JPS6313875Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a push-out device in a press machine.

This push-out device is installed on the upper die side of the press machine, and is used to forcefully remove workpieces that are stuck to the upper die of the press machine by forcing them downwards immediately after press processing. It is something.

BACKGROUND ART Conventionally, as this type of push-out device, the ones shown in FIGS. 1 and 2 are known.

That is, a cylindrical set bar 2 extending upward is fixed to the upper die 1 of the press device, and a cylindrical first ejector pin 3 that extends downward through the upper die 1 is installed inside the set bar 2. It is fitted in so that it can move up and down while being prevented from coming off. Further, a cylindrical second ejector pin 4 whose lower end is closed is fitted inside the first ejector pin 3 so as to be movable up and down while being prevented from coming off downward. Therefore, set bar 2,
The ejector pin 3 and the second ejector pin 4 are cylindrical bodies having smaller diameters. A plug 5 is attached to the upper end of the set bar 2, and a relatively thin and long spring 6 is interposed in a compressed state between the plug 5 and the lower end closed portion inside the second ejector pin 4. There is. Further, a spring guide 7 extending downward and located inside the spring 6 is provided at the lower central portion of the plug 5 .

Such conventional ejection devices usually have a first
As shown in the figure, the first and second ejector pins 3, 4 are fully extended downward by the restoring force of the spring 6. Then, when the workpiece (worked object) W is moved to the specified press processing position by the fingers 8, the lower end of the second ejector pin 4 first presses against the upper part of the workpiece W as the upper die 1 descends. As a result, the workpiece W is prevented from shifting out of position. Then, as the upper die 1 continues to descend, the first and second ejector pins
The ejector pins 3 and 4 are retracted upward, and the spring 6 is gradually compressed.
Immediately after the pressing process in which the upper die 1 is pressed down to its maximum and the workpiece W is in close contact with the upper die 1, the first and second ejector pins 3, 4 retract into the set bar 2 as shown in Fig. 2, and the spring 6 is compressed to its maximum and its stored force is maximized. After that, when the upper die 1 returns to its upward position, the first and second ejector pins 3, 4 correspondingly expand and contract downward due to the restoring force of the spring 6. As a result, the workpiece W is ejected downward from the upper die 1, and the workpiece W is prevented from becoming stuck to the upper die 1 and becoming unable to separate.
The initial ejection force against the workpiece W is obtained by the maximum stored force of the spring 6.

However, such conventional push-out devices have the following problems.

In other words, since the amount of deflection of the spring 6 is large, its wire diameter cannot be set sufficiently large, and as a result, the initial force applied to the workpiece W by the maximum stored force of the spring is insufficient, and the workpiece W may not be able to fully pop out. Moreover, since a relatively long spring 6 is used, the spring 6 is easily bent, and may even be damaged.

This idea was made in view of the above circumstances,
By using two springs with different strengths connected in series, the above conventional problems are solved,
Another object of the present invention is to provide a push-out device for a press machine that can reliably push out a workpiece completely and also prevent deformation and breakage of the spring.

An embodiment of this invention will be described below with reference to FIGS. 3 to 5. Note that the same parts as in the conventional example are given the same reference numerals, and the explanation thereof will be omitted.

In this embodiment, the spring guide 7 of the plug 5 in the conventional example is eliminated, and instead of one spring 6 in the conventional example, a spring guide 7 is provided between the plug 5 and the lower end closed part inside the second ejector pin 4 A first spring 9, a flange member 10, and a second spring 11 are interposed in series. 1st
The spring 9 has a relatively large diameter corresponding to the inner diameter of the set bar 2 and is strong, while the second spring 9 has a relatively small diameter corresponding to the inner diameter of the second ejector pin 4 and is a weak spring. Moreover, in the lower center part of the flange member 10,
A spring guide 12 is provided that extends downward and is located inside the second spring 11.

Further, on the outer circumferential surface of the flange member 10, three guide grooves 13 are provided at equal intervals along the circumferential direction.
(See Figure 5). Each guide groove 1
3 is a shape along the vertical direction. Further, on the inner circumferential surface of the set bar 2, three grooves corresponding to each guide groove 13 are provided.
Two guide protrusions 14 are provided. Therefore, by fitting these three sets of guide grooves 13 and guide protrusions 14, the flange member 10 is housed inside the set bar 2 in a state where it is prevented from rotating and can freely move up and down.

Further, the outer diameter of the flange member 10 is set to be slightly larger than the inner diameter of the upper end portion 3a of the first ejector pin 3, and the first ejector pin 3 retracts into the set bar 2 as shown in FIG. When this occurs, the upper end portion 3a abuts the flange member 10 and the lower surface position is moved from P ₁ to P ₂ by a slight distance l (2
It is designed to push up by about 3mm).

According to this embodiment constructed in this manner, when the upper die 1 descends after the workpiece W is set, the lower end of the second ejector pin 4 first reaches the upper part of the workpiece W as in the conventional example. The first and second ejector pins 3 and 4 gradually retract upward while being pressed against each other to prevent their displacement. At this time, only the relatively weak second spring 11 is compressed while being guided by the spring guide 12, and the relatively strong first spring 9 is not compressed. In this way, the pressing force for shifting the position of the workpiece W can be relatively weak due to the restoring force of the second spring 11.

Then, the second ejector pin 4 is completely retracted into the first ejector pin 3, and the upper end 3a of the first ejector pin 3 is attached to the flange member 1.
The first spring 9 is forcibly compressed for the first time when it comes into contact with the lower surface of the second spring 9, that is, when the second spring 11 is completely compressed.
Then, while the position of the lower surface of the flange member 10 is displaced from _P1 to _P2 , the first spring 9 is forcibly compressed by about 2 to 3 mm by this displacement amount l. Therefore, immediately after the press process when the upper die 1 descends to the maximum and the workpiece W comes into close contact with the upper die 1, the forceful compression of the relatively strong first spring 9 causes the downward movement of the workpiece W. There will be enough stored power to provide the spring force.

Therefore, when the upper mold 1 returns to the upward position after pressing, a sufficiently large initial force is applied to the workpiece W, especially due to the sufficient stored force of the first spring 9. This initial springing force fully exerts its effect during a relatively short displacement l of about 2 to 3 mm until the lower surface position of the flange member 10 returns from P ₂ to P ₁ , and the workpiece W is Securely push away from the upper mold 1 downward. In this way, the important initial springing force against the workpiece W is obtained relatively strongly mainly by the restoring force of the first spring 9.

Thereafter, as the upper mold 1 rises, the first and second ejector pins 3 and 4 extend downward due to the restoring force of the second spring 11. When the upper die 1 is completely raised again, the first and second ejector pins 3 and 4 return to their fully extended downward position as shown in FIG. 3.

The magnitude of the initial springing force against the workpiece W can be easily varied by adjusting the position of the plug 5 with respect to the set bar 2, adjusting the amount of movement l of the flange member 10, replacing the first spring 9, etc. be able to.

As explained above, according to the push-out device in the press device according to this invention, two springs of different strengths are connected in series, so that the restoring force of one spring, which is particularly strong, is Therefore, the workpiece can be reliably ejected, and the other spring, which is relatively weak, can accurately prevent the workpiece from shifting its position. Moreover, since a guide bar is provided on the flange member, , together with the series configuration of the two springs, it is possible to prevent deformation and damage of these springs.

[Brief explanation of the drawing]

Fig. 1 is a longitudinal cross-sectional view showing a conventional pop-out device in an extended state, Fig. 2 is a longitudinal cross-sectional view showing its retracted state, and Fig. 3 is a longitudinal cross-sectional view showing an embodiment of the invention in an extended state. , FIG. 4 is a longitudinal sectional view showing the retracted state, and FIG. 5 is a plan view of the flange member. 1...Upper mold, 2...Set bar (cylindrical body), 3...
...First ejector pin (tube), 4...Second ejector pin (tube), 5...Plug, 9...
First spring, 10...Flange member, 11
...Second spring, 12...Spring guide, W...Work (workpiece).

Claims (1)

[Scope of utility model registration request] In a push-out device for a press machine, in which a small-diameter cylinder is telescopically fitted in a downwardly biased state into a large-diameter cylinder attached to the upper die of the press machine, and the small-diameter cylindrical body, two springs of different strengths are interposed in series via a flange member, and one spring inside the small-diameter cylindrical body is connected to the flange member. a guide bar positioned such that during the initial retraction stage of the small diameter barrel the weaker of the two springs is compressed and during the final retraction stage of the small diameter barrel the weaker one of the two springs is compressed; A spring-out device for a press machine, characterized in that a relatively strong spring is compressed.