JPH04220151A - Method for making mold - Google Patents

Abstract

PURPOSE:To simplify the work of setting plural pieces of chiller components in the forming die for making the mold. CONSTITUTION:The holding component 14 A which holds plural chiller components in the prescribed arranging state freely attachable and detachable is prepared, and plural chiller components are set in the forming die for making the mold in the state being held with the holding components 14A. Then, the chiller components 10A is separated from the holding components 14A, and only the holding components 14A are taken out from the forming die for making the mold. Then, the casting sand is filled in the forming die for making mold, the casting sand is hardened.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mold making method for filling a molding mold with foundry sand to create a mold made of foundry sand.

0002

2. Description of the Related Art Some cast products require rapid cooling and chilling of predetermined portions of the cast product.

Therefore, as shown in Japanese Patent Application Laid-Open No. 61-78548, a permanent mold with high thermal conductivity is used for the part of the cast product that corresponds to the part to be chilled, and a permanent mold is used for the part of the cast product that is not to be chilled. A casting method that uses a permanent mold with low thermal conductivity in the part to be chilled, or a chiller member is placed in a part corresponding to the part to be chilled in the cast product, and the chiller member absorbs heat to chill the part of the cast product. Casting methods with rapid cooling are known.

[0004] When adopting the latter casting method, it is necessary to place a chiller member in advance at a location corresponding to the chilled portion of the cast product in the mold, so the chiller member is set at a predetermined position in the mold for molding. After that, the mold is filled with molding sand, and the mold is hardened to form a mold.

[0005]

[Problem to be Solved by the Invention] However, in the case of the above casting method, the chiller member must be placed at a predetermined position within the mold for production; The task of doing so is not easy. Particularly, when setting a plurality of chiller members at predetermined positions within a mold, setting the chiller members becomes a difficult task.

In view of the above, it is an object of the present invention to simplify the work of setting a plurality of chiller members in a mold.

[0007]

[Means for Solving the Problems] In order to achieve the above object, the inventions of claims 1 and 2 provide a holding member that removably holds a plurality of chiller members in a predetermined arrangement state, and The member is set in a mold while being held by the holding member.

Specifically, the solution taken by the invention of claim 1 includes a plurality of chiller members for rapidly cooling a predetermined portion of a cast product, and a plurality of chiller members that are detachably held in a predetermined arrangement state. A holding member is prepared, and the plurality of chiller members are set in a molding mold while being held by the holding member, and then the chiller member and the holding member are separated and only the holding member is placed in the mold. The mold is taken out of the mold, and then molding sand is filled into the mold and the molding sand is hardened.

Further, specifically, the solution taken by the invention of claim 2 includes a plurality of chiller members for rapidly cooling a predetermined portion of a cast product, and a plurality of chiller members that are freely attachable and detachable in a predetermined arrangement state. After preparing a holding member for holding the chiller member and setting the plurality of chiller members held in the holding member in a mold for molding, filling the mold for molding with molding sand, and then, The chiller member and the holding member are separated, only the holding member is taken out of the molding mold, and then the molding sand in the molding mold is hardened.

0010

[Operation] According to the structures of claims 1 and 2, a holding member that removably holds a plurality of chiller members in a predetermined arrangement state is prepared, and a mold for molding is provided with a plurality of chiller members held by the holding member. Since the chiller members are set inside, a plurality of chiller members can be set at the same time.

[0011] Furthermore, after the chiller member and the holding member are separated and only the holding member is taken out of the molding mold, the molding mold is filled with molding sand and the molding sand is hardened. There is no holding member inside the molding sand, that is, the mold.

0012

Embodiments Hereinafter, embodiments of the present invention will be explained based on the drawings.

[0013] Although the present invention does not particularly limit the type of cast product, in the following examples, a method for manufacturing a mold for casting a camshaft of an engine will be explained.

1 and 2 show a mold making method according to a first embodiment of the present invention, in which 10A and 10A indicate the length of the camshaft in order to rapidly cool a predetermined portion of the cam of the camshaft (not shown). Each chiller member 10 is a rectangular plate-shaped chiller member arranged at predetermined intervals in the direction.
A has substantially circular notches 12 that are open at each side end surface on both left and right sides of the upper part.

Further, in the figure, reference numerals 14A and 14A are round bar-shaped holding members that extend in the length direction of the camshaft and have a diameter one size larger than the diameter of the circular notch 12. A holding portion 16 having a substantially rectangular cross section is provided at a portion corresponding to each chiller member 10A disposed at a predetermined position in the longitudinal direction of the camshaft. and,
As shown in FIG. 2(a), the height of the holding portion 16 is slightly smaller than the height of the opening of the circular notch 12 of the chiller member 10A, and the width of the holding portion 16 is the diameter of the circular notch 12. Both end surfaces of the holding portion 16 in the width direction are formed into curved surfaces corresponding to the inner surface of the circular notch portion 12 .

[0016] As a result, the holding portion 16 of the holding member 14A
is insertable into the circular notch 12 and rotatable within the circular notch 12 . Moreover, when the holding member 14A is rotated approximately 90 degrees after insertion, each chiller member 10A is held in a predetermined arrangement state by the holding member 14A.

[0017] Hereinafter, a method of molding a mold using the above chiller member 10A and holding member 14A will be explained.

First, after arranging each chiller member 10A at a predetermined position in the length direction of the camshaft, as shown in FIGS. 1 and 2(a),
As shown in the figure, the circular notch 12 of each chiller member 10A
Insert the holding portion 16 of the holding member 14A into the holding member 14A. Next, Figure 2
As shown in (b), the holding member 14A is rotated approximately 90 degrees, and each chiller member 10A is held by the holding portion 16 thereof.

Next, each chiller member 10A is attached to the holding member 14.
Set it in the mold while holding it in A. After that, the holding member 14A is rotated about 90 degrees again to hold the holding part 1.
6 is removed from the circular notch 12, and then the holding member 14 is removed.
Take A out of the mold. By doing so, each chiller member 10A can be easily set at a predetermined position within the mold.

Next, after filling the cavity of the molding mold with molding sand, the molding sand is hardened to form a mold.

FIGS. 3 and 4 show a mold making method according to a second embodiment of the present invention, in which reference numerals 10B and 10B are horseshoe-shaped cams for rapidly cooling a predetermined portion of the cam of the camshaft, as described above. A chiller member, each chiller member 1
0B has a protrusion 18 projecting downward on the lower end surface.

Further, in the figure, 14B is a rectangular plate-shaped holding member extending in the length direction of the camshaft, and the holding member 14B has a width slightly larger than the width of the camshaft at its center. A rectangular notch 20 extending in the length direction of the camshaft is provided, and a protrusion 1 is provided at a location corresponding to the protrusion 18 of the chiller member 10B.
A cutout recess 22 having a shape slightly larger than the outer shape of the cutout 8 is provided.

A method of molding a mold using the chiller member 10B and holding member 14B described above will be explained below.

First, each chiller member 10B is placed on the upper surface of the holding member 14B and held by the holding member 14B so that the protrusion 18 of the chiller member 10B is inserted into the cutout recess 22 of the holding member 14B.

Next, as shown in FIG. 3, the camshaft is held inside a molding mold consisting of a mold 24 having a protrusion 24a having the same shape as the upper part of the camshaft, and a frame 26 as shown in FIG. After setting the chiller member 10B held by the member 14B, molding sand is filled into the inside of the mold, and then the molding sand is hardened to form an upper mold 28 as a mold.

Next, a lower mold 32 is molded using a mold (not shown) having a protrusion having the same shape as the lower part of the camshaft and a frame 30 as shown in FIG. The upper mold 28 is placed on top of the mold 32. After that, the upper mold 28 and the lower mold 3
Molten metal is injected into the cavity formed by 2 to obtain a cast product.

Next, after separating the upper mold 28 and the lower mold 32 and opening the molds, the holding member 14B is removed from the upper mold 28.

In the second embodiment, the holding member 14B was separated from the upper mold 28 after casting, but instead of this, the holding member 14B was separated from the upper mold 28 after the upper mold 28 was molded. Thereafter, the upper mold 28 may be placed on the lower mold 32, and the molten metal may be poured into the cavity formed by the upper mold 28.

FIG. 5 shows a modification of the chiller members 14A and 14B used in the first and second embodiments. The chiller member 14C according to this modification has a curved notch on both sides, thereby forming an upward slope 36 and a downward slope 38 on both sides of the chiller member 14C.

Therefore, if the upward slope 36 and the downward slope 38 are not provided on both sides of the chiller member 14C, the difference in the stress distribution in the sand that occurs during molding as shown in FIGS. 6(a) and 6(b). The chiller member b may be displaced from the camshaft c within the upper die a due to
As shown in (d), when separating the upper mold a and the camshaft c after casting, the chiller member b may fall from the upper mold a due to gravity. However, as described above, if the upward slope 36 and the downward slope 38 are provided on both sides of the chiller member 14C, even if there is a difference in the stress distribution in the sand during molding, the upward slope 36 of the chiller member 14C will not be affected by the casting sand. Since the chiller member b is pressed downward, it does not shift from the camshaft c, and even if the chiller member b is subjected to gravity, the downward slope 38 is pressed upward by the casting sand, so the chiller member b Never fall.

[0031]

As explained above, according to the casting mold manufacturing method according to the invention of claims 1 and 2, since a plurality of chiller members are set in a mold for molding while being held by a holding member, Since a plurality of chiller members can be set at the same time, even if there are a plurality of chiller members, the work of setting the chiller members is extremely easy.

[0032] Furthermore, after separating the chiller member and the holding member and taking only the holding member out of the mold, the molding sand is held inside the obtained mold in order to harden the molding sand in the mold. Since there are no members, the holding member will not be deformed or damaged even if the mold is broken when removing the cast product.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing a state in which a chiller member is held by a holding member in a first embodiment of the present invention.

FIG. 2 is a sectional view showing a state in which the holding portion of the holding member is inserted into the circular notch of the chiller member in the first embodiment.

FIG. 3 is a perspective view showing a state in which a holding member is set in a mold in a second embodiment of the present invention.

FIG. 4 is a sectional view showing a chiller member and a holding member arranged between an upper mold and a lower mold in the second embodiment.

FIG. 5 is a sectional view showing a modification of the chiller member used in the first and second embodiments.

FIG. 6 is a sectional view showing problems when using a conventional chiller member.

[Explanation of symbols]

10A, 10B...Chiller member 12...Circular notch 14A, 14B...holding member 16...Holding part

Claims (2)

[Claims] 1. Prepare a plurality of chiller members for rapidly cooling a predetermined portion of a cast product, and a holding member that detachably holds the plurality of chiller members in a predetermined arrangement state,
The plurality of chiller members are set in a molding mold while being held by the holding member, and then the chiller member and the holding member are separated and only the holding member is taken out of the molding mold. A method for making a mold, comprising: thereafter filling the mold with foundry sand and hardening the foundry sand. 2. A plurality of chiller members for rapidly cooling a predetermined portion of a cast product and a holding member for detachably holding the plurality of chiller members in a predetermined arrangement state are prepared, and the plurality of chiller members are is held in the holding member, and then the mold is filled with molding sand.Then, the chiller member and the holding member are separated and only the holding member is left. A mold making method, characterized in that the molding sand is taken out of the mold for molding, and then the molding sand in the mold for molding is hardened.