JPS6322901B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a split mold for integrally bonded cores, particularly a cold box integrally bonded core mold having a mechanism for dividing and closing the mold in front, back, left, right, and diagonal directions within a sealed box. Regarding split molds for

In the present invention, an "integrated joint core" refers to a core with a complex shape or structure that is partially molded separately, and this molded core (joint core) part placed in a mold in advance. It refers to a completed core filled with molding material and joined together.

It is well known that mold making, especially cold box molding, is a method in which the molding material is cured by aeration of catalyst (or reaction) gas, and therefore it is necessary to seal the mating surfaces of the molds. Conventionally, in the case of a mold that takes many cores, the mold is divided into individual cores, and the divided molds are not individually provided with sealing means, but these divided molds are placed in a closed box with a seal. A method of configuring a composite mold housed within a mold is known. It is also known to partially combine a small-sized loose piece of a mandrel with a power source such as a cylinder as part of a mold for molding the core.

However, in the case of a core with an extremely complicated shape and structure as shown in Fig. 1, such as a core for a V-type six-cylinder engine, three Y-shaped cores each containing two upper cylindrical portions are required. These cores are separately molded, and the individual cores are glued together with adhesive and combined to form an integrated core.

The present invention provides a split mold for molding a cold box integrally bonded core, which is capable of molding such a complex core in a single molding operation.The technical configuration of the present invention is as follows. As specified in each claim, the present invention will be further described in detail based on the attached drawing showing a specific example of a split mold when the present invention is applied to molding a core as shown in FIG. .

Figure 2 is a partial sectional view taken along the line of Figure 3.
FIG. 3 is a plan view along the line of FIG. 2, and FIG. 4 is a perspective view showing the assembled state.

As shown in the figure, the lower mold of the split mold of the present invention has the following structure: A fixed mold 5 is provided on the lower mold die base 10. A pair of vise molds 2a are provided on both sides of this fixed mold 5,
These vice molds 2a and 2b are supported by pistons of vice mold drive cylinders 7a and 7b provided in the mold frame 9, and are moved forward and backward toward the fixed mold 5. In addition, vice type 2
A welding core positioning protrusion 14 is provided on the inner surfaces of a and 2b.
a and 14b are provided.

3a and 3b are a pair of loose pieces, which are configured to slide inside the vice molds 2a and 2b and perpendicular to the sliding direction of the vice molds by the operation of loose piece drive cylinders 8a and 8b. .

Reference numeral 4 denotes a mandrel, which penetrates the lower mold base 10 by operating a mandrel driving cylinder 6 provided on the lower mold base 10 and drives the fixed mold 5.
It is a mechanism that slides along the outer slope of the
Note that 11 is a lower mold mounting frame.

Reference numeral 1 denotes an upper mold having a fixed mandrel 1a on its lower surface, and a large number of molding sand blowing holes 16.
is provided.

Cold box molding of the above-mentioned upper and lower molds,
That is, when the molding material is cured by passing catalyst gas (or reaction gas), these divided molds are housed in a closed box, and the mechanism is such that the molds are opened and closed within the closed box. The closed box has been omitted.

The split mold of the present invention has the above-described construction, and the manner of the molding operation when it is set in a molding machine will be explained step by step.

The applicant separately proposed (patent application 1982-
No.) Pre-shaped cores 12 to be welded transported by a welding core feeding device described in "Fully automatic cold box integrated joining core making machine"
a and 12b are placed on the top of the fixed mold 5 and fixed. A positioning protrusion 15 is provided on the top of the fixed mold 5. Next, the vise molds 2a and 2b are closed by actuation of the cylinders 7a and 7b, forming the external side surface of the completed integrally joined core. As shown in FIG. 5, the cores 12a and 12b to be joined have a structure in which two pieces are pasted together, and the positioning protrusions 14a and 14b that fit into the gap between the two pieces are the vice molds 2a and 2.
A core 12a provided on the inner surface of b and to be joined,
12b more accurately.

Incidentally, after the joining core is set in the mold,
Since the molding material to be integrally joined with these cores is blown into the core, it is preferable to have an external shape that does not impede the fluidity of the molding material. FIG. 5 shows a cross section of the integrally bonded core, and it is understood that at least a part of the outer surface of the bonded cores 12a and 12b, that is, the outer surface through which the blown molding material passes, has a rounded shape S. It is preferable in terms of bonding and molding.

Then, the loose pieces 3a, 3b are closed by the actuation of the cylinders 8a, 8b, forming the side end surfaces of the completed integrally joined core. Mandrel 4 is cylinder 6
The mandrel 4 is raised to a predetermined position, that is, into the cylinder bore of the engine block in the illustrated example.

The lower mold assembled as described above is raised by a lifting device (not shown) and pressed into contact with the upper mold 1. At this time, a fixed mandrel 1a provided on the lower surface of the upper mold 1
The protrusion 17 provided on the side surface of the welding core 12a,
12b is prevented from moving during sand blowing and the mating surfaces are prevented from shifting.

The above operations complete the assembly of the split molds and completely configure the desired modeling cavity.

Next, molding sand is injected and filled through the molding sand injection hole 16 using a conventional method, and a catalyst gas is aerated, and the joining core and the molding sand blown surrounding it are joined together to form a completed core. do. The integrally bonded core that has been completely cured is operated in the reverse manner to the above-mentioned split mold assembly process, extruded and released by the extrusion mechanism of the molded core, and transported out by an unloader or the like.

The split mold of the present invention has the technical configuration and operation as described above, and therefore, according to the present invention, the following effects can be achieved: (1) Seal in a closed box The dimensional accuracy of the core is excellent because there is no need to seal each split die.

(2) Excellent dimensional accuracy of the core due to accurate positioning of the joining core.

(3) If the use of a bonding core results in poor sand flow and filling into the mold cavity, the shape of the integral joint of the bonding core may be arbitrarily changed to improve sand flow. It can be designed.

(4) Compared to other molding methods, such as heating molding,
The dimensional accuracy of the core is good, the hardening of the core is homogeneous and complete, and the integral adhesion and adhesiveness with the bonded core are excellent.

(5) Although the completed core has a complex shape, the mold dimensions have been made more compact, making it easier to design the molding machine.

(6) In addition to the fact that completed cores with complex shapes can now be molded in a unified state, the above (1) to (3)
Due to the synergistic effect of the advantages of the mold scheme and the welded core scheme described above, the core can be made compact and the casting can be made smaller and lighter. This leads to a smaller and lighter engine, which greatly contributes to resource conservation.

[Brief explanation of the drawing]

Figure 1 shows a V-type 6 manufactured using the split mold of the present invention.
A perspective view of a core for a cylinder engine, FIG. 2 is a partial sectional view taken along the line - in FIG. 3, FIG. 3 is a plan view taken along the line - in FIG. 2, and FIG. 4 is a perspective view showing an assembled state. FIG. 5 is a cross-sectional view of the integrally joined core, in which 1 is the upper mold, 2a, 2b are vice molds, 3a,
3b is a loose piece, 4 is a mandrel, 5 is a fixed type, 6 is a cylinder for driving the mandrel, 7a, 7
b is a vise-type driving cylinder, 8a and 8b are loose pieces, and 12a and 12b are cores to be joined.

Claims (1)

[Claims] 1. A fixed mold provided on the lower mold base, a pair of vice molds that slide and engage with each other, and a pair of loose pieces that slide perpendicular to the sliding direction of the vice molds. and at least one mandrel that penetrates and slides through the lower mold base, and a lower mold having a core insertion cavity to be joined, and a fixed mandrel on the lower surface and a large number of molding sand blowing holes. A split mold for an integrally bonded molding core, characterized in that it is combined with an upper mold having an upper mold. 2 having a positioning protrusion on the inner surface of the vise mold that fits into the gap between the two laminated cores to be joined;
A split mold for an integrally joined molding core according to claim 1. 3. The split mold for an integrally joined molding core according to claim 1, wherein a positioning projection is provided on the top of the fixed mold. 4. The split mold for an integral joint molding core according to claim 1, which is used for cold box molding, and has a mechanism in which the upper and lower mold assemblies open and close within a closed box. 5. The split mold for an integrally joined molding core according to claim 1, wherein at least a part of the outer surface of the core to be joined is shaped so as not to inhibit the fluidity of the molding material.