JP2755136B2 - Nozzle device of 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 a nozzle device which is mounted on a heating cylinder of an injection molding machine and injects a resin into a mold.

[0002]

2. Description of the Related Art As a nozzle device of an injection molding machine, FIG.
(Japanese Utility Model Application Laid-Open No. 62-157210)
No.). In the nozzle device, a rod-shaped valve body 3 that abuts against a valve seat 1a of the nozzle 1 and closes an injection port 1b in a measuring step is axially inserted into an axial hole 2a of a cylinder head 2 to which a nozzle 1 is screwed. The shaft hole 2a is slidably inserted.
A resin reservoir Jc is formed between the inner peripheral surface of the valve body 3 and the outer peripheral surface of the valve body 3, and a discharge hole 2b having only one end opened to the outside.
Is provided in communication with the resin reservoir Jc.

In the injection process, the valve element 3 of the nozzle device receives the pressure of the resin in the pressure receiving portion 3a and retreats to the right in the drawing, and opens the injection port 1b. In the weighing process,
The lever 5 rotated by the operating shaft 4 is pushed to the left in the figure to come into contact with the valve seat 1a and close the injection port 1b.
Reference numeral 6 denotes a heating cylinder to which the cylinder head 2 is attached, and 2c denotes a resin passage formed in the cylinder head 2.

[0004]

In the above-described nozzle device, the resin in the nozzle 1 gradually enters the resin reservoir Jc by the pressure applied in the injection or metering step and the movement of the valve body 3. It leaks out through the discharge hole 2b. The resin reservoir Jc only temporarily stores the resin, and when the resin reservoir Jc becomes full and the resin starts to leak out of the discharge hole 2b, the resin reservoir Jc comes out slightly but continuously. For this reason, the exposed resin must be constantly wiped at short time intervals, and if neglected, there is a problem that the surroundings are soiled.

[0005] It is an object of the present invention to provide a nozzle device of an injection molding machine capable of removing resin by periodic cleaning at relatively long time intervals.

[0006]

In order to achieve the above object, a nozzle device of an injection molding machine according to the present invention is provided with a valve seat of the nozzle in a shaft hole of a cylinder head to which the nozzle is attached in a measuring step. A valve body for closing an injection port by abutment with a nozzle is slidably inserted in the axial direction, and a resin reservoir is formed between an inner peripheral surface of the shaft hole and an outer peripheral surface of the valve body. The apparatus has a configuration in which cleaning holes whose both ends are freely opened to the outside are provided directly or indirectly in communication with the resin reservoir.

The cleaning hole can be provided in the cylinder head, or provided in a movable member which is moved by the moving means to bring the valve body into contact with the valve seat, and is provided with a resin reservoir through a communication hole formed in the valve body. Can also be communicated with. The cleaning hole is preferably formed in a straight line.

The cleaning hole is provided with a detector for detecting that a predetermined amount of resin has flowed into the cleaning hole, and a force is applied to the resin flowing into the cleaning hole from one opening end to allow the resin to flow from the other opening end to the outside. It is preferable to provide a cleaning means for causing the water to flow out.

[0009]

When the resin fills the resin reservoir, the resin flows into the cleaning hole from the resin reservoir. Both ends of the cleaning hole can be opened to the outside, so if an appropriate amount of resin accumulates in the cleaning hole,
A force can be applied to the resin of the cleaning hole from one opening end of the cleaning hole by the cleaning means, and the resin can flow out of the other opening end to the outside. Because this operation empties the inside of the cleaning hole, there is no need to clean again until an appropriate amount of resin accumulates in the cleaning hole.
It does not take time and effort.

[0010]

1 to 3 show an embodiment of a nozzle device of an injection molding machine according to the present invention. Note that the same members as those in FIG. 10 are denoted by the same reference numerals, and description thereof will be omitted. The resin reservoir J of the nozzle device of this embodiment includes an annular groove 3b formed on the outer peripheral surface of the valve body 3 and an annular groove 2d formed on the inner peripheral surface of the shaft hole 2a. A cleaning hole 2f communicates with the resin reservoir J through a communication hole 2e. Both the communication hole 2e and the cleaning hole 2f are formed in the cylinder head 2, and the communication hole 2e crosses the upper and lower intermediate portions of the cleaning hole 2f at right angles. The cleaning hole 2f is formed in a linear shape, and its upper and lower ends P1 and P2 are opened to the outside. The cross-sectional shape of the cleaning hole 2f is circular. The end of the communication hole 2 e is closed by a stopper 8.

A through hole 2g is formed in the center of the cylinder head 2. The shaft hole 2a opens to the through hole 2g, and the valve body 3
Has one end protruding through the through hole 2g. A spring receiver (movable member) 9 is inserted into the through hole 2g, and is urged to the left in FIG. 1 by a coil spring (moving means) 10 to push the valve body 3. A cleaning rod (cleaning means) 11 is attached to the cleaning hole 2f. The cleaning rod 11 is inserted into the cleaning hole 2f from one opening end P1 and removes the resin in the cleaning hole 2f from the other opening end P1.
2 to forcibly discharge it to the outside. The cleaning hole 2f can be formed horizontally or diagonally. In this way, even if the resin has low viscosity, it will not flow out of the cleaning hole 2f without permission.

Next, the operation of the nozzle device of the injection molding machine according to the present invention having the above configuration will be described. When the resin in the heating cylinder 6 enters the nozzle 1 through the plurality of passages 2c (only one is shown in FIG. 1) in the injection process,
The valve body 3 receives the resin pressure at the pressure receiving portion 3a and retreats rightward in FIG. 1 to open the injection port 1b. When the injection is completed, the valve body 3 is pushed by the coil spring 10 via the spring receiver 9 to close the injection port 1b. A portion of the resin pressurized in the injection step temporarily accumulates in the resin sump J through the gap between the shaft hole 2a and the valve body 3 as before, and gradually exits to the cleaning hole 2f as time passes. The resin that has come out of the cleaning hole 2f accumulates in the cleaning hole 2f due to its own viscosity.

When a proper amount of resin has accumulated in the cleaning hole 2f, the cleaning rod 11 is moved from one opening end P1 to the cleaning hole 2f.
, The resin is pushed by the cleaning rod 11 and discharged out of the other open end P2. The inserted cleaning rod 11 is pulled out from the cleaning hole 2f. With the above operation, the cleaning hole 2f
Is empty, so that it is not necessary to take time and effort to clean the resin until the proper amount of resin accumulates in the cleaning hole 2f again, and the surroundings are not contaminated by the resin.

FIG. 4 shows a second embodiment of the present invention. In this nozzle device, the cleaning hole 2f communicates directly with the resin reservoir J. Other configurations and operations are the same as those of the first embodiment shown in FIGS. In the second embodiment, it is not necessary to provide the communication hole 2e (FIG. 2), but the resin passage 2c is shifted to one side (the left in FIG. 4) of the cylinder head 2.

FIGS. 5 and 6 show a third embodiment of the present invention. In this nozzle device, the resin reservoir Ja is an extension of the communication hole 2h. In this embodiment, it is preferable that the diameter of the resin reservoir Ja (communication hole 2h) is sufficiently larger than the diameter of the valve body 3 as shown in the figure, but the diameter of the resin reservoir Ja is set to be equal to or less than the diameter of the valve body 3. It is not impossible to do it. Other configurations and operations are the same as those of the first embodiment in this case.

FIGS. 7 and 8 show a fourth embodiment of the present invention. In this nozzle device, the communication hole 3
c, 3d are formed, and a cleaning hole 9a, a communication hole 9b, and a fitting hole 9c are formed in the spring receiver 9. The valve body 3 is fitted in the fitting hole 9c, and the cleaning hole 9a is
It communicates with the resin reservoir Jb via b, 3d, 3c. The valve body 3 is not provided with the annular groove 3b (FIG. 2), and the resin reservoir Jb is formed only by the annular groove 2d of the cylinder head 2.

In the case of this nozzle device, the resin in the resin reservoir Jb flows out to the cleaning hole 9a through the communication holes 3c, 3d, 9b. Other configurations and operations are the same as those of the first embodiment, but since there is no need to provide a cleaning hole in the cylinder head 2, restrictions on forming the resin passage 2c are reduced.
There is an advantage that the distance between the passages 2c, 2c can be increased, and the resin can be evenly distributed to the left and right (or up and down) without offset.

In each of the above embodiments, the cleaning holes 2f, 9
For example, a detector 13 as shown in FIG. 9 can be attached to a. The detector 13 is configured such that the plugs 14 and 15 detachably screwed to the opening ends P1 and P2 of the cleaning holes 2f and 9a, and the rod 16a are inserted through the holes 14a of the plug 14 to form the cleaning holes 2a and 9b.
f, 9a, a display member 17 screwed to the outer end of a rod 16a, and a plug 1
4 and a spring 18 inserted between the piston 16 and biasing the piston 16 downward.

The operation of the detector 13 will be described. When resin flows into the cleaning holes 2f and 9a from the state shown by the solid line in FIG. 9 and reaches a predetermined amount, the piston 16 is pushed by the resin and rises, and the display member 17 is raised. Is floated like a two-dot chain line. Therefore, the amount of resin in the cleaning holes is known from the flying height of the display member 17, and the resin in the cleaning holes 2f and 9a can be removed in a timely manner. Needless to say, the resin is removed by removing the stoppers 14 and 15. The spring 18 can be omitted.

The resin reservoirs J and Jb can be formed in both or one of the annular grooves 2d and 3b.
Further, as the cleaning means, in addition to the cleaning rod 11 of FIG. 3, blowing of resin by compressed air or suction by vacuum action can be used. When the cleaning means is configured as described above or when the flexible cleaning rod 11 is used, the cleaning holes 2f, 9a
Need not necessarily be linear. Further, the detector 13
The structure and type of are arbitrary.
A configuration in which the amount of resin is electrically detected may be employed. Further, the driving device of the valve body is optional, and can be moved by the lever 5 as shown in FIG. 10, for example. The shaft hole 2a may not be formed directly in the cylinder head 2 but may be formed by fitting another member such as a pipe to the cylinder head 2.

[0021]

As described above, in the nozzle device of the injection molding machine according to the present invention, the injection port is brought into contact with the shaft hole of the cylinder head to which the nozzle is attached by abutting the valve seat of the nozzle in the measuring step. In a nozzle device of an injection molding machine, a closing valve element is slidably inserted in an axial direction, and a resin reservoir is formed between an inner peripheral surface of the shaft hole and an outer peripheral surface of the valve element.
Since the cleaning holes, both ends of which can be freely opened to the outside, are configured to be provided directly or indirectly in communication with the resin reservoir, when an appropriate amount of resin is accumulated in the cleaning holes,
A force can be applied to the resin from one opening end of the cleaning hole by a suitable cleaning means such as a cleaning stick, and the resin can be discharged to the outside from the other opening end. Therefore, it is not necessary to take time for cleaning until an appropriate amount of resin is accumulated in the cleaning hole again. The surroundings are not stained by the resin.

The cleaning hole can be provided in a movable member such as a spring receiver, but in this case, it is not necessary to provide the cleaning hole in the cylinder head where the resin passage is formed.
Restrictions in forming the resin passage are relaxed, and the distance between the adjacent passages can be increased, and the resin can be distributed left and right or up and down evenly without offsetting the passage.

When the detector is provided, the amount of resin accumulated in the cleaning hole can be easily and accurately known, so that the resin can be discharged from the cleaning hole at an optimum time. Can be cleaned.

[Brief description of the drawings]

FIG. 1 is a sectional view showing one embodiment of a nozzle device of an injection molding machine according to the present invention.

FIG. 2 is a sectional view taken along the line II-II in FIG.

FIG. 3 is an external view illustrating an example of a cleaning stick.

FIG. 4 is a sectional view of a cylinder head and a valve body showing another embodiment of the present invention.

FIG. 5 is a sectional view of a cylinder head and a valve body showing another embodiment of the present invention.

FIG. 6 is a cross-sectional view showing a relationship between the valve body of FIG. 5 and a resin reservoir.

FIG. 7 is a sectional view showing still another embodiment of the present invention.

FIG. 8 is a sectional view of a VIII-VIII portion.

FIG. 9 is a cross-sectional view illustrating an example of a detector.

FIG. 10 is a sectional view of a conventional nozzle device.

[Explanation of symbols]

 1 Nozzle 1a Valve seat 1b Injection port 2 Cylinder head 2a Shaft hole 2e Communication hole 2f Cleaning hole 2h Communication hole 3 Valve 3c Communication hole 3d Communication hole 9 Spring receiver (movable member) 9a Cleaning hole 9b Communication hole 10 Coil spring Means) 11 Cleaning stick (cleaning means) 13 Detector P1 End (open end) P2 End (open end) J Resin pool Ja Resin pool Jb Resin pool

Claims (6)

(57) [Claims] 1. A valve body, which abuts a valve seat of the nozzle in a measuring step and closes an injection port, is slidably inserted in an axial direction into an axial hole of a cylinder head to which the nozzle is attached, and the axial hole is slidably inserted. In a nozzle device of an injection molding machine in which a resin reservoir is formed between an inner peripheral surface of a valve body and an outer peripheral surface of a valve body, a cleaning hole whose both ends are freely openable to the outside is directly or indirectly formed in the resin reservoir. A nozzle device for an injection molding machine, provided in communication with a nozzle. 2. The nozzle device for an injection molding machine according to claim 1, wherein the cleaning hole is provided in the cylinder head. 3. The cleaning hole is provided on a movable member which is moved by the moving means to bring the valve body into contact with the valve seat, and is communicated with the resin reservoir through a communication hole formed in the valve body. The nozzle device for an injection molding machine according to claim 1, wherein 4. The nozzle device for an injection molding machine according to claim 1, wherein the cleaning hole is formed in a straight line. 5. An injection molding machine according to claim 1, wherein said cleaning hole is provided with a detector for detecting that a predetermined amount of resin has flowed into said cleaning hole. Nozzle device. 6. A cleaning means for applying a force to the resin flowing into the cleaning hole from one opening end and causing the resin to flow out of the other opening end to the outside.
Or a nozzle device for an injection molding machine according to 5.