JPH11300754A - Safety device for mold clamping apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a safety device which is simple in constitution and can take measures to prevent mold clamping and mold opening. SOLUTION: The end face 42 of a stopper rod 33 is brought into contact with a slide block 37 to prevent mold clamping, and the neck part of the stopper rod 33 is made to face the small-diameter part of a potbellied hole 36, and a jaw 44 is brought into contact with the upper surface of the slide block 37 when the stopper rod 33 is brought down to prevent mold opening. In this way, only by fitting a safety device of simple structure to a mold clamping apparatus, measures for preventing mold clamping and mold opening can be taken to attempt the safety of work and operation.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a safety device suitable for a mold clamping device such as an injection molding machine, a compression molding machine or a transfer machine, and more particularly to a vertical type clamping device.

[0002]

2. Description of the Related Art FIGS. 5A and 5B are principle diagrams of a conventional double-link toggle-type mold clamping device. (A) is a state where the movable platen 102 is separated from the fixed platen 101 by moving the movable platen 102 away from the fixed platen 101,
Indicates that the mold has been opened. When closing the mold,
Toggle links 105, 105 in the shape of a cylinder
The movable plate 102 is raised by extending the movable plate 102 in the shape of “I”. 107 is a tie bar and 108 is a pressure receiving board.
(B) shows a mold-clamped state, that is, a state in which the movable mold 104 is combined with the fixed mold 103, and this state is referred to as the movable platen 1.
02 and the toggle links 105, 105. In this (b), injection molding is performed, and (a) and (b) are repeated so that the mold is opened and the molded product is taken out in (a).

[0003] In the above (a), when taking out a molded product, setting an insert product in a die, exchanging the fixed die 103 and the movable die 104, and checking, etc., the fixed plate 101 and the movable plate 102 are connected to each other. Must be kept at a predetermined size. This is to ensure work safety. The safety measure at this time will be referred to as a mold clamping prevention measure. Further, in the above (b), it is necessary to prevent an unexpected mold opening due to an inadvertent mold opening or a failure of the movable mold or the movable plate or the like due to its own weight. That is, the fixed board 101 and the movable board 102
Must be kept at a predetermined size.
The safety measure at this time will be called a mold opening prevention measure.

Japanese Patent Application Laid-Open No. Hei 5-338003 discloses a technique relating to such a mold clamping / mold opening prevention technique, which is disclosed in FIG. 1 of the publication. As shown in the figure, the stopper rod 3 is extended from the fixed platen 1, and the rack 4 is cut on the stopper rod 3. The upper platen 2 is positioned with respect to the fixed platen 1 by engaging a lock claw 6 provided on the upper platen 2 with the rack 4 by a pressing action of the hydraulic cylinder 10.

[0005]

The teeth of the rack 4 basically have a chevron-shaped cross section, as do the teeth of the locking pawl 6. When the lock claw 6 is engaged with the rack 4 and an axial force is applied to the rack 4, the slopes of the mountains slide and push each other. As a result, the rack 4 tends to separate from the lock claw 6, and the lock claw 6 Attempts to move away from rack 4. In order to prevent this, the locking pawl 6 must be pressed against the rack 4 with a large force. To that end, it is believed that a strong hydraulic cylinder 10 was provided instead of a pneumatic cylinder, but the safety device must be made generally robust to withstand hydraulic pressure. In addition, since the teeth of the rack 4 are easily crushed, the teeth must be made sufficiently large, and the diameter of the stopper rod 3 must be increased accordingly. Therefore, the safety device disclosed in the above publication has a complicated structure, is large, is expensive, and cannot be said to be easy to adopt.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a safety device with a simpler structure and capable of taking measures to prevent mold clamping and mold opening.

[0007]

In order to achieve the above object, according to the present invention, there is provided a safety device for a mold clamping device which spans a fixed plate and a movable plate of a mold clamping device for clamping a molding die.
In this safety device, a stopper rod having a small-diameter neck portion and a large-diameter head portion at one end, and a large-diameter portion larger than the head portion and a small-diameter portion smaller than the head portion and larger than the neck portion are connected. And a moving means for sliding the slide block. The base of the stopper rod is attached to one of the fixed plate and the movable plate, and the slide block is slidably attached to the other and moved. The measures to prevent mold clamping that attach the means and prevent the movable plate from facing the fixed plate when the movable plate is opened,
To prevent the movable platen from moving toward the open side during mold clamping, the neck opening should be applied to the small-diameter portion of the slide block. It is characterized by having a structure that is implemented by facing.

[0008] A mold clamping prevention measure is taken by the head portion of the stopper rod and the slide block, and a mold opening prevention measure is taken by the neck portion of the stopper rod and the slide block. Since the safety device includes the stopper rod, the slide block, and the moving means, the number of constituent members is small, and the safety device is simple as a whole.

[0009]

Embodiments of the present invention will be described below with reference to the accompanying drawings. The drawings should be viewed in the direction of reference numerals. FIG. 1 is a front view of a mold clamping device provided with a safety device according to the present invention. A mold clamping device 1 includes a base 2 and tie bars 3. And a fixed platen 4 attached to the upper ends of the tie bars 3...
And the tie bar 3 so that it goes up and down toward the fixed platen 4
A movable plate 5 attached to the movable plate 5, a toggle mechanism 10 for moving the movable plate 5 up and down, a projection mechanism 20 attached to the movable plate 5,
It consists of a safety device 30 bridged between the fixed platen 4 and the movable platen 5, and details will be described below.

The toggle mechanism 10 includes a pressure receiving plate 11 fixed to the base 2 and a first vertically disposed center of the pressure receiving plate 11.
Screw 12 and nut 1 meshed with this first screw 12
3, a lever 14L extending left and right from the nut 13,
The left and right toggle links 15L and 15R driven by 14R (L indicates left and R indicates right; the same applies hereinafter). The first screw 12 is connected to the first belt 17 and the first belt 17 by a toggle drive motor (not shown). By turning through the pulley 18, the nut 13 can be raised and lowered to drive the toggle links 15L and 15R from the character "" to the character "I" or vice versa. This operation is the same as that described with reference to FIGS.

The projecting mechanism 20 has a second screw 23 attached to a bearing plate 22 supported by pins 21 and 21 extending downward from the bottom of the movable platen 5, and the second screw 23 is connected to a lifting plate 25 via a nut 24. And push pins 26,
The push pins 26, 26 are made to protrude above the movable platen 5 by turning the second screw 23 through the second belt 27 and the pulley 28. And project the molded product from a molding die (not shown).

FIG. 2 is an enlarged view of a main part of the safety device according to the present invention. The safety device 30 has a small-diameter neck portion 31 such as the upper half of a kokeshi and a large-diameter head portion 32 at one end. A slide block 37 having a stopper rod 33, a large diameter portion 34 larger in diameter than the head portion 32, and a dharma hole 36 in which a small diameter portion 35 smaller in diameter than the head portion 32 and larger than the neck portion 31 are connected. It comprises an air cylinder 38 as a moving means for sliding the slide block 37, and a bracket 39 for attaching the slide block 37 and the air cylinder 38 to the fixed platen 4.

The bracket 39 is a gutter-shaped fitting, and is a component that supports the slide block 37 so as to be able to move horizontally.
However, the shape of the bracket 39 is arbitrary. Alternatively, since the fixing plate 4 is sufficiently thick, the bracket 39 may be omitted by making a horizontal hole in the fixing plate 4 and storing the slide block 37 in the horizontal hole. Returning to FIG. 1, the base of the stopper rod 33 is attached to the movable platen 5 with nuts 41, 41, and the slide block 37 is disposed at a position facing the head 32 of the stopper rod 33. Note that the safety device 30 may be turned upside down, the stopper rod 33 may be attached to the fixed platen 4, and the slide block 37 may be attached to the movable platen 5.

The operation of the above-described safety device will now be described. 3 (a) to 3 (d) are illustrations of a mold clamping prevention measure of the present invention. (A) corresponds to a view of the safety device 30 of FIG. 1 as viewed from the left, and shows that the head portion 32 can be seen through the large diameter portion 34 of the dharma hole 36 as shown in (b). In this state, the head section 32 can move up and down without being hindered by the slide block 37. Therefore, in (c), the slide block 37 is retracted as indicated by an arrow as a mold clamping prevention measure. As a result, as shown in FIG.
Is overlapped with the head portion 32. The small diameter portion 35 is so small that the head portion 32 does not pass.
It is assumed that the gap between the slide block 37 and the front end surface 42 of the head 32 is L3 in (c). L3 of this gap
The movable platen 5 is raised until the value of the movable platen 5 becomes zero, but the lifter cannot be raised any further since the stopper rod 33 hits the slide block 37. Therefore, the work between the fixed platen 4 and the movable platen 5 can be performed with confidence when fully opened.

FIGS. 4 (a) to 4 (f) are illustrations of a mold opening prevention measure of the present invention. (A) also corresponds to a view of the safety device 30 in FIG. 1 as viewed from the left, and as shown in (b), the head portion 32 faces the large-diameter portion 34 of the dharma hole 36. In (c), when the movable platen 5 is raised for mold clamping, the stopper rod 33 is moved to the darma hole 36 and the hole 4 of the fixed platen 4 as shown by an arrow.
3, the mold clamping is completed when the neck portion 31 is hooked on the dharma hole 36. (D) is the same as (b).

In (e), the slide block 37 is retracted as shown by the arrow. Thus, the small diameter portion 35 prevents the head portion 32 from descending as shown in FIG. Therefore, when the gap L4 becomes zero in (e), the jaw 44 of the head portion 32 hits the upper surface of the slide block 37 and does not lower thereafter. If the first belt 17 shown in FIG. 1 is exhausted, braking will not be effective, and the movable platen 5 may move down together with a movable mold (not shown). However, the lowering of the movable platen 5 can be prevented by the operation of FIG.

Therefore, the present invention is suitable for a vertical mold clamping device, and is particularly suitable for an electric mold clamping device. However, the present invention may be applied to a mold clamping device or a horizontal clamping device using elements other than the belt and the screw as driving members.

[0018]

According to the present invention, the following effects are exhibited by the above configuration. According to a first aspect of the present invention, a mold clamping prevention measure is taken by a stopper rod head and a slide block, and a mold opening prevention measure is taken by a stopper rod neck and a slide block. Since it is composed of the rod, the slide block and the moving means, the number of constituent members is small and the whole is simple. Therefore,
Just by attaching the safety device of the present invention having a very simple structure to the mold clamping device, it is possible to take both mold clamping and mold opening measures,
Work safety and operation safety can be achieved.

[Brief description of the drawings]

FIG. 1 is a front view of a mold clamping device provided with a safety device according to the present invention.

FIG. 2 is an enlarged view of a main part of the safety device according to the present invention.

FIG. 3 is an explanatory view of a mold clamping prevention measure of the present invention.

FIG. 4 is an explanatory view of a mold opening prevention measure of the present invention.

FIG. 5 is a principle view of a conventional double link toggle type mold clamping device.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Clamping device, 2 ... Base, 3 ... Tie bar, 4 ... Fixed plate,
5 movable plate, 10 toggle mechanism, 20 projecting mechanism, 30
... Safety device, 31 ... Neck, 32 ... Head, 33 ...
Stopper rod, 34 ... Large diameter part, 35 ... Small diameter part, 36 ...
Dharma hole, 37: slide block, 38: moving means (air cylinder), 42: distal end face of neck, 44: jaw of neck.

Claims (1)

[Claims] 1. A safety device for a mold clamping device that bridges a fixed plate and a movable plate of a mold clamping device for clamping a molding die, wherein the safety device has a small-diameter neck portion and a large-diameter head portion at one end. A slide block provided with a stopper rod provided with the above, a large-diameter portion larger in diameter than the head portion, and a dharma hole in which a small-diameter portion smaller in diameter than the head portion and larger in diameter than the neck portion are continuous. Moving means, the base of the stopper rod is attached to one of the fixed board and the movable board, and the slide block is slidably attached to the other, and the moving means is attached. When the movable board is opened, the movable board becomes a fixed board. In order to prevent the movable platen from moving toward the open side during mold clamping, the mold clamping prevention measures to prevent the movable plate from being directed toward the small block of the slide block are carried out. Open Prevention, safety devices of the mold clamping apparatus being characterized in that the structure to be implemented in made to face the neck portion to the small diameter portion of the slide block.