CN111069560A

CN111069560A - Flow passage structure

Info

Publication number: CN111069560A
Application number: CN201910992454.4A
Authority: CN
Inventors: 冈田猛; 西原政吾
Original assignee: Honda Motor Co Ltd
Current assignee: Honda Motor Co Ltd
Priority date: 2018-10-22
Filing date: 2019-10-18
Publication date: 2020-04-28
Anticipated expiration: 2039-10-18
Also published as: CN111069560B; JP2020066012A; JP6765401B2

Abstract

The invention provides a flow channel structure. A flow channel (14a) of a flow channel structure (14) is provided with: a 1 st flow path (31) through which a molten metal (M1) flows in a 1 st direction (D1); a 2 nd channel (32) which is connected to the end of the 1 st channel (31) and extends in a 2 nd direction (D2); a 3 rd flow path (33) which is connected to the upstream side of the 1 st flow path (31) and extends in the 3 rd direction (D3); and a 4 th flow path (34) through which the molten metal (M1) flows to a portion connected to the decompression pump (13). A detection unit (36) for detecting the arrival of the molten metal (M1) is provided in the 1 st flow path (31).

Description

Flow passage structure

Technical Field

The invention relates to a flow channel structure.

Background

There is known a die casting method, i.e., die casting, in which a molten metal is pressed into a die at a high speed and a high pressure to mass-produce a cast product with high dimensional accuracy in a short time. Further, a vacuum die casting method is known in which a molten metal is pushed into a cavity of a mold under reduced pressure and in a vacuum state (for example, japanese patent application laid-open No. 2016-.

The technique disclosed in japanese patent application laid-open No. 2016-.

Conventionally, it has been known that gas and air generated from a mold during casting are involved in a molten metal to cause gas defects in a cast product, and various measures such as suppression of gas generation and evacuation are taken. One of the measures is to reduce the pressure in the cavity of the mold during pouring. In order to suppress the gas defect, it is preferable to perform the decompression until the completion of pouring, but if the decompression passage is not cut quickly after the melt is filled, the melt is ejected from the mold and intrudes into the decompression unit or the decompression passage, and therefore, it is necessary to perform the detection of the completion of filling with high accuracy and perform reliable cutting of the decompression passage.

Therefore, as described in japanese patent application laid-open No. 2016 and 131995, a technique has been proposed in which a melt detection sensor is provided at a position facing the flow of the melt in order to improve the melt detection accuracy of the sensor. However, depending on the structure of the runner portion in which the sensor is provided or the amount of gas generated, the sensor portion may retain gas, and even when the melt flows to the portion of the melt detection sensor, the timing at which the melt detection sensor detects the melt may be delayed.

Disclosure of Invention

The present invention has been made in view of the above circumstances, and an object thereof is to provide a flow path structure which can reliably detect a melt and has good exhaust.

A runner structure of the present invention is a runner structure including a melt flow path for connecting a cavity portion of a mold filled with a melt and a pressure reducing device and allowing the melt to flow, the cavity portion being vacuumed by reducing the pressure of the cavity portion via the melt flow path by the pressure reducing device, the runner structure including: a 1 st flow path extending in a 1 st direction, the melt flowing into the melt flow path flowing in the 1 st direction; a 2 nd channel connected to a terminal end of the 1 st channel and extending in a 2 nd direction different from the 1 st direction; a 3 rd flow path which is connected to an upstream side of the 1 st flow path and extends in a 3 rd direction different from the 1 st direction; a detection unit provided in the 1 st flow path and detecting arrival of the melt; and a 4 th channel connected to the 2 nd channel and located downstream of the 3 rd channel.

According to the runner structure of the present invention, since the 2 nd flow path extending in the 2 nd direction different from the 1 st direction is connected to the 1 st flow path end portion of the 1 st flow path in which the melt flowing into the melt flow path flows in the 1 st direction, the gas remaining when the melt flows into the 1 st flow path is pushed by the flowing melt and flows into the 2 nd flow path, and does not remain around the 1 st flow path end portion. This can avoid a situation where the gas stays at the end of the 1 st flow path and the melt cannot reach the detection section provided in the 1 st flow path (a situation where the melt cannot be detected), and can reliably detect the melt. The 2 nd flow path functions as an orifice, and the residual gas flows to the 2 nd flow path, but the flow of the melt is suppressed to a small amount, so that the melt can be filled early around the detection portion. Therefore, a mechanical detection unit that is mechanically pressed by the arrival of the melt can be used, and the cost can be reduced compared to the case of using an electrical sensor. The detection unit may be an electrical sensor as long as it can react when the melt arrives.

In addition, it is preferable that a sectional area of the 2 nd flow path in a direction in which the melt flows is smaller than a sectional area of the 3 rd flow path in the direction in which the melt flows.

According to this configuration, more melt flows through the 3 rd flow path than through the 2 nd flow path. Therefore, a sufficient effective cross-sectional area can be obtained in the process of connecting the decompression device and the cavity, and the reduction of residual gas in the cavity can be facilitated.

Preferably, the 3 rd channel has a curved portion that is curved after extending in the 3 rd direction, the curved portion has a reservoir portion that accumulates the melt flowing through the curved portion, the 3 rd channel is formed such that a width thereof becomes narrower from a portion where the 3 rd channel is connected to the 1 st channel to a portion where the 3 rd channel is connected to the reservoir portion, and the width of the portion where the 3 rd channel is connected to the reservoir portion is formed such that it is smaller than a distance between two opposing portions of an outer surface of the reservoir portion. Further, it is preferable that the 1 st side of the 1 st direction downstream side out of the two sides of the 3 rd flow path constituting the wall surface in the width direction is eccentrically connected to the outer diameter of the reservoir portion in the center direction, and it is further preferable that the 3 rd flow path is formed so that the width is narrowed in the downstream direction and is enlarged in the depth direction orthogonal to the 3 rd direction and the width direction. For example, when the 3 rd direction is an X direction and the width direction is a Y direction, the depth direction is a Z direction.

As a result of extensive studies by the applicant of the present invention, it has been found that when a melt flows in at high pressure and high speed, minute solidified pieces are generated, and the solidified pieces scatter into a cavity and reach a shut valve capable of opening and closing a melt flow passage and a pressure reducing device prior to the melt, the solidified pieces adhere to the shut valve, and malfunction of the shut valve may occur.

According to the above configuration, since the melt can be accumulated in the reservoir portion formed in the curved portion of the 3 rd flow path, the solidified sheet can be also accumulated in the reservoir portion. The solidified pieces stored in the storage portion are mixed into the melt flowing thereafter, so that the solidified pieces can be prevented from adhering to the shutoff valve.

Further, by narrowing the flow direction relative to the width of the 3 rd flow path and expanding the depth direction, a sufficient effective cross-sectional area can be secured in the process of connecting the pressure reducing device and the cavity, contributing to reduction of residual gas in the cavity.

Preferably, the 2 nd flow path is connected to a portion immediately downstream of the 3 rd flow path.

According to this configuration, when the melt flows down to the terminal end of the 1 st channel, the gas flowing down to the 2 nd channel flows directly downstream of the 3 rd channel. Thus, the solidified pieces floating in the gas flowing through the 2 nd flow path are replenished with the melt flowing through the 3 rd flow path, and therefore the solidified pieces do not scatter to the stop valve and adhere to the stop valve.

Drawings

Fig. 1 is a schematic view showing a die casting device having a flow channel structure according to an embodiment of the present invention.

Fig. 2 is a sectional view showing a flow channel structure.

Fig. 3 is a side view showing a flow channel structure.

Fig. 4 is an explanatory diagram showing a state where molten metal flows into the 1 st channel of the runner structure.

FIG. 5 is an explanatory view showing a state in which a molten metal flows through the 1 st channel of the channel structure.

Fig. 6 is an explanatory view showing a state where the molten metal flows to the end of the 1 st channel of the channel structure.

Fig. 7 is an explanatory view showing a state where the molten metal flows to the reservoir portion of the 3 rd flow path of the flow path structure.

Fig. 8 is an explanatory diagram showing a state where the molten metal flows to the 4 th discharge passage of the runner structure.

Detailed Description

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

As shown in fig. 1 to 3, the die casting device 10 includes a supply device 11 for supplying a molten metal M1 (see fig. 4) for casting a metal casting C1, and a casting mold 12 for casting a metal casting C1. The die casting device 10 includes a decompression pump 13 (decompression means) for decompressing and vacuuming the interior of the casting mold 12, a flow path structure 14 for connecting the casting mold 12 and the decompression pump 13, and a control device 15 for collectively controlling the die casting device 10.

The casting mold 12 is a mold for casting a casting C1 of a predetermined metal, and includes a 1 st mold 12a and a 2 nd mold 12 b.

The mold closing is performed by relatively approaching the 2 nd mold 12b to the 1 st mold 12a, and the mold opening is performed by relatively separating the 2 nd mold 12b from the 1 st mold 12 a. In the present embodiment, the 2 nd die 12b is moved leftward in fig. 1 to be closed, and the 2 nd die 12b is moved rightward in fig. 1 to be opened. The 2 nd die 12b is moved by a die moving mechanism (not shown) driven by the control device 15.

The mold cavity 20 of the cast metal C1 is formed by clamping the 1 st mold 12a and the 2 nd mold 12 b. 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, a line connecting the supply device 11 and the casting mold 12, a line connecting the casting mold 12 and the runner structure 14, and a line connecting the runner structure 14 and the decompression pump 13 are used to show the connection.

The 1 st die 12a is provided with a molding recess 21 for forming the cavity 20. The molten metal M1 is supplied from the supply device 11 and is filled into the cavity 20 through a supply passage and a flow path (not shown). The melt M1 of the metal filled in the cavity 20 is sent to the runner structure 14 through the mold passage.

[ flow channel Structure ]

The flow path structure 14 is formed in a hollow shape, and a molten metal M1 conveyed through the cavity 20 and the mold passage flows through a flow path 14a (molten metal flow path) constituting the hollow portion and is discharged from a discharge port 14 b.

The flow path 14a of the flow path structure 14 includes the 1 st flow path 31, and the 1 st flow path 31 extends in the 1 st direction D1 (the vertical direction in fig. 1 and 2) and flows the molten metal M1 flowing from the mold path in the 1 st direction D1. The channel 14a is connected to the terminal end (upper end in fig. 1 and 2) of the 1 st channel 31, and the channel 14a includes the 2 nd channel 32 extending in the 2 nd direction D2 (obliquely downward direction in fig. 1 and 2) different from the 1 st direction D1.

The channel 14a is connected to the upstream side (lower side in fig. 1 and 2) of the 1 st channel 31, and includes a 3 rd channel 33 extending in a 3 rd direction D3 (left-right direction in fig. 1 and 2) different from the 1 st direction D1. The flow path 14a is connected to the 3 rd flow path 33, and the flow path 14a includes the 4 th flow path 34 through which the molten metal M1 flows to a connection portion connected to the vacuum pump 13. The 2 nd to 4 th flow paths 32 to 34 are provided as a pair on the left and right.

A detection section 36 for detecting the arrival of the molten metal M1 is provided in a portion of the 1 st flow path 31 located forward of the end thereof. The detection unit 36 is a mechanical detection unit, and detects the molten metal M1 by coming into contact with the molten metal M1 or being pushed in by the molten metal M1 after the molten metal M1 arrives. When the molten metal M1 disappears by being pressed, the detection unit 36 is automatically returned to the initial position by hand or by the elastic force of an elastic member after the metal cast C1 is taken out. The detection unit 36 is connected to the control device 15, and when the molten metal M1 is detected, the detection unit 36 transmits a detection signal to the control device 15.

The cross-sectional area of the 2 nd flow path 32 in the direction perpendicular to the 2 nd direction D2 (the flow direction of the molten metal M1) is smaller than the cross-sectional area of the 3 rd flow path 33 in the direction perpendicular to the 3 rd direction D3 (the flow direction of the molten metal M1).

In a portion of the 3 rd flow path 33 extending in the 3 rd direction D3, the length in the vertical direction in fig. 3 is inclined so as to become longer from the upstream side to the downstream side.

The 3 rd flow path 33 has a bent portion 33a that extends in the 3 rd direction D3, bends upward, and extends upward. The bent portion 33a is provided with a circular reservoir 33b for storing the molten metal M1 flowing through the bent portion 33 a. The 2 nd channel 32 is connected to the 3 rd channel 33 at a position downstream of the reservoir 33 b.

The 3 rd channel 33 is narrowed from the upstream portion connected to the 1 st channel 31 to the portion connected to the reservoir 33b (toward the downstream side). The 3 rd flow path 33 is formed such that the width of a portion connected to the reservoir 33b is smaller than the diameter of the reservoir 33b (the distance between two opposing portions of the outer surface). With this configuration, it is possible to reliably collect and replenish the scattered solidified pieces P1, which will be described later, in the reservoir 33b while maintaining the flow velocity and flow rate of the molten metal M1.

The 4 th flow path 34 is connected to the downstream end of the 3 rd flow path 33, and flows the molten metal M1 flowing from the 3 rd flow path 33 to the discharge port 14b, and the 4 th flow path 34 includes the 1 st to 4 th discharge paths 41 to 44.

The 1 st discharge passage 41 is provided on the back side (lower side in fig. 3) in fig. 2 of the 3 rd flow passage 33, is connected to the downstream end of the 3 rd flow passage 33, and extends obliquely upward in fig. 2. The 2 nd discharge passage 42 is provided on the front side (upper side in fig. 3) in fig. 2 with respect to the 1 st discharge passage 41, and extends upward in fig. 2 while being connected to the downstream end portion of the 1 st discharge passage 41.

The 3 rd discharge passage 43 is connected to the downstream end of the 2 nd discharge passage 42 and extends in the inward direction in fig. 2. The 1 st to 3 rd discharge passages 41 to 43 are provided as a pair on the left and right in the same manner as the 2 nd to 4 th flow passages 32 to 34.

The 4 th discharge passage 44 is connected to the downstream end portions of the two 3 rd discharge passages 43, and is formed in an arc shape. The 4 th discharge passage 44 is provided with, for example, a circular discharge port 14b, and an on-off valve 48 for opening and closing the discharge port 14 b. The opening/closing valve 48 is driven under control of the control device 15. The opening/closing valve 48 may be provided separately from the flow path structure 14.

[ casting Process ]

When casting the metal casting C1 using the die casting apparatus 10, first, the controller 15 drives the mold moving mechanism to move the 2 nd mold 12b to the left in fig. 1, and closes the mold, thereby forming the cavity 20.

Next, the controller 15 opens the on-off valve 48 to open the discharge port 14b, and then drives the decompression pump 13 to vacuumize the inside of the cavity 20 and the inside of the flow path structure 14.

While maintaining the vacuum state, the controller 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 passage and the flow passage. The cavity 20 and the flow path structure 14 are vacuumed, and the cavity 20 and the flow path structure 14 are connected. Thereby, the molten metal M1 supplied to the cavity 20 is sent to the runner structure 14 through the mold passage.

As shown in fig. 4, the molten metal M1 transferred through the cavity 20 and the mold passage flows into the 1 st flow path 31, and as shown in fig. 5, the molten metal M1 flows in the 1 st direction D1 in the 1 st flow path 31. Fig. 4 to 8 are diagrams simply showing the flow of the molten metal M1.

As shown in FIG. 6, the molten metal M1 flows in the 1 st channel 31 in the 1 st direction D1 and reaches the end of the 1 st channel 31. The molten metal M1 reaching the end of the 1 st flow path 31 flows in the 2 nd direction D2 in the 2 nd flow path 32, and the molten metal M1 flows in the 3 rd direction D3 in the 3 rd flow path 33. In the present embodiment, the 3 rd flow path 33 is formed such that the width (the length in the up-down direction in fig. 2 and 6) becomes narrower toward the flow direction thereof (the 3 rd direction D3), and the depth direction (the up-down direction in fig. 3) of the 3 rd flow path 33 is enlarged. This ensures a sufficient effective cross-sectional area in the process of connecting the decompression pump 13 to the cavity 20, and contributes to reduction of residual gas in the cavity 20.

When the molten metal M1 abuts against the wall surface at the end of the 1 st flow path 31, gas is generated. Since the gas flows in the 2 nd flow path 32 in the 2 nd direction D2, the gas volume can be suppressed from being stored around the terminal end of the 1 st flow path 31. This can avoid the state where the molten metal M1 does not reach the detection section 36 provided in the 1 st flow path 31 (the state where the molten metal M1 cannot be detected), and thus the molten metal M1 can be reliably detected. The 2 nd flow path 32 functions as an orifice and allows passage of the generated gas containing the solidified sheet, but the flow rate can be restricted when a large amount of the molten metal M1 flows down, and the 1 st flow path 31 is filled with the molten metal M1 at an early stage. This enables reliable detection when a mechanical detection system is used.

In addition, the cross-sectional area of the 2 nd flow path 32 in the direction perpendicular to the 2 nd direction D2 (the flow direction of the molten metal M1) is smaller than the cross-sectional area of the 3 rd flow path 33 in the direction perpendicular to the 3 rd direction D3 (the flow direction of the molten metal M1). Therefore, the molten metal M1 flows through the 3 rd flow path 33 more than the 2 nd flow path 32. This can provide a sufficient effective cross-sectional area in the process of connecting the decompression pump 13 to the cavity 20, and can contribute to reduction of residual gas in the cavity 20.

On the other hand, as shown in FIG. 6, the solidified sheet P1 generated when the molten metal M1 flows into the 1 st flow path 31 flows into the 2 nd flow path 32 before the molten metal M1 flows into the bent portion 33a of the 3 rd flow path 33.

As shown in fig. 6, when the molten metal M1 flows in the 1 st flow path 31 in the 1 st direction D1 and reaches the detection portion 36 provided in the near portion of the terminal end of the 1 st flow path 31, the detection portion 36 comes into contact with the molten metal M1 or is pushed by the molten metal M1, and the molten metal M1 is detected. The detection unit 36 sends a detection signal to the control device 15 when detecting the molten metal M1.

When the detection signal is input from the detection unit 36, the control device 15 closes the opening/closing valve 48 to close the discharge port 14b, and then stops the driving of the decompression pump 13.

After the molten metal M1 filled in the cavity 20 is solidified, the 2 nd mold 12b is moved rightward in fig. 1 to open the mold. Then, the metallic cast piece C1 is unloaded from the casting mold 12. Thereby, a metal casting C1 was cast.

In the present embodiment, the opening/closing valve 48 needs a predetermined time T1 when it is changed from the open state to the closed state, and the molten metal M1 flows through the flow path structure 14 during the predetermined time T1.

In the present embodiment, as shown in fig. 7, the solidified sheet P1 that has flowed through the 2 nd flow path 32 and into the bent portion 33a flows into the reservoir 33 b. The molten metal M1 flowing in the 3 rd direction D3 in the 3 rd flow path 33 also flows into the reservoir 33 b. Thus, the solidified piece P1 is mixed into the molten metal M1, and therefore the solidified piece P1 can be prevented from flowing first and adhering to the opening/closing valve 48.

As shown in fig. 8, the molten metal M1 flowing through the 2 nd flow path 32 and the molten metal M1 flowing through the 3 rd flow path 33 are merged and flow through the 1 st to 4 th discharge paths 41 to 44. In the present embodiment, after the predetermined time T1 elapses after the molten metal M1 flows to the 3 rd discharge passage 43, the on-off valve 48 is closed. This can prevent a failure such as breakage from occurring when the open/close valve 48 is closed in a state where the molten metal M1 is discharged from the discharge port 14 b.

In the present embodiment, since the bent portion 33a of the 3 rd flow path 33 and the 1 st discharge path 41 have a step therebetween, the speed at which the molten metal M1 flows from the bent portion 33a of the 3 rd flow path 33 to the 1 st discharge path 41 is slower than in the case where there is no step. Similarly, the 1 st discharge passage 41 and the 2 nd discharge passage 42 have a step difference. Thus, the speed of the molten metal M1 flowing from the bent portion 33a to the 4 th discharge passage 44 is slower than that in the case where there is no step difference. Therefore, the predetermined time T1 can be extended, and an inexpensive on-off valve that takes a long time to close from an open state can be used.

In the present embodiment, since the 2 nd discharge path 42 extends to the upper side in fig. 2 than the 3 rd discharge path 43, the molten metal M1 of the metal flowing in from the 1 st discharge path 41 turns back while flowing to the upper end in fig. 2 of the 2 nd discharge path 42, and then flows into the 3 rd discharge path 43 (see fig. 8). Accordingly, the time for the flow from the 2 nd discharge path 42 to the 3 rd discharge path 43 can be extended as compared with the case where the above-described folding back is not performed, and the above-described predetermined time T1 can be extended.

While the preferred embodiments of the present invention have been described above, it will be readily understood by those skilled in the art that the present invention is not limited to such embodiments, and can be modified as appropriate without departing from the spirit of the present invention.

For example, the shape of the flow path structure 14 can be changed as appropriate, and for example, the shape of the reservoir 33b and the 4 th discharge passage 44 may be rectangular.

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

In addition, not all the components shown in the above embodiments are essential, and can be appropriately selected without departing from the gist of the present invention.

Claims

1. A runner structure comprising a molten metal flow path for connecting a cavity section of a mold to be filled with molten metal and a pressure reducing device and allowing the molten metal to flow, wherein the cavity section is vacuumed by the pressure reducing device by reducing the pressure of the cavity section via the molten metal flow path,

characterized in that the melt flow path is internally provided with:

a 1 st flow path extending in a 1 st direction, the melt flowing into the melt flow path flowing in the 1 st direction;

a 2 nd channel connected to a terminal end of the 1 st channel and extending in a 2 nd direction different from the 1 st direction;

a 3 rd flow path which is connected to an upstream side of the 1 st flow path and extends in a 3 rd direction different from the 1 st direction;

a detection unit provided in the 1 st flow path and detecting arrival of the melt; and the number of the first and second groups,

and a 4 th channel connected to the 2 nd channel and located downstream of the 3 rd channel.

2. The flow channel structure according to claim 1,

the cross-sectional area of the 2 nd flow path in the direction in which the melt flows is smaller than the cross-sectional area of the 3 rd flow path in the direction in which the melt flows.

3. The flow channel structure according to claim 1 or 2,

the 3 rd flow path has a bent portion bent after extending in the 3 rd direction,

a reservoir portion that accumulates the melt flowing through the bending portion is formed in the bending portion,

the 3 rd flow path is formed such that the width thereof becomes narrower from a portion where the 3 rd flow path is connected to the 1 st flow path to a portion where the 3 rd flow path is connected to the reservoir, and the width of the portion where the 3 rd flow path is connected to the reservoir is formed smaller than the distance between the two opposing portions of the outer surface of the reservoir.

4. The flow channel structure according to claim 1 or 2,

the 2 nd flow path is connected to a portion of the 3 rd flow path immediately downstream.