JPH0332446A - Device and method for stacking molding mold - Google Patents

Abstract

PURPOSE:To disperse heat expansion at the time of pouring molten metal and to prevent breakage of a green sand mold by constituting stacking device for molded molds of shifting part for molded mold, taking-out part for flask and mold piling part. CONSTITUTION:The mold 8 with flask is held with a flask holder 6 rotated with rotating shaft and shifted to the piling part 4. Successively, the mold 8 is stood still on supplying table 10, and by descending a pushing-out plate 12, the mold 8 is pushed out from the flask 9 to make the molded mold 13 without flask. At the time of laying this mold 13 on a plate 14, the plate 14 is descended with a lifter 16 by distance corresponding with the thickness of the mold 13. When this movement is completed, the next flask holder 6 is shifted to the piling part with rotation of the rotating shaft and the next molded mold 8 with flask is laid on a supporting table 10. When movement of the flask holder 6 is interrupted, the pushing-out plate 12 is descended to take off the mold 13 from the flask 9 and the fresh mold is piled on the mold 13 without flask on the plate 14.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a stacking device and a method for stacking molds.

(Prior art) As disclosed in Japanese Utility Model Publication No. 57-36353,
Alternatively, small castings of approximately the same shape or thin castings such as piston rings are usually made in one green sand mold with multiple cavities, and the mold is stacked vertically with a runner formed in the center of the mold. The stack mold method, in which the channels are arranged vertically and molten metal is supplied from the sprue to fill the lowest cavity first, and then sequentially fills the cavities from the bottom to the top, can fill a large number of metals at once in - times of pouring. Since it has various advantages in terms of productivity, such as the ability to obtain individual casting materials, it is commonly used when mass producing small castings.

The molds used in this stack molding method are either flasked or unframed, and in the case of a flask mold, one flask is required for each mold, so a large number of flasks must be prepared. It won't happen. In addition, the flasks are subject to wear and tear, requiring a large number of flasks to be kept in stock at all times, and care must be taken to control their dimensions, making their maintenance difficult.

After pouring, the flask must be dismantled and all flasks must be transported to the vicinity of the molding machine, resulting in poor work efficiency. Therefore, it is possible to use a frameless mold.

(Problems to be Solved by the Present Invention) The mold used in the stack mold method is a green sand mold. As is well known, green sand molds are made by compacting foundry sand mixed with appropriate amounts of binders and other additives. On the other hand, the mold used in the stack mold method has cavities at the tips of multiple runners extending radially outward from the runner at the center of the mold. The dimensions with respect to the surface are smaller. In the conventional stack molding method, the center of the cavity in each mold is in a straight line in the vertical direction, so the small-sized portions described above exist from top to bottom.

A green sand mold has a small amount of sand on its outer circumferential side, and its strength is weak. Since the small-sized portion described above is a weakly strong portion, there is a high risk that the small-sized portion will be destroyed by thermal expansion during pouring, and the molten metal will elute to the outside. For this reason, it is difficult to adopt the stacking method of frameless molding using green sand.

Therefore, it is an object of the present invention to solve the above-mentioned problems of the prior art.

(Means for Solving the Problems) In order to solve the above-mentioned problems, the present invention provides a plate for receiving the lower part of stacked molding molds, a lifter for supporting the plate and rotating the plate, and a lifter for supporting the plate and rotating the plate. The present invention provides a stacking device for forming molds having a carriage for receiving the plate and the forming mold thereon during lowering of the plate and the forming mold.

Furthermore, the present invention provides a stacking method for molds that are vertically stacked and have at least a portion in which the center positions of cavities formed in the molds are shifted in the vertical direction.

(Function) According to the present invention, the centers of the cavities formed in each mold and stacked in the vertical direction do not completely coincide from top to bottom, and a small gap between the edge of the cavity and the outer periphery of the mold is formed. Since the dimensions of the parts are not aligned in the vertical direction, thermal expansion during pouring can be dispersed and destruction of the mold can be prevented.

(Example) Referring to FIG. 1, a forming mold stacking device 1 according to an example of the present invention includes a forming mold transfer section 2, a flask removal section 3, and a mold stacking section 4. A frame-containing mold 8 having a bottom mold at a position (not shown) and having a transfer der 7 is held between frame holders 6 and transferred to the stacking section 4 as the rotating shaft 5 rotates.

The frame take-out unit 3 includes a support base 10 that receives the flask 9 of the flask-forming mold 8, and an extrusion plate 1 that is raised and lowered by a cylinder 11.
It has 2. The molding mold with a frame is transferred onto the support base 10 by the frame holder 6, and only the molding mold 13 is stacked on the plate 14 as the extrusion plate 12 is lowered. The flask 9 is lifted by the flask holder 9, rotated, and transported back to a molding section (not shown). For example, two frame holders 6 are arranged around the rotating shaft 5, so one intermittent rotation of the rotating shaft 5 sequentially stacks the molds 13.

The laminated part 4 is raised and lowered by a cylinder 15 and a lid 16
a rotating part 17 with a motor fixed to the top of the lifter 16; a plate 14 supported by the rotating part 17;
The zero rotation portion 17 having the cart 18 that receives the plate 14 has a function of rotating the plate 14 engaged therewith at a constant angle.

The outer periphery of the plate 14 is a tapered surface, and the lifter 1
6 descends, the plate 14 also descends, and when the plate 14 is about to pass through the center hole 19 of the truck 18, the tapered surface of the plate 14 seats on the edge of the center hole 19 of the truck 18 and rotates with the lifter 16. Only the moving part 17 continues to descend. The plate 14 on the trolley 18 and the laminated mold on it are:
The cart 18 transports the molten metal to the pouring section. After that, a new truck 18 is placed in a predetermined position, and the rotating part 1 is moved together with the lifter 16.
7 to the initial position and a new play on it) 1
4, this plate 14 can be rotated by a fixed angle by a rotating portion 17.

Next, the operation of the illustrated device will be described. A mold 8 with a frame formed in a molding section (not shown) is held by a frame holder 6 rotated by a rotating shaft 5 and transferred to the stacking section 4 . The frame-filled mold 8 transferred to the stacking section is placed on a support stand 10. In this state, the movement of the frame holder 6 is suspended. When the mold 8 comes to rest on the support stand 10,
The extrusion plate 12 descends to extrude the mold from the frame 9 to form a frameless mold 13. This mold 13 rests on a plate 14. When the first molding mold 13 is placed on the plate 14, a ruler 6 with a dimension corresponding to the thickness of this mold 13 is placed on the rotating shaft 5.
The rotation moves to the stacking section, and the next frame-filled mold 8 is placed on the support stand 10. When the movement of the frame holder 6 is interrupted, the extrusion plate 12 is lowered to extract the mold 13 from the frame 9, and a new mold is stacked on top of the frameless mold 13 on the plate 14. Before or during this lamination work, the rotating part 1
7 rotates the plate 14, for example, 45 degrees. As a result, the lower mold 13 and the upper mold 1 stacked together
3 means that although the center sprue is concentric, the center positions of the cavities are offset by 45 degrees from each other, and the small dimension between the end of the cavity and the outer peripheral surface of the mold is offset in the vertical direction. . When a new mold 13 is stacked, the lid 16 is lowered accordingly, and a new mold 8 is further transferred to the stacking section 4 by the frame holder 6. The rotating part 17 rotates the plate 14 again by 45 degrees, and a new mold 13 is further stacked thereon.

When the molds 13 stacked in this manner reach a predetermined number, the lifter 16 is lowered by the cylinder 15. During this lowering, the lifter 16 and the rotating part 17 move through the center hole 1 of the truck 18.
9, the outer peripheral tapered surface of the plate 14 is seated on the edge of the central hole 19, and the plate 14 and the laminated molds 13 are mounted on the carriage 18. The cart 18 is moved to the pouring section, and a new cart 18 is placed at a predetermined position in the stacking section 4.

The mold used is a green sand mold made by compacting molding sand mixed with an appropriate amount of binder and other additives, and has a sprue in the center that penetrates vertically. A plurality of cavities are formed. In the case of thin castings such as piston rings, the mold is made of upper and lower molds, a cavity is made on the lower surface of the upper mold, and the upper surface of the lower mold is a flat surface.

These cavities communicate with sprues via runners.

In FIG. 2, according to an example of the present invention, metal is poured into the central sprue 20 of a mold 13 coated with Mi, and four piston rings 2 are placed in each mold.
An example of casting 1 is shown below. The centers of each piston ring 21 are shifted from each other in the vertical direction, so that the small dimension portion 11 between the end of the cavity and the outer peripheral surface of the mold does not overlap in the vertical direction.

(Effects) Thermal expansion during pouring is dispersed to prevent the green sand mold from breaking, making stack molding possible with frameless pouring.

In addition, it is possible to prevent the mold from cracking during pouring, even when the strength is insufficient due to variations in the supply of sand during mold molding.

[Brief explanation of drawings]

FIG. 1 is a front view of an apparatus according to an example of the present invention, and FIG. 2 is a perspective view showing the state of a pouring section. In the figure = 2...Transfer section, 3...Flame removal section, 4...Stacking section, 5...Rotating shaft, 6... ...Frame holder 8...Framed mold, 9...Cast flask, 10...Support stand,
12... Extrusion plate, 13... Frameless mold, 14... Plate, 16... Lifter, 17... Rotating part , 18... Trolley.

Claims (4)

[Claims] (1) A plate that receives the lower part of the stacked molds, a lifter that supports and rotates the plate, and receives the plate and the mold above it while the lifter is lowering the plate and mold. A mold stacking device with a trolley. (2) A method of stacking molds in which the centers of the cavities formed in the molds stacked in the vertical direction have at least a portion shifted in the vertical direction. (3) The stacking method according to claim (2), wherein the mold is composed of an upper and lower mold, has a cavity on the lower surface of the upper mold, and has a flat upper surface of the lower mold. (4) The stacking method according to (2), wherein the center positions of cavities of adjacent frameless molds are shifted from each other.