JPH05200786A - Manifold device for hot runner mold - Google Patents

Abstract

PURPOSE:To prevent leakage of resin from the runner lying between a pair of manifold members to the outside of the manifolds in a two-piece type manifold. CONSTITUTION:On the contact surfaces of both manifold members 12, 13, recessed grooves 41, 42 are formed in the form of encircling the whole of a runner 18 from the outside. A core 43 is fitted therein across these recessed grooves 41, 42. A groove-shaped recession 45 is formed on the inside surface of the runner 18 side of the core 43. The resin leaked into the interstice between the contact surfaces of both manifolds 12, 13 from the runner 18 stays in the recession 45. Thus, inner pressure is generated in the recession 45, so that the both end surfaces and outside surface of the core 43 are forced to abut against the corresponding surfaces in the recessed grooves 41, 42. In this manner, an escape of resin to the outside of the manifold 11 can be prevented more positively.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hot runner mold manifold device used for injection molding of thermoplastic resins.

[0002]

2. Description of the Related Art A hot runner mold used for injection molding of a thermoplastic resin always keeps the plastic from the sprue and runner to the vicinity of the gate in a molten state in order to improve the molding efficiency. Further, in the hot runner mold, the runner is formed in the manifold containing the heater. Conventionally, there is a manifold in which a runner is punched in an integral member. By the way, when performing resin change such as color change during molding, it is sufficient to replace the resin in the sprue or the runner, but it may take time due to the retention of the resin in the runner. Therefore, a hot runner mold in which a pair of manifold members are separably joined to form a manifold and a runner is formed between both manifold members has been conventionally used so that the resin accumulated in the runner can be taken out.

Here, an example of a conventional hot runner die of this type will be described with reference to FIG. 5, which schematically shows the construction thereof. In the figure, 1 is a fixed die, 2 is a movable die, and these fixed die 1 and movable die 2 move vertically with respect to each other to open and close, and when a mold is clamped, a plurality of product-shaped cavities 3 are formed. It is formed inside. The fixed mold 1 includes a fixed-side mold plate 4 forming an outer surface of a product, a fixed-side receiving plate 5 attached to a back surface (upper surface in the drawing) of the fixed-side mold plate 4, and an upper surface of the fixed-side receiving plate 5. To the fixed platen of the injection molding machine and a heater (not shown) provided between the fixed side mounting plate 7 and the fixed side receiving plate 5. Manifold with built-in 11
And so on. The manifold 11 is composed of a first manifold member 12 and a second manifold member 13 which are joined together in the vertical direction in the figure. These manifold members 12 and 13 are bolts 14 screwed from the upper side in the figure.
Are fixed to each other and are separable.
Further, the fixed side mounting plate 7 is provided with a nozzle receiving portion 16 to which a nozzle of an injection molding machine is connected. on the other hand,
In the manifold 11, a sprue 17 that communicates with the nozzle receiving portion 16 is formed to vertically penetrate the second manifold member 12, and a runner 18 that branches from the sprue 17 is provided between the manifold members 12 and 13. It is formed on the joint surface (parting line surface). The final branch passage of the runner 18 passes through the first manifold member 12 in the vertical direction and opens at the lower surface thereof. Further, a plurality of bushes 21 are embedded and fixed in the fixed side receiving plate 5 and the fixed side template 4. These bushes 21
The upper surface is in contact with the lower surface of the second manifold member 13, and the inside communicates with the final branch passage of the runner 18, respectively. Each of the bushes 21 has a built-in spear 22, and the inside thereof communicates with a gate 23 formed in the stationary mold plate 4 and opening to the cavity 3. On the other hand, the movable mold 2 is
The movable side template 31 forming the inner surface of the product and the movable side template 31.
Movable side receiving plate 32 attached to the back surface (lower surface in the figure) of 31
And a movable side mounting plate 34 which is mounted on the lower surface of the movable side receiving plate 32 via a spacer block 33 and is mounted on the movable side platen of the injection molding machine. Along with this, between the movable side mounting plate 34 and the movable side receiving plate 32, there is provided a protruding plate 35 which moves up and down relative to the movable side mounting plate 34, and the protruding pin 36 is mounted on the protruding plate 35. Is fixed. These protruding pins 36 are
The movable side receiving plate 32 and the movable side template 31 are slidably pierced so that the front end is located facing the cavity 3. Then, at the time of molding, the molten resin is injected from the nozzle of the injection molding machine with the mold clamped. This resin flows from the sprue 17 through the runner 18 and the spear 22 into the cavity 3 from the gate 23. This cavity 3
After the resin filled therein is solidified, the mold is opened to take out the product which is the solidified resin in the cavity 3. At this time, the ejection pin 36 ejects the product to release it.

In the conventional hot runner mold manifold 11 shown in FIG. 5, both manifold members are used.
The joint surface of 12 and 13 is entirely flat,
Both manifold members 12 and 13 are in contact with each other outside the runner 18.

[0005]

However, in the above-mentioned conventional two-division type manifold 11, both manifold members 12,
Since the joint surface of 13 is entirely flat and both manifold members 12, 13 are in contact with each other outside the runner 18, the resin joins the manifold members 12, 13 from the runner 18. There was a problem that it easily leaked to the outside through the surface.

The present invention is intended to solve such a problem and provides a manifold device of a hot runner mold which can prevent resin from leaking from the runner to the outside through the joint surface of the pair of manifold members. The purpose is to do.

[0007]

SUMMARY OF THE INVENTION The present invention is intended to achieve the above object. According to the invention of claim 1, the first manifold member and the second manifold member are detachably joined. In a hot runner mold manifold device in which a runner is formed between the first manifold member and the second manifold member, the entire runner is outside between the first manifold member and the second manifold member. The resin reservoir space portion is formed by surrounding it.

Further, in the hot-runner mold manifold device of the present invention, the rising portion is provided on one manifold member so as to surround the entire runner from the outside, and the rising portion is fitted to the other manifold member. A concave groove to be fitted is provided, a concave portion is formed on the inner surface of the rising portion on the runner side, and the concave portion forms a resin reservoir space portion.

[0009]

In the hot runner mold manifold device of the present invention, the resin leaks from the runner formed between the first manifold member and the second manifold member between the joint surfaces of both manifold members. Even in this case, the resin is accumulated in the resin reservoir space formed between the manifold members and surrounding the entire runner from the outside, and does not leak to the outside.

Further, in the hot runner mold manifold device of the present invention, the rising portion formed on one manifold member is fitted into the concave groove formed on the other manifold member. When the resin leaks between the joint surfaces of both the manifold members, the resin collects in the resin reservoir space formed by the recess formed on the runner side inner surface of the rising portion and does not leak to the outside of the both manifold members. At the same time, due to the internal pressure generated by the resin flowing into the resin pool space, the end surface and the outer surface of the rising portion are pressed against the corresponding surfaces in the concave groove, whereby the end surface and the outer surface of the rising portion are pressed. The resin is reliably prevented from leaking between the groove and the corresponding surface in the concave groove, and the resin is further surely prevented from leaking to the outside of both manifold members.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described below with reference to FIGS. Since the hot runner mold of this embodiment has substantially the same structure as the conventional mold shown in FIG. 5 described above, the same parts are designated by the same reference numerals and the description thereof will be omitted. However, the different points will be mainly described. In this embodiment, the manifold 11 is composed of a first manifold member 12 and a second manifold member 13 which are also separably joined. And
In the joint surface portion of both the manifold members 12 and 13, the entire runner 18 is surrounded from the outside as shown in FIG.
42 are formed respectively. 1 and 2 of the insert 43 in the groove 41 of the first manifold member 12.
The lower half in the figure is fitted, and the upper half of the nest 43 is a rising portion 44 protruding from the first manifold member 12. The rising portion 44 is fitted in the concave groove 42 of the second manifold member 13. A groove-shaped recess 45 is formed on the inner surface of the rising portion 44 on the runner 18 side.
It is a resin reservoir space 46 between 13 parts. The material of the both manifold members 12 and 13 is, for example, HPM (trade name of Hitachi Metals), and the material of the nest 43 is, for example, brass.

Next, the operation of the above configuration will be described. During molding, when molten resin leaks from the runner 18 formed between the first manifold member 12 and the second manifold member 13 between the joint surfaces of both manifold members 12 and 13, this resin is It flows into and accumulates in the resin reservoir space 46 between the members 12, 13. In this way, the resin is accumulated in the resin reservoir space portion 46, whereby the resin is
It does not leak to the outside of the resin pool space 46. At the same time, the resin flows into the resin reservoir space 46 formed of the recess 45 formed on the inner surface of the insert 43, whereby the recess 45 is formed.
Internal pressure is generated inside, and by this internal pressure, both end surfaces of the insert 43, that is, the upper and lower surfaces shown in FIGS. 1 and 2 and the outer surface on the side opposite to the runner 18 are concave grooves of both manifold members 12, 13.
It is pressed against the corresponding surface in 41, 42. This allows
The resin is reliably prevented from leaking from the resin reservoir space 46 between the both end surfaces and the outer surface of the insert 43 and the corresponding surfaces in the concave grooves 41 and 42, and the resin is further prevented from leaking out of the manifold 11. Certainly prevented.

Next, a second embodiment of the present invention will be described with reference to FIG. In this second embodiment, the entire runner 18 is surrounded from the outside on the joint surface of the first manifold member 12 to the second manifold member 13 by the rising portion.
51 is integrally formed to project, and this rising portion 51 is the second
Groove 52 formed in the corresponding surface of the manifold member 13 of
Is fitted inside. A groove-shaped recess 53 is formed on the inner surface of the rising portion 51 on the runner 18 side, and the recess 53 serves as a resin reservoir space 54. With the configuration of the second embodiment, the same operational effect as that of the first embodiment can be obtained.

The present invention is not limited to the above embodiment, but various modifications can be made. For example,
In the second embodiment, the rising portion 51 is formed in the first manifold member 12 on the fixed side receiving plate 5 side, and the rising portion 51 is formed into the concave groove of the second manifold member 13 on the fixed side mounting plate 7 side.
Although fitted in 52, conversely, a concave groove may be formed in the first manifold member and a rising portion fitted in the concave groove may be formed in the second manifold member.

[0015]

According to the first aspect of the present invention, there is provided a hot runner die manifold device in which a runner is formed between a first manifold member and a second manifold member that are separably joined to each other. Since the resin reservoir space is formed by surrounding the entire runner from the outside between the second manifold member and the second manifold member, even if the resin leaks from the runner to the joint surface of both manifold members, the leaked resin is The resin is prevented from leaking out of both manifold members by accumulating in the resin accumulating space.

Further, according to the invention of claim 2, one of the manifold members is provided with a rising portion, and the other manifold member is provided with a concave groove into which the rising portion is fitted. Form a recess on the inner surface,
Since the resin reservoir space is formed by this recess, the end surface and the outer surface of the rising portion are pressed against the corresponding surfaces in the recessed groove due to the internal pressure generated by the resin flowing into the resin reservoir space. The resin can be more surely prevented from leaking to the outside of both manifold members.

[Brief description of drawings]

FIG. 1 is a sectional view of the entire mold showing a first embodiment of a hot runner mold manifold device of the present invention.

FIG. 2 is a sectional view of the same manifold.

FIG. 3 is a plan view of the same first manifold member.

FIG. 4 is a sectional view of a manifold showing a second embodiment of the present invention.

FIG. 5 is a sectional view of the entire mold showing an example of a conventional hot runner mold manifold device.

[Explanation of symbols]

 12 1st manifold member 13 2nd manifold member 18 Runner 42 Recessed groove 44 Rising portion 45 Recessed portion 46 Recessed space portion 51 Standing portion 52 Recessed groove 53 Recessed portion 54 Resin reservoir space portion

Claims (2)

[Claims] 1. A hot runner mold in which a first manifold member and a second manifold member are separably joined to each other and a runner is formed between the first manifold member and the second manifold member. The manifold device of the hot runner mold, characterized in that the resin runner space is formed between the first manifold member and the second manifold member by surrounding the entire runner from the outside. 2. One of the manifold members is provided with a rising portion projecting from the outside so as to surround the entire runner, and the other manifold member is provided with a concave groove into which the rising portion is fitted. The manifold device for a hot runner mold according to claim 1, wherein a concave portion is formed on the inner side surface, and the resin reservoir space is formed by the concave portion.