JPH07156202A - Nozzle device for injection molding machine - Google Patents

Abstract

PURPOSE:To eliminate a moment so as to smooth an operation and make an injection device near a nozzle so as to reduce a remaining quantity of resin. CONSTITUTION:When an injection device 2 is to be operated, a nozzle 11 is retracted by a drive cylinder 13 so as to open a nozzle 1. When an injection device 12 is to be operated, a nozzle 21 is retracted by a drive cylinder 23. In the case of an injection device 22, a needle 31 is retracted by a drive cylinder 33. As the center axis lines of the nozzles, the needle, and the drive cylinders are nearly conformed, a moment does not work. As it is not necessary to enlarge the diameters of the drive cylinders and the injection device can near the nozzle, a remaining quantity of resin is reduced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a nozzle device of an injection molding machine, which can perform sandwich molding by simultaneously or separately injecting two or more kinds of resins having different kinds and colors into one mold. Regarding

[0002]

2. Description of the Related Art As a nozzle device of a sandwich injection molding machine, as shown in FIGS. 5 and 6, an outer nozzle 1 having an injection port 1a at the front end (the left side in the drawing is the front) is ejected to the front end. An inner nozzle 11 having an outlet 11a and being in contact with the valve seat 1b of the outer nozzle 1 to close the outer nozzle 1 connects the first flow chamber C1 communicating with the first injection device 2 to the outer nozzle 1
A needle 31 which is formed between the inner nozzle 11 and the outer nozzle 1 so as to be concentric with the outer nozzle 1 and axially movable, and which is in contact with the valve seat 11b of the inner nozzle 11 to close the inner nozzle 11. Of the second injection device 12
A flow chamber C11 is formed between the inner chamber 11 and the inner chamber 11, and is inserted concentrically with the inner nozzle 11 so as to be movable in the axial direction.

The inner nozzle 11 is provided with a first drive cylinder 13 for axially moving the inner nozzle 11 with respect to the outer nozzle 1, and the needle 31 is also provided.
Is equipped with a second drive cylinder 33 that moves the needle 31 axially with respect to the inner nozzle 11 (the nozzle device in FIG.
No. 811, see the nozzle device of FIG.
813).

The first drive cylinder 13 in the nozzle device of FIG. 5 is provided with its cylinder body 13a directly connected to the rear end of the outer nozzle 1 and the piston rod 13b directly connected to the rear end of the inner nozzle 11. Further, the second drive cylinder 33 has its cylinder body 33a formed at the rear end of the inner nozzle 11, and has its piston rod 33b attached to the needle 3.
It is directly connected to the rear end of the unit 1. The first injection device 2 communicates with the first flow chamber C1 through the flow hole 1c formed in the outer nozzle 1 and the groove 11c formed in the inner nozzle 11, and the second injection device 12 has the nozzle Flow holes 1d, 11d and needles 3 formed in 1, 11
The second flow chamber C1 through the groove 31d formed in
It has a structure communicating with 1.

On the other hand, in the first drive cylinder 13 in the nozzle apparatus of FIG. 6, its cylinder body 13a is attached to the body 50 of the injection molding machine, and the piston rod 13b is attached to the body 5.
It is connected to the upper slide plate 51. The second drive cylinder 33 has a cylinder body 33a.
Is attached to the slide plate 51, and the piston rod 33b is connected to the rear end of the needle 31. In the case of this nozzle device, the first injection device 2 communicates with the first flow chamber C1 via the flow hole 1c formed in the outer nozzle 1, and the second injection device 12 uses the nozzles 1, 1
It is structured such that it communicates with the second circulation chamber C11 via the circulation holes 1d and 11d formed in the first chamber.

Both the nozzle device shown in FIG. 5 and the nozzle device shown in FIG.
When the injection device 2 is operated to inject the resin, the inner nozzle 11 is retracted by the first drive cylinder 13 to separate the inner nozzle 11 from the valve seat 1b of the outer nozzle 1,
This is performed by opening the injection port 1a of the outer nozzle 1 as shown in FIGS.

When the resin is injected by the operation of the second injection device 12, the inner nozzle 11 is driven by the first drive cylinder 13.
The valve seat 1b of the outer nozzle 1 to close the outer nozzle 1 and the needle 31 is retracted by the second drive cylinder 33 to move the valve seat 11b of the inner nozzle 11 (the nozzle device of FIG. 6). In this case, the inner surface of the injection port 11 is a valve seat.) To the needle 31
And the injection port 11a of the inner nozzle 11 is opened.

[0008]

The nozzle device shown in FIG.
Since the second drive cylinder 33 that drives the needle 31 is built in the inner nozzle 11, it is not convenient to see the operation state of the second drive cylinder 33 from the outside and the operation cannot be easily confirmed. is there. It is not impossible to confirm the operating state of the second drive cylinder 33 by providing a limit switch or the like, but since the second drive cylinder 33 is built in the inner nozzle 11 as described above, Becomes very complicated.

Further, since the rear end portion of the inner nozzle 11, that is, the piston rod 13b of the first drive cylinder 13 becomes thick due to the built-in second drive cylinder 33, the diameter of the first drive cylinder 13 inevitably becomes large. However, there is a problem that the size of the entire apparatus becomes large and the length of the resin passage from each of the injection devices 2 and 12 to each of the flow chambers C1 and C11 becomes long, and the amount of resin remaining therein increases.

In the case of the nozzle device of FIG. 6, although there is no problem as described above, the first drive cylinder 13 pushes and pulls the end of the inner nozzle 11 away from the center axis by the slide plate 51. With this structure, a moment FL (F is a driving force of the drive cylinder 13) is generated in the inner nozzle 11 when the inner nozzle 11 is driven, and smooth operation of the inner nozzle 11 is impaired. Therefore, it is necessary to sufficiently increase the rigidity of the members related to the driving of the inner nozzle 11, and it is necessary to always maintain the accuracy of the sliding parts such as the main body 50 of the injection molding machine and the slide plate 51. Also, there is a problem that management is troublesome.

According to the present invention, the operating state of the drive cylinder can be visually inspected, the entire device can be made small to reduce the amount of residual resin, and the moment is not applied to the nozzle or the like. An object of the present invention is to provide a nozzle device of an injection molding machine that operates smoothly.

[0012]

In order to achieve the above object, the present invention provides an outer nozzle having an injection port at a front end, and an outer nozzle which has an injection port at a front end and is in contact with a valve seat of the outer nozzle. An inner nozzle that closes the nozzle forms a first flow chamber that communicates with the first injection device with the outer nozzle, and is inserted concentrically with the outer nozzle and movably in the axial direction. A needle which contacts the valve seat of the inner nozzle and closes the inner nozzle forms a second flow chamber communicating with the second injection device between the inner nozzle and the needle, and moves concentrically and axially with the inner nozzle. While being freely inserted, the inner nozzle is provided with a first drive cylinder for moving the inner nozzle in the axial direction with respect to the outer nozzle, and the needle is provided in the inner nozzle in the axial direction. Move to In the nozzle device of the injection molding machine provided with the second driving cylinder, the first driving cylinder has its cylinder body substantially at the rear end of the outer nozzle with the center axis of the cylinder body substantially aligned with the center axis of the outer nozzle. A first piston rod whose central axis is substantially aligned with the central axis of the inner nozzle, is connected to the rear end of the inner nozzle, and the second drive cylinder has its cylinder body The second piston rod of the first drive cylinder is provided with a second central axis of the cylinder body.
A piston rod is formed on the first piston rod, the second piston rod and the piston of the first drive cylinder, the piston rod being fixed substantially in line with the central axis of the piston rod and having the central axis substantially aligned with the central axis of the needle. It is configured to be inserted into the shaft hole and connected to the rear end of the needle.

In the nozzle device of the injection molding machine of the present invention, the needle can be formed in the nozzle. It is preferable to provide the second drive cylinder with a second piston rod. Further, between the cylinder body of the drive cylinder and the second piston rod of the drive cylinder, the axial movement of the second piston rod with respect to the cylinder body is detected.
A detection means including a limit switch or the like can be provided.

[0014]

In the first drive cylinder, the center axes of the cylinder body and the piston rod are substantially aligned with the center axes of the concentric outer nozzle and the inner nozzle, and the second drive cylinder is in the cylinder body and the piston. Since the central axis of the rod is substantially aligned with the central axis of the inner nozzle and the needle that are concentric in the same manner as described above, no moment acts when the inner nozzle and the needle are driven. The operating state of the first drive cylinder can be visually confirmed from the moving position of the cylinder body of the second drive cylinder.

Further, since the second drive cylinder is constructed such that its cylinder body is fixed to the second piston rod of the first drive cylinder, the second drive cylinder is the first drive cylinder.
Unlike the conventional nozzle device built in the piston rod of the drive cylinder, the diameter of the first drive cylinder can be reduced. Therefore, each injection device can be brought close to the outer nozzle to reduce the size of the entire device, and the resin passage can be shortened to reduce the amount of residual resin.

When the needle is formed on the nozzle, the number of facilities of the injection device can be increased and the kinds of injection resin can be increased. When the second piston rod is provided in the second drive cylinder, the operating state of the second drive cylinder can be known from the movement of the piston rod. Further, when a detection means such as a limit switch is provided, automatic control or the like becomes possible.

[0017]

1 to 4 show an embodiment of a nozzle device of an injection molding machine according to the present invention. The embodiment shows a nozzle device that can handle three types of resins, but if one component is removed from this device, it will be two types. Members and the like having the same functions as those of the nozzle device of FIGS. 5 and 6 are designated by the same reference numerals, and detailed description thereof will be omitted.

In the nozzle device of the injection molding machine of this embodiment, the first inner nozzle 11 has the injection port 21a at the front end (the left side is the same as in FIGS. 5 and 6). The second inner nozzle 21 that contacts the valve seat 21b of the inner nozzle 11 and closes the first inner nozzle 11 forms a second flow chamber C11 communicating with the second injection device 12 between the first inner nozzle 11 and the second flow chamber C11. Then, the first inner nozzle 11 is inserted concentrically and movably in the axial direction. First inner nozzle 1
1 is an outer nozzle with respect to the second inner nozzle 21.

The needle 31 has a third inner chamber 21 in which a third flow chamber C11 communicating with the third injection device 22 is formed between the second inner nozzle 21 and the second inner nozzle 21 so as to be concentric with the inner nozzle 21. And movably in the axial direction. The second inner nozzle 21 is closed by the contact of the needle 31 with the valve seat 21b.

The second injection device 12 has nozzles 1 and 1
1d and 11d formed in 1 and the second inner nozzle 2
2 through the groove 21d formed in the first circulation chamber C1
The third injection device 22 is connected to the nozzles 1, 11,
It is configured to communicate with the third circulation chamber C21 via the circulation holes 1e, 11e, 21e formed in 21 and the groove 31e formed in the needle 31.

Further, the first drive cylinder 13 has piston rods 13b and 13d of the same diameter in front of and behind the piston 13c, and the cylinder body 13a is fixed to a fixed plate 56 attached to the rear end of the outer nozzle 1 with a bolt 55. The piston rod 13b on the front side is fixed to the rear end of the first inner nozzle 11 with a bolt 58 while being fixed with a bolt 57.

Like the first drive cylinder 13, the second drive cylinder 23 has Biston rods 23b and 23d having the same diameter in front of and behind the piston 23c, and the cylinder body 23a is provided with the piston rod 13d on the rear side of the first drive cylinder 13. The piston rod 23b on the front side with the first
The hollow cylinder 13c of the drive cylinder 13 and the piston rods 13b and 13d are inserted through the hollow cylinder 13c and fixed to the rear end of the second inner nozzle 21 with a bolt 59.

The third drive cylinder 33 includes a piston 33c.
Has piston rods 33b and 33d in front and rear thereof, and the cylinder body 33a is screwed to the piston rod 23d on the rear side of the second drive cylinder 23, and the piston rod 33b on the front side is connected to the hollow piston 2 of the second drive cylinder 23.
3c and the piston rods 23b and 23d, and is screwed to the rear end of the needle 31.

The front piston rods 13b, 23b,
33b is individually screwed to the pistons 13c, 23c and 33c. The center axes of the cylinder bodies of the drive cylinders 3, 13, 33, the pistons and the piston rods, the center axes of the nozzles 1, 11, 21 and the needle 31 coincide with each other.

A pair of limit switches 14a, 14b, 24a, 24b, 3 are provided on the rear side surfaces of the cylinder bodies 13a, 23a, 33a of the drive cylinders 13, 23, 33, respectively.
4a, 34b are attached by brackets 15, 25, 35, and rear piston rods 13d, 23d, 33 exposed to the outside of each drive cylinder 13, 23, 33
Dogs 16, 26, 36 are attached to the rear end of d. The dogs 16, 26, 36 are provided between the limit switches 14a, 14b, 24a, 24b, 34a, 34b.

Here, opening / closing of each nozzle 1, 11, 21 and limit switches 14a, 14b, 24a, 24b, 3
4a, 34b and the dogs 16, 26, 36 will be described. When the outer nozzle 1 is closed by the inner nozzle 11, the limit switch 14a is pushed by the dog 16 to output a close signal, and the outer nozzle 1 is opened. When
The limit switch 14b is pushed by the dog 16 and outputs an open signal.

Similarly, when the first inner nozzle 11 is closed by the second inner nozzle 21, the limit switch 24
When a is pushed by the dog 26 to output a close signal and the first inner nozzle 11 is opened, the limit switch 24b moves the dog 2
It is pressed at 6 and outputs an open signal. Further, when the second inner nozzle 21 is closed by the needle 31, the limit switch 34a is pushed by the dog 36 to give a closing signal, and when the second inner nozzle 21 is opened, the limit switch 34b is pushed by the dog 36. Output an open signal. Limit switch 1
4a, 14b, dog 16, limit switches 24a, 2
4b and the dog 26, and the limit switches 34a and 34b and the dog 36 respectively constitute detection means.

Reference numeral 40 is a hydraulic drive device. The hydraulic drive device moves each drive cylinder 13, 23, 33, and is connected to each drive cylinder 13, 23, 33 by a hydraulic circuit provided with hydraulic control valves 17, 27, 37.

Next, the operation of the nozzle device of the injection molding machine according to the present invention having the above structure will be described. FIG. 1 shows a state in which all the nozzles 1, 11, 21 are closed. From this state, when operating the first injection device 2 to inject resin, the first drive cylinder 13 is Actuate to the right in FIG. As a result, as shown in FIG. 2, the first inner nozzle 11 retreats to the right and separates from the valve seat 1b of the outer nozzle 1, and the outer nozzle 1 is opened, so that the resin can be injected. At this time, the second inner nozzle 21 and the needle 31 retract together with the first inner nozzle 11.

When the resin is injected by the operation of the second injection device 12, the second drive cylinder 23 is operated to the right from the state shown in FIG. By this operation, as shown in FIG. 3, the second inner nozzle 21 is retracted together with the needle 31 to move the first inner nozzle 21 to the first inner nozzle 21.
Since it separates from the valve seat 11b of the inner nozzle 11, the first inner nozzle 11 is opened and the resin can be injected.

Further, when the resin is injected by the operation of the third injection device 22, the third drive cylinder 33 is operated to the right from the state of FIG. By this operation, as shown in FIG. 4, the needle 31 retracts and separates from the valve seat 21b of the second inner nozzle 21, so that the second inner nozzle 21 is opened and the resin can be injected.

The above is the case where only one nozzle 1, 11, 21 is opened and the resin of the injection device 2, 12, 22 is independently injected, but two or more drive cylinders 13, 23, 3 are used.
By retreating 3, the outer nozzle 1 and the first inner nozzle 11, the outer nozzle 1 and the second inner nozzle 21, the first inner nozzle 11 and the second inner nozzle 21, all the nozzles 1, 11, 21 , Two or more nozzles can be opened to simultaneously inject two or more kinds of resins. The opening / closing of each nozzle can be known by the detecting means, but can be easily known visually from the movement interval of the drive cylinder.

In the present invention, the number of nozzles provided may be two as in the conventional case or four or more. It goes without saying that when the number of nozzles used is reduced, the drive cylinders related to the nozzles are omitted, and when the number of nozzles is increased, the drive cylinders are also added together.

Further, in the illustrated nozzle device, the inner nozzles 11 and 11 are connected to the injection ports 1a and 11a of the outer nozzles 1 and 11, respectively.
1 has a structure in which it is fitted, but it is also possible to adopt the conventional example shown in FIGS. 5 and 6 without doing so. Paired piston rods 13b, 13d, 23b, 23d, 33
b and 33d do not have to have the same diameter.

[0035]

As described above, in the nozzle device of the injection molding machine according to the present invention, the outer nozzle having the injection opening at the front end is in contact with the valve seat of the outer nozzle having the injection opening at the front end. The inner nozzle, which closes the outer nozzle, forms a first flow chamber communicating with the first injection device between the outer nozzle and the first nozzle, and is inserted concentrically with the outer nozzle and axially movable. And a needle that contacts the valve seat of the inner nozzle and closes the inner nozzle, forms a second flow chamber communicating with the second injection device between the inner nozzle and the needle, and is concentric with the inner nozzle and axially. A movable cylinder is attached to the inner nozzle so as to move the inner nozzle in the axial direction with respect to the outer nozzle, and the needle is attached to the needle in the axial direction. Against In a nozzle device of an injection molding machine provided with a second drive cylinder for moving the first drive cylinder, the cylinder body of the first drive cylinder is located at the rear end of the outer nozzle, and the central axis of the cylinder body is defined as the central axis of the outer nozzle. The first piston rod whose center axis is substantially aligned with the center axis of the inner nozzle while being fixed substantially
The second drive cylinder is connected to the rear end of the inner nozzle, and the cylinder body of the second drive cylinder is the second piston rod of the first drive cylinder, and the center axis of the cylinder body is the center axis of the second piston rod. The piston rod whose center axis is substantially aligned with the center axis of the needle, and is inserted into the shaft holes formed in the first and second piston rods and piston of the first drive cylinder. Since the needle is connected to the rear end of the needle, a moment does not act when the nozzle and the needle are driven by the drive cylinder, so that the nozzle always operates smoothly. Therefore, it is not necessary to increase the rigidity of the constituent members or to give special consideration to management.

Further, since it is not necessary to increase the diameter of the drive cylinder for actuating the nozzle and the needle, the injection device can be brought close to the nozzle and the entire device can be compacted.
The amount of residual resin can be reduced. Moreover, the open / closed state of the nozzle can be easily known visually from the movement interval of each drive cylinder. Since the piston rod on the rear side of each drive cylinder is exposed to the outside, it is easy to automatically provide automatic control by providing the cylinder body and the rear piston rod with detection means including a limit switch and a dog.

[Brief description of drawings]

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

FIG. 2 is a schematic cross-sectional view showing an open state of an outer nozzle of a nozzle device of the present injection molding machine.

FIG. 3 is a schematic cross-sectional view showing an open state of the first inner nozzle of the nozzle device of the present injection molding machine.

FIG. 4 is a schematic cross-sectional view showing an open state of a second inner nozzle of the nozzle device of the present injection molding machine.

FIG. 5 is a cross-sectional view of a nozzle device of a conventional injection molding machine.

FIG. 6 is a cross-sectional view of another conventional nozzle device.

[Explanation of symbols]

 1 Outer Nozzle 1a Injection Port 1b Valve Seat 2 Injection Device 11 Inner Nozzle (Outside Nozzle) 11a Injection Port 11b Valve Seat 12 Injection Device 13 Drive Cylinder 13a Cylinder Body 13b Piston Rod 13c Piston 13d Piston Rod 14a Limit Switch 14b Limit Switch 16 Dog 21 Inner Nozzle 21a Injection Port 21b Valve Seat 22 Injection Device 23 Drive Cylinder 23a Cylinder Body 23b Piston Rod 23c Piston 23d Piston Rod 24a Limit Switch 24b Limit Switch 26 Dog 31 Needle 33 Drive Cylinder 33a Cylinder Body 33b Piston Rod 33c Piston Rod 33d 34a Limit switch 34b Limit switch 36 Dog C1 Distribution chamber C11 Distribution channel C21 distribution chamber

Claims (5)

[Claims] 1. An outer nozzle having an injection port at a front end,
An inner nozzle having an injection port at the front end and contacting the valve seat of the outer nozzle to close the outer nozzle forms a first flow chamber communicating with the first injection device with the outer nozzle and is concentric with the outer nozzle. A needle that is inserted into the inner nozzle so as to be movable in the axial direction and that is in contact with the valve seat of the inner nozzle and that closes the inner nozzle.
A flow chamber is formed between the inner nozzle and the inner nozzle so as to be inserted concentrically with the inner nozzle and to be movable in the axial direction, and the inner nozzle is moved in the axial direction with respect to the outer nozzle. In the nozzle device of the injection molding machine, the first drive cylinder is attached, and the needle is provided with a second drive cylinder for axially moving the needle with respect to the inner nozzle. A first piston rod in which the cylinder body is fixed to the rear end of the outer nozzle so that the center axis of the cylinder body substantially coincides with the center axis of the outer nozzle and the center axis coincides with the center axis of the inner nozzle. Is connected to the rear end of the inner nozzle, and the second drive cylinder has a cylinder body whose second piston rod is the second piston rod of the first drive cylinder. The central axis of the cylinder body second
A piston rod is formed on the first piston rod, the second piston rod and the piston of the first drive cylinder, the piston rod being fixed substantially in line with the central axis of the piston rod and having the central axis substantially aligned with the central axis of the needle. A nozzle device of an injection molding machine, characterized in that the nozzle device is inserted through the shaft hole and connected to the rear end of the needle. 2. The nozzle device of an injection molding machine according to claim 1, wherein the needle is a nozzle. 3. The nozzle device for an injection molding machine according to claim 1, wherein the second drive cylinder is provided with a second piston rod. 4. A detection means for detecting axial movement of the second piston rod with respect to the cylinder body is provided between the cylinder body of the drive cylinder and the second piston rod of the drive cylinder. A nozzle device for an injection molding machine according to claim 1, 2, or 3. 5. The nozzle device for an injection molding machine according to claim 4, wherein the detection means includes a limit switch attached to the cylinder body of the drive cylinder and a dog attached to the piston rod.