JPH0242374Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to an improvement of a low-pressure casting machine in which the mold cavity is filled with an inert gas such as argon gas or nitrogen gas before pouring.

(Prior Art and Problems) In low-pressure casting, it is known to fill a mold cavity with an inert gas before injecting molten metal into the mold cavity in order to improve the quality of the product. By the way, the mold of a low-pressure casting machine is equipped with an extrusion pin mechanism that releases the product from the mold, so the mold device must be kept airtight to prevent the inert gas supplied to the mold cavity from leaking outside. If you try to enclose the mold cavity, there is a problem that the entire low-pressure casting machine becomes large-scale and expensive, and for this reason, it has not been done in the past to fill the mold cavity with inert gas before pouring the metal. .

(Purpose of the invention) This invention was made in view of the above circumstances.
It is an object of the present invention to provide a low-pressure casting machine configured to fill a mold cavity with inert gas by means of a simple structure.

(Structure of the invention) Hereinafter, the structure of the invention will be described in detail based on drawings of embodiments. 1 is a lower platen installed on a holding furnace (not shown), and a lower mold 2 is attached to the center of the upper surface of the lower platen 1 via a lower skirt member 3, and the lower mold 2 and the lower skirt are connected to each other. The upper surface level is the same as that of member 3. A pouring hole 4 is formed in the center of the lower cavity portion 2a of the lower mold 2, and the lower end of the pouring hole 4 is connected to the upper end of a stalk pipe 5 extending downward. In addition, the pouring hole 4 has a vent plug 6,
It is connected to an inert gas generation source (not shown) via a communication hole 7, piping 8, and an on-off valve (not shown). 9 is the guide rod 1 above the lower mold 2.
0 and 10, and the upper platen 9 is connected to a piston rod 12 of a downward cylinder 12 fixed to a frame 11.
The piston rod 12 of the cylinder 12 is attached to the lower end of the cylinder 12 via a connecting member (not shown).
It is designed to rise and fall by contracting and expanding a. Note that the guide rods 10, 10 are connected to the frame 11.
It is fitted through holders 13, 13 which are fixedly installed in such a manner that it can freely slide upwardly and downwardly. Further, on the lower surface of the upper platen 9, an upper mold 15 equipped with a product extrusion mechanism 14 faces the lower mold 2 and is attached via an upper skirt member 16, and the upper mold 15 and the upper skirt member The lower surface level is the same as No. 16. The product extrusion mechanism 14 includes extrusion pins 18, 18 and return pins 19, 19 that are fitted into the upper mold 15 so as to be able to move up and down;
18 and an extrusion plate 17 installed between the upper ends of return pins 19 and 19. Guide bars 21, 21 are vertically vertically slidably and airtightly penetrated through the upper platen 9 via holders 20, 20 on the extrusion plate 17.
A connecting plate 22 is installed between the upper ends of the members 1 and 21.

Further, on the upper cavity part 15a surface of the upper mold 15, a plurality of communication holes 23 into which vent plugs are fitted,
23 is provided transparently.

Further, a space 24 defined by the upper platen 9, the upper skirt member 16, and the upper mold 15 is occupied by the piping 2.
5 and a vacuum pump (not shown) via an on-off valve (not shown). Reference numeral 26 denotes a backing plate attached to the frame 11, and is adapted to come into contact with the connecting plate 22.

(Operation of the device) Next, the operation of the device configured as described above will be explained. In the state shown in the figure, the pressure inside the holding furnace (not shown) is reduced, and suction is applied via the pipe 25 to the space 24 and the upper and lower cavity parts 15.
When the pressure inside a and 2a is reduced and then inert gas is supplied to the communication hole 7 via the pipe 8, the inert gas enters the pouring hole 4 through the vent plug 6.
The inert gas that has entered the pouring hole 4 rises therein and enters the upper and lower cavity portions 15a, 2a and the space 24 and is filled therein. After filling the upper and lower cavity parts 15a, 2a and the space 24 with inert gas,
The supply of inert gas is stopped, and then a normal low-pressure casting process is performed to fill the upper and lower cavity parts 15a and 2a filled with inert gas with a predetermined molten metal.
After the molten metal solidifies, the piston rod 1 of the cylinder 12
2a is shrunk and the upper mold 1 is passed through the upper platen 9.
5. When the product extrusion mechanism 14 and the like are raised, the upper mold 15 is raised with the solidified metal attached thereto. During this rise, the product receiver is carried under the upper mold 15, and when the rise continues and the connection plate 22 of the product extrusion mechanism 14 comes into contact with the backing plate 26, the ejection pins 18, 18 are Upper mold 1
5, the solidified metal is pushed out from the upper cavity part 15a of the upper mold 15, dropped into the product receiver, and carried out together with the product receiver. Next, the piston rod 12 of the cylinder 12
By extending a, the upper mold 15 and the product extrusion mechanism 14
etc. are shown in their original state as illustrated. In this case, the lower skirt member 3 and the upper skirt member 16 are brought into close contact with each other.

(Effects of the invention) As is clear from the above explanation, the present invention mounts the lower mold 2 on the lower platen 1 via the lower skirt member 3, and inactivates the pouring hole 4 of the lower mold 2. An upper mold 15 connected to a gas generation source and equipped with a product extrusion mechanism 14 is attached to the lower surface of the upper platen 9 via an upper skirt member 16, and a ventilation hole 23 is provided on the surface of the upper cavity portion 15a of the upper mold 15. Transparent,
A space 24 defined by the upper platen 9, the upper mold 15, and the upper skirt member 16 is connected to a vacuum pump, and guide bars 21, 21 are connected to the upper platen 9.
The guide bar 21,
21 and the product extrusion mechanism 14 are connected, the upper and lower molds 15 and 2 are aligned, and the vacuum pump is driven to reduce the pressure in the upper and lower cavity parts 15a and 2a. By simply supplying inert gas, the upper and lower cavity parts 15a and 2a can be filled with inert gas, and the entire device has a simple structure and is inexpensive, providing excellent practical effects. .

[Brief explanation of the drawing]

The drawing is a longitudinal sectional view of the main part of the present invention. 1: Lower platen, 2: Lower mold, 2a: Lower cavity, 3: Lower skirt member, 4: Pouring hole, 6:
Vent plug, 7: Communication hole, 8: Piping, 9: Upper platen, 14: Product extrusion mechanism, 15: Upper mold,
15a: upper cavity part, 16: upper skirt member, 23: ventilation hole, 24: space, 25: piping.

Claims (1)

[Scope of utility model registration request] A lower mold 2 having a lower cavity portion 2a and a pouring hole 4 is attached to the upper surface of a lower platen 1 disposed on a holding furnace via a lower skirt member 3, and the pouring hole 4 of the lower mold 2 is attached. An upper platen 9 is connected to an inert gas generation source through a vent plug 6, a communication hole 7 and a pipe 8, and is disposed above the lower mold 2 so as to be movable up and down, and on the lower surface of the upper platen 9, It has an upper cavity part 15a and a product extrusion mechanism 1.
an upper mold 15 attached with 4 is mounted opposite to the lower mold 2 via an upper skirt member 16;
A communication hole 23 for fitting a vent plug is provided in the upper cavity part 15a surface of the upper mold 15, and a space 24 defined by the upper platen 9, the upper mold 15, and the upper skirt member 16 is connected to a pipe 25. A low-pressure pump is connected to a vacuum pump through a vacuum pump, guide bars 21, 21 are vertically movably passed through the upper platen 9 in an airtight manner, and the guide bars 21, 21 are connected to the product extrusion mechanism 14. Casting machine.