JPH0744369Y2 - Degassing device for die casting - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a degassing device for die casting.

[Conventional technology]

A die-casting degassing device includes, for example, JP-A-63-60.
As described in Japanese Patent No. 059, when the molten metal injected into the cavity in the die-casting mold reaches a vent channel that communicates the cavity with the outside, a vent that closes the vent channel A valve is provided. In the apparatus described in the above publication, a molten metal detection sensor that electrically detects arrival of molten metal is arranged in the vent channel, and an electric signal from the molten metal detection sensor sequentially operates an electric circuit and an air operation circuit. Then, the switching operation of the valve element in the vent valve from the valve open position to the valve close position is performed.

However, in the above case, since the molten metal detection sensor, the electric circuit, and the air circuit are separately required, the configuration becomes complicated, and as a result, the apparatus becomes expensive.

Therefore, for example, the structure can be simplified by adopting a structure in which the valve body of the vent valve is directly switched and operated by the molten metal flow reaching the vent passage. FIG. 11 shows such a configuration example. In the case of the figure, the movable side vent part core 62 with the vent valve 61 assembled and the fixed side vent part core
63 and 63 form a die casting degassing device.

In the central part of the movable side vent part core 62, as shown in FIG.
As shown in FIG. 14, a concave portion 64 that opens on the side of the mating surface with the fixed side vent portion core 63 is formed, and inside this concave portion 64, a substantially circular shape is formed at the end position of the valve body 65. Plate-shaped valve
66 slides in a direction orthogonal to the mating surface. On the end surface of the valve portion 66, an annular protruding surface 67 formed by protruding the peripheral side from the center side is provided.
Further, in the movable side vent portion core 62, from the peripheral side surface of the recess 64, a portion on the peripheral side of the movable side vent portion core 62,
That is, the communication groove 69 extending in the radial direction to the bypass portion 68 is formed along the mating surface. The communicating groove 69 is formed with a depth dimension smaller than that of the recess 64. Further, as shown in FIG. 11, the bottom surface side of the recess 64 communicates with the outside through the exhaust passage 70 and the exhaust gas pipe 71.

On the other hand, the fixed side vent portion core 63 has a structure shown in FIGS.
As shown in the figure, a protrusion 72 is provided in the center, and an inflow groove 73 communicating with the cavity is formed along the mating surface from the outside to the end face of the protrusion 72. Furthermore, from the end surface of the protruding portion 72, to the peripheral side of the fixed side vent portion core 63 is detoured, at the peripheral edge position on the side opposite to the inflow groove 73, that is, at the location corresponding to the bypass location 68. A detour groove 74 is formed along the mating surface.

Each of the cores 62 and 63 having the above-mentioned structure is in close contact with each other, and the 11th
As shown in the figure, when the valve body 65 is located at the position where the annular protruding surface 67 of the valve portion 66 abuts on the intermediate step surface formed on the peripheral side surface of the protruding portion 72, the vent valve 61 is in the open state. And the exhaust gas pipe 71 from the inflow groove 73 as shown by the arrow in the figure.
A vent path leading to is formed. When the molten metal from the cavity flows into this vent path, from the inflow groove 73, the space between the end surface of the protruding portion 72 and the recessed surface on the center side of the valve portion 66,
That is, since the molten metal flow collides with the end face of the valve portion 66 at an angle close to a right angle when it enters the dynamic pressure acting space 75, the dynamic pressure at that time pushes the valve body 65 in the axial direction. Acting as a force to move the valve portion 66 to the bottom surface side of the concave portion 64. As a result, the communication between the communication groove 69 and the exhaust flow path 70 is cut off by the valve portion 66, which causes the vent valve
61 automatically switches to the closed position.

[Problems to be Solved by the Invention] However, in the above-described configuration, the molten metal is used as the exhaust passage 70.
And the switching failure of the valve element 65 is likely to occur. That is, when the molten metal flows into the dynamic pressure acting space 75, in the process of switching movement of the valve body 65 in the valve closing direction,
As shown in the figure, the annular protruding surface 67 on the periphery of the valve portion 66 is a protruding portion.
Away from the intermediate step surface on the peripheral side of 72, and therefore
A state occurs in which the dynamic pressure acting space 75 communicates with the communication groove 69 via the gap between them. At this time, the communication groove 69 is in a transitional state in which the communication groove 69 also communicates with the space on the bottom surface side of the valve portion 66 in the concave portion 64. Therefore, when the flow velocity of the molten metal flow is high, the molten metal flow causes the valve body 65 to Before the movement from the valve opening position to the valve closing position is completed, there is a possibility that the side surface of the concave portion 64 may enter along the short circuit path.
Then, the molten metal that has entered this space also solidifies after that, so that the switching movement of the opening and closing of the valve element 65 does not occur smoothly, resulting in a malfunction.

[Means for Solving the Problems]

In order to solve the above-mentioned problems, the die casting degassing apparatus of the present invention is provided with a concave portion that opens toward the mating surface of the fixed mold and the movable mold, and that slides in this concave portion. Is provided, and extends along the mating surface from the cavity to the inflow groove communicating with the dynamic pressure acting space on the opening end side of the recess, and to the detour position away from the recess from the dynamic pressure acting space. A bypass groove and a communication groove that communicates the bypass portion with the side surface of the recess are respectively formed, and an exhaust flow path that communicates the bottom surface side of the recess to the outside is formed, and further, the valve portion communicates with each other. The dynamic pressure acting space communicates directly with the communication groove without going through the bypass groove until the communication groove is located closer to the bottom surface of the recess than the bottom of the groove and communication between the communication groove and the bottom surface of the recess is cut off. The communication block that shuts off It is characterized in that provided in order to position the Killen through the groove.

[Action]

According to the above configuration, even when the valve body moves from the valve opening position to the valve closing position, the communication cutoff block blocks the communication of the dynamic pressure action space with the communication groove.
The molten metal that has flowed into the dynamic pressure acting space from the inflow groove further reaches the bottom surface side of the recess from the communication groove via the bypass groove. Therefore, the time required to reach the bottom surface side of the recess is longer than in the conventional case, and thereby, the movement of the valve body to the valve closing position can be completed more reliably during this time. As a result, the molten metal does not enter the bottom surface of the recess, and the occurrence of defective opening / closing operations is reduced.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS. 1 to 10.

As shown in FIG. 9 and FIG. 10, the mold in the die-casting device has a fixed core 2 assembled in a fixed holder 1 and a movable core 2 assembled in a movable holder 3. 4 are provided, and a cavity 5 is formed in a central region along the mating surfaces of both cores 3 and 4. A molten metal such as aluminum is poured into the cavity 5 from the lower side in the figure through a pouring port 6. And
A flow path opening / closing part 7 is incorporated in a venting device for die casting according to an embodiment of the present invention, that is, a vent at a lateral position on the upper side with the cavity 5 interposed therebetween. In addition,
As shown in FIG. 10, an ejector box 8 is attached to the rear of the movable holder 3 and the ejector box 8 is provided with a hydraulic cylinder (not shown) or the like in the left or right direction in the drawing. An ejector plate 9 that reciprocates in the direction is arranged. The ejector plate 9 is provided with an ejector pin (not shown) that extends through the movable core 4 and extends to the mating surface, and further extends to the vent passage opening / closing portion 7. A push rod 10 is attached. A push spring 11 made of a compression coil spring is arranged on the outer circumference of the push rod 10, and
The large-diameter portion 12 of the push rod 10 is located near the rear end of the vent passage opening / closing portion 7.

Next, the configuration of the vent passage opening / closing unit 7 will be described.

As shown in FIG. 1, the vent flow path opening / closing section 7 includes a movable side vent section core (movable type) 15 further assembled to the movable side core 4 and the movable side vent branch core 15. And a fixed-side vent portion core (fixed type) 17 assembled to the fixed-side core 2.

As shown in FIGS. 3 and 4, the vent valve 16 includes a substantially cylindrical valve casing 18 and a rod-shaped valve body slidably fitted in an axial center through hole of the valve casing 18. This valve body 19 has a shape having a shaft portion 20 extending in the left-right direction in the drawing and a large-diameter disc-shaped valve portion 21 formed on the left end side of the shaft portion 20. There is. An annular projecting surface 22 is formed on the left end surface of the valve portion 21 so as to project from the center side toward the peripheral edge side.

The valve casing 18 is formed with a recess 25 that opens in the left end surface thereof and is recessed in the axial direction, and the valve portion 21 of the valve body 19 slides in the recess 25 in the axial direction. Therefore, the valve part
When 21 is away from the bottom surface of the recess 25,
A closed space 26 is formed between the bottom surface of 25 and the valve portion 21. The vent valve 16 opens and closes the flow path through the closed space 26. That is, an exhaust flow passage 28 for communicating the closed space 26 with an exhaust gas pipe 27 connected to the outer peripheral side surface of the valve casing 18 is formed from the bottom surface of the recess 25 to the connection portion of the exhaust gas pipe 27. On the other hand, the cylindrical peripheral wall 29 surrounding the concave portion 25 is formed at a depth from the left end face to the midway portion in the axial direction and in the circumferential direction over an angular range of about 90 degrees as shown in FIG. A notched portion 30 that is locally notched is provided. Therefore,
The valve portion 21 is located on the left side of the bottom portion of the cutout portion 30,
As a result, when the bottom side of the cutout 30 communicates with the closed space 26, the space outside the peripheral wall 29 has a cutout.
Exhaust gas pipe 27 through 30, closed space 26, and exhaust flow path 28 in this order
The vent valve 16 is opened. On the other hand, when the valve portion 21 is located closer to the bottom surface side of the recess 25 than the bottom position of the cutout portion 30, the communication between the cutout portion 30 and the closed space 26 is cut off by the valve portion 21, and thus, The vent valve 16 is closed.

The vent valve 16 having the above-described structure is provided with the outer periphery of the peripheral wall 29 fitted into the axial center through hole in the movable side vent part core 15 as shown by the chain double-dashed line in FIGS. 5 and 6. It is attached to the movable side vent part core 15. The depth of the movable side vent part core 15 from the mating surface with the fixed side vent part core 17 is notched in the peripheral wall 29.
A groove 31 that is almost the same as the groove 31 extending in the radial direction from the axial center through hole to the vicinity of the peripheral edge.
As shown in FIG. 5, is formed in a planar shape having a fan-shaped portion on the center side that is continuous with both circumferential end faces of the cutout portion 30. In this way, the notch
By assembling 30 and groove 31 in the circumferential direction,
Due to the notch 30 and the groove 31, the fixed side vent core
A communication groove 33 for communicating a predetermined area on the mating surface with 17 with the peripheral side away from the axis, that is, the bypass portion 32, with the peripheral side surface of the recess 25 is formed. In FIG. 5, 34 and 34 are the insertion holes of the ejector pins, and
Reference numerals 35 and 35 indicate positioning holes, respectively.

On the other hand, the fixed side vent part core 17 has a structure shown in FIGS.
As shown in the figure, a protrusion 37 is provided at the center thereof. On the inclined peripheral side surface of the projecting portion 37, an intermediate step portion with which the annular projecting surface 22 of the valve portion 21 adheres over the entire circumference is provided. Further, in the fixed side vent part core 17, an inflow groove 38 and a bypass groove 39 communicating with the cavity are formed along a mating surface with the movable side vent part core 15. The inflow groove 38 is shaped so as to extend in the direction along the inclined side surface of the protruding portion 37 and open to the end surface of the protruding portion 37 on the center side of the stationary side bent portion core 17. Also,
The detour groove 39 extends from the two peripheral edges on the end face of the protruding portion 37 to the peripheral edge side in the radial direction along the inclined side surfaces of the protruding portion 37 with the center in between, and then the fixed side vent portion core
It has a shape that is curved in a direction opposite to the inflow groove 38 along the peripheral edge of 17 and joins at a position substantially corresponding to the bypass portion 32 in the movable side vent portion core 15.

Further, the fixed side vent part core 17 has substantially the same plane shape as the notch part 30 in the communication groove 33 of the movable side vent part core 15 and the fan-shaped part of the groove 31 connected to this. A communication blocking block 40 that protrudes is formed adjacent to the protruding portion 37 on the side of the confluence point in the detour groove 39.
In addition, the fixed side vent portion core 17 is further provided with positioning pins 41 and 41 which are fitted into the positioning holes 35 and 35 of the movable side vent portion core 15, respectively.

The movable side vent portion core 15, the vent valve 16, and the fixed side vent portion core 17 having the above-described configuration are, as shown in FIG. 1, at the time of mold clamping in the casting molding cycle, the movable side vent portion core 15 and the fixed side. The vent part core 17 and the concentric position of the vent part 17 face each other and are in close contact with each other. In this state, when the valve body 19 is located at the valve opening position, as shown in the drawing, the annular protruding surface 22 of the valve portion 21 is
Contact the intermediate step portion of the protrusion 37 of the stationary side bent portion core 17. At this time, a predetermined space, that is, the dynamic pressure acting space 42 is formed between the end surface of the protrusion 37 and the center-side recessed end surface of the valve portion 21. Further, the communication cutoff block 40 of the fixed side vent part core 17 is fitted into the communication groove 33 of the movable side vent part core 17, and the inner peripheral surface of the communication cutoff block 40 is the peripheral side surface of the valve part 21. On the other hand, the surrounding wall
A region facing the notch portion 30 of 29 is closed to function as a sliding surface for this region. In the valve body 19, an annular groove is formed on the outer peripheral surface of the shaft portion 20 at a midway position, and the ball 45 engaged with the annular groove is
By holding the open position holding spring 46, which is a compression coil spring, from the side by the spring force, the open position holding spring 46 is held at the valve open position as shown in the figure. Further, at the rear end of the shaft portion 20, a rear end member 47 having a slightly larger diameter than the shaft portion 20 is screwed to prevent the valve body 19 from being pulled out forward from the valve casing 18. Further, the spring force of the switching spring 48, which is a compression coil spring, acts on the front end surface of the rear end member 47 as a backward pressing force against the valve body 19.

The spring force of the open position holding spring 46 is the dynamic pressure acting space 42.
When the air is flowing through, the engagement state in the annular groove of the ball 45 is maintained against the sum of the pushing force of the valve body 19 and the spring force of the switching spring 48 due to the dynamic pressure of the air flow. On the other hand, as will be described later, when the flow of the dynamic pressure acting space 42 changes from the air to the molten metal, when the molten metal acts on the dynamic pressure, the balls 45 are disengaged from the annular groove, and the valve body 19 moves rearward. Adjusted to allow for migration. Like this, the ball
When 45 separates from the annular groove, the dynamic pressure of the molten metal and the above switching spring
The spring force of 48 causes the valve element 19 to move to the closed position almost instantaneously.

Next, the operating state of the vent passage opening / closing part 7 in the casting process will be described. In the following description, the left direction in FIG. 1 is the front and the opposite direction is the rear.

First, as shown in FIG. 1, immediately after the mold is clamped, the valve element 19 is located at the valve opening position, and as shown by the arrow in the figure, the vent from the inflow groove 38 to the exhaust gas pipe 27 is vented. A flow path is formed. In this state, the molten metal is poured into the cavity 5. In this process, the air in the cavity is pushed out and discharged to the exhaust gas pipe 27 through the vent valve 16 in the open state. In this case, the exhaust gas pipe 27 is connected to a vacuum pump so that the cavity 5 is forcibly evacuated through the vent valve 16 in the open state, and then the molten metal is injected into the cavity 5. Is also possible.

After the cavity 5 is filled with the molten metal, when the molten metal further reaches the dynamic pressure acting space 42 in the vent valve 16, the flow of the molten metal causes the inflow groove 38 to flow.
Collide with the end face of the valve portion 21 of the valve element 19 at a substantially right angle. As a result, the dynamic pressure of the molten metal flow acts to push the valve body 19 rearward in the axial direction, and as a result, the valve body 19 is switched to the closed valve position shown in FIG. Cause Then, at the time of this switching movement to the valve closing position, even when the annular protruding surface 22 of the end surface of the valve portion 21 is separated from the intermediate step portion in the protruding portion 37 of the fixed side vent portion core 17,
In the above embodiment, the communication groove 33 in the dynamic pressure acting space 42
The side is kept covered with the communication blocking block 40. In this way, the switching movement of the valve element 19 is performed in a state where the short-circuited communication state between the dynamic pressure acting space and the communication groove that has conventionally occurred is blocked by the communication blocking block 40. Therefore, the molten metal collides with the end surface of the valve portion 21 in the dynamic pressure acting space 42 and is inverted, and then from the communication groove 33 via the bypass groove 39 to the closed space.
As a result, the time to reach the closed space 26 becomes longer than in the conventional case. As a result, after the valve body 19 completes its movement to the valve closing position, the molten metal reaches the peripheral side surface of the valve body 19 located at the valve closing position from the communication groove 33,
Invasion into the closed space 26 and the exhaust passage 28, which has occurred conventionally, is prevented.

As described above, after the closing operation of the vent valve 16 is completed, the inside of the cavity 5 is then 800 to 1000 kg / cm ²
The pressurized metal is kept under pressure, and the injected metal is solidified in this state. Thereafter, the mold is opened, and then the ejector plate 9 is moved forward to eject the cast molded product from the surface of the movable core 4 by the ejector pin that moves integrally with the ejector plate 9. Is taken out. At this time, as shown in FIG. 1, the communication groove
The ejector pins 49 also flow into 33 and eject the solidified product. At the same time, as the ejector plate 9 moves forward,
10 forward movements occur. The push rod 10 is configured to be movable relative to the ejector plate 9 in the axial direction.
The ejector plate 9 is assembled by inserting the rear end side in a loosely fitted state into the support hole. Therefore, when the large-diameter portion 12 of the push rod 10 comes into contact with the rear end of the valve body 19, the pushing spring 11 is compressed, and the spring force at this time pushes the valve body 19 to the valve opening position. Be moved.

After that, the ejector plate 9 is retracted to the initial position, and after the mating surface of the mold is cleaned by air blow and the release agent is applied, the mold is clamped and the next Move to molding cycle.

In addition, as shown in FIG. 1, the valve casing 18 has
A compressed air pipe 50 is further connected to the outer peripheral surface thereof. As a result, when a molten metal having a pressure lower than that used in casting is injected into the cavity 5 to preheat the die, an air force is applied to the rear end member 47 of the valve body 19 through the compressed air pipe 50. The valve body 19 can also be placed in the closed position.

[Effect of device]

As described above, in the die casting degassing device of the present invention, when the valve portion that slides in the recess moves from the valve opening position to the valve closing position, the communication between the communication groove and the bottom surface of the recess is the valve. A communication block that blocks the dynamic pressure acting space on the opening end side of the recess from directly communicating with the communication groove without passing through the bypass groove is provided so as to be located in the communication groove until it is disconnected by the portion. It has a structure.

As a result, the molten metal flowing into the dynamic pressure acting space from the inflow groove reaches the bottom surface side of the recess from the communication groove via the bypass groove, and the movement of the valve element to the valve closing position is completed before this. Will be carried out more reliably. As a result, it is possible to prevent the molten metal from entering the bottom surface side of the recessed portion and reduce the occurrence of defective opening / closing operation of the vent valve.

[Brief description of drawings]

1 to 10 show an embodiment of the present invention. FIG. 1 is a cross-sectional view showing the configuration of the vent channel opening / closing section. FIG. 2 is a cross-sectional view of essential parts showing a valve closed state in the vent passage opening / closing part. FIG. 3 is an end view of the vent valve. FIG. 4 is a sectional view of the vent valve. FIG. 5 is a front view of the movable side vent core. FIG. 6 is a sectional view taken along the line VI-VI of FIG. FIG. 7 is a front view of the fixed side bent part core. FIG. 8 is a sectional view taken along the line VIII-VIII in FIG. FIG. 9 is a schematic front view of a die cast mold. FIG. 10 is a schematic side view of the die cast mold. 11 to 16 show a conventional example. FIG. 11 is a cross-sectional view of the main parts of the vent flow passage opening / closing part. FIG. 12 is a cross-sectional view showing a valve closing operation process in the vent passage opening / closing section. FIG. 13 is a front view of the movable side vent core. FIG. 14 is a sectional view taken along the line XIV-XIV in FIG. FIG. 15 is a front view of the fixed side bent part core. FIG. 16 is a sectional view taken along the line XVI-XVI in FIG. 5 is a cavity, 15 is a movable side vent core (movable type),
16 is a vent valve, 17 is a fixed side vent part core (fixed type), 19 is a valve element, 21 is a valve part, 25 is a recessed part, 28 is an exhaust passage,
32 is a detour point, 33 is a communication groove, 38 is an inflow groove, 39 is a detour groove,
40 is a communication blocking block.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Toru Takeshita 3-3 Shinchi, Fuchu-cho, Aki-gun, Hiroshima Mazda Co., Ltd. (56) References JP-A-58-122163 (JP, A) JP-A-63- 60059 (JP, A) JP-A-2-255259 (JP, A) Actually developed 62-109849 (JP, U)

Claims (1)

[Scope of utility model registration request] Claims: 1. A recess is formed facing the mating surface of a fixed mold and a movable mold, and a valve body having a valve portion that slides in the recess is provided. An inflow groove extending from the cavity to the dynamic pressure acting space on the opening end side of the recess, a detour groove extending from the dynamic pressure acting space to a detour location apart from the recess, and the detour location communicating with the side surface of the recess. And a communication groove for communicating the bottom surface side of the recess to the outside, and the valve portion is positioned closer to the bottom surface of the recess than the bottom portion of the communication groove. A communication block that blocks the dynamic pressure working space from directly communicating with the communication groove without going through the bypass groove is located in the communication groove until communication between the groove and the bottom surface of the recess is cut off. It is characterized by being provided Die-cast for the venting system.