JP4779077B2 - Vehicle wheel and manufacturing method thereof - Google Patents

Description

  The present invention relates to a vehicle wheel mounted on a vehicle such as an automobile and a method for manufacturing the vehicle wheel, and more particularly to a vehicle wheel and a method for manufacturing the vehicle wheel that can reduce resonance generated in a tire during rotation.

  In general, a wheel mounted on an automobile or the like includes a vehicle wheel having a rim provided on the outer peripheral side of a disk and a tire provided on the outer peripheral side of the rim. A tire air chamber formed of an annular sealed space is formed between the rim of the vehicle wheel and the tire.

  By the way, it is known that air column resonance occurs in the tire air chamber during traveling of the vehicle, and this air column resonance is a cause of worsening noise generated from the vehicle. Note that air column resonance means that random vibration transmitted from the road surface to the tire vibrates the air in the tire air chamber, and as a result, near the air column resonance frequency of the tire air chamber (for example, around 250 Hz for a tire for a normal passenger car). ), A resonance phenomenon occurs, and a resonance sound is generated.

Therefore, in order to reduce such air column resonance, for example, a vehicle wheel described in Patent Document 1 is known. As shown in FIG. 9A, the vehicle wheel includes auxiliary air chambers 51, 51... Formed in the circumferential direction inside the bead seat portion 50, 50 in the radial direction, Are connected to a tire air chamber 53 formed between the inner circumferential surface of the tire T and the rim 52, and the auxiliary air chambers 51, 51,. The parts 51a, 51a,... Are formed by core casting.
According to such a vehicle wheel, the tire air chamber 53 and the auxiliary air chambers 51, 51,... Communicate with each other through the communication portions 51a, 51a, so that the air in the communication portions 51a, 51a,. The air in the auxiliary air chamber acts as a “spring” and constitutes a sound resonator (so-called Helmholtz sound absorber), so that noise associated with air column resonance can be reduced.
JP 2004-299484 A

In general, since it is expensive to manufacture a mold for manufacturing a vehicle wheel, it is desirable to manufacture a vehicle wheel by diverting a conventionally used mass production mold.
From this point of view, when considering a mold for manufacturing the above-described conventional vehicle wheel, for example, a general mold as shown in FIG. In this case, the core 55 for forming the auxiliary air chamber 51 and the communication portion 51a is placed at a predetermined position by a support portion 56 (illustrated by a broken line) provided from the mold K through the rim flange 54a at the end of the disk 54. Fixed.

  However, in the manufacture of the vehicle wheel by casting, in which the core 55 is disposed in the mold K, a hole for removing the core 55 after demolding is formed on the disk 54 (rim flange 54a) side. It is necessary to close this after demolding, and the design surface on the disk 54 side is damaged.

  Therefore, the present invention provides a vehicle wheel that can divert a conventional mass-production mold and reduce the cost, and that does not impair the design surface of the disk, and a method for manufacturing the same. This is the issue.

The vehicle wheel according to claim 1 of the present invention that has solved the above problems communicates with a disk, a rim provided on the outer peripheral side of the disk, and a tire air chamber formed when a tire is attached to the rim. to a sub air chamber, a fixed mold having a shape corresponding to the vehicle outer side of the disk, the first movable mold having a shape corresponding to the radially outer side of the rim, the radially inner side of the rim And a second movable mold having a shape corresponding to the inside of the disk of the disk, and a vehicle wheel cast using a casting mold , wherein the casting mold is formed of the rim. A support portion that has a shape corresponding to a part of the rim flange portion in the circumferential direction, and is attached to a concave groove provided in a portion corresponding to a radially outer side of the rim flange portion in the fixed mold; Mounting on the part A rim formed by the first movable mold and the second movable mold, the support portion being housed in the first movable mold during mold clamping. The core functions as a mold that forms a part of the chamber, and the core is arranged in the rim chamber from the outer peripheral side of the rim chamber in a state where the support portion is accommodated in the first movable mold when the mold is clamped. The auxiliary air chamber is formed by casting using the core.

According to the first aspect of the present invention, the core forming the auxiliary air chamber is formed from the outer peripheral side of the rim chamber for forming the rim via the support portion attached to the concave groove of the fixed mold. since it is arranged is supported, hole removing the core after demolding, it will be formed on the rim rather than the disk side. Therefore, the design surface of the disc is not damaged by the hole for removing the core as in the prior art. In addition, since the core that forms the secondary air chamber is supported from the outer periphery of the rim chamber, the mass-production molds that have been used in the past can be diverted without any problems, and changes in manufacturing equipment can be minimized. The cost can be reduced.

Further, as described above, since the core is supported from the outer peripheral side of the rim chamber via the support portion, the hole for removing the core after demolding communicates the auxiliary air chamber and the tire air chamber. It can be used as a communication hole. Accordingly, it is not necessary to provide a communication hole for communicating the auxiliary air chamber and the tire air chamber after demolding by machining or the like, and the manufacturing process can be simplified correspondingly.
Further, as described above, since the hole for extracting the core is not formed on the disk side, there is no possibility of air leakage from the auxiliary air chamber, and the advantage of excellent airtightness can be obtained. Furthermore, the process for inspecting the air leak can be eliminated.

  Furthermore, since the support portion is configured to be attached to the fixed mold, there is no possibility that the support portion is displaced after attachment as compared with a configuration in which the support portion is attached to the movable die. Therefore, a vehicle wheel that can improve the yield is obtained. In addition, this eliminates the need to firmly fix the support portion to the fixed mold, and allows the support portion to be easily attached, resulting in an advantage that manufacture is simplified.

  The vehicle wheel according to a second aspect is the vehicle wheel according to the first aspect, wherein the core is formed integrally with the support portion.

According to the second aspect of the present invention, since the core is formed integrally with the support portion, the support portion can be simultaneously formed at the stage of forming the core, and the core and the support portion can be made inexpensively. Obtainable.
Moreover, since it forms integrally, the joining boundary part at the time of shape | molding separately becomes smooth, the amount of casting burr generation after casting reduces, and the work man-hour of casting burr removal is reduced.

  The vehicle wheel according to a third aspect is the vehicle wheel according to the first or second aspect, wherein the auxiliary air chamber is formed in a circumferential direction radially inward of a bead seat portion formed in the rim. It is characterized by that.

  According to the third aspect of the present invention, the auxiliary air chamber can be formed using a relatively thick portion of the rim.

  The vehicle wheel according to a fourth aspect is the vehicle wheel according to the third aspect, wherein the core is supported by the support portion at a position away from the bead seat portion.

  According to the fourth aspect of the present invention, since the core is supported by the support portion at a position away from the bead seat portion, the hole for removing the core after demolding, that is, the auxiliary air chamber and the tire air A communication hole communicating with the chamber can be provided at a position away from the bead seat portion. This prevents the communication part from being blocked by the bead part of the tire.

  The vehicle wheel according to claim 5 is the vehicle wheel according to any one of claims 1 to 4, wherein a plurality of the auxiliary air chambers are formed at predetermined intervals in a radial direction of the rim. It is characterized by that.

  According to the fifth aspect of the present invention, the capacity of the auxiliary air chamber required for reducing the air column resonance can be obtained by the total capacity of the plurality of auxiliary air chambers, thereby forming the auxiliary air chamber. A vehicle wheel with a certain degree of design freedom is obtained.

Moreover, the manufacturing method of the vehicle wheel according to claim 6 includes the step of molding the core and the support portion when manufacturing the vehicle wheel according to any one of claims 1 to 5. , de state in which the core, which is molded is placed on the rim chamber by the support portion from the outer peripheral side of the rim chamber, and attaching said support portion to the groove of the fixed mold, after pouring And a step of removing the core by molding.

According to the invention described in claim 6, since the core forming the auxiliary air chamber is arranged and supported from the outer peripheral side of the rim chamber via the support portion attached to the concave groove of the fixed mold, A hole for removing the core after demolding is formed not on the disk side but on the rim side, and the design surface of the disk is not damaged by the hole for removing the core. In addition, since the core that forms the secondary air chamber is supported from the outer periphery of the rim chamber, the mass-production molds that have been used in the past can be diverted without any problems, and changes in manufacturing equipment can be minimized. The cost can be reduced.

  ADVANTAGE OF THE INVENTION According to this invention, while being able to divert the conventional mass production type metal mold | die, it can aim at the reduction of cost, and the vehicle wheel which does not impair the design surface of a disk, and its manufacturing method are obtained. .

  Hereinafter, embodiments of a vehicle wheel according to the present invention will be described in detail with reference to the drawings as appropriate.

In the drawings to be referred to, FIG. 1 is a partial sectional view showing a state in which a tire is assembled to a vehicle wheel according to an embodiment of the present invention.
A vehicle wheel 10 shown in FIG. 1 constitutes a vehicle wheel 1 with a tire 20 attached thereto.

  As shown in FIG. 1, the vehicle wheel 10 includes a disk 11 and a rim 12 that is provided on the outer peripheral side of the disk 11 and on which a tire 20 is mounted. When the tire 20 is attached to the rim 12, The auxiliary air chamber 14 communicating with the tire air chamber 13 can be provided.

The vehicle wheel 10 is made of, for example, a material such as an aluminum alloy or a magnesium alloy, and is integrally formed by casting as described later.
The disk 11 is provided for connection to a hub (not shown), and a surface disposed on the outer side (outer side) of the vehicle is a design surface M.

  The rim 12 has bead sheet portions 12A and 12A ′ at both ends in the width direction, and rim flange portions 12B and 12B ′ that are bent in an L shape outwardly from the bead sheet portions 12A and 12A ′. Have. The bead portions 21 and 21 'of the tire 20 are assembled to the bead seat portions 12A and 12A' so that the bead portions 21 and 21 'do not come off sideways (outside in the width direction) by the rim flange portions 12B and 12B'. It has become. In addition, humps 12C and 12C ′ are formed on the inner side of the bead seat portions 12A and 12A ′ so as to rise slightly from the bead seat portions 12A and 12A ′. The bead portions 21 and 21 'are prevented from falling inward. A well portion 12D for dropping the bead portions 21, 21 'when assembling the tire 20 is provided between the humps 12C, 12C'.

  The auxiliary air chamber 14 is formed on the radially inner side of one bead seat portion 12A of the rim 12 and includes a communication hole 14a that communicates with the tire air chamber 13 to reduce air column resonance that occurs when the vehicle travels. Play a role. In the present embodiment, as shown in FIG. 2, a total of four auxiliary air chambers 14 are formed at predetermined intervals in the circumferential direction. Thus, by forming the plurality of auxiliary air chambers 14, 14... In the circumferential direction of the rim 12, the sound absorption characteristics can be stabilized. .. Are formed when the vehicle wheel 10 is formed by core casting.

Here, the core for forming the auxiliary air chambers 14, 14,... Will be described with reference to FIGS. FIG. 3 is an enlarged perspective view showing a core supported by the support portion (shown in a partial cross section), and FIG. 4 is a view showing a casting mold in a mold-clamping state used for manufacturing the vehicle wheel of the present invention. It is principal part sectional drawing in the width direction of a rim | limb. The sub air chambers 14, 14,... Are the same, and therefore, only one sub air chamber 14 will be described below.
As shown in FIG. 3, the core 30 is formed in a streamlined cross section that narrows toward the lower portion, and is formed below the upper portion 31 a of the support portion 31 formed in a substantially L shape by the connecting portion 30 a. It is provided in a suspended state.
The support portion 31 has an inner surface corresponding to the bead seat portion 12A and the rim flange portion 12B (see FIG. 1). That is, the support portion 31 functions as a mold that forms part of the bead seat portion 12A and the rim flange portion 12B (see FIG. 1) of the vehicle wheel 10 (see FIG. 1) during casting. Further, the support portion 31 is formed in a shape in which the lower portion 31b can be fitted in accordance with a concave groove 40a provided in a fixed lower die (fixed mold) 40.

  In the present embodiment, the core 30 (including the connecting portion 30a) and the support portion 31 are integrally formed with a mold made of sand. And the connection part 30a forms the hole for extracting the core 30 by removing after mold removal so that it may mention later. This hole functions as the communication hole 14a described above after the core 30 is removed.

  Then, as shown in FIG. 4, such a core 30 is fixed to the fixed lower die 40 by fitting the lower portion 31 b of the support portion 31 into the concave groove 40 a of the fixed lower die 40. The rim 12 (see FIG. 1) is disposed from the outer peripheral side of the rim chamber 45 toward the rim chamber 45. At this time, the core 30 is supported by the support portion 31 at a position away from the position where the bead sheet portion 12A is formed. That is, the connecting portion 30a is located on the well portion 12D side that is out of the position where the bead sheet portion 12A is formed.

  The tire 20 includes a tire main body that contacts a road surface (not shown), and an inner liner that is attached to the entire inner periphery of the tire main body. The inner liner is configured by the bead portions 21 and 21 ′. have. These bead portions 21 and 21 ′ are attached in a state where they are elastically adhered to the bead seat portions 12 A and 12 A ′ of the rim 12. As a result, the bead seat portions 12A, 12A 'and the bead portions 21, 21' of the rim 12 are hermetically sealed, and a tire air chamber 13 formed of an annular sealed space is formed therein.

Next, a method for manufacturing the vehicle wheel 10 will be described.
FIGS. 5A to 5D are views for explaining a method for manufacturing the vehicle wheel 10 and are schematic cross-sectional views in the width direction of the rim 12.
First, the core 30 and the support portion 31 are integrally molded using a core molding die (not shown). Thereafter, as shown in FIG. 5A, the lower portion 31 b of the support portion 31 is fitted into the concave groove 40 a of the fixed lower die 40, and the core 30 is fixed to the fixed lower die 40 via the support portion 31.
Subsequently, as shown in FIG. 5B, the side mold ( first movable mold) 41 is slid to a predetermined position with respect to the fixed lower mold 40 and the upper mold ( second movable mold). 42 is lowered to a predetermined position toward the fixed lower mold 40 to combine the molds. In the side mold 41, a recess 41a is formed in advance in a portion corresponding to the support portion 31, and the support portion 31 is completely accommodated in the recess 41a in a state where the side mold 41 is slid to a predetermined position. (See FIG. 5C). That is, the side mold 41 is formed with four recesses 41a, 41a,... Corresponding to the position of the auxiliary air chamber 14.

  Thereafter, an aluminum alloy melted by heating to 800 ° C. in an electric furnace or the like is poured from a sprue 42a at one end of the upper mold 42. Then, when the aluminum alloy is cooled, it is removed from the mold, and as shown in FIG. 5 (d), the support portion 31 is dropped and the core 30 is pulverized and removed from the communication hole 14a by applying vibration. Thereby, the vehicle wheel 10 is completed.

  According to the vehicle wheel 10 thus molded, the core 30 forming the auxiliary air chamber 14 is supported from the outer peripheral side of the rim chamber 45 via the support portion 31 attached to the fixed lower mold 40. Therefore, a hole (communication hole 14a) for removing the core 30 after demolding is formed not on the disk 11 side but on the rim 12 side. Therefore, unlike the conventional case, the design surface M of the disk 11 is not damaged by the hole through which the core 30 is pulled out. Moreover, since the core 30 forming the auxiliary air chamber 14 is supported from the outer peripheral side of the rim chamber 45, the conventionally used mass production mold can be used without any problem, and the production equipment can be changed. Can be minimized and the cost can be reduced.

Further, as described above, since the core 30 is supported from the outer peripheral side of the rim chamber 45 via the support portion 31, a hole for removing the core 30 after demolding is formed in the auxiliary air chamber 14 and the tire air. It can be used as a communication hole 14 a that communicates with the chamber 13. Thereby, it is not necessary to provide the communication hole 14a by machining after demolding, and the manufacturing process can be simplified correspondingly.
Further, as described above, since the hole for extracting the core 30 is not formed on the disk 11 side, there is no possibility that air leaks from the auxiliary air chamber 14, and there is an advantage that the airtightness is excellent. Furthermore, the process for inspecting the air leak can be eliminated.

  Furthermore, since the support part 31 is a structure attached to the fixed lower mold | type 40, compared with the structure where the support part 31 is attached to the movable metal mold | die of the side type | mold 41 or the upper mold | type 42, for example, the support part 31 after attachment. There is no risk of misalignment. Therefore, the vehicle wheel 10 capable of improving the yield is obtained. In addition, this eliminates the need to firmly fix the support portion 31 to the fixed lower mold 40, and allows the support portion 31 to be easily attached, resulting in an advantage that manufacture is simplified.

Further, since the core 30 is formed integrally with the support portion 31, the support portion 31 can be formed at the same time when the core 30 is formed, and the core 30 and the support portion 31 can be obtained at low cost. it can.
Moreover, since it forms integrally, the joining boundary part at the time of shape | molding separately becomes smooth, the amount of casting burr generation after casting reduces, and the work man-hour of casting burr removal is reduced.

  Further, since the auxiliary air chamber 14 is formed in the circumferential direction on the radially inner side of the bead seat portion 12A formed on the rim 12, the auxiliary air chamber 14 using a relatively thick portion of the rim 12 is used. The formation of is realized.

  Further, since the core 30 is supported by the support portion 31 at a position removed from the bead sheet portion 12A, the hole for removing the core 30 after demolding, that is, the communication hole 14a is located at a position removed from the bead sheet portion 12A. Can be provided. This prevents the communication hole 14 a from being blocked by the bead portion 21 of the tire 20.

  Further, since a plurality of sub air chambers 14, 14,... Are formed at predetermined intervals in the radial direction of the rim 12, the capacity of the sub air chambers necessary for reducing the air column resonance can be reduced to a plurality of sub air chambers. The vehicle wheel 10 can be obtained with the total capacity of the auxiliary air chambers 14, 14..., And has a degree of design freedom when forming the auxiliary air chambers 14, 14.

As mentioned above, although this embodiment was described, this invention is not limited to this, It can implement in the following forms.
In the present embodiment, the core 30 and the support portion 31 are integrally formed. For example, as shown in FIG. 6, these are formed separately and the connecting portion 30 a of the core 30 is the support portion 31. May be configured by being inserted into a mounting hole (not shown) and fixed with an adhesive or the like. In this case, since the core 30 and the support part 31 can be separately molded, the degree of freedom in shape increases.
Moreover, as shown in FIG. 7, the support part 31 may be divided into an upper part 31A and a lower part 31B, and the core 30 may be formed integrally with the upper part 31A. In this case, since the joining surface between the upper part 31A and the lower part 31B can be formed flat, both can be easily joined with an adhesive or the like.

  Further, as shown in FIG. 8, the cores 30, 30... Forming the sub air chambers 14, 14... Are extended in the circumferential direction, and the auxiliary air chambers 14, 14. May be provided. By forming such auxiliary air chambers 14, 14..., It is possible to more effectively reduce noise associated with air column resonance. Further, by changing the size of the cores 30, 30..., The auxiliary air chambers 14, 14.

It is sectional drawing which shows the state which assembled | attached the tire to the vehicle wheel which concerns on one embodiment of this invention. It is a model side view of a wheel for vehicles similarly. It is the expansion perspective view (partial cross section) which showed the core supported by the support part. It is principal part sectional drawing in the width direction of the rim | limb of the casting mold in the mold clamping state used in order to manufacture the wheel for vehicles of this invention. (A)-(d) is a schematic explanatory drawing for demonstrating the manufacturing method of the wheel for vehicles. It is the perspective view which showed the other assembly | attachment of the core. It is the perspective view which showed the other assembly | attachment of the core. It is a model side view of the wheel for vehicles which formed the auxiliary air chamber long in the peripheral direction. (A) (b) is explanatory drawing of a prior art.

Explanation of symbols

10 Vehicle Wheel 11 Disc 12 Rim 12A Bead Seat Part
12B Rim flange portion 13 Tire air chamber 14 Sub air chamber 14a Communication hole 20 Tire 30 Core 30a Connection portion 31 Support portion 40 Fixed lower mold (fixed mold)
40a groove
41 Side mold (first movable mold)
42 Upper mold (second movable mold)
45 Rim room

Claims (6)

Comprising a disk and a rim provided on an outer peripheral side of the disc, and a sub air chamber communicating with the tire air chamber can when the tire on the rim is attached,
A stationary mold having a shape corresponding to the vehicle outer side of the disk;
A first movable mold having a shape corresponding to the radially outer side of the rim;
A vehicle wheel cast using a casting mold comprising: a second movable mold having a shape corresponding to a radially inner side of the rim and a vehicle inner side of the disk ;
The casting mold is
A support portion that has a shape corresponding to a part of the rim flange portion of the rim in the circumferential direction, and is attached to a concave groove provided in a portion corresponding to a radially outer side of the rim flange portion in the fixed mold; ,
A core attached to the support,
The support portion is housed in the first movable mold during mold clamping, and forms a part of a rim chamber formed by the first movable mold and the second movable mold. Function,
The core is arranged in the rim chamber from the outer periphery side of the rim chamber in a state where the support portion is accommodated in the first movable mold at the time of mold clamping.
The vehicle air wheel , wherein the auxiliary air chamber is formed by casting using the core.   The vehicle wheel according to claim 1, wherein the core is formed integrally with the support portion.   3. The vehicle wheel according to claim 1, wherein the auxiliary air chamber is formed in a circumferential direction radially inward of a bead seat portion formed in the rim.   The vehicle wheel according to claim 3, wherein the core is supported by the support portion at a position away from the bead seat portion.   The vehicle wheel according to any one of claims 1 to 4, wherein a plurality of the auxiliary air chambers are formed at a predetermined interval in a radial direction of the rim. In manufacturing the vehicle wheel according to any one of claims 1 to 5, a step of molding the core and the support portion, and the molded core from the outer peripheral side of the rim chamber Including a step of attaching the support portion to the concave groove of the fixed mold and a step of removing the core by removing the mold after pouring in a state of being arranged in the rim chamber by the support portion. A method of manufacturing a vehicle wheel characterized by the above.

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