JPH0767712B2 - Shielding device for injection nozzle in injection molding machine - Google Patents

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 high temperature. Shielding device

[0002]

2. Description of the Related Art FIG. 7 (Japanese Patent Publication No. 2-60723) and FIG. 8 show a device for shielding an injection nozzle in an injection molding machine.
What is shown in (Japanese Patent Publication No. 2-63710) is known. The shielding device of the injection nozzle of FIG. 7 includes a door 20 that covers the front surface (lower surface in FIG. 7) of the injection nozzle 1, a cover 21 that covers the upper surface and the rear surface of the injection nozzle 1, hinged to the fixed platen 2, It is structured such that it is attached so as to be rotatable back and forth at 23 respectively.

Further, the shielding device shown in FIG. 8 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]

The shielding device for the injection nozzle of FIG. 7 is opened with the front surface and the upper surface of the injection nozzle 1 connected to each other when the door 20 and the cover 21 are open. 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 nozzle replacement tool becomes difficult to handle, and the injection nozzle 1 can be replaced easily. There is a problem that it is difficult to do.

In the shielding device shown in FIG. 8, the front plate 24a and the rear plate 24c of the cover 24 are located above the front surface and above the rear surface of the injection nozzle when the cover 24 is erected upright. Since it rises, replacement work of the injection nozzle is more difficult than that of FIG. 7, and the cover 24 must be removed in some cases.

By the way, in such an injection nozzle shielding device, as shown in FIG. 7, 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 that is detachably attached to the base member and covers the upper surface and the rear surface of the injection nozzle; and a cover that is movably provided between the detection position and the retracted position on the base member to detect the closed state of the door at the detection position. The limit switch means and a fixing member provided on the cover for fixing the limit switch means to the detection position when the cover is attached to the base member are provided.

[0009]

When the cover is removed, the limit switch means is free to move between the detection position and the retracted position. Therefore, even if the door is closed, it cannot be detected.
When the cover is fixed at a predetermined position so as to cover the upper surface and the rear surface of the injection nozzle, the limit switch means is fixed at the detection position by the action of the fixing member. Therefore, when the door is closed in this state, the limit switch means detects this.

[0010]

1 to 5 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 by 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 shaft 9 by a pivot 10. The limit switch 9
The dog 5a provided on the door 5 detects that the door 5 is closed by pushing the actuator 9a.
Is horizontally rotatable around the
It is possible to freely move between the detection position pushed by and the retracted position where the actuator 9a is not pushed by the dog 5a. The door 5 covers the front surface of the injection nozzle 1 and has a transparent window 5b at the center thereof.

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 fixing member 13 is provided integrally with the cover 12 on the lower surface of the top plate 12a of the cover 12. The fixing member 13 rotates the limit switch 9 to the retracted position when the cover 12 is laterally moved and fitted to the base member 3.
Is pressed by the tip 13a to rotate it to the detection position, and the limit switch 9 is fixed at that position. The top plate 12a is formed with a notch 12e for pulling out the cable of the limit switch 9.

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
(Not shown in FIG. 3) and also shows a shielding state in which the upper surface and the rear surface of the injection nozzle 1 are covered by the cover 12. In this state, the limit switch 9 is fixed to the detection position by the fixing member 13. ing. Therefore, the limit switch 9 is pushed by the dog 5a of the door 5 in the closed state, and the limit switch 9 outputs a shielding signal for enabling the injection of resin or the like.

When the door 5 is rotated and opened with the hinge 6 as a fulcrum 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. Stay safe. Further, when the fixing screw 7 is loosened from the shielded state and the cover 12 is moved to the right in FIG. 1 and FIG. 2 (front side in FIG. 3) and removed from the base member 3, the fixing member 13 is separated from the limit switch 9, The limit switch 9 extends the operator 9a, which has been compressed by the dog 5a, and rotates the limit switch 9 around the pivot 10 to the retracted position to be turned off.

As can be seen from the above, the door 5
Even if the door is closed, the limit switch 9 is pushed by the dog 5a of the door 5 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. do not do. 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. 6 shows another embodiment of the present invention. In this shielding device, the limit switch 9 is movably provided along the rail 15 between the detection position and the retracted position. The cover and fixing member of this shielding device are the same as those of the shielding device of FIGS.

The limit switch 9 shown in FIGS. 1 to 5 is
Although it is horizontally rotatable, it may be rotatable vertically.

[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. A cover for covering the upper surface and the rear surface of the injection nozzle that is detachably attached to the base member, and a base member that is movable between the detection position and the retracted position to detect the closed state of the door at the detection position. Limit switch means and a fixing member which is provided on the cover and fixes the limit switch means to a detection position when the cover is attached to the base member. Since they can be continuously and completely opened, the injection nozzle can be easily replaced. 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 an external view of a base member and a cover.

FIG. 6 is a plan view showing another mounting example of the limit switch.

FIG. 7 is a plan view of a conventional shielding device.

FIG. 8 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) 12 Cover 13 Fixed Member

Claims (1)

[Claims] 1. A base member attached to a fixed plate,
A door which is rotatably attached to the fixed plate and covers the front surface of the 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 a detection position and a retracted position on the base member. Limit switch means movably provided between the detecting positions to detect the closed state of the door, and a fixing member provided to the cover for fixing the limit switch means to the detecting position when the cover is attached to the base member. A shielding device for an injection nozzle in an injection molding machine, which is characterized by being provided.