JPS643565Y2 - - Google Patents

Description

[Detailed description of the invention] (Field of industrial application) This invention is a sand mold shift prevention method for connecting and restraining a pair of green sand molds, which are used in combination to form a mold, so that they do not displace each other during casting. Regarding jigs.

(Prior art) Conventionally, green sand molds have been widely used for casting various products, but due to the shape of the casting pattern during the production of these green sand molds, the filling density of the green sand tends to vary, making it difficult to cast. There is a drawback that the molten metal pressure sometimes causes the mold sand to move toward the lower density side, reducing the dimensional accuracy of the product.

In particular, when casting a pair of upper and lower green sand molds, the shapes of the upper and lower molds are different, and the filling density of the green sand is not uniform, so the molten metal pressure during casting causes the upper and lower molds to There was a problem in that the dimensional accuracy of the cast product was significantly reduced due to relative displacement between the two.

(Purpose of the invention) In order to solve the above-mentioned problems, the present invention provides a sand mold slippage prevention jig with a simple structure that connects and restrains a pair of green sand molds and suppresses relative slippage between them. The purpose is to provide.

(Structure of the invention) The sand mold slippage prevention jig of the invention is provided with a connecting plate that is inserted from each mating surface of a pair of green sand molds to the ambidextrous sand mold, and is connected from the approximately middle part of the connecting plate. An insertion amount regulating plate is provided that protrudes outward from at least one side of the plate and is held between the mating surfaces of the ambidextrous sand mold.

(Effects of the invention) Since the invention is constructed as described above, the molds are connected by a connecting plate that is inserted into both molds from the mating surfaces of the pair of green sand molds, so that the mold sand can be removed during casting. Even if the packing density is uneven, the upper and lower molds will not shift relative to each other, improving the quality and dimensional accuracy of the cast product, reducing the incidence of defective products, and simplifying the structure and making it cheaper to implement. Since it does not wear out, it can be used repeatedly.

(Example) Embodiments of the present invention will be described below with reference to the drawings.

As shown in FIGS. 1 and 2, the green sand molding device M positions a lower mold 2 and an upper mold 3 in order on a cart 1 or a surface plate using stacking pins 4, and a weight 5 is placed on the upper mold 3. It is constructed by placing.

Each of the upper mold 3 and lower mold 2 is manufactured by placing a pattern in a mold 6 and filling it with mold sand 7 using a molding machine or by manual molding, and the present invention prevents the sand mold from shifting. The jig J is set by piercing one of the mating surfaces 8 (for example, the mating surface 8 of the lower mold 2) where the upper mold 3 and the lower mold 2 come into close contact with each other before combining them after manufacturing the upper mold 3 and the lower mold 2, In that state, upper mold 3
By overlapping the upper mold 3 and the lower mold 2, the sand mold misalignment prevention jig J is stabbed into the upper mold 3 and the lower mold 2, thereby connecting the two and removing the upper mold 3 during casting.
This restricts the relative displacement movement of the lower mold 2 and the lower mold 2 in the horizontal direction.

Fig. 3 is a bottom view of the upper mold 3 viewed from the mating surface 8 side;
FIG. 4 is a plan view facing the mating surface 8 of the lower mold 2,
When both are combined, a molding cavity 9 is formed by the combined molding recess 9a of the upper mold 3 and the molding protrusion 9b of the lower mold 3,
The molten metal flows from the sprue 10 of the upper mold 3 through the runner 11 into the molding cavity 9.

As shown in FIG. 4, the sand mold misalignment prevention jig J is arranged along the periphery of the molding cavity 9 in a polygonal line shape in plan view, excluding the part of the mating surface 8 of the lower mold 2 that faces the runner 11. Then, the upper mold 3 is superimposed on the lower mold 2.

This sand mold slippage prevention jig J is an example of the fifth
As shown in the figure, it is formed by pressing a strip-shaped thin metal plate with a thickness of about 1 to 2 mm, and the insertion amount is controlled by bending it from the approximately middle part of the vertical connecting plate 12 and protruding horizontally. Each connecting plate 12 consists of a trapezoidal upper half 12a and an inverted trapezoidal lower half 12b partially continuous below the trapezoidal upper half 12a. The insertion amount regulating plate 13 extending laterally from the lower part of 12a is the connecting plate 1.
An insertion amount regulating plate 13 that protrudes outward from one side of 2 and extends laterally from the upper part of the lower half 12b is connected to the connecting plate 12.
The insertion amount regulating plate 13 that protrudes to the outside of the other side, and the insertion amount regulating plate 13 that protrudes to the outside of the one side and the insertion amount regulating plate 13 that protrudes to the outside of the other side form a single horizontal member that connects adjacent connecting plates 12. ing.

The sand mold misalignment prevention jig J is constructed by bending the connecting plate 12 at an appropriate angle at an appropriate point so as to follow the shape of the outer part of the outer periphery of the molding cavity 9 as much as possible. Although it is formed in a polygonal line shape consisting of sides, it is of course possible to form it in a circular arc shape when viewed from above. It may be placed as appropriate.

And the connecting plate 1 of the sand mold shift prevention jig J
The lower half part 12b of 2 is first inserted perpendicularly into the mating surface of the lower mold 2, and the insertion amount regulating plate 13 is brought into contact with the mating surface 8. In this state, the upper mold 3 is stacked on the lower mold 2, and the upper mold 3
When the upper half 12a of the connecting plate 12 is inserted vertically into the mating surface 8 of , the insertion amount regulating plate 13 is held between the mating surfaces 8.

In order to make it easier to insert the connecting plate 12 into the mold sand, the middle part of the connecting plate 12 has a thickness of about 2 mm.
Although it is desirable to form the layer so that it becomes gradually thinner toward the upper and lower ends, it may have a uniform thickness over the entire surface.

Further, the shapes of the connecting plate 12 and the insertion amount regulating plate 13 are not limited to those described above, and various shapes can be considered.

For example, as shown in FIG. 7, the shape of the connecting plate 12 may be simplified, or as shown in FIG. Multiple insertion amount regulating plates 1
3 may protrude outward from one side, and as shown in FIG. 9, the insertion amount regulating plates 13 may be fixed to both sides of the middle part of the rhombic connecting plate 12 by means such as welding.
Or the connecting plate 12 and a bending member consisting of the upper half 12a of the connecting plate 12 and one insertion amount regulating plate 13.
A bending member consisting of the lower half part 12b and the other insertion amount regulating plate 13 may be welded at the ridge line, or as shown in FIG. It can be bent at right angles. However, a large number of the devices shown in FIGS. 9 and 10 need to be arranged on the outside of the outer periphery of the molding cavity 9.

In short, sand mold shift prevention jig J according to the present invention
The connecting plate 12 may include a connecting plate 12 and an insertion amount regulating plate 13 that projects laterally from a substantially middle portion of the connecting plate 12 to the outside of at least one side of the connecting plate 12.

The sand mold shift prevention jig J functions as follows.

A connecting plate 12 which is arranged to face the molding cavity 9 on the outer side of the outer periphery of the molding cavity 9 consisting of the upper mold 3 and the lower mold 2 and which is inserted into the upper mold 3 and the lower mold 2 is During casting, the upper mold 3 or the lower mold 2 is moved by the pressure of the molten metal toward the side with a lower filling density of mold sand, and functions to connect the two and restrain each other so that the two do not displace relative to each other.

In addition, the insertion amount regulating plate 13 is also used when inserting the connecting plate 12 of the sand mold slippage prevention jig J into the lower mold 2.
It also functions as a stopper when inserting the connecting plate 12 into the upper mold 3 with the upper mold 3 stacked on top of it, and when the lower mold 2 and upper mold 3 are stacked on top of each other, the insertion amount regulating plate 13
is held between both mating surfaces 8 and fitted into the mold sand side, so that both mating surfaces 8 of the lower mold 2 and the upper mold 3 are in contact with each other without any gap.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention; FIG. 1 is an exploded vertical side view of the green sand molding device, FIG. 2 is a vertical side view of the green sand molding device, FIG. 3 is a bottom view of the upper mold, and FIG. Figure 4 is a plan view of the lower mold, Figure 5 is a perspective view of the sand mold displacement prevention jig, Figure 6 is an enlarged view of Figure 2, and Figures 7 to 10 are each of the sand mold displacement prevention jig. It is a perspective view of each modification. 2...Upper mold, 3...Lower mold, 8...Mating surface, 12
... Connection plate, 12a ... Upper half, 12b ... Lower half, 13 ... Insertion amount regulating plate.

Claims (1)

[Scope of utility model registration request] A connecting plate that is inserted from each mating surface of the pair of green sand molds across the two green sand molds, and a connecting plate that protrudes outward from at least one side of the connecting plate from approximately the middle part of the connecting plate and is sandwiched between the mating surfaces of the green sand molds. A jig for preventing sand mold displacement, characterized by comprising an insertion amount regulating plate.