JP3213874B2 - Mechanical press - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mechanical press in which a mold closing time of a mechanical press can be adjusted, thereby preventing a spring bag of a molded product and improving processing accuracy. .

[0002]

2. Description of the Related Art A hydraulic press machine can be stopped while a press die reaches a bottom dead center while maintaining a pressurized state on a product, so that it is easy to prevent a spring bag. . However, in a mechanical press, the press die continuously moves up and down from the bottom dead center to the top dead center, so it is impossible to stop the press die and the occurrence of a spring bag is unavoidable. And has been.

Therefore, in a press operation using a conventional mechanical press machine, a product having a prescribed shape is obtained by previously correcting the bending radius and angle of a mold tool by an amount corresponding to a spring bag. is there.

[0004] However, since the spring bag differs depending on the material, thickness, shape, etc. of the product, in order to obtain a high-precision product in response to the problem, a high level of skill is required of an engineer. there were.

In a mechanical press, a die height (die height) is generated by thermal expansion or deformation of a frame.
Changes in product processing accuracy,
Since the press die may be damaged, there is a problem in that the press machine must be frequently stopped during the processing to adjust the die height.

[0006]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and maintains a mold-closed state of a mechanical press machine and adjusts the mold-closing time. An object of the present invention is to provide a mechanical press in which a processing accuracy of a pressed product is improved by preventing a spring bag generated in the product and eliminating a variation in the processing accuracy due to a change in die height.

[0007]

In order to achieve the above object, a mechanical press according to the present invention comprises a crankshaft.
Connect the connection rod to change the rotary motion into linear motion.
The ram connected via the traction screw moves up and down
Mechanical press to obtain a predetermined press pressure
In the ram of the screw machine, the lower end of the connection screw
Drilling machine that supports the ball section of
A mechanical press comprising a pressurizing chamber, wherein the ram
The pressure adjusting chamber of the pressure adjusting device is connected to the internal pressure chamber via a connecting pipe.
Stroke until the ram reaches the bottom dead center
The press mold is adjusted so that the mold is closed
On the other hand, the pressure is increased by a piston provided in the pressure adjusting chamber.
The fluid sealed in the adjusting chamber, the connecting pipe, and the pressurizing chamber is
Pressing into the pressurizing chamber is smaller than the press pressure of the press machine
By applying a load to the ram,
Of the press for the lowered and raised strokes
A load smaller than the press pressure acts on the press die.
This is a feature of the present invention .

[0008]

In the above construction, the closing of the press die is completed with the stroke remaining until the ram reaches the bottom dead center, and the remaining descending and rising strokes are reduced by the pressing pressure of the press machine. Since the smaller load acts on the press die, the load keeps the press die pressed for the product by maintaining the mold closed state for the remaining descending and rising strokes, thereby increasing the pressurizing energy for the product. Accumulation makes it possible to mold high-precision products without spring bags.

[0009]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a partial sectional side view of a mechanical press and a pressure adjusting device according to the present invention. FIG. 2 is a partially enlarged view showing the ram side of FIG. FIG. 3 is a longitudinal sectional view of the pressure adjusting device of FIG. FIG. 4 is an explanatory view showing the operation of the mechanical press shown in FIG.

In FIG. 1, a connection rod 3 for changing a ram 4 into a linear motion is connected to a crankshaft 2 rotated by a motor (not shown) built in an upper portion of a frame 13. The connection rod 3 has a male screw 1 provided on the outer periphery of a connection screw 12.
2b is screwed, and the height can be adjusted by rotating the connection screw 12.

Further, a ball portion 12a provided at a lower end of the connection screw 12 is rotatably supported by a drilling machine 7, and the drilling machine 7 is provided with a pressurizing chamber 8 provided in a ram 4.
Are slidably fitted to.

The pressurizing chamber 8 is provided as a hydraulic chamber constituting an overload safety device in the conventional device, and when the hydraulic pressure in the hydraulic chamber rises above a specified value, the safety device operates. The press machine 1 stops.

With such a configuration, the ram 4 is provided so as to be vertically movable along a guide (not shown), and can be moved up and down by driving the connection rod 3.

A two-dot chain line on the lower surface of the ram 4 in FIG.
Is shown. Below the ram 4, a support plate 13 of the frame 13 is provided.
The bolster 5 is fixed via a. Upper and lower press dies 6 are provided between the die 14 and the bolster 5, and a product before pressing is placed in the press dies 6.

In such a mechanical press, a connecting pipe 16 is connected to the pressurizing chamber 8 by a coupler 15.
The connection pipe 16 is connected to a pressure adjustment chamber 11 of the pressure adjustment device 10 described later, and the pressure chamber 8 including the connection pipe 16 and the pressure adjustment chamber 11 are filled with a fluid such as oil. .

The pressure adjusting device 10, as shown in FIG.
Inside the rectangular frame 18 fixed to the fixed plate 17, a cylinder 20 is mounted on one side of the support plate 19a by bolts 21.
The pressure adjustment chamber 11 is provided in the cylinder 20, and the piston 9 is slidably fitted in the pressure adjustment chamber 11. The coupler 15 fixed to the other end of the connecting pipe 16 is connected to the through hole 22 provided at the center of the support board 19a, so that the pressurizing adjustment chamber 11 and the pressurizing chamber 8 of the press 1 are connected. And are in communication.

A large diameter adjusting screw 24 fixed to the rear end of the gas pressure cylinder 23 is screwed to another supporting board 19b of the pressure adjusting device 10, and an adjusting screw provided at the rear end of the adjusting screw 24 is provided. By rotating the handle 25, the gas pressure
The da 23 can be moved back and forth.

The gas pressure cylinder 23 has a piston rod 9a.
And the position of the piston 9 can be adjusted by moving the gas pressure cylinder 23 back and forth. The gas pressure cylinder 23 can be replaced by, for example, a hydraulic cylinder or an elastic member using a spring or a disc spring.

In FIG. 1, a press 1 according to the present embodiment comprises:
As described above, the pressure adjusting device 10 is provided with the pressurizing chamber 8 communicated with the pressure adjusting chamber 11 of the pressure adjusting device 10.
When the drilling machine 7 supporting the lowering of the pressurizing chamber 8 raises the hydraulic pressure in the pressurizing chamber 8, the pressurizing adjusting device 10
The piston 9 is pressed backward from the rear by the gas pressure cylinder 23 at a predetermined pressure, so that the piston 9 resists compression of the pressurizing chamber 8 on the press 1 side,
It exerts a load when the drilling machine 7 descends.

In order for the press machine 1 to function properly, the remaining stroke of the ram 4 is required when the ram 4 descends and the press die 6 is completely closed.

FIG. 4 (Crankshaft 2)
The height of the ram 4 is adjusted so that the press die 6 is closed before the crankshaft 2 descends from the top dead center 30 to reach the bottom dead center 31. If so, the press die 6 can be kept stopped from the time 32 when the press die 6 is closed to the time 33 when the press die 6 is released.

That is, in FIG. 4, the remaining descending stroke of the ram 4 is changed from the mold closing 32 of the press mold 6 to the bottom dead center 31.
Until then, the remaining ascent stroke of ram 4 is at bottom dead center 31
To the release 33 of the press die 6,
During the descending stroke and the ascent stroke, the stopped state in which the press die 6 is closed can be maintained.

The stop time of the press die 6 is
Is determined by how much remaining stroke the ram 4 takes from the mold closing to the bottom dead center. This must be determined for each product because the time for the spring bag to disappear depends on the material and shape of the product, but if the remaining stroke is set with a margin, the stroke of the ram 4 must be determined roughly. Can be.

To adjust the stroke of the ram 4,
As described above, the rotation can be performed by rotating the connection screw 12 with respect to the connection rod 3.

Further, in order for the above-mentioned press machine 1 to function properly, means for absorbing the above-mentioned remaining stroke and maintaining a predetermined press pressure on the press die 6 is necessary.

For this reason, in the present embodiment, the gas pressure cylinder 23 on the pressure adjusting device 10 side is designed to exert a load smaller than the original press pressure of the press machine 1 in the pressure chamber 8 in the ram 4. The position is moved by the adjustment handle to adjust the internal volume of the pressure adjustment chamber 11 to apply a predetermined load to the pressure chamber 8 in the ram 4.

With this configuration, a predetermined load is applied by the pressure adjusting device 10 while the press die 6 is kept closed while the press die 6 is released. Accumulates pressurizing energy for
It is possible to mold a product having a predetermined shape without a spring bag.

As described above, the press 1 of this embodiment requires the separate pressure adjusting device 10, but the conventional hydraulic chamber is used as the pressure chamber 8, 1
5, the conventional press 1 can be used as it is.

It should be noted that the pressure adjusting chamber 11 of the pressure adjusting device 10 of this embodiment is filled with a block, etc.
Can be used as a normal press machine 1 if is fixed. At this time, it is necessary to adjust the stroke to a normal stroke by rotating the connection screw 12.

[0031]

As described above, according to the mechanical press of the present invention, the hydraulic chamber of the conventional press is used as the pressurizing chamber.
During the lowering and raising strokes left on the ram, a load smaller than the pressing pressure of the pressing machine acts on the pressing die, thereby maintaining the closed state of the pressing die. By accumulating the pressurizing energy for the product, it is possible to obtain a product having a prescribed shape with high processing accuracy without a spring bag.

If the remaining strokes are set with a margin, the stroke of the ram can be determined roughly, and there is no need to perform strict die height adjustment as in the prior art, and it is easy even without advanced skills. High-precision press working can be performed.

[Brief description of the drawings]

FIG. 1 is a partial sectional side view of a mechanical press and a pressure adjusting device according to the present invention .

FIG. 2 is a partially enlarged view showing a ram side of FIG. 1;

FIG. 3 is a longitudinal sectional view of the pressure adjusting device of FIG. 1;

FIG. 4 is an explanatory view showing the operation of the press machine of FIG. 1;

[Description of sign]

 DESCRIPTION OF SYMBOLS 1 ... Press machine 2 ... Crankshaft 3 ... Connection rod 4 ... Ram 5 ... Bolster 6 ... Press type 7 ... Drilling machine 8 ... Pressurizing chamber 9 ... Piston 10 ... Pressurizing adjusting device 11 ... Pressurizing adjusting chamber 12 ... Connection screw 12a ... Connection screw ball 13 ... Frame

Claims (1)

(57) [Claims] 1. The rotation of a crankshaft is converted to a linear motion.
Change connection rod through connection screw
When the connected ram moves up and down,
In the ram of the mechanical press machine to obtain the pressure
Supports the ball at the lower end of the connection screw
Machine comprising a pressurizing chamber in which a drilling machine is slidably provided
In a mechanical press machine, pressurize and adjust the pressurizing chamber in the ram
The pressure adjusting chamber of the device is communicated via a connecting pipe, and the ram
Press mold is left, leaving the stroke until it reaches the bottom dead center.
While being adjusted to be closed, it is installed in the pressure adjustment chamber.
The pressurized adjusting chamber, the connecting pipe, and the
The fluid sealed in the pressurizing chamber is pressed and the fluid is
When a load smaller than the press pressure of the press machine is applied
The lower and upper strikes left on the ram.
Negative pressure less than the press pressure of the press against the roak
A mechanical press machine wherein a load acts on the press die .