JP3176429B2 - Sub-zero processing method for press dies - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sub-zero treatment method for a press die in which a build-up welding material joined to the edge of the press die is cooled and hardened with dry ice.

[0002]

2. Description of the Related Art Among press dies, for example, a trimming die for cutting a plate-like work into a predetermined shape is provided with a high-hardness trimming blade at an edge portion thereof. Conventionally, such a trimming blade has been formed by quenching the edge portion of a trimming mold, but this method does not provide the trimming blade with a desired hardness, or causes inconveniences such as burning cracks. was there.

[0003] Accordingly, the present applicant has filed Japanese Patent Application No. Hei 3-3127.
No. 66 proposes a method for manufacturing a press die as shown in FIG.

That is, as shown in FIG. 5A, a chamfered portion 2 is formed by removing an edge portion of a trimming mold 1, and subsequently, as shown in FIG. A predetermined overlay welding material 3 is overlaid and welded three times. The build-up welding material 3 has a martensite transformation start temperature of about 0 ° C. to about 150 ° C., and most of the austenite in the structure remains without transforming to martensite, and has a hardness of HRC45. Smaller and easier to machine.

[0005] Next, as shown in FIG. 5 (c), after machining is performed so that the overlay welding material 3 has a trimming blade 4 shape, as shown in FIG. 3
The cooling frame 5 is fixed by temporary welding so as to cover the outer periphery of
A so-called sub-zero treatment is performed in which the inside is filled with a coolant such as dry ice 6 to cool the overlay welding material 3.
By this sub-zero treatment, austenite in the structure of the build-up welding material 3 is transformed into martensite, and as a result, the hardness of the build-up welding material 3 is hardened so as to exceed HRC45 to form the trimming blade 4 having sufficient hardness. Is done.

[0006]

However, in the above-mentioned conventional method, it is only necessary to manufacture the cooling frame 5 for performing the sub-zero treatment on the overlay welding material 3 according to the shape of each trimming mold 1. In addition, since the cooling frame 5 needs to be fixed to the trimming mold 1 by temporary welding, there is a problem that both the cost and the working time increase.

The present invention has been made in view of the above circumstances, and has as its object to provide a method for performing sub-zero processing of a press die at low cost and in a short time.

[0008]

In order to achieve the above object, the present invention provides a sub-zero treatment method for a press die in which a build-up welding material joined to the edge of the press die is cooled and hardened with dry ice. A step of joining the two longitudinal edges of the strip-shaped flexible sheet to each other to form a pipe-shaped container; a step of enclosing dry ice inside the pipe-shaped container; A step of separating the both side edges from each other and joining to a press die so as to cover the edge portion, and bringing dry ice into contact with a build-up welding material.

The present invention also relates to a method for sub-zero treatment of a press die, wherein the build-up welding material joined to the edge of the press die is cooled and hardened with dry ice. Forming a pipe-shaped container that covers the edge portion by joining to a press die, and a step of sealing dry ice inside the pipe-shaped container and bringing the same into contact with a build-up welding material. 2.

The present invention has a third feature in that, in addition to the first or second feature, a pair of rubber magnets are fixed along both longitudinal edges of the strip-shaped flexible sheet. .

[0011] In addition to the above first or second feature, the present invention further comprises connecting the pipe-shaped container to a liquefied carbon dioxide cylinder to seal dry ice inside the pipe-shaped container. 4.

[0012]

Embodiments of the present invention will be described below with reference to the drawings.

FIGS. 1 to 4 show a first embodiment of the present invention. FIG. 1 is a view showing an expanded state of a flexible sheet, and FIG. 2 shows a pipe-shaped container formed from the flexible sheet of FIG. FIG. 3 is a sectional view taken along line 3-3 of FIG. 2, and FIG. 4 is a sectional view showing a state where the pipe-shaped container is mounted on a trimming mold.

As shown in FIGS. 1 and 2, a flexible sheet 1 is formed by cutting aluminum wool that can transmit air into a strip.
1 is provided with a pair of flexible rubber magnets 12 and 12 fixed along both longitudinal edges thereof. The flexible sheet 11 forms a pipe-shaped container 13 by bending the flexible sheet 11 in the direction of the arrow A in FIG. On the inner surface of one end of the flexible sheet 11, surface tapes 14, 15 such as Velcro (registered trademark) are attached.
4 and 15 are joined together to form a pipe-shaped container 1
3 is closed at one end. A connecting member 16 made of a flexible synthetic resin is fixed to the other end of the flexible sheet 11. In a state where the flexible sheet 11 is bent to form a pipe-shaped container 13, the connecting member 16 is And connected to a hose described later.

Next, the operation of the embodiment of the present invention having the above configuration will be described.

As shown in FIG. 2 and FIG.
1 is rolled into a cylindrical shape, and a pair of rubber magnets 12, 12 are attracted to each other to form a pipe-shaped container 13.
3. A joint member 1 provided at the tip of a hose 18 extending from a liquefied carbon dioxide cylinder 17 inside a connecting member 16 at the other end of
Insert 9 and fix with band 20 from outside. When the valve 21 provided on the hose 18 is opened from this state, the carbon dioxide gas is supplied from the liquefied carbon dioxide cylinder 17 into the pipe-shaped container 13. At this time, the inside of the pipe-shaped container 13 made of aluminum wool is expelled to allow gas to freely permeate, and the inside of the pipe-shaped container 13 is filled with snow-like dry ice 6 formed by sublimation of carbon dioxide gas. .

Subsequently, the pipe-shaped container 13 filled with the dry ice 6 is removed from the hose 18 to separate the pair of rubber magnets 12 from each other,
After the separation, the dry ice 6 held in the pipe-shaped container 13 is removed by adsorbing the pair of rubber magnets 12 along the edge of the trimming mold 1 as shown in FIG. It is brought into contact with the build-up welding material 3 which has been machined. As a result, the build-up welding material 3 is cooled by the dry ice 6, its hardness is increased, and the trimming blade 4 is formed. At this time, since the pipe-shaped container 13 made of aluminum wool has extremely high heat insulating properties, a sufficient cooling effect can be obtained with a small amount of dry ice 6.

Since the pipe-shaped container 13 has flexibility, it can be applied not only to various trimming molds 1 having different shapes but also to repeated use. Extremely economical. In addition, the use of the rubber magnets 12,
Can be formed and attached to and detached from the trimming mold 1 in an extremely short time, and the working time can be reduced. Further, since the pipe-shaped container 13 is connected to the liquefied carbon dioxide cylinder 17 to fill the inside thereof with the snow-like dry ice 6, the forming operation and the filling operation of the dry ice 6 are completed at the same time to improve the work efficiency. be able to.

In the first embodiment, after the inside of the previously formed pipe-shaped container 13 is filled with dry ice 6, this pipe-shaped container 13 is joined to the trimming mold 1. As an embodiment, the following method can be adopted.

That is, as shown in FIG.
Is joined to the trimming mold 1 by rubber magnets 12, 12 to form a pipe-shaped container 13. Then, dry ice 6 is filled in the pipe-shaped container 13 from a liquefied carbon dioxide cylinder 17 to build up the welding material 3. Can be cooled.

Although the embodiments of the present invention have been described in detail, the present invention is not limited to the above embodiments, and various small design changes can be made.

For example, in the embodiment, the trimming mold is illustrated, but the present invention can be applied to other press molds such as a bending mold. Further, other means such as an adhesive tape can be used instead of the rubber magnet. Further, the dry ice does not necessarily need to be supplied from the liquefied carbon dioxide cylinder 17, and it is also possible to push the crushed dry ice into the inside of the pipe-shaped container to fill it.

[0023]

As described above, according to the first feature or the second feature of the present invention, various types of pipe-shaped containers formed of a flexible sheet capable of holding dry ice therein are flexed. Since it is attached to the edge of a press die with a shape, it is possible to apply a common flexible sheet to the sub-zero processing of multiple press dies without manufacturing a dedicated cooling frame for each press die Can be saved, and the time required for manufacturing and temporarily welding the cooling frame can be saved, and the working time can be greatly reduced.

According to the third aspect of the present invention, since a pair of rubber magnets are fixed along both longitudinal edges of the flexible sheet, the rubber magnets are attracted to each other to form a pipe-shaped container. Alternatively, the pipe-shaped container can be adsorbed to the press die by a rubber magnet, thereby further reducing the working time.

According to the fourth feature of the present invention, since the pipe-shaped container is connected to the liquefied carbon dioxide cylinder and the dry ice is sealed therein, the dry ice forming operation and the sealing operation are performed simultaneously, thereby improving the work efficiency. Can be improved.

[Brief description of the drawings]

FIG. 1 is a diagram showing an expanded state of a flexible sheet.

FIG. 2 is a view showing a pipe-shaped container formed from a flexible sheet.

FIG. 3 is a sectional view taken along line 3-3 in FIG. 2;

FIG. 4 is a sectional view showing a state where the pipe-shaped container is mounted on a trimming mold.

FIG. 5 is a diagram showing a conventional sub-zero process.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 trimming mold (press mold) 3 overlay welding material 6 dry ice 11 flexible sheet 12 rubber magnet 13 pipe-shaped container 17 liquefied carbon dioxide cylinder

Continuation of the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) C21D 1/18 C21D 9/00 C21D 9/50 101 B21D 37/20 B23K 31/00

Claims (4)

(57) [Claims] 1. A sub-zero processing method for a press die, wherein a build-up welding material (3) joined to an edge of the press die (1) is cooled and hardened with dry ice (6). A step of forming a pipe-shaped container (13) by joining both longitudinal edges of the sheet (11) to each other, a step of sealing dry ice (6) inside the pipe-shaped container (13), A step of separating the two longitudinal edges of the conductive sheet (11) from each other, joining the two to the press die (1) so as to cover the edges, and bringing the dry ice (6) into contact with the overlay welding material (3). Characterized by having
Sub-zero processing method for press dies. 2. A sub-zero processing method for a press die, wherein a build-up welding material (3) joined to an edge of the press die (1) is cooled and hardened by dry ice (6). A step of joining both longitudinal edges of the sheet (11) to the press die (1) to form a pipe-shaped container (13) covering the edge portion, and the pipe-shaped container (13)
Enclosing dry ice (6) inside and contacting the build-up welding material (3).
Sub-zero processing method for press dies. 3. The press die according to claim 1, wherein a pair of rubber magnets (12) are fixed along both longitudinal edges of the strip-shaped flexible sheet (11). Sub-zero processing method. 4. The pipe-shaped container (13) is connected to a liquefied carbon dioxide cylinder (17) so as to seal dry ice (6) inside the pipe-shaped container (13). 3. The sub-zero treatment method for a press die according to claim 1 or 2.