JPH024765Y2 - - Google Patents

Description

[Detailed description of the invention] [Technical field to which the invention pertains] The invention is based on a method that connects the air in a cavity in a mold attached to a die-casting machine to a vacuum source and evacuates it, or when releasing it to the atmosphere. Regarding the vacuum/exhaust equipment provided.

[Prior art]

Conventionally, there are two types of vacuum/exhaust devices that release the air inside the mold cavity to the atmosphere and create a vacuum. The molten metal cooled and solidified in this area after it was filled, so the molten metal did not flow out, but the air flow resistance was large and it was not possible to exhaust the air sufficiently. The second quick shaft type has a valve etc. in a wide exhaust passage and closes it with a cylinder etc. when the cavity is filled with molten metal, so the exhaust passage is wide and the air flow resistance is small, but it is difficult to close the valve etc. If the timing is too early, sufficient evacuation will not be possible, and if the valves are closed too late, the molten metal will flow out.

[Purpose of invention]

The present invention eliminates these drawbacks, and its purpose is to reduce exhaust resistance and enable sufficient exhaust by utilizing only the good parts of the two methods mentioned above, and to prevent the molten metal from flowing out to the outside. It is an object of the present invention to provide a vacuum/exhaust device for a die-casting mold that prevents this from occurring.

[Key points of the idea]

The vacuum/exhaust device for die-casting molds in the present invention includes one side insert fixed to one side of the mold and one side insert fixed to the other side of the mold on the opposing surfaces of a fixed mold and a movable mold. It consists of an insert on the other side that is moved by a cylinder fixed to the mold on the other side to approach or separate from the mold, and a labyrinth-like exhaust path formed on the opposing surfaces of the pair of inserts. , one end of the exhaust path is connected to the cavity, and the other end is connected to the exhaust ports formed in both molds.

[Example of idea]

The present invention will be explained below with reference to figures showing embodiments. Reference numerals 11 and 12 denote molds, and although either may be a fixed mold or a movable mold, the explanation will be made assuming that 11 is a fixed mold. A cavity 13 and a recessed portion in the upper part of the figure are formed on opposing surfaces of both molds 11 and 12. An A insert 14 is fixed to the movable mold 12 on the movable mold 12 side of the recess, and a B insert 15 placed on the fixed mold 11 side is a piston 17 of a cylinder 16 fixed to the fixed mold 11. By being attached to the tip of the A insert 14, it is made to be close to or separated from the A insert 14. A labyrinth-like exhaust passage 18 made of overlapping triangular shapes is formed on the opposing surfaces of both inserts 14 and 15, one end of which communicates with the cavity 13, and the other end an exhaust port formed on the opposing surfaces of both molds 11 and 12. It is connected to 19. Exhaust port 19
is connected to a vacuum source (not shown) in the case of vacuum die casting, and is exposed to the atmosphere as shown in the figure in the case of normal die casting. Note that the exhaust path 18 may be formed into overlapping circular arcs or a rectangular shape other than that shown in the drawings, and the exhaust path 18 does not need to be straight.

Next, the operation of the embodiment described above will be explained.

Until the molten metal reaches the end of the cavity 13 (the upper end in the figure) from the plunger sleeve (not shown), the B insert 15 is placed in a position with the exhaust passage 18 wide, with the B insert 15 to the right compared to the state shown in the diagram, and the molten metal reaches the end of the cavity 13. When it reaches the position, pressure fluid is sent to the right chamber of the cylinder 16 to move the B insert 15 to the left to the illustrated position.

In this way, when the B insert 15 moves to the left and the exhaust path 18 narrows, the molten metal flowing there contacts both inserts 14 and 15 and is rapidly cooled and solidified, causing the molten metal to flow into the vacuum source or into the atmosphere. Prevent it from gushing. Note that the distance between the wide and narrow exhaust passages 18 is appropriately selected depending on the shape and size of the die-cast product, and the amount is determined by controlling the stroke of the piston 17 of the cylinder 16.

[Effect of idea]

As explained above, the vacuum/exhaust device for the die-casting mold according to the present invention makes one side of the two inserts that form the exhaust path movable, widens the exhaust path when expelling air, and allows the molten metal to The configuration was such that the cavity was narrowed when it was full. Therefore, the exhaust gas is sufficiently exhausted, and even if the time when the exhaust path is narrowed is delayed, there is an advantage that there is no risk of the molten metal flowing out because the exhaust path is maze-like.

[Brief explanation of the drawing]

The figure is a sectional view of one embodiment of the present invention. DESCRIPTION OF SYMBOLS 11... Fixed mold, 12... Movable die, 13... Cavity, 14, 15... Insert, 16... Cylinder.

Claims (1)

[Scope of utility model registration request] One side of the mold is fixed to the one side of the mold on opposing surfaces of the fixed mold and the movable mold, and the other side of the mold is moved toward or away from the one side of the mold on the other side. It consists of an insert on the other side that is moved by a cylinder fixed to the mold, and a labyrinth-shaped exhaust path formed on the opposing surfaces of the pair of inserts, one end of which is connected to the cavity. a vacuum/exhaust device for the die-casting mold, the other end of which is connected to the exhaust ports formed in both the molds;