JPH0423622Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a safety door device for an injection molding machine or the like.

[Conventional technology]

Generally, in a horizontal injection molding machine consisting of a fixed platen and a movable platen that is movable via a diver, the fixed mold and the movable mold are attached to the fixed platen and the movable platen, respectively, and the movable mold faces the fixed mold. The mold moves at high speed, and is finally closed by a strong static pressure.

On the other hand, in recent years, large injection molding machines have been used frequently, and as a result, people have to enter the machine during mold opening to inspect large and complex molds or to inspect and repair the injection molding machine itself. There are more opportunities. Also,
In large-sized injection molding machines, molded products are increasingly being taken out directly by hand, without using a take-out machine. In this case, if the size and weight of the molded product are large, it is often impossible to remove it without inserting one's body into the machine. Under such circumstances, work is normally done with the safety door open, but if the movable platen were to accidentally close during this work, it would be extremely dangerous. For this reason, a safety door or safety cover is installed on the outside of the movable part, and this safety door device prevents the mold clamping device from moving when the safety door is open, or makes it impossible to confirm that the safety door is closed. It is common practice to provide an interlock circuit that interrupts the mold clamping circuits, such as electrical and hydraulic circuits, so that the mold clamping device cannot be operated unless the mold clamping device is activated.

However, as the size of the machine increases, the size and weight of the safety door also increase, the kinetic inertia also increases, and the opening/closing force and opening/closing stroke become larger. Since the safety door is opened and closed manually,
This imposes a considerable labor burden on the operator, causes a large loss in cycle time, and reduces productivity, so there is an increasing demand from users to automate the operation of safety doors by borrowing power from air cylinders, etc. And some of them have been materialized.

[The problem that the idea attempts to solve]

However, when using an injection molding machine equipped with such an automatically opening/closing safety door and an interlock circuit, if someone is inside the machine, there may be some malfunction or other people may have to make sure that the machine is safe. If the closing operation of the safety door is triggered by operating the safety door closing switch without opening the door, the interlock circuit of the machine that functions when the safety door is open is released, and the mold closing movement , contains a defect that poses a risk of causing a serious accident that could harm people inside the machine.

The purpose of this invention is to prevent the interlock circuit from being released by preventing the safety door from completely closing even if the safety door closes by mistake during work with the safety door open. Our objective is to provide safety door devices for aircraft, etc.

[Means for Solving the Problems] In order to achieve the above object, the present invention provides a safety device which is provided on the outside of a mold clamping device of an injection molding machine and which is closed by horizontal movement toward the fixed platen side of the injection molding machine. In a safety door device for an injection molding machine, etc., comprising a door and an interlock mechanism that interrupts an operating circuit of the mold clamping device when the safety door is opened, the safety door is attached to a fixed platen of the injection molding machine. A stopper rod which is rotatably supported in a horizontal direction by its own weight with one end of the side as a free end, and has a locking pin protruding from its intermediate portion, and a stopper rod for rotating the stopper rod. an operating lever pivotally supported on the other end of the stopper rod, and a control lever placed below the stopper rod on the stationary plate by a predetermined distance in the horizontal direction while being constantly biased in the direction in which the safety door opens. A movably supported cam; When the cam is positioned closest to the safety door, a locking pin of the stopper bar is placed so that the stopper bar maintains a predetermined angle with respect to the horizontal. a safety door closing prevention mechanism consisting of a projection integrally provided on the central upper surface of the cam, and an end of the safety door on the fixed platen side facing the safety door closing prevention mechanism. When the stopper bar is horizontal, the safety door abuts one end surface of the stopper bar at a position that leaves a predetermined opening degree, and the stopper bar maintains the predetermined angle. When the safety door is moved in the closing direction, it does not come into contact with one end surface of the stopper rod,
A contact member having a contact surface that contacts an end surface of the cam on the safety door side and moves the cam by an intermediate distance of the predetermined distance in a direction opposite to the urging direction is fixedly provided. It is characterized by

[Function] With the safety door open, when the stopper rod is rotated by a predetermined angle from the horizontal position using the operating lever, the cam that is biased in the direction of opening the safety door moves to the furthest side of the safety door. Since the protrusion of the cam rests on the locking pin of the stopper rod, the stopper rod maintains a predetermined angle with respect to the horizontal. When the safety door is closed in this state, the contact surface of the contact member of the safety door does not contact the stopper rod but the cam, and the safety door pushes the cam in the opposite direction to the biasing direction (when the safety door is closed). direction). As a result, the locking pin comes off the protrusion and moves away from the horizontal position due to its own weight, but one end of the stopper rod remains placed on the upper surface of the abutment member.

When the safety door is opened from this state, the stopper rod comes off the top surface of the abutment member as the safety door moves, and the stopper rod rotates to a horizontal position due to its own weight. When attempting to close the safety door at this time, the abutting member abuts one end surface of the stopper bar at a position before the safety door is completely closed, leaving the safety door open at a predetermined degree. Therefore, since the interlock mechanism is not released, there is no possibility of accidentally operating the machine.

[Embodiment] An embodiment of the safety door closing prevention device according to the present invention will be described below with reference to the drawings.

FIG. 1 is an overall configuration diagram of a safety door equipped with an automatic opening/closing means using an air cylinder as a driving source and a safety door closing prevention mechanism according to the present invention. FIG. 5 is a perspective view showing one form of the contact member; FIG. .

As shown in FIG. 1, both ends of an upper rail 3 and a lower rail 4 are fixed to a fixed platen 1 and an end housing 2, respectively, of a mold clamping device as a movable part of an injection molding machine. On rails 3 and 4,
The safety door is movably mounted. An air cylinder 9 is fixed to the upper rail 3, and the tip of a piston rod 10 of the air cylinder 9 is connected to the safety door 6 via a bracket 11. At the lower end of the operation panel 8 attached to the fixed board 1, there are a door open operation switch 12 and a door close operation switch 13 for switching and operating an electromagnetic four-way switching valve (not shown) for driving the air cylinder 9. is arranged,
By operating these operation switches 12 and 13, the safety door 6 can be automatically opened and closed. A stopper 7 for determining the closing position of the safety door 6 is fixed to the end of the lower rail 4 on the fixed platen 1 side.

In addition, the mold clamping device includes an interlock circuit (not shown) that shuts off the operating circuits such as the electric circuit and hydraulic circuit of the mold clamping device so that the mold clamping device cannot operate when the safety door is open. It is provided.

The safety door device of this embodiment will be explained below with reference to FIG.

The safety door device of this embodiment includes a safety door closing prevention mechanism 15 disposed on a fixed platen 1 and a contact member provided on a safety door 6 that cooperates with the safety door closing prevention mechanism 15. It consists of a plate 30.

The safety door closing prevention mechanism 15 includes a rotary shaft support 18 protruding from a fixed frame 16 fixed to the fixed platen 1.
A stopper rod 1 supported rotatably around
7 and the fixed frame 16 located below the stopper rod 17 so as to be able to move a limited distance in the horizontal direction.
The main components include a cam 21 which is supported by a cam 21 having a protrusion 26 on the upper surface of the central part thereof, and an operating lever 25 which is pivotally supported on the end of the stopper rod 17 on the side opposite to the safety door and rotates the stopper rod around its rotation axis 18. element.

The position of the rotary support shaft 18 relative to the stopper rod 17 is determined such that the stopper rod 17 rotates counterclockwise in the drawing by its own weight with one end on the side of the safety door 6 serving as a free end. Stopper stick 1
7 is rotated by a stopper (not shown) at a predetermined angle from 0° to the horizontal in the clockwise direction shown in the drawing, for example, approximately
It is regulated to allow rotational movement within a range of 5.5°. A buffer body 20 is provided at one end of the stopper rod 17.
is fixed. Further, in the middle part of the stopper rod 17, there is a pin 19 as a locking pin which is placed on the tip of a protrusion 26 when the cam 21 moves furthest toward the safety door 6 in the open position of the safety door 6, which will be described later. Fixed.

A pair of elongated holes 23-1 and 23-2 having a predetermined horizontal length are formed in the cam 21. A pair of screws 22-1, 22-2
By loosely fitting the cam 21, the cam 21 can horizontally move within a range limited by the horizontal length of the elongated holes 23-1 and 23-2. Further, the cam 21 is biased horizontally toward the safety door 6 by a spring 24, and is elastically biased.

On the other hand, the backing plate 30 is fixedly installed at the end of the safety door 6 on the fixed platen 1 side facing the safety door closing prevention mechanism 15 described above, and an example of its structure is shown in FIG. It has a front surface 30a and an upper edge 30b on the fixed platen 1 side.

The relative positions of this backing plate 30, stopper rod 17, and cam 21 are configured as follows. That is, (1) In the safety door closing limit position shown in FIG. The safety door 6 is moved by an intermediate distance in the direction of closing the safety door 6. The stopper rod 17 rotates counterclockwise due to its own weight, so that the stopper rod 17 moves against the backing plate 3.
0 on the upper edge 30b (see FIG. 5),
The pin 19 of the stopper rod 17 and the cam 21
It is not engaged with the protrusion 26 of.

(2) From the safety door closed position in Figure 2, safety door 6
As the door is moved in the opening direction, that is, to the left in the figure, the stopper rod 17 comes off the upper edge 30b (see FIG. 5) of the backing plate 30 and rotates counterclockwise until it is horizontal, and the safety door closing prevention mechanism 15
In this case, the safety door is prevented from closing as shown in FIG. In FIG. 3, the safety door 6 is opened at the front surface 30a of the backing plate 30 at a position where a predetermined opening degree is left.
comes into contact with the warming body 20 of the stopper rod 17.

(3) In the safety door opening position shown in FIG. 4, when the operating lever 25 is pulled downward, the stop is pushed onto the protrusion 26 of the cam 21 that is most biased toward the safety door 6 by the spring 24. Pin 1 of rod 17
9 is placed and pressed, and the stopper rod 17 assumes a posture at a second angle with respect to the horizontal.

Next, the operation of this embodiment will be explained.

First, as shown in FIG. 4, when the lever 25 is pulled downward with the safety door 6 open and the stopper rod 17 is rotated 5.5 degrees clockwise from the horizontal position, the cam 21 is moved by the spring 24. Even if the spring force moves the lever 25 to the side closest to the safety door and the operating lever 25 is released, the pin 19 is placed on the protrusion 26, so the stopper rod 17 remains at an angle of about 5° (second angle) to the horizontal. is maintained. This position is a state in which the closure prevention of the safety door 6 is released.

When the safety door 6 is closed from this state, the backing plate 3
0, the safety door 6 does not come into contact with the stopper rod 17.
The contact plate 30 contacts one end surface of the cam 21 a little before the closing limit position of the safety door 6, and further moves the cam 21 in the closing direction of the safety door 6 at the closing limit position of the safety door 6. As a result, pin 1 of the stopper rod 17
9 comes off from the protrusion 26 of the cam 21, and the stopper rod 1
7 rotates counterclockwise due to its own weight, and the backing plate 3
0 (see FIG. 5) (state shown in FIG. 2). At this time, the stopper rod 17 is held at an angle of about 3.5° (first angle) with respect to the horizontal.

When the safety door 6 is opened from the closed state, the stopper rod 17 comes off the upper edge 30b of the backing plate 30 and rotates to a horizontal position due to its own weight, as shown in FIG. This state is the state in which the safety door is prevented from closing. When attempting to close the safety door 6 in this state, the front surface 30a of the backing plate 30 and the buffer body 20 of the stopper bar 17 come into contact with each other at a position where the safety door 6 remains open to a predetermined degree, and the safety door 6 is completely closed. cannot be closed.

In this way, when the safety door 6 is opened, the safety door close prevention state is automatically set, and the safety door 6 is accidentally opened.
Since the safety door 6 cannot be completely closed even when the operator attempts to close the safety door 6, the interlock circuit, which is released only when the safety door 6 is closed, is in a functional state and the safety of the operator is ensured.

Note that the above first and second angles are
1 length of long holes 23-1, 23-2 and protrusion 2
6, the position of the pin 19 of the stopper rod 17, the length of the backing plate 30 in the vertical direction, etc. can be arbitrarily set by appropriately selecting a combination.

[Effects of the invention] As explained above, the present invention includes a stopper rod that rotates under its own weight, a cam that regulates the posture of the stopper rod, and a stopper rod that contacts the stopper rod or abuts the cam depending on the posture of the stopper rod. By having a contact member, when the safety door is opened, the safety door is automatically set to the state to prevent closing of the safety door, so even if the safety door moves in the closing direction while a worker is inside the machine. , the safety door is stopped leaving a predetermined opening from the closed limit position, and the interlock mechanism, which is released only at the closed limit of the safety door, is maintained in a functional state.
For this reason, the machine does not operate during work, and
Effective in preventing serious accidents.

Furthermore, since the system is purely mechanically configured so that the setting state of the safety door closing prevention state can be visually confirmed, it is possible to give the operator a sense of security.

[Brief explanation of drawings]

FIG. 1 is an overall configuration diagram of a safety door equipped with an automatic opening/closing means using an air cylinder as a driving source and a safety door closing prevention mechanism according to the present invention. FIG. 5 is a perspective view showing one form of the contact member; FIG. . 1...Fixed plate, 6...Safety door, 8...Operation panel, 15...Safety door closing prevention mechanism, 16...Fixed frame, 17...Stopper bar, 18...Rotation shaft, 19...Pin , 21... cam, 25... operating lever, 26... protrusion, 30... backing plate, 30a
...front, 30b...upper edge.

Claims (1)

[Claims for Utility Model Registration] A safety door that is provided on the outside of a mold clamping device of an injection molding machine and is closed by horizontally moving toward the fixed platen of the injection molding machine, and a state in which the safety door is opened. In the safety door device for an injection molding machine, etc., which is equipped with an interlock mechanism that interrupts the operating circuit of the mold clamping device, one end of the safety door side is set as a free end on the fixed platen of the injection molding machine, and the door is closed by its own weight. A stopper rod is rotatably supported in a horizontal direction and has a locking pin protruding from its intermediate portion, and a shaft is provided at the other end of the stopper rod to rotate the stopper rod. a supported operating lever; a cam supported below the stopper bar of the stationary plate so as to be movable a predetermined distance in the horizontal direction while always being biased in the opening direction of the safety door; is integrally mounted on the central upper surface of the cam on which the locking pin of the stopper bar is placed, with the stopper bar maintained at a predetermined angle with respect to the horizontal when the stopper bar is located closest to the safety door. and a safety door closing prevention mechanism comprising a protrusion provided therein, and the stopper bar is in a horizontal state at a portion of the end of the safety door on the fixed plate side that faces the safety door closing prevention mechanism. Then, when the safety door comes into contact with one end surface of the stopper bar at a position where a predetermined opening degree remains, and the safety door is moved in the closing direction with the stopper bar maintaining the predetermined angle. , does not come into contact with one end surface of the stopper rod,
A contact member having a contact surface that contacts an end surface of the cam on the safety door side and moves the cam by an intermediate distance of the predetermined distance in a direction opposite to the urging direction is fixedly provided. A safety door device for injection molding machines, etc., featuring: