JP2020082109A - Gas vent device for die casting - Google Patents

Abstract

To provide a gas vent device for die casting capable of more efficiently preventing the intrusion of fine dusts to an opening/closing valve by generating vortex flows at branch paths of a gas vent passage.SOLUTION: A gas vent passage 3 in a gas vent device for die casting at least comprises: a connection passage 31 communicating with a cavity; a pair of main passages 32 connected from a pressure receiving valve 4 to a closing valve 5 ; branch passages 33 branched respectively from the main passages 32. The gas vent passage further comprises: a first passage 331 extending from an end part of one of the branch passages 33; a second passage 332 extending from an end part of the other one of the branch passages 33; a cylindrical crossed part 333 eccentrically connecting the end part of the first passage 331 and the end part of the second passage 332 to produce vortex flows; and a confluent part 334 extending in a vertical direction of the cylindrical crossed part 333 and also communicating with the closing valve 5.SELECTED DRAWING: Figure 2

Description

DISCLOSURE OF THE INVENTION The present invention relates to a die casting degassing device in which a gas containing dust and the like generated when a molten metal enters a cavity is sucked together with air by a vacuum suction device and is discharged to the outside through the degassing path. In particular, the present invention relates to a die casting degassing device capable of preventing malfunction of an on-off valve.

As a general die casting degassing device, it is provided with a degassing path communicating with a cavity between a fixed block and a movable block. Closing valve, an opening/closing lever for transmitting the operation of the pressure receiving valve to the closing valve, an opening means for pressing the closing valve in the opening direction, and a closing valve forcibly closing the opening/closing lever during initial operation when the mold is cold And a push-out pin for pushing out excess material such as aluminum solidified in the degassing path to the outside when the mold is opened.

Further, as the gas vent path, there is a path provided with a bypass path (main path) that branches left and right from the connection path and joins again as shown in FIG. 2 of JP-A-2002-96151.
Furthermore, the present inventor proposed, as an improvement of the die casting degassing device, in Japanese Patent No. 6408845 a gas degassing route in which a bypass route (branch route) was additionally formed.

JP 2002-96151 A Japanese Patent No. 6408845

However, in Japanese Patent Laid-Open No. 2002-96151, when casting is started, the gas and air in the cavity are sucked by the vacuum suction device and discharged to the outside through the gas vent passage (exhaust passage), and the molten metal is fed into the cavity. Is filled. At this time, when the molten metal pressure coming from the inlet side of the degassing device is applied to the pressure receiving valve, the closing valve that closes via the open/close lever has aluminum and fine dust entering the gap between both sliding parts of both valves. If it is easy to get dirty, and if fine dust enters the gap between both sliding parts, the movement of both valves becomes slow and the movement of the pressure receiving valve becomes slow, and the closing function of the closing valve is likely to deteriorate. Moreover, if the molten metal enters the closing valve before the closing valve is closed due to the phenomenon of molten metal leading, a failure occurs and the casting operation is interrupted. In addition, the molten metal becomes low temperature when it reaches the degassing device, and since the low temperature molten metal tends to cling to metal, clogging occurs in both sliding parts of the pressure receiving valve and the closing valve. Since the failure occurs when the part that goes into the gap between the sliding parts, it is necessary to interrupt the casting work and remove the entered aluminum and the like each time. Furthermore, if fine dust or the like gets into the vacuum suction device from the sliding part of the closing valve, it will cause the vacuum suction device itself to malfunction and the filter will be clogged quickly, so the casting operation must be interrupted, etc. There was a problem.

On the other hand, in Japanese Patent No. 6408845, a branch passage is added to the degassing passage of the die casting degassing device in the vacuum suction device, and the molten metal passing through the branch passage has a low temperature and produces fine dust. This is a method of preventing malfunction of the on-off valve because the preceding molten metal reaches the closing valve later than the high-quality molten metal that passes through the main path and has a high temperature. In addition, a bent part is formed in the main path, and a branch path is formed over the movable block and the fixed block to lengthen the path and restrict the inflow of dust and the like flowing into the closing valve side. However, there is a problem that foreign matter easily flows into the closing valve side when the flow of the molten metal becomes faster.

An object of the present invention is to provide a die casting degassing device capable of more efficiently preventing intrusion of fine dust and the like into an on-off valve by generating a vortex flow in a branch path of the degassing path.

The present invention has been made to solve the above problems, that is, the degassing path of the die casting degassing device, a connection path communicating with the cavity, and a pair of connecting from the pressure receiving valve to the closing valve. A first route that is composed of at least a main route and a branch route that branches from the main route, and that extends from the end of one branch route; and a second route that extends from the end of the other branch route, From a cylindrical intersection for eccentrically connecting the end of the first passage and an end of the second passage to facilitate vortex flow, and a confluence portion extending in the vertical direction of the cylindrical intersection and communicating with the closing valve. Constitute. Further, it is preferable that a protrusion for causing a molten metal from the first path and a molten metal from the second path to flow along the inner wall and to generate a swirl flow is provided inside the cylindrical intersecting portion. It is preferable that the portion is formed of a cylindrical portion formed on an upper portion of the cylindrical intersection portion and a square tubular portion that communicates the cylindrical portion with the closing valve. Further, the end portion side of the first path and the end portion side of the second path may each be bent in two steps to form the fixed block.

The gas vent passage (3) according to claim 1, a connection passage (31) communicating with the cavity, a pair of main passages (32) connecting the pressure receiving valve (4) to the closing valve (5), and the main passage. A first path (331) that is composed of at least a branch path (33) branching from the path (32) and extends from an end of one branch path (33), and an end of the other branch path (33). A second path (332) extending from the portion, a cylindrical intersection (333) for causing an eddy current by eccentrically connecting the end of the first path (331) and the end of the second path (332), and It is composed of a merging portion (334) extending in the vertical direction of the cylindrical intersection portion (333) and communicating with the closing valve (5), so that the temperature passing through the branch passage (33) is low and contains fine dust. Since the pre-melted metal solidifies as a pool without reaching the closing valve (5), fine dust such as aluminum is prevented from entering the sliding part of the closing valve (5) during casting. Since it is possible, the close valve (5) can be completely closed tightly, the malfunction of the pressure receiving valve (4) and the close valve (5) is hardly caused, and the casting work which has conventionally occurred. There is no need to temporarily stop the process, disassemble and clean the degassing device before the start of casting work, regularly inspect each part and replace parts, and remove aluminum and fine dust in the gap between sliding parts. In addition, the failure of the expensive vacuum suction device and the clogging of the filter are almost eliminated. Therefore, it is possible to further improve the productivity of the die cast product and reduce the maintenance cost.

The molten metal from the first path (331) and the molten metal from the second path (332) flow along the inner wall and generate a vortex inside the cylindrical intersection (333) as claimed in claim 2. By providing the protrusion (333a) for facilitating the flow, even if the flow of the molten metal becomes faster, a swirl flow is surely generated in the middle of the degassing path (3), and the molten shutoff valve (5) is melted. Since it is possible to delay the entry of foreign matter, it is possible to prevent foreign matter from entering more efficiently.

The merging portion (334) as defined in claim 3, and a cylindrical portion (334a) formed on the upper portion of the cylindrical intersecting portion (333) and a rectangular tubular portion for communicating the cylindrical portion (334a) with the closing valve (5). Since the molten metal reaches the closing valve (5) by being formed of (334b) and (34b), foreign matter can be more reliably prevented from entering the closing valve (5).

The end portion side of the first path (331) and the end portion side of the second path (332) are each bent in two steps to be formed on the fixed block (1) as set forth in claim 4. As a result, the passing distance of the preceding molten metal becomes long, and its arrival can be delayed, so that foreign matter can be prevented from entering the closing valve (5) more efficiently.

It is explanatory drawing which shows embodiment of this invention. It is explanatory drawing which shows the degassing path|route of this embodiment. It is explanatory drawing which shows the gas venting path of other embodiment. It is explanatory drawing which shows the effect|action of the gas vent path of this embodiment. It is explanatory drawing which shows the flow of the pre-melting metal in this embodiment. It is explanatory drawing which shows the state which the molten metal flowed into the degassing path shown in FIG. 3, and was solidified.

Embodiments of the present invention will be described with reference to the drawings. (1) is a fixed block for die casting, and (2) is a movable block. (3) is a degassing path formed between the fixed block (1) and the movable block (2) and communicating with the cavity.

Reference numeral (4) is a pressure receiving valve arranged on the inlet side of the gas vent passage (3), and the pressure receiving valve (4) is arranged in the fixed block (1) and can move up and down. Reference numeral (5) is a closing valve arranged on the outlet side of the gas vent passage (3), and the closing valve (5) is arranged in the fixed block (1) and can move up and down. The structure for closing and opening the gas vent passage (3) by the closing valve (5) is not limited to the above-mentioned structure, and other structures may be used. Further, a part of the outer peripheral surfaces of the pressure receiving valve (4) and the closing valve (5) may be cut to form an air pocket as shown in FIG.

(6) is a swingable opening/closing lever provided for transmitting the operation of the pressure receiving valve (4) to the closing valve (5). Reference numeral (7) is an opening means for lifting the opening/closing lever (6), and a coil spring may be used as the opening means (7). The opening means (7) serves to open the closing valve (5) by pressing the opening/closing lever (6) in the opening direction of the closing valve (5). The opening means (7) is not limited to the coil spring, and an air cylinder or the like may be used. (8) is a closing means for forcibly pressing the opening/closing lever (6) in the closing direction of the closing valve (5) during the initial operation.

FIG. 2 is a diagram showing an embodiment of the gas vent passage, and the gas vent passage (3) will be described in detail based on this figure. The degassing path (3) includes a connection path (31) communicating with the cavity, and a pair of main paths (32) opposed to each other from the upper surface side of the pressure receiving valve (4) to the upper surface side of the closing valve (5). , And a pair of branch paths (33) branching from the main path (32). The role of the branch path (33) is such that the molten metal in the preceding run is slower than the molten metal that passes through the main path (32) and reaches the closing valve (5). The length of the branch route (33) is longer than that of the main route (32) in the direction of the dotted arrow as shown in FIG. 4, and its shape is shown in FIGS. 4 and 6. In this way, it is bent in the horizontal or vertical direction to extend the distance (length). In the branch path (33) at this time, the white part shown in FIG. 6 is formed on the movable block (2) side, and the black dot part is formed on the fixed block (1) side.

Explaining the branch path (33) in more detail, a first path (331) extending from the end of one branch path (33) and a second path (332 extending from the end of the other branch path (33). ), the end of the first path (331) and the end of the second path (332) are eccentrically connected as shown in FIGS. 2 to 4, and a cylindrical intersection (333) for generating a swirl flow therethrough. And a confluence portion (334) extending in the vertical direction of the cylindrical intersection portion (333) and communicating with the closing valve (5). The end portion side of the first path (331) and the end portion side of the second path (332) are each bent in two steps, which are formed in the fixed block (1) as shown in FIG. 4(b). Has been done. The cylindrical intersection (333) is also formed in the fixed block (1), and the molten metal from the first path (331) and the molten metal from the second path (332) intersect inside the cylindrical intersection (333). A substantially boat-shaped protrusion (333a) is provided so as to facilitate the generation of a vortex flow along the inner wall when being struck (see FIG. 5). In addition, in the confluence part (334), a flat cylindrical part (334a) formed at an upper part of the cylindrical intersection part (333) and a flat part for communicating the cylindrical part (334a) with the closing valve (5). There is a square tube part (334b).

Next, how the molten metal flows through the gas venting passage (3) of the present invention will be described with reference to FIG. First, the molten metal flows into the connection path (31), is divided into two directions on the upper surface of the pressure receiving valve (4), passes through the pair of main paths (32), and reaches the upper surface of the closing valve (5) from both sides. The molten metal is solidified (see FIG. 2). At this time, the front-end molten metal having a low temperature toward the closing valve (5) and containing fine dust does not bend the main path (32) as shown by the dotted arrow, but goes straight as shown by the solid arrow and branches off ( 33), as shown in FIG. 4B, the molten metal flows from the movable block (2) side to the fixed block (1) side, and further to the movable block (2) side, and at the cylindrical intersection (333), respectively. The molten metal flows from opposite directions to generate a swirl flow, and they merge and collide with each other to slow down the molten metal flow.

The state in which the molten metal causes a vortex flow inside the cylindrical intersection (333) and flows into the closing valve (5) will be described in more detail with reference to FIG. First, the molten metal flows from the first path (331) toward the cylindrical intersection (333) from the right side as shown by the one-dot chain line, and when the molten metal flows into the cylindrical intersection (333), the lower half of the flow is By contacting the protrusion (333a), the flow of the molten metal flows along the inner wall on the left side (lower side) of the cylindrical intersection (333). On the other hand, when the molten metal flows from the second path (332) toward the cylindrical intersection (333) from the left side as shown by the chain double-dashed line, and the molten metal flows into the cylindrical intersection (333), the lower half of the flow is It flows along the inner wall on the right side (upper side) of the cylindrical intersection (333) by the protrusion (333a) [see FIG. 5(a)]. As a result, the molten metal produces a vortex inside the cylindrical intersection (333). The projections (333a) at this time function like walls for partitioning the molten metal flowing in from opposite directions to each other, and surely facilitate the swirl flow. Further, when the molten metal flows into the inside of the cylindrical intersection (333) one after another from the first path (331) and the second path (332), the molten metal that first generated a swirl and collided is shown in FIG. 5(b). It is lifted as shown by the arrow, and the molten metal further collides with each other in the cylindrical portion (334a) of the confluence portion (334) to form a turbulent state, and the molten metal becomes a square tubular portion (334b) as shown by the white arrow in the figure. ) And flows into the closing valve (5).

As described above, the present invention, the leading metal having a low temperature at the beginning and containing fine dust becomes a turbulent flow after generating a vortex at the cylindrical intersection (333) and is lifted to the upper cylindrical portion (334a), Further, the molten metal is extruded into the rectangular tube portion (334b) and reaches the closing valve (5). During this period, the pressure (kinetic energy) of the molten metal is reduced, the velocity of the molten metal is slowed down, the path of the molten metal is longer than that of the conventional product, and the amount of the molten metal is increased. Of the open/close valves (4) and (5) can be reduced by increasing the temperature of the open/close valves (4) and (5). Even if the casting operation was continued for one week, the closing valve (5) was hardly clogged.

1 Fixed block 2 Movable block 3 Gas venting path
31 Connection route
32 Main route
33 Branch path
331 Route 1
332 Second route
333 Cylindrical intersection
333a protrusion
334 Confluence part
334a Cylindrical part
334b Square tube section 4 Pressure receiving valve 5 Closing valve 6 Opening/closing lever 7 Opening means 8 Closing means

Claims (4)

A pressure-relief valve (4) provided on the inlet side and a closing valve (5) provided on the inlet side, which is provided with a degassing path (3) communicating with the cavity between the fixed block (1) and the movable block (2). An opening/closing lever (6) for transmitting the operation of the pressure receiving valve (4) to the closing valve (5), an opening means (7) for pressing the closing valve (5) in an opening direction, and the opening/closing lever (6) In a die-casting gas venting device comprising at least a closing means (8) for pressing the closing valve (5) in the closing direction by means of a connection path (31) for communicating the gas venting path (3) with the cavity. ), a pair of main paths (32) connecting the pressure receiving valve (4) to the closing valve (5), and a branch path (33) branching from the main path (32), and A first path (331) extending from an end of the one branch path (33), a second path (332) extending from an end of the other branch path (33), and the first path (331) End portion of the second path (332) and the end portion of the second path (332) are eccentrically connected to each other so as to generate a vortex flow, and the closing valve (333) extending in the vertical direction of the cylindrical intersection portion (333). 5) A degassing device for die casting, comprising a confluence part (334) communicating with 5). To facilitate the generation of a swirl along the inner wall when the molten metal from the first path (331) and the molten metal from the second path (332) intersect inside the cylindrical intersection (333). The degassing device for die casting according to claim 1, wherein the projection (333a) is provided in a protruding manner. The confluence part (334) includes a cylindrical part (334a) formed at an upper part of the cylindrical intersection part (333), and a rectangular tube part (334b) for communicating the cylindrical part (334a) with the closing valve (5). The degassing device for die casting according to claim 1, which is formed of The end part side of the said 1st path|route (331) and the end part side of the said 2nd path|route (332) are each bent in two steps, and it was formed in the said fixed block (1). The degassing device for die casting described.