JPH0611511B2 - Safety device in mold clamping device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a safety device in a mold clamping device such as an injection molding machine that mechanically blocks a mold closing operation in relation to a safety door.

[Prior Art] In a mold clamping device such as an injection molding machine, a safety door is attached to the side of the mold clamping device from the viewpoint of ensuring worker safety. Prevents mold closing motion. Also, in case of emergency, double safety measures are taken so that the mold cannot be closed mechanically unless the safety door is closed.

In a normal mold clamping device, for example, a movable plate is provided between a pair of fixed plates on a machine base so as to move back and forth, and a mold is closed by a movable plate that moves back and forth using a tie bar as a guide. A stopper member that projects the safety rod toward the fixed plate on the mounting side and receives the tip of this safety rod is provided on the fixed plate side so that it can move up and down, and a movable member of the stopper member is provided at the upper end of the safety door. When the safety door is closed, the movable member pushes the stopper member upward, so that the mold can be closed only when the tip of the safety rod is removed.

[Problems to be Solved by the Invention] However, a fixed platen and a movable platen are installed on the machine base in a pair, and the movable platen is movable back and forth with respect to the fixed platen by a pair of guide rails arranged in parallel on the machine base surface. The large mold clamping device provided does not use a tie bar that supports the load of the movable plate and also serves as a guide.Therefore, if the safety rod is projected to the fixed plate side for a long time and mounted on the movable plate, The load is applied as an unbalanced load to the movable plate, which makes it difficult to maintain the parallelism of the movable plate with respect to the fixed plate.

Further, every time the mold is replaced, it is necessary to adjust the protruding length according to the mold thickness of the mold. Most of these length adjustments fix the safety rod with a nut, so the nut is loosened.

This kind of manual adjustment work can be easily done by one person because the safety rod is not so large in a small mold clamping device, but the safety rod becomes larger and heavier as it gets larger. , It is difficult to adjust by yourself.

Further, it is desired that the position of the safety rod can be automatically adjusted in accordance with automatic die replacement due to labor saving.

The present invention was conceived in order to solve the above technical problems, and an object thereof is to prevent an unbalanced load of a movable plate due to a safety rod, and a safety rod with a large diameter as the molding machine becomes large. Even if the weight increases, it is an object of the present invention to provide a new safety device for a mold clamping device in which the safety rod and the stopper member can be easily aligned with each other and automatic adjustment can be adopted.

[Means for Solving the Problems] The feature of the present invention according to the above-mentioned object is that a fixed platen and a movable platen are installed on the machine base in a pair, and the movable platen is provided in parallel on the machine body upper surface by a pair of guide rails. Provided to the fixed plate so that it can move back and forth freely,
In a mold clamping device provided with a safety door on a side portion, an engaging device for moving a stopper member up and down with opening and closing of the safety door is provided on a lower side portion of the movable plate, and the shaft portion is penetrated through the stopper member. A safety rod having a required number of engaging steps at regular intervals is laid across the fixed plate and a bearing member on the machine base behind the movable plate, and a screw formed at the rear end of the safety rod. The shaft is screwed with the nut of the bearing member and fixed so as to be movable in the axial direction.

Another feature of the present invention is that a bearing member on the machine base is provided with a nut-shaped rotating member that is rotated by a driving device, and a screw shaft formed at the rear end of the safety rod is screwed to the movable member. , A pair of switches for confirming the elevation of the stopper member are provided in the engaging device, and at the screw shaft side rear end of the safety rod,
A pair of switches for limiting the movement of the safety rod are provided, and both switches enable automatic adjustment of the engagement position by the drive device.

[Operation] In the above configuration, when the safety door is closed, the air cylinder operates, the stopper member rises, and the engagement with the safety rod is released. Further, when the safety door is opened, air is released and the stopper member descends, so that a part of the stopper member is positioned at the engaging step portion and prevents the safety rod from moving forward together with the movable plate. Therefore, the mold closing due to the movement of the movable plate does not occur.

Further, in the case of automatic adjustment, if the descending confirmation is not made by the proximity switch while the safety door is open, the electric motor is automatically turned on to operate.

As a result, the rotating member rotates, and the screw lead causes the safety rod to move in either the front or rear direction within the setting range of the proximity switch for movement restriction, and the position of the engaging step portion is displaced to cause the stopper member to move to the safety rod position. When it falls into the annular groove, the descent is confirmed, the drive device is stopped immediately, and the adjustment of the engagement position is completed.

[Embodiment] In the figure, reference numeral 1 is a fixed plate which is installed on the upper surface of a machine base 2, and mold clamping cylinders 3 are provided at four corners.

Reference numeral 4 denotes a movable plate opposite to the fixed plate 1, which is the mold clamping cylinder 3
Tie bars 5 connected by meshing with mold clamping pistons (not shown) inside the are provided at four corners.

Such a movable platen 4 is mounted on a pair of guide rails 6 arranged on the upper surface of the machine base at right angles to the fixed platen 1, and a slider 7 is provided.
It is provided so that it can be moved back and forth through.

Reference numeral 8 denotes a horizontally-pulled safety door, which is attached to a frame 8a on a side portion which is provided over the fixed plate 1 and the rear of the movable plate 4. Reference numeral 9 denotes a mold which is divided and attached to the facing surfaces of the fixed plate 1 and the movable plate 4.

10 is a safety device, which is a safety rod 11 and an engaging device 1 on the movable platen side.
2 and the bearing portion 13 on the machine base.

The safety rod 11 is a long one, and has a required number of engaging step portions 14, 14 formed by cutting out the shaft portion in a piece shape at regular intervals, and the rear end portion is formed on a screw shaft 15. Has been done.

The engaging device 12 is provided with a stopper member 16 which can be raised and lowered in a block having a through hole fixed to the lower side of the movable platen 4, and the stopper member 16 is a piston 18 of an air cylinder 17 installed at the top of the block. Connected with. Further, as shown in FIG. 2, the stopper member 16 is provided with an insertion hole 19 for the safety rod 11.

Although not shown in the drawing, the air cylinder 17 is connected to a switching valve 20 on the machine base which is opened / closed by the safety door 8, and when the safety door 8 is closed and the switching valve 20 is opened, the air cylinder 17 is connected to the air cylinder 17. Is supplied, the stopper member 17 is moved upward together with the piston 18 which is constantly elastically pressed downward by the spring, and the engagement is released to allow the movable platen 4 to move forward.

The bearing portion 13 is composed of a support member 21 on a support body fixed on the machine base, and a nut 22 at a fixed position outside the support member.

The tip of the safety rod 11 is fixed from the side of the bearing 13 on the machine base through the stopper member 16 in the block.
Is inserted in the lower receiving member 23 and the screw shaft 1 at the rear end
Reference numeral 5 is threadedly engaged with the nut 22 and laid across the fixed platen 1 and the movable platen 4 over the machine base.

In such a safety device 10, as the safety door 8 is opened and closed, the air cylinder 17 is actuated, and the stopper member 16 engages or disengages the safety rod 11.

Further, when the mold opening position is changed by exchanging the mold and the engagement position between the engagement step portion 14 and the stopper 16 is deviated due to the change, the safety rod 11 together with the screw shaft 15 is attached to the nut 22 by a spanner or the like. Rotate and safety rod 1
Adjust 1 by moving 1 in either the front or back direction.

In the example shown in FIG. 3, the engagement position can be automatically adjusted. This safety device has a pair of confirmation proximity switches 25 and 26, which are operated by a detection rod 24 on the side of the stopper member, on the side of the block of the engaging device 12.
It is provided above and below with a predetermined interval.

The bearing portion 13 includes a fixed-position nut-shaped rotating member 27 rotatably provided inside the supporting member 21, and the supporting member 21.
Of the safety rod 11, and a chain 29 formed over the gear provided on the outer periphery of the rotating member 27 and the gear of the drive shaft end of the electric motor 28. A pair of proximity switches 3 that restrict the movement of the safety rod 11 are provided outside the positioned support member 21.
Nos. 0 and 31 are laterally arranged outward at regular intervals.

Although not shown in the drawing, the tip of the safety rod is fitted with a key or the like so that the guide rod 11 can move only in the axial direction inside the receiving member 23 on the fixed platen side.

In such a safety device, the air cylinder 17 is actuated as the safety door 8 is opened and closed, and the stopper member 16 engages or disengages the safety rod 11. This confirmation is performed by the upper and lower proximity switches 25 and 26. When the safety switch 8 is open and the lowering confirmation is not made by the proximity switch 26, the electric motor 28 is automatically switched on to operate.

As a result, the rotary member 27 rotates via the chain 29, and the safety rod 11 is axially moved forward or backward by the screw lead in the setting range of the proximity switches 30 and 31 on the bearing portion 13 side. Due to this movement, the stopper member 16 falls into the annular groove of the safety rod 11, and when the proximity switch 24 confirms the lowering, the electric motor 28 is immediately switched off and stopped, and the engagement position is adjusted to an appropriate state. .

Therefore, when the die opening position is changed by exchanging the die, and even when the die opening state is changed by the change, if the lowering of the stopper member 16 by the proximity switch 26 of the engagement device 12 is not confirmed, no labor is required, The engagement position is automatically adjusted.

[Effects of the Invention] As described above, according to the present invention, the fixed platen and the movable platen are installed on the machine base in a pair, and the movable platen is moved forward and backward with respect to the fixed platen by a pair of guide rails provided side by side on the machine base. In a mold clamping device that is freely provided and has a safety door on its side, an engaging device that moves up and down a stopper member as the safety door is opened and closed is provided on the lower side of the movable plate, and the stopper member is penetrated. hand,
A safety rod having a required number of engaging steps around the shaft at regular intervals is laid across the fixed plate and the bearing on the machine base behind the movable plate, and is formed at the rear end of the safety rod. Since the screw shaft is screwed with the nut of the bearing to be fixed movably in the axial direction, the load of the safety rod is applied unlike when the safety rod is projected from the movable plate toward the fixed plate. No
Since an unbalanced load due to the safety rod does not occur there, the parallelism of the movable platen with respect to the fixed platen is maintained for a long time in the state at the time of setting.

Further, even if the engagement position is changed by exchanging the mold, the safety rod can be moved in the axial direction for adjustment, so that it does not depend on the mold thickness and the adjustment can be performed on the machine base, so there is little danger.

Furthermore, a nut-shaped rotating member that is rotationally operated by a drive device is provided in a bearing portion on the machine base, and a screw shaft formed at the rear end portion of the safety rod is screwed to the movable member, and a stopper member is provided to the engaging device. A pair of switches for confirming the vertical movement of the safety rod are provided, and a pair of switches for limiting the movement of the safety rod are provided at the rear end of the safety rod on the screw shaft side. Since adjustment is possible and it is not necessary to manually adjust the engagement position every time the mold thickness changes, it has a feature that it is well suited as a safety device for a large mold clamping device.

[Brief description of drawings]

The drawings schematically show an embodiment of a safety device in a mold clamping device according to the present invention. FIG. 1 is a side view of the first embodiment,
FIG. 2 is a vertical sectional front view of the stopper member, and FIG. 3 is a partial side view of the second embodiment showing the engaging device in a vertical section. 1 ... Fixed board, 2 ... Machine stand 4 ... Movable board, 5 ... Tie bar, 6 ... Guide rail, 8 ... Safety door, 9 ... Mold, 10 ... Safety device, 11 ... Safety rod, 12 ...... Engagement device 13 ...... Bearing section, 14 ...... Engagement step section 15 ...... Screw shaft 16 ...... Stopper member 17 ...... Air cylinder 19 ...... Insertion hole, 20 ...... Switching valve 21 ...... Support member, 22 ... Nut 23 ... Receiving member, 24 ... Detection rod 25, 26 ... Proximity switch for up / down confirmation 27 ... Rotating member, 28 ... Electric motor 30, 31 ... Proximity switch for movement control

Claims (2)

[Claims] 1. A fixed platen and a movable platen are installed on the machine base in a paired manner, and the movable platen is provided so as to be movable back and forth with respect to the fixed platen by a pair of guide rails arranged in parallel on the upper surface of the machine base. In the mold clamping device provided with a door, an engaging device for moving the stopper member up and down with opening and closing of the safety door is provided on the lower side of the movable plate, and the required number of holes is provided around the shaft portion through the stopper member. The safety rods having the engaging step portions of at regular intervals are laid across the fixed plate and the bearing portion on the machine base behind the movable plate, and the screw shaft formed at the rear end portion of the safety rod is used as the bearing portion. A safety device in a mold clamping device, characterized in that the safety device is screwed with a nut to be fixed so as to be movable in the axial direction. 2. The safety device for a mold clamping device according to claim 1, wherein a bearing member on the machine base is provided with a nut-shaped rotating member which is rotated by a drive device, and the movable member is provided at a rear end portion of the safety rod. The formed screw shaft is screwed together, and a pair of switches for confirming the elevation of the stopper member are provided in the engaging device, and a pair of switches for restricting movement of the safety rod are provided at the screw shaft side rear end of the safety rod. A safety device in a mold clamping device, wherein a switch is provided, and both switches enable automatic adjustment of an engagement position by a drive device.