JPH0137792Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to an improvement of a transmission device that converts rotation of the crankshaft of a press into vertical movement of a workpiece push-up pin.

In order to push the molded workpiece out of the mold by the stroke of the slide, the unequal angular velocity rotation of the crankshaft is converted into linear motion by the transmission of the cam, and a push-up pin (hereinafter referred to as a knock-out pin) is used.
Normally, the cam is used to raise and lower the cam follower, but in areas where the crankshaft rotates quickly, there is a risk that the cam follower may jump. There are disadvantages that must be reinforced.

The object of the present invention is to eliminate the drawbacks of conventional knockout devices, provide a knockout device that has good followability with respect to the crankshaft, and has a large pushing force.

To achieve this objective, the knockout device of the present invention has a structure in which the lifting and lowering of the knockout pin is synchronized with the rotation of the crankshaft, and the knockout pin is raised and lowered rapidly after the slide passes the bottom dead center.

Next, the structure and operation of an embodiment of the present invention will be explained based on the drawings. The eccentric point of a shaft 1 that rotates coaxially with a crankshaft (not shown) or synchronously by a transmission mechanism such as a gear is connected to one end of a bell crank 3 by a link 2, and the upper end of a connecting rod 4 is connected to the other end. Connecting. The bell crank 3 is pivoted downward on a support shaft 5 provided at the rear lower part of the shaft 1, one end of which swings evenly in the vertical direction, and the other end swings back and forth with a small amount in the front and a large amount in the rear. The rotation of the shaft 1 is transmitted to the connecting rod 4 as a vertical motion in the form of a pulsation that is close to stopping, then a rapid rise and fall. The lower end of the connecting rod 4 is attached to the support shaft 5
Connected to the equally vertically swinging tip of a lever 7 fixed to one end of a rotating shaft 6 provided at the rear lower part of the connecting rod, converting the almost vertical vertical movement of the connecting rod into rotation of the rotating shaft 6; A lever 8 is fixed to the other end of the rotating shaft 6, and the lever 8 is swung back and forth. Further, a link 9 reciprocates almost horizontally between the upper end of the lever 8 and the upper end of an L-shaped lever 11 that swings in the front-rear direction, which is pivoted on a support shaft 10 provided in front of the rotating shaft 6.
Connect by. A knockout pin 12 is provided upright at the horizontal end of the lever 11. The knockout pin 12 is fitted into a pin guide 13 provided on the bed and guided so that the vertical movement of the knockout pin is maintained correctly and vertically.

In this way, the connecting rod 4 is linked to the other end of the bell crank 3, which swings forward slightly and rearwardly, and rotates the shaft 1.
Despite one eccentric rotation, the slide moves rapidly up and down after passing the bottom dead center due to minute pulsations that are close to stopping, but the knockout pin 12 moves up and down following the connecting rod 4.

FIG. 3 is a diagram showing the movement relationship between the slide and the knockout pin. Immediately after the slide passes the 180° point (bottom dead center), the knockout pin begins to rise, and at the 270° point while the slide is in the ascending process, the knockout pin reaches top dead center and continues to descend. If the motion correlation is disrupted due to some reason, such as a cam follower flying, interference will occur between the slide and the knockout pin, but in this invention, each element is mechanically connected, so the stroke of the slide and the knockout pin are There is no time lag between the vertical movement of the pins, and perfect synchronization can be maintained to allow safe pressing work. In addition, since there is no friction element such as a cam follower, the rotational force of the shaft 1 is transmitted to the knockout pin without being reduced or lost on the way, and even if there is a slight increase in weight of the workpiece, knockout will not be affected. There isn't.

[Brief explanation of the drawing]

FIG. 1 is a front view of the device of the present invention, FIG. 2 is a plan view of the lower part of the device, and FIG. 3 is a correlation diagram of the motion curves of the slide and the knockout pin. 1 is a shaft that rotates coaxially with the crankshaft, 2 is a link, 3 is a bell crank, 4 is a connecting rod, 5 is a support shaft,
6 is a rotating shaft, 7 is a lever, 8 is a lever, 9 is a link, 10 is a support shaft, 11 is an L-shaped lever, 12 is a knockout pin, and 13 is a pin guide.

Claims (1)

[Scope of utility model registration request] In a mechanical press, an eccentric point of a shaft 1 that rotates coaxially with the crankshaft or synchronously rotated by a transmission mechanism such as a gear, and one end of a bell crank 3 that swings vertically evenly and is pivoted downward to a support shaft 5 at the lower rear. The other end of the bell crank 3 is connected to the bell crank 3 by a link 2, and the other end of the bell crank 3 swings in the forward and backward directions. A lever 8 is connected to the top end of the lever 8 by a connecting rod 4 that moves up and down almost vertically, and is fixed to the other end of the rotating shaft 6 and swings back and forth. Glyph lever 11
The L-shaped lever 1 is connected to the upper end of the L-shaped lever 1 by a link 9 that reciprocates almost horizontally.
A knockout pin 12 is erected at the tip of the slider 1, and the knockout pin 12 is fitted into a pin guide 13 to synchronize the rise and fall of the knockout pin 12 with the crankshaft and to quickly move the knockout pin 12 after passing the bottom dead center of the slide. A press knockout device characterized by having a structure that allows it to be lifted and lowered.