JPS6240099B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a casting method using ordinary steel, special steel, cast steel, etc.

Figures 1 to 4 show conventional casting methods, and in each case, the weight of the product is 1000.
This shows the case of casting large objects exceeding kg.

FIGS. 1 and 2 show the state of casting a bent pipe, in which a mold 1 made of foundry sand is made horizontally. This mold 1 has a core 2 made of the same material, and a runner 4 having a spout 3 at the upper end is vertically formed, and at the lower end, it branches at right angles to the left and right to form a branch runner 5. It further branches into a tip runner 6 and leads to a casting cavity 7, and in the upper part of this cavity 7 there are a plurality of feeder holes 8.
is provided.

In such a mold 1, when the required amount of molten metal is injected from the spout 3, the molten metal flows down the runner 4, bends at a right angle at the lower end, enters the branch runner 5, and further splits upward from the tip runner 6. The molten metal flows into the cavity 7, fills the cavity 7, and casts the bent pipe 9, and the excess molten metal flows into the feeder hole 8 and solidifies to form the riser part 10. Further, there is a recess for collecting a test piece at an appropriate location in the mold 1, and the molten metal flows into this recess to form a test piece 11.

Figures 3 and 4 show the case of casting a branch pipe by the conventional method, 12 is a mold, 13 is a core, 14 is two spouts, and the runners 15 following each spout are vertical. The lower ends thereof are divided at right angles to form two branch runners 16, and the tips of each branch runner 16 meet at a confluence point 17, and then split again to form a tip runner 18, whose tips are vertical. It extends to the lower part of the casting cavity 19.

In addition, a runner 20 is created by further branching the middle of one branch runner 16 in FIG.
A plurality of feeder holes 22 are provided at appropriate locations on 9 and 21.

In the above case as well, the molten metal injected from the two spouts 14 flows down each runner 15 and bends at right angles to the runner 1.
6, 18, and 20 to flow into the cavities 19 and 21 to cast the branch pipe 23, and the excess molten metal flows into the feeder hole 22 and solidifies, becoming the feeder portion 24 and entering the recess for collecting the test piece. Then, a test piece 24' is formed.

In each of the above conventional examples, the runner is initially vertical, bends at right angles, becomes horizontal, and finally turns upward to flow into the casting cavity to form products such as bent pipes and branch pipes. The air (gas) that accompanies the flow of the molten metal also flows in the same way, creating resistance to the flow of the molten metal and making it less smooth, as well as making it difficult for the air to escape, making it easy for cavities to form. In order to achieve this, it is necessary to perform casting while maintaining the temperature of the mold and molten metal within an optimal range, which is extremely troublesome because the optimal temperature varies depending on the shape and size of the casting and the material of the molten metal.

The purpose of this invention is to solve the above-mentioned drawbacks of the conventional casting method. A cavity is formed, and the runner provided in this mold is also provided at a steep angle from the spout at the upper end of the mold and curved into a smooth arc, and this runner is branched into a plurality of parts to form a runner at the lower end of the casting cavity. A mold with a feeder hole that opens into the upper part of the mold is installed at a suitable place at the upper end of the casting cavity, and a deep funnel-shaped spout that slopes along with the runner is installed at the upper end of the runner. Inject the molten metal along the low side of the funnel-shaped spout so that the molten metal flows along the low side of the runner and the gas flows from the high side of the runner to the high side of the spout. By casting the molten metal so that it escapes into the atmosphere along the mold, the surface of the molten metal becomes oblique to the mold in the cavity, so that air and gas can be vented smoothly.

The details of this invention will be explained below based on FIGS. 5 to 8.

In the case of the mold 25 for a curved pipe shown in FIGS. 5 and 6, the casting cavity 27 composed of the mold 25 and the core 26 is inclined at a steep angle with respect to the horizontal plane. This angle of inclination θ is determined appropriately depending on the size and shape of the product, the material and temperature conditions of the molten metal, but it is approximately 80° with respect to the horizontal plane.
A range of 60° to 60° is appropriate. In this embodiment, as is clear from the drawing, it is inclined at about 60 degrees with respect to the horizontal plane.

28 is a spout, but this spout 28 is also a blank space 27
It is sloped at approximately the same angle as , and has a deep funnel shape so that the molten metal can easily flow, and a runner 29 that is sloped in the same way is continuously formed at the lower end of the funnel. This runner 29 branches left and right at a gentle angle at a branch point 30 midway, forming a branch runner 31, forming a smooth curve and leading to both sides of the lower part of the space 27.

Further, the upper end of the cavity 27 is opened as it is to the upper surface of the mold 25 as a riser hole 32.

In this example, as shown in Fig. 5, the lower side of the deep funnel-shaped spout 28, that is, the lower side in the direction perpendicular to the center line of the runner 29 (the right side when facing Fig. 5)
If the molten metal 33 is injected so that there is a gap on the opposite side where gas and air can escape, the molten metal 33 flows smoothly along the runner 29, and splits from the branch point 30 into a branch runner 31. The molten metal flows into both sides of the lower end of the cavity 27, and the surface of the molten metal rises within the cavity 27, reaches the upper end of the feeder hole 32, and solidifies, forming the feeder portion 34 and the bent pipe 35. Further, the test piece 50 is obtained by recessing a part of the cavity 27 to form a recess 51.

Thereafter, the mold 25 and core 26 are broken to take out the cast product, and the runner and riser portion are removed to obtain the product.

7 and 8 show an example of casting a branch pipe, and in this case too, the casting cavity 37 formed by the casting 36 and the core 48 is inclined at a predetermined angle with respect to the horizontal plane.

38 is a deep funnel-shaped spout, followed by runner 3
The spout 38 and the runner 39 are provided in two sets.

In this embodiment, the inclination angle of the cavity 37, spout 38, and runner 39 is about 60 degrees with respect to the horizontal plane.

Each runner 39 is branched left and right at a gentle angle from a branch point 40 in the middle to form a branch runner 41, and this runner 41 forms a smooth curve to form the empty space 3.
7 and the branch 49 of the cavity 37 . In addition, in the empty space 37, there is a recess 4 for creating a hanging hand.
2, but gas vent holes 43 are provided in all of these recesses 42. Further, a feeder hole 44 is formed at the upper end of the cavity 37.

In this example as well, if the molten metal 45 is simultaneously injected along the lower side of each deep funnel-shaped spout 38 as shown in FIG. From point 40, the molten metal flows into each branch runner 41 into the cavity 37, and the surface of the molten metal rises within the cavity 37, reaches the upper end of each feeder hole 44, and solidifies to form a branch pipe 46.

Thereafter, the mold 36 and core 48 are broken, the cast product is taken out, and the runner section and feeder section 47 are removed to obtain a product.

The method of this invention is to form a casting cavity in a mold so that the product is cast at a steep angle with respect to the horizontal plane, as in each of the above embodiments, and a runner provided in this mold has a steep runner at the upper end of the mold. The spout is inclined from the angled spout and curved into a smooth arc shape, and this runner is branched into multiple parts to reach the lower end of the casting cavity. Casting is performed by using a mold with a feeder hole that opens at the top, and pouring molten metal along the lower part of the spout from a deep funnel-shaped spout that is steeply inclined at the top of the mold. Therefore, when pouring molten metal into the spout during casting, gas and air in the spout and the runners around the spout are quickly discharged, and the runner does not have to be bent at right angles as in conventional methods. After the liquid quickly descends through the inclined runner and flows into the lower end of the casting cavity without encountering any resistance, the liquid level rises in the cavity. will be inclined with respect to the empty space.

For this reason, compared to conventional vertical molds, the surface area of the liquid inside the cavity is wider, which has a greater degassing effect, and allows the molten metal to flow through the runners with less resistance, resulting in superior quality castings without cavities. can get.

[Brief explanation of the drawing]

Fig. 1 is a cross-sectional plan view showing an example of a conventional bent pipe in a cast state, Fig. 2 is a developed vertical cross-sectional view taken along line A-A in Fig. 1, and Fig. 3 is an example of a conventional branch pipe in a cast state. 4 is a vertical sectional view taken along the line B--B in FIG. 3, FIG. 5 is a vertical sectional front view of a bent pipe cast according to the method of this invention, and FIG. 6 is a vertical sectional view taken along the line C--C in FIG. 5. FIG. 7 is a longitudinal sectional view of a branch pipe cast according to the method of the present invention, and FIG. 8 is a longitudinal sectional view taken along the line D--D in FIG. 7. 25, 26... Mold, 26, 48... Core, 27,
37...Casting space, 28,38...Spout, 29,3
9... runner, 30, 40... branching point, 31, 41... branching runner, 32, 44... riser hole.

Claims (1)

[Claims] 1 A casting cavity is formed at a steep angle in the mold so that the product is cast at a steep angle with respect to the horizontal plane, and a runner provided in this mold is also formed at a steep angle from the spout at the upper end of the mold. The runner is provided in an inclined shape and curved in a smooth arc shape, and this runner is branched into a plurality of parts to reach the lower end of the casting cavity, and a riser opening into the upper part of the mold is provided at a suitable position at the upper end of the casting cavity. Using a mold with holes and a deep funnel-shaped spout that slopes along with the runner at the upper end of the runner, molten metal is poured along the lower side of the funnel-shaped spout.
A casting method characterized by casting in such a way that molten metal flows along the low side of the runner, and gas escapes into the atmosphere from the high side of the runner to the high side of the spout.