JPH1147902A - Local cooling structure of mold - Google Patents

Abstract

PROBLEM TO BE SOLVED: To effectively execute the local cooling in a metallic mold providing complicated cavity by communicating a cooling water supplying source to one end side of a local cooling passage having a return-back part in the inner part of a columnar part constituting the cavity surface in the metallic mold. SOLUTION: The cooling water from the cooling water supplying source 5 is spouted from the opening hole of a cooling water supplying pipe 4 and then, the cooling water supplying pipe 4 is eccentrically arranged, and since this opening hole faces the one end part 7a of the local cooling passage 7 and is approached to it, the large part of the cooling water flows into the local cooling passage 7 through the one end part 7a. The cooling water which flows into the local cooling passage 7 through the one end part 7a flows from a going way part 7c to a return-back part 7d and further, flows from the return- back part 7d to a coming-back way part 7e to cool the columnar part 7 in this process. The cooling water flows into a first cooling passage 3 from the coming-back way part 7e through the other end part 7b and flows as the confluence with the cooling water which does not flow into the local cooling passage 7 and thereat, the inner part of the metallic mold 1 is cooled.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cooling structure formed inside a mold, and more particularly to a local cooling structure for a mold having a complicated cavity surface.

[0002]

2. Description of the Related Art Materials such as aluminum and resin injected into a mold cavity are extremely hot, and the mold takes away the heat of these materials, cools and solidifies the material, and increases the temperature of the mold itself. In order to prevent this, a cooling function is required.
For this reason, a cooling structure is usually provided inside the mold.

A conventional mold cooling structure will be described with reference to FIGS. FIG. 14, FIG.
FIG. 5 is a diagram showing the most commonly used mold cooling structure. In FIG. 14, a column 1 is formed on a cavity surface B of a mold 1 in order to form a shape indicated by reference numeral A in the figure. To cool the vicinity of the columnar portion 2, a first cooling passage 3 is formed in the mold 1.
A cooling water supply pipe 4 is inserted into the cooling passage 3 so that the cooling water reaches the tip of the cooling passage 3. And
The cooling water is blown out from the tip of the cooling water supply pipe 4 into the cooling passage by water pressure from a cooling water supply source connected to an end (not shown) of the cooling water supply pipe 4 to cool the vicinity of the columnar portion 2. is there.

In the cooling structure of FIG. 14 described above, if the diameter of the columnar portion 2 is small, the cooling passage 5 cannot be formed inside the columnar portion 2. Therefore, there is a problem that the temperature of the columnar portion 2 becomes higher than that of other cavity surfaces, and galling occurs due to image sticking in this portion. As shown in FIG. 15, there is also a method of directly injecting cooling water to the columnar portion 2 with the injector 14 in a state where the mold 1 is opened, but it is necessary to newly provide such a cooling water injection step. At the same time, the injected cooling water remains as impurities 13 on the cavity surface, which causes a problem in that the appearance is poor, or a gas is generated during casting or the like, resulting in a defect in a cavity.

FIG. 16 shows a conventional example in which the columnar portion 2 is effectively cooled. This is because a local cooling passage 7 having a small diameter extends from the end of the first cooling passage 3 having a large diameter into the columnar portion 2, and a very thin cooling water supply is provided from the first cooling passage 3 to the local cooling passage 7. In this configuration, a pipe 4 is inserted. Cooling water is supplied from a cooling water supply source connected to an end of the cooling water supply pipe 4 (not shown).
Cooling water is spouted from the tip of. The cooling water passes through the narrow gap between the local cooling passage 7 and the cooling water supply pipe 4 and the columnar portion 2
Is cooled and communicated with the first cooling passage 3.

[0006]

With the cooling structure shown in FIG. 16, since the cooling water reaches the inside of the columnar portion 2, a mold having a complicated cavity surface can be effectively formed. The cooling water can be cooled. However, since the cooling water supply pipe 4 is inserted into the small-diameter local cooling passage 7, the cooling water ejected from the tip of the cooling water supply pipe 4 is cooled by the local cooling passage 7. After returning to the first cooling passage 3 through a very narrow gap with the water supply pipe 4. For this reason, there is a problem that even if a small amount of solid matter is mixed in the cooling water, the cooling passage is closed, and the cooling function cannot be performed.

SUMMARY OF THE INVENTION Accordingly, the present invention has been made in view of the above circumstances, and effectively cools a mold having a complicated cavity shape such as a columnar portion and prevents a cooling passage from being blocked. It is a technical task to improve the reliability as a cooling function.

[0008]

Means for Solving the Problems According to the first aspect of the present invention, which has been made to solve the above-mentioned technical problem, a folded portion is formed in a convex portion forming a cavity surface of a mold. The mold has a local cooling structure including a local cooling passage having the cooling water supply source for supplying cooling water to the local cooling passage.

According to the above-mentioned invention, the local cooling passage enters into the convex portion forming the cavity surface of the mold, and has a folded portion in the convex portion. The cooling water supplied from the cooling water supply source enters the local cooling passage formed in the convex portion, turns the inside of the convex portion at the turning portion, and returns from the local cooling passage after turning. As described above, since the cooling water flows through the local cooling passage via the turn-back portion, it is possible to supply sufficient cooling water to the local cooling passage without providing a cooling water supply pipe in the local cooling passage, which is complicated. It is possible to effectively perform local cooling of a mold having a special cavity shape, and to have a sufficiently large cross-sectional area of the cooling water passage in the local cooling passage, so that the cooling water passage is not blocked. is there.

Further, in solving the above technical problem, as in the invention of claim 2, the local cooling passage is formed in a substantially V-shaped vertical cross section formed in a convex portion forming a cavity surface of the mold. Preferably it is a hole. According to this, since the local cooling passage is formed by a hole having a substantially V-shaped cross section, holes can be formed in the mold in two directions by electric discharge machining, a drill or the like, and the leading ends of the holes can be easily communicated. A local cooling passage can be formed at the bottom. Therefore, the processing of the local cooling passage can be easily performed.

In this case, the two ends of the local cooling passage communicate with a first cooling passage in which a cooling water supply pipe communicating with the cooling water supply source is disposed, and the cooling device has a cooling water supply source. It is preferable that the water supply pipe is provided in the first cooling passage so that an opening thereof faces and is close to one end of the local cooling passage. According to this, since the cooling water supply pipe arranged in the first cooling passage is arranged so that its opening faces and is close to one end of the local cooling passage, it is ejected from the cooling water supply pipe. Cooling water enters at one end of the local cooling passage and is discharged at the other end. Therefore, there is an effect that a large amount of stable water is supplied into the local cooling passage and the cooling capacity is improved.

According to a fourth aspect of the present invention, both ends of the local cooling passage communicate with a first cooling passage in which a cooling water supply pipe communicating with the cooling water supply source is disposed. The supply pipe may be bent so that its opening faces and is close to one end of the local cooling passage. According to this, the tip of the cooling water supply pipe is bent, and its opening faces and is close to one end of the local cooling passage, so that the mounting position of the cooling water supply pipe is at the center of the first cooling passage. In addition, the cooling water supply pipe can be easily manufactured and attached, and the cooling capacity can be improved by supplying a large amount of stable water into the local cooling passage.

[0013] The invention of claim 5 is the invention according to claim 1 or 2.
, One end of the local cooling passage communicates with a second cooling passage communicating with the cooling water supply source, and the other end of the local cooling passage communicates with a third cooling passage communicating with the cooling water discharge source. . According to this, since the entrance (the one end and the other end) of the local cooling passage is separated, there is no need to attach a cooling water supply pipe, and all the supplied cooling water flows into the local cooling passage. be able to. Further, with such a configuration, the distance (pitch) between one end and the other end of the local cooling passage can be freely set to be equal to or more than the workable distance of the local cooling passage. If a local cooling passage extending in the longitudinal direction is formed, such an elongated rib can be entirely cooled over a wide range. In such a configuration,
By forming the openings constituting one end and the other end of the local cooling passage obliquely coaxially with the local cooling passage, the processing of the local cooling passage is further simplified, and the cooling range thereof can be expanded.

According to a sixth aspect of the present invention, the local cooling passage has a bottomed hole formed in the projection and the bottomed hole in the inserted portion which is inserted halfway through the bottomed hole. And a partition wall that divides the cross section into two.
According to this, since the local cooling passage is constituted by the bottomed hole and the partition wall separating the bottomed hole, when machining the local cooling passage, only one bottomed hole having an arbitrary shape is machined in the mold. In this case, by forming the bottomed hole so that the thickness of the mold becomes constant, the temperature distribution of the mold can be made uniform and the thermal stress can be reduced. Can be reduced.

[0015] More preferably, the cooling water supply pipe is fixedly supported in the first cooling passage. By fixedly supporting the cooling water supply pipe, the positional accuracy of the cooling water supply pipe is improved, and variations in cooling capacity can be reduced.

[0016]

Embodiments of the present invention will be described below with reference to the drawings. The same parts as those of the prior art are denoted by the same reference numerals, and the detailed description thereof will be omitted.

(First Embodiment) FIG. 1 shows a first embodiment of the present invention.
It is a figure showing a local cooling structure of a metallic mold which is an example of an embodiment.
In the figure, a mold 1 includes a columnar portion 2 on a cavity surface B. The first cooling passage 3 is formed in the mold 1 by drilling or the like. A cooling water supply pipe 4 is arranged in the first cooling passage 3. The cooling water supply pipe 4 communicates with a cooling water supply source 5. As the cooling water supply source 5, for example, a discharge port of a utility pipe using industrial water piped to a factory or the like is used. On the other hand, the first cooling passage 3 communicates with a cooling water discharge source 6. Cooling water discharge source 6
For example, an outlet of a utility pipe using industrial water piped to a factory or the like is used. Generally, the cooling water discharged from the outlet of the utility pipe is cooled and purified by a cooling tower or the like, and forms a circulation system returning to the outlet of the utility pipe.

A local cooling passage 7 communicates with the tip of the first cooling passage 3. The local cooling passage 7 has one end 7
a and the other end 7b are opened at different positions at the tip of the first cooling passage 3, and the passage formed between both ends is formed by penetrating into the columnar portion 2 constituting the cavity surface of the mold 1. Have been. Then, it enters the columnar portion 2 from the one end portion 7a through the outward path portion 7c, is once folded at the folded portion 7d in the columnar portion 2, and travels from the folded portion 7d to the other end portion 7b via the return path portion 7e. As is clear, the vertical section is a substantially V-shaped hole. The local cooling passage 7 having such a shape is formed by forming two holes in the columnar portion 2 by electric discharge machining or the like and connecting the ends of both holes in the columnar portion 2.

The cooling water supply pipe 4 is arranged eccentrically in the first cooling passage 3, and has an opening facing one end 7 a of the local cooling passage 7.

In the above configuration, the cooling water from the cooling water supply source 5 is spouted from the opening of the cooling water supply pipe 4. At this time, the cooling water supply pipe 4 is arranged eccentrically and the opening is locally cooled. Most of the cooling water enters the local cooling passage 7 from the one end 7a because it faces and is close to the one end 7a of the passage 7. The cooling water that has entered the local cooling passage 7 from the one end 7a flows from the forward path 7c to the turn-back part 7d, further from the turn-back part 7d to the return path 7e, and cools the columnar part 2 during this process.

The cooling water flows into the first cooling passage 3 from the return path 7e via the other end 7b. At this time, since the other end 7b does not face the cooling water supply pipe 4, the cooling water flows through the first cooling passage 3 without obstructing the jetting, and the local cooling passage 7
The cooling water that has not flowed into the mold 1 joins the cooling water, cools the inside of the mold 1, further reaches the cooling water discharge source 6, and is discharged.

As described above, in the present embodiment, the local cooling passage 7 is formed by entering the columnar portion 2 constituting the cavity surface B of the mold 1, and the local cooling passage 7 is connected to one end 7a and the outward passage 7c. , The return path 7d, the return path 7e, and the other end 7b, the cooling water flow path is the forward path 7c, the return section 7d,
It is not necessary to provide the cooling water supply pipe during the return path 7e. Therefore, the columnar portion 2 can be effectively cooled, and the blockage of the cooling water flow path can be prevented.

Further, since the local cooling passage 7 is a hole having a substantially V-shaped vertical section, holes are formed in the mold by electric discharge machining, a drill or the like in two directions when machining the hole. The local cooling passage can be easily formed by connecting the leading ends.

The cooling water supply pipe 4 is arranged eccentrically in the first cooling passage 3, and its opening faces the one end 7 a of the local cooling passage 7 so as to be close to the local cooling passage 7. A large amount of cooling water can be supplied into the cooling passage, and there is an effect that a stable and high cooling capacity is exhibited.

(Second Embodiment) Next, a second embodiment of the present invention will be described with reference to FIG. 2. This embodiment is different from the first embodiment in the arrangement of cooling water supply pipes. And only the shape is different.
Since this embodiment is the same as the embodiment, the differences will be mainly described below.

In FIG. 2, the cooling water supply pipe 4 is disposed in the center of the first cooling water passage 3 at the center thereof, the tip 4a is bent, and its opening faces one end 7a of the local cooling passage 7. And are in close proximity. The other configuration is the same as that of the first embodiment, and a detailed description thereof will be omitted.

In the above configuration, the cooling water from the cooling water supply source 5 is jetted from the opening of the cooling water supply pipe 4, and at this time, the cooling water supply pipe 4 is bent.
This allows the opening to face the one end 7a of the local cooling passage 7, so that the cooling water enters the local cooling passage 7 from the one end 7a. The cooling water flows from the forward path portion 7c to the return portion 7d, and further from the return portion 7d to the return portion 7e, and cools the columnar portion 2 during this process.

In this embodiment, the distal end portion 4a of the cooling water supply pipe 4 is bent, and its opening faces the one end portion 7a of the local cooling passage 7 so as to be close to the first embodiment. A similar effect can be obtained, and a cooling water supply pipe component can be easily manufactured.

(Third Embodiment) Next, a third embodiment of the present invention will be described with reference to FIGS. 3 to 7. The same parts as those in the first embodiment are denoted by the same reference numerals. A detailed description thereof will be omitted.

In FIG. 3, a second cooling passage 8 and a third cooling passage 9 are formed in the mold 1 by drilling or the like. The second cooling passage 8 communicates with the cooling water supply source 5. On the other hand, the third cooling passage 9 communicates with the cooling water discharge source 6. The local cooling passage 7 communicates with the distal ends of the second cooling passage 8 and the third cooling passage 9. Local cooling passage 7
The one end 7a opens at the tip of the second cooling passage and the other end 7b opens at the tip of the third cooling passage, and the passage formed between both ends constitutes the cavity surface of the mold 1. It is formed so as to penetrate into the columnar portion 2. Other configurations are the same as those of the first embodiment, and a detailed description thereof will be omitted.

In the above configuration, the cooling water from the cooling water supply source 5 first enters the second cooling passage 8 and the second cooling passage 8
Enters the local cooling passage 7 from one end 7a which is opened at the tip end. The cooling water that has entered the local cooling passage 7 from one end 7a is
From the outward path portion 7c to the return portion 7d, and further to the return portion 7d
The flow from d to the return path 7e cools the columnar section 2 during this process. The cooling water flows from the return path 7e to the third end via the other end 7b.
The water flows into the cooling passage 9, reaches the cooling water discharge source 6, and is discharged.

In this embodiment, one end 7a of the local cooling passage 7 communicates with a second cooling passage communicating with the cooling water supply source 5, and the other end of the local cooling passage 7 communicates with a third cooling water discharge source. Since it is configured to communicate with the cooling passage, there is no need to attach a cooling water supply pipe, and all the cooling water can flow into the local cooling passage. As shown in the application examples of FIGS. 4 and 5, the second cooling passage 8 and the third cooling passage 8 are connected to each other.
The pitch between the cooling passage 9 and the local cooling passage 7 can be freely set to be equal to or greater than the workable distance of the local cooling passage 7. For example, if a local cooling passage extending in the longitudinal direction is formed in a local portion such as an elongated rib, the number is relatively small. Such an elongated rib can be cooled over a wide area by the number of cooling. As shown in the application example of FIGS. 6 and 7, if the second cooling passage 8 and the third cooling passage 9 themselves are formed coaxially and obliquely with the local cooling passage 7, the processing of the local cooling passage 7 is further improved. It ’s easy,
The cooling range is also expanded.

(Fourth Embodiment) Next, a fourth embodiment of the present invention will be described with reference to FIGS.
This embodiment differs from the first embodiment in the configuration of the local cooling passage, and the following description will focus on the differences.

In FIG. 8, a first cooling passage 3 is formed in a mold 1 by electric discharge machining or the like. A cooling water supply pipe 4 is arranged in the first cooling passage 3. A local cooling passage 7 extending inside the columnar portion 2 constituting the cavity of the mold 1 communicates with the tip of the first cooling passage 3. The local cooling passage 7 has one bottomed hole 10 and one bottomed hole 1.
It consists of a partition wall 11 inserted halfway through zero. The partition wall 11 is arranged so as to divide the cross section of the bottomed hole 10 in a portion where the partition wall 11 is inserted into two. The unit 7e. And the partition wall 11 of the bottomed hole 10
The folded portion 7c is constituted by the portion where no is inserted.
In the portion of the bottomed hole 10 that opens to the first cooling passage 3, the left opening in the figure partitioned by the partition wall 11 is one end 7a of the local cooling passage, and the right opening in the drawing is the local cooling passage. It becomes the other end 7b.

The cooling water supply pipe 4 is arranged eccentrically in the first cooling passage 3, and is located on the left side of the partition wall 11 in the drawing so that the opening thereof faces the one end 7 a of the local cooling passage 7. .

The other structure is the same as that of the first embodiment, and a detailed description is omitted.

In the above configuration, the cooling water from the cooling water supply source 5 is jetted from the opening of the cooling water supply pipe 4, and at this time, the opening of the cooling water supply pipe 4 is connected to one end 7 a of the local cooling passage 7. Most of the cooling water enters the local cooling passage 7 from one end 7a because it is partitioned by the partition wall 11 so as to face with a rough gap. The cooling water that has entered the local cooling passage 7 from the one end 7a flows from the forward path 7c to the turn-back part 7d, further from the turn-back part 7d to the return path 7e, and cools the columnar part 2 during this process.

Next, a large amount of cooling water flows from the return path portion 7e to the first cooling passage 3 via the other end portion 7b, and merges with the cooling water that has not entered the local cooling passage 7, where the inside of the mold 1 is formed. Is cooled and further reaches a cooling water discharge source 6 to be discharged.

In this embodiment, the local cooling passage 7 has a bottomed hole 10 formed in the columnar portion 2 and a section of the bottomed hole 10 which is inserted halfway through the bottomed hole 10. Since the partition wall 11 is divided into two parts, when the local cooling passage 7 is processed, only one bottomed hole 10 needs to be formed in the mold 1. Also, as shown in the application examples of FIGS. 9 and 10, by forming a bottomed hole so that the wall thickness of the mold becomes constant, the temperature distribution of the mold is made uniform to reduce the thermal stress. With such a configuration in which the thermal stress is reduced, failures such as mold cracking can be reduced.

(Fifth Embodiment) Next, a fifth embodiment of the present invention will be described with reference to FIGS. 11 and 12. In the fifth embodiment, the cooling water supply pipe is fixed. The other features are the same as those of the first embodiment. Hereinafter, the differences will be mainly described.

In FIG. 11, the cooling water supply pipe 4 disposed in the first cooling passage 3 is fixedly disposed in the cooling passage by a fixing member 12. The fixing member is made of, for example, brass, has a substantially triangular shape as shown in the cross-sectional view of FIG. 12, and is fixed to a central portion thereof by brazing or the like. Other parts are the same as those of the first embodiment, and the description thereof will be omitted.

In this embodiment, since the cooling water supply pipe 4 in the first cooling passage 3 is positioned and fixed by the fixing member, the accuracy of the position of the cooling water supply pipe is improved, and the variation in cooling capacity can be reduced. is there.

(Sixth Embodiment) Next, a sixth embodiment of the present invention will be described with reference to FIG. 13. This embodiment is different from the first embodiment in the shape of the local cooling passage. Hereinafter, the differences will be mainly described.

In the figure, a local cooling passage 7 formed inside a columnar portion 2 constituting a cavity surface is open at one end 7a and the other end 7b at the end of the first cooling passage 3.
A forward path 7c is formed from one end 7a, and a return path 7e is formed parallel to the inside of the column 2 from the other end 7b. The forward path 7c and the return path 7e communicate with each other at a turnback 7d. Other configurations are the same as those of the first embodiment, and a specific description will be omitted.

In this embodiment, since the forward path 7c and the return path 7e of the local cooling passage 7 are formed in parallel, when the local cooling passage 7 is processed, it can be easily formed by electric discharge machining or the like. It is. The folded portion 7d can also be formed relatively easily due to the lateral harshness of electric discharge machining.

Further, in this embodiment, since the local cooling passage 7 is not installed diagonally, there is an advantage that the local cooling passage 7 can be installed even in a thinner columnar portion.

[0047]

As described above, according to the present invention,
A local cooling structure for a mold including a local cooling passage that enters a convex portion that forms a cavity surface of the mold and has a folded portion in the convex portion, and a cooling water supply source that supplies cooling water to the local cooling passage. Therefore, the mold having the complicated cavity shape can be effectively cooled, and the cooling passage can be prevented from being blocked, so that the reliability of the cooling function can be improved.

[Brief description of the drawings]

FIG. 1 is a schematic longitudinal sectional view showing a local cooling structure of a mold according to a first embodiment of the present invention.

FIG. 2 is a schematic longitudinal sectional view showing a local cooling structure of a mold according to a second embodiment of the present invention.

FIG. 3 is a schematic longitudinal sectional view showing a local cooling structure of a mold according to a third embodiment of the present invention.

FIG. 4 is a plan view showing an application example in the third embodiment of the present invention.

FIG. 5 is a schematic longitudinal sectional view showing an application example in the third embodiment of the present invention.

FIG. 6 is a plan view showing another application example of the third embodiment of the present invention.

FIG. 7 is a schematic longitudinal sectional view showing another application example in the third embodiment of the present invention.

FIG. 8 is a schematic longitudinal sectional view showing a local cooling structure of a mold according to a fourth embodiment of the present invention.

FIG. 9 is a plan view showing an application example of the fourth embodiment of the present invention.

FIG. 10 is a longitudinal sectional view showing an application example in the fourth embodiment of the present invention.

FIG. 11 is a schematic longitudinal sectional view showing a local cooling structure of a mold according to a fifth embodiment of the present invention.

FIG. 12 is a sectional view taken along the line BB in FIG. 5;

FIG. 13 is a schematic longitudinal sectional view showing a local cooling structure of a mold according to a sixth embodiment of the present invention.

FIG. 14 is a schematic longitudinal sectional view showing a cooling structure of a mold according to the related art.

FIG. 15 is a view showing a step of cooling a columnar portion of a mold from the outside in a conventional technique.

FIG. 16 is a schematic longitudinal sectional view showing a local cooling structure of a mold according to the related art.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Die 2 ... Columnar part (convex part) 3 ... 1st cooling path 4 ... Cooling water supply pipe 5 ... Cooling water supply source 6 ... Cooling water discharge source 7. ..Local cooling passages, 7a ... one end, 7b ...
The other end, 7c: forward section, 7d: folded section, 7
e: return path portion 8: second cooling passage 9 ... third cooling passage 10: bottomed hole 11: partition wall 12: fixing member

Claims (7)

[Claims] 1. A local cooling passage which enters a convex portion forming a cavity surface of a mold and has a folded portion in the convex portion, and a cooling water supply source communicating with one end of the local cooling passage. Local cooling structure of the mold. 2. The mold according to claim 1, wherein the local cooling passage is a substantially V-shaped hole having a vertical cross section formed in a convex portion forming a cavity surface of the mold. Cooling structure. 3. The cooling water supply pipe according to claim 1, wherein both ends of the local cooling passage communicate with a first cooling passage in which a cooling water supply pipe communicating with the cooling water supply source is disposed. Wherein the opening is disposed in the first cooling passage so that the opening faces one end of the local cooling passage. 4. The cooling water supply pipe according to claim 1, wherein both ends of the local cooling passage communicate with a cooling water supply pipe communicating with the cooling water supply source inside a first cooling passage disposed therein. A local cooling structure for a mold, wherein an opening thereof is bent so as to face one end of the local cooling passage. 5. The cooling water passage according to claim 1, wherein one end of the local cooling passage communicates with a second cooling passage communicating with the cooling water supply source, and the other end of the local cooling passage communicates with a cooling water discharge source. A local cooling structure for a mold, which communicates with a third cooling passage. 6. The cross section of claim 1, wherein the local cooling passage is provided with a bottomed hole formed in the projection, and is partially inserted into the bottomed hole, and a cross section of the bottomed hole at the inserted portion. And a partition wall for dividing the mold into two parts. 7. The local cooling structure of a mold according to claim 4, wherein the supply pipe is fixedly supported.