JP2002103001A - Method for manufacturing insert for cast wheel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an insert for producing a light metal-made wheel for many kinds and small amount of vehicles having a peculiar design based on the liking of a customer apt to be a high cost, at a low cost for a short time. SOLUTION: In a method for manufacturing the insert for cast wheel for forming the peculiar design part making the peculiar design on a disk design part in the cast wheel, a peculiar design original plate provided with the same shape as the peculiar design part, is manufactured and this insert is manufactured by transcribing from the peculiar design shape of the peculiar design original plate.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a nest for forming a unique design of a customer's preference on a part of a wheel, and more particularly to a method for using a light alloy wheel for a vehicle.

[0002]

2. Description of the Related Art In recent years, due to environmental problems, improvement in fuel efficiency of automobiles has been greatly emphasized, and accordingly, reduction in weight of automobiles has been studied. Of these, the demand for weight reduction of components is strict, and there are many cases where iron-based components are changed to light alloy-based components such as aluminum alloys and magnesium alloys. One of these factors is the shift from iron-based to light alloy-based automobile wheels, which is both lightweight and fashionable. At present, the number of passenger cars equipped with aluminum alloy wheels on a line has been considerably increased to about 40 to 45%. Also, wheels of various designs are mounted from the viewpoint of fashion. In addition, a wheel mounted on a line that is mass-produced by a wheel manufacturer in response to an instruction of the overall specification of the wheel from a normal wheel sales company or a car maker will be immersed, so emphasizing individual tastes, There is also a growing demand for wheels with different, unique designs.

One of these is disclosed in Japanese Patent Application Laid-Open No. 59-11410.
No. 1 discloses that a solid space is provided on the outer surface of the disc design portion where a specific expression can be given, and a design of characters, symbols, numerals, etc. is given to this space. However, it is disclosed that many names must be prepared for personal use, and the same number of templates must be prepared. For this reason, when the number of requests is small, it has been proposed to engrave a name on a disk portion of a wheel material by a processing machine.

When a specific design portion such as a name is carved by a processing machine, it is easy to make it concave, but it is difficult to make it convex. In the case of a concave shape, only the portion of the unique design portion needs to be cut, but to make a convex shape, it is necessary to machine the entire periphery of the unique design portion. The cutting portion is contaminated with cutting water or the like, or is deteriorated by frictional heat generated during cutting, and is difficult to use as a return material. It is necessary to use an NC lathe for cutting in both convex and concave shapes. However, if a rotary tool is used, the shape of the corner that forms the corner of the unique design part will be determined by the diameter of the rotary tool. Therefore, a detailed shape cannot be formed. In addition, since a wheel manufactured by processing can perform any wheel if the strength is neglected, it is difficult to give satisfaction of a wheel only for the customer. It is important to go through the manufacturing process of manufacturing the wheels from the first half of the wheel manufacturing process.

[0005]

In consideration of these conditions, it is a condition that the wheel is integrally cast so that a unique design portion is formed. However, when a small number of castings are to be performed, it is necessary to replace the mold and perform the casting, and there have been troublesome problems such as preheating of the mold and replacement of the mold.
Manufacture of a personal wheel by the method using the above-described processing machine requires a lot of man-hours, so that the price is high, it is hardly accepted, and the product is difficult to spread. Although it is preferable to manufacture the nest by providing a nest in the unique design portion, it is still difficult to give a detailed shape even if the nest is manufactured by processing. SUMMARY OF THE INVENTION An object of the present invention is to provide an inexpensive nest for making a variety of types and a small amount of light alloy wheels for a vehicle having a unique design according to the preference of a customer who tends to be expensive, at a low cost and with a short delivery time.

[0006]

According to the present invention, there is provided a method of manufacturing a nest for a casting wheel for forming a unique design portion in which a unique design is drawn on a disk design portion of a casting wheel, the method comprising: Means was used in which a unique design original plate having the same shape was manufactured, and a nest was manufactured by transferring from the unique design shape of the unique design original plate. In this way, it is possible to cope with a casting wheel that is required by each customer to produce a wide variety of products in small quantities, and it is possible to manufacture an inexpensive and high-quality casting wheel. The original design original plate can be manufactured by laser molding, laser processing of rubber, laser processing of powder resin, or the like.

[0007] At this time, the original design original plate can be easily and precisely formed by molding with a photo-curable resin. In two-dimensional stereolithography, by irradiating light from one side to the photocurable resin through a printed film or the like, light can be easily irradiated almost only in two-dimensionally necessary parts,
It is relatively cheap in terms of cost. Depending on the resin, a convex portion hardened because light is scattered inside is formed with a slight gradient. If the design is fine, there is a risk that the cured projections will stick together, so it is necessary to make the unique design part a unique design with a predetermined gap, but this gradient is It is very important as a draft when releasing a casting. Therefore, in order to satisfy the casting conditions, it is preferable to set the resin material and the light source to be used so as to have a draft of 7 ° or less, more preferably 5 ° or less. In addition, since the curing amount of the photocurable resin varies depending on the light amount of light, irradiation time, and the like, it is important to appropriately set the curing amount.

In three-dimensional stereolithography, a photocurable resin is molded by tracing a thin resin layer with a thin laser beam. It is possible to make the engraving of such a shape part fine. In addition, three-dimensional modeling is also possible, and nesting can be manufactured by repeatedly forming a wax to form a wax mold, removing the wax after casting with gypsum. In particular, in fin type, spoke type, and mesh type wheels, the draft angle of the side surface such as the spoke portion is reduced to give a sharp feeling. It is necessary to vertically pull out the mold for casting the disk design part from the disk design part, and it is important to form the nest so that a predetermined draft angle is also provided. In that respect, three-dimensional stereolithography capable of strict control is preferable.

For example, an advantage of the laser scanning type three-dimensional stereolithography as an example is that a free gradient can be provided in the height direction. In the method using the negative, the resin is cured by irradiating light from the back of the negative for a certain period of time, so that the resin after molding is moved in the height direction by the straightness of light of the light source and the diffusion of light in the resin. (Irradiation direction of light). On the other hand, in the laser scanning type three-dimensional stereolithography, since the thickness of the hardened layer is limited to an extremely thin layer, the gradient in the height direction can be extremely small for each layer. Further, an arbitrary shape can be formed in the height direction by laser scanning. The disadvantage of this method is that it is necessary to create a shape in the height direction. That is, since the image data sent from the customer is two-dimensional data, it is necessary to extract a contour based on this data, add data in the height direction, and process the data into three-dimensional data. This task must be to create the shape using and absolutely human decision for automation is difficult 3-dimensional CAD or the like. If processing of image data is automated due to the development of software, three-dimensional stereolithography has advantages, and in terms of manufacturing cost and time, negative stereolithography is more advantageous.

[0010] Further, if the nest is merely fitted into the mold with the mold closed during casting, the nest may be separated from the mold during casting. Therefore, it is desirable to provide a structure in which an exhaust pipe is provided in the concave portion of the nest portion and the nest is sucked into the nest portion. Also, even if a permeable material such as gypsum is used as the nesting material, excess air is sucked out from the exhaust pipe, so the gas contained in the nesting expands due to heat during casting and the casting surface condition Does not worsen.

Here, the disk design portion of the wheel refers to a portion representing the basic design of the entire wheel, such as the positions of the decorative windows and spokes of the wheel, the entire arrangement of the dish type, etc. Refers to the parts with unique features such as letters, numbers, marks, names, family crests, patterns and pictures drawn on spokes and dishes in the disc design department. Further, the unique design portion refers to a portion formed by nesting other than the unique design on the disc design portion, and the disc design portion may have a unique design portion having irregularities on the surface, and may have no irregularities. It may have a unique design section. Also,
As described above, a unique design having irregularities is formed inside the unique design portion. The material that forms the nest is
Sand, ceramic, gypsum and the like can be mentioned. Since it must be removed from the cast product (wheel) after casting, a material that is strong at the time of casting and is fragile after casting is preferred.

Since the nest can be manufactured at low cost, it can be attached to a cast product (wheel) for each shot. This requires a small amount of casting, so when casting wheels with the following different unique design parts, if the nest is fixed in the mold, the casting operation must be interrupted and the fixed nest replaced. There is. The reason why the nest is attached to the product every shot is to prevent the replacement time from being excessively long, perform the casting operation smoothly and continuously, and perform the casting operation without disturbing the casting conditions such as the mold temperature.

The nesting may be such that the unique design is expressed in a convex shape and the entire unique design portion is formed in a convex shape, or the frame of the unique design portion is formed in a convex shape, or characters, numerals, patterns or marks are formed. Alternatively, it may be formed so that only the unique design such as is convex. Alternatively, the frame may be once formed in a convex shape, and a shape in which a unique design is formed in a concave shape. The height of the convex shape is desirably 10 mm or less, more preferably 5 mm or less, from the surface of the disc design portion where the unique design portion exists. It is necessary to form a deep groove on the nest side, and there is a fear that poor flow of the molten metal occurs at the time of casting, or a decrease in strength of the nest itself. Also,
Although the strength of the wheel is slightly increased by the convex shape, when considering the rotational balance of the wheel, if it is too high, the so-called wheel balance will be lost.

The nesting may be such that the unique design is expressed in a concave shape and the entire unique design portion is formed in a concave shape, or the entire unique design portion is formed in a concave shape, and characters, numerals, patterns, marks, etc. It may be formed so that only the unique design has a convex shape. Alternatively, the unique design portion may be once framed in a convex shape, and the unique design may be formed in the concave shape. The depth of the concave portion is 6 degrees from the surface of the disc design portion where the unique design portion is located.
A depth shallower than mm is desirable. If a too deep concave portion is formed, it is necessary to form a thin and protruding portion on the nest side, which is not preferable in terms of strength. In addition, there is a high possibility that the wheel balance will be lost, and safety strength may not be maintained. The unevenness expressing the unique design of the unique design section is not limited to the above, and various combinations such as unevenness, unevenness, unevenness and the like can be considered infinitely.

[0015]

Embodiments of the present invention will be described below in detail. (Embodiment 1) FIG. 1 shows a flowchart for manufacturing a nest according to the present invention. First, the customer sends basic data that will be a unique design. This may be handwritten paper or digital image data having a unique design delivered by data transfer means such as the Internet. On the basis of the basic data, a unique design film is formed such that a portion having a convex shape in the cast wheel has a light transmitting property and a portion having a concave shape has a light shielding property. In this embodiment, the basic data is first printed on paper. In the normal base data, the convex portion is drawn in black and the concave portion is drawn in white by the cast wheel. Therefore, the paper surface was scanned and taken in as image data, and black-and-white inversion was performed. Naturally, if the base data is such that the convex part is white and the concave part is black,
The image data scanned without performing the black and white reversal may be used as it is. The image data obtained in this way is printed on a light-transmitting film with a light-shielding paint to produce a unique design film in which only the convex portions are light-transmitting. FIG. 3 shows an example of the unique design film 31. In FIG. 3, white characters 32 are light-transmitting portions that become convex portions on the wheel, and black characters 33 are light-shielding portions that become concave portions. The translucent white circle portion 34 formed at the end is a portion which becomes a positioning projection for a nested type described later.

FIG. 5 shows a simplified diagram of a device configuration for manufacturing a unique design original plate using a photocurable resin. FIG.
Reference numeral 30 denotes a translucent case for containing the photo-curable resin 43. As shown in FIG. 5A, a unique design film 31 is arranged below the case 30. When light is irradiated from the direction of the unique design film, light is transmitted from the light-transmitting portions 32 and 34 that become convex portions on the casting wheel, and the photo-curable resin 43 is gradually cured from below to above, and The design original plate convex portion 41 is formed. The light source is 300mm so that it is transmitted perpendicular to the film.
Irradiation was performed from a distance as described above.

In the above state, the cured convex portion 41
May not be fixed to the convex portions. Therefore, after forming the convex portion 41 to a predetermined size, FIG.
Then, the unique design film 31 is removed, and the lower front surface of the case 30 is irradiated with light for a certain period of time to cure the entire lower surface of the photo-curable resin to form the fixing plate 42. Thereby, the original design original plate 40 in which the convex portions are formed in the integrated sheet shape is manufactured.

Next, as shown in FIG. 6, a nesting die 50 is formed on a positioning projection formed on the resin-made original design original plate.
To match. This nesting mold is provided with an inclination so as to fit with a concave nesting portion for nesting formed in an actual casting mold. Plaster was poured into a space formed by the original design original plate 40 and the nesting mold 50, solidified, and sintered to produce a nest for casting out a unique design. The slope of the section relative to the unique design of the nest was 4.5 °.

FIG. 2 shows an example of casting a light alloy wheel for a vehicle according to the present invention, schematically showing equipment and a mold when an aluminum alloy wheel is cast by ordinary low pressure casting. The figure in the state where it fastened is shown. A holding furnace 2 is provided in the closed container 1, and a lower die plate 3 is mounted on the closed container 1 to seal the closed container 1. The lower die plate 3 is provided at its center with a stalk 4 for replenishing the molten metal 5 of the aluminum alloy to the mold, and a lower end of the stalk 4 is immersed in the molten metal 5 in the holding furnace 2. The upper end of the stalk 4 is connected to the lower die 8 and the lower gate 8 of the lower die 8 via the gate bush 6 fitted into the lower die 8 of the die.
It is connected to. The lower die 8 of the die is attached to the lower die plate 3. The lower die 8 is a so-called fixed die, and is a surface on which a disk design portion 9 is formed on a wheel. The lower die 8 is provided with a nest 18 into which a nest 17 forming the unique design part 100 is inserted. On both sides is a laterally movable mold 10 which forms the outer peripheral surface of the rim 11 of the wheel.
The upper mold 12 of the mold is attached to an upper die plate 13. The upper mold 12 is a so-called movable mold, and forms a surface 14 for attaching a wheel to a vehicle and an inner peripheral surface of the rim portion 11.

The casting operation is performed according to the following procedure. After inserting the insert 17 into the insert 18 of the lower mold 8 and closing the molds of the horizontal movable mold 10 and the upper mold 12 by a mold opening / closing mechanism (not shown), the mold is opened to 0.02- A pressurized gas of 0.05 MPa is fed into the closed container 1 through the pressurized gas feed pipe 15. Approximately 6 in the holding furnace 2
The molten aluminum 5 held at 50 ° C. is pushed up through the stalks 4 and enters the cavities 16 in the mold maintained at a mold temperature of 350 to 500 ° C. The cavity portion 16 of the mold is coated with a coating mold that serves both heat retention and release. After about 4 to 5 minutes, the pressurization is stopped, the molten metal 5 in the unsolidified stalk 4 is returned to the holding furnace 2, and the molten metal in the mold is waited for solidification. Solidification of the molten metal in the mold is completed,
When the removal temperature of 400 ° C. is reached, the mold is opened and the cast product (wheel) is removed. This cycle is repeated and the product is cast. In order to perform the casting operation in a constant cycle, the insert 17 was attached to the product for each shot of the casting. As a result, it is possible to cast the casting at a constant casting cycle without any extra man-hours during the casting operation, that is, to keep the casting conditions constant, and it is possible to cast aluminum alloy wheels with good quality and a well-defined unique design. Was obtained.

FIG. 4 is a cross-sectional view when the nest is inserted into the nest portion of the lower die. An exhaust pipe 20 is provided in the concave portion of the nest portion 18 so that the nest 17 is sucked to the nest portion 18. The exhaust pipe used was a cylindrical one having an inner diameter of 7 mm. As an intake mechanism, the other end of the exhaust pipe extending to the outside of the mold is vertically embedded in the air duct 21. Ventilation pipe 21
The pressure in the exhaust pipe was reduced by flowing air into the inside, so that air was exhausted from the exhaust pipe 20 toward the ventilation pipe 21.
Compressed air was used as a means for flowing air through the ventilation pipe. The inside diameter of the ventilation tube was 10 mm.

(Embodiment 2) FIG. 7 shows a simplified diagram of another device configuration for manufacturing a unique design original plate. Example 1
In contrast to the two-dimensional stereolithography of the unique design model of No. 1, the laser scanning type three-dimensional stereolithography was used. First,
The molding stage 61 that can move up and down is moved to the ultraviolet curing resin tank 6
7 and the depth from the upper surface of the stage to the liquid surface
The position of the stage 61 was adjusted so as to be 1 mm to 0.01 mm. By scanning the resin 62 on the stage 61 with the laser light 66 from the laser light source 65 together with the mirror 68, the light-irradiated portion was cured to the liquid surface depth. After the formation of the first layer was completed using the cured layer 63 as the first layer, the stage was immersed by about 1 mm to 0.01 mm, and the second layer was similarly formed by laser scanning. This operation was repeated for a desired height to form a target original design original plate 64. In the present embodiment, molding was performed so as to be a unique design portion having three steps. An aluminum wheel was cast in the same manner as in Example 1 using the original design original plate manufactured by the three-dimensional stereolithography. As a result, it was possible to obtain a high-quality wheel having a unique design with steps.

In the description of the casting method of the present invention, the method of casting by low pressure casting has been described. However, it is needless to say that the casting method is not limited to this, but can be applied to gravity casting and die casting. In the above description, the casting method when the unique design is provided in the disk design portion of the aluminum alloy wheel of the one-piece casting (one piece) has been described, but the unique design is provided in the disk design portion of the two-piece or three-piece wheel. It can be applied to any situation. Although the alloy material to be cast has been described as an aluminum alloy wheel, it can be applied to a vehicle wheel made of an alloy such as a magnesium alloy or a titanium alloy as long as it has fashionability.

[0024]

As described above, the nesting is manufactured by the above-described method, so that a light alloy wheel for a vehicle having a unique design according to the customer's preference can be cast in a small amount and efficiently, and the cost of the customer needs can be reduced with a short delivery time. Can supply.

[Brief description of the drawings]

FIG. 1 is a manufacturing flowchart of a nest.

FIG. 2 is an example of a casting machine using the nest of the present invention.

FIG. 3 is an example of a unique design film used in the present invention.

FIG. 4 shows an exhaust mechanism of a nest portion provided in a mold.

FIG. 5 is an example of a two-dimensional stereolithography resin molding method used for manufacturing a unique design original plate.

FIG. 6 is an example of a transfer method from a nested original design original plate.

FIG. 7 is an example of a three-dimensional stereolithography resin molding method used for manufacturing a unique design original plate.

[Explanation of symbols]

8 lower die, 9 spoke cavity, 10 horizontal die, 1
2 Upper die, 17 nesting, 18 nesting part, 20 exhaust pipe, 21 ventilation pipe, 30 case, 31 unique design film, 40 64 unique design original plate, 41 (unique design original plate) convex part, 42 fixing plate, 43 62 light curing Resin, 50 nesting type, 61 modeling stage, 6
5 Laser light source

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) B60B 3/06 B60B 3/06 (72) Inventor Kenji Usui 5200 Sanigajiri, Kumagaya-shi, Saitama Hitachi Metals, Ltd. Inside the Kumagaya Light Alloy Factory (72) Inventor Koichi Arai 5200 Sankajiri, Kumagaya City, Saitama Prefecture Hitachi Metals Co., Ltd. Term (reference) 4E093 FA03 FC01 NA04 NB08 NB10 VA01

Claims (4)

[Claims] 1. A method of manufacturing a nest for a casting wheel for forming a unique design portion in which a unique design is drawn on a disk design portion of a casting wheel, the original design plate having the same shape as the unique design portion. And manufacturing by transferring from the unique design shape of the original design original plate. 2. The method for manufacturing a nest for a wheel according to claim 1, wherein the original design original plate is formed of a photocurable resin. 3. The method of manufacturing a unique design original plate by curing the photo-curable resin, wherein light is applied so that a side surface of a convex portion and / or a concave portion of the unique design original plate has a gradient of 7 ° or less. 3. The method for manufacturing a nest for a wheel according to 2. 4. The method for producing a nest for a wheel according to claim 1, wherein the nest is transferred from an original design plate using gypsum as a nest material.