GB2148762A - Apparatus for separating the sprue section from casting in sand mold - Google Patents

Abstract

Sand 5 in a moulding flask 1 is pressed by a device comprising a plate 11B and a piston 11 to fix the position of the casting in the sand mould. The runners are cut by means of a device reciprocated by piston 12 to separate comprising cutters 16 fixed to a plate 15 the cast product section of the casting from the sprue section in the sand mould. In a second embodiment the cutters can be replaced by a clamping device which clamps onto the sprue and is then moved upwards by a piston thus separating the sprue section. <IMAGE>

Description

SPECIFICATION Apparatus for separating the sprue section from casting in sand mold This invention relates to an apparatus for separating the sprue section from a casting. More particularly, the invention is concerned with an apparatus for separating the sprue section from the cast product section of a casting in sand mold.

Background of the Invention When a casting is produced in a sand mold, the sand mold is generally provided with a sprue and communicating runners and the molten metal is poured into the sprue. Accordingly, the formed casting comprises a sand mold section (cast product section of the casting), a runner section and a sprue section (sprue section of the casting), all as integral part. In the prior art, the casting is removed by dismantling the molding flask and disintegrating the sand mold. Then, the sprue section is separated from the casting by hammering, press cutting, gas cutting, or grinder cutting.

However, when the hammering is performed, the operation is quite troublesome for workers as the casting is at a high temperature. Even if the hammering is conducted after cooling of the casting for mitigating the burden of the operation, such an operation requires a pertinent area for cooling.

Thus, the operation involves the wastage of time and space.

On the other hand, a casting as removed from molding sand in molding flask has adhering particles of sand on the surface. In the case of press cutting, flying particles of sand from said casting wear a cutting edge as cavity or force of a press and induce troubles in machine. To avoid these difficulties, a step of cleaning the casting is required as pretreatment. Thus, the bulky casting wherein the cast product section is connected to the sprue section must be cleaned. Consequently, a superfluous plant investment is necessary for transferring installation and cleaning apparatus.

In the case of grinder cutting, the grinder wheel is destroyed if the temperature of the casting is high.

Thus, cooling is required.

When the separation is performed by gas cutting, a casting at an elevated temperature can be handled. However, the operating conditions are quite deteriorated forworkers. Furthermore, the operation is highly dangerous as a combustible gas is employed.

Summary of the Invention These problems of the prior art are intended to be solved by the present invention which comprises providing an apparatus for separating the sprue section of a casting in sand mold consisting of a device for pressing molding sand and a device for splitting runner above a sand mold, pressing the molding sand by said device for pressing molding sand to fix the position of the casting in sand mold, and pulling the sprue or cutting the runners under such pressed condition by means of said device for splitting runner to separate the sprue section from the cast product section of the casting in sand mold.

Brief Description of the Drawings Some of the objects of this invention having been stated, other objects will appear as the description proceeds when taken in conjunction with the accompanying drawings, in which: Fig. 1 is a perspective view of an embodiment of this invention, Fig. 2 illustrates the use of the apparatus shown in Fig. 1, Fig. 3 is a perspective view of another embodiment of this invention, and Fig. 4 illustrates the use of the apparatus shown in Fig. 3.

In these figures, the same reference numeral or letter depicts the same part which has the same appellation and the same function.

Description ofthe Preferred Embodiments Now, one embodiment of this invention which is shown in Figs. 1 and 2 will be detailed. In Figs. 1 and 2, a molding flask 1 which has been set on a molding board 2 comprises a cope secton 3 and a drag section 4. In molding flask is the molding sand 5 in which are shaped a sand mold 6, runners 7 and 18, a sprue 8 and a riser 17, these spaces communicating with one another. A molten metal is poured into the sprue to shape a casting comprising a cast product section 13 and a sprue section consisting of runners 7 and 18, a sprue 8 and a riser 17.

The molding flask 1 is supported by a vibrating conveyor 9 via the molding board 2. A frame 10 constructed of steel stock is arranged above the molding flask 1. On this frame 10 is mounted an apparatus C for separating sprue section comprising a device A for pressing molding sand and a device B for splitting runner.

The device A for pressing molding sand consists of a pressing cylinder 11 mounted on said frame 10, a piston 11 a thereof, and a pressure plate 11 b. The presser plate 11 b which is fixed to said piston 11 a of pressing cylinder 11 has holes 11 1cfor allowing cutter to pass. These holes 11 care formed so as to be located at cutting places of runner 7 of sprue 8 and of runner 18 of riser 17.

The device B for splitting runner, is composed of a cylinder 12 for push cutting which arranged on said frame 10, a piston 12a thereof, a cutter-mounting plate 15 fixed to said piston 12a, and cutters 16 mounted on said cutter-mounting plate 15. In this cutter-mounting plate 15 is formed a hole 12for piston of pressing cylinder 11. In addition, plural cutters 16 and arranged in the lower surface of said mounting plate 15.

A cutter 16 has a length different from those of other cutters. For example, a cutter 1 6a is formed to have a length of Ii and a cutter 16b is formed to have a length of 12, the former being shorter than the latter. The number of cutters 16 corresponds to that of places to be cut in the casting.

Now, the operation of this embodiment will be explained. The piston 1 la of the pressing cylinder 11 is moved downward in the direction of arrow All so that the presSer plate 11 b presses the molding sand 5 on the cast product section 13 of the casting to fix the position of the casting. Then, the piston 12a of cylinder 12 for push cutting is moved downward at one stroke in the direction of arrow A12. Cutters 16 arranged on the mounting plate 15 rapidly pass through the holes llcforpassing cutter and cut runners 7, 18, etc. To this end, cutters 16 the number of which is corresponding to that of runners 7, 18, etc. have different lengths, such as 11 and 12 depending on the depth of respective runner in sand.However, the point of time of cutting respective runner is slightly differentiated one another by adjusting the length of respective cutter.

As a result, the power of cutting is effectively economized. During one stroke, the cast product section is completely separated at every cutting point. Thus, it is possible that not only the sprue but also the riser, the gate and the like are simultaneously cut off by plural cutters and all runners are split in the sand mold.

The present invention is not limited to the abovementioned embodiment. As an example, the device A for pressing molding sand and the device B for splitting runner can be composed as described in the following with referring to Figs. 3 and 4 of the accompanying drawings.

In Figs. 3 and 4, the device A for pressing molding sand consists of a pressing cylinder 11 arranged on the frame 10, a piston 21 thereof, and a presser plate 22. Said presser plate 22 which is mounted on piston 21 of said pressing cylinder 11 has a size sufficient to cover almost the entire interior of molding flask 1. The presser plate is shaped to have a cutout 23 for clamping claws.

In the device B for splitting runner, clamping claws 25 are movably attached to an end of a piston 24 which is engaged with a cylinder 12. A clamp cylinder 26 is provided between clamping claws 25.

Now, the operation of this second embodiment will be explained. The piston 21 of the pressing cylinder is moved downward in the direction of arrow A21 so that the presser plate 22 presses the molding sand 5 on the cast product section 13 of the casting to fix the position of the casting. Then, the piston 24 of cylinder 12 is moved downward in the direction of arrow A24. The clamping claws 25 pass through the cutout 23 to penetrate into the molding sand 5. Then, the clamp cylinder 26 is actuated to clamp the sprue 8.

However, the clamping claws 25, at this point of time, cannot directly grip the sprue 8 because the hard molding sand 5a surrounding the sprue 8 inhibits the direct contact between the sprue and the clamping claws. Thus, the clamped state is not complete.

Then, with maintaining the actuated state of clamp cylinder 26 the piston 24 of the cylinder 26 for pulling is reciprocated vertically (in the direction of arrow A24) within a distance of 550 mm. The motion is repeated several times without interruption. By virtue of these motions, the hard molding sand 5 surrounding the sprue 8 is disintegrated and scraped down by clamping claws 25, and the sprue can be directly gripped by clamping claws.

As the clamped state is now complete, the clamped state can sufficiently withstand the reaction from separating the sprue. Thus, a clamp error which may be generated at the time of separating the sprue can be eliminated.

After the clamping is completed in this way, the piston 24 of cylinder 12 is moved upward to separate the sprue section from the cast product section 13. Thereafter, the molding board 2 is removed and the vibrating conveyor is acruated for separating the cast product section of the casting from molding sand.

At this invention is constituted as mentioned above, the division of the casting into the cast product section and the sprue section can be achieved within the sand mold.

The separating operation according to this invention can be performed safeiy and hygienically because the operation is scarcely accompanied by flying of splinters from castings and molding sand in the course of separating the sprue section and the like from castings. Furthermore, the use of an apparatus in accordance with this invention makes a casting operation more economic and efficient as there are no problems concerning space for cooling and cooling time in contrast to the use of a prior apparatuses.

Claims (8)

1.An apparatus for separating the sprue section from a casting in sand mold which is characterized by comprising a device for pressing molding sand and a device for splitting runner, said devices having been arranged above said sand mold.

2. An apparatus for separating the sprue section from a casting in sand mold, as set forth in claim 1, in which said device for pressing molding sand comprises a pressing cylinder and a presser plate attached to a piston engaged with said pressing cylinder.

3. An apparatus for separating the sprue section from a casting in sand mold, as set forth in claim 2, in which said presser plate is shaped to have holes for passing cutter.

4. An apparatus for separating the sprue section from a casting in sand mold, as set forth in claim 1, in which said device for splitting runner comprises a cylinder for push cutting, a cutter-mounting plate fixed to a piston of said cylinder, and cutters mounted on said cutter-mounting plate.

5. An apparatus for separating the sprue section from a casting in said mold, as set forth in claim 4, in which a plurality of cutters are mounted and their lengths are differentiated one another.

6. An apparatus for separating the sprue section from a casting in sand mold, as set forth in claim 2, in which said presser plate is shaped to have a cutout for clamping claws.

7. An apparatus for separating the sprue section from a casting in sand mold, as set forth in claim 1, in which said device for splitting runner comprises clamping claws attached to a piston of a cylinder and a clamp cylinder arranged inside said clamping claws.

8. Apparatus substantially as hereinbefore described with reference to, and as shown in, the accompanying drawings.