JPH03124420A - Cooling method and heat exchange parts for mold - Google Patents

Abstract

PURPOSE:To improve the heat exchanging efficiency by circulating a cooling liquid repeatedly in order toward the shallowest part from the deepest part of a heat exchange part. CONSTITUTION:A cooling liquid is pressure-fed forcibly in the direction of an arrow toward a water stop pillar 28 of a heat exchange parts 23. The cooling liquid is led to one side of a peripheral direction of the first liquid path 29a, after circulation of the same almost a round, the same flows into the second liquid path 29b by passing through the first circulation hole 31 in the vicinity of the water stop pillar 24. The cooling liquid is led in the direction opposite to the first liquid path 29a and passes through the second circulation hole 32 in the vicinity of the water stop pillar 24, in the second liquid path 29b. The cooling liquid passed through the second circulation hole 32 flows into the third liquid path 29c and flows in the direction opposite to the second liquid path 29b. Then the cooling liquid is discharged outside through the third circulation hole 33 formed at a thermal part of the third liquid path 29c. A turbulent flow is generated, by inverting a flowing direction every stage of a liquid path like this and a high heat exchange ratio, which is not obtained with convertional structure, can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to a cooling method and heat exchange parts for a molding die used for injection molding, for example, resin products.

(Prior Art) For example, a mold for injection molding a resin product has a main part configured as shown in FIG. 5, for example.

Molten resin is injected from the sprue 4 formed on the fixed side template 1 into the cavity 3 formed between the fixed side template 1 and the movable side template 2 shown in the figure. The molded product 5 is thereby molded.

Since the shape of such a molded product 5 is not stable immediately after injection, it requires cooling time. Therefore, in order to improve the efficiency of molding work, the cavity 3 of the fixed side template 2 is
A water pipe 6 through which cooling water is circulated is bored in a thick walled portion near the mold, and the cooling water is circulated after the resin is molded to shorten the cooling time of the mold.

Furthermore, on the movable mold plate 2 side, a cooling water circulation circuit as shown in FIGS. 6 and 7 may be provided particularly for the core 7 portion.

The spot type circulation circuit shown in FIG.
A first circulation circuit 8 is bored along the bottom near the bottom of the core 7, and from the middle of the first circulation circuit 8 toward the thick part of the core 7 close to the cavity 3, for example, two
A second book circulation circuit 9.10 is drilled. Partition plates 11.12 whose proximal ends are fixed to the core 7 are inserted into the center of these second circulation circuits 9.10, and the distal ends of these partition plates 11.12 are exposed in an uncoupled state. It communicates with the water circuit on the back side. The cooling water flowing in from one end of the first circulation circuit 8 flows through the partition plates 11, 12 to the vicinity of the cavity 3 of the core 7, as shown by the arrow, and is circulated back. However, in order to obtain a high cooling effect, the second circulation circuit 9
．． It is necessary to provide a plurality of circulation circuits similar to 10, which complicates the structure and tends to increase manufacturing costs.

Next, the spiral type circulation circuit shown in FIG. 7 will be explained.
A cylindrical insertion hole 14 into which the holder is inserted is bored. The heat exchange component 13 has a circular base 1, for example, which engages with the bottom of the core 7 at the base end of the cylindrical main body 15.
Further, a spiral channel wall 17 is formed at a predetermined pitch from the cavity 3 side to the base 16 on the outer periphery of the main body 15.
is provided. The outer peripheral edge of this flow path wall 17 is formed so as to partition it from the inner wall surface of the insertion hole 14. A spiral circulation circuit 18 is formed by this channel wall 17 . A circulation hole 19 bored from the side of the base 1.6 is extended along approximately the center of the main body 15 to near the tip of the heat exchange component and is formed by the flow path wall 17. It is connected to the tip of the circulation circuit 18.

A discharge hole 20 through which cooling water is discharged is provided at the base end of the spiral circulation circuit 18 .

With the heat exchange component 13 formed in this way, the cooling water flowing in from the circulation hole 19 passes through the main body part 15 to the deepest part, flows into the spiral circulation circuit 18 at the deepest part, and then flows into the main body part 15. It flows toward the base end while turning along the outer circumferential side of the tube 15, and is discharged from the discharge hole 20.

By exchanging heat while rotating the core 7 along the portion of the core 7 close to the cavity 3 in this manner, the heat exchange rate can be improved. However, in order to process the spiral channel wall 17 as described above, an NC lathe or NC
It is necessary to use an index table that synchronizes the processing with the milling machine, resulting in high manufacturing costs.

(Problem to be Solved by the Invention) In order to cool the core of a molding die, cooling water circulation such as a spot method or a spiral method has conventionally been used. However, the spot method has the ability to improve cooling efficiency. Moreover, the spiral method requires heat exchange parts, and the processing of these heat exchange parts is extremely difficult and expensive.

The present invention has been made in view of the above-mentioned problems, and an object thereof is to provide a cooling method for a molding die and a heat exchange component that can be manufactured using a general-purpose machine tool and that have high heat exchange efficiency. shall be.

[Structure of the invention] (Means for solving the problem) (1) An insertion part is formed in a molding die, a heat exchange part is inserted into this insertion part, and in the first step, the heat exchange part is axially In a second step, the cooling liquid is caused to flow approximately once in one circumferential direction at the deepest part of the heat exchange component, and in a third step, the coolant is caused to flow along the axial direction of the heat exchange component. In the fourth step, the coolant is made to go around the other direction in the circumferential direction, and in the fifth step, it is returned to the shallow part along the axial direction of the heat exchange component, and the coolant is returned to the shallow part in the deepest part of the heat exchange component. A method for cooling a molding die, in which the cooling liquid is circulated by sequentially repeating the second to fifth steps from the top to the shallowest part.

(2) Form a cylindrical insertion part in the mold body, insert the tubular component body into this insertion part concentrically with a gap in the radial direction, and insert the mold part into the outer periphery of the part body. A plurality of partition walls are provided to form an annular liquid passage by closing the space between the partitions at predetermined intervals in the axial direction. A water stop column is provided which is closed and supplies cooling liquid from the proximal end side of the component body to the deepest part of the liquid path in one direction in the circumferential direction, and the water stop column is provided in each flow direction in the annular liquid path. A heat exchange component in which communication holes are formed in each of the partition wall portions located on the end point side close to the heat exchange parts.

(Function) (1) While the coolant that has been led to the deepest part of the heat exchange part is guided to the shallowest part, a flow is applied to the outer circumference of the heat exchange part, and this flow is reversed every round to cool the part. It generates turbulent flow in the circulation of the liquid and can increase the heat exchange rate compared to normal spiral cooling.

(2) Forming annular partitions at predetermined intervals on the outer periphery of the tubular component body, and installing water stop columns penetrating the partitions can be done using general-purpose machine tools, making them inexpensive. It has a wide range of applications, and can be used for a variety of heat exchanges as a single product, as it can cool molded products that pass inside the tubular component body or molded products located outside.

(Embodiment) A first embodiment of the present invention will be described with reference to FIGS. 1 to 3. The cylindrical one with one end closed shown in the figure is, for example, the core 21 of a molding die, and this core 210
A cylindrical insertion section 2 from the proximal surface to the vicinity of the distal end.
2 is drilled. A heat exchange component 23 is inserted into this insertion portion 22 . This heat exchange component 23 has a tubular component body 24 formed concentrically with a gap between it and the inner wall surface of the insertion portion 22, and a plurality of annular partition walls 25 are integrally formed on the outer periphery of the component body 24. is formed. Note that there are a total of two partition walls 25 in the figure, and the explanation will be made from the deepest part (front end side) to the first partition part 25a1 and the second partition part 25b. These partition walls 25 are connected to the component main body 24.
are formed at predetermined intervals along the axial direction of the annular liquid passage 2, and the outer peripheral edge thereof is in contact with the inner wall surface of the insertion part 22.
9 are formed in a stacked state. In addition, the above-mentioned component body 24
A base 26 is integrally formed at the proximal end portion of. Note that there are a total of three annular liquid paths 29 shown in the figure,
From the deepest part (tip side) first liquid path 29a1 second liquid path 29b
1 will be explained as the third liquid path 29c.

Furthermore, through holes 27 having the same diameter and penetrating in the axial direction of the component body 24 are formed at the same circumferential location in the base 26 and the partition wall 25, respectively.

Water stop columns 28 are inserted into these through holes 27. This water stop column 28 is a circular pipe, the inserted end face is closed, and an inflow hole 3o is bored which communicates with a first liquid path 29a formed from the base end to the deepest part (tip part).

The opening of the inflow hole 30 to the first liquid path 29a opens toward one side of the circumferential direction of the annular first liquid path 29a.

A first flow hole 31 penetrating in the axial direction of the component main body 24 is provided in the first partition portion 25a corresponding to the end point in the flow direction of the first liquid path 29a, which corresponds to the water stop column 28.
is drilled. The cooling liquid that has passed through the first flow hole 31 flows into the second liquid path 29b, and the cooling liquid passes through the first liquid path 29b.
The flow is in the opposite direction to the flow at point a. A second flow hole 32 penetrating in the axial direction of the component body 24 is bored in the second partition wall 25b corresponding to the end point in the flow direction of the first liquid path 29a, which corresponds to the water stop column 28. It is set up.

The cooling liquid that has passed through the second flow hole 32 is transferred to the third liquid path 2.
9c and flows in the opposite direction to the second liquid path 29b. A third flow hole 33 penetrating in the axial direction of the component main body 24 is bored in the base 26 corresponding to the end point in the flow direction of the third liquid path 29c, which is the part immediately before the water stop column 28. has been done. A discharge pipe 34 is connected to the third communication hole 33 from the outer side of the base end of the component body 24 . Note that the water stop column 28 does not completely close the two annular liquid passages, but is inserted with a gap 35 left. Therefore, a small amount of cooling water is
8 through a gap 35.

The heat exchange component 23 formed as described above is inserted into the core 21 and used in a mold 36 configured as shown in FIG. This molding die 36 is the fixed die 3
7 is formed with a sprue 38, and this sprue 38
A cavity 39 is formed in communication with the.

A resin product is molded by injecting the molten resin into the cavity 39, but the molded product does not solidify immediately after injection. When the product shape is in an unstable state, the cooling liquid is forcibly fed to the water stop column 28 of the heat exchange component 23 in the direction of the arrow. The coolant is guided to one side in the circumferential direction of the first liquid path 29a, and after going around the circumference, it passes through the first flow hole 31 near the water stop column 24 and enters the second flow path 29a.
It flows into the liquid path 29b. In this second liquid path 29b, the cooling liquid is guided in the opposite direction to the first liquid path 29a, and the water stop column 24
It passes through the second flow hole 32 in the vicinity of . The coolant that has passed through the second flow hole 32 flows into the third liquid path 29c and flows in the opposite direction to the second liquid path 29b. Then, it is discharged to the outside through the third flow hole 33 formed at the end point of the third liquid path 29c.

In this way, by reversing the direction of the flow at each stage of the liquid path 29, turbulence can be generated and a high heat exchange rate that could not be obtained with the conventional structure can be obtained. Specifically, through experiments, the molding cycle time for deep cylinder molded products was reduced to approximately 3.
We were able to shorten the time by more than 5%. This is equivalent to increasing the production capacity of the molding machine by more than 1.5 times. Further, by increasing the cooling rate, deformation during molding of the product can be reduced, and molding accuracy can be improved.

Furthermore, another usage state of the similar heat exchange component 23 will be described as a second embodiment with reference to FIG. 4.

The molding die 40 shown in the figure is a fixed side die 41,
An insertion portion 43 is bored in a portion corresponding to the sprue 42. A portion S of the sprue 42 communicating with the cavity 44 is formed in the center of the bottom of the insertion portion 43 . Then, the heat exchange component 23 inserted into the insertion portion 43
A through hole 24a whose diameter gradually increases in the injection direction is bored in the center of the tubular component body 24 so as to form a part of the sprue 42.

By configuring in this way, it is also possible to configure the inside of the heat exchange component 23 to be cooled. In other words, when one heat exchange part 23 is used for a small molded product, the first
As shown in the embodiment, it can be used to cool the core 21, and when used in a large molded product, it can be used to cool the sprue 42 as shown in the second embodiment. Since the heat exchange parts 23 can cool a plurality of molds by forming them interchangeably, they are economical and are effective in reducing production costs when responding to low-volume, high-mix production.

Although the heat exchange component 23 used in the above embodiment was used to cool the mold, it is not limited thereto, and can also be used for other heat exchange components. For example, it can be used not only for cooling but also for heating and keeping warm.

[Effects of the Invention] (1) The cooling liquid that has flowed into the deepest part along the axial direction of the heat exchange part is allowed to flow to one side of the outer circumferential direction of the heat exchange part, and the cooling liquid is gradually poured as it moves to the shallower part. By reversing the circumferential flow of the cooling fluid, turbulence can be generated in the cooling fluid during heat exchange.

This makes it possible to obtain a high heat exchange rate that could not be obtained with conventional cooling methods.

(2) Heat exchange parts with an annular partition formed on the outer periphery of the tubular part body can be manufactured using general-purpose machine tools, so they are inexpensive, and water stop columns can be installed to control the flow direction of the liquid path. By drilling the flow holes so as to reverse the flow multiple times, turbulence can be generated and the heat exchange rate can be significantly improved compared to the conventional structure. Furthermore, since both the inside and outside of the heat exchange parts can be cooled, it can be applied to a wide variety of heat exchange parts, and has a wider range of applications than conventional heat exchange parts for molding molds. It is possible to obtain extremely high economic efficiency in the production of various types, and it is effective in reducing product costs.

[Brief explanation of the drawing]

1 to 3 show a first embodiment of the present invention,
Fig. 1 is a perspective view showing a heat exchange part and an insertion hole formed in a molding die, Fig. 2 is a perspective view of the heat exchange part, Fig. 3 is a sectional view showing the configuration of the forming die, and Fig. 4 The figure shows a second embodiment of the present invention, and is a sectional view showing the main parts of a molding die provided with heat exchange parts, and FIGS. 5 to 7 show a conventional example, and FIG. Cross-sectional views 1 and 6 showing the molded product are cross-sectional views showing one example in which a cooling structure is provided for the core, and FIG. 7 is a cross-sectional view showing another example in which a cooling structure is provided for the core. be. 23... Heat exchange part, 24... Part body, 25...
・Partition wall part, 28...Water stop column, 31, 32.33...
Distribution hole, 36...molding mold.

Claims (2)

[Claims] (1) A first step of inserting a cylindrical heat exchange component into the insertion part formed in the molding die and flowing the cooling liquid to the deepest part along the axial direction of the heat exchange component, and the above-mentioned heat exchange A second step in which the cooling liquid is made to go around the entire circumferential direction at the deepest part of the part, a third step in which the cooling liquid is returned to a shallow part along the axial direction of the heat exchange part, and a third step in which the cooling liquid is returned to the shallow part along the axial direction of the heat exchange part; A fourth step of turning the heat exchanger almost once in the other circumferential direction, and a fifth step of returning the heat exchanger to a shallow part along the axial direction of the heat exchanger again, from the deepest part of the heat exchanger part to the shallowest part. A method for cooling a mold by sequentially repeating the second to fifth steps and circulating a cooling liquid. (2) A tubular component body that is inserted concentrically with a gap in the radial direction into an insertion section with a cylindrical wall that is closed at one end, and an axis that is provided on the outer periphery of this component body and that is inserted into the insertion section. A plurality of partition wall portions that are closed at predetermined intervals in the axial direction to form a layered annular liquid path, and a plurality of partition wall portions that penetrate the plurality of partition wall portions in the axial direction and are located approximately at the same location in the circumferential direction of the annular liquid path. and a liquid stop column that supplies medium liquid in one direction from the proximal end side to the deepest annular liquid path through the interior, and a water stop column that is almost closed in the flow direction of the annular liquid path. A heat exchange component characterized in that each partition wall is provided with a communication hole that is formed in the partition wall adjacent to the distal end side of the partition wall and communicates with an adjacent liquid path.