JP2003154548A - Cassette type hot runner mold - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cassette type hot runner mold in which a cassette mold and a hot runner cassette can be simply attached to and detached from a matrix without removing the matrix from a molding machine, which can easily deal with changing of the molding and changing of a molding resin, and reductions in a cost and a molding cycle time can be realized. SOLUTION: The cassette type hot runner mold comprises a matrix 1, the hot runner cassette 2 detachably engaged with the matrix 1 from the direction crossed with a resin channel, a cassette mold 3 detachably mounted at the matrix 1 at the resin discharge side of the cassette 2, and a locking means 4 for locking the mold 3 to the matrix 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cassette type hot runner die for injection molding.

[0002]

2. Description of the Related Art Conventionally, a hot runner provided on a mother die and a clearance set between the tip of the cassette die and the tip of the hot runner have been provided. A cassette type hot runner mold composed of a large member is disclosed in Japanese Patent Laid-Open No. 52203/1995.
It is disclosed in Japanese Patent Publication No. According to this, when the hot runner is heated, the tip of the tip comes into contact with the cassette mold due to thermal expansion, so continuous molding is possible, and when there is no heating, there is a clearance so that the cassette mold can be easily attached and detached, and the mold manufacturing cost can be reduced. It can be reduced. However, in this product, the manifold that constitutes the hot runner is fixed to the mother die with bolts from the molding machine fixing side, so the mother die must be removed from the molding machine in order to attach and detach the manifold. Therefore, it is troublesome to attach / detach the manifold to / from the mother mold at the time of replacement of consumable parts and cleaning accompanying the change of resin, which hinders shortening of the molding cycle.

[0003]

SUMMARY OF THE INVENTION According to the present invention, the cassette mold and the hot runner cassette can be easily attached to and detached from the mother die without removing the mother die from the molding machine, and it is possible to easily cope with the change of the molding resin. An object of the present invention is to provide a cassette type hot runner die capable of lowering the molding temperature and shortening the molding cycle.

[0004]

A cassette type hot runner die of the present invention comprises a mother die, a hot runner cassette detachably fitted to the mother die in a direction intersecting with a resin flow path, and the hot runner cassette. A cassette type detachably attached to the mother die on the resin discharge side of the runner cassette,
Locking means for locking the cassette mold to the mother mold. When changing the molding resin or replacing the parts of the hot runner cassette, after removing the hot runner cassette from the mold and cleaning the resin flow path, etc., with the mother mold attached to the molding machine. , Re-incorporate into the mold.

The hot runner cassette has a runner block removably positioned and fitted in the mother die, a bush block removably attached to the runner block, and a runner block attached to the runner block.
A runner bush penetrating this and a sprue bush attached to the bush block and penetrating this are provided, and a resin flow path is formed through the sprue bush and the runner bush, and the sprue bush and the runner bush are formed. A heater for heating the resin flow path is provided. With this configuration, the entire hot runner cassette can be easily and accurately attached / detached to / from the mother die simply by disengaging the runner block from the mother die.
Further, when the runner block and the bush block are separated, the runner bush and the sprue bush are also separated, and as a result, the resin flow path is divided, which facilitates cleaning.

The locking means has a clamp for pressing the cassette mold against the hot runner cassette and releasing the pressing force by operating the operation lever. As a result, the cassette type and the hot runner cassette can be easily attached and detached by operating the operation lever. The cassette type may have a flat tip surface and need not be replaced depending on the molded product.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below in detail with reference to the drawings. In the cassette type hot runner mold of the present invention, since the moving side half has a structure similar to that of the conventional one, only the fixed side half will be described below. As shown in FIGS. 1 and 2, the cassette type hot runner mold includes a mother die 1 attached to a molding machine (not shown), a hot runner cassette 2 detachably fitted to the mother die 1, and a hot runner. A cassette mold 3 is detachably attached to the mother mold 1 on the resin discharge side of the cassette 2, and a locking unit 4 for locking the cassette mold 3 to the mother mold 1.

The mother die 1 has a mating recess 5 for mounting the hot runner cassette 2 and the cassette die 3 therein.
Is formed so as to open on the front surface (the surface facing the moving side half), the rear surface (the surface on the side where the molding machine is mounted) and one side surface, and the mother die 1 is mounted on the molding machine at the rear end of the mother die 1. A locate ring 6 for mounting is mounted along the opening of the fitting recess 5. A first ball plunger 7 for positioning the hot runner cassette 2 is mounted on the inner peripheral surface of the fitting recess 5. Further, a lid 8 is provided on the front surface of the mother die 1. The lid 8 is narrower than the width of the fitting recess 5,
A cutout groove 9 that is slightly wider than the width of the cassette mold 3 is formed so that the same side surface as the fitting recess 5 opens. Further, a screw hole 10 for attaching the locking means 4 is formed in the lid body 8 close to the notch groove 9.

As shown in FIGS. 3 and 4, the hot runner cassette 2 is designed to be taken in and out of the fitting concave portion 5 of the mother die 1 through one side face which is open.
Runner block 11 that is removably positioned and fitted to the runner block 11.
And a bush block 12 detachably attached to the runner block 11 on the molding machine attachment side, a runner bush 13 attached to the runner block 11 and penetrating it, and a bush block 12 attached to the bush block 12 and penetrating it. And a sprue bush 14 that

The runner block 11 is inserted near the lid 8 of the fitting recess 5, and a recess 15 for engaging with the ball portion of the first ball plunger 7 is formed on the outer peripheral surface thereof.
In addition, the runner block 11 includes a runner bush 1
A fitting hole 16 for inserting 3 is formed along the central axis. An end portion of the fitting hole 16 near the bush block 12 is a large-diameter concentric circular step portion 17. further,
A second ball plunger 18 protruding into the cutout groove 9 of the lid 8 is attached to the end surface of the runner block 11. A pull-out lever 41 used when taking out the hot runner cassette 2 is attached to one side surface of the runner block 11.

The bush block 12 is fitted to the fitting recess 5 near the locate ring 6 and is fitted to the runner block 11.
A through hole 19 for inserting the sprue bush 14 and a second heater 29 described later is formed along the central axis thereof. Runner bush 13
Penetrates through the fitting hole 16 of the runner block 11 and projects from the end face thereof. The end portion of the runner bush 13 near the bush block 12 is engaged with the step portion 17 of the runner block 11. As a result, the large-diameter stepped portion 20 that prevents it from coming off is projected.

The runner bush 13 is provided with a downstream resin flow passage 21 along its central axis. The resin inflow side end portion of the downstream side resin flow path 21 has a slightly large diameter.
Further, the first heater 22 is inserted inside the downstream resin flow path 21 of the runner bush 13. The portion of the first heater 22 excluding the resin inflow side end portion has a smaller diameter than the downstream resin flow passage 21, and the inner peripheral surface of the downstream resin flow passage 21 and the outer peripheral surface of the first heater 22 are A gap 21 'through which the molten resin flows is formed therebetween. The tip of the first heater 22 projects from the end surface of the runner bush 13 and is tapered.

Further, the resin inflow side end portion of the first heater 22 has a slightly large diameter so as to be fitted and positioned with the large diameter portion of the downstream side resin flow passage 21, and both sides of this portion. A branch flow path 23 communicating with the gap 21 ′ is formed therein. Then, the copper ring 24 is fitted so as to cover the outer circumference of the large-diameter portion provided at the resin inflow side end of the first heater 22.

The sprue bush 14 has a pipe portion 25 which is inserted into the insertion hole 19 of the bush block 12, and a flange 26 which abuts on the end face of the bush block 12 on the side of the molding machine mounting side. An upstream resin flow channel 27 is formed along the central axis through 26. A dish-shaped recess 28 that engages with the nozzle of the molding machine is formed at the base end of the upstream resin flow path 27.

A second heater 29 is provided on the outer peripheral surface of the tube portion 25.
Is externally fitted, and the flange 26 is provided with a temperature sensor 30. The temperature sensor 30 is connected to a temperature control device (not shown), and the temperature control device controls ON / OFF of the chip heater built in the tip portion of the first heater 22 to control the upstream resin flow path 27 and the branch flow path. 23 and the flow of the molten resin in the downstream resin flow passage 21 (gap 21 ') are controlled.

Then, the sprue bush 14 inserted into the insertion hole 19 together with the second heater 29 is attached to the bush block 12 by bolting. Further, when the bush block 12 and the runner block 11 are fixed with bolts, the upstream resin flow passage 27 of the sprue bush 14 and the downstream resin flow passage 21 of the runner bush 13 coincide with each other. The cord 40 extending from the first heater 22 and the second heater 29 is drawn out through the mother die 1 in a direction intersecting with the upstream resin flow path 27 and connected to an external power source.

The hot runner cassette 2 assembled in this manner has one side surface opened from the direction intersecting the upstream resin flow path 27 and the downstream resin flow path 21 even when the mother die 1 is fixed to the molding machine. It can be easily put in and taken out from the fitting concave portion 5 through. Also, runner block 11
The entire hot runner cassette 2 is positioned with respect to the mother die 1 by engaging the concave portion 15 with the first ball plunger 7 protruding from the inner peripheral surface of the fitting concave portion 5.

The cassette mold 3 shown in the drawing is a fixed-side mold plate, and its rear end face (end face on the hot runner cassette 2 side).
A locking recess 31 that engages with the ball portion of the second ball plunger 18 built in the runner block 11 is formed in the. In addition, on the outer periphery of the front end of the cassette mold 3,
An engagement step portion 32 for locking the locking means 4 is formed so as to be flush with the front end surface of the lid body 8. Further, the cassette die 3 is formed with a fitting hole 33 that fits with the front end portion of the runner bush 13 along the central axis. A portion of the fitting hole 33 beyond the runner bush 13 has an upstream inner diameter that is substantially the same as the inner diameter of the downstream resin flow path 21 and forms a tapered reservoir portion 34. The tip portion is inserted into this reservoir portion 34.

As shown in FIGS. 1 and 5, the locking means 4 has a substantially U-shaped clamp 3 whose both ends are bent toward the lid 8.
5, a coil spring 36 interposed between the front surface of the lid body 8 and the clamp 35 to urge the clamp 35 in a direction away from the lid body 8 and a central portion of the clamp 35 and the coil spring 36. A bolt 37 screwed into the screw hole 10 of the lid 8 and an operation lever 38 having one end fixed to the head of the bolt 37 by a knock bolt 42. A large-diameter circular hole is formed on the surface side of the screw hole 10, and a half portion of the coil spring 36 is inserted into this circular hole. Further, when the cassette die 3 is locked to the mother die 1, one end of the clamp 35 abuts on the front surface of the lid body 8 and the other end abuts on the cassette die 3.

The operation lever 38 is rotated to operate the bolt 37.
And the clamp 35 is pushed by the coil spring 36 and lifted from the lid 8, the cassette mold 3
The hot runner cassette 2 and the hot runner cassette 2 assembled thereto can be taken in and out of the cutout groove 9 and the fitting recess 5 of the mother die 1 in a direction intersecting with the downstream resin flow passage 21 and the upstream resin flow passage 27. Then, the operating lever 38 is rotated in the reverse direction to tighten the bolt 37, whereby the clamp 35 is brought closer to the lid body 8 against the biasing force of the coil spring 36, and both ends of the clamp 35 are brought into the lid body 8 and the cassette type, respectively. When pressed against the engagement step portion 32 of 3, the cassette mold 3 and the hot runner cassette 2 are attached to the mother mold 1.

Further, when the clamp 35 is rotated so as to be retracted from the cutout groove 9 of the lid body 8 in a state where the bolt 37 is loosened and the clamp 35 is lifted from the lid body 8, the hot runner cassette 2 is moved to the mother die 1. Only the cassette die 3 can be taken in and out from the front surface where the notch groove 9 is opened, while being assembled. Then, after the cassette mold 3 is fitted into the notch groove 9 and the locking recess 31 is engaged with the second ball plunger 18 of the runner block 11 to be positioned,
One end is the lid 8, and the other end is the engagement step 3 of the cassette mold 3.
When the clamps 35 are rotated so as to face each other, and then the bolts 37 are tightened to bring the clamps 35 close to the lid body 8, the cassette mold 3 becomes the hot runner cassette 2
It is pressed against and is fixed to the mother die 1.

In order to perform molding, first, the mother die 1 is attached to the molding machine via the locate ring 6, and then the hot runner cassette 2 and the cassette die 3 assembled in advance are fitted into the mother die 1 with the fitting recesses 5 and the notches. The groove 9 is incorporated from the side. Then, after engaging and positioning the first ball plunger 7 of the mother die 1 and the recess 15 of the runner block 11, the cassette die 3 and the hot runner cassette 2 are fixed to the mother die 1 by the locking means 4. Then, the moving side mold (not shown) is brought close to the first heater 22 and the second heater 29 to be energized.

Upstream resin flow path 27 and downstream resin flow path 2
When the temperature of No. 1 reaches a desired temperature, molten resin is injected into the dish-shaped recess 28 of the sprue bush 14 from the nozzle of the molding machine.
The injected molten resin flows from the upstream resin flow passage 27 of the sprue bush 14 into the branch flow passage 23 of the first heater 22, and the inner peripheral surface of the downstream resin flow passage 21 and the first heater 22 are separated from each other. After passing through the gap 21 ′ formed between them, they are accumulated in the accumulating portion 34 of the cassette mold 3 and are injected into the cassette mold 3 to be molded.

When the molding of the same type of molded product is completed, the energization of the first heater 22 and the second heater 29 is stopped, the clamp 35 of the locking means 4 is rotated, and the cutout groove 9 of the lid 8 is formed. Then, the cassette mold 3 is pulled out to the front of the cutout groove 9 and removed from the mother mold 1. When another molded product is produced using the same resin, a cassette mold corresponding to this molded product is selected and inserted from the front surface of the notch groove 9,
The locking recess 31 and the second ball plunger 18 are engaged with each other, and the bolt 37 of the locking means 4 is further tightened to attach the cassette mold 3 to the mother mold 1.

When changing the resin, the hot runner cassette 2 and the cassette die 3 are pulled out laterally from the fitting recess 5 and the notch 9 of the mother die 1. Then, the runner block 11 and the bush block 12 of the hot runner cassette 2 are disassembled to separate the runner bush 13 and the sprue bush 14. Further, the upstream resin flow passage 27, the branch flow passage 23, and the downstream resin flow passage 21 (the gap 2
After cleaning 1 '), the runner block 11 and the bush block 12 are assembled, the hot runner cassette 2 and the optional cassette mold 3 are assembled into the mother mold 1 from the side and locked by the locking means 4. In the hot runner mold of the present invention, a cavity may be provided in the moving-side cassette mold, and the stationary-side cassette mold 3 may be a flat mold whose tip surface is smooth and which does not need to be replaced by a molded product.

[0026]

According to the invention of claim 1, the cassette die and the hot runner cassette can be easily attached to and detached from the mother die with the mother die attached to the molding machine.
It is easy to change the cassette mold when changing the molded product, clean the resin flow path when changing the molding resin, and replace consumable parts.As a result, setup efficiency is improved and high-mix low-volume production is possible. In addition, cost reduction and molding cycle reduction can be realized.

According to the second aspect of the present invention, by positioning and fitting the runner block in the mother die, the entire hot runner cassette can be easily and accurately incorporated in the correct position. Moreover, when the runner block and the bush block are separated, the resin flow path is divided,
Easy to clean resin flow path. According to the invention of claim 3, the cassette type can be easily exchanged by only operating the operation lever.

[Brief description of drawings]

FIG. 1 is a sectional view of a cassette-type hot runner die showing an embodiment of the present invention.

FIG. 2 is a perspective view of the above.

[Figure 3] Cross-sectional view of the hot runner cassette

[Fig. 4] Exploded sectional view of the hot runner cassette

FIG. 5 is an exploded side view of the locking means.

[Explanation of symbols]

1 mother pattern 2 hot runner cassette 3 cassette types 4 Locking means 5 Fitting recess 6 Locate ring 7 First Ball Plunger 8 lid 9 Notch groove 10 screw holes 11 runner block 12 Bush block 13 Runner bush 14 Sprue Bush 15 recess 16 fitting holes 17 steps 18 Second Ball Plunger 19 insertion holes 20 Large diameter step 21 Downstream resin flow path 21 'gap 22 First heater 23 branch channels 24 copper ring 25 pipe section 26 Flange 27 Upstream resin flow path 28 Plate-shaped recess 29 Second heater 30 temperature sensor 31 Locking recess 32 engagement step 33 Fitting hole 34 Pool 35 clamp 36 coil spring 37 Volts 38 Control lever 40 code 41 Extraction lever 42 knock bolt

Claims (4)

[Claims] 1. A mother die, a hot runner cassette removably fitted to the mother die from a direction intersecting with a resin flow path, and a resin discharge side of the hot runner cassette detachably attached to the mother die. A cassette-type hot runner mold, comprising: a cassette mold and a locking means for locking the cassette mold to the mother mold. 2. The hot runner cassette has a runner block removably positioned and fitted to the mother die, a bush block removably attached to the runner block, and a runner block attached to the runner block. And a sprue bush that is attached to the bush block and penetrates the bush block, and a resin flow path is formed through the sprue bush and the runner bush. The cassette type hot runner die according to claim 1, further comprising a heater for heating the resin flow path. 3. The cassette type hot runner metal according to claim 1, wherein the locking means has a clamp for pressing the cassette die against the hot runner cassette and releasing the pressing force by operating an operating lever. Type. 4. The cassette type hot runner mold according to claim 1, wherein the cassette mold has a smooth end surface and does not need to be replaced depending on a molded product.