JPH066320B2 - Safety equipment for injection molding machines - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mechanical safety device for an injection molding machine, which keeps safety by preventing mold clamping movement of a movable plate when a safety door is open. The following are conventionally known as mechanical safety devices for injection molding machines. That is, in the safety device of FIGS. 11 and 12, the safety bar 31 having a screw structure is attached to the movable platen 4 by the nut 32.
The stopper 33 to the fixed platen 2 with the pin 3
A safety door (not shown) provided so as to be rotatable up and down by 4 and movable in the moving direction of the movable platen 4 in front of the movable platen 4.
When the safety door 31 is open, the stopper 33 blocks the moving surface of the safety bar 31 to prevent the movable platen 4 from being clamped, and when the safety door is closed, the stopper 33 causes the roller 3 to move.
5 is pushed by the cam (not shown) of the safety door,
As shown by the two-dot chain line in FIG. 2, the safety bar 31 is pivoted upward from the moving surface so that the movable platen 4 can be freely clamped. Reference numeral 25 is a tie rod and 36 is a cover.

The safety device shown in FIGS. 13 and 14 has a safety bar 4 having a plurality of fixed teeth 41a formed at predetermined intervals in the axial direction.
One end of the safety bar 41 is fixed to the movable plate 4, the other end of the safety bar 41 is inserted into the insertion hole 3a formed in the end plate 3, and the fixed tooth 41a of the safety bar 41 is locked to the end plate 3. A stopper 42 for blocking the mold clamping movement of the movable platen 4 via a safety bar 41 is attached by a pin 43 so as to be vertically rotatable, while a lever 44 is attached to the machine body 1.
A rotating rod 45 provided with is provided so as to be vertically rotatable and parallel to the safety bar 41, and when the safety door 5 is open,
The stopper 42 locks the fixed teeth 41a of the safety bar 41 to prevent the movable platen 4 from being clamped by the toggle type clamping device 26, and when the safety door 5 is closed, a cam provided on the safety door 5 is provided. The roller 47 of the lever 44 is pushed by 46 to rotate the rotating rod 45, and the roller 48 of the stopper 42 is rotated.
Is pressed to remove the stopper 42 from the fixed tooth 41a so that the movable platen 4 can be freely clamped.
-115523 publication). In FIGS. 13 and 14, reference numeral 2 is a fixed platen and 27 is a mold.

[Problems to be Solved by the Invention]

The safety device of FIGS. 11 and 12 is troublesome because it is necessary to loosen the nut 32 and adjust the protruding length of the safety bar 31 when the thickness of the mold or the amount of mold opening stroke is changed. There is a point.

Further, the safety device shown in FIGS. 13 and 14 has a stopper 42.
A long rotating rod 45 for operating the machine body 1
Since the safety bar 41 is fixed to the movable platen 4 and moves together with the movable platen 4, the inertia of the movable platen 4 is increased by that much and the operability is reduced. There is a problem.

The present invention provides a safety device for an injection molding machine, which does not require adjustment even if the thickness of the mold is changed, does not increase the inertia of the movable plate, operates smoothly, and has a simple structure. To aim.

[Means for Solving the Problems]

In order to achieve the above-mentioned object, according to the present invention, a safety door that covers a portion of a mold is movable in front of a movable plate which is moved by a mold clamping device and clamps a mold with a fixed plate. In the injection molding machine installed in, the safety bar with a plurality of fixed teeth formed at predetermined intervals in the axial direction is rotated in the circumferential direction near the safety door with the axial direction aligned with the moving direction of the movable plate. Freely provided, the movable plate is provided with a stopper that locks to the fixed teeth of the safety plate to prevent the movable platen from being clamped, and the safety door and the safety bar are provided at the final stage of the closing movement of the safety door. Rotate the safety bar in the circumferential direction to retract the fixed teeth from the stopper locking position when the safety door is closed, and rotate the safety bar in the circumferential direction when the safety door is opened to stop the safety bar. The rotation means for attaching the fixed teeth is additionally provided at the locking position.

[Action]

When the safety door in the closed state is opened, the rotating means acts to rotate the safety bar in the circumferential direction, and the fixed tooth is attached to the stopper locking position to lock the fixed tooth on the stopper. Therefore, in the unlikely event that the mold clamping device operates as a mold clamp,
The movable plate does not move in the mold clamping, and safety is maintained.

When the safety door in the open state is closed, the rotation means acts to rotate the safety bar in the circumferential direction, retract the fixed tooth from the locking position of the stopper, and remove it from the stopper. Therefore, when the safety door is closed, the movable platen is normally moved by the mold clamping device to perform mold clamping and mold opening.

The safety bar has a plurality of fixed teeth, and one fixed tooth corresponding to the amount of mold opening stroke of the movable plate is locked to the stopper, so adjustment is possible even if the thickness of the mold changes. It is unnecessary.

Also, the safety bar does not move with the movable plate,
Since the safety door is configured to rotate in the circumferential direction on the spot by the movement of the safety door, there is no fear that the inertia of the movable plate is increased and the operability is impaired.

〔Example〕

1 to 6 show an embodiment of the present invention.
Reference numeral 1 in the drawing is a machine body of the injection molding machine. A fixed platen 2 is fixed to the machine body 1, and an end plate 3 is attached to the fixed platen 2 via a tie rod (not shown). A movable platen 4 is arranged between the fixed platen 2 and the end plate 3 and is slidably supported by the tie rods. The movable platen 4 is moved to the right in FIG. 1 by a toggle type mold clamping device (not shown) to clamp the mold. A safety door 5 is provided in front of the movable platen 4 (front side in FIG. 1) so as to be movable in the moving direction of the movable platen 4. The structure of the injection molding machine is well known.

Bearings 6, 7 are bolts 8 on the machine body 1 and the fixed platen 2.
Blocks 9 and 9 each having an insertion hole 9a are attached to the movable platen 4. A safety bar 10 having a substantially circular cross section is inserted through the through holes 9a, 9a of the blocks 9, 9, and both ends of the safety bar 10 are axially supported by bearings 6, 7 so as to be rotatable in the circumferential direction. The safety bar 10 has its axial direction aligned with the moving directions of the movable platen 4 and the safety door 5.

A plurality of fixed teeth 10a are provided on one surface of the safety bar 10 at predetermined intervals in the axial direction of the safety bar 10, and a side surface 90 degrees out of phase with the surface on which the fixed teeth 10a are formed is It is a plane 10b. The safety bar 10 locks the fixed tooth 10a to the stopper 11 to prevent the movable platen 4 from being clamped. The stopper 11 is formed in an L shape, and is attached between the blocks 9 and 9 by a pin 12 so as to be vertically rotatable. The fixed tooth 10a is formed in a sawtooth shape and has a vertical surface 10c and an inclined surface 10d. Slope 1
0d is formed so as to gradually increase from the fixed platen 2 toward the movable platen 4. Therefore, in the above configuration, the mold clamping movement of the movable platen 4 to the right in FIG. 1 is prevented by the stopper 11 engaging with the vertical surface 10c of the fixed tooth 10a. When the mold is opened to the left in the figure, the stopper 11 moves the inclined surface 10d.
The movable platen 4 can be freely moved because the pin 12 is rotated upward by sliding on the pin 12.

A lever 13 is attached to the safety bar 10 so as to project in the radial direction of the safety bar 10. The lever 13 has a roller 14 at its tip. A cam 15 is attached to the end plate 3 side of the safety door 5. The cam 15 is inclined so as to become higher as it approaches the end plate 3 from the fixed platen 2, and is arranged at a position crossing the vertical rotation surface of the roller 14 which rotates vertically together with the lever 13. .

When the safety door 5 is moved toward the end plate 3 and opened, the cam 15 separates from the roller 14 of the lever 13 and frees the safety bar 10 from rotating clockwise in FIG. As a result, the safety bar 10 pivots the fixed tooth 10a upward to attach it to the locking position of the stopper 11. Also, the cam 15
Touches the roller 14 at the final stage of the closing movement of the safety door 5 and gradually raises it to rotate the safety bar 10 in the circumferential direction via the lever 13 and fix the safety door 5 in the closed state. The tooth 10a is retracted from the locking position of the stopper 11. Lever 13, roller 14, and cam 1
Reference numeral 5 constitutes a rotating means 16 of the safety bar 10.

A weight 17 and a locking piece 18 are attached to the safety bar 10. The weight 17 includes the lever 13 and the roller 1.
The rotation torque of the safety bar 10 in the circumferential direction is applied in cooperation with the safety bar 10 to ensure the rotation of the safety bar 10 when the safety door 5 is opened. The locking piece 18 abuts a fixture 19 provided on the bearing 6 to prevent the safety bar 10 from excessively rotating, and stops the roller 14 at a predetermined lowered position. 20 is a safety door 5
It is a guide rail.

Next, the operation of the safety device of the injection molding machine according to the present invention configured as described above will be described.

FIG. 1 shows a state in which the safety door 5 is opened.
The safety bar 10 has the fixed teeth 10a pivoted upward by the action of the weight 17 and the like so as to be positioned at the locking position of the stopper 11, and the stopper 11 is locked to the fixed teeth 10a. Therefore, even if the mold clamping device performs the mold clamping operation, the movable platen 4 does not move due to the mold clamping and no danger occurs.

When the safety door 5 in the opened state is closed, the safety bar 10 is rotated clockwise by the action of the cam 15 via the roller 14 and the lever 13 to be in the state shown by the solid lines in FIGS. The tooth 10a is retracted from the locking position of the stopper 11 and the plane 10b of the safety bar 10 is positioned above. At this time, there is a gap between the flat surface 10b and the end surface of the stopper 11, so that the mold clamping movement of the movable platen 4 can be normally performed.

FIG. 7 shows a second embodiment of the present invention. In this embodiment, the safety bar 10 is rotatably supported by bearings 6 and 21 fixed to the machine body 1. Since the structure other than this is the same as that of the first embodiment, the same reference numerals are given and the detailed description thereof is omitted.

8 to 10 show a third embodiment of the present invention. This embodiment is an example of an injection molding machine having a vertical mold clamping mechanism in which the movable platen 4 moves in the vertical direction.

The spring 50 pulls the stopper 11 to ensure that it engages with the fixed tooth 10a of the safety bar 10. The other spring 51 applies a rotational torque in the circumferential direction to the safety bar 10 to prevent the safety bar 10 from moving when the safety door 5 is opened.
Ensure the rotation of. The cam 15 moves away from the roller 14 of the lever 13 when the safety door 5 moves in the direction perpendicular to the paper surface in FIG. 8 (upward in FIG. 10) and is opened, and moves in the clockwise direction in FIG. 10 of the safety bar 10. Free to rotate. Further, the cam 15 is provided on the roller 1 at the final stage of the closing movement of the safety door 5.
4, the safety bar 10 is rotated in the circumferential direction via the lever 13, and the fixed tooth 10a is retracted from the locking position of the stopper 11 when the safety door 5 is closed. Since the structure of this embodiment is the same as that of the first embodiment except for the above, the same reference numerals are given and detailed description thereof is omitted.

〔The invention's effect〕

As described above, the safety device of the injection molding machine according to the present invention covers the mold part before the movable platen that is moved by the mold clamping device and clamps the mold with the fixed platen. In an injection molding machine in which a safety door is movably installed, a safety bar that has a plurality of fixed teeth formed at predetermined intervals in the axial direction is located near the safety door so that the axial direction matches the moving direction of the movable plate. It is provided so as to be rotatable in the circumferential direction, and the movable plate is provided with a stopper that locks the fixed teeth of the safety bar to prevent the mold clamping movement of the movable plate. At the final stage of the door closing movement, the safety bar is rotated in the circumferential direction to retract the fixed teeth from the stopper locking position when the safety door is closed, and the safety bar is opened when the safety door is opened. A rotating hand that rotates in the circumferential direction and attaches fixed teeth to the stopper locking position. Since There has been a attached configurations, it is possible to cope with this without any adjustment even when the thickness of the mold is changed. Further, since the safety bar does not move together with the movable plate and only rotates in the circumferential direction by opening / closing the safety door, the operability of the movable plate is not impaired. Moreover, since the member such as the long rotating rod of the conventional safety device is not required, the structure is simple.

[Brief description of drawings]

1 to 6 show a first embodiment of the present invention. FIG. 1 is a partially cutaway front view showing the relationship between a movable platen and a safety bar, and FIG. II-II) arrow view, FIG. 3 is a (III-III) arrow view of FIG. 1 in a state where the fixed tooth is retracted from the stopper locking position, and FIG. 4 is a view of FIG. 1 (IV-
IV) View from the arrow, FIG. 5 is a cross-sectional view showing the relationship between the roller and the cam, and FIG. 6 is a front view of the same. FIG. 7 shows the second aspect of the present invention.
1 is a schematic front view of a main part showing an embodiment. 8 to 10 show an embodiment in which the present invention is applied to a vertical injection molding machine. FIG. 8 is a front view of a main part, and FIG. 9 is a front view of FIG.
IX) arrow view, FIG. 10 is the same (XX) arrow view.
11 and 12 show a conventional safety device. FIG. 11 is a front view of a main part, and FIG. 12 is a side view of the same.
13 and 14 show another conventional safety device. FIG. 13 is a partially cutaway front view, and FIG. 14 is a sectional view showing the relationship between a safety bar, a stopper, a rotating rod and the like. Is. 2 ... Fixed plate 4 ... Movable plate 5 ... Safety door 10 ... Safety bar 10a ... Fixed tooth 11 ... Stopper 16 ... Rotation means

Claims (1)

[Claims] 1. An injection molding machine in which a safety door for covering a mold part is movably provided in front of a movable platen which is moved by a mold clamping device and clamps a mold with a fixed platen. A safety bar having a plurality of fixed teeth formed at predetermined intervals in the axial direction is provided near the safety door so as to be rotatable in the circumferential direction with the axial direction aligned with the moving direction of the movable plate. Is equipped with a stopper that locks the fixed teeth of the safety bar to prevent the movable platen from being clamped, and the safety door and safety bar above the safety bar in the circumferential direction at the final stage of the closing movement of the safety door. When the safety door is closed, the fixed teeth are retracted from the stopper locking position, and when the safety door is opened from the closed position, the safety bar is rotated in the circumferential direction to the stopper locking position. The injection molding machine is characterized by being equipped with rotating means for attaching fixed teeth. Apparatus.