JPH0543975Y2 - - Google Patents

Description

[Detailed description of the invention] (Field of industrial application) The invention is based on the invention, which feeds a molten low-melting point metal held in a holding furnace under pressure to a mold placed outside the machine to form a core of the low-melting point metal. The present invention relates to a pressurized feeding device for casting molten metal.

(Prior art and its problems) In recent years, cores cast from low-melting point metals have been increasingly used to manufacture hollow bodies with complex shapes. A plunger-type pressurized molten metal feeding device is used in which a plunger cylinder is immersed in molten metal in a holding furnace, and a plunger piston feeds the molten metal in the plunger cylinder to the mold via a nozzle. It is common to

On the other hand, many low-melting point metals contain bismuth, which has the property of expanding during solidification.If the holding furnace of the molten metal pressurized feeding device stops heating due to a power outage or other abnormality, As the molten metal solidifies in the holding furnace, the molten metal in the plunger cylinder also solidifies and expands. Therefore, when the plunger piston is at the rising end, there is a problem in that excessive force is applied to various parts of the plunger cylinder, deforming or damaging the device.

(Purpose) The present invention was developed in view of the above-mentioned problems.It is an object of the present invention to provide a pressurized molten metal feeding device that does not damage the plunger device even when the heating of the molten metal by the heater of the holding furnace is stopped. This is the purpose.

(Structure) The structure of the present invention will be explained in detail below using illustrated examples.

Reference numeral 1 denotes a holding furnace equipped with a heater (not shown). Inside the holding furnace 1, a cylinder tube 2 is arranged vertically via a support member (not shown), and a pressurizing piston is installed in the cylinder tube 2. 3 are fitted in a vertically slidable manner.

A downward cylinder 5 is provided at a position directly above the cylinder tube 2 above the holding furnace 1 via a frame 4, and a mounting plate 6 is fixed to the lower end of the piston rod 5a.

A guide tube 8 is fixed to the lower part of the mounting plate 6 and has a stepped hollow hole 7 with a large diameter at the top and a small diameter at the bottom, and the stepped hollow hole 7 has a T-shaped connection at its upper end. A rod 9 is penetratingly inserted and suspended so as to be movable up and down, and the lower end of the connecting rod 9 is fixedly connected to the upper surface of the pressure piston 3.

Further, a coil spring 10 whose repulsive force is larger than the output of the downward cylinder 5 is provided between the upper end of the connecting rod 9 in the large diameter portion of the stepped hollow hole 7 and the mounting plate 6. equipped. Furthermore, a first nozzle 11 extending horizontally is connected to the bottom of the cylinder tube 2 with one end communicating with the first nozzle 11. A communicating second nozzle 13 is connected.

In the figure, 14 is a molten metal introduction hole, and 15 is a low melting point metal in a molten state (hereinafter referred to as molten metal).

Further, in FIG. 1, the pressurizing piston 3 is positioned at the rising end due to the upward movement of the downward cylinder 5, and the upper end of the connecting rod 9 is in contact with the stepped portion of the stepped hollow hole 7, and the upper end of the connecting rod 9 is in contact with the stepped portion of the stepped hollow hole 7. It is prevented from rising by the repulsive force.

In this state, the coil spring 10 is in a state where it can be compressed to a length greater than the vertical solidification expansion amount of the molten metal 15 in the cylinder tube 2.

(Function) The structure configured as described above is shown in FIG.
The nozzle 13 is filled with molten metal 15 up to its upper position.

In this state, the downward cylinder 5 operates to lower the pressure piston 3 and feed the second nozzle 13, the first nozzle 11, and the molten metal 15 in the cylinder tube 2 under pressure to the mold 12. Delivered molten metal 1
Hold until 5 solidifies. The portion of the second nozzle 13 exposed from the holding furnace 1 is heated by a heater (not shown) so that the molten metal in this portion does not solidify.

Next, the downward cylinder 5 operates in reverse to raise the pressure piston 3 to the position shown in FIG. The above operation is possible because the repulsive force of the coil spring 10 is greater than the output of the downward cylinder 5.
The connecting rod 9 and the connecting rod 9 are moved up and down as one body. When the pressurizing piston returns to the state shown in FIG. 1, the molten metal 15 is introduced into the cylinder tube 2 through the molten metal introduction hole 14, and its level is returned to the level before the operation.

Next, the core cast in the mold 14 is taken out, and necessary operations such as mold cleaning and mold matching are performed to restore the state shown in FIG. 1, and the same casting operation is repeated.

In the state shown in FIG. 1, if heating by the heater stops in the holding furnace 1 due to power outage, wire breakage, or other abnormality, the molten metal 15 in the holding furnace 1 will solidify and the molten metal 15 in the cylinder tube 2 will also solidify and expand. to push the pressurizing piston 3 upward. Accordingly, the connecting rod 9 compresses the coil spring 10 against the repulsive force of the coil spring 10 and rises, thereby avoiding deforming or damaging the cylinder tube 2, the downward cylinder 5, etc.

At this time, the force applied to the device is only that of the compression of the coil spring 10, so the force is not large and does not damage the device.

In the above embodiment, the coil spring 10 is resiliently mounted within the guide cylinder 8, but the same effect can be obtained even if the spring member is replaced with a disc spring, a rubber spring, or the like.

(Effects) As is clear from the above description, the present invention connects the connecting rod to the tip of the piston rod of the cylinder for lifting and lowering the pressurized piston fitted in the cylinder tube via a resilient spring member. Because of the connected configuration, even if the heating of the heater in the holding furnace is stopped and the low melting point metal solidifies and expands, there is an excellent effect that no damage is caused to the device.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention, and FIG. 1 is a longitudinal sectional view, and FIG. 2 is an enlarged view of section A in FIG. 1. 1... Holding furnace, 2... Cylinder tube, 3... Pressurizing piston, 5... Downward cylinder, 5a... Piston rod, 6... Mounting plate, 7... Stepped hollow hole, 8
... Guide cylinder, 9 ... Connection rod, 10 ... Coil spring.

Claims (1)

[Scope of utility model registration request] A cylinder tube 2 is arranged in a holding furnace 1, and nozzles 11 and 13 communicating with a mold 12 arranged outside the holding furnace 2 are connected to the lower part of the cylinder tube 2, and the cylinder tube 2 is pressurized. The piston 3 is vertically slidable and fitted, and the downward cylinder 5 is positioned directly above the cylinder tube 2 above the holding furnace 1.
is fixedly installed via the frame 4, and the downward cylinder 5
A guide cylinder 8 having a stepped hollow hole 7 is attached to the tip of the piston rod 5a via a mounting plate 6, and a connecting rod 9 having a T-shaped upper end can be moved up and down into the stepped hollow hole 7. At the same time, the lower end of the connecting rod 9 is connected to the pressurizing piston 3, and the downward cylinder 5 is inserted between the upper end of the connecting rod 9 in the stepped hollow hole 7 and the mounting plate 6. A molten metal pressurized feeding device characterized by being elastically loaded with a spring member 10 having a repulsive force larger than the output.