JP6765401B2 - Runner structure - Google Patents

Description

The present invention relates to a runner structure.

A mold casting method called die casting, which is a casting method for mass-producing castings with high dimensional accuracy in a short time by press-fitting molten metal into a mold at high speed and high pressure, is known. Further, a vacuum die casting method is also known in which the molten metal is press-fitted in a state where the cavity portion of the mold is depressurized and evacuated (see, for example, Patent Document 1).

In Patent Document 1, a gas vent path for connecting the cavity and the decompression means and a decompression valve for opening and closing the gas vent path are provided, and a position opposed to the flow of molten metal between the cavity of the gas vent path and the decompression valve. Is equipped with a molten metal detection sensor.

Japanese Unexamined Patent Publication No. 2016-131995

It has long been known that gas and air generated from the mold are caught in the molten metal during pouring, causing gas defects in the casting, and various measures have been taken such as suppressing gas generation and degassing. There is. One of the countermeasures is to reduce the pressure inside the mold cavity when pouring hot water. It is desirable to reduce the pressure until the pouring is completed in order to suppress gas defects, but if the decompression path is not shut off immediately after filling the molten metal, the molten metal will eject from the mold and the molten metal will invade the decompression means and the decompression path. Therefore, it is necessary to perform highly accurate detection of filling completion and reliable blocking of the decompression path. Therefore, as in Patent Document 1, a technique has been proposed in which a molten metal detection sensor is provided at a position opposed to the flow of the molten metal to improve the accuracy of the molten metal detection of the sensor. However, depending on the structure of the runner section where the sensor is installed and the amount of gas generated, gas stays in the sensor section, and even if the molten metal flows to the molten metal detection sensor, the timing of detecting the molten metal with the molten metal detection sensor will be delayed. Sometimes.

The present invention has been made in view of such circumstances, and an object of the present invention is to provide a runner structure capable of reliably detecting molten metal and having good gas release.

The runner structure of the present invention is provided with a molten metal flow path through which the molten metal flows by connecting a cavity portion of a mold filled with the molten metal and a decompression means, and the cavity portion is depressurized through the molten metal flow path by the decompression means. A first flow path that extends in the first direction and allows the molten metal that has flowed into the molten metal flow path to flow in the first direction, and the first flow path, which has a runner structure for evacuating. A second flow path connected to the end of the first flow path and extending in a second direction different from the first direction, and a third flow path connected to the upstream side of the first flow path and different from the first direction. a third flow path extending in the direction, disposed within the first flow path, and a detector for detecting the arrival of the molten metal, a fourth flow of the second flow path downstream of the third flow passage is connected A passage is provided, and the third flow path has a bent portion that is bent after extending in the third direction, and the bent portion has a storage portion for storing the molten metal that has flowed into the bent portion. The width of the third flow path is narrowed from the portion connected to the first flow path toward the portion connected to the storage portion, and the width of the portion connected to the storage portion is the width of the portion. It is characterized in that it is formed so as to be smaller than the distance between two opposing portions on the outer surface of the storage portion .

According to the runner structure of the present invention, a second flow path extending in a second direction different from the first direction is connected to the end of the first flow path through which the molten metal flowing into the molten metal flow path flows in the first direction. Therefore, the gas remaining when the molten metal flows into the terminal portion of the first flow path is pushed by the flow of the molten metal and flows down to the second flow path, and may be accumulated around the terminal portion of the first flow path. Absent. As a result, it is possible to prevent the gas from staying at the end of the first flow path and preventing the molten metal from reaching the detection unit provided in the first flow path (a state in which the molten metal cannot be detected). It is possible and the molten metal can be detected reliably. Further, the second flow path serves as an orifice, and the residual gas flows to the second flow path, but the flow of the molten metal is suppressed to a small amount, so that the molten metal fills the periphery of the detection unit at an early stage. Therefore, it is possible to use a mechanical detection unit that is mechanically pressed by the arrival of the molten metal, and it is possible to reduce the cost as compared with the case of using an electric sensor. The detection unit may be an electric sensor as long as it reacts when the molten metal arrives.

Further, it is preferable that the second flow path has a smaller cross-sectional area in the direction in which the molten metal flows than the third flow path.

According to this configuration, more molten metal flows in the third flow path than in the second flow path. As a result, a sufficient effective cross-sectional area can be obtained in the process of connecting the decompression means to the cavity, which can contribute to the reduction of the residual gas in the cavity.

As a result of diligent examination by the applicant, when the molten metal flows in at high pressure and high speed, minute solidified pieces are generated and scattered in the cavity, and the solidified pieces are used in the molten metal flow path and the depressurizing means before the molten metal. It was found that when the openable shutoff valve that shuts off the connection is reached, the coagulated pieces may adhere to the shutoff valve and cause the shutoff valve to malfunction.

According to the above configuration, the molten metal can be stored in the storage portion formed at the bent portion of the third flow path, so that the coagulated pieces can also be stored in the storage portion. Since the coagulated pieces accumulated in this storage portion are mixed in the molten metal that flows later, it is possible to prevent the coagulated pieces from adhering to the shutoff valve.

Further, while the width becomes narrower in the flow direction of the third flow path, by expanding the depth direction, a sufficient effective cross-sectional area is secured in the process of connecting from the decompression means to the cavity, and the residual gas in the cavity is retained. Can contribute to the decrease.

Further, it is preferable that the second flow path is connected to a portion immediately downstream of the third flow path.

According to this configuration, when the molten metal flows down to the end of the first flow path, the gas that flows down into the second flow path can flow to the immediate downstream side of the third flow path. As a result, the solidified pieces suspended in the gas flowing through the second flow path are captured by the molten metal flowing through the third flow path, so that the solidified pieces do not scatter to the shutoff valve and adhere to the shutoff valve. ..

It is the schematic which shows the die-casting apparatus which has the runner structure of embodiment of this invention. It is sectional drawing which shows the runner structure. It is a side view which shows the runner structure. It is explanatory drawing which shows the state which the molten metal flowed into the 1st flow path of a runner structure. It is explanatory drawing which shows the state which the molten metal flowed through the 1st flow path of a runner structure. It is explanatory drawing which shows the state which the molten metal flowed to the end part of the 1st flow path of a runner structure. It is explanatory drawing which shows the state which the molten metal flowed to the storage part of the 3rd flow path of a runner structure. It is explanatory drawing which shows the state which the molten metal flowed to the 4th discharge passage of a runner structure.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

As shown in FIGS. 1 to 3, the die casting device 10 includes a supply device 11 for supplying a molten metal M1 (see FIG. 4) for casting the metal casting C1 and a casting die for casting the metal casting C1. The mold 12, the decompression pump 13 that decompresses the inside of the casting die 12 to vacuum, the runner structure 14 that connects the casting die 12 and the decompression pump 13, and the control device that comprehensively controls the die casting device 10. 15 is provided.

The casting die 12 is for casting a predetermined metal casting C1, and includes a first mold 12a and a second mold 12b.

Molding is performed by bringing the second type 12b relatively close to the first type 12a, and mold opening is performed by relatively separating the second type 12b from the first type 12a. In the present embodiment, the mold is clamped by moving the second mold 12b to the left in FIG. 1, and the mold is opened by moving the second mold 12b to the right in FIG. The second type 12b is moved by a type moving mechanism (not shown) driven by the control device 15.

By performing the mold clamping with the first mold 12a and the second mold 12b, the cavity 20 in which the metal casting C1 is cast is formed. The cavity 20 is connected to the runner structure 14 via a mold passage (not shown) provided in the casting mold 12. In FIG. 1, the line connecting the supply device 11 and the casting die 12, the line connecting the casting die 12 and the runner structure 14, and the line connecting the runner structure 14 and the pressure reducing pump 13 are connected. It is a line to show that there is.

The first type 12a is provided with a forming recess 21 for forming the cavity 20. The molten metal M1 is supplied from the supply device 11 and fills the cavity 20 through a supply path and a runner (not shown). The molten metal M1 filled in the cavity 20 is sent to the runner structure 14 through the mold passage.

[Runner structure]
The runner structure 14 is formed in a hollow shape, and the molten metal M1 sent through the cavity 20 and the mold passage flows through the flow path 14a which is the hollow portion and is discharged from the discharge port 14b.

The flow path 14a of the runner structure 14 extends in the first direction D1 (vertical direction in FIGS. 1 and 2), and the first flow path 31 for flowing the molten metal M1 flowing from the mold passage into the first direction D1. And is connected to the end portion (upper end portion in FIGS. 1 and 2) of the first flow path 31 and extends in the second direction D2 (diagonally downward direction in FIGS. 1 and 2) different from the first direction D1. It is provided with two flow paths 32.

The flow path 14a is connected to the upstream side (lower side in FIGS. 1 and 2) of the first flow path 31 and extends in a third direction D3 (horizontal direction in FIGS. 1 and 2) different from the first direction D1. A third flow path 33 and a fourth flow path 34 connected to the third flow path 33 and flowing the molten metal M1 to the connecting portion with the decompression pump 13 are provided. The second to fourth flow paths 32 to 34 are provided in pairs on the left and right.

A detection unit 36 for detecting the arrival of the molten metal M1 is provided in front of the terminal portion of the first flow path 31. The detection unit 36 is a mechanical detection unit, and when the molten metal M1 arrives, the molten metal M1 is detected by coming into contact with or being pushed into the molten metal M1. When the pressing by the molten metal M1 is removed, the detection unit 36 is automatically returned to the initial position after taking out the metal casting C1 manually or by using the elastic force of the elastic member. The detection unit 36 is connected to the control device 15, and when it detects the molten metal M1, it sends a detection signal to the control device 15.

The cross-sectional area of the second flow path 32 in the direction orthogonal to the second direction D2 (direction in which the molten metal M1 flows) is orthogonal to the third direction D3 (direction in which the molten metal M1 flows) of the third flow path 33. It is smaller than the cross-sectional area in the direction.

The third flow path 33 is inclined so that the length in the vertical direction in FIG. 3 becomes longer from the upstream side to the downstream side in the portion extending in the third direction D3.

The third flow path 33 has a bent portion 33a that extends upward in the third direction D3 and then bends upward. The bent portion 33a is formed with, for example, a circular storage portion 33b for storing the molten metal M1 that has flowed through the bent portion 33a. The second flow path 32 is connected to the downstream side of the storage portion 33b of the third flow path 33.

The width of the third flow path 33 narrows from the upstream portion connected to the first flow path 31 toward the portion connected to the storage portion 33b (toward the downstream side). The third flow path 33 is formed so that the width of the portion connected to the storage portion 33b is smaller than the diameter of the storage portion 33b (the distance between the two opposing portions on the outer surface). With this configuration, while maintaining the flow velocity and the flow rate of the molten metal M1, the scattered solidified pieces P1 described in detail can be reliably collected and supplemented in the storage portion 33b.

The fourth flow path 34 is connected to the downstream end of the third flow path 33 and allows the molten metal M1 flowing from the third flow path 33 to flow to the discharge port 14b, and the first to fourth discharges. The roads 41 to 44 are provided.

The first discharge passage 41 is provided on the back side (lower side in FIG. 3) in FIG. 2 from the third flow path 33, is connected to the downstream end of the third flow path 33, and extends diagonally upward in FIG. .. The second discharge passage 42 is provided on the front side (upper in FIG. 3) in FIG. 2 with respect to the first discharge passage 41, is connected to the downstream end of the first discharge passage 41, and extends upward in FIG.

The third discharge passage 43 is connected to the downstream end of the second discharge passage 43 and extends inward in FIG. The first to third discharge passages 41 to 43 are provided in pairs on the left and right, similarly to the second to fourth flow paths 32 to 34.

The fourth discharge passage 44 is connected to each downstream end of the two third discharge passages 43 and is formed in an arc shape. For example, a circular discharge port 14b is formed in the fourth discharge path 44, and an on-off valve 48 for opening and closing the discharge port 14b is provided. The drive of the on-off valve 48 is controlled by the control device 15. The on-off valve 48 may be provided separately from the runner structure 14.

[Casting process]
When casting the metal casting C1 by the die casting device 10, first, the control device 15 drives the mold moving mechanism to move the second mold 12b to the left side in FIG. 1 to perform mold clamping to form the cavity 20. To do.

Next, the control device 15 opens the on-off valve 48 to open the discharge port 14b, and then drives the pressure reducing pump 13 to evacuate the inside of the cavity 20 and the inside of the runner structure 14.

While maintaining the vacuuming, the control device 15 drives the supply device 11 to supply the molten metal M1 and fills the cavity 20 with the molten metal M1 through the supply path and the runner. Since the cavity 20 and the runner structure 14 are evacuated and the cavity 20 is connected to the runner structure 14, the molten metal M1 supplied to the cavity 20 passes through the mold passage to the runner structure 14. Sent.

As shown in FIG. 4, the molten metal M1 sent through the cavity 20 and the mold passage flows into the first flow path 31, and as shown in FIG. 5, the molten metal M1 is the first. It flows in the first direction D1 in the flow path 31. It should be noted that FIGS. 4 to 8 are diagrams that simply show the flow of the molten metal M1.

As shown in FIG. 6, when the molten metal M1 flows in the first flow path 31 in the first direction D1 and reaches the end of the first flow path 31, the molten metal M1 moves into the second flow path 32. It flows in the second direction D2, and further flows in the third flow path 33 in the third direction D3. In the present embodiment, the width (length in the vertical direction in FIGS. 2 and 6) of the third flow path 33 becomes narrower in the flow direction (third direction D3), whereas the width (length in the vertical direction in FIGS. 2 and 6) becomes narrower in the depth direction (FIG. 3). (Up and down direction) is formed so as to expand. As a result, a sufficient effective cross-sectional area can be secured in the process of connecting the pressure reducing pump 13 to the cavity 20, and the residual gas in the cavity 20 can be reduced.

When the molten metal M1 comes into contact with the wall surface at the end of the first flow path 31, gas is generated. Since this gas flows in the second flow path 32 in the second direction D2, it is possible to prevent the gas from accumulating around the terminal portion of the first flow path 31. As a result, it is possible to prevent the molten metal M1 from reaching the detection unit 36 provided in the first flow path 31 due to the gas (a state in which the molten metal M1 cannot be detected). The molten metal M1 can be reliably detected. Further, the second flow path 32 serves as an orifice, and the generated gas containing the solidified piece passes through, but when a large amount of molten metal M1 flows down, the flow rate is limited, and the first flow path 31 is the metal at an early stage. Fill with molten metal M1. As a result, when a mechanical detection method is used, it can be reliably detected.

Further, the cross-sectional area in the direction orthogonal to the second direction D2 (flow direction of the molten metal M1) of the second flow path 32 is in the third direction D3 (direction of flow of the molten metal M1) of the third flow path 33. It is smaller than the cross-sectional area in the orthogonal direction. Therefore, the molten metal M1 flows more in the third flow path 33 than in the second flow path 32. As a result, a sufficient effective cross-sectional area can be obtained in the process of connecting the pressure reducing pump 13 to the cavity 20, which can contribute to the reduction of the residual gas in the cavity 20.

On the other hand, as shown in FIG. 6, the solidified piece P1 generated when the molten metal M1 flows into the first flow path 31 flows through the second flow path 32 before the molten metal M1 and is the third. It flows into the bent portion 33a of the flow path 33.

As shown in FIG. 6, when the molten metal M1 flows in the first flow path 31 in the first direction D1 and reaches the detection unit 36 provided in the front portion of the terminal portion of the first flow path 31, it is detected. The unit 36 is brought into contact with or pushed into the molten metal M1 to detect the molten metal M1. When the detection unit 36 detects the molten metal M1, it sends a detection signal to the control device 15.

When the detection signal is input from the detection unit 36, the control device 15 closes the on-off valve 48, closes the discharge port 14b, and then stops the drive of the pressure reducing pump 13.

After the molten metal M1 filled in the cavity 20 is solidified, the second mold 12b is moved to the right in FIG. 1 to open the mold. Then, the metal casting C1 is removed from the casting mold 12. As a result, the metal casting C1 is cast.

In the present embodiment, it takes a predetermined time T1 from the open / closed state to the closed state of the on-off valve 48, and during this predetermined time T1, the molten metal M1 flows in the runner structure 14.

In the present embodiment, as shown in FIG. 7, the solidified piece P1 that has flowed through the second flow path 32 and has flowed into the bent portion 33a flows into the storage portion 33b. The molten metal M1 flowing in the third direction D3 also flows into the storage portion 33b in the third flow path 33. As a result, the solidified piece P1 is mixed in the molten metal M1, so that the solidified piece P1 can be prevented from flowing in advance and adhering to the on-off valve 48.

As shown in FIG. 8, the molten metal M1 flowing through the second flow path 32 and the molten metal M1 flowing through the third flow path 33 merge and flow through the first to fourth discharge passages 41 to 44. In the present embodiment, when the molten metal M1 flows to the third discharge passage 43, the predetermined time T1 elapses and the on-off valve 48 is closed. As a result, it is possible to prevent a failure such as breakage that occurs when the on-off valve 48 is closed while the molten metal M1 is discharged from the discharge port 14b.

In the present embodiment, since the bent portion 33a of the third flow path 33 and the first discharge path 41 have a step, the molten metal M1 has a bent portion 33a of the third flow path 33 as compared with the one having no step. The speed when flowing from to the first discharge passage 41 becomes slow. Similarly, there is a step between the first discharge path 41 and the second discharge path 42. As a result, the speed at which the molten metal M1 flows from the bent portion 33a to the fourth discharge passage 44 becomes slower than that without a step. Therefore, the above-mentioned predetermined time T1 can be lengthened, and an on-off valve that takes a long time from the open state to the closed state but is inexpensive can be used.

Further, in the present embodiment, since the second discharge passage 42 extends to the upper side in FIG. 2 with respect to the third discharge passage 43, the molten metal M1 flowing in from the first discharge passage 41 is the second discharge passage 42. After flowing to the upper end in FIG. 2 and turning back, it flows into the third discharge passage 43 (see FIG. 8). As a result, the time from the second discharge passage 42 to the third discharge passage 43 can be lengthened, and the predetermined time T1 can be lengthened, as compared with the case where there is no folding back.

The present invention has been described above with respect to preferred embodiments thereof, but as can be easily understood by those skilled in the art, the present invention is not limited to such embodiments and deviates from the gist of the present invention. It can be changed as appropriate as long as it does not.

For example, the shape of the runner structure 14 can be changed as appropriate. For example, the shape of the storage portion 33b and the fourth discharge passage 44 may be rectangular.

In the above embodiment, the mechanical detection unit 36 is used, but any electric sensor may be used as long as it detects the arrival of the molten metal M1.

In addition, not all of the constituent elements shown in the above embodiments are indispensable, and they can be appropriately selected as long as they do not deviate from the gist of the present invention.

10 ... Die casting device, 11 ... Supply device, 12 ... Casting die, 13 ... Decompression pump (decompression means), 14 ... Runner structure, 14a ... Flow path (molten metal flow path), 14b ... Discharge port, 15 ... Control device, 20 ... Cavity, 31.34 ... First to fourth flow paths, 33a ... Bending part, 33b ... Storage part, 36 ... Detection part, 41 to 44 ... First to fourth discharge passages, 48 ... Open / close valve, D1 to D3 ... 1st to 3rd directions, M1 ... molten metal, P1 ... solidified piece

Claims (3)

With a runner structure in which the cavity of the mold filled with the molten metal and the decompression means are connected, the molten metal flow path through which the molten metal flows is provided, and the cavity is depressurized and evacuated through the molten metal flow path by the decompression means. There,
In the molten metal flow path,
A first flow path extending in the first direction and flowing the molten metal flowing into the molten metal flow path in the first direction,
A second flow path that is connected to the end of the first flow path and extends in a second direction different from the first direction.
A third flow path connected to the upstream side of the first flow path and extending in a third direction different from the first direction,
Provided within the first flow path, and a detector for detecting the arrival of the molten metal,
A fourth flow path to which the second flow path is connected downstream of the third flow path,
Is provided,
The third flow path has a bent portion that is bent after extending in the third direction.
A storage portion for storing the molten metal flowing through the bent portion is formed in the bent portion.
The width of the third flow path becomes narrower from the portion connected to the first flow path toward the portion connected to the storage portion, and the width of the portion connected to the storage portion is the width of the storage portion. A runner structure characterized in that it is formed so as to be smaller than the distance between two opposing portions on the outer surface . In the runner structure according to claim 1,
The second flow path has a runner structure having a smaller cross-sectional area in a direction orthogonal to the direction in which the molten metal flows than the third flow path. In the runner structure according to claim 1 or 2.
The runner structure is characterized in that the second flow path is connected to a portion immediately downstream of the third flow path.