JP7172517B2 - Hollow die-cast product, die-cast method - Google Patents

Description

The present invention relates to a hollow die casting article and a die casting method used to obtain this hollow die casting article.

2. Description of the Related Art Conventionally, die-cast subframes are known that are used as strength members for supporting vehicle parts when the vehicle parts are attached to a vehicle body. This type of die-cast sub-frame includes a frame-shaped portion having an opening in the center and a substantially rectangular outer shape, and arm portions extending outward from each of the four corners of the frame-shaped portion. By providing it, the overall shape is configured to have a substantially parallel grid shape. As a prior art document disclosing such a conventional die-cast subframe, for example, Patent Document 1 below exists.

Patent Document 1 below discloses a die-cast sub-frame (see FIG. 4 of Patent Document 1) cast by a die-casting machine capable of arranging a casting port at the position of an opening formed in the center, and a sub-frame formed in the center. A die-cast sub-frame (see FIG. 5 of Patent Document 1) cast by a die-casting machine in which a casting port is arranged outside the opening and below a substantially rectangular frame-shaped portion; is disclosed.

In the die-cast subframe described in Patent Literature 1 below, a plurality of arm mounting portions are installed on a parallel cross-shaped subframe, and the pouring port faces the plurality of arm mounting portions. By arranging the runner and performing die casting, the casting near the outlet of the runner becomes denser and stronger than other parts, and the effect of being able to sufficiently increase the strength of the arm mounting part can be exhibited. It is said that

JP-A-2002-137758

However, in the case of the die-cast subframe of the type shown in FIG. 5 of Patent Document 1 cited above, the casting port is located at the bottom, and the runner leading to the cavity is connected only to the bottom of the die-cast subframe. Therefore, when performing die casting, there is a problem that it is difficult to manufacture a die cast product having a stable quality due to poor circulation of molten metal.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems existing in the prior art, and an object of the present invention is to manufacture a hollow die cast product using a die casting apparatus in which a casting hole is arranged at a position below a cavity. To provide a hollow die-cast article having a feature that a product of stable quality can be obtained even in the case of die-casting, and a new die-casting method used for obtaining the hollow die-cast article.

The present invention will be described below. In order to facilitate understanding of the present invention, the reference numbers of the attached drawings are added in parentheses, but the present invention is not limited to the illustrated forms.

A hollow die cast product (50) according to the present invention is a hollow die cast product (50) having an opening (51) in the center and a frame-shaped part (52) surrounding the opening (51), wherein the hollow A die-casting apparatus for die-casting a die-cast product (50) is formed in a die-casting mold (1) having a fixed mold (10) and a movable mold (20) that can advance and retreat with respect to the fixed mold (10). The casting port (1b) for filling the molten metal (2) is arranged below the cavity (1a), and the casting port (1b) is above the casting port (1b). A main runner (62) is provided toward the main runner (62), and is introduced so that the tip of the main runner (62) is arranged at the formation position of the opening (51), and a plurality of The frame-shaped portion (52) in the cavity (1a) formed in the die-casting mold (1), wherein a runner is formed to be connected to the inner peripheral surface of the frame-shaped portion (52). A lower core (25) is provided during die casting at a portion where the lower part of the frame-shaped part (52) is formed. A contact trace (52a) with the lower core (25) is formed in the lower portion of the frame-shaped portion (52) .

Further, in the hollow die-cast product (50) according to the present invention, the main runners (62) can be arranged in a pair and laterally.

Furthermore, in the hollow die cast product (50) according to the present invention, a pair of sub-runners (65, 65) are provided in the lateral direction in the casting port (1b), and the pair of sub-runners (65, 65) , 65) Runners connected to the vicinity of the left and right ends of the lower portion of the frame-shaped portion (52) are formed at the respective tips, so that the vicinity of the left and right ends of the lower portion of the frame-shaped portion (52) A runner mark may be formed.

Further, the hollow die cast product (50) according to the present invention includes the frame-shaped portion (52) having the opening (51) in the center and having a substantially rectangular outer shape, and the frame-shaped portion (52). Arm portions (53) extending outward from each of the four corners are provided, and the overall shape has a substantially parallel grid shape, and a strength member that supports the vehicle part when the vehicle part is attached to the vehicle body. It can be a die-cast subframe (50) used as a

In the die casting method according to the present invention, the hollow die casting product (50) described above can be obtained by die casting using the die casting apparatus.

According to the present invention, even when a hollow die-cast product is die-cast using a die-casting apparatus in which the casting port is arranged at a position below the cavity, it is possible to obtain a product of stable quality. It is possible to provide a hollow die-cast article with a hollow die-cast article and a new die-casting method used to obtain the hollow die-cast article.

1 is a cross-sectional view showing an example of the overall configuration of a die-casting apparatus having a general die-casting mold, and particularly showing a state before being filled with molten metal; FIG. 1 is a cross-sectional view showing an example of the overall configuration of a die-casting apparatus equipped with a general die-casting mold, and particularly showing a state after being filled with molten metal; FIG. 1 is a front view of a die-cast subframe according to this embodiment; FIG. It is a rear view of the die-cast sub-frame according to the present embodiment. 1 is an external perspective view showing the overall configuration of a die-cast sub-frame according to this embodiment; FIG. FIG. 4 is a diagram showing the form of the die-cast sub-frame according to the present embodiment immediately after production, which is produced by a general die-casting machine, and particularly shows a front view. FIG. 4 is a diagram showing the form of the die-cast subframe according to the present embodiment immediately after production, which is produced by a general die-casting machine, and particularly shows a rear view. FIG. 7 is a diagram for explaining the positional relationship between the die-cast subframe shown in FIG. 6 and a lower core used when performing the die-casting method; FIG. 8 is a diagram for explaining the positional relationship between the die-cast subframe shown in FIG. 7 and a lower core used when performing the die-casting method; FIG. 4 is a perspective view showing a state in which the die-cast sub-frame and the lower core according to the present embodiment are arranged in a fixed mold;

Preferred embodiments for carrying out the present invention will be described below with reference to the drawings. In addition, the following embodiments do not limit the invention according to each claim, and not all combinations of features described in the embodiments are essential for the solution of the invention. .

Before describing the hollow die-cast product according to the present embodiment and the die-casting method used to obtain the hollow die-cast product, first, based on FIGS. An explanation will be given of the overall configuration of a typical die casting machine. Here, FIGS. 1 and 2 are cross-sectional views showing an example of the overall configuration of a die casting apparatus equipped with a general die casting mold 1. In particular, FIG. 1 shows a state before filling with molten metal. FIG. 2 shows the state after filling with molten metal. As shown in FIGS. 1 and 2, a die casting mold 1 is provided as a main component of a die casting apparatus for performing die casting.

The illustrated general die casting mold 1 has a fixed die 10 with a fixed die 12 and a fixed holder 11 and a movable die 20 with a movable die 22 and a movable holder 21 . A cavity 1 a is defined by the fixed die 12 and the movable die 22 . Further, the die casting mold 1 is provided with a sleeve 30 . The sleeve 30 communicates with the cavity 1a via the biscuit forming portion 1b, the runner forming portion 1c, and the gate forming portion 1d. A plunger tip 31 is provided in the sleeve 30 . The plunger tip 31 can move forward and backward within the sleeve 30 . Further, a flow diverter 40 is provided at the position of the biscuit forming portion 1b that faces the plunger tip 31 in the advancing direction. When the plunger tip 31 advances in the sleeve 30 and presses the molten metal 2, the molten metal 2 is filled into the cavity 1a through the biscuit forming portion 1b, the runner forming portion 1c, and the gate forming portion 1d, which are casting ports. . By advancing the plunger tip 31 from the state shown in FIG. 1 to the state shown in FIG. Collide with 40. The molten metal 2 that has collided with the flow divider 40 is guided by the flow divider 40 to the runner forming portion 1c and the gate forming portion 1d.

Next, a specific shape of the hollow die-cast product according to this embodiment will be described with reference to FIGS. 3 to 5. FIG.

The hollow die-cast product exemplified in the present embodiment is configured as a die-cast sub-frame 50, and is installed on the rear side of an electric vehicle, for example, to support a battery, a fuel cell, a motor, etc. used in the electric vehicle. It serves as a strength member as an intermediate member used to securely attach vehicle parts to the vehicle body. Further, it is assumed that the die-cast subframe 50 exemplified in the present embodiment is an aluminum alloy cast material formed by casting molten aluminum alloy 2 using a die casting method.

Here, FIG. 3 is a front view of the die-cast sub-frame according to this embodiment, FIG. 4 is a rear view of the die-cast sub-frame according to this embodiment, and FIG. 1 is an external perspective view showing the overall configuration of a die-cast subframe; FIG.

The die-cast sub-frame 50 according to the present embodiment includes a frame-shaped portion 52 having an opening 51 in the center and a substantially rectangular outer shape, and extending outward from each of the four corners of the frame-shaped portion 52 . and an arm portion 53, which is provided with an arm portion 53, so that the overall shape is configured to have a substantially parallel grid shape.

A circular attachment hole 53a is formed at the tip of the arm portion 53, and the die-cast subframe 50 can be attached to the vehicle body using the attachment hole 53a. .

Various mounting portions are arranged on the frame-shaped portion 52, and these mounting portions are used to connect the die-cast sub-frame 50 and parts on the vehicle body side, and to mount various vehicle parts. is feasible. With such a configuration, the die-cast subframe 50 according to the present embodiment can be used as a strength member for supporting a vehicle part when the vehicle part is attached to the vehicle body.

When manufacturing the die-cast sub-frame 50 as a hollow die-cast product according to the present embodiment described above, various improvements have been made to the die-casting method that is performed during the manufacturing. Next, with reference to FIGS. 6 to 10, specific contents of the die-casting method used to obtain the die-cast sub-frame 50 according to the present embodiment will be described. 6 and 7 are diagrams showing the form of the die-cast sub-frame according to the present embodiment immediately after being manufactured by a general die-casting machine. In particular, FIG. A rear view is shown. 8 and 9 are diagrams for explaining the positional relationship between the die-cast sub-frame shown in FIGS. 6 and 7, respectively, and the lower core used when performing the die-casting method. Furthermore, FIG. 10 is a perspective view showing a state in which the die-cast sub-frame and the lower core according to this embodiment are arranged in a fixed mold.

As described above, the die casting apparatus assumed in this embodiment has a fixed mold 10 and a movable mold 20 that can advance and retreat with respect to the fixed mold 10. For the cavity 1a formed in the die casting mold 1, It is of a type in which a pouring port for filling the molten metal 2 is arranged below the cavity 1a. Therefore, as shown in FIGS. 6 and 7, the die-cast sub-frame 50 immediately after manufacture has a biscuit 61 at its lower position.

In this embodiment, a pair of main runners 62 , 62 are provided upward from the biscuit 61 , and the tips of the pair of main runners 62 , 62 are formed in an opening formed in the die-cast sub-frame 50 . It is introduced so as to be arranged side by side at the formation position of 51 . Furthermore, a plurality of runners are formed from the tip of each of the pair of main runners 62 , 62 , and are configured to be connected to the inner peripheral surface of the frame-shaped portion 52 via gates 63 .

Here, in this embodiment, a lower core 25 is used as shown in FIGS. 8 and 9 in order to arrange the pair of main runners 62, 62 so as to ride over the lower portion of the frame-shaped portion 52. . The lower core 25 is used for disposing the pair of main runners 62 , 62 so as to ride over the lower portion of the frame-shaped portion 52 .

The leading ends of the pair of main runners 62, 62 are introduced so as to be arranged side-by-side at the positions where the openings 51 are formed in the die-cast subframe 50. This is a form adopted to improve the hot melt circulation when manufacturing the die-cast sub-frame 50 having a parallelepiped shape. By arranging the main runner 62, runners and gates 63 as shown in FIGS. 6 to 9, it is possible to stably manufacture the die-cast subframe 50 as a hollow die-cast product of good quality.

In addition, in this embodiment, since the configuration shown in FIGS. 6 to 9 is adopted which consists of a pair of main runners 62, 62 and a plurality of runners and gates 63, unnecessary portions such as the gates 63 are cut off when the die casting process is finished. In the die-cast sub-frame 50 as the finished product, gate traces symmetrical with respect to the inner peripheral surface of the frame-shaped portion 52 are formed. Further, due to the use of the lower core 25, the die-cast sub-frame 50 as the final product is formed with a flat portion 52a as a contact trace with the lower core 25 on the lower portion of the frame-shaped portion 52. Become.

Furthermore, the plane portion 52a formed at the bottom of the frame-shaped portion 52 is configured as a vertical plane in a direction orthogonal to the opening direction of the movable mold 20 with respect to the fixed mold 10 constituting the die casting mold 1. is preferred. When die casting is completed and the mold is opened, the lower core 25 moves downward (see FIG. 10). At this time, in consideration of smooth movement of the lower core 25, it is conceivable to form the plane portion 52a as a plane having an angle for draft. However, if the plane portion 52a is formed as an inclined plane, then additional processing is required to form the plane shape. Therefore, in the present embodiment, the plane portion 52a is configured as a vertical plane in a direction orthogonal to the opening direction of the movable mold 20 with respect to the fixed mold 10 constituting the die casting mold 1. Now moves at an angle when moving downward. By adopting such a configuration and method, it is possible to realize a die casting method capable of smooth mold opening operation without requiring extra post-process processing.

Furthermore, in this embodiment, as shown in FIGS. 6 and 7, a pair of sub-runners 65 extending in the left-right direction are provided with respect to the biscuit 61 . Further, at the tip of each of the pair of sub-runners 65, 65, a plurality of runners connected via gates 66 to the vicinity of the left and right end portions of the lower portion of the frame-shaped portion 52 are formed. The reason why such a configuration is adopted is that the molten metal 2 is easily flown upward from the main runner 62 in consideration of the molten metal circulation property of the die-cast sub-frame 50 having a complicated parallel grid shape having the opening 51. It is arranged in consideration of the characteristics of Therefore, gate traces are formed in the vicinity of both left and right ends of the lower portion of the frame-shaped portion 52 . By providing the pair of sub-runners 65, the number of runners and gates 63 extending downward from the tips of the pair of main runners 62, 62 can be reduced or omitted.

Moreover, in this embodiment, since the configuration shown in FIGS. In the die-cast sub-frame 50 as a final product from which the cut-off is removed, a plurality of gate traces are formed in the vicinity of both left and right ends of the lower portion of the frame-shaped portion 52 .

Furthermore, when carrying out the die casting method employing the configuration shown in FIGS. Control is preferred. For example, regarding the injection speed of the molten metal 2 during die casting, when the molten metal 2 reaches the runners and gates 63 formed downward from the tips of the pair of main runners 62, 62, it starts at a low speed. It is preferable to switch to high speed. By doing so, it is possible to suitably prevent the occurrence of a problem called sagging, in which the molten metal 2 falls in an inappropriate state due to the action of gravity within the runner and gate 63 facing downward. becomes. By appropriately controlling the injection speed of the molten metal 2 in this manner, the molten metal circulation property in the cavity 1a is further improved, and it is possible to cast a high-quality die-cast sub-frame 50 .

Although the preferred embodiments of the present invention have been described above, the technical scope of the present invention is not limited to the scope described in the above embodiments. Various changes or improvements can be added to the above embodiments.

In the above-described embodiment, the case where the hollow die-cast product according to the present invention is the die-cast sub-frame 50 has been exemplified and explained. However, hollow die cast products to which the present invention can be applied are not limited to the above-described embodiments, and can be applied to various forms having hollow shapes.

It is clear from the description of the scope of the claims that forms with such modifications or improvements can also be included in the technical scope of the present invention.

1 Die-casting mold 1a Cavity 1b Biscuit forming part (casting port) 1c Runner forming part 1d Gate forming part 2 Molten metal 10 Fixed mold 11 Fixed holder 12 Fixed die 20 Movable mold 21 Movable holder, 22 movable die, 25 lower core, 30 sleeve, 31 plunger tip, 40 shunt element, 50 die-cast subframe (hollow die-cast product), 51 opening, 52 frame-shaped portion, 52a plane portion (lower core contact mark), 53 arm portion, 53a attachment hole, 61 biscuit, 62 main runner, 63 gate, 65 sub-runner, 66 gate.

Claims (5)

A hollow die cast product having an opening in the center and a frame-shaped portion surrounding the opening,
Casting for filling molten metal into a cavity formed in a die-casting mold having a fixed mold and a movable mold that can move forward and backward with respect to the fixed mold by a die-casting apparatus for die-casting the hollow die-cast product. of the type in which the mouth is located below the cavity,
A main runner is provided upward from the casting port, is introduced so that the tip of the main runner is arranged at the formation position of the opening, and a plurality of runners are formed from the tip of the main runner. configured to be connected to the inner peripheral surface of the frame-shaped portion ,
A lower core is provided during die casting at a portion of the cavity formed in the die casting mold where the lower portion of the frame-shaped portion is formed. A hollow die-cast product characterized in that a contact trace with the lower core is formed in the lower part of the frame-shaped part by being formed so as to climb over the lower part . A hollow die cast article according to claim 1,
A hollow die-cast product, wherein the main runners are arranged in a pair and left and right side by side. In the hollow die cast product according to claim 1 or 2 ,
A pair of sub-runners are provided in the casting port in the horizontal direction, and runners are formed at the tips of the pair of sub-runners so as to connect to the vicinity of the left and right ends of the lower portion of the frame-shaped portion. A hollow die-cast product characterized in that runner traces are formed in the vicinity of both left and right ends of the lower portion of the frame-shaped portion. The hollow die cast product according to any one of claims 1 to 3 ,
the frame-shaped portion having the opening in the center and having a substantially rectangular outline shape;
arm portions extending outward from respective four corners of the frame-shaped portion;
By providing the
A hollow die-cast product characterized by being a die-cast sub-frame used as a strength member for supporting a vehicle part when the vehicle part is attached to a vehicle body. A die-casting method, wherein the hollow die-casting product according to any one of claims 1 to 4 is obtained by die-casting using the die-casting apparatus.

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