JPH0442035Y2 - - Google Patents

Description

[Detailed description of the invention] (Industrial application field) This invention is applicable to, for example, a sand supply device for a molding machine that blows and supplies foundry sand with compressed air to the molding space in a mold for molding a bore core. Regarding.

(Prior art) Conventionally, as a sand supply device for the above-mentioned molding machine,
For example, there is a device having a structure as shown in FIG.

That is, a blow tank 42 integrally provided with a blow head 41 at the lower part is provided, and a sand supply tube 43 is provided that appropriately faces the upper end 42a of this blow tank 42, and is movable in the horizontal direction at the bottom of this sand supply tube 43. The opening/closing shutter 44 is attached to the opening/closing shutter 4, and molding sand is pumped with compressed air from a sand supply source (not shown) such as a sand reservoir.
4, open the sand supply cylinder 43, blow tank 42,
This sand supply device is configured to blow sand into a predetermined molding space of a molding machine through the blow head 41 in this order.

However, the conventional device described above has the following problems.

In other words, the above-mentioned opening/closing shutter 44 receives sand pressure from above and also moves horizontally with respect to the shutter opening/closing opening 45 of the sand supply tube 43, so that sand can be trapped between the opening/closing shutter 44 and the shutter opening/closing opening 45. The above-mentioned opening/closing shutter 44 operates with sand trapped between the two 44 and 45.

As a result, the above-mentioned opening/closing shutter 44 and sand supply tube 43 are significantly worn, and both of them 43,
44 had the problem of poor durability.

(Purpose of the invention) This invention is a sand supply device for a molding machine that eliminates sand leakage by ensuring that the on-off valve closes without causing wear on the on-off valve and the members that the valve faces. The purpose is to provide.

(Structure of the invention) This invention is a sand supply device for a molding machine that supplies sand from a sand supply source to a blow tank of a molding machine through a supply cylinder, and is movable up and down with respect to the supply cylinder.
and an intermediate cylinder having a diameter larger than the diameter of the supply cylinder, a drive device for raising and lowering the intermediate cylinder, a sand pressure prevention member provided in the upper part of the intermediate cylinder and having a smaller diameter than the intermediate cylinder, and the sand pressure prevention member. A sand supply device for a molding machine, which includes an on-off valve that is elastically installed on a member and brings a lower end tapered portion into contact with a tapered stopper of an intermediate cylinder, and a plunger that comes into contact with the blow tank and pushes up the on-off valve. It is characterized by

(Effects of the invention) According to this invention, when the on-off valve is in the closed state, when the blow tank is brought into contact with the plunger and the on-off valve is pushed up through the plunger, sand from the sand supply source flows into the supply cylinder and It is supplied to the blow tank via an intermediate cylinder.

Furthermore, when the intermediate cylinder is raised by the above-mentioned drive device from the valve open state, the sand pressure prevention member at the upper part of the intermediate cylinder pushes the sand inside the intermediate cylinder upwards to prevent downward sand pressure. At the same time, the on-off valve elastically installed on the sand pressure prevention member moves downward, and the tapered lower end of the on-off valve comes into contact with the tapered stopper of the intermediate cylinder, resulting in a closed state.

In this way, when the valve is closed, the above-mentioned sand pressure prevention member prevents sand pressure from being applied downward, so the on-off valve is not subjected to sand pressure from above, and as a result, the on-off valve can be closed reliably. It is effective in eliminating sand leakage.

In addition, the opening/closing of the lower end taper part of the above-mentioned on-off valve and the tapered stopper of the intermediate cylinder corresponding to the valve seat is performed by vertical relative movement, and sand is not caught between these two, so the on-off valve and This has the effect of eliminating wear on the tapered stopper.

(Example) An example of this invention will be described in detail below based on the drawings.

The drawing shows a sand supply device for a molding machine, and in FIG. 1, a fixed base 2 with an opening 1 is provided, and a sand introduction gap 3 is erected and fixed on the opening 1 of this fixed base 2, and the sand introduction A cap 4 is screwed into the upper end opening of the tube 3.

Further, a sand pressure feed pipe 5 is provided which communicates with the intermediate portion of the sand introduction pipe 3 described above, and a sand supply source (not shown) such as a sand reservoir is connected to the base end of the sand pressure feed pipe 5.

Furthermore, a sand supply cylinder 6 is fixed to the lower surface of the opening 1 of the fixed base 2 by bolts.

In addition, a bracket 7 is fixed to the lower surface of the fixed base 2 on the side of the sand supply cylinder 6, while a cylinder mounting plate 8 fixed upright on the fixed base 2 is connected to a drive device via a cylinder holder 9. A cylinder 10 is installed.

A swing lever 14 is suspended between a connecting pin 12 at the tip of the piston rod 11 in the cylinder 10 and a support shaft 13 provided at the lower end of the bracket 7 mentioned above.

On the other hand, a slider 15 that moves up and down along the outer circumference of the sand supply tube 6 is provided, and a pin 16 protruding outward from the outer circumference of the slider 15 is inserted into the elongated hole of the swing lever 14. 17, and the above-mentioned slider 15 is raised and lowered by operating the cylinder 10.

An intermediate cylinder 19 having a larger diameter than the sand supply cylinder 6 is welded to the lower part of the flange 18 bolted to the lower surface of the slider 15, and a sand supply port 20 is provided at the lower part of the intermediate cylinder 19. A tapered stopper 21 serving as a valve seat is screwed together.

Furthermore, a sand pressure prevention member 23 having a diameter smaller than that of the intermediate cylinder 19 is fixed to the upper part of the intermediate cylinder 19 through a plurality of spokes 22 .

This sand pressure prevention member 23 has a cylindrical portion 2 with an open bottom.
Conical part 23b set to the angle of repose of sand at the top of 3a
An on-off valve 25 is connected to the cylindrical portion 23a of the sand pressure prevention member 23 via a compression spring 24.
has been established.

The above-mentioned on-off valve 25 has a piston member 25a provided in a cylindrical portion 23a so as to be movable up and down, and a rubber member 25b integrally joined to the lower surface of the piston member 25a. A lower end tapered portion 25c corresponding to the tapered stopper 21 is formed.

Further, a plunger 27 for pushing up the on-off valve 25 against the spring force of the compression spring 24 is installed in the sand receiving tube 29 of the blow tank 26 facing the lower end of the above-mentioned on-off valve 25 .

The above-mentioned blow tank 26 is connected to the inner pipe 2
A sand receiving cylinder 29 is screwed to the upper end of the blow tank 26, and a guide cylinder 31 is screwed to the upper end of the outer pipe 30.A blow head (not shown) is integrally fixed to the lower part of the blow tank 26. The molding sand, which is supplied under pressure from the sand receiving cylinder 29 through the inner pipe 28, is blown into a predetermined molding space in the mold through the blow head.

The illustrated embodiment is configured as described above,
The action will be explained below.

In the closed state of the on-off valve 25 shown in FIG.
When the blow tank 26 is operated in the direction of arrow a in the figure, the plunger 27 fixed to the sand receiving tube 29 of the blow tank 26 moves upward, and the plunger 27 releases the spring of the compression spring 24 as shown in FIG. Push up the on-off valve 25 against the force.

As shown in FIG. 2, when the above-mentioned on-off valve 25 opens, a sand supply source such as a sand reservoir (not shown) is opened.
The foundry sand S from each element 5, 3, 1, 6, 19,
20, as shown by the arrow in the figure, from the sand receiving tube 29 of the blow tank 26 to the inner pipe 28 by its own weight, and then the blow tank 2
6 is supplied to a predetermined molding space in the mold via a blow head (not shown) at the bottom.

Next, when the piston rod 11 of the cylinder 10 is operated in the direction of the arrow b in the figure from the valve open state shown in FIG.
4 moves counterclockwise, the slider 15 and the intermediate cylinder 19 rise.

At this time, the lower end tapered portion 25c of the rubber member 25b of the on-off valve 25 elastically installed on the sand pressure prevention member 23 is brought into pressure contact with the tapered stopper 21 of the intermediate cylinder 19 due to the spring force of the compression spring 24. , the sand supply port 20 is closed.

Moreover, as the intermediate cylinder 19 rises, the sand pressure prevention member 23 rises integrally with the intermediate cylinder 19, so the sand pressure prevention member 23 pushes up the molding sand S inside the intermediate cylinder 19, Prevent sand pressure from acting downward.

At this time, the molding sand S pushed up is pushed into a gap 32 (see FIG. 3) formed between the outer surface of the sand supply tube 6 and the inner surface of the intermediate tube 19.

As a result, the above-mentioned on-off valve 25 is not subjected to sand pressure from above, so that the on-off valve 25 can be closed reliably, and there is an effect that sand leakage can be eliminated.

In addition, the lower end tapered portion 25 of the above-mentioned on-off valve 25
c and the tapered stopper 21 of the intermediate cylinder 19, which corresponds to the valve seat, are opened and closed by vertical relative movement, and since almost no sand gets caught between these two 25c and 21, the on-off valve 25 and the tapered stopper 21 This has the effect of eliminating wear on the stopper 21 and improving durability.

Regarding the correspondence between the structure of this invention and the above-mentioned embodiment, the supply cylinder of this invention corresponds to the sand supply cylinder 6 of the embodiment, and similarly, the sand corresponds to the foundry sand S, and the drive device is: Although the present invention corresponds to the cylinder 10, it is not limited to the configuration of the above-described embodiment.

[Brief explanation of the drawing]

The drawings show one embodiment of this invention, and Fig. 1 is a sectional view showing the sand supply device of the molding machine, Fig. 2 is an explanatory view when sand is being supplied, Fig. 3 is an explanatory view when the valve is closed, and Fig. 4 is an explanatory view when the valve is closed. The figure is a schematic diagram of a conventional sand supply device. 6...Sand supply cylinder, 10...Cylinder, 19...
Intermediate cylinder, 21...Tapered stopper, 23...Sand pressure prevention member, 25...Opening/closing valve, 25c...Lower end tapered portion, 26...Blow tank, 27...Plunger, S...Casting sand.

Claims (1)

[Scope of Claim for Utility Model Registration] A sand supply device for a molding machine that supplies sand from a sand supply source to a blow tank of a molding machine through a supply cylinder, which is movable up and down with respect to the supply cylinder, and an intermediate cylinder having a diameter larger than the diameter of the cylinder; a drive device for raising and lowering the intermediate cylinder; a sand pressure prevention member provided in the upper part of the intermediate cylinder and having a smaller diameter than the intermediate cylinder; and an elastic force for the sand pressure prevention member. A sand supply device for a molding machine, comprising: an on-off valve that brings a lower end tapered portion into contact with a tapered stopper of an intermediate cylinder; and a plunger that comes into contact with the blow tank and pushes up the on-off valve.