JPH0133224Y2 - - Google Patents

Description

[Detailed description of the invention] (Field of industrial application) This invention is a pressing mechanism that is used in a press forming machine, for example, as a wrinkle holding mechanism to pinch the flange of a workpiece when drawing the workpiece. Regarding equipment.

(Prior Art) Conventional press forming machines employ a spring-directly connected wrinkle-holding mechanism in which a spring directly presses a wrinkle-holding ring to pinch the flange of the workpiece.

(Problems to be Solved by the Invention) In the case of the wrinkle holding mechanism described above, as shown in FIG. There was a problem in that the restraining force applied to the flange to prevent wrinkles from changing in a parabolic manner fluctuated during the molding process, making it impossible to fully exert the wrinkle suppressing effect.

An object of the present invention is to provide a pressing device for a press molding machine that can even out and stabilize the pressing force.

(Means for Solving the Problems) The present invention consists of a pressure plate fitted to be vertically slidable near the upper end of a stud fixed in an upright position, and a yoke fitted to the lower end of the stud. the upper link piece and the lower link piece are connected via at least two links that are articulated so as to be able to bend and extend, and the free end of the cushion body is loosely fitted to the stud to restrict upward movement. A movable plate slidably fitted to the stud is disposed opposite to the stud, and the cushion body is compressed and deformed via the movable plate at the lower end of the link when the link is bent. The gist of the present invention is to provide a pressing device in which protruding push-up portions are respectively formed to urge the links in the direction of extension using compressive elastic force.

(Function) The device of the present invention connects a pressure plate loosely fitted near the upper end of the stud and a yoke fixed to the lower end of the stud with a link formed to be able to bend and extend, and also connects the cushion body to the center of the stud. When the pressure plate is pushed down and the link is bent, the cushion body is compressed and deformed by the rocking motion of the push-up part formed at the lower end of the link, and the link is It is configured so that it is biased in the direction of extension and the pressing force is transmitted to the pressure plate.

(Example) Next, an example in which the pressing device of the present invention is applied to a wrinkle pressing mechanism will be described with reference to the drawings.

First, let's talk about the forming mechanism of the press forming machine in Part 4.
To explain according to the figure, a pressure die 1 is installed to be able to move up and down above a workpiece W, and is supported by a holder 2 connected to a drive mechanism (not shown) via a stripper bolt 3, and supported by springs 4 to 4.
A die ring 5 for suppressing wrinkles is fitted onto the presser die 1.

A punch 6 installed on the die holder 7 in order to press-form the workpiece W which is intermittently transferred laterally in cooperation with the pressure die 1 is placed concentrically opposite the bottom of the pressure die 1, and has an upper end. A ring-shaped floating punch 8 is slidably fitted onto the outside of the floating punch 8, and the flange W1 of the workpiece W is completely cut between the floating punch 8 and the die ring 5 during the forming process of the workpiece W. A wrinkle presser ring 9 is slidably fitted on the outside of the die ring 5 in order to clamp the die ring 5 around the circumference, and the wrinkle presser ring 9 is slidable below the base of the punch 6 and the die holder 7. A suitable number of pressure pins 10 are inserted vertically and are opposed to each other so as to be able to press down, and a ring-shaped punching die 11 fixed to the punch 6 is fitted onto the wrinkle press ring 9.

Next, to explain the pressing device P, near the upper end of the stud 12 which is fastened to the lower surface of the die holder 7 and hangs concentrically below the punch 6, there is a disc-shaped boss with a boss in order to push up the pressure pin 10. Formed pressure plate 13
is fitted so as to be slidable up and down, and is in contact with the die holder 7 in the released state. And stud 1
The threaded portion 12a formed near the center of the cushion body 14 is fixed by restricting the upward movement of the cushion body 14 (in this example, a disc spring is used) loosely fitted near the center of the cushion body 12a. A positioning member 15 for positioning the end is screwed so as to be adjustable in vertical movement, and is pressed against the free end of the cushion body 14 below the threaded portion 12a, so that the cushion body 14 is held between the positioning member 15 and the positioning member 15. A movable plate 16 formed for this purpose is fitted so as to be slidable in the axial direction, and on the lower surface of this movable plate 16, a cam surface 16a that is slightly inclined upwardly toward the outside is provided over the entire circumference. It is formed. In addition, stud 1
A yoke 17 having a pair of extending portions 17a, 17a extending laterally symmetrically is fitted into the lower end of the yoke 2 and fastened with a nut 23.

A pair of left and right links 18, 18 arranged in parallel to connect the pressure plate 13 and the yoke 17 in an expandable/contractable manner is an upper link whose upper end is pivotably pinned 19 to the pressure plate 13. Piece 18
a and a lower link piece 18b, the lower end of which is attached to the extension part 17a of the yoke 17 with a pin 20 so as to be swingable, are connected to each other so that the link 18 can bend and extend. In order to push up the movable plate 16 and compressively deform the cushion body 14, push-up parts 21 are formed that are opposed to the movable plate 16 and project inward in an upwardly inclined manner. Push-up rollers 22, 22 are each pivotally supported so as to be able to roll in pressure contact with the cam surface 16a of the movable plate 16.

Next, the operation and effects of the embodiment having the above configuration will be explained.

Now, when forming the workpiece W, the presser die 1 descends from the top dead center of the stroke, comes into contact with the workpiece W on the way down, and presses the center part of the workpiece W between the punch 6 and the presser die 1. The punch 6 is pressed down to press-form the center part of the workpiece W, and the lowered die ring 5 holds the wrinkle presser ring 9 with the flange W1 of the workpiece W sandwiched between it and the wrinkle presser ring 9. For pressing down, a pressing device P
The pressing force of the die ring 5 is transmitted to the pressure plate 13 via the pressure pin 10, and the pressure plate 13 is pressed down (see FIG. 4B). Then, as the pressure plate 13 moves downward, both links 18 in the extended state bend in opposite directions, and both push-up parts 21 swing in opposite directions using the pin 20 as a fulcrum, and the push-up roller 22 moves the movable plate 16 The movable plate 16 is pushed up by sliding on the cam surface 16a, and the cushion body 14 is compressed and deformed, so that the compression elastic force of the cushion body 14 causes both links 18 to be urged in the extension direction by this elastic force. is transmitted to the pressure plate 13 via the pressure plate 13, the pressure pin 10 is urged upward via the pressure plate 13, and the flange W1 of the workpiece W is moved to the workpiece W after the downward stroke of the pressure die 1 is completed. The punch 6 is held in a state of being elastically sandwiched between the die ring 5 and the wrinkle holding ring 9 until the forming of the central part of the flange W1 is completed, and the punch 6 moves slightly upward together with the die holder 7, and the flange W1 and the die holder 5 are held together with the wrinkle holding ring 9. It is drawn and formed while being elastically held between the presser link 9 (see FIG. 4C).

Then, when the pressure die 1 and die ring 5 move upward and the punch 6 and wrinkle presser ring 9 are released, the cushion body 14 is restored and both links 18 are extended, and the pressure plate 13 moves upward. While in contact with the die holder 7, it waits for forming the next workpiece W.

Therefore, during the molding process, the pressure plate 13
Even if the cushion body 14 is pressed down by the pressure pin 10, the cushion body 14 is compressively deformed while the movable plate 16 is held in a substantially fixed position during the molding process, and the amount of compressive deformation of the cushion body 14 is limited. 13, the pressing force f of the pressure plate 13 with respect to the compressive deformation l of the cushion body 14 becomes almost constant, as shown by a in FIG. 5, and the pressing characteristics of the pressing device P are has been improved, the elastic force applied to the pressure pin 10 via the pressure plate 13 is almost constant, and the restraint force on the flange W1 of the workpiece W is balanced and stable from the start of forming to the end of forming. It is possible to hold and form the workpiece W, which has the effect of eliminating problems such as forming defects such as wrinkles and unequal thickness due to excessive or insufficient clamping force on the flange or fluctuations over time. .

In addition, since the movable plate 16 is formed with a cam surface 16a that tilts upward toward the outside, the cushion body 1 responds to the amount of displacement of the pressure plate 13.
It is possible to further reduce the amount of compressive deformation of 4 and improve the pressing characteristics for pressing the pressure plate 13.

Incidentally, as the cushion body 14, a coil spring, a rubber cylinder, or the like may be used instead of the disc spring of the above embodiment.

(Effects of the invention) That is, the present invention includes a pressure plate fitted in the vicinity of the upper end of a stud fixed in an upright state so as to be slidable up and down, and a yoke fitted to the lower end of the stud. The upper link piece and the lower link piece are connected via at least two links that are articulated so as to be able to bend and extend, and the free end of the cushion body, which is loosely fitted to the stud and whose upward movement is regulated, has the above-mentioned A movable plate slidably fitted to the stud is disposed opposite to the stud, and the lower end of the link is provided with a compressive force that compresses and deforms the cushion body through the movable plate when the link is bent. By forming the protruding parts to urge the links in the direction of extension with force, there is an effect that the pressing force can be balanced and stabilized and the pressing characteristics can be improved.

Note that the pressing device of the present invention can also be applied to a dictation.

[Brief explanation of the drawing]

Drawings Showing one embodiment of the present invention, Fig. 1 is a front view of the pressing device, Fig. 2 is a front view when it is in operation, Fig. 3 is a side view, and Fig. 4 A, B, and C are the same. FIG. 5 is a longitudinal sectional view of the forming mechanism showing the forming process in order, and a characteristic curve diagram showing the relationship between the amount of compressive deformation and the pressing force. 12...Stud, 14...Cushion body, 1
6...Movable plate, 17...Yoke, 18...
Link, 21... Pressing part, P... Pressing device.

Claims (1)

[Scope of utility model registration request] An upper link piece and a lower link piece each connect a pressure plate that is fitted to be vertically slidable near the upper end of the stud that is fixed in an upright state, and a yoke that is fitted to the lower end of the stud. A cushion body is connected via at least two links that are articulated so as to be able to bend and extend, and is loosely fitted to the stud to restrict upward movement; the free end of the cushion body is slidably fitted to the stud. A movable plate is disposed oppositely to the lower end of the link, and the link is attached in a direction in which the cushion body is compressively deformed through the movable plate when the link is bent, and the link is extended by the compressive elastic force of the cushion body. 1. A pressing device for a press molding machine, characterized in that each of the pressing portions is formed with a protruding portion for pressing.