be greatly reduced and the height of the point portion can be reduced as compared with the case where the spherical bearing made of a sphere is provided at the point. Further, even if the C frame is deformed by the press load, the nut member and the convex spherical surface and concave spherical surface of the ram are in sliding contact with each other to absorb them, so that excessive bending stress may be generated in each part of the hydraulic cylinder. Absent. Further, when punching a workpiece, even if the slide moves in three dimensions, the gaps provided between the nut member and cover and between the ram and cover absorb this, so excessive bending stress may be applied to the piston rod. Absent.

[0008]

Embodiment An embodiment of the present invention will be described in detail with reference to the drawings shown in FIGS. 2 is a side view of the hydraulic press, and FIG. 3 is an enlarged sectional view of the spherical point device. Figure 2
In FIG. 1, reference numeral 1 denotes a press body, which has a C frame 1a, and a hydraulic cylinder 2 is attached to the upper portion of the C frame 1a substantially vertically. A piston rod 2a projects downward from the hydraulic cylinder 2, and a slide 4 is attached to the tip of the piston rod 2a via a point 3. The slide 4 has vertical movement guided by a slide guide (not shown), and is mounted on an upper die (not shown) attached to the lower surface of the slide 4 and a bolster 5 fixed on the bed 1b of the C frame 1a. Press molding is performed between the placed lower molds (not shown).

Further, the above point 3 is as shown in FIG.
It has a nut member 3a screwed to the tip of the piston rod 2a. The bottom surface of the nut member 3a is a dish-shaped convex spherical surface 3b whose height is lower than that of the hemispherical surface, and the convex spherical surface 3b receives a press load.
The concave spherical surface 3 formed on the upper surface of the ram 3c is formed on the convex spherical surface 3b.
d is closely contacted so that it can be moved. The convex spherical surface 3b and the ram 3c of the nut member 3a are housed in a vertically divided cylindrical upper cover 3e and lower cover 3f. A circular hole 3g slightly larger than the outer diameter of the upper portion of the nut member 3a is opened in the upper cover 3e, and the upper portion of the nut member 3a is projected from the circular hole 3g. The diameter is larger, and gaps 3h and 3i are provided between the upper surface and outer peripheral surface of the large-diameter lower portion and the inner upper surface and inner peripheral surface of the lower cover 3f.

On the other hand, the outer diameter of the ram 3c is the same as the nut member 3a.
Is formed to be slightly smaller than the outer diameter of the lower part of the lower cover, the bottom surface slidably contacts the inner bottom surface of the lower cover 3f, and a gap 3k is provided between the outer peripheral surface and the inner peripheral surface of the lower cover 3f. At the same time, a key 3j is provided on the bottom surface of the lower cover 3f, and the lower cover 3 is attached to the slide 4 while the key 3j is fitted in the key groove 4a provided on the slide 4 side.
f is fixed.

Next, the operation will be described. Hydraulic pressure is supplied to the upper chamber of the hydraulic cylinder 2 to lower the slide 4, and between the upper die mounted on the lower surface of the slide 4 and the lower die mounted on the bolster 5. Press molding is performed, but the press load is the nut member 3
It is supported by the convex spherical surface 3b of a. Further, even if the C frame 1a is deformed by the press load and the hydraulic cylinder 2 provided on the upper part of the C frame 1a is tilted by this, the convex spherical surface 3b of the nut member 3a and the concave spherical surface 3d of the ram 3c slide. Since this is absorbed, an excessive bending stress is not applied to the hydraulic cylinder 2 side, and even if the slide 4 side is inclined due to an eccentric load during press molding, the convex spherical surface 3b of the nut member 3a and the concave spherical surface 3d of the ram 3c are prevented. Slides and absorbs this, so that an unbalanced load does not act on the hydraulic cylinder 2 side. Further, the convex spherical surface 3b of the nut member 3a and the ram 3c
The concave spherical surface 3d is slidable in the three-dimensional direction, and is between the nut member 3a and the upper cover 3e, and between the ram 3c and the lower cover 3.
Since the gaps 3h, 3i, 3k are provided between f, the slide 4 can be used, for example, when performing punching work with a press.
Is inclined in the three-dimensional direction, the sliding surfaces and the gaps 3h, 3i,
Since 3k absorbs this, excessive bending stress is not applied to the piston rod 2a side of the hydraulic cylinder 2.

In the above embodiment, the nut member 3a side is the convex spherical surface 3b and the ram 3c side is the concave spherical surface 3d. However, as shown in FIG. 4, the nut member 3a side is the concave spherical surface 3d.
And the convex spherical surface 3b may be formed on the ram 3c side.

[0013]

As described above in detail, according to the present invention, the spherical point connecting between the piston rod and the slide of the hydraulic cylinder is formed by the nut member and the ram having the convex spherical surface and the concave spherical surface which are in sliding contact with each other. Therefore, since the processing area of the spherical surface is significantly smaller than that of the conventional spherical surface using a spherical body, the processing cost of the spherical surface having precision processing can be significantly reduced. Also, since the height of the point portion can be made smaller, the overall height of the press becomes lower, which allows the press to be made smaller and have higher rigidity, and even if the C frame is deformed by the press load, the convex spherical surface of the nut member and the ram can be improved. Since the concave spherical surface and the concave spherical surface are in sliding contact with each other and absorb this, excessive bending stress does not occur in each part of the hydraulic cylinder, which damages the hydraulic cylinder and seals, and wears the sliding part early. It is possible to solve such problems. Furthermore, when punching the work,
Even if the slide moves in three dimensions, the sliding surfaces between the nut member and the ram, the gaps between the nut member and the cover, and between the ram and the cover absorb this, so that excessive bending stress is applied to the piston rod. Nor.

[Brief description of drawings]

1A to 1C are explanatory views showing a conventional hydraulic press.

FIG. 2 is a side view of a hydraulic press according to an embodiment of the present invention.

FIG. 3 is a sectional view showing a spherical point device of a hydraulic press according to an embodiment of the present invention.

FIG. 4 is an explanatory view showing a spherical point device for a hydraulic press according to another embodiment of the present invention.

[Explanation of symbols]

 1 ... Press body 2 ... Hydraulic cylinder 2a ... Piston rod 3 ... Point 3a ... Nut member 3b ... Convex spherical surface 3c ... Ram 3d ... Concave spherical surface 3e ... Upper cover 3f ... Lower cover 3h, 3i, 3k ... Gap 4 ... Slide.

Claims (2)

[Claims] 1. In a hydraulic press in which a slide 4 is vertically moved by a hydraulic cylinder 2, a point 3 connecting a tip of a piston rod 2a of the hydraulic cylinder 2 and the slide 4 to each other.
Is provided with a nut member 3a having a convex spherical surface 3b and a ram 3c having a concave spherical surface 3d slidably contacting the convex spherical surface 3b of the nut member 3a.
A spherical point device for a hydraulic press, wherein c is accommodated in covers 3e and 3f filled with oil. 2. A gap 3h, 3i is provided between the nut member 3a and the inner surfaces of the covers 3e, 3f to allow the nut member 3a to move in the vertical and horizontal directions, and between the ram 3c and the inner surface of the cover 3f. 3 that allows the horizontal movement of the
The spherical point device for a hydraulic press according to claim 1, wherein k is provided.