JP3003124B2 - Molding equipment for molding - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a molding apparatus for molding plastics.

[0002]

2. Description of the Related Art An example of a conventional molding die apparatus is described below.
This will be described with reference to FIG. In addition, this mold device
This is a valve gate type hot runner mold. 1 is a fixed type, 2 is a movable type, these fixed type 1 and movable type 2 are:
They move upward and downward in the figure to open and close, and form a product-shaped cavity 3 inside when the mold is clamped. In addition,
A plurality of cavities 3 are formed for multi-cavity production. The fixed mold 2 includes a fixed mold plate 4, a first fixed-side receiving plate 5 fixed to a back surface (an upper surface in the drawing) of the fixed mold plate 4, and a back surface of the first fixed-side receiving plate 5. And a fixed-side mounting plate fixed to the rear surface of the second fixed-side receiving plate 6 via a spacer block 7 and mounted on a fixed-side platen of an injection molding machine. 8 and
A manifold 9 is provided between the second fixed-side receiving plate 6 and the fixed-side mounting plate 8. The fixed mold plate 4 is formed by fitting a plurality of cavity members 12 forming an outer surface of a product into a frame plate 11, and these cavity members 12 have gates 13 that open to the respective cavities 3. Gate bushings 14 are embedded and fixed, respectively. A locating ring 16 is fixed to the outer surface of the fixed side mounting plate 8, and a sprue bush 17 to which a nozzle of an injection molding machine is connected is located on the inner peripheral side of the locating ring 16. Are fixed through. The sprue bush 17 has a sprue 18 inside and a heater 19 on the outer peripheral surface. The lower end in the figure of the sprue bush 17 is connected to the manifold 9. A runner 21 communicating with the sprue 18 is formed in the manifold 9. The manifold 9 has a built-in heater 22 and a heat insulating layer 23 on the outer surface. The fixed-side mounting plate 8 and the second fixed-side receiving plate 6
A plurality of spacers 24 are interposed between the and the manifold 9. Further, the fixed-side receiving plates 5 and 6 include:
A plurality of cylindrical valve casings 26 are fixed in a penetrating state. In these valve casings 26, the lower end in the figure is fitted in the gate bush 14, and
The illustrated upper end surface is joined to the lower surface of the manifold 9. The final branch of the runner 21 of the manifold 9 communicates with each of the valve casings 26. At the same time, in each of the valve casings 26,
A pin-shaped valve 27 for opening and closing the gate 13 of the gate bush 14 is supported so as to be movable in the vertical direction in the figure. In the upper part of the valve casing 26 in the figure, a guide bush 28 fixed in a fitted state is provided.
Is slidably penetrated. Further, each valve 27 is connected to a plurality of hydraulic or pneumatic cylinder devices 30 provided on the fixed-side mounting plate 8 through through holes 29 formed in the manifold 9 in the vertical direction in the figure. It is driven by the cylinder device 30.

On the other hand, the movable mold 2 includes a movable mold plate 31 and
A movable-side receiving plate 32 attached to the back surface (the lower surface in the figure) of the movable-side mold plate 31, and a movable-side platen of an injection molding machine attached to the back surface of the movable-side receiving plate 32 via a spacer block 33 and a support 34. Movable side mounting plate mounted on
35 and has. The movable mold plate 31 is disposed in a frame plate 36,
A core member 37 forming the inner surface of the product;
Are fitted with a base plate 38 that supports the lower part of the drawing from below.
At the same time, a slide core 39 for forming an undercut-shaped part of a product is supported on the movable mold plate 31 so as to be movable in the horizontal direction in the figure. These slide cores 39
Moves horizontally in the figure as the fixed mold 1 and the movable mold 2 are opened and closed by the angular pins 40 fixed to the fixed mold plate 4. A projecting plate 41 is supported between the movable receiving plate 32 and the movable mounting plate 35 so as to be relatively vertically movable in the drawing. A plurality of protrusion pins 42 are fixed to the protrusion plate 41. These protruding pins 42 are connected to the movable receiving plate 32 and the movable mold plate.
31 slidably penetrates in the vertical direction in the figure, and the front end faces the cavity 3.

Next, the structure of the gate bush 14 and the valve casing 26 will be described in more detail with reference to FIG. In FIG. 3, 12a is the cavity member 1
2, a cavity forming surface, 37a is a cavity forming surface of the core member 37, and 39a is a cavity forming surface of the slide core 39. Although the gate bush 14 has a substantially cylindrical shape, a tapered portion 51 is formed so as to protrude at the center of the lower surface, and a gate is formed at the tip of the tapered portion 51 exposed on the cavity forming surface 12a of the cavity member 12. Has 13 In the conventional mold apparatus, the gate bush 14 is formed in the cavity member 12 and the gate bush is formed.
The first cavity member 12 and the first cavity member 12 fitted in the fitting hole 52 having the same shape as the outer surface of
Are fixed to the cavity member 12 by being sandwiched by the fixed-side receiving plate 5. Further, between the cavity member 12 and the gate bush 14, a cooling fluid passage 53 is formed by a concave groove formed on the outer peripheral surface of the gate bush 14, and the cooling fluid passage 53 is formed. Sandwich it,
A pair of rubber O-rings 54 and 55 are provided. The cooling fluid passage 53 communicates from the cavity member 12 to a cooling fluid passage 56 formed in the fixed-side receiving plate 5. These cooling fluid passages 56 are open to the outside of the fixed mold 1, and water as a cooling fluid flows through hoses connected to the openings. The valve casing 26 has a band heater 62 on the outer peripheral surface of the inner cylinder 61.
Are wound, and the band heater 62 is covered by a cylindrical heater cover 63 from the outer peripheral side. Further, an outer cylinder 64 is provided on the outer peripheral side of the heater cover 63. A valve holder 65 is fitted into the lower part of the inner cylinder 61 in the figure, and a cylindrical presser 66 for pressing and fixing the valve holder 65 from below is screwed into the inner cylinder 61. The lower part of the valve 27 is slidably held by a valve holder 65.

Next, the operation of the above configuration will be described. At the time of molding, after the fixed mold 1 and the movable mold 2 are clamped, the valve 27 is raised as shown in the figure, and molten resin is injected from the nozzle of the injection molding machine. This molten resin passes through the sprue 18, the runner 21 in the manifold 9 and the valve casing 26 sequentially, and
14 flows into the cavity 3 formed between the fixed mold 1 and the movable mold 2 from the opened gate 13. After the filling of the cavity 3 with the resin is completed, the valve 27 is lowered in the figure, and the distal end of the valve 27 is fitted to the gate 13, and the gate 13 is closed. After the resin in the cavity 3 is cooled and solidified, the fixed mold 1 and the movable mold 2 are opened. With the opening of the mold, first, the product which is the resin solidified in the cavity 3 separates from the movable mold 2 and the slide core 39 separates from the product. Next, the protruding plate 41 is pushed by the protruding rod of the injection molding machine, and the protruding plate 41 rises relative to the movable mold plate 31 in the figure. Then, the product is protruded by the protruding pin 42 that rises together with the protruding plate 41, separated from the movable mold 2, and taken out. By the way, the sprue bush 17
Is heated, the heater 22 heats the manifold 9, and the heater 62 heats the valve casing 26, so that the sprue 18, the runner 21 and the resin in the valve casing 26 are always kept in a molten state. Thereby, the molding efficiency is increased. Gate by valve 27 when mold is opened
The reason why the block 13 is closed is to prevent the resin from leaking from the gate 13 except when filling the cavity 3 with the resin. Thus, while the resin in the sprue 18, the runner 21, and the valve casing 26 is heated, the resin in the cavity 3 must be cooled. Therefore, water is caused to flow through cooling fluid passages 53 and 56 including those not shown around the cavity 3 to cool the vicinity of the cavity 3. In particular, the water passing through the cooling fluid passage 53 between the gate bush 14 and the cavity member 12 cools the gate bush 14 and the cavity member 12 around the valve casing 26 heated by the heater 62. That is, the gate bush 14 to which heat is transmitted from the valve casing 26 is actively cooled by water passing through the cooling fluid passage 53 on the outer periphery thereof, so that the temperature difference between the gate bush 14 and the cavity member 12 is reduced. . The reason why the gate bush 14 is provided separately from the cavity member 12 is to achieve both workability in manufacturing a mold and wear resistance of the gate 13 on which the valve 27 slides. That is, while the cavity member 12 is made of a relatively soft metal material such as HPM,
Is made of a hard metal material such as SKH.

[0006]

As described above, in the conventional molding apparatus, the gate bush 14 is simply fitted into the fitting hole 52 formed in the cavity member 12 and fixed to each other by bolts. The gate bush 14 and the cavity member 12, which are sandwiched and fixed between the cavity member 12 and the first fixed-side receiving plate 5, and have a cooling fluid passage 53 on the outer periphery.
O-rings 54 and 55 made of rubber are provided between the gate bush 14 and the cavity member 12 in order to maintain liquid tightness between the gate bush 14 and the cavity member 12.
The use of the rubber O-rings 54 and 55 has a problem in durability. Therefore, it is conceivable to weld the gate bush 14 to the cavity member 12 without using the rubber O-rings 54 and 55 in order to obtain sufficient liquid tightness. Is difficult to obtain, which is not preferable.

SUMMARY OF THE INVENTION The present invention is intended to solve such a problem, and it is possible to reliably maintain liquid tightness between a gate bush and a cavity member in which a cooling fluid passage is provided on the outer periphery, and to improve durability. An object of the present invention is to provide a molding die apparatus which is excellent and has sufficient dimensional accuracy in production.

[0008]

In order to achieve the above object, the present invention comprises a fixed mold and a movable mold which can be freely opened and closed and have a cavity formed therein during mold clamping.
A cavity member having a cavity forming surface; and a gate bush having a substantially cylindrical shape having a tapered portion on the distal end side and having a gate opening to the cavity at the distal end portion of the tapered portion, and forming the gate bush on the cavity member. While fitting into the fitting hole
In a molding die apparatus in which a cooling fluid passage is formed between the inner peripheral surface of the fitting hole of the cavity member and the outer peripheral surface of the gate bush, the cavity member and the gate bush are fixed to each other by diffusion bonding. Things.

[0009]

In the molding die apparatus of the present invention, at the time of molding, the fixed mold and the movable mold are clamped to form a cavity between the fixed mold and the movable mold. The resin is poured into the cavity from the gate of the gate bush embedded in the cavity. At this time, the cooling fluid flows through the cooling fluid passage between the cavity member and the gate bush to cool the gate bush and the cavity member. Then, after the resin filled in the cavity is solidified, the fixed mold and the movable mold are opened, and a product that is the resin solidified in the cavity is taken out. By the way, in manufacturing, the cavity member and the gate bush are fixed to each other by diffusion bonding, but this ensures that the liquid tightness between the gate bush and the cavity member having the cooling fluid passage on the outer periphery is maintained. . Moreover, since the gate bush has a tapered portion, the cavity member and the gate bush can be reliably positioned during diffusion bonding,
Joining can be performed more reliably. In addition, since it is not necessary to use a rubber O-ring or the like for maintaining liquid tightness, durability is improved.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the molding apparatus according to the present invention will be described below with reference to FIG. The molding die apparatus of this embodiment is common in many respects to the conventional die apparatus shown in FIGS. 2 and 3, and the common parts are denoted by the same reference numerals and the description thereof will be omitted. The description is omitted, and different points are mainly described. In this embodiment, the gate bush 71 is fitted in the fitting hole 52 formed in the cavity member 12, and is fixed to the cavity member 12 by diffusion bonding (diffusion welding). The materials of the cavity member 12 and the gate bush 71 are the same as those of the related art. Then, when diffusion bonding the cavity member 12 and the gate bush 71, the gate bush 71 is fitted into the fitting hole 52 of the cavity member 12, and the gate bush 71 and the cavity member 12 are pressurized by an appropriate jig. After fixing, it is heated, for example, in a furnace. As a result, the metal atoms of the material of the gate bush 71 and the material of the cavity member 12 are mutually diffused, and the gate bush 71 and the cavity member 12 are joined. At this time, it is necessary to add an auxiliary agent to activate. During the diffusion bonding, quenching is performed at the same time. In this embodiment, no other member such as a rubber O-ring is provided between the cavity member 12 and the gate bush 71.

As described above, in this embodiment, since the cavity member 12 and the gate bush 71 are fixed to each other by diffusion bonding, the cavity member 12 and the gate bush 71 are fixed.
And the cooling fluid passage 53 can reliably maintain liquid tightness between the gate bush 71 and the cavity member 12 on the outer periphery, and can prevent water leakage outside the cooling fluid passage 53 during molding. . In addition, the tapered portion 51 is provided at the tip end side of the gate bush 71, so that the cavity member 12 and the gate bush 71 are joined not only in the radial direction but also in the axial direction.
At the time of diffusion bonding with 71, the positioning of the cavity member 12 and the gate bush 71 can be reliably performed, and bonding can be performed more reliably. In addition, since no rubber O-ring or the like is used for maintaining liquid tightness, durability is improved. Furthermore, compared to the case where the cavity member and the gate bush are welded by, for example, arc welding,
Sufficient dimensional accuracy can be obtained.

Note that the present invention is not limited to the above-described embodiment, and various modifications can be made. For example,
Of course, the configuration of the entire mold is not limited to the one shown in FIG. 2, and the shape of the gate bush 71 is not limited to that shown in the figure.

[0013]

According to the present invention, there is provided a gate bush having a substantially cylindrical shape and having a tapered portion on the distal end side. The gate bush is fitted into a fitting hole formed in the cavity member, and the gate bush is formed. In the molding die apparatus in which the cooling fluid passage is formed between the inner peripheral surface of the fitting hole and the outer peripheral surface of the gate bush, the cavity member and the gate bush are fixed to each other by diffusion bonding. Despite the fact that a cooling fluid passage is formed between the inner peripheral surface of the fitting hole and the outer peripheral surface of the gate bush,
The cavity member and the gate bush can be securely joined, the liquid tightness between the cavity member and the gate bush can be reliably maintained, and leakage of the cooling fluid from the cooling fluid passage during molding can be reliably prevented, In addition, since it is not necessary to use a rubber O-ring or the like for maintaining liquid tightness, durability is improved, and further, for example, compared to a case where the cavity member and the gate bush are welded by arc welding. In production, sufficient dimensional accuracy can be obtained.

[Brief description of the drawings]

FIG. 1 is a sectional view of the vicinity of a gate bush showing one embodiment of a molding die apparatus of the present invention.

FIG. 2 is a cross-sectional view showing an example of a conventional molding die apparatus.

FIG. 3 is an enlarged sectional view showing the vicinity of a gate bush according to the first embodiment;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Fixed type 2 Movable type 3 Cavity 12 Cavity member 12a Cavity forming surface 13 Gate 51 Taper part 52 Fitting hole 53 Cooling fluid passage 71 Gate bush

Continuation of front page (56) References JP-A-63-40688 (JP, A) JP-A-3-83617 (JP, A) JP-A-2-292005 (JP, A) JP-A-63-246221 (JP) , A) (58) Field surveyed (Int. Cl. ⁷ , DB name) B29C 45/26-45/44 B29C 33/00-33/76 B29C 45/73

Claims (1)

(57) [Claims] 1. A fixed mold and a movable mold, which are freely openable and closable and have a cavity formed therein at the time of mold clamping.
A cavity member having a cavity forming surface; and a gate bush having a substantially cylindrical shape having a tapered portion on the distal end side and having a gate opening to the cavity at the distal end portion of the tapered portion, and forming the gate bush on the cavity member. While fitting into the fitting hole
In a molding die apparatus in which a cooling fluid passage is formed between the inner peripheral surface of the fitting hole of the cavity member and the outer peripheral surface of the gate bush, the cavity member and the gate bush are fixed to each other by diffusion bonding. A molding die apparatus characterized by the above-mentioned.