JPH03216255A - Clamping device for molds, etc. - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a clamping device for a mold, etc., and more specifically, a mold for a mold such as a die casting machine or an injection molding machine, or a mold for a processed product in a molding machine. In particular, it relates to clamping devices for molds, etc., which are configured to hold down molds, etc. with rotating claws. [Prior Art] A conventional example of such a structure is shown in Figs. 3 and 4. In Figure 3, l is a mold mounting plate, specifically a fixed plate or a movable plate. There are a total of four columns 2 on the periphery of this mold mounting board l, and a plurality of mold clamping devices 3 are installed at positions apart from the columns 2, for example, two at opposite positions. Attached, la is the mold. The details of this mold clamping device 3 are shown in Fig. 4.
Reference numeral 13 in FIG. 4 is a presser pawl, which is rotatably supported on the base 17 via a shaft l4. The rear side of the presser claw 13 is housed in a casing l5, and a compression spring 16 is elastically loaded between it and the top plate of the casing l5.
The presser claw l3 is given a rotational habit in the clockwise direction in the figure. A piston 18 is fitted into a base l7 located below the rear part 13b of the presser claw l3 so as to be movable up and down. A hemispherical projection l9 is protruded from the upper end of the piston l8, and is slidably fitted into a spherical seat 13a provided on the lower surface of the rear part 13b of the presser claw l3. The lower part of the piston l8 is in contact with the stepped part 17a of the base l7,
However, the lower limit of this step 17a is regulated.
does not necessarily have to be provided. A protrusion 20 having an inclined surface 20a on the lower surface projects from the rear end side of the piston l8. This protrusion 20 is arranged within one hydraulic chamber 21 formed within the base 17. The lower surface of the hydraulic chamber 2l is raised to form a horizontal surface, and a piston 2l is slidably fitted into the other cylindrical hydraulic chamber 21a. It comes into contact with the stepped portion 2lb provided at the top, and its forward movement limit is restricted. Piston rod 22 on the hydraulic chamber 21 side of this piston 22
A wedge 23 is integrally provided at the tip a.
The piston rod 22a in the hydraulic chamber 21 and the lower surface of the wedge 23 are provided so as to be slidable with respect to the horizontal surface portion 21c of the lower surface of the hydraulic chamber 21, and the inclined upper surface of the wedge 23 moves against the protrusion 20 according to the movement. Contact with the lower inclined surface 20a of the.
It is now possible to leave. Therefore, the protrusion 20 and the wedge 23 form a wedge mechanism. Further, a guide rod 24 is provided protruding from the rear end side of the piston 22. [Problems to be Solved by the Invention] However, when the conventional clamping device for molds, etc. configured in this way is used for a long period of time, rust may develop on the shaft that rotates the presser claw, and the presser foot may become damaged. When rust forms on the sides of the claws, it often becomes impossible to move the presser claws using only the elastic force of the springs, making it difficult to repeatedly and smoothly clamp and release molds, etc. In order to increase the elastic force of the spring, it would be possible to use a large spring, but this had the disadvantage that it was not possible to increase the force of the spring due to space constraints. [Means for Solving the Problems] In order to solve these problems, the present invention provides a presser foot that has a tip that can clamp a mold, etc., and that is biased with rotational force in the direction of releasing the clamp. A pawl is rotatably provided on a base, a piston is provided at the rear of the presser pawl through a spherical contact part in a state that intersects with the presser pawl, and the inclined part provided at the rear end of the piston is connected to one side of the hydraulic cylinder. A mold, etc., which is located in a chamber and is slidably provided in the hydraulic chamber, and which is integrated with the piston of the hydraulic cylinder, and forms a wedge mechanism with the wedge and the inclined part of the rear end of the piston. In the clamp device, a cylinder is disposed at the rear of the presser pawl, and a sliding member that fits into the cylinder and is slidably moved by working fluid is connected to the casing provided on the outer periphery of the clamp device and the presser pawl. The configuration was such that it was placed between [Function] When it is desired to clamp a mold using the clamping device of the present invention, hydraulic oil is introduced into the hydraulic chamber and the wedge is moved.
When the upper inclined surface of the wedge and the lower inclined surface of the protrusion are brought into contact, the protrusion and the wedge form a wedge mechanism, so the presser claw rotates counterclockwise around its axis, and the tip of the presser claw rotates the metal. Clamp the mold. Conversely, when hydraulic oil is introduced to the head side of the sliding member, the clamp is released. [Example] Figures 1 and 2 show an example of the clamping device for molds, etc. according to the present invention. A vertical cross-sectional view of the clamping device when installed between the top plate of the casing, FIG. 2 shows another clamping device similar to FIG. 1, and FIG. FIG. 2(b) is a partially enlarged vertical cross-sectional view of a clamping device that is equipped with a piston and a piston rod and is configured to release the clamp by pressing the rear end side of the presser claw. FIG. 2(b) shows the piston in FIG. 2(a). The plan view of each is shown. The details of the present invention will be explained below with reference to FIGS. 1 and 2, which are examples. In addition, 13, 13a, 14, 15, 1
7, 17a, 18, 19, 20. 20a, 21, 21a
, 2lb, 21c, 22, 22a and 24 are the same as those described in the conventional example, so their explanation will be omitted and only the different parts will be explained. First, the clamp device 3 of this embodiment shown in FIG. 1 uses a ram 8 as a sliding member instead of the conventional compression spring l6 shown in FIG. That is, a part of the rear part 13b side of the presser claw l3 is carved to form a cylinder 9, and the ram 8 is slidably fitted into the cylinder 9.
Hydraulic oil is introduced into the ram head 8b side from a conduit (not shown) to push up the ram 8, and due to the action of the hydraulic oil, the rear part 13b of the presser pawl 13 is rotated clockwise, and the tip of the presser pawl l3 is rotated clockwise. Mold 1 by 13c
The structure is such that the holding part l3 of a is released from the mold 1a and the clamped state is released. An appropriate number of oil rings are attached to the circumference of the ram 8 to prevent pressure oil from leaking between the ram 8 and the cylinder 9 when hydraulic oil is introduced into the ram head 8b. On the other hand, on the ram bottom 8c side, in order to ensure that the ram 8 slides, a convex portion 1 is provided at the location where the ram 8 rises due to the pressure oil introduced into the ram head 8b and comes into contact with the top plate l5.
It is carved so that it fits loosely with 5a. Next, the operation of this embodiment configured as above will be explained. As shown in FIG. 1, when no hydraulic pressure is applied to the hydraulic chamber 2l and the wedge 23 moves forward together with the piston 22, the presser pawl l3 moves the hydraulic oil introduced into the ram head 8b. The presser claw is moved clockwise around the axis l4 by the pressing force, and the tip 13c of the presser claw is
is located away from the wedge part of the mold. In this state, mold replacement work is performed. When clamping the mold, hydraulic oil is supplied into the hydraulic chamber 21, the piston 22 is moved back to the right in FIG. Push up and press the presser claw 1 through the hemispherical protrusion 19.
Push up the rear end of 3. Then, the presser pawl 13 pushes the ram 8 upward by a stroke S and rotates counterclockwise in FIG. 1, and the tip of the presser pawl 13 strongly presses down the presser part of the mold. During this clamping, the wedge 23 is attached to the inclined surface 2 of the protrusion 20.
When 0a is pressed strongly, a frictional force acts, but since hydraulic oil is supplied to the hydraulic chamber 21, this hydraulic oil acts as an interstitial oil, and the frictional force is significantly reduced. Therefore, the output of the hydraulic power source that operates the piston 22 may be small. In addition, when hydraulic pressure is applied, it not only pushes the piston 22 but also acts in the direction of raising the piston 18, so the imitation effect of the wedge 23 increases and the presser claw l
3 enhances the clamping effect. Incidentally, even when the hydraulic oil in the hydraulic chamber 21 is not discharged or no pressure is applied in the clamped state, the wedge 23
The clamped state is not released because of the wedge effect. If you want to release the clamped state, pinch the screw 22 and apply hydraulic pressure to the hydraulic chamber 21a on the opposite side of the hydraulic chamber 2l. The piston 22 will move forward to the position where it contacts the stepped portion 2lb, and the wedge 23 will be released from the protrusion. Stay away from 20. Therefore, due to the operation of the compression spring 16, the rear end of the presser pawl l3 is pushed downward, the presser pawl l3 is moved eight times in the clockwise direction in the figure, the mold clamp is released, and the piston l8 is also brought to its lower limit. Reach. Although an embodiment of the present invention is shown in FIG. 1, the present invention is not limited to this embodiment, and a structure as shown in FIG. 2 using a piston as a sliding member may be used. That is, a cylinder 30 is provided on a part of the back surface of the top plate l5, and a piston 6 and a piston rod 7 are arranged to be slidably fitted into the cylinder 30. When the hydraulic oil is introduced via the inlet 5, the hydraulic oil passes through the notch 6a of the piston 6 and reaches the piston head side (area A on the piston head side), and then flows into the piston rod 6C.
When comparing the area with the side (area B on the piston rod side), A>B, so the piston 6 and the piston rod 7 move forward to the position shown by the chain line, and the tip of the piston rod 7 presses the rear end 13b of the presser claw. In order to do this, the presser pawl l3 is rotated clockwise in the figure, and the clamp-like IE of the mold 1a by the tip 14a of the presser pawl l3 is released. Conversely, if you want to put it in a clamped state, you can do it by the operation shown in Figure 1. [Effects of the Invention] As is clear from the above explanation, the present invention has the following effects. When clamping a mold, etc., there is always hydraulic oil in the hydraulic chamber where the wedge is located, so it acts as a lubricating oil during wedge operation, significantly reducing frictional force and reducing driving force. Also. Since the piston contacts the presser claw through the spherical contact part, the frictional force in this part is extremely small, which helps in downsizing the drive source. Furthermore, since the wedge effect acts when the clamp is held, it is not necessary to apply pressure to the hydraulic chamber where the wedge is located, resulting in energy savings. In the present invention, by using a ram type, even after long-term use, the clamped state can be easily released with a large force by introducing hydraulic oil into the ram head side of the ram chamber.

[Brief Explanation of the Drawings] Figures 1 and 2 show an embodiment of the clamping device for molds, etc. according to the present invention, and Figure 1 shows a part of the rear end side of the presser claw. Fig. 2 shows another clamping device similar to Fig. 1, and Fig. 2(a) shows the top plate of the casing. Fig. 2(b) is a partially enlarged longitudinal cross-sectional view of a clamping device in which a piston and a piston rod are provided in one part of the presser claw to release the clamp by pressing the rear end side of the presser claw. A plan view of the piston in Figure (a) is shown. Further, FIGS. 3 and 4 illustrate the conventional structure, with FIG. 1 being a front view and FIG. 2 being a longitudinal sectional view of the clamp device. l...Mold mounting board, la...Mold, 3
...Mold clamp device, 6,18.22...Piston, 6a...Notch, 7...Piston rod, 8...Ram, l3...・・・
... Presser claw, 13b... Rear part of presser claw, 13c...
Tip of presser claw, 15...Casing, l
6...Compression spring, l7...Base,

Claims (1)

[Claims] A presser claw, which has a tip that can clamp a mold, etc. and is biased with rotational force in the direction of releasing the clamp, is rotatably provided on the base, and a piston is attached to the rear of the presser claw via a spherical contact part. A wedge provided intersecting the presser claw and provided at the rear end of the piston is located in one hydraulic chamber of the hydraulic cylinder, and a wedge integrated with the piston of the hydraulic cylinder is slidable into the hydraulic chamber. In a clamping device for a mold or the like in which the wedge and the inclined part of the rear end of the piston form a wedge mechanism, a cylinder is disposed at the rear of the presser claw,
A mold, etc., characterized in that a sliding member that fits into the cylinder and is slidably moved by working fluid is disposed between a casing and a presser claw provided on the outer periphery of the clamp device. clamping device.