JPS6350059Y2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to a casting mold that is used with a core disposed in a cavity formed by a first mold and a second mold, and is particularly characterized by the positioning of the core. The present invention relates to a casting mold having:

Conventionally, positioning of the core in a casting mold using a core was done by sandwiching the baseboard of the core between the baseboard supports of the outer mold (main mold) consisting of the first and second molds. I was worried. Appropriate clearance is provided between these baseboards and the baseboard receiver to accommodate the core in the correct position, but for example, in the case of a horizontally split mold, the inner part that comes into contact with the molten metal during pouring is Thermal expansion is greater than that of the outer parts that are not in contact with it, so the upper and lower molds tend to warp outward.
A fairly large gap may occur between the baseboard and the baseboard support. In this case, the position of the core is not sufficiently defined, and the core may be pushed up or tilted by the buoyancy of the molten metal, resulting in considerable variation in the dimensions of the cast product. Become. In addition, in the case of sand molds, thermal deformation is not so much of a problem, but there is also the problem of tilting within the clearance between the baseboard and the baseboard support, and although it is not as bad as with molds, it affects the product dimensions. Variations occur.

This is true not only for horizontally split casting molds, but also for so-called vertically split molds, where the gap between the baseboard and the baseboard support causes uneven dimensions of the product. It is.

With the above-mentioned circumstances as a background, the present invention has been developed to create a casting mold that can position the core almost unaffected by the clearance between the baseboard and the baseboard holder, and that can produce cast products with little variation in dimensions. It was made with the purpose of providing.

The gist of the present invention is that, in a casting mold used with a core disposed in a cavity formed by a first mold and a second mold, one of the two molds is used. A movable member movable in a direction substantially perpendicular to the mating surfaces of both molds is provided in the portion of the core corresponding to the baseboard, and by pressing the movable member against the baseboard using a pressing means, the baseboard can be moved. The main feature is that it is fixed by being pressed against the baseboard holder of the other of the above two types. Note that the pressing means for pressing the movable member may be gravity acting on the movable member, or may be one that utilizes the elastic force of an elastic member.

By doing the above, the baseboard of the core is kept pressed by the movable member against the baseboard support of one of the two molds, and the core is accurately positioned with respect to that one mold. Fixed. Therefore, even if there is a clearance between the baseboard and the baseboard support,
During pouring, the core does not float up, drop, or tilt, and is maintained in a stable state.
This makes it possible to suppress variations in the dimensions of the resulting cast product.

Hereinafter, an embodiment in which the present invention is applied to a horizontally split casting mold will be described in detail based on the drawings.

A mold 2 shown in FIG. 1 is used to cast light alloy products such as aluminum alloy. This mold 2
are the upper mold 4 as the first mold and the lower mold 6 as the second mold.
It is opened and closed by a mold opening/closing device (not shown). When the molds 4 and 6 are brought together at the mating surface A, a cavity is formed that spans both molds, and a product cavity 10 is formed by disposing the core 8 in the cavity.

The core 8 is provided with baseboards 12 at both ends thereof, while the upper mold 4 and the lower mold 6 are each provided with a baseboard receiver 14 that accommodates each baseboard 12 in a sandwiched manner. The baseboard 12 is provided with a draft angle, and the shape of the baseboard receiver 14 is determined accordingly. A clearance Δl of, for example, about 0.2 mm is provided between the wood support 14 in the vertical direction.

The upper mold 4 is formed with stepped through holes 16 that penetrate the upper mold 4 in a direction perpendicular to the mating surface A of the two molds 4 and 6 and open to each baseboard receiver 14. A weight 18 as a movable member is fitted into the through holes 16 so as to be slidable in the vertical direction. The through hole 16 is sandwiched between the stepped surface 20 and has a large diameter hole on the upper side and a small diameter hole on the lower side.
consists of a head 22 that fits into the large-diameter hole and a leg 24 that fits into the small-diameter hole. The tips of the legs 24 are designed to be able to penetrate into the inside of the baseboard receiver 14, but when both molds 4 and 6 are opened, the shoulder surface of the head 22 and the stepped surface 20 do not come into contact with each other. As a result, entry limits are being regulated.

Skirting board support 14 of mold 2 configured as above
The skirting board 12 of the core 8 is housed in the baseboard 12 of the core 8, and both molds 4 and 6
When the shapes are aligned, the head 22 is raised a certain amount from the stepped surface 20, and the weight 18 rests on the upper surface of the baseboard 12 with its leg 24,
The baseboard 12 is pressed against the baseboard receiver 14 of the lower die 6 by its own weight. That is, in this embodiment, gravity serves as a pressing means for pressing the weight 18 against the baseboard 12. The weight of this weight 18 is set to be large enough to overcome the buoyant force that the core 8 receives when pouring molten metal, and is generally made of metal.

When molten metal is poured into the product cavity 10 with the core 8 positioned and fixed in this manner, the inner parts of both molds 4 and 6 forming the cavity 10 are in direct contact with the molten metal, so the outer parts that are not in contact with the molten metal are Thermal expansion is larger than that of the parts, and both molds 4 and 6 are thermally deformed so as to warp outward as shown by the imaginary lines, and the effect is particularly greatest in the parts of the baseboard supports 14 on both sides. As a result, the baseboard 12 and the baseboard support 14
For example, the clearance Δl in the vertical direction with
However, since each baseboard 12 is pressed against the baseboard receiver 14 of the lower mold 6 by each weight 18, regardless of the increase in the clearance Δl, The core 8 is prevented from being pushed up or tilted by the buoyancy of the molten metal, and is kept stably positioned and fixed relative to the lower mold 6. Therefore, it is necessary to cast products with uniform dimensions, especially the core 8 and the lower mold 6.
This makes it possible to perform casting in which the thickness of the part formed between the molds 4 and 6 is hardly affected by thermal deformation of the molds 4 and 6.

Note that as the molds 4 and 6 are thermally deformed, the core 8 is slightly biased downward with respect to the center line of the cavity 10.
It is desirable that the core 8 be slightly shifted toward the side of the cavity 10 so that the core 8 can be finally located at the center of the cavity 10.

In the above embodiment, the upper mold 4 and the lower mold 6 are used as molds, but even if they are sand molds, pressing the baseboard 12 by the weight 18 is effective. In the case of a sand mold, the thermal deformation during pouring is not so large, but even in a state where there is no thermal deformation, it is impossible to completely eliminate the clearance between the baseboard 12 and the baseboard receiver 14, and there is some In addition, since the casting material often has a high specific gravity such as cast iron, the buoyancy force applied to the core 8 also increases. It is still effective to accurately position the child 8.

Incidentally, in the embodiment described above, the baseboard 12 was pressed against the lower mold 6 by the weight of the weight 18, but it is also possible to construct the baseboard 12 as shown in FIG. 2 instead. That is, the slider 26 is fitted into the through hole 16 of the upper mold 4 so as to be slidable in the vertical direction, and the coil spring 30 is compressed and preloaded between the slider 26 and the plate 28 that closes the upper opening of the through hole 16. The movable body 26 is pressed against the baseboard 12 by the spring 30, and the baseboard 12 is pressed against the baseboard receiver 14 of the lower mold 6. In this case, slider 2
6 also serves as a weight, but spring 3
It also plays the role of transmitting zero elastic force to the baseboard 12, and the spring elastic force and gravity serve as a pressing means.

By doing this, the slider 26 can also be used when opening and closing the mold.
There is less wobbling, and the weight of the slider can be reduced by the elastic force of the spring.

Further, as shown in FIG. 3, a bottomed hole 32 that opens to the baseboard receiver 14 is formed in the upper mold 4, a ring-shaped spring 34 is attached to the bottom of the hole 32, and the flat part of this spring 34 is connected to the baseboard 14. It is also possible to position the core 8 by pressing against it. In this case the spring 34
The flat part of the plate will serve as a movable member.

Furthermore, in the above embodiment, it was planned to use both horizontal baseboards, but as shown in FIG.
Even in case 2, if the casting material is light in specific gravity, such as magnesium alloy, positioning using the weight 18 or the like can also function effectively. The same applies to the passing baseboard 38 as shown in FIG. 5, and in that case, it is desirable that the weight 18, slider 26, etc. be shaped into blocks corresponding to the length of the baseboard 38.

Furthermore, regarding the skirting board, as shown in FIG. It is also possible to press the end surface of the lower baseboard 42 against the baseboard receiver 44 of the lower mold 6, so that the vertical play of the core 8 will affect the product dimensions, as shown in the figure. It is effective in such cases.

Additionally, if we consider that the casting mold shown in Figures 2 or 3 is not a horizontally split one, but a so-called vertically split one, the present invention can be applied even in the case of such a vertically split casting mold. It is understood that the benefits can be enjoyed by In that case, since the element of gravity is not applied to the slider 26 etc., the spring 30
Alternatively, the pressing action is exerted by the elastic force of the spring 34.

In addition, it goes without saying that the present invention can be implemented in various modifications, improvements, combinations, etc. based on the knowledge of those skilled in the art without departing from the scope of the claims for utility model registration.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing a state in which a core is disposed in a horizontally split casting mold which is an embodiment of the present invention. FIGS. 2 and 3 are partial cross-sectional views showing other embodiments of the present invention, respectively. FIGS. 4 and 6 are sectional views showing further embodiments of the present invention, respectively. FIG. 5 is a perspective view showing an example of a baseboard configuration to which the present invention can be applied. 2... Mold (casting mold), 4... Upper die (first die), 6... Lower die (second die), 8... Core, 10...
...Product cavity, 12, 38, 40, 42...
Skirting board, 14, 44... Baseboard support, 16... Through hole, 18... Weight (movable member), 26... Slider (movable member), 30... Coil spring (pressing means), 34... Spring (pushing means and movable member),
A...Mating surface.

Claims (1)

[Scope of utility model registration request] In a casting mold used with a core disposed in a cavity formed by a first mold and a second mold, a portion of the core of one of the two molds corresponding to the baseboard is By providing a movable member movable in a direction substantially perpendicular to the mating surfaces of both molds, and pressing the movable member against the baseboard by a pressing means,
A casting mold characterized in that the baseboard is fixed by being pressed against the baseboard holder of the other of the two molds.