JP2001105096A - Metallic mold for casting - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a technique, in which the development of crack in a metallic mold caused by heat stress can be prevented. SOLUTION: The metallic mold 12 for casting is the one cooling a sprue bottom easily damaged with molten metal, with a meandering cooling water passage at more intensely than the other part, and a part of the metallic mold for casting is formed as a removable cover, and a position for holding the cover or the meandering cooling water passage on the back surface of the cover is formed so as to overlook the meandering cooling water passage from the outside by removing the cover. In this way, a large quantity of the heats in the metallic mold can be absorbed from the wall surface of the meandering cooling water passages at the right and the left sides.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a casting mold having a cooling water passage.

[0002]

2. Description of the Related Art A casting mold is a method in which a fixed mold and a movable mold are clamped to form a cavity, and a molten metal is filled in the cavity to produce a cast product. A cooling water passage through which cooling water flows to maintain the temperature of the cooling water at an appropriate temperature. As a casting mold having a cooling water passage, for example, a "casting mold" disclosed in Japanese Patent Application Laid-Open No. 8-174147 is known. This technique will be described in detail with reference to the following drawings.

FIG. 9 is a plan view showing a movable mold of a conventional casting mold. The movable mold 100 is provided on the opposite surface 1 of the fixed mold.
A sprue 101 is formed at 00a, and left and right runners 102 and 103 are extended from the spout 101 to the left and right.
Extend the left and right weirs 104 and 105 from 103 upward,
Left and right cavity walls 10 and 105 on left and right weirs 104 and 105, respectively.
6, 107, and a cooling water passage 108 is formed. As shown by the arrow a, the molten metal enters the left and right cavity walls 106 and 107 through the left and right runners 102 and 103 → the right and left weirs 104 and 105.

[0004] The cooling water passage 108 is connected to the left and right runners 1.
., Which are linearly formed along lines 02 and 103, and vertical cooling water passages 108b which are linearly formed along the gate 101.
By flowing the cooling water through the horizontal cooling water passages 108a,... → the vertical cooling water passages 108b, as shown by the arrow b, the heat of the mold is absorbed by the cooling water to cool the mold.

[0005]

The movable mold 1
In order to cool 00 more strongly, the wall area of the cooling water passage (that is, the heat radiation area) may be increased, and the heat of the mold may be efficiently absorbed by the cooling water. In order to increase the wall area of the cooling water passage, it is conceivable to increase the number of cooling water passages 108 as an example.

However, it is difficult to form a large number of cooling water passages in a limited portion of the movable mold 100. In particular, it is more difficult to increase the number of cooling water passages when drilling the cooling water passage. For this reason, there is a limitation in increasing the wall area of the cooling water passage 108, and the heat of the movable mold 100 may not be efficiently absorbed in some cases. In this case, it takes a relatively long time to lower the temperature of the movable mold 100 to an appropriate temperature. Hereinafter, the cooling state of the movable mold 100 will be described with reference to a graph shown in the following figure.

FIG. 10 is a graph illustrating the temperature of a conventional casting mold in relation to the casting process. The vertical axis indicates the mold temperature (° C.), and the horizontal axis indicates time (second). The temperature of the mold was measured by a temperature sensor 110 (shown in FIG. 9). 1
Second casting step: The mold is clamped while cooling water is flowing through the cooling water passage to fill the cavity with molten metal. The temperature of the mold rises to 150 ° C. due to the heat of the molten metal. After the molten metal in the cavity solidifies, the mold is opened and the cast product is taken out.
At this time, the temperature of the mold can be reduced only to 110 ° C.

Second casting step: The mold is clamped to fill the cavity with molten metal. At this time, the temperature of the mold rises to 170 ° C. due to the heat of the molten metal. This temperature is higher than the temperature of the first casting step (150 ° C.). After the molten metal in the cavity solidifies, the mold is opened and the cast product is taken out. The temperature of the mold at this time is 130 ° C., which is higher than the temperature (110 ° C.) of the first casting step.

As described above, since the temperature of the mold can be reduced only to 110 ° C. in the first casting process, the temperature of the mold gradually increases every time the casting process is repeated. Therefore, a relatively large thermal stress may be generated in the mold, and a crack (crack) may be generated in the mold.

Accordingly, an object of the present invention is to provide a technique capable of preventing a mold from being cracked by thermal stress.

[0011]

Means for Solving the Problems To achieve the above object, a first aspect of the present invention is to cool a gate bottom, which is easily damaged by molten metal, with a meandering cooling water passage more strongly than other parts. A casting mold, in which a part of the casting mold is set as a removable lid, and the meandering cooling water passage is formed in a portion for storing the lid or a back surface of the lid, and the lid is removed. The meandering cooling water passage can be viewed from the outside.

[0012] A cooling water passage is formed in a portion for housing the lid or on the back surface of the lid. Therefore, since the cooling water passage can be formed at a portion that can be seen from the outside by removing the lid, the cooling water passage can be formed in a complicated shape with a meandering shape. By meandering the cooling water passage, the wall area of the cooling water passage can be increased. Therefore, a large amount of heat of the mold can be absorbed from the meandering wall surface of the cooling water passage, so that thermal stress generated in the mold can be suppressed.

[0013]

Embodiments of the present invention will be described below with reference to the accompanying drawings. The drawings should be viewed in the direction of reference numerals. FIG. 1 is a side view of a casting apparatus to which a casting mold according to the present invention is attached. The casting apparatus 10 includes a base 11
And a mold matching cylinder 18 for clamping and opening the casting mold 12. The casting mold 12 includes a fixed mold 14 attached to the base 11 and a movable mold 20 movable along a guide rod 17.

The fixed die 14 includes a fixed die mounting plate 15 mounted on the base 11 and a fixed die 16 mounted on the fixed die mounting plate 15. The movable mold 20 includes a movable mold mounting plate 21 movably mounted on the base 11 along the guide rod 17, and a movable mold 22 mounted on the movable mold mounting plate 21. The mold matching cylinder 18 has a cylinder 18a attached to a support member 19 and a cylinder rod 18b.
Is mounted on a movable mold mounting plate 21 of a movable mold 20. The movable mold 22 will be described in detail with reference to the following drawings.

FIG. 2 is a view taken in the direction of the arrow 2 in FIG. Movable mold 2
2 is a surface 22a facing the fixed mold 16 (shown in FIG. 1).
The gate 23 is extended vertically in the center of the
4 extend the left and right runners 25 and 26 left and right, extend the left and right runners 27 and 28 upward from the left and right runners 25 and 26,
The cooling water passage 35 is formed inside the mold, and a temperature sensor 55 is attached to the bottom 22 b of the movable mold 22.

Gate 23, runners 25 and 26, coughs 27 and 2
The mold 8 and the cavity wall surfaces 30 and 31 are closed with the gate, runner, crest and cavity wall of the fixed mold 16 (shown in FIG. 1) by clamping the casting mold 12. It forms a cavity. Therefore, the molten metal is supplied from the gate 23 to the left and right runners 25 and 2 as shown by the arrows.
6 → It is possible to enter the left and right cavity wall surfaces 30 and 31 through the left and right weirs 27 and 28.

The cooling water passage 35 is provided at the bottom 2 of the movable mold 22.
The left and right supply cooling water passages 36 and 37 are formed, and the left and right meandering cooling water passages (serpentine cooling water passages) 40 and 41 are connected to the left and right supply cooling water passages 36 and 37, respectively. The left and right vertical cooling water passages 45 and 46 are connected to the water passages 40 and 41, and the left and right vertical cooling water passages 45 and 46 are connected.
Are connected to the left and right horizontal cooling water passages 48..., 49.

The left and right supply cooling water passages 36 and 37 are connected to a discharge port of a cooling water supply pump (not shown) via left and right supply pipes 50 and 51. The left and right vertical cooling water passages 45, 46 are passages extending vertically along the left and right sides of the gate 23, and the upper ends thereof are sealed members 47, 47.
It was closed with. Left and right horizontal cooling water passages 48
Are connected to a return port of a cooling water storage tank (not shown) via left and right return pipes 52, 53,.

Therefore, by driving the cooling water supply pump, the cooling water in the cooling water storage tank is supplied as shown by the arrow, and this cooling water is supplied to the left and right supply cooling water passages 36, 37 →
Left and right meandering cooling water passages 40, 41 → left and right vertical cooling water passages 45, 46 → left and right horizontal cooling water passages 48, 49, ...
→ It can return to the cooling water storage tank through the left and right return pipes 52, 53,.

The temperature sensor 55 is a sensor that measures the temperature in the vicinity of the gate 24 by extending the tip to the vicinity of the gate 24.

FIG. 3 is an enlarged view of a part of FIG. By arranging the left and right meandering cooling water passages 40 and 41 near the gate bottom 24, the gate bottom 24, which is easily damaged by the molten metal, is cooled more strongly than other parts.

That is, the left and right meandering cooling water passages 40, 4
By providing 1, the wall area of the cooling water passage can be increased as compared with the linear cooling water passage. Therefore, a large amount of heat of the mold is absorbed from the wall surfaces of the left and right meandering cooling water passages 40 and 41, and the gate bottom 24 can be cooled more strongly than other portions. Therefore, it is possible to suppress the thermal stress generated in the movable mold 22 and prevent the movable mold 22 from cracking due to the thermal stress.

Further, by forming the meandering cooling water passages 40 and 41, the walls of the meandering cooling water passages 40 and 41 can be made thin to have a fin shape. Therefore, the heat of the mold can be more efficiently released to the cooling water.

FIG. 4 is a sectional view taken along line 4-4 of FIG. A part of the movable mold 22 is set as a removable lid 60, and a storage recess 65 is formed in a part of the movable mold 22 for storing the lid 60, and a bottom portion of the storage recess 65 (the lid is stored). The right and left meandering cooling water grooves (meandering cooling water grooves) 6
7, 68 are formed. Cover 60 in storage recess 65
And the back surface 60 a of the lid 60 is brought into contact with the bottom 66 of the storage recess 65, so that the left and right meandering cooling water grooves 6 are formed.
The left and right meandering cooling water passages 40, 41 (see also FIG. 3) can be closed by closing the 7, 68.

Further, the lid 60 is provided with an extension 61, a groove 62 is formed in the extension 61, an O-ring 63 is attached to the groove 62, and a step 69 is formed in the storage recess 65. The gap between the lid 60 and the storage recess 65 can be sealed by the O-ring 63 by storing the lid 60 in the storage recess 65 and pressing the O-ring 63 against the step portion 69 of the storage recess 65. Therefore, it is possible to prevent the cooling water from leaking from the gap between the lid 60 and the storage recess 65.

FIG. 5 is a perspective view showing the casting mold according to the present invention with the lid removed. The cover 60 is formed in a substantially rectangular shape, and an overhang portion 61 is provided on the outer periphery of the cover 60. A groove 62 (shown in FIG. 4) is formed on the back surface 61 a of the overhang portion 61.
The ring 63 is attached, and the storage recess 65 is formed in a substantially rectangular shape corresponding to the lid 60, and left and right meandering cooling water grooves 67 and 68 are formed at the bottom 66 of the storage recess 65, and on the opening side of the storage recess 65. Step 69 with which the O-ring 63 of the extension 61 contacts
Shows a state in which is formed.

The right and left meandering cooling water grooves 67 and 68 are connected to the inlet 6
7a and 68a are connected to left and right supply cooling water passages 36 and 37, and outlets 67b and 68b are connected to left and right vertical cooling water passages 4.
5,46. Accordingly, the cooling water flows through the meandering cooling water grooves 67, 68 on one side from the inlets 67a, 68a to the outlets 67b, 68b.

By removing the lid 60 from the storage recess 65, the left and right meandering cooling water grooves (part of the meandering cooling water passage) 67, 68 can be exposed from the outside. Therefore, the meandering cooling water grooves 67, 68 having a relatively complicated shape are formed in the bottom 66 of the storage recess 65.
Can be easily processed. After processing, the lid 60 is stored in the storage recess 65 as shown by the arrow, and the left and right meandering cooling water grooves 67 and 68 are inserted into the left and right meandering cooling water passages 40 and 41 (FIG. 4).
Shown).

Next, the operation of the casting mold will be described. FIG.
(A), (b) is a 1st operation explanatory view of the casting mold | die which concerns on this invention. In (a), the movable mold 2 is moved forward by moving the cylinder rod 18b of the mold matching cylinder 18 forward.
0 is moved as shown by the arrow to clamp the casting mold 12. In (b), the molten metal is supplied to the gate 32 as shown by the arrow. The supplied molten metal flows from the gate 32 → the left and right runners →
The right and left cavities 33 enter the left and right cavities 33 (the back side is not shown).

FIG. 7 is a second operation explanatory view of the casting mold according to the present invention, and shows a cross section taken along line 7-7 in FIG. 6 (b). As described with reference to FIG. 6B, the molten metal in the gate 32 flows as shown by the arrow and reaches the bottom 24 of the gate, flows from the bottom 24 to the left and right runners 25 and 26 as shown by the arrows, and the left and right crests. Pass through and enter the left and right cavities.

On the other hand, since the cooling water supply pump is driven at the same time as the start of the casting process, the cooling water flows through the left and right supply cooling water passages 36, 37 → the right and left meandering cooling water passages 40, 41 as shown by arrows. . Here, the left and right meandering cooling water passages 4
0 and 41 meander, so that the wall area of the passage is increased. Therefore, by flowing the cooling water through the left and right meandering cooling water passages 40, 41, the left and right meandering cooling water passages 40, 4 are provided.
A large amount of heat of the mold is absorbed from the wall surface of the first die, and the gate bottom 24 can be cooled more strongly than other portions. The temperature of the gate bottom 24 is measured by the temperature sensor 55.

FIG. 8 is a diagram illustrating a third operation of the casting mold according to the present invention, and is a graph illustrating the temperature of the casting mold in relation to the casting process. The vertical axis indicates temperature (° C.), and the horizontal axis indicates time (second).

In the first casting step, the casting mold is clamped while the cooling water is flowing through the cooling water passage to fill the cavity with the molten metal. The temperature of the mold is 15 due to the heat of the molten metal.
Increase to 0 ° C. Next, after the molten metal in the cavity is solidified, the mold is opened and the cast product is taken out. By meandering a part of the cooling water passage, the temperature of the mold can be reduced to 100 ° C.

In the second casting step, the mold is clamped to fill the cavity with the molten metal. Since the temperature of the mold was lowered to 100 ° C in the first casting process,
As in the first casting step, the temperature can be suppressed to 150 ° C. Next, after the molten metal in the cavity is solidified, the mold is opened and the cast product is taken out. At this time, the temperature of the mold
As in the first casting step, the temperature can be lowered to 100 ° C.

As described above, even if the casting step is repeated a plurality of times, the temperature of the mold can be maintained at the predetermined temperature, so that a large thermal stress can be prevented from being generated in the mold.
For this reason, it is possible to prevent the mold from cracking due to the thermal stress generated in the casting process.

In the above embodiment, the left and right meandering cooling water grooves 67 and 68 are formed in the bottom 66 of the storage recess 65. However, the present invention is not limited to this. A cooling water groove may be formed. Further, the left and right meandering cooling water passages 40 and 4 are provided in the cooling water passage 35 of the movable mold 22.
Although the example in which 1 is formed has been described, the right and left meandering cooling water passages may be formed in the cooling water passage to the fixed mold 16. Further, the example in which the left and right meandering cooling water passages 40 and 41 are formed near the gate bottom 24 has been described, but the left and right meandering cooling water passages 40 and 41 may be formed at other locations.

[0037]

According to the present invention, the following effects are exhibited by the above configuration. According to the first aspect of the present invention, the cooling water passage is formed in a portion for storing the lid or a back surface of the lid, so that the cooling water passage can be formed in a portion that can be exposed from the outside by removing the lid. Therefore, since the cooling water passage can be formed in a complicated shape meandering, the wall area of the cooling water passage (that is, the heat radiation area) can be increased.

Therefore, the mold can be sufficiently cooled by absorbing a large amount of heat of the mold from the meandering wall surface of the cooling water passage, so that the thermal stress generated in the mold can be suppressed. As a result, the occurrence of cracks in the mold due to thermal stress can be prevented, so that the repair work of the mold can be simplified and the operating rate of the mold can be increased.

[Brief description of the drawings]

FIG. 1 is a side view of a casting apparatus equipped with a casting mold according to the present invention.

FIG. 2 is a view taken in the direction of arrow 2 in FIG. 1;

FIG. 3 is an enlarged view of a part of FIG. 2;

FIG. 4 is a sectional view taken along line 4-4 in FIG. 3;

FIG. 5 is a perspective view showing a state in which a lid of the casting mold according to the present invention is removed.

FIG. 6 is an explanatory view of a first operation of the casting mold according to the present invention.

FIG. 7 is an explanatory view of a second operation of the casting mold according to the present invention.

FIG. 8 is an explanatory view of a third operation of the casting mold according to the present invention.

FIG. 9 is a plan view showing a movable mold of a conventional casting mold.

FIG. 10 is a graph illustrating the temperature of a conventional casting mold in relation to the casting process.

[Explanation of symbols]

12: casting mold, 22: movable mold, 24: gate bottom, 3
5: cooling water passage, 40: meandering cooling water passage (left side meandering cooling water passage), 41: meandering cooling water passage (right side meandering cooling water passage), 60: lid, 66: site for storing lid (storage recess) Bottom part), 67... Meandering cooling water groove, 68.

 ──────────────────────────────────────────────────続 き Continuation of front page (72) Inventor Hiroshi Ichikawa 1-10-1 Shinsayama, Sayama-shi, Saitama Honda Engineering Co., Ltd. F term (reference) 4E093 NB05

Claims (1)

[Claims] 1. A casting mold in which a sprue bottom, which is easily damaged by molten metal, is cooled more strongly than other parts by a meandering cooling water passage, and a part of the casting mold can be removed. Casting, characterized in that the meandering cooling water passage is formed at the site for housing the cover or on the back surface of the cover, and the meandering cooling water passage is exposed from the outside by removing the cover. Mold.