JP2004255792A - Manifold apparatus for hot runner type mold - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manifold apparatus for a hot runner type mold in which a material passage (a runner) can be easily cleaned and a mold provided with the runner having a bent part can be easily manufactured. <P>SOLUTION: The manifold apparatus constitutes the material passage to a product cavity in a hot runner type mold. A manifold body with the material passage inside is composed of a pair of manifold members 30 and 40 by separably connecting them. The material passage is formed on a connecting face between the manifold members 30 and 40. The manifold members 30 and 40 are connected with each other by fitting a channel part 33 provided on one part with a tenon part 42 provided on the other part. In addition, The channel part 33 has a sectional shape with a narrower width on an opening side than on the bottom side, and the tenon part 42 has a sectional shape fitted to the sectional shape of the channel part 33. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a hot runner mold manifold device used for injection molding of a thermoplastic resin or the like.
[0002]
[Prior art]
The hot runner type mold improves the molding efficiency and reduces the molding material in the material passage through the molding cycle, such as thermoplastic resin, through the molding cycle so that the molding material in the material passage to the product cavity is not wasted. It is always heated and kept in a molten state.
[0003]
In the hot runner type mold, for example, a runner as a material passage is formed in a manifold in which a heater for heating is incorporated. The runner generally has a bent portion due to branching of a thermoplastic resin into a plurality of product cavities, or incorporation of a valve device for opening and closing a gate from a material passage to the product cavity.
[0004]
In a conventional manifold, a runner is formed by drilling an integral member using a drill or the like. Then, in order to form a bent portion in this runner, holes that intersect with each other are formed by performing perforating processing on members constituting the manifold from two directions, and unnecessary portions of the processed holes as runners are formed. It is closed with a stopper (closing piece) (for example, see Patent Document 1).
[0005]
However, if the bent portion of the runner is formed by drilling, the bent portion of the runner must be sharply bent. If the bent portion of the runner is sharply bent, the resin easily stays in the bent portion, and the staying resin is deteriorated by heating and mixed as foreign matter into the material, which is likely to cause a defect. Moreover, it is difficult to clean the inside of the bent runner formed inside the integral member (manifold).
[0006]
Incorporation of deteriorated materials into products is particularly problematic when molding precision products such as lenses.
Further, by changing only a resin as a molding material to a resin having a different pigment or dye by using the same mold apparatus (so-called color change), products having the same shape and different colors may be formed. When performing color change, before starting molding of the next color product, several injections (shots) from the injection molding machine are performed to discharge the resin of the previous color remaining in the fixed mold runner. However, if the resin stays in the bent portion of the runner as described above, the staying resin is not easily discharged, so a number of shots for color change not for molding the product are required. It has to be performed a number of times, resulting in increased waste of resin and poor productivity. Also, in order to reduce waste of resin, reduce the number of shots for color change, and if the resin of the previous color remains on the runner, this resin will be mixed into the next color product, and the defective molded product Invite.
[0007]
On the other hand, by forming a bent portion of the runner between a plurality of nested members, and connecting these nested members and fitting them into a hole provided in the manifold body, the bent portion of the runner is smoothly curved. A manifold device that suppresses stagnation of a material and facilitates cleaning of a runner has also been proposed (for example, see Patent Document 2).
[0008]
In addition, a manifold device has been proposed in which the entire manifold is divided into two parts and a material passage is formed in a joint surface between members constituting the manifold, so that the inside of the runner can be easily cleaned (for example, Patent Document 1). 3).
[0009]
[Patent Document 1]
JP-A-5-221758 [Patent Document 2]
JP 2002-11756 A [Patent Document 3]
JP-A-5-200787
[Problems to be solved by the invention]
However, in the case of the manifold device in which the bent portion of the runner is formed by the nested member, the bent portion can be easily formed and can be smoothly bent, and the bent portion in the nested member can be easily cleaned. The cleaning of the runner formed on the manifold body is not easy. In addition, in the case of a device in which the entire manifold is divided into two, a smooth bent portion can be easily formed, and the entire runner can be easily cleaned. However, there is a possibility that a problem due to a displacement of two members constituting the manifold may occur. is there.
[0011]
The present invention has been made in view of the above problems, and provides a hot runner-type mold manifold device that can easily clean a material passage (runner) and easily manufacture a mold including a runner having a bent portion. The purpose is to provide.
[0012]
[Means for Solving the Problems]
In order to solve the above-mentioned problem, the invention according to claim 1 is a hot runner type mold, and a manifold device that configures a material passage to a product cavity. It is composed of a pair of manifold members that are separably joined, and a material passage is formed on a joint surface between these manifold members. These manifold members are joined by engagement of a groove provided on one manifold member with a tenon provided on the other manifold member and engaging with the groove. The groove has a cross-sectional shape that is narrower on the opening side than on the bottom side, and the tenon has a cross-sectional shape that matches the cross-sectional shape of the groove.
[0013]
According to the present invention, since the material passage is formed on the joining surface between the manifold members, the bent portion of the material passage is easily formed, and the inside of the material passage is easily cleaned by releasing the joining of the manifold members. can do. Furthermore, since the two manifold members are joined by engaging the groove and the tenon, the two manifold members are less likely to be misaligned. In addition, since the material passage can be formed by forming a groove in the surface of the member instead of drilling with a drill or the like, it is easy to form a bent portion, and it is also easy to apply a mirror finish to the inner surface of the material passage. It is.
Furthermore, since the joining of the two manifold members is realized by a joint structure such as a so-called dovetail joint or a knot joint, the joining structure of the groove portion and the tenon portion prevents the two manifold members from being separated by resin pressure or the like, It is possible to securely join.
[0014]
A hot runner mold manifold device according to a second aspect of the present invention is characterized in that, in the first aspect, the groove portion and the tenon portion are formed in a tapered shape along the longitudinal direction.
[0015]
According to the present invention, a compressive stress is generated between the groove and the tenon due to the tapered shape, and the two manifold members are fixed after being positioned along the longitudinal direction of the groove and the tenon. Can be effectively prevented from being displaced and separated from each other.
[0016]
A hot runner mold manifold device according to a third aspect of the present invention is characterized in that, in the first or second aspect, the material passage is formed on a joint surface between the groove and the tenon.
[0017]
That is, since the material passage is formed in the joining surface, a force is applied to both the manifold members in the separating direction by the pressure of the molding material. On the other hand, according to the present invention, since the material passage is formed on the joint surface between the groove and the tenon, the engaging portion of both manifold members and the material passage are close to each other. Therefore, even if a force in the separating direction is applied by the molding material, the manifold members are not easily opened, so that a gap is hardly generated between the two manifold members, and the molding material is less likely to leak from the material passage.
[0018]
A hot runner mold manifold device according to a fourth aspect of the present invention is characterized in that, in any one of the first to third aspects, a hole is formed in the manifold body and an insert is detachably fitted into the hole. The insert is characterized in that a material passage communicating with the material passage of the manifold member is formed.
[0019]
According to the present invention, the molding material is filled into the product cavity from the material passage of the manifold body through the nested material passage. Then, by removing the insert from the hole of the manifold body after molding, the inner surfaces of the material passage in the manifold body and the material passage in the insert can be easily cleaned.
[0020]
According to a fifth aspect of the present invention, in the hot runner mold manifold device according to the fourth aspect, the nest is formed by detachably connecting a plurality of nest members, and the joining surface between these nest members is made of material. It is characterized in that a passage is formed.
[0021]
According to the present invention, since the material passage of the nest is formed on the joint surface between the nest members, the nest is removed from the manifold body and disassembled into the nest member constituting the nest, thereby easily. The inner surface of the material passage can be cleaned. Further, since the material passage of the nest member can be formed by forming a groove in the surface of the member, it is easy to form a bent portion, and it is also easy to mirror-finish the inner surface of the material passage.
[0022]
According to a sixth aspect of the present invention, there is provided a hot runner mold manifold device according to any one of the first to fifth aspects, further comprising a screw member for connecting the manifold members.
[0023]
According to the present invention, since the manifold members can be fixed to each other by the screw members, the separation between the two manifold members can be more reliably prevented.
[0024]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 shows a hot runner type mold. In this figure, 10 is a fixed mold and 20 is a movable mold. The fixed mold 10 and the movable mold 20 move up and down in the figure to open and close. A plurality of product cavities C are formed inside at the time of mold clamping.
[0025]
The fixed mold 10 includes a fixed mold plate 11 that forms the outer surface of the product, a fixed receiving plate 12 attached to the back (upper surface in the drawing) of the fixed mold plate 11, and an upper surface of the fixed receiving plate 12. A fixed-side mounting plate 14 mounted via a spacer block 13 and mounted on a fixed-side platen of an injection molding machine, and a heater (not shown) provided between the fixed-side mounting plate 14 and the fixed-side receiving plate 12. And a built-in manifold device.
[0026]
This manifold device has a manifold body 15 including a first manifold member 30 and a second manifold member 40 joined in the vertical direction in the figure. These manifold members 30, 40 are fixed to each other by bolts S screwed from the upper side in the figure, and are separable.
[0027]
Further, the fixed side mounting plate 14 is provided with a nozzle receiving portion 16 to which a nozzle of the injection molding machine is connected. On the other hand, a sprue 31 penetrating the first manifold member 30 in the up-down direction and communicating with the nozzle receiving portion 16 is formed in the manifold main body 15, and a runner (material passage) 32 branched from the sprue 31 has both ends. It is formed on the joint surface between the manifold members 30 and 40.
[0028]
From both ends of the runner 32, runners (material passages) 41 which penetrate the second manifold member 40 in the up-down direction and open on the lower surface thereof are formed. A plurality of bushes 17 are embedded and fixed in the fixed-side receiving plate 12 and the fixed-side mold plate 11. The upper surfaces of these bushes 17 are in contact with the lower surface of the second manifold member 40, and the insides are in communication with the runners 41, respectively. Each bush 17 has a built-in spear 18 and communicates internally with a gate 19 formed on the fixed mold plate 11 and opening to the product cavity C.
[0029]
On the other hand, the movable mold 20 includes a movable mold plate 21 that forms the inner surface of the product, a movable receiving plate 22 attached to the back surface (the lower surface in the drawing) of the movable mold plate 21, And a movable-side mounting plate 24 mounted on a movable-side platen of the injection molding machine mounted on a back surface via a spacer block 23. At the same time, a protruding plate 25 is provided between the movable-side mounting plate 24 and the movable-side receiving plate 22 and moves up and down relative to the drawing, and a protruding pin 26 is fixed to the protruding plate 25. Have been. These protruding pins 26 are slidably penetrated through the movable-side receiving plate 22 and the movable-side mold plate 21, and have their front ends facing the product cavity C.
[0030]
Here, the manifold body 15 constituting the manifold device will be described with reference to FIGS.
The manifold body 15 having the runners 32 and 41 therein has a configuration including a pair of manifold members 30 and 40 that are separably joined. The two manifold members 30 and 40 are joined by engagement of a groove 33 provided on the first manifold member 30 and a tenon 42 provided on the second manifold member 40 and engaging with the groove 33.
[0031]
The groove portion 33 has a cross-sectional shape having a narrow portion 33a that is narrower on the opening side than on the bottom side. The tenon 42 engaging with the groove 33 has a sectional shape having a constricted portion 42 a that matches the sectional shape of the groove 33. That is, the inner surface of the groove 33 and the outer surface of the tenon 42 have the same shape, and the groove 33 and the tenon 42 are fitted to each other, as shown in FIG. It is fitted without.
[0032]
Further, the groove 33 and the tenon 42 are tapered along the longitudinal direction. That is, the dimensions a1 and a2 shown in FIG. 2 are the width dimensions on the one end faces 30a and 40a side of the groove 33 and the tenon part 42, and the dimensions b1 and b2 are the width dimensions on the other end faces 30b and 40b. a1> b1, a2> b2 are satisfied.
Then, the groove 33 on the one end surface 30a side of the first manifold member 30 and the tenon portion 42 on the other end surface 40b side of the second manifold member 40 are aligned with each other, so that the two manifold members in the direction of the arrow shown in FIG. The manifold body 15, which is formed by joining the pair of manifold members 30, 40, is formed by sliding the end plates 30, 40 until the end surfaces 30a and 40a and the other end surface 30b and the other end surface 40b are fitted to each other. Is done.
[0033]
The runner 32 is formed by a runner forming groove 32 a formed on the surface 33 b of the groove 33 and a runner forming groove 32 b formed on the runner forming groove 32 b formed on the surface 42 b of the tenon 42. That is, when the two manifold members 30 and 40 are joined without a gap, the runner forming groove 32a and the runner forming groove 32b formed in the two members 30 and 40 are integrally connected, and the gap between the two manifold members 30 and 40 is formed. The runner 32 is formed on the joint surface p. The runner 32 is desirably formed on the joint surface p because the joint surface p between the groove 33 and the tenon portion 42 is more strongly joined than the joint surface q when the two manifold members 30 and 40 are joined.
[0034]
The manifold body 15 can be manufactured, for example, as follows. First, a groove 33 is formed in a plate-like member that becomes the first manifold member 30, and a tenon portion 42 that fits into the groove 33 is formed in a plate-like member that becomes the second manifold member 40. The groove 33 and the tenon 42 are tapered in the longitudinal direction. Then, these plate-like members are joined by fitting the groove 33 and the tenon 42 to determine the mutual position of both members.
[0035]
The two plate-shaped members whose mutual positions were determined were once disassembled, and a through hole serving as a sprue 31 was formed in a member serving as the first manifold member 30 by a boring process using a drill or the like, and a milling machine or the like was used. The runner forming groove 32a is formed by groove processing. Similarly, in the member to be the second manifold member 40, a through hole to be the runner 41 is formed by drilling, and the runner forming groove 32b is formed by groove processing. Further, the inner surfaces of the through holes and the grooves are mirror-finished so that the molding material flows smoothly.
[0036]
Then, the two plate-shaped members having the through holes and the groove formed therein are joined by fitting the groove 33 and the tenon 42 to each other, and a female screw hole (not shown) is formed in the second manifold member 40 by the first manifold. If a bolt through-hole (not shown) having a counterbore portion is formed in the member 30 and screwed with a bolt S, the manifold body 15 having the runners 32 and 41 therein can be easily manufactured.
[0037]
In the hot runner type mold configured as described above, at the time of molding, the molten resin is injected from the nozzle of the injection molding machine while the mold is clamped. The molten resin flows from the sprue 31 through the runners 32, 41 and around the spear 18 in each bush 17, and flows into the product cavity C from the gate 19. After the resin filled in the product cavity C is solidified, the mold is opened, and when the product, which is the resin solidified in the product cavity C, is taken out, the ejection pin 26 projects the product and releases the product.
[0038]
At the time of color change, if the manifold body 15 is detached from the apparatus and disassembled into the first manifold member 30 and the second manifold member 40, the inside of the material passage (the sprue 31, the runner 32 and the runner 41) can be easily cleaned. can do.
[0039]
As described above, in the manifold body 15 of this manifold device, the sprue 31 and the runner 41 are provided as short through holes, and the long runner 32 is provided separately along the longitudinal direction. And the work of cleaning the inside of the material passage at the time of molding is facilitated.
[0040]
FIGS. 4A and 4B show a second embodiment of the hot runner type manifold device. This manifold device includes a manifold body 50 having a material passage, a heater for heating a molding material in the material passage, and the like. Here, the configuration of the manifold body 50 will be described, and description of other parts will be omitted. .
[0041]
As shown in FIG. 4 (a), the two manifold members 51 and 52 of the manifold body 50 are joined in the vertical direction in the figure by the engagement of the tapered groove and tenon as shown in FIG. ing. A sprue 50b to which a nozzle of an injection molding machine is connected is connected to a runner (material passage) 50a provided across the joining surface r of the two manifold members 51 and 52, and runners 50c and 50d extending toward each cavity. Is provided.
[0042]
In the manifold body 50, holes 52a, 52b penetrating the manifold member 52 are formed, and inserts 53, 54 having runners 50c, 50d are detachably fitted in the holes 52a, 52b, respectively. ing. The holes 52a and 52b and the inserts 53 and 54 are formed in a tapered shape in which the joint surface r side is wide, and the inserts 53 and 54 are inserted into the hole portions 52a and 52b from the joint surface r side. The taper fit allows positioning in the vertical direction in the figure. FIG. 4B is an arrow view along the line IV-IV in FIG. 4A, and shows a state in which the bonding surface r is viewed from above in FIG. 4A.
[0043]
The manifold body 50 can be manufactured, for example, as follows. First, a groove is formed in a plate-shaped member serving as the manifold member 51, a tenon portion fitted in the groove is formed in the plate-shaped member serving as the manifold member 52, and holes 52a and 52b for fitting the inserts 53 and 54 are formed. . The groove and the tenon are tapered in the longitudinal direction as shown in FIG. Then, the inserts 53 and 54 are fitted into the holes 52a and 52b, and the groove and the tenon are fitted together, so that these plate-like members and the inserts 53 and 54 are joined, and the mutual positions of the members are determined. To determine.
[0044]
The members whose mutual positions have been determined are temporarily disassembled, and a through hole serving as a sprue 50b is formed in the member serving as the manifold member 51 by drilling using a drill or the like, and the runner 50a is formed by groove processing using a milling machine or the like. Form the upper half. Similarly, the lower half of the runner 50a is formed in the member to be the manifold member 52 by groove processing. Further, in each of the inserts 53 and 54, the lower half of the end of the runner 50a is formed on the upper end surface by groove processing, and the runners 50c and 50d connected thereto are formed by drilling.
The inner surface of each runner is mirror-finished so that the molding material flows smoothly.
[0045]
Then, the runner and the member formed with the sprue are combined, the groove and the tenon are fitted and joined together, and a female screw hole (not shown) in the manifold member 52 and a bolt through hole having a spot facing portion in the manifold member 51 are provided. By forming (not shown) and fixing with screws or the like, the manifold main body 50 having the sprue 50b and the runners 50a, 50c, 50d therein can be manufactured.
[0046]
In the manifold body 50 of this manifold device, the sprue 50b and the runners 50c and 50d are provided as short through holes, and the long runner 50a is divided and provided along the longitudinal direction. The work of cleaning the inside of the material passage during molding is facilitated.
[0047]
The components, their shapes, combinations, and the like shown in the above embodiments are merely examples, and can be variously changed based on design requirements without departing from the spirit of the present invention.
For example, if the nest is configured such that a plurality of nest members are detachably connected to each other and a material passage is provided on a joint surface thereof, a bent portion of the runner can be easily formed inside the nest, and a complicated structure can be obtained. Production and cleaning can be easily performed even with a runner having a simple shape.
[0048]
【The invention's effect】
As described above, according to the manifold device of the hot runner type mold according to claim 1 of the present invention, since the material passage is formed on the joint surface between the manifold members constituting the manifold body, the material passage is formed. The formation of the bent portion is easy, and the inside of the material passage can be easily cleaned by releasing the joining of the manifold member, so that the waste of material at the time of color change can be reduced.
Furthermore, since the two manifold members are joined by engaging the groove and the tenon, the two manifold members are less likely to be displaced from each other, and it is possible to prevent inconvenience caused by leakage of the molding material from the gap.
In particular, since the joining of the two manifold members is realized by a joint structure such as a so-called dovetail joint or a seam joint, the joining structure of the groove and the tenon portion prevents the two manifold members from being separated by resin pressure or the like, It is possible to securely join.
In addition, since the material passage can be formed by forming a groove in the surface of the member instead of drilling with a drill or the like, it is easy to form a bent portion, and it is also easy to apply a mirror finish to the inner surface of the material passage. Therefore, the molding material flows smoothly in the material passage and is less likely to stay, so that it is possible to suppress the occurrence of problems such as mixing of the deteriorated material into the product.
[0049]
According to the manifold device of the hot runner type mold according to the second aspect of the present invention, a compressive stress is generated between the groove and the tenon due to the tapered shape, and both the manifold members are positioned along the longitudinal direction of the groove and the tenon. Since it is fixed after being removed, it is possible to effectively prevent displacement and separation between the two manifold members. Therefore, steps and gaps in the material passage due to misalignment between the manifold members are less likely to occur, and a smooth material passage is formed, so that the molding material can flow smoothly.
[0050]
According to the manifold device of the hot runner type mold according to the third aspect of the present invention, since the material passage is formed along the groove and the tenon, the manifold members are less likely to open even when pressure due to the molding material is applied. In addition, the molding material is less likely to leak from the gap between the two manifold members, and problems due to the stagnation of the deteriorated material can be prevented.
[0051]
According to the manifold device of the hot runner type mold according to the invention of claim 4, the molding material is filled into the product cavity from the material passage of the manifold body through the material passage of the nest, and after molding, the nest is filled with the manifold body. By removing from the holes, the inner surfaces of the material passage in the manifold body and the material passage in the nest can be easily cleaned. Therefore, a complicatedly bent material passage can be easily formed and the inside thereof can be easily cleaned, so that even in a mold having a large number of cavities, the color can be easily changed without wasting a large amount of material. It is possible to do.
[0052]
According to the manifold device of the hot runner type mold according to the invention of claim 5, since the material passage of the nest is formed on the joint surface between the nest members, the nest is removed by removing the nest from the manifold body. The inner surface of the material passage can be easily cleaned by being disassembled into the nested members. Further, since the material passage of the nest member can be formed by forming a groove in the surface of the member, it is easy to form a bent portion, and it is also easy to mirror-finish the inner surface of the material passage. Therefore, even a material passage that is bent in a complicated manner can be formed more easily, and the inside thereof can be easily cleaned.
[0053]
According to the manifold device of the hot runner type mold according to the invention of claim 6, since the manifold members can be fixed to each other by the screw member, no gap is generated between the two manifold members, and the manifold members are formed by the pressure of the molding material. Can be more reliably prevented, and leakage of the molding material and damage to the manifold member can be effectively prevented.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view illustrating a manifold device of a hot runner type mold according to an embodiment of the present invention.
FIG. 2 is a perspective view showing a configuration of a manifold body of the manifold device shown in FIG.
FIG. 3 is a perspective view showing a state in which two manifold members constituting the manifold body are fixed by engagement of a groove and a tenon;
FIG. 4 is a sectional view (a) showing a configuration of a manifold body in a manifold apparatus of a hot runner type mold according to another embodiment of the present invention, and a view taken along an arrow IV-IV in FIG. 4 (a) ( b).
[Explanation of symbols]
15 Manifold body 30 First manifold member 32 Runner (material passage)
33 groove portion 40 second manifold member 41 runner (material passage)
42 Mortice 50 Manifold body 50a Runner (material passage)
50c, 50d Runner (material passage)
51, 52 Manifold members 52a, 52b Holes 53, 54 Inserts p, q, r Joining surface S Bolt (screw member)
C Product cavity

Claims (6)

A manifold device for forming a material passage to a product cavity in a hot runner type mold,
A manifold body that forms the material passage therein includes a pair of manifold members that are separably joined, and the material passage is formed on a joint surface between these manifold members.
Both manifold members are joined by a groove provided on one of the manifold members and a tenon engaged with the groove provided on the other manifold member,
The hot runner, wherein the groove has a cross-sectional shape that is narrower on the opening side than on the bottom side, and the tenon has a cross-sectional shape that matches the cross-sectional shape of the groove. Type mold manifold device. The hot runner mold manifold device according to claim 1, wherein the groove and tenon are tapered along the longitudinal direction. The hot runner type manifold apparatus according to claim 1, wherein the material passage is formed on a joint surface between the groove and the tenon. A hole is formed in the manifold main body, and an insert is detachably fitted in the hole, and a material passage communicating with the material passage is formed in the insert. The hot runner type manifold apparatus according to any one of claims 1 to 3. The hot runner type according to claim 4, wherein the nest comprises a plurality of nesting members detachably connected to each other, and the material passage is formed at a joint surface between the nesting members. Mold manifold device. The hot runner type manifold apparatus according to any one of claims 1 to 5, further comprising a screw member that couples the manifold members.

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