JPH09141690A - Multicolor injection molding machine - Google Patents

Abstract

(57) [Abstract] [PROBLEMS] To easily switch between single molding and sandwich molding using a single mold. An injection molding machine for co-injecting two or more kinds of resins, in which an injection unit is disposed so as to be slidable in the front and rear direction so as to face a fixed mold attached to a fixed platen, and the fixed mold is also provided. A multicolor molding block having a resin passage capable of communicating between the injection unit and the injection unit was interposed, and the block was movably provided between the injection unit and the fixed mold.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multicolor injection molding apparatus capable of performing single molding or sandwich molding while using a single molding machine.

[0002]

2. Description of the Related Art Conventionally, an inner nozzle is provided in the center of an outer nozzle, and a resin which is a core of a molded product is injected from the inner nozzle and a resin which is a surface layer of the molded product is simultaneously injected from the outer nozzle to obtain a cross-sectional structure. Methods for molding multi-layer molded articles are already known. First, FIG. 11 and FIG.
As described in Japanese Patent No. 143820, the swivel bases 3a and 3b, which are longer than the two support bases, are provided on the lateral moving device that is disposed so as to face the fixed platen 5 of the mold clamping device. ing. Two sets of injection units 4a and 4b are slidably arranged on the swivel bases 3a and 3b. Further, in the lateral movement device, the injection units 4a and 4b have nozzle insertion holes 5a.
5c, a position facing both the left and right two nozzle insertion holes 5a, 5c, and either one of the injection units 4a, 4b.
Is provided with a drive unit and a stopper mechanism for moving the nozzle to a position facing the central nozzle insertion hole 5b. And the injection units 4a and 4b are T for sandwich molding.
The nozzle 30 has replaceable nozzle contact portions 4a 'and 4b'.

FIG. 13 is disclosed in Japanese Patent Publication No. 39-19044, in which two or more injection units capable of individually melting and injecting thermoplastic materials of two or more colors and independent material passages. It is composed of injection nozzles that are connected to each other via a large number and are concentrically arranged. Each injection unit can independently adjust the temperature, injection pressure, injection speed, injection amount, and injection time of the raw material at the time of injection. Thus, a multicolor molded product having various changes such as a marble pattern and a blur pattern is obtained.

FIG. 14 is disclosed in Japanese Patent Laid-Open No. 4-43011, in which an injection hole 3 is formed in a sandwich molding die 1, and a nozzle block 10 is attached / detached in / from a holding portion 2a via a holding member 11. Freely installed, its front end 10
The single nozzle portion 12 is formed in a and the protruding nozzle portion 12 is formed.
a communicates with and is in contact with the injection hole 3. A first material passage 13 and a second material passage 14 are provided in the nozzle block 10.
Is provided and a rotatable open / close valve portion 16 is provided at an intermediate position of the second material passage 14, and the open / close valve portion 16 is rotated by the operation of an actuator so that the through hole 15 of the open / close valve portion 16 is made into the second material passage. The second material passage 14 is selectively opened and closed by communicating with or not communicating with 14. Thus, the two kinds of materials are injected into the mold cavity.

FIG. 15 is disclosed in Japanese Patent Laid-Open No. 4-316818, in which the resin 26 for the skin layer is injected from the first hot runner 10b into the cavities C of the molding dies 18, 20 and then the first hot By closing the resin passage between the runner 10b and the cavity C, the skin layer resin 2
Injection of the resin 6 for the skin layer, and injecting the core layer resin 28 into the cavity C of the molding dies 18, 20 from the second hot runner 12b at a predetermined timing from the injection start of the skin layer resin 26 to the injection completion. The sandwich molded article is molded by.

[0006]

However, FIGS. 11 to 15 have the following problems. First, Japanese Patent Laid-Open No. 2-14
According to the one described in Japanese Patent No. 3820, when attempting to perform single molding with the T-shaped nozzle 30 attached, even the heating cylinder of the unused first injection unit 4a or second injection unit 4b must be heated. It is a waste of energy. Moreover, the larger the machine, the greater the degree. Further, in order to solve these problems, if the T-shaped nozzle 30 is removed at the time of single molding and an independent single nozzle is attached to each injection unit, extra work such as removal and installation of the nozzle is required, which is not efficient. There is.

Further, in the one disclosed in Japanese Patent Publication No. 39-19044, although the single molding by the main heating cylinder constituting the first injection unit A does not cause any problem,
If a single molding is attempted using the sub-heating cylinder that constitutes the injection unit A, the main heating cylinder that constitutes the first injection unit A must also be heated at the same time, which is wasteful in terms of heat quantity.

In the one disclosed in Japanese Patent Laid-Open No. 4-43011, a single nozzle portion 12 is formed at the front end 10a of a nozzle block 10, and a projecting nozzle portion 12a at the tip of this single nozzle portion 12 has an injection hole 3a. However, even if the resin leaks from the abutting surface, it is not known for a while, and even if the resin leaks, the nozzle block 10 is immediately removed from the fixed platen 2. There is a problem that it is impossible to move to.

Further, the structure described in Japanese Patent Application Laid-Open No. 4-316818 has a complicated structure because the resin switching device is incorporated in the fixed mold 18, and therefore the structure for sandwich molding is used at the time of sandwich molding. Since there is no choice but to use the fixed mold 18 and to prepare a separate mold for single molding at the time of single molding, there is a drawback that the compatibility of the mold is poor.

The present invention has been made in view of the above problems, and an object of the present invention is to enable easy switching between single molding and sandwich molding using a single mold and to prevent resin leakage during molding. It is an object of the present invention to provide a multi-color injection molding device capable of easily monitoring the temperature.

[0011]

In order to achieve the above object, in the first aspect of the present invention, there is provided an injection molding machine for co-injecting two or more kinds of resins, which is fixed to a fixed platen. The injection unit is disposed so as to be slidable forward and backward so as to face the mold, and a multicolor molding block having a resin passage capable of communicating between the fixed mold and the injection unit is interposed,
The block was movably provided between the injection unit and the fixed mold. Further, in the second invention, two or more kinds of resins are co-injected, and a plurality of injection units and the first base on which the injection units are mounted are respectively slid back and forth in opposition to the fixed mold attached to the fixed platen. An injection molding machine movably arranged, wherein one end of a first hydraulic cylinder is rotatably supported on the injection unit side of the fixed plate and one end of a piston engaged with the first hydraulic cylinder is injected. The unit is placed, and the linear guide is rotatably supported by a slidable first base and is mounted on a support base integrally formed with the first base on the front side of the first base. A color molding block is fixedly mounted, and one end of a second hydraulic cylinder is rotatably supported in front of the first base and one end of a piston engaging with the second hydraulic cylinder is mounted with an injection unit. Do with linear guy The upper part is rotatably supported by a slidable moving base, and the fixed mold and the block and the injection unit can be connected or detached from each other by expanding and contracting the piston rods of the first hydraulic cylinder and the second hydraulic cylinder. And Further, according to a third aspect of the present invention, which is mainly based on the second aspect, an injection molding machine that co-injects two or more kinds of resins, is provided with an injection unit that is disposed to face a fixed mold attached to a fixed plate. A linear guide mounted on the machine base is slidable back and forth, and a block having a resin passage that can communicate between the fixed mold and the injection unit is interposed, and the block is fixed to a holding table. The holding table is arranged so as to be slidable back and forth on a linear guide, and a projecting portion is provided on the machine base located in front of the injection unit, and one end of the second hydraulic cylinder can be freely rotated on the projecting portion. One end of a piston that is axially supported on the second hydraulic cylinder and is engaged with the second hydraulic cylinder is rotatably supported on a moving table on which an injection unit is mounted, and the piston rod of the second hydraulic cylinder expands and contracts to form a fixed mold. Blocks and The output unit can be connected or detached from each other, and at least one injection unit is provided with a hook on the front outer periphery of the heating cylinder, and a locking member is provided at a position rearward of the outer periphery of the heating cylinder slightly separated from the hook. When the injection unit is retracted, the block and the locking member are engaged with each other to combine the block and the injection unit, and when the injection unit is advanced, the block and the locking member are released from each other so that the block and the injection unit are released. And so that they can be separated.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION As described in the above configuration, the machine base, the first base, the moving base, and the injection unit are arranged in an overlapping manner, and the injection units arranged in the shape of a figure are arranged in a superposed manner. Hydraulic cylinders are arranged between the bases and between the first base and the moving base, and the action of the hydraulic cylinders brings the first base and the moving base into contact with and separates from the fixed platen. By connecting or disconnecting the multicolor material molding block movably arranged between the fixed platen and the injection unit, while preventing resin leakage depending on the single molded product and the sandwich molded product, and Switching can be done easily.

[0013]

EXAMPLES Specific examples of the multicolor injection molding apparatus according to the present invention will be described in detail below with reference to FIGS.

FIG. 1 is a plan view of a multicolor injection molding apparatus according to the present invention, FIG. 2 is a side sectional view taken along the lines AA of FIG. 1, and FIG. FIG. 5 is a plan view showing a state, FIG. 4 is a side sectional view seen from BB of FIG. 3, and FIG.
FIG. 6 is a plan view of the other multicolor injection molding apparatus of the present invention when the injection unit is retracted in a state in which the locking member is locked to the hook, and FIG. 6 is a side cross-sectional view as seen from CC of FIG. FIG. 7 is a plan view of another multicolor injection molding apparatus of the present invention in a state where injection can be started, FIG. 8 is a side sectional view taken from D to D of FIG. 7, and FIG. 9 is a side view from E to E of FIG. FIG. 10 is a cross-sectional view, and FIG. 10 is an operation explanatory view showing a molded state of a molded product having an outer layer and an inner layer.

First, a first embodiment will be described with reference to FIGS. [Embodiment 1] Reference numeral 5 is a fixed plate of a mold clamping device (not shown) provided on the left side (referred to as front) of the injection device 1 in the figure. The fixed board 5 has an opening 6 of a predetermined size, and a multicolor molding block 10 interposed between a fixed mold 7 and the injection unit 2 is fixedly mounted on the support 8 in the opening 6. Has been done. Reference numeral 41 is a movable plate, and 9 is a movable mold.

The injection unit 2 is composed of two first injection units 2A and 2B,
As shown in FIG. 1, the injection units 2A and 2B are installed so as to have an eight-character shape.
A and 2B are placed on the first base 39. Also,
Two sets of linear guides 38A, 38 are provided on the first base 39.
B is laid and these linear guides 38A, 38B
The injection unit 2 fixed on the moving bases 11A and 11B above
A and 2B can be moved back and forth together with the movable bases 11A and 11B. The forward and backward movements of the injection units 2A and 2B are rotatably supported by pin support shafts between the support base 8 and the movable bases 11A and 11B, which are erected forwardly at the tip of the first base 39. This is performed by expanding and contracting the piston rod 44a of the two hydraulic cylinder 44. Reference numeral 42 indicates a machine base on which the first base 39 is placed.

A multicolor molding block 10 is fixedly mounted on the support base 8 at the tip of the first base 39. Also,
A pair of linear guides 43 is arranged on the machine base 42, and the linear guide 43 is mounted on the machine base 42.
A first base 39 on which A and 2B are placed is provided so as to be movable back and forth. The first base 39 is moved back and forth in such a manner that one end is on the end surface of the fixed plate 5 on the injection device 1 side and the other end is on the first base 3 side.
Piston rod 40a of the first hydraulic cylinder 40, which is rotatably supported by a pin support shaft between the lower convex portions 39a of 9
It is designed to be performed by expanding and contracting.

The multi-color molding block 10 is provided with a first material flow channel 45 connected to the second injection unit 2B and a second resin flow passage 46 connected to the first injection unit 2A. Inside the block nozzle 15 arranged on the stationary platen 5 side of the block 10, the first resin passage 45 is located in the central portion and the second resin passage 46 is located in the outer peripheral portion. The two resin passages 46 and the inner and outer annular passages are concentrically arranged. In addition,
The multicolor molding block 10 is heated by an appropriate heating means (not shown).

Therefore, when the piston rod 40a of the first hydraulic cylinder 40 and the piston rod 44a of the second hydraulic cylinder 44 are respectively retracted, as shown in FIG. 3, the spool 14 of the fixed mold 7 and the multicolor molding block 10 are separated. The block nozzle 15 comes into contact with the abutment portion 13 (13A, 13B) of the multicolor molding block 10 and the injection units 2A, 2B.
The injection nozzles 12A and 12B come into contact with each other and are connected to each other, and are in a closed state. On the contrary, when the piston rod 40a of the first hydraulic cylinder 40 and the piston rod 44a of the second hydraulic cylinder 44 are respectively extended, the spool 14 of the fixed mold 7 and the block of the multicolor molding block 10 are blocked as shown in FIG. The nozzle 15 is separated, and the contact portion 13 (13A, 13B) of the multi-color molding block 10 and the injection nozzles 12A, 12B of the injection units 2A, 2B are separated from each other, and an open state is exhibited.

Of the inner and outer annular resin passages provided in the block nozzle 15, the second resin passage 46 located on the outer side and the first resin passage 45 located on the inner side are both at the tip opening 26 of the block nozzle 15. It merges and continues to runner 27. In addition, shut-off valves 23A and 23B for opening and closing the first resin passage 45 and the second resin passage 46, respectively, are provided, and are operated by a connecting member (not shown) from the upper surface of the multicolor molding block 10. It is designed to open and close. Reference numeral 21 indicates a cavity portion.

First, the operation of sandwich molding using the multicolor injection molding apparatus having the structure shown in Embodiment 1 will be described. Clamping subsequent to the mold closing of the fixed mold 7 and the movable mold 9 is performed by an unillustrated appropriate mold clamping device (for example, a direct pressure type or toggle type mold clamping means is used). Next, the piston rod 40a of the hydraulic cylinder 40 is retracted to move the first base 39 to the fixed mold 7 side, and the block nozzle 15 of the multicolor molding block 10 is brought into contact with the spool 14 of the fixed mold 7. .

Further, the piston rod 44a of the second hydraulic cylinder 44 is retracted so that the movable bases 11A and 11B on which the injection units 2A and 2B are respectively mounted are brought into contact with the contact portions 13A and 13B of the multicolor material molding block 10. Fixed mold 7, multicolor molding block 10 and injection unit 2 in contact with each other
Connect A and 2B. As shown in FIG. 10 (1), with the shutoff valve 23A opened (at this time, the shutoff valve 23B is closed), the first injection unit 2A is inserted into the cavity 21 formed between the molds 7 and 9. The screw is advanced to inject and fill resin A as a skin material through the second resin passage 46.

Then, the skin layer, that is, the outer layer is formed by injection-filling the resin A into the cavity 21. When forming a molded product having an outer layer and an inner layer by sandwich molding, a virgin material is used as the A resin, and a recycled material or a different material or a resin material of a different grade is used as the B resin that forms a so-called inner layer, which will be described later. To use.

After injection of a predetermined amount of molten resin into the cavity 21, the shut-off valve 23B is opened (at this time, the shut-off valve 23A is closed) as shown in FIG. 10 (2). The screw of the 2-injection unit 2B is advanced to allow the B resin as the core material to pass through the first resin passage 45.
An appropriate amount is injected and filled into the cavity 21 through Thereafter, as shown in FIG. 10C, the shut-off valve 23A is opened again (at this time, the shut-off valve 23B is closed), and the cavity 21 is formed in the cavity 21 formed between the molds 7 and 9. By advancing the screw of the 1 injection unit 2A and injecting and filling the A resin as the skin material through the second resin passage 46, the B resin as the core material is confined by the A resin as the skin material, and the outer layer・
A molded article with an inner layer is obtained. After the injection and filling of the A resin is completed, the screw on the first injection unit 2A side is moved forward to apply a holding pressure to the molten resin in the cavity 21.

After the pressure holding is completed, the shutoff valve 23A is closed (the shutoff valve 23B is already kept closed), and the first injection unit 2A and the second injection unit 2B both perform the measurement in the next cycle. Both molds 7, 9
After cooling for a predetermined time, both molds 7 and 9 are opened to take out the product.

Next, the operation in the case of single molding using the multicolor injection molding apparatus having the structure shown in the first embodiment will be described.

Clamping of the fixed mold 7 and the movable mold 9 following the mold closing is performed by an appropriate mold clamping device (not shown) (for example, a direct pressure type or toggle type mold clamping means is used).
Next, the piston rod 40a of the hydraulic cylinder 40 is retracted to move the first base 39 to the fixed mold 7 side, and the block nozzle 15 of the multicolor molding block 10 is fixed to the fixed mold 7.
Abutting on the spool 14.

Further, the moving base 11A on which the piston rod 44a of the second hydraulic cylinder 44 is retracted and the first injection unit 2A is mounted is attached to the contact portion 1 of the multicolor molding block 10.
Fixed mold 7, multicolor molding block 10 brought into contact with 3A
And the 1st injection unit 2A is connected. However, the second injection unit 2B extends the piston rod 44a of the second hydraulic cylinder 44 to separate it from the multicolor molding block 10 and turns off the heating heater of the second injection unit 2B. Then shutoff valve 23
Keep B closed.

After confirming the opening of the shutoff valve 23A of the second resin passage 46 in this way, the screw of the first injection unit 2A is moved forward to inject and fill the cavity 21 with the molten resin, and subsequently the forward limit position of the screw is maintained. The holding pressure is applied while it is held. After this shutoff valve 23A
Is closed, and in preparation for the next cycle, the screw of the first injection unit 2A is rotated and retracted to perform measurement. After a predetermined cooling time has elapsed, both molds 7 and 9 are opened and the product is taken out.

Next, a second embodiment will be described with reference to FIGS. [Embodiment 2] Reference numeral 5 is a fixed plate. The fixed plate 5 has an opening 6 of a predetermined size, and a multicolor molding block 10 interposed between the fixed mold 7 and the injection unit 2 (2A, 2B) can be moved back and forth in the opening 6. It is installed in. Reference numeral 41 is a movable plate, and 9 is a movable mold.

The injection unit 2 is composed of two injection units 2A and 2B. As shown in FIG. 5, the injection units 2A and 2B are installed on a machine base 42 indicated by reference numeral 42 so as to form an eight-character shape. ing. The first injection unit 2A is mounted on a machine base 42 on a pair of linear guides 38A so as to be movable back and forth. on the other hand,
The injection unit 2B is movable back and forth on a first base 39 arranged on the machine base 42 via a linear guide 38B. The rear end portion of the first base 39 is bored, and the turning shaft 22 is inserted therethrough to insert the machine base 4 into the machine base 4.
It is planted in 2. For this reason, the first base 39 is restricted from moving back and forth by the swivel shaft 22, but can be swung left and right on the first base 39 while the second injection unit 2B is placed around the swivel shaft 22. It is like this.

Reference numeral 24 is a steadying and position adjusting bolt, and when the multicolor molding block 10 is advanced and the block nozzle 15 is brought into contact with the spool 14, the injection nozzle 12B is sufficiently located between the contact portions 13B. Since the resin does not come into contact with the contact surface, the problem that the resin leaks from the contact surface does not occur, and the pair of left and right steady stop bolts 24 are moved forward and backward to move the injection nozzle 12B. The contact portion 13B is sufficiently abutted.

The forward and backward movements of the injection units 2A and 2B are performed by the projecting portion 28 of the machine base 42 near the fixed plate 5 and the movable table 1.
A piston rod 44a of a second hydraulic cylinder 44 rotatably supported by a pin support shaft between 1A and 11B.
It is designed to be performed by expanding and contracting.

A multicolor molding block 10 is arranged between the stationary platen 5 and the injection units 2A and 2B. The multi-color molding block 10 is fixed on a pair of linear guides 17 arranged on the machine base 42 to a holding base 18 which is movable back and forth. A hook 16a protruding from the heating cylinder 19 is fixed to the tip of the heating cylinder 19 of the first injection unit 2A.
A locking member 16b standing upright on the holding table 18 is fixed to a rear position of the heating cylinder 19 slightly separated from the above.

On the other hand, when the piston rods 44a of the second hydraulic cylinder 44 are respectively retracted, the spool 14 of the fixed mold 7 and the block nozzle 15 of the multicolor molding block 10 come into contact with each other as shown in FIG. Molding block 10
Abutting portion 13 (13A, 13B) and injection unit 2A,
The 2B injection nozzles 12A and 12B are in contact with each other and are connected to each other, and are in a closed state. Also, FIGS.
Contrary to the above, when the piston rod 44a of the second hydraulic cylinder 44 is extended and the first injection unit 2A is retracted, the hook 16a is locked to the locking member 16b, and the first injection unit 2A The multicolor molding block 10 is also retracted together with the retraction. Therefore, the spool 14 of the fixed mold 7 and the multicolor molding block 1
The block nozzles 0 of 0 are separated from each other and are in an open state.

The multi-color molding block 10 is provided with a first resin passage 45 connected to the second injection unit 2B and a second resin passage 46 connected to the first injection unit 2A. The inside of the block nozzle 15 disposed on the stationary plate 5 side of 10 has the first resin passage 45 at the center and the second resin passage 46 at the outer periphery. The resin passage 46 and the inner and outer annular passages are concentrically arranged.

Of the inner and outer annular resin passages provided in the block nozzle 15, the second resin passage 46 located on the outer side and the first resin passage 45 located on the inner side are both at the tip end port 26 of the block nozzle 15. It merges and continues to runner 27. In addition, shut-off valves 23A and 23B for opening and closing the first resin passage 45 and the second resin passage 46, respectively, are provided, and are operated by a connecting member (not shown) from the upper surface of the multicolor molding block 10. It is designed to open and close. Reference numeral 21 indicates a cavity portion.

First, the operation of twin molding using the multicolor injection molding apparatus having the structure shown in the second embodiment will be described. Clamping subsequent to the mold closing of the fixed mold 7 and the movable mold 9 is performed by an unillustrated appropriate mold clamping device (for example, a direct pressure type or toggle type mold clamping means is used). Next, when the piston rod 44a of the second hydraulic cylinder 44 is retracted, the movable table 11A moves to the fixed mold 7 side while sliding on the linear guide 38A, but at this time, the injection nozzle 12A of the first injection unit 2A. Is pressed against the abutting portion 13A of the multicolor molding block 10, and the holding base 18 to which the multicolor molding block 10 is fixed is the linear guide 1
It moves to the fixed mold 7 side while sliding on 7, and finally the block nozzle 15 is brought into contact with the spool 14 of the fixed mold 7.

Subsequently, when the piston rod 44a of the second hydraulic cylinder 44 on the second injection unit 2B side is retracted, the second injection unit 2B moves forward while sliding on the linear guide 38B, and finally the second injection unit 2B. The injection nozzle 12B comes into contact with the contact portion 13B, and the fixed mold 7, the multicolor molding block 10 and the injection units 2A and 2B are in a connected state. However, if the injection nozzle 12B of the second injection unit 2B abuts against the abutting portion 13B when it is not abutting sufficiently, resin leakage may occur from this abutting surface. It is important to sufficiently adjust the position of the first base 39 with the steady rest prevention bolts 24 in advance.

Then, with the shut-off valve 23A open (the shut-off valve 23B closed at this time), the screw of the first injection unit 2A is moved forward into the cavity 21 formed between the molds 7 and 9. As a skin material, resin A is injected and filled through the second resin passage 46. Then, by injection-filling the resin A into the cavity 21, a skin layer, that is, an outer layer is formed. When forming a molded product having an outer layer and an inner layer by sandwich molding, a virgin material is used as the A resin, and a recycled material or a different material or a resin material of a different grade is used as the B resin that forms a so-called inner layer, which will be described later. To use (Fig. 1
0 (1)).

Next, a predetermined amount of molten resin A is added to the cavity 21.
After injection and filling into the inside, as shown in FIG. 10 (2), the screw of the second injection unit 2B is advanced with the shut-off valve 23B opened (at this time, the shut-off valve 23A is closed) to form a core material. B resin of the first resin passage 4
An appropriate amount is injected and filled into the cavity 21 through the 5. Thereafter, as shown in FIG. 10C, the shut-off valve 23A is opened again (at this time, the shut-off valve 23B is closed), and the cavity 21 is formed in the cavity 21 formed between the molds 7 and 9. By advancing the screw of the 1 injection unit 2A and injecting and filling the A resin as the skin material through the second resin passage 46, the B resin as the core material is confined by the A resin as the skin material, and the outer layer・ A molded product with an inner layer is obtained. After the injection and filling of the A resin is completed, the screw on the first injection unit 2A side is moved forward to apply a holding pressure to the molten resin in the cavity 21.

After the pressure holding is completed, the first injection unit 2A and the second injection unit 2B both perform the measurement in the next cycle in a state where the shut-off valve 23A is closed (the shut-off valve 23B is already kept closed). Both molds 7, 9
After cooling for a predetermined time, both molds 7 and 9 are opened to take out the product.

Next, the operation of single molding using the multicolor injection molding apparatus having the structure shown in the second embodiment will be described.

Clamping of the fixed mold 7 and the movable mold 9 is performed by an unillustrated appropriate mold clamping device (for example, a direct pressure type or toggle type mold clamping means is used).
Next, when the piston rod 44a of the second hydraulic cylinder 44 is retracted, the movable table 11A moves to the fixed mold 7 side while sliding on the linear guide 38A, but at this time, the injection nozzle 12A of the first injection unit 2A. The tip of the is pressed in a state of contacting the contact portion 13A of the multicolor molding block 10,
The holding table 18 to which the multicolor molding block 10 is fixed moves to the fixed mold 7 side while sliding on the linear guide 17, and finally the block nozzle 15 abuts on the spool 14 of the fixed mold 7. Let

However, in the second injection unit 2B, the piston rod 44a of the second hydraulic cylinder 44 is extended to be separated from the multicolor molding block 10, and the heating heater of the second injection unit 2B is turned off. . Next, the shutoff valve 23B is closed.

After confirming the opening of the shutoff valve 23A of the second resin passage 46 in this way, the screw of the first injection unit 2A is advanced to inject and fill the cavity 21 with the molten resin, and then the advance limit position of the screw is maintained. The holding pressure is applied while it is held. After this shutoff valve 23A
Is closed, and in preparation for the next cycle, the screw of the first injection unit 2A is rotated and retracted to perform measurement. After a predetermined cooling time has elapsed, both molds 7 and 9 are opened and the product is taken out.

After the production of a predetermined molded product is completed,
When the piston rod 44a of the second hydraulic cylinder 44 is extended in an attempt to separate the multicolor molding block 10 from the fixed mold 7, the heating cylinder 19 of the first injection unit 2A.
The holding table 18 on which the multicolor molding block 10 is placed by the hook 16a fixed to the tip of the
Slides on the linear guide 17 and retreats together with the first injection unit 2A.

In this embodiment, as shown in FIG. 5, the first
The hook 16a protruding from the tip of the heating cylinder 19 of the injection unit 2A is retracted in a state of being locked by the locking member 16b having a rectangular plate piece. However, without being limited to this, for example, locking is possible. An expandable piston rod is engaged with the cylinder instead of the member 16b so as to engage with the hook 16a when the piston rod extends.
The structure may be such that the hook 16a is detached when the piston rod is retracted, or another structure may be adopted.

[0049]

As apparent from the above description, the present invention has the following advantages. In other words, during single molding, the hydraulic cylinder can be extended to easily separate the injection unit from the block for multicolor molding, so there is no need to heat up even the injection unit that is stopped, and power consumption can be reduced. Can be suppressed. Since the screw replacement of the injection unit can be performed in the same manner as the single molding machine, the screw replacement time and labor can be greatly reduced. The block nozzle of the multi-color molding block and the spool of the fixed mold can freely come into contact with and separate from each other, and even if a resin leak occurs during this period, quick resin leak prevention can be performed. Switching from single molding to sandwich molding can be easily done via the multicolor molding block, and molds do not have to be prepared separately for single or sandwich, thus increasing mold compatibility.

[Brief description of the drawings]

FIG. 1 is a plan view of a multicolor injection molding apparatus according to the present invention.

FIG. 2 is a side sectional view as seen from AA of FIG.

FIG. 3 is a plan view showing a state in which the multicolor injection molding apparatus of the present invention can start injection.

FIG. 4 is a side cross-sectional view as seen from BB of FIG.

FIG. 5 is another multicolor injection molding apparatus of the present invention.

6 is a side cross-sectional view as seen from CC of FIG.

FIG. 7 is a plan view of the injection device in a state in which injection can be started according to the second embodiment.

FIG. 8 is a side cross-sectional view as seen from D to D in FIG. 7.

9 is a side cross-sectional view as seen from E to E of FIG.

FIG. 10 is an operation explanatory view showing a molding state of a molded product having an outer layer and an inner layer.

FIG. 11 is a conventional multicolor injection molding apparatus.

FIG. 12 is a front view of FIG. 11;

FIG. 13 is a conventional multicolor injection molding apparatus.

FIG. 14 is a conventional multicolor injection molding apparatus.

FIG. 15 is a conventional multicolor injection molding apparatus.

[Explanation of symbols]

 1 injection molding machine 2 injection unit 2A first injection unit 2B second injection unit 5 fixed plate 6 opening 7 fixed mold 8 support base 9 movable mold 10 multicolor molding block 11 (11A, 11B) moving base 12 ( 12A, 12B) Injection nozzle 13 (13A, 13B) Contact part 14 Spool (fixed mold) 15 Block nozzle 16a Hook 16b Locking member 17 Linear guide 18 Holding table 19 Heating cylinder 21 Cavity 22 Swivel axis 23A, 23B Shut Off valve 26 Tip port 27 Runner 38A, 38B Linear guide 39 First base 40 First hydraulic cylinder 41 Movable plate 42 Machine base 43 Linear guide 44 Second hydraulic cylinder 45 First resin passage 46 Second resin passage

Claims (3)

[Claims] 1. An injection molding machine for co-injecting two or more kinds of resins, wherein an injection unit is provided so as to be slidable back and forth, facing a fixed mold attached to a fixed platen. A multicolor injection molding apparatus, wherein a multicolor molding block having a resin passage capable of communicating between the mold and the injection unit is interposed, and the block is movably provided between the injection unit and a fixed mold. 2. A plurality of injection units and a first base on which the injection units are mounted can be slid back and forth, respectively, while co-injecting two or more kinds of resins and facing a fixed mold attached to a stationary platen. In the arranged injection molding machine, one end of a first hydraulic cylinder is rotatably supported on the injection unit side of the fixed plate, and one end of a piston engaging with the first hydraulic cylinder is mounted on the injection unit. And linearly guide the linear guide to the slidable first base,
On the front side of the first base, a multicolor molding block is fixedly mounted on a support base integrally formed with the first base, and one end of a second hydraulic cylinder is rotated in front of the first base. An injection unit is mounted on one end of a piston which is freely rotatably supported and which is engaged with the second hydraulic cylinder, and rotatably rotatably rotatably supported on a linearly slidable moving table.
A multicolor injection molding apparatus characterized in that a fixed die, a block and an injection unit can be connected or detached from each other by expanding and contracting each piston rod of the first hydraulic cylinder and the second hydraulic cylinder. 3. An injection molding machine for co-injecting two or more kinds of resins, wherein an injection unit opposed to a fixed mold attached to a fixed plate is mounted on a linear guide arranged on a machine base. It is slidable back and forth, and a block having a resin passage that can communicate between the fixed mold and the injection unit is interposed, and the block is fixed to a holding base, and the holding base slides back and forth on a linear guide. Arrange freely, and further,
A projecting portion is provided on a machine base located in front of the injection unit, and one end of a second hydraulic cylinder is rotatably supported by the projecting portion and one end of a piston that engages with the second hydraulic cylinder is provided. The injection unit is rotatably supported by a moving table on which the injection unit is mounted, and the fixed mold and the block and the injection unit can be connected or separated from each other by expanding and contracting the piston rod of the second hydraulic cylinder. Regarding the injection unit, a hook is arranged on the front outer periphery of the heating cylinder, and a locking member is arranged at a position rearward of the outer circumference of the heating cylinder, which is slightly separated from the hook, so that the block and the locking member are engaged when the injection unit retracts. The block and the injection unit are combined together, and when the injection unit moves forward, the combination of the block and the locking member is released to release the block and the injection unit. Multicolor injection molding apparatus being characterized in that the possible disengagement configuration and a knit.