JP2003326904A - Manufacturing method of rim wheel - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing method of a rim wheel capable of high productive manufacturing of a rim wheel which 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 for manufacturing a rim wheel having a plurality of sub air chambers 6 arranged in a circumferential direction with equal spacing, and a communicating part 8 communicating a tire main air chamber and the sub air chambers, wherein the sub air chambers 6 and the communicating part 8 form a Helmholtz resonant absorber, includes the steps of (a) forming a vertical wall 3 as a cover member for the sub air chamber 6, when casting the rim wheel, (b) enlarging the vertical wall 3 outside in a radial direction by roll-forming, (c) folding the enlarged vertical wall 3 to form an upper wall 5 as a cover member, and (d) boring the communicating part 8 in the upper wall 5. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a rim wheel for a vehicle to which a tire is attached. For more information,
The rim wheel, which 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 aiming at reduction.

[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 sub air chamber which is formed between a rim and a lid member arranged radially outside of the rim and which is formed by a pair of side walls provided at both ends in the circumferential direction. A plurality of auxiliary air chambers arranged at equal intervals, and a communication portion that is formed in the lid member and that connects the tire main air chamber and the auxiliary air chamber, and the auxiliary air chamber and the communication. When manufacturing a rim wheel that constitutes a Helmholtz resonance sound absorber with the parts, (a) a step of molding a vertical wall as a lid member of the auxiliary air chamber during rim wheel casting, and (b) roll forming the vertical wall. And the step of stretching it radially outward by
(C) A rim wheel including: a step of bending the stretched vertical wall to form an upper wall as a lid member; and (d) a step of boring the communication portion in the upper wall. Is a manufacturing method.

<2> In the method for manufacturing a rim wheel according to <1> above, in the step (a), a side wall is molded together with the vertical wall at the time of casting the rim wheel.

<3> The method for manufacturing a rim wheel according to <1> above, further comprising a step of welding or adhering a side wall to the outer peripheral surface of the rim before the step (c).

<4> A method for manufacturing a rim wheel according to any one of the above <1> to <3>, including a step of welding an end portion of the upper wall to a bead seat of the rim wheel. .

<5> The method for manufacturing a rim wheel according to any one of <1> to <4>, wherein the auxiliary air chamber is provided in three or more chambers.

<6> In the method for manufacturing a rim wheel according to any one of the above <1> to <5>, a rim in which a communicating portion is formed in the upper wall at substantially the center of the circumferential length between the pair of side walls. It is a wheel manufacturing method.

In the rim wheel manufactured by the method of the invention <1>, 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 for forming the sub air chamber, a method of connecting it as a separate member by welding or the like has been conceived and implemented so far, but in the manufacturing method of the present invention described in <1> above, the sub air chamber is Since the vertical wall for forming the lid member is provided on the outer peripheral surface of the rim during casting and is narrowed down to the shape of the sub air chamber by roll forming, the joining work such as welding can be omitted. Therefore, it is possible to prevent a failure due to a welding defect or the like.

In the manufacturing method of <2> of the present invention, since the side wall is formed together with the vertical wall at the time of casting the rim wheel, the step for installing the side wall can be omitted, and when the side wall is installed only by welding. Compared with, it is possible to prevent a failure due to a welding defect or the like.

In the manufacturing method of <3> of the present invention, the side wall is formed by welding. Even in the auxiliary air chamber thus formed, effective reduction of cavity resonance noise is achieved according to the above formula. can do.

In the manufacturing method of <4> of the present invention, by welding the end portion of the upper wall to the bead seat of the rim wheel, a sub air chamber having a high airtightness can be obtained. Cavity resonance noise reduction can be achieved.

In the manufacturing method of <5> of the present invention, since the auxiliary air chamber is formed in three or more air chambers in the circumferential direction by the three or more airtight side walls, there is no resonance sound absorption delay, and the tire does not lag. The cavity resonance sound can be effectively reduced. Preferably, the number of sub air chambers is 4 or more, more preferably 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.

[0021]

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 FIG.

First, in the first manufacturing step (a),
As shown in FIG. 1 (a), the rim 2 is used as a lid member arranged on the outer side in the radial direction of the rim 2 when the rim wheel 1 is cast.
The vertical wall 3 is molded in the upper circumferential direction of the outer peripheral surface of the. Rim wheel 1
When the vertical wall 3 is integrally molded with the rim 2 at the time of casting, the conventional casting method can be applied as it is.

In the illustrated preferred embodiment, the rim wheel body is provided with a recessed 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 that 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 auxiliary air chamber 6 (see FIG. 2) can be obtained while widening the well portion 7. However, from the viewpoint of ensuring a larger volume, it is preferable to make it deeper inward in the radial direction.

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.

Next, in the step (b), the vertical wall 3 is
As shown by the broken line in FIG. 1 (a), it is stretched radially outward by roll forming. The roll forming device (not shown) itself does not have to be a special one, and it is not particularly limited together with the conditions as long as the vertical wall 3 can be narrowed radially outward and stretched. .

The length of the vertical wall 3 in the radial direction is the stepped portion in which the upper wall 5 whose upper end is formed in the next step is formed on the bead seat 4 on the back side of the rim 2 (on the side of the arrow IN). It may be appropriately determined so that it can be engaged with 4A.

Next, in step (c), FIG.
As shown in FIG. 5, the stretched vertical wall 3 is bent to form the upper wall 5 as a lid member. In the illustrated example, it is bent at a substantially right angle, but it may be bent, and in any case, a desired volume can be secured as the sub air chamber 6. Upper wall 5
Although the auxiliary air chamber 6 having high airtightness can be obtained by welding the end portion of the rim wheel to the rim wheel, if the airtightness can be maintained, welding is not particularly necessary. Further, a method other than welding, for example,
It may be fixed by adhesion. 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.

Next, in step (d), the upper wall 5 is provided with a 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. .

Although not shown in the process chart shown in FIG.
The side walls 9 formed at both ends in the circumferential direction of the sub air chamber 6 are preferably molded together with the vertical wall 3 at the time of casting the rim wheel. 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.

Rim wheel 1 manufactured according to the above process
Are shown in FIGS. As shown in FIGS.
Extends between the rim 2, a vertical wall 3 formed in the circumferential direction on the outer peripheral surface of the rim 2, and a bead seat 4 (on the side of the arrow IN direction) from the radially outer end of the vertical wall 3. Existing upper wall 5,
A pair of side walls 9 provided at both ends of the upper wall 5 in the circumferential direction.
It is formed by and. In the present embodiment, the side walls 9 are provided at equal intervals in the circumferential direction, so that the side walls 9 are shared between the adjacent sub air chambers, and the five sub air chambers 6 are arranged.

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. One communication portion 8 is formed for each sub air chamber 6, and the sub air chamber 6 is communicated with 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 with respect to 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.

Rim wheel (6JJ15) of this embodiment
The volume of the tire main air chamber 11 when the tire (195 / 55R15) 10 was mounted on the No. 1 was about 22000 cm ³ , and the total volume of the five auxiliary air chambers 6 was 1500 cm ³ (300
cm ³ × 5), and the total volume of the five auxiliary air chambers 6 is 6.9% of the total volume of the tire main air chamber 11.

[0037]

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: A 6JJ15 ordinary aluminum wheel fitted with a 195 / 55R15 size ordinary passenger car tire.

Example: A rim wheel (5 side walls) having the structure shown in FIGS. 2 to 4 was fitted with passenger car tires similar to the control product.

The relative volume of about 22000Cm ³ of the tire main air chamber, the total volume of the additional air chamber is 1500 cm ³ (6.9% of the tire main air chamber), the diameter of the communication hole 0.8 cm, the communicating hole The length is 0.2 cm.

The resonance frequency of each of the examples and comparative examples was set to about 250 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 3920 N (400 kgf) and the drum axial force in each direction when traveling 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 8.
It was reduced by 7 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 ride comfort test.

Regarding driving 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.

[0045]

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 a process drawing showing a method for manufacturing a rim wheel according to an embodiment of the present invention.

FIG. 2 is a sectional view taken along the axis of rotation showing a main part of a rim wheel manufactured according to the present invention.

FIG. 3 is a side view of the rim wheel shown in FIG. 2 viewed from a direction perpendicular to an axis.

4 is a sectional view taken along the line AA shown in FIG.

[Explanation of symbols]

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

Claims (6)

[Claims] 1. An auxiliary air chamber formed between a rim and a lid member arranged radially outside of the rim, the auxiliary air chamber being formed by a pair of side walls provided at both ends in the circumferential direction. A plurality of auxiliary air chambers arranged at equal intervals, and a communication portion that is formed in the lid member and that connects the tire main air chamber and the auxiliary air chamber, the auxiliary air chamber and the communication portion. When manufacturing a rim wheel that composes a Helmholtz resonance sound absorber with
(A) A step of molding a vertical wall as a lid member of the auxiliary air chamber during casting of a rim wheel, (b) a step of radially extending the vertical wall outward by roll forming, (c)
A method for manufacturing a rim wheel, comprising: a step of bending the stretched vertical wall to form an upper wall as a lid member; and (d) a step of boring the communication portion in the upper wall. . 2. The method for manufacturing a rim wheel according to claim 1, wherein the step (a) includes a step of molding a side wall together with the vertical wall at the time of casting a rim wheel. 3. The method for manufacturing a rim wheel according to claim 1, further comprising a step of welding or adhering a side wall to the outer peripheral surface of the rim before the step (c). 4. The method of manufacturing a rim wheel according to claim 1, further comprising the step of welding an end portion of the upper wall to a bead seat of the rim wheel. 5. The one or more auxiliary air chambers are provided.
4. The method for manufacturing a rim wheel according to claim 4. 6. 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 between the pair of side walls.