JP2003326906A - Manufacturing method of rim wheel - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method capable of high productive manufacturing of a rim wheel suppresses vibrations transmitted to a car, improves a riding quality, reduces noises inside the car, and reduces possible causes of a failure such as defective welding, while assuring a high maneuvering stability. <P>SOLUTION: The method of manufacturing a rim wheel having a plurality of sub air chambers and a connecting part, forming a Helmholtz resonant absorber, comprises the steps of (a) forming an upper wall 3 as well as a bottom part of a rim 2 when casting the rim wheel, (b) welding or adhering a vertical wall between the upper wall 3 and the bottom part of the rim 2, and (c) boring the communicating part in the upper wall 3. A side wall is also formed while casting the rim wheel when the bottom part of the rim 2 and the upper wall 3 are formed. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a method for manufacturing a rim wheel for a vehicle to which a tire is attached. Specifically, the rim wheel that can suppress the vibration transmitted to the vehicle while ensuring high steering stability, improve the riding comfort, reduce the noise in the vehicle, etc. The present invention relates to a manufacturing method for reducing the cause of failure.

[0002]

2. Description of the Related Art In recent years, particularly in high-end vehicles, high functionality has been advanced, which is capable of achieving a high level of driving stability, riding comfort and quietness of an automobile. Under such a request, in order to suppress the tire cavity resonance noise, which is a major factor for the vehicle interior noise, a sub air chamber is provided in the rim wheel, and the Helmholtz resonance is adjusted by adjusting the dimensions of the sub air chamber and the communication hole. Techniques for acting as a sound absorber are disclosed in Japanese Utility Model Laid-Open No. 1-30393, Japanese Utility Model Laid-Open No. 1-90601, Japanese Unexamined Patent Publication No. 1-1115701, Japanese Unexamined Patent Publication No. 1-115702, and European Patent No. 0936083.

However, the technique described in the above-mentioned publicly known document utilizing the action of the Helmholtz resonance sound absorber does not always have a sufficient improvement effect or has some problems, and is still in practical use. The current situation is that it has not arrived.

Under such a circumstance, the rim is formed between the rim and a plurality of lid members arranged radially outside the rim,
By configuring a Helmholtz resonance sound absorber with a plurality of sub air chambers divided by a plurality of side walls provided at intervals in the circumferential direction, and a communication portion that communicates the sub air chambers with the tire main air chamber. It was found that the riding comfort and quietness, which are great performance requirements for automobiles, were significantly improved and a practical rim wheel was obtained, and the applicant of the present invention filed a patent application (Japanese Patent Laid-Open No. 2002-2002). No. 079802).

[0005]

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention
In the rim wheel described in Japanese Patent Publication No. 79802, compared with the conventional technology for configuring the Helmholtz resonance sound absorber,
It is extremely excellent in quietness, steering stability and vibration riding comfort, and can be sufficiently put to practical use. Therefore, it is required to reliably and highly productively manufacture the rim wheel having the sub air chamber as disclosed in the publication.

In view of the above, it is an object of the present invention to suppress vibrations transmitted to the vehicle while ensuring high steering stability, improve riding comfort, reduce vehicle interior noise, etc. It is an object of the present invention to provide a method capable of manufacturing a rim wheel with reduced causes of failure due to defects and the like with high productivity.

[0007]

As a result of intensive studies to solve the above-mentioned problems, the present inventor has found that the above-mentioned object can be achieved by the following constitution, and has completed the present invention. . That is, the present invention is as shown below.

<1> A rim bottom portion, an upper wall arranged radially outside the rim bottom portion, a vertical wall formed between axial end portions of the upper wall and the rim bottom portion, and in a circumferential direction. A plurality of side air chambers divided by a plurality of side walls provided at equal intervals, a tire main air chamber and the auxiliary air chamber, and a communication portion formed in the upper wall, In manufacturing a rim wheel that constitutes a Helmholtz resonance sound absorber with the sub air chamber and the communication part, (a) at the time of casting the rim wheel,
Molding the upper wall with the rim bottom,
(B) a step of welding or adhering a vertical wall between axial end portions of the upper wall and the rim bottom portion, and (c) a step of boring the communication portion in the upper wall. This is a method for manufacturing a characteristic rim wheel.

<2> In the method for manufacturing a rim wheel according to <1> above, in the step (a), when the rim wheel is cast, the sidewall is molded together with the rim bottom and the upper wall. is there.

<3> In the method for manufacturing a rim wheel according to <1> or <2>, after the step (a), the shaft of the upper wall and / or the outer peripheral surface of the axial end of the rim bottom is formed. Including a step (d) of forming an annular groove on the inner peripheral surface of the end portion in the direction, and instead of the step (b), a step (e) of inserting and fixing a split ring-shaped vertical wall into the groove. It is a manufacturing method of a rim wheel including.

<4> In the method of manufacturing a rim wheel according to <3> above, in the step (e), instead of the ring-shaped vertical wall, a vertical wall of a C ring is fitted and fixed in the groove. It is a manufacturing method.

<5> The method for manufacturing a rim wheel according to <3> or <4>, wherein the radial end surface of the vertical wall is covered with rubber.

<6> The method for manufacturing a rim wheel according to any one of the above <1> to <5>, wherein the auxiliary air chamber is provided in three or more chambers.

<7> In the method for manufacturing a rim wheel according to any one of the above <1> to <6>, a rim wheel having a communicating portion formed in the upper wall at substantially the center of the circumferential length of the sub air chamber. Is a manufacturing method.

In the rim wheel manufactured by the method of the present invention described in <1> above, the formed sub air chamber has a communicating portion with the tire main air chamber and functions as a Helmholtz resonance sound absorber. Each dimension such as the volume of the sub air chamber, the cross-sectional area and the length of the communication part is calculated by the following formula, f ₀ : Resonance frequency (Hz) V: Secondary air chamber volume (cm ³ ) S: Total cross-sectional area of communication part (cm ² ) L: Length of communication part (cm) N: Number of communication parts / Air chamber R: Wheel diameter ( Inch), it is possible to achieve effective cavity resonance noise reduction. That is, the rim diameter is first determined, and then the auxiliary air chamber volume V (cm ³ ) and the total cross-sectional area S (c) of the communicating portion are determined.
By determining m ² ), the communicating portion length L (cm), and the number of communicating portions N, it is possible to obtain a rim wheel that can effectively reduce the tire cavity resonance noise. Here, the left term of the above equation represents the Helmholtz resonance frequency. The cavity resonance frequency in the tire main air chamber is determined by the circumferential lengths of the tire and the rim. The frequency is high for tires with a small diameter and low for tires with a large diameter. The right term of the above formula is for obtaining the optimum set frequency range according to the tire size and the rim diameter.

Further, as a method of forming the sub air chamber, a method of connecting it by another member such as welding has been conceived and implemented so far, but in the manufacturing method of the present invention <1>, the side surface of the rim wheel is cast. By providing the cutout, the rim bottom and the upper wall forming the lid of the auxiliary air chamber are manufactured by casting, and the number of members that need to be welded is minimized. As a result, the joining work such as welding can be largely omitted as compared with the past, and failure due to welding defects or the like can be prevented.

In the manufacturing method of <2> of the present invention, since the side wall can be molded together with the vertical wall at the time of casting the rim wheel, the step of installing the side wall can be omitted, and the side wall can be formed only by welding. It is possible to prevent breakdown due to welding defects and the like as compared with the case of installing.

In the manufacturing method of <3> of the present invention, since the auxiliary air chamber is formed by fitting the ring-shaped vertical wall into the groove, the welding for forming the vertical wall can be omitted, which is advantageous in manufacturing. It is advantageous. However, after the vertical wall is fitted in the groove, welding may be further performed to more firmly fix the vertical wall.

In the manufacturing method of <4> of the present invention, the vertical wall is fitted into the groove as a C ring, so that the vertical wall is firmly fixed by its elastic force.

In the manufacturing method of <5> of the present invention, the airtightness of the sub air chamber is enhanced by the action of the covered rubber, and at the same time, the vertical wall is firmly fixed by its elastic force.

In the manufacturing method of <6> of the present invention, since the auxiliary air chamber is circumferentially discontinuously formed into three or more air chambers by three or more closed side walls, resonance absorption delay does not occur. The tire cavity resonance noise can be effectively reduced. Preferably, the number of sub air chambers is 4 or more,
More preferably, the number of rooms is 5 or more.

By drilling the communicating portion by the manufacturing method of the present invention <6>, it is possible to effectively reduce the cavity resonance noise according to the above formula. The number of communicating portions is not limited to one for each sub air chamber, and the resonance frequency setting can be changed only by adjusting the diameter and number of communicating portions. The diameter may be appropriately determined according to the tire size.

[0023]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be specifically described below. A method of manufacturing the aluminum rim wheel 1 according to the embodiment of the present invention will be described with reference to FIGS.

First, in the first manufacturing step (a),
When casting the rim wheel 1, a casting is provided in the direction of the arrow as shown in FIG. This allows the bottom wall of the rim 2 and the upper wall 3 to be molded simultaneously and integrally. In this case, the conventional casting method can be applied as it is.

In the illustrated preferred embodiment, the rim wheel body is provided with a concave well portion 7 for dropping the tire bead portion when the tire is mounted. The bottom of the well portion 7 is located inside the bead seat 4 in the tire radial direction.

The well portion 7 can have a structure which is wide in the axial direction or deep in the radial direction as appropriate. Here, the structure deep in the radial direction means that the diameter difference between the bead portion and the wheel base portion is large, and if there is sufficient brake space, the diameter of the wheel base portion can be reduced to increase the diameter difference. However, if there is no margin, the diameter of the bead portion can be increased to reduce the tire height (same tire outer diameter), or the so-called inch-up method can be used to increase the diameter difference.

Since there is no substantial restriction on widening the well portion 7 in the axial direction, the desired volume of the sub air chamber 6 (see FIG. 2) can be obtained while widening the well portion 7. Although it can be obtained, it is preferable to make it deeper in the radial direction from the viewpoint of ensuring a larger volume.

That is, while forming the well portion 7 on the rim 2,
In order to form the auxiliary air chamber 6 having a desired volume, it is preferable to dispose the vertical wall 3 substantially at the center of the rim 2 in the axial direction. This allows
The tire can be mounted on the rim as usual.

Although not shown in FIG. 1, the side wall 9 formed in the sub air chamber 6 can be molded together with the vertical wall 3 when performing the above-mentioned casting. As a result, the process for installing the side wall can be omitted, and failure due to welding defects or the like can be prevented as compared with the case where the side wall is installed only by welding.

Next, in the step (b), as shown in FIG. 2, a vertical wall 5 is fitted between the axial end portions of the upper wall 3 and the bottom of the rim 2 and then fixed by welding or bonding. . As the adhesive used for the adhesion, for example, a modified acrylate-based adhesive (for example, manufactured by Denki Kagaku Kogyo Co., Ltd., trade name Hard Rock) can be used.

The vertical wall 5 may be formed in a ring shape as shown in FIG. 2 and may be fitted between the axial end portions of the upper wall 3 and the bottom portion of the rim 2, but the split ring-shaped vertical wall shown in FIG. It is preferable to use the wall 5A or the C-shaped vertical wall 5B. In this case, after the step (a), as shown in FIG.
It is possible to form an annular groove 2A on the inner peripheral surface of the axial end portion of and to insert and fix the vertical wall 5A or 5B into the groove 2A. After fixing, the vertical wall 5A or 5B may be more firmly fixed between the axial end portions of the upper wall 3 and the bottom portion of the rim 2 by welding.

When the split ring-shaped vertical wall 5A is used, the individual split vertical walls 5A, which are appropriately divided into four (four in FIG. 4), are fitted into the grooves 2A and fixed by welding or adhesion. You can do it. Also, the C-shaped vertical wall 5
When B is used, both ends of the C ring 5B are brought close to each other by utilizing the recesses a provided near both ends of the C ring 5B, so that the C ring 5B is fitted into the groove 2A and fixed. After fixing, C
The top 5C is fitted into the gap formed between both ends of the ring 5B. The top 5C may be fixed by welding or, although not shown, a screw hole may be provided in the side wall 9 on the rear surface and a screw may be used for screwing.

Further, although not shown, by covering the radial end surfaces of the ring-shaped vertical walls 5A and C-rings 5B with rubber, the airtightness of the sub air chamber can be increased and at the same time, its elasticity can be improved. The vertical wall can be firmly formed by the force.

Next, in the step (c), the upper wall 5 is provided with the communicating portion 8. The means for piercing the communicating portion 8 is not particularly limited, and it is bored to a desired diameter with a drill or the like. In the illustrated preferred example, from the viewpoint that it is preferable to achieve effective reduction of the cavity resonance sound, the communication portion 8 is formed in the upper wall 5 substantially at the center in the circumferential length of the sub air chamber 6. .

Rim wheel 1 manufactured according to the above process
Is shown in FIGS. 5 and 6. As shown in FIGS. 5 and 6, the auxiliary air chamber 6 includes a bottom portion of the rim 2, an upper wall 3, and a vertical wall 5.
And a plurality of side walls 9 provided at equal intervals in the circumferential direction. In this embodiment, five auxiliary air chambers 6 are arranged at equal intervals in the circumferential direction.

In this rim wheel 1, the tire 1
By mounting 0 on the rim 2 of the rim wheel 1, a closed tire main air chamber 11 is formed between the tire 10 and the rim 2. A communication portion 8 is formed for each sub air chamber 6, and the sub air chamber 6 is connected to the tire main air chamber 11 via the communication portion 8. In the present embodiment, the auxiliary air chamber 6 and the communication portion 8 constitute a Helmholtz resonance sound absorber.

Here, when the tire 10 is assembled to the rim wheel 1, each part is set so as to satisfy the above expression. The cavity resonance frequency in the tire main air chamber is determined by the circumference of the tire and the rim, and is 2 for a typical passenger car tire.
The cavity resonance frequency is around 50 Hz. This frequency is high for light vehicle tires and low for large truck tires.

The total inner volume of the sub air chamber 6 for one rim wheel 1 is preferably 2% or more and 25% or less of the volume of the tire main air chamber 11, and more preferably 3% or more 15
% Or less is more preferable.

The rim wheel of the present embodiment (7 1 / 2J
J × 17) 10 with tire (225 / 55R17) 14
The volume of the tire main air chamber 11 when installed is about 35,000.
cm ³And the total volume of the five auxiliary air chambers 6 is 1880 cm³
(470 cm³X 4), and the total of the 5 auxiliary air chambers 6
The product is 5.4% of the total volume of the tire main air chamber 11.

[0040]

EXAMPLES The present invention will be described below based on examples. Conventional rim wheel and tire combination product (comparative example)
And a combination product (Example) of a rim wheel to which the present invention was applied and a tire were prototyped, and a road noise evaluation drum test was performed.

Control product: 7 1/2 JJ × 17 normal aluminum wheels fitted with 225 / 55R17 size normal passenger car tires.

Example: A rim wheel (five side walls) having the structure shown in FIG. 5 was fitted with passenger car tires similar to the control product.

The total volume of the sub air chamber was 1880 cm ³ (5.4% of the tire main air chamber), while the volume of the tire main air chamber was about 35,000 cm ³ , and the diameter of the communication hole was 0.9 cm and the diameter of the communication hole was 0.9 cm. The length is 0.25 cm.

The resonance frequency of each of the examples and comparative examples was set to about 210 Hz according to the above formula. The road noise drum has a diameter of 3 m, and asphalt imitating a general road shape is attached to the surface. The tire was pressed against the drum with a load of 4900 N (500 kgf) and the drum axial force in each direction when running at a speed of 60 km / h was measured and frequency analysis was performed.

As a result of the frequency analysis of the axial force in the vertical direction, the cavity resonance peak in the example is about 1 as compared with the comparative example.
It was reduced by 2.6 dB.

Further, the tires of Examples and Comparative Examples were mounted on a passenger car, and two test drivers performed actual vehicle running on a test course to conduct a steering stability test and a vibration riding comfort test.

With respect to steering stability, driveability, braking performance,
Comprehensive evaluation of steering wheel responsiveness and controllability at the time of control, and for vibration ride comfort test, comprehensive evaluation of vibrations during running on good roads, vibrations during running on bad roads, vibrations during running on special roads such as steps, and noise inside the vehicle The tires of the examples were evaluated by an index when (Comparative example) was set to 100. The larger the index number, the better. The result of the example shows that the steering stability is 1
10, the vibration riding comfort was 115, and the vehicle interior noise was 155.

[0048]

As described above, according to the present invention, it is possible to suppress vibrations transmitted to the vehicle while ensuring high steering stability, improve riding comfort, and reduce noise in the vehicle. It is possible to manufacture a rim wheel with reduced causes of failure due to welding defects and the like with high productivity.

[Brief description of drawings]

FIG. 1 is an explanatory view showing a method for manufacturing a rim wheel according to an embodiment of the present invention.

FIG. 2 is an explanatory diagram showing a method of manufacturing a rim wheel according to an embodiment of the present invention.

FIG. 3 is an enlarged cross-sectional view showing a vertical wall portion.

FIG. 4 is an explanatory diagram showing a method of manufacturing a rim wheel according to an embodiment of the present invention.

FIG. 5 is a cross-sectional view taken along the rotation axis showing a main part of a rim wheel manufactured according to the present invention.

6 is a side view of the rim wheel shown in FIG. 5 as seen from a direction perpendicular to the axis.

[Explanation of symbols]

1 rim wheel 2 rims 3 Upper wall 4 bead seat 5,5A, 5B Vertical wall 6 Sub air chamber 7 well part 8 communication parts 9 Side wall 10 tires 11 Main chamber

Claims (7)

[Claims] 1. A rim bottom, an upper wall arranged radially outside the rim bottom, a vertical wall formed between axial ends of the upper wall and the rim bottom, circumferentially equidistantly, and the like. A plurality of side air chambers divided by a plurality of side walls provided at intervals; and a communication portion, which communicates with the tire main air chamber and the sub air chamber and is formed in the upper wall, In manufacturing a rim wheel that constitutes a Helmholtz resonance sound absorber with the air chamber and the communication part, (a) molding the upper wall together with the rim bottom part during casting of the rim wheel, and (b) the upper wall And a step of welding or adhering a vertical wall between axial end portions of the rim bottom portion and the rim bottom portion, and (c) a step of drilling the communication portion in the upper wall. Production method. 2. The method of manufacturing a rim wheel according to claim 1, wherein in the step (a), the side wall is molded together with the rim bottom and the upper wall when the rim wheel is cast. 3. After the step (a), a step of forming an annular groove on the outer peripheral surface of the axial end of the rim bottom and / or on the inner peripheral surface of the axial end of the upper wall ( The method for manufacturing a rim wheel according to claim 1 or 2, further comprising a step (d), which includes a step (e) in which a split ring-shaped vertical wall is fitted and fixed in the groove instead of the step (b). 4. The method of manufacturing a rim wheel according to claim 3, wherein in the step (e), a vertical wall of a C ring is fitted in and fixed to the groove instead of the vertical wall of the ring shape. 5. The method of manufacturing a rim wheel according to claim 3, wherein the radial end surface of the vertical wall is covered with rubber. 6. The one or more auxiliary air chambers are provided.
5. The method for manufacturing a rim wheel according to claim 5. 7. The method of manufacturing a rim wheel according to claim 1, wherein a communication portion is provided in the upper wall at a substantially central portion of a circumferential length of the sub air chamber.