JPH0671719A - Shielding device of injection nozzle for injection molding machine - Google Patents

Abstract

PURPOSE:To detect shielding of an injection nozzle by a door and a cover by one limit switch. CONSTITUTION:A base member 3 is mounted at a stationary board 2, and a limit switch 9 and a shielding member 10 are provided at the member 3. When a cover 12 is laterally moved from an injection nozzle 11 toward the board 2 and engaged with the member 3, a stationary member 13 provided at the cover 12 pushes an end 10a of the member 10 to rotate the member 10 upward at a pivotal shaft 11 as a center to retract it from a front surface of an actuator 9a of the limit switch 9. When a door 5 is rotated at a hinge 5 as a center to be closed in this state, a dog 5a pushes an actuator 9a of the switch 9. When the cover 12 is removed, the member 12 is fallen down to shield the front face of the actuator 9a, and even if the actuator 9a is hence pressed by the dog 5a, the switch 9 is not closed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an injection nozzle for a molten resin in a heating cylinder, which is provided in order to protect a worker from scattering of the resin which is generated when a free shot of the molten resin is made and contact with the injection nozzle at a high temperature. Shielding device

[0002]

2. Description of the Related Art FIG. 9 (Japanese Patent Publication No. 2-60723) and FIG. 1 show a device for shielding an injection nozzle in an injection molding machine.
No. 0 (Japanese Patent Publication No. 2-63710) is known. The shielding device for the injection nozzle of FIG.
A door 20 that covers the front surface (the lower surface in FIG. 9) and a cover 21 that covers the upper surface and the rear surface of the injection nozzle 1 are attached to the fixed board 2 by hinges 22 and 23 so as to be rotatable back and forth. Has been done.

Further, the shielding device shown in FIG. 10 has a cover 24 having a U-shaped cross section in which a front plate 24a for covering the front surface of the injection nozzle, a top plate 24b for covering the upper surface, and a rear plate 24c for covering the rear surface are integrally formed. Is fixed to the fixed platen 2 by a hinge 25 so as to be vertically rotatable.

[0004]

In the injection nozzle shielding device of FIG. 9, when the door 20 and the cover 21 are open, the injection nozzle 1 is opened in a state where the front surface and the top surface of the injection nozzle 1 are connected to each other. Cover 2 is above the rear surface of 1
Since the top plate 21a of No. 1 is present and the front surface, the upper surface and the rear surface are not completely opened in the circumferential direction of the injection nozzle 1, the injection nozzle 1 cannot be replaced easily.

Further, in the shielding device of FIG. 10, when the cover 24 is erected upright, the front plate 24a and the rear plate 24c of the cover 24 are located above the front surface of the injection nozzle.
Also, since it rises above the rear surface, replacement work of the injection nozzle is more difficult than that of FIG. 9, and the cover 24 must be removed in some cases.

By the way, in such an injection nozzle shielding device, as shown in FIG. 9, for example, a limit switch 26 for detecting that the door 20 is closed is provided on the fixed board 2 to open the door 20. Although the injection of resin in the state is prevented, the cover 21 is not considered. Therefore, it cannot be said that it is sufficiently safe, and if the cover 21 is also provided with safety measures, two limit switches are required, and the structure including the wiring and the like becomes complicated, which is not economical.

According to the present invention, the replacement work of the injection nozzle can be easily performed, and the shielding state of the injection nozzle by the door and the cover can be detected by one limit switch.
An object of the present invention is to provide a shielding device for an injection nozzle in an injection molding machine.

[0008]

In order to achieve the above object, the present invention relates to a base member mounted on a fixed plate and a door rotatably mounted on the fixed plate to cover the front surface of an injection nozzle. A cover which is detachably attached to the base member and covers the upper surface and the rear surface of the injection nozzle, and limit switch means which is provided on the base member and detects the closed state of the door by pressing the operator with the dog of the door, The base member is provided with a blocking member for blocking the front surface of the operator in a normal state, and a pressing member provided in the cover for retracting the blocking member from the front surface of the operator when the cover is attached to the base member. It was configured.

[0009]

When the cover is removed, the shutoff member shuts off the front face of the operator of the limit switch means. Therefore, the dog of the door is blocked by the blocking member and the operator cannot be pushed, and the limit switch means does not output the detection signal. When the cover covers the upper surface and the rear surface of the injection nozzle and is fixed at a predetermined position, the pressing member retracts the blocking member from the front surface of the operator. Therefore, when the door is closed in this state, the limit switch means pushes the actuator with the dog to detect the blocking state of the injection nozzle.

[0010]

1 to 7 show an embodiment of an injection nozzle shielding device in an injection molding machine according to the present invention. In these figures, reference numeral 1 is an injection nozzle, and 2 is a fixed platen. A base member 3 is attached to the fixed platen 2 with screws 4, and a door 5 is attached to the fixed platen 2 via a base member 3 so as to be rotatable back and forth with a hinge 6. The base member 3 has a fixed seat 3a and a mounting seat 3b. The mounting seat 3b is formed lower than the fixed seat 3a.

A fixing screw 7 is attached to the fixing seat 3a of the base member 3.
Is screwed onto the nut 8 and is provided vertically, and the mounting seat 3b
A limit switch (limit switch means) 9 is attached to the. The limit switch 9 detects that the operator 5a is pushed by the dog 5a provided on the door 5 to close the door 5, and is fixed to the mounting seat 3b. The door 5 covers the front surface of the injection nozzle 1 and has a transparent window 5b at the center thereof.

A blocking member 10 inserted between the end of the base member 3 on the door 5 side and a support piece 3c fixed to the end is attached by a pivot 11 so as to be vertically movable. ing. In a normal state where no force is applied, the blocking member 10 is supported by the bottom side of the support piece 3c and blocks the front surface of the actuator 9a in a substantially horizontal tilted posture. In this cutoff state, the dog 5a cannot push the actuator 9a.

Reference numeral 12 is a cover. Cover 1
2 includes a top plate 12a that covers the upper surface of the injection nozzle 1, a rear plate 12b that covers the rear surface of the injection nozzle 1, and a fitting piece 12c. The cover 12 is horizontally moved from the injection nozzle 1 side toward the fixed platen 2 so that the cover 12 and the fitting piece 1 can be moved horizontally.
It can be fitted to the base member 3 at 2c, and can be laterally moved in the opposite direction to be removed from the base member 3. In the fitted state of the cover 12, a cutout groove 12d is formed at a position corresponding to the nut 8 of the top plate 12a. Fixing screw 7
Is fastened in the cutout groove 12d to fix the cover 12 to the base member 3.

A pressing member 13 is provided integrally with the cover 12 on the lower surface of the top plate 12a of the cover 12. The pressing member 13 pushes the end portion 10a of the blocking member 10 when the cover 12 is laterally moved to be fitted to the base member 3, and is pushed down horizontally as shown by a two-dot chain line in FIG. The blocking member 10 that has blocked the front surface of the above is erected upward as shown by the solid line in FIG. The top plate 12a has a cutout 12e for pulling out the cable of the limit switch 9.
Are formed.

Next, the operation of the injection nozzle shielding device in the injection molding machine of the present invention constructed as described above will be described. 1 to 3, the front surface of the injection nozzle 1 is provided with a door 5
3 shows a shielded state in which the upper surface and the rear surface of the injection nozzle 1 are covered with a cover 12 (not shown in FIG. 3). In this state, the blocking member 10 is pressed by the pressing member 13 to cause the actuator 9a. Is retracted from the front of the. For this reason, the limit switch 9 outputs a shield signal that enables the injection of resin or the like by pressing the actuator 9a by the dog 5a of the door 5 in the closed state.

When the door 5 is opened from the above-mentioned shielded state, the dog 5a is separated from the operator 9a, so that the limit switch 9
Is turned off and the resin cannot be injected, so safety is maintained. Further, after the cover 12 is removed and the injection nozzle 1 is replaced, the cover 5 is forgotten and the door 5
Even if you try to inject the resin by closing only the blocking member 10,
Is lying on the front face of the actuator 9a and the dog 5a
The limit switch 9 will not be turned on and the door 5 will not be closed completely.

As can be seen from the above, the door 5
The limit switch 9 in which the operator 9a is pushed by the dog 5a does not function unless the cover 12 is properly fitted to the base member 3 to cover the upper surface and the rear surface of the injection nozzle 1. Therefore, the limit switch 9 consequently detects the blocking of the injection nozzle 1 by the door 5 and the cover 12 at the same time.

FIG. 8 shows another embodiment of the present invention. The blocking member 15 of this blocking device is movable left and right within the support piece 3d. In the normal state, the blocking member 15 is pushed by the spring 16 to block the front surface of the actuator 9a (see 2 in FIG. 8).
If the cover is attached at a predetermined position, the actuator 9a is pressed by the pressing member 13 as shown by the solid line in FIG.
Evacuate from the front of the. The cover and the like of this shielding device are the same as those of the shielding device shown in FIGS.

[0019]

As described above, the injection nozzle shielding device in the injection molding machine of the present invention includes a base member mounted on a fixed plate and a front surface of the injection nozzle rotatably mounted on the fixed plate. And a cover that is detachably attached to the base member and that covers the upper surface and the rear surface of the injection nozzle, and a limit switch that is provided on the base member and that detects the closed state of the door when the operator is pushed by the dog of the door. Means, a blocking member provided on the base member for blocking the front surface of the operator in a normal state, and a pressing member provided on the cover for retracting the blocking member from the front surface of the operator when the cover is attached to the base member. Since the injection nozzle is configured to include a front surface, an upper surface, and a rear surface of the injection nozzle, the injection nozzle can be completely and easily opened. It is possible to perform the replacement or the like easily. Further, since only one limit switch is required, the whole structure is simpler and economical.

[Brief description of drawings]

FIG. 1 is a front view showing an embodiment of a shielding device for an injection nozzle in an injection molding machine of the present invention.

FIG. 2 is a partially cutaway plan view of the same.

FIG. 3 is a sectional view showing a relationship between a base member and a cover and the like.

FIG. 4 is a plan view of a cover.

FIG. 5 is a sectional view of a portion of a blocking member.

FIG. 6 is a front view showing a relationship between an actuator and a blocking member and the like.

FIG. 7 is a side view of the same.

FIG. 8 is a front view showing another example of the blocking member of the present invention.

FIG. 9 is a plan view of a conventional shielding device.

FIG. 10 is an external view of another conventional shielding device.

[Explanation of symbols]

 1 Injection Nozzle 2 Fixed Plate 3 Base Member 5 Door 9 Limit Switch (Limit Switch Means) 10, 15 Blocking Member 12 Cover 13 Pressing Member

Claims (1)

[Claims] 1. A base member attached to a fixed plate,
A door rotatably attached to the fixed plate to cover the front surface of the injection nozzle, a cover detachably attached to the base member to cover the upper surface and the rear surface of the injection nozzle, and a dog provided on the base member for the door. Limit switch means for pressing the operator to detect the closed state of the door, a blocking member provided on the base member for blocking the front surface of the operator in a normal state, and a cover provided on the cover and attached to the base member. A blocking device for an injection nozzle in an injection molding machine, comprising: a pressing member that retracts the blocking member from the front surface of the operator in a state.