JPS62118963A - Casting method for casting - Google Patents

Abstract

PURPOSE:To make the structure of an unsolidified part higher in density and more uniform and to prevent the generation of shrinkage cavity by pressurizing the molten metal in a pop off pipe after the surface of the molten metal poured into the product part of dies solidifies. CONSTITUTION:The molten metal poured from a sprue pipe 12 of the dies 4 forming a caliber body, etc. is branched in the sprue and enters respective molding spaces 7. The molten metal rises into the pip off pipe 11 after filling the inside of the spaces 7. The molten metal in the pipe 1 is pressurized by a pressurizing piston 24 to pressurize the unsolidified part of the caliber body upon solidification of the surface of the caliber body. Cooling fins 16 and cooling pipes 17 deprive the thick walled part of part of heat so that the entire part of the caliber is uniformly solidified when each caliber solidifies The product having the intricate shape is produced by the above-mentioned method without generating shrinkage cavity.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a method for casting a casting, and particularly to a method for making a U-shape for a casting having a complicated shape.

[Conventional technology]

Usually, in casting molds, in order to prevent the formation of cavities when the injected molten metal solidifies and shrinks during the cooling process, a lagoon is provided in which the molten metal solidifies from the product section, and the lagoon is heated. Compatible.

[Problem that the invention seeks to solve]

However, when casting a product with a complicated shape, it may not be enough to prevent the formation of evacuation cavities by simply applying heat.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a casting method that prevents the occurrence of cavities even in products with rough shapes.

[Means for solving problems]

In order to achieve the above object, the present invention is characterized in that the surface of the wI lagoon injected into the product part of the mold is solidified, and the molten metal in the lifting part, which becomes the final solidification part, is pressurized.

[For production]

As a result, the pressure of the lifting portion acts on the unsolidified portion of the product, making the structure of the unsolidified portion highly dense and uniform, thereby preventing the formation of shrinkage cavities.

〔Example〕

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which the present invention is applied to the uNh method for molding disc brake calipers for motorcycles will be described below with reference to the drawings.

The caliper main body 1 shown in FIGS. 1 and 2 is a cast product molded by the casting method of this embodiment, and can be divided into two-bot type by combining with an integral cover 2 formed with another casting mold. A mold caliper 3 is constructed.

This caliper main body 1 includes cylinders 1a, 1a into which the actuating piston is inserted, a construction 17311c formed with an insertion hole 1b for a hanger bin that suspends the friction pad, and a connecting bin that connects the cover unit 2 which becomes the original operating part. A bridge portion 1e in which insertion holes 1d and 1d are formed.

The mounting section 1f and the mounting section 1f for mounting on the vehicle body further include a boss section 1 for introducing hydraulic fluid outside the operating section 1C.
q and a boss portion 1h for Bruda are integrally formed.

VI alloy mold 4 and fixed mold 5 for molding the caliper body 1
It is a split mold consisting of a movable mold 6 and a movable mold 6, and the joint surfaces 5a and 6a of both molds 5.6 have four parts 5b and 6b on the left and right sides for simultaneously molding two caliper bodies for the front and rear of a motorcycle. The recesses 5b, 6b can integrally accommodate the core forming the cylinder 1a, the insertion hole 1b, etc. of the caliper 1, and the caliper body 1.1 is formed by abutting both the recesses 5b, 6b. Two molding spaces 7, 7 are formed.

In the upper part of each molding space 7, a hole 8 is formed by the grooves 5c and 6c formed on the joint surfaces 5a and 5a by butting the two molds 5 and 6, and the hole 8 is formed in the upper part of the hole 8. A large diameter hole is formed by semicircular holes 5d and 6d opening on the upper surface of the mold.

Also, between both molding spaces 7°7, a horizontal semicircular hole 5e,
A runner 9 consisting of runners 6e and 6e is formed, and a sprue hole 10 formed by semicircular holes 5f and 6f is installed in the middle upper part of the runner 9, and a sprue hole 10 formed by semicircular holes 5f and 6f is installed. Damage tube 11゜1
1, and a sprue pipe 12 is fixed to the sprue hole 10, respectively.

The lifting pipe 11.11 and the sprue pipe 12 are connected to the sleeve half 13.
a, and mounting for fixing the half body 13a to the molds 5 and 6 [the half body 13 formed from the bracket 13b,
Since each mold 5, 6 is fixed to the upper surface of the mold 5, 6 with a bolt 14, by joining both molds 5, 6, a sleeve is formed with half bodies 13, 13 facing each other, and the damaged pipe 11 is lifted up. By attaching it to the upper surface of the large diameter hole above the hole 8, the sleeve of the lift pipe 11 and the lift hole 8 are connected, and the bracket 13b
, 13b cover the upper surface of the large diameter hole to form an air heat insulating layer 15.

Cooling fins 16 are provided on the curved surface and back surface of the fixed mold 5.
Two of the movable molds 6 are provided in a protruding manner, and a cooling pipe 17 is screwed into the movable mold 6.

These cooling fins 16 and cooling pipes 17 promote the cooling of the thick portion of the caliper body 1 during molding, and aim to make the solidification speed of other uniformly thick portions the same as that of the pawls, thereby making it possible to cool the entire caliper body 1. The cooling fin 16 consists of a piece 18 that is press-fitted into the fixed mold 5 and a plurality of pieces 19 that are screwed onto the piece 18. The cooling fins 16 are formed by adjusting the cooling efficiency to a desired level by combining the pieces 19 in multiple stages while increasing and decreasing the contact area.

The cooling pipe 17 has two through holes 17 bored in the pipe body 17a.
A cooling path is formed by connecting hoses 20.20 to the outer ends of b and 17b, respectively, and cooling is performed by flowing air or a mixed fluid of air and water into the cooling path. Further, a rotation lever 21 for rotating the cooling pipe 17 is fixed on the outer periphery of the hose connection side of the tube body 17a, and by rotating the lever 21, the inner end of the tube body 17a and the screw hole 22 By changing the gap 23 to the bottom, the cold IA efficiency can be adjusted.

The cold Uj fins 16 are installed on the upper surface and back surface of the boss portion 1g for introducing the working fluid, which is thicker than other uniformly thick portions and solidifies slowly in each part of the caliper body 1 to be cast, and on the cooling pipe 17. The cooling fins 16 are provided in close proximity to the front surface of the insertion hole 1b of the hanger bin in which the friction pad is attached, and cooling fins 16 are provided so that the thick wall portion solidifies in the same manner as other pressure equalizing portions.
and adjust the cooling pipe 17 to set the cooling efficiency.

In addition, 24 is a pressurizing piston.

Next, to explain the forming using the vI alloy forming mold 4 of this embodiment, the molten metal injected from the sprue pipe 12 branches left and right at the runner 9 and enters each forming space 7.7. 7, 7 are filled and lifted into lift pipe 11.11. After the surfaces of the caliper bodies 1.1 are solidified, the molten metal in the lift tube 11.11 is pressurized by the pressurizing piston 24, thereby pressurizing the unsolidified portion of the caliper body 1.1 to increase the structure. It evens out the density and prevents the formation of nests. Further, when each caliper 1 is solidified, the cooling fins 16 and the cooling pipes 17 remove part of the heat from the thick portion, and the entire caliper 1 is uniformly solidified.

〔Effect of the invention〕

As described above, in the present invention, after the surface of the molten metal injected into the product part of the mold solidifies, the molten metal in the lifting part which becomes the final solidification part is pressurized, so the structure of the unsolidified part of the product part is enhanced. By making the density uniform, it is possible to prevent the occurrence of cavities and improve manufacturing efficiency and quality.

[Brief explanation of drawings]

The figures show one embodiment of the present invention, in which Fig. 1 is a perspective view of the caliper main body, Fig. 2 is a cross-sectional view of the caliper main body and a cover formed in combination therewith, and Fig. 3 is a perspective view of the casting mold. FIG. 4 is a sectional view, and FIG. 5 is a front view of the fixed mold.

Claims (1)

[Claims] 1. A method for casting a casting, which is characterized in that after the surface of the molten metal injected into the product part of the mold has solidified, the molten metal is pressurized in a lifting part that becomes the final solidification part.