JP3383362B2 - Hot runner type synthetic resin mold heater pot - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heater pot incorporated in a synthetic resin hot runner type injection molding die.

[0002]

2. Description of the Related Art In recent years, as means for molding synthetic resin products,
A heater pot for heating and supplying molten resin (also referred to as a heater cast) is continuously provided at the tip of the runner, and a heater pot A is provided at the tip of the runner R as shown in FIG. Hot runner type molds (also called valve gate type) for direct filling have been used. This hot runner type mold is suitable for molding synthetic resin products with an extremely thin wall and for molding synthetic resin products with limited gate positions. (For example, Japanese Patent Laid-Open No. 2-24110)

As shown in FIG. 6, the heater pot has a pot body B having a resin passage J formed in the center thereof, a valve pin V inserted into the resin passage J of the pot body B, and a valve pin V having a resin passage J.
A body G which is composed of a piston P which moves up and down toward a nozzle N provided in the lower part of the pot, and a heater H which heats the pot body B, and the pot body B further has a resin passage J formed therein,
It is composed of a collar body F that fits outside the upper part of the body G, and a pin guide body E that fits in the upper part of the resin path J. The molten resin is heated to directly fill the cavity C.

The body G which constitutes the pot body B has a guide passage K which is communicated with the resin passage J from the outside at a slight inclination, and a collar body F which fits on the outer side of the upper portion of the body G has an outer diameter. D1 is formed to have a diameter approximately three times larger than the outer diameter d of the main body b, and the collar body F
A guide hole L communicating with the guide path K of the runner R and the body G is formed by bending from the upper surface to the inner circumference. The pin guide body E is provided with a tapered conical portion e at the lower portion, and a pin insertion hole Q is provided at the center thereof.
Has been drilled.

[0005]

A conventional heater pot is provided with an inclined guide passage communicating with a resin passage at an upper portion of a pot body, a collar body is fitted to an outer side of an upper portion of the body, and the collar body is guided with a runner. Since the guide hole that communicates with the road is formed, there is a problem that a high degree of skill is required for forming the guide hole, and there is a problem that a misalignment easily occurs between the guide path and the guide hole. There is also a problem that the outer diameter of the pot body is increased due to the fitting of the collar body, and the heater pot arrangement interval must be widened.

Since the lower portion of the pin guide body is formed in a tapered conical portion in accordance with the inclination of the guide path, the molten resin penetrates to the base portion of the conical portion, and the residual solid layer remains at the base portion of the conical portion. Install. As a result, when removing this residual solid layer, there is a problem that removal is difficult and requires a high degree of skill. The present invention has been made in view of the above problems of the prior art, and an object of the present invention is to easily remove the residual solidified layer and to arrange the heater at a small interval. To serve the pot.

[0007]

In order to achieve the above object, the heater pot of the hot runner type synthetic resin mold of the present invention comprises a pot body for directly feeding a molten resin into a cavity, and a resin passage in the center. It is composed of the body provided and a lid mounted on the body, a guide path continuous with the resin path is provided at the upper part of the body, and a valve pin guide part is provided at the center of the cover disk part, and the tip of the guide part is provided. Part is formed on an inclined surface along the guideway of the body, and a guide groove communicating with the guideway is formed on the sloped surface, and a guide hole continuous with the runner and the guideway is formed on the outer periphery of the lid. It is a thing.

[0008]

EXAMPLE First, FIG. 1 shows the structure of a fixed mold in injection molding.
Based on the description, the fixed mold 20 is composed of at least a first plate 21, a second plate 22, and a mounting plate 23,
A runner R is continuously bored on the spool S, the heater pot 1 of the present invention is attached to the tip of the runner R, and a cavity C is provided at a joint between the first plate 21 and a movable mold (not shown).
And the molten resin is directly fed from the heater pot 1 to the cavity C.

Next, the structure of the heater pot according to the present invention will be described with reference to FIGS. 2 to 4. The heater pot 1 has a pot body 2 having a resin passage 4 at its center, and the body 2.
Body 3 having a valve pin 9 to be inserted into the valve body, a piston P for moving the valve pin 9 up and down, and a heater H for heating the pot body 2. It is composed of a lid 6 mounted on the top.

The body 3 forming the pot body 2 has a collar portion 3b, which is approximately twice as large as the outer diameter d of the body portion, on the upper portion of the cylindrical body portion 3a.
A resin passage 4 is formed in the center of the body 3 from the top to the bottom, and the nozzle 14 is provided at the lower end of the resin passage 4, and the flange 3b is provided with resin from the upper end of the body 3. A guide path 5 having an inclination angle θ that is inclined downward toward the path 4 is provided, and a heater insertion hole 12 is provided in the outer peripheral portion of the body 3a.
The smaller the inclination angle θ is, the smaller the size becomes, but 70 to 80 degrees is desirable.

As shown in FIG. 3, the lid 6 is provided with a guide portion 7 for the valve pin 9 at the center of the disc portion 6a, and the tip of the guide portion 7 is formed on the inclined surface 7a along the guide path 5 of the body 3. Then, a guide groove 17 communicating with the guide path 5 and intersecting with the resin path 4 is provided on the inclined surface 7a,
A guide hole 8 continuous with the runner R and the body guiding path 5 is formed on the outer periphery of the disc portion 6a. The disc portion 6a is formed to have a size equal to the outer diameter D2 of the collar portion of the body 3 to guide the body. A notch 16 is formed in the outer peripheral portion of the disk portion 6a opposite to the position where the hole 8 is formed.

In the figure, 15 is a spool bush assembled on the inlet side of the fixed mold 20, 18 is a center pin fitted across the second plate 22 and the manifold 19, and 25 is a first plate 21 and a second plate. Auxiliary guide pin that fits over 22 and 26
Is a positioning block, 27 is a cooling water hole, 28 is a manifold 19
Set bolts for fixing, 29 is second plate 22 and mounting plate
It is a spacer block interposed between 23.

Since the heater pot of the present invention has the above-mentioned structure, for example, the inclination angle θ of the guide path 5 inclined from the upper surface of the body flange portion 3b toward the resin path 4 and the inclined surface of the lid guide portion 7 are provided. 7a are provided at 75 degrees with respect to the resin path 4, guide grooves 17 communicating with the guide path 5 are bored in the inclined surface 7a, and the disc portion of the lid body 6 is formed.
The guide hole 8 provided in 6a is vertically formed. Further, the heater insertion hole 12 provided in the body portion 3a is provided so as to penetrate deeper inside the outer surface of the body portion 3a.

When assembling the heater pot 1 of the present invention,
For example, the valve pin 9 is inserted into the guide portion 7 of the lid body 6, and the tip of the valve pin 9 is inserted into the resin passage 4 of the body 3,
After inserting the lid 6 onto the body 3 until it overlaps, the lid 6 is rotated, the guide hole 8 of the lid 6 and the guide path 5 of the body 3 are completely aligned, and the lid 6 is fixed to the body 3. By assembling and constructing, the flange outer diameter D2 and the pot body height t can be formed to approximately 2/3 of the body outer diameter D1 and the body height T of the conventional heater pot A, respectively.

The heater pot according to the present invention has a fixed mold 20.
As shown in FIG. 4 (B), when a synthetic resin product is molded in the same manner as in the prior art and a synthetic resin product is molded, a residual solidified layer m is formed along the inclined surface 7a of the lid guide portion 7 and the outer periphery of the resin passage 4 as shown in FIG. Adhere to. When removing the residual solidified layer m adhering to the guide path 5 of the heater pot 1, first, the valve pin 9 is pulled out from the heater pot 1, and the pot body 2 is separated into the body 3 and the lid body 6. The residual solidified layer m adhered to 7a and the resin passage 4 can be easily removed.

The heater pot according to the present invention is not limited to the above-mentioned embodiment. For example, the tapered valve portion 9a is provided at the tip of the valve pin 9 and the notch 16 is provided at the outer peripheral portion of the lid disc portion 6a. Can be provided on the drilling side of the guide hole 8. Further, the shape and structure of the body 3 and the lid 6 forming the pot body 2, the assembling means, and the like can be appropriately changed without departing from the spirit of the present invention.

[0017]

Since the heater pot of the present invention has the above structure, it has the following effects. By constructing the pot main body from the body and the lid mounted on the body, and by integrally providing the pin guide portion on the lid, it is possible to remarkably easily facilitate the formation of the guideway, the guide hole, etc. Misalignment of the guide holes does not occur. Moreover, since the outer diameter of the pot body and the height of the pot body can be reduced by about 30%, the heater pots can be arranged at small intervals to form a precise synthetic resin product.

Since the tip of the lid guide portion is formed on the inclined surface along the guide path of the body, and the guide groove communicating with the guide path is bored on the inclined surface, it remains in the pot body, for example. Even if the solidified layer adheres, removing the valve pin from the pot body first and separating the pot body into the body and the lid makes the removal of the residual solidified layer extremely simple. In particular, the heater pot of the present invention exerts a remarkable effect in multicolor production of the same synthetic resin product.

[Brief description of drawings]

FIG. 1 is a sectional view of a fixed mold showing an example of mounting a heater pot according to the present invention.

FIG. 2 is a cross-sectional view showing a structural example of a main part of a heater pot mounting portion.

3A and 3B are a plan view and a sectional view taken along line XY of the lid body of FIGS.

4A and 4B are a cross-sectional view of the body of FIGS. 4A and 4B and a cross-sectional view of an essential part showing an example of attaching a residual solidified layer.

FIG. 5 is a sectional view of a main part of a conventional hot runner type synthetic resin mold.

FIG. 6 is a sectional view of an essential part showing an example of applying a residual solidified layer in a conventional heater pot.

[Explanation of symbols]

1, A heater pot 2, B pot body 3, G body, 3a body body, 3b body flange 4, J resin passage 5, K guideway 6 lid body, 6a disk portion 7 guide portion, 7a guide portion inclination Surface 8, L guide hole 9, V valve pin 12, heater insertion hole, 14, N nozzle, 16 notch, 17
Guide groove 20 Fixed mold, 21 1st plate, 22 2nd plate F collar body, E guide body, H heater, P piston C cavity, R runner, S spool D1 outer diameter of pot body, D2 outside of body collar portion Diameter, d
Body outer diameter T, t Pot body height, m Residual solidified layer θ Inclination angle of guideway

Continuation of front page (58) Fields surveyed (Int.Cl. ⁷ , DB name) B29C 45/00-45/84

Claims (2)

(57) [Claims] 1. A pot body (2) for feeding a molten resin to a cavity (C), which comprises a body (3) having a resin passage (4) in the center and a lid (6) mounted on the body. Then
Heater of hot runner type synthetic resin mold characterized in that the body is provided with a guide path (5) continuous with the resin path, and the lid is provided with a runner (R) and a guide hole (8) continuous with the guide path. pot. 2. A lid (6) constituting the pot body (2)
In the central part of the, the guide part (7) of the valve pin (9) is provided,
A guide groove (1) is formed on the inclined surface (7a) of the body (3) along the guideway (5) of the body, and the guideway communicates with the guideway.
Heater pot of hot runner type synthetic resin mold characterized by having 7) drilled.