JP2010100121A - Wheel for automobile and method for manufacturing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a wheel having a counter balance with superior run-out accuracy. <P>SOLUTION: The wheel 10 for automobile includesa disk 7 to be press-fitted to the inside of a rim trimming 8. The disk 7 includes four flanges 3a-3d and four disk material reductions 4a-4d. An air valve is fitted to a valve hole 9 of the rim 8. One disk material reduction is present at the position corresponding to the valve hole 9. The counter balance mass for the mass of the air valve can be easily ensured by setting the length of two flanges 3a, 3d for holding the disk material reduction on the opposing side of the disk material reduction to be larger than the length of the other two flanges 3b, 3c. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an automobile wheel and a method for manufacturing the same.

  2. Description of the Related Art In recent years, tire pressure alarm systems have been attached to automobile wheels for the purpose of detecting the pressure in the tire and preventing accidents. The tire pressure alarm system includes a direct tire pressure alarm system (referred to as “TPMS”) that directly detects tire pressure using an air valve with a built-in tire pressure sensor, and a relative tire pressure by detecting ABS wheel speed. Although an indirect tire pressure warning system for estimating the tire pressure is known, since a detection accuracy is excellent, a direct tire pressure warning system is generally used.

  However, if an air valve with a tire pressure sensor is attached to a normal wheel as it is, the center of gravity of the wheel is biased toward the air valve, increasing the unbalanced amount of the wheel. To prevent this, the mass of the air valve with the tire pressure sensor is molded to the disc in advance so that it is unbalanced, and the light valve trimming air valve mounting hole of the molded disc is aligned and welded in the circumferential direction. Is manufactured. Consideration is given to ensuring proper wheel balance when an air valve with a tire pressure sensor is installed.

  1A and 1B are diagrams for explaining a general disk forming process, where FIG. 1A is a state after a blanking step, FIG. 1B is a state after a drawing step, hub hole punching / trimming step, and FIG. Shows the state after flange-up, (d) shows the state after various holes are removed, and (e) shows the state after coining. In each figure, a top view is shown above, and a sectional view is shown below. Each is listed.

  In the disk forming process, the plate unwound from the material coil is cut into a predetermined dimension, and then, in the blanking process, the four corners are cut into arcs as shown in FIG. obtain. Next, drawing is performed in a state where the arc-shaped four corners of the blank 1 are clamped (usually, a drawing process of 2 to 4 steps), and thereafter, as shown in FIG. At the same time, the four flanges 3a to 3d are trimmed so as to have a predetermined shape. At this time, the lengths of the flanges 3a to 3d are cut so as to be constant, and four disk thefts 4a to 4d are formed.

  Thereafter, as shown in FIG. 1 (c), the flanges 3a to 3d are raised by the flange-up process. Further, as shown in FIG. 1 (d), the bolt holes 5 and the cooling holes 6 are removed. Then, as shown in FIG. 1E, the cooling holes 5 and the bolt holes 6 are coined to complete the disc. At this time, the disk stealing shape and depth are almost the same at all four locations, and consideration is given to minimizing the influence on wheel runout. And the flange of the disk formed in this way is joined with the inner surface side of a rim, and a wheel is manufactured.

  In the invention described in Patent Document 1, instead of continuously cutting the wire while rewinding the coil, blanking is performed while the coil is flowing, and a mass increasing portion is formed in the disk light portion and the facing portion. .

  In the example shown in Patent Document 2, for example, in the example shown in FIGS. 3 and 4, after the coil is unwound and cut, the arc-shaped blank dimension in the next blank process is increased or decreased at one place and cut out. A mark is put on the part that became a light part. Moreover, in the example shown in FIG. 5, a light part is formed by punching holes at one place blanked in an arc shape.

  In the invention described in Patent Document 3, a notch portion in which the disc flange height (foot length) is shortened is provided in the disc stealing coinciding with the rim air valve in order to form the disc light portion. In addition, the length of the welded part closest to the rim air valve is reduced to create an unbalance to balance the air valve.

JP 2005-8049 A JP 2002-166703 A Japanese Utility Model Publication No. 3-5601

  The method described in the cited document 1 has a problem that the blade shape of blanking is complicated and the life of the blade is shortened, and that the disk continuous forming machine (transfer device) needs to be significantly modified. In addition, the mold shape is complicated, resulting in a significant cost increase. Further, since the shape of the disk stealing is irregular (unstable), the wobbling property at the completion of the wheel becomes a big problem.

  The method described in the cited document 2 requires, for example, processing in FIG. 5, a separate process (notch, hole punching), and thus increases the number of processes. Moreover, as shown in FIG. 6, the pre-made disc light part and the air valve position do not completely match, so the unbalance adjustment is completely eliminated when the air valve with tire pressure sensor is installed. Can not.

  In the method of the cited document 3, in order to form the light part by the notch, a punching process must be added after the disk flange starting process described above. In addition, this process requires a very complicated mold and is expected to reduce the tool life and increase the lateral and longitudinal runout of the wheel after assembly welding. In addition, the formation of the light part by the welding length makes it difficult to secure the balance because the light part mass is insufficient when the tire pressure sensor is mounted. Usually, the mass of an air valve with a tire pressure sensor is about 38 g to 40 g, and it is almost impossible to secure a balance by forming a light part only with a weld length.

  As described above, according to the invention disclosed in the above publication, problems remain, such as coil shear cutting and complicated molding dies when manufacturing a disk. In addition, in order to cope with recent TPMS mounting, a manufacturing method and a processing method in which an unbalance amount sufficient to offset the TPMS mass is ensured and wheel runout and cost are taken into consideration are important.

  The present invention has been made to solve the above-described problems of the prior art, and is intended for automobiles that can easily adjust the mass balance without reducing the production efficiency of the disk manufacturing process trimming and disk assembly process. It aims at providing a wheel and its manufacturing method.

As a result of intensive studies to solve the above problems, the present inventor has obtained the following knowledge.
As already described, the arc-shaped four corner portions formed in the blanking process finally become flanges. In other words, drawing is performed with the arc-shaped four corners clamped, and then cut into the required length at the time of hub drilling / trimming process, and then raised to a flange shape in the subsequent flange-up process. It becomes a flange.

  That is, since the flange portion is a portion to be clamped in the drawing process, it is necessary to ensure a sufficient length in the drawing process, but in the subsequent processes, the length required for joining to the rim is not enough. Since it is sufficient, it is cut into a predetermined length in the hub hole punching / trimming process. At this time, it has been found that by adjusting the length of the flange, it is possible to easily secure the counterbalance mass corresponding to the mass of the air valve with the pressure sensor.

  The present invention has been made on the basis of such knowledge, and the gist of the present invention is the automobile wheel shown in the following (1) and the manufacturing method of the automobile wheel shown in the following (2) and (3).

  (1) An automobile wheel having a disk press-fitted inside the rim trimming, wherein the disk has four flanges and four disk steals, and the lengths of two adjacent flanges are different from each other. An automobile wheel characterized by being longer than the length of two adjacent flanges.

  (2) A punching process for punching a steel plate for a disk to obtain a blank, a drawing process for processing a disk into a disk shape with the four flanges of the blank clamped, a trimming process for cutting off the flange of the disk molded body, a disk An automobile wheel manufacturing method for manufacturing a disk by a process including a smoothing process for raising a flange of a molded body and a hole punching process for forming a hole in the disk molded body, wherein two adjacent flanges ( A method for manufacturing an automobile wheel, characterized in that the length of the first flange pair) is cut so as to be shorter than the length of the other two adjacent flanges (second flange pair).

(3) In the trimming step, the first flange pair and the second flange pair are cut so that an A value obtained from the following equation (1) is in a range of 20.46 to 23.54. The manufacturing method of the wheel for motor vehicles of (1).
A = 1.03K _bd + 3.42t−0.29T _bg −U _bd (1)
However, the meaning of each symbol in the above formula (1) is as follows.
K _bd : Flange trimming diameter of the first flange pair (mm)
U _bd : Flange trimming diameter of the second flange pair (mm)
T _bg : Mass of air valve with pressure sensor (g)
t: Thickness of disk material (mm)

  According to the present invention, the counter balance amount when the air valve with pressure sensor is mounted can be reflected in the product design. In addition, it is possible to provide a wheel with a counter balance that has good runout accuracy without significantly modifying the disk forming machine.

  FIG. 2 is a diagram showing an example of an automobile wheel in which a disk and a rim are joined. FIG. 3 is a diagram showing the form of the disc flanges having different lengths, and FIG. 4 is a diagram showing the disc shape after the hub hole punching / trimming process.

  As shown in FIG. 2, the automobile wheel 10 of the present invention includes a disk 7 that is press-fitted and fitted inside a rim 8 trimming 8. As shown in FIGS. 1 to 3, the disk 7 has four flanges 3a to 3d and four disk thefts 4a to 4d. An air valve (not shown) is attached to the valve hole 9 of the rim 8. One disk stealing (for example, 4a in FIG. 1) exists at a position corresponding to the valve hole 9. Then, the length of two flanges (for example, 3b and 3c in FIGS. 1 and 3) sandwiching the disk theft (for example, 4c in FIG. 1) on the opposite side of this disk theft is set to the other two flanges (for example, By making it longer than the lengths 3a and 3d) in FIGS. 1 and 3, it is possible to easily secure the counterbalance mass corresponding to the mass of the air valve.

  Here, the manufacturing method of the disk is not particularly limited. For example, as shown in FIG. 1, a punching process for punching a steel sheet for a disk to obtain a blank, and a disk shape with four flanges clamped. The disk is manufactured by a process including a drawing process to obtain a disk molded body, a trimming process for cutting off the flange of the disk molded body, a smoothing process for raising the flange of the disk molded body, and a punching process for forming a hole in the disk molded body. Can be manufactured.

  That is, in the disk forming process, the plate unwound from the material coil is cut to a predetermined size, and then, in the blanking process, the four corners are cut into arcs as shown in FIG. Get one. Next, drawing is performed in a state where the arc-shaped four corners of the blank 1 are clamped (usually, a drawing process of 2 to 4 steps), and thereafter, as shown in FIG. At the same time, the four flanges 3a to 3d are trimmed so as to have a predetermined shape. At this time, the lengths of the flanges 3a to 3d are cut so as to be constant, and four disk thefts 4a to 4d are formed.

  Thereafter, as shown in FIG. 1 (c), the flanges 3a to 3d are raised by the flange-up process. Further, as shown in FIG. 1 (d), the bolt holes 5 and the cooling holes 6 are removed. Then, as shown in FIG. 1E, the cooling holes 5 and the bolt holes 6 are coined to complete the disc. At this time, the disk stealing shape and depth are almost the same at all four locations, and consideration is given to minimizing the influence on wheel runout. And the flange of the disk formed in this way is joined with the inner surface side of a rim, and a wheel is manufactured.

  Here, generally, when the size of the wheel is determined, a disk blank calculation is performed. This expands the cross-sectional shape of the disk, the coil width and shear cutting length are determined from the input material dimensions, and the angular dimensions are further determined. The round dimension in the next hole punching / trimming process is determined by appropriately judging the length of the disc flange foot that becomes the assembly weld in addition to the inset length of the design dimension.

  There is no particular restriction on the method of adjusting the length of the flange. For example, the length can be adjusted in the blanking process, but the flanges after the blanking (arc-shaped four corners) are locations to be clamped in the drawing process of the subsequent process. rare. Therefore, in the above hole punching / trimming step, for example, as shown in FIG. 4, the length of two adjacent flanges 3a, 3d (trimming diameter) is made longer than the length of the other two adjacent flanges 3b, 3c. It is good to cut so that it may become long.

Here, for example, the trimming diameters of the first flange pair and the second flange pair can be obtained by the following calculation formula.
A = 1.03K _bd + 3.42t−0.29T _bg −U _bd (1)
However, the meaning of each symbol in the above formula (1) is as follows.
K _bd : Flange trimming diameter of the first flange pair (mm)
U _bd : Flange trimming diameter of the second flange pair (mm)
T _bg : Mass of air valve with pressure sensor (g)
t: Thickness of disk material (mm)

  The length of the first flange pair and the second flange pair should be determined and cut so that the A value is in the range of 20.46 to 23.54. When the A value is smaller than 20.46, there is a high probability that the static unbalance after completion of the wheel exceeds 400 g · cm. On the other hand, if it exceeds 23.54, the difference in flange diameter increases, so that the runout accuracy is deteriorated and the productivity may be reduced. In addition, the counter balance amount becomes excessive, and there is a possibility that the static unbalance amount after completion of the wheel becomes large.

  Usually, if the generated stress is known by disc stress analysis or the like, the disc plate thickness is determined, and if the disc size and shape are determined, the angular dimension and disc flange trimming diameter can be determined. In addition to this information, if the mass of the air valve with pressure sensor is known, the counter balance amount required by the disk, that is, the trimming diameters of the first flange pair and the second flange pair can be easily calculated using the above formula. can do.

Here, it is preferable to limit the static unbalance amount to 400 g · cm or less when an air valve with a pressure sensor is attached. The total mass of the air valve with pressure sensor is Tbg, and the diameter of the rim at the valve hole position is Vrd (see FIG. 2). When the counter balance mass of a disk on which one disk light spot (counter balance) is formed is Ung, the disk flange outer diameter is Dfd (see FIG. 2), and the disk plate thickness is t (see FIG. 2), the following formula When the air valve with pressure sensor is installed, the balance of the wheel can be adjusted with high accuracy.
Tbg · Vrd / 2−Ung · (Dfd−t) / 2 ≦ 150
However, the meaning of each symbol in the above formula is as follows.
T _bg : Total mass of air valve with pressure sensor (TPMS mass + valve mass) (g)
V _rd : Diameter (mm) at the valve hole position of the rim
_Ung : counterbalance mass of disk (g)
D _fd : Disc flange outer diameter (mm)
t: thickness of the disk (mm)

  Note that the value on the left side of the above expression corresponds to the unbalance amount Wug of the entire wheel when the air valve with pressure sensor is mounted. The tolerance of cutting, blanking, and trimming dimensions is ± 0.5 mm, and cutting is performed in units of 1 mm. In consideration of manufacturing variations, Wug is preferably 150 or less. When the above formula is satisfied, the unbalance amount of the wheel that has been assembled and welded by disc trimming can be reliably suppressed to 400 g · cm or less.

Here, Ung may be measured after manufacturing the disk, or the following equation may be used for estimation at the design stage.
U _ng = -3.36 · U _bd + 3.47 · K _bd + 11.79 · t-77.7
However, the meaning of each symbol in the above formula is as follows.
_Ung : counterbalance mass of disk (g)
K _bd : Flange trimming diameter of the first flange pair (mm)
U _bd : Flange trimming diameter of the second flange pair (mm)
t: thickness of the disk (mm)

  In addition, there is no restriction | limiting in particular about the method of fitting a disk to a rim, However, It is good to join by welding, and it is preferable to weld all the flanges simultaneously especially. At this time, the welding is welding with each flange tip portion trimming, but it may be 1-bead welding in which each flange is a continuous bead, or may be 8 beads or 12 beads by intermittently welding each flange.

In order to confirm the effect of the present invention, an experiment was carried out in which an air valve with a pressure sensor having a mass (T _bg ) of 39 g was mounted on a 15 inch × 6 J size wheel, and various balances were investigated.

First, after blanking a plate material of 424 mm square obtained by shear cutting with a disc plate thickness of 2.9 mm and a blank round dimension of φ470 mm, drawing was performed, and the first flange pair (the longer flange) Trimming was performed by setting the round dimension (K _bd ) of the flange pair) to φ440 mm.

Product design with valve hole position diameter (V _rd ) of 359.2 mm, disk outer diameter (D _fd ) of 338.4 mm, rim diameter (R _d ) of 380.2 mm, and flange height (F _h ) of 17.5 mm did.

Here, U _bd was determined using the A value obtained from the following equation (1) as the center value.
A = 1.03K _bd + 3.42t−0.29T _bg −U _bd (1)

As a result, the trimming diameter dimension U _bd of the second flange pair (shorter flange pair) in the trimming process is φ429.37 mm, and the counterbalance calculation mass U _ng of the disk obtained from the following equation is 38.88 g. Yes, the counter balance mass was almost the same as the air valve with pressure sensor.
U _ng = -3.36 · U _bd + 3.47 · K _bd + 11.79 · t-77.7

The U _bd when the A value was the Min value was φ431.1 mm, and the Max value was φ428.5 mm.

In actual disk manufacture, in order to make uniform at the time of fitting, φ430 mm, which is a value close to the flange trimming diameter U _bd of the second flange pair obtained with the A value as the center value, was selected. In this case, the actual counterbalance mass (U _ng ) of the disk was 36 g.

Here, the wheel unbalance amount W _ub (g · cm) when the valve was mounted was calculated by the following formula based on the disk counterbalance actual measurement mass U _ng (36 g), which was 96.5.
W _ub = T _bg · V _rd / 2-U _ng · (D _fd −t) / 2

On the other hand, when the wheel unbalance amount W _ub (g · cm) when the valve was mounted was calculated by the above formula based on the counter balance calculated mass U _ng (38.88 g) of the disk, it was 48.3.

W _ub is 150 (g · cm) or less regardless of whether the measured value or the calculated value is U _ng , and it is expected that the static unbalance after the wheel is completed will be good.

  A disk was manufactured under the above conditions and dimensions, and assembly welding was performed by matching the valve hole of a rim of 15 inches × 6 J with one disk steal. The assembly welding was MAG welding, and the disk flange was 70 mm in welding length, and four locations were welded simultaneously. At this time, a target position was determined for each of the welding line position of the first flange pair and the changing welding line position of the second flange pair, and welding was performed.

  After assembly welding, a chemical conversion treatment process and an electrodeposition undercoating process were performed, and after the top coating, the product was dried by a drying process. For 10 completed wheels, the static unbalance amount when the air valve with pressure sensor was not installed was compared with the static unbalance amount when the air valve with pressure sensor was installed. The results are shown in Table 1.

  As shown in Table 1, in the case of a wheel with a counterbalance, when the pressure sensor valve is not attached, the static unbalance amount of the wheel alone is remarkably large. However, by mounting the pressure sensor valve, the unbalance mass was greatly reduced, and the average unbalance amount was 125.5 g · cm, which was significantly below the target of 400 g · cm.

  Further, Table 2 shows the results of measuring the dynamic unbalance amount on the outer side and the inner side by assembling the tire on this wheel.

  As shown in Table 2, the dynamic unbalance amount of the wheel of the present invention was that the unbalance mass was 4.5 g at the maximum on both the outer side and the inner side, and the unbalance amount was about 90 g · cm. Therefore, even when a balancer weight is attached, it is possible to ensure balance with a small weight of about 5 g. From the above results, it was found that according to the present invention, it is possible to provide a wheel with a counterbalance having a high balance.

  Next, the static unbalance amount in the case of a normal wheel is shown in Table 3, and the dynamic unbalance amount is shown in Table 4. In addition, a normal wheel does not provide a diameter difference between Kbd and Ubd.

  As shown in Table 3, the static unbalance amount of a single wheel is less than 400 g · cm at a maximum of about 300 g · cm although there is variation, but when the pressure sensor valve is installed, the unbalance amount is the average 760 g · cm and a maximum of 915 g · cm. Further, as shown in Table 4, when the dynamic balance after the tire ASSY was investigated, the unbalance amount tended to be somewhat small, but the average value and the maximum value were almost equal. It can be seen that the weight mass for balancing needs to be 45 to 50 g at the maximum. This weight mass requires a considerably large size in dimension and does not look good in appearance, and becomes a serious problem even if it falls off during traveling.

  Next, the runout property was examined. In this experiment, the wheel with the counter balance of the present invention (No. 1 to 10), the normal wheel (No. 11 to 20), and the wheel (No. 21 to 30) with a notch in the conventional disk stealing were used. The runout accuracy was measured with a single wheel. For comparison, a runout standard was set, and the case where the range was exceeded was evaluated as NG, and the range was evaluated as OK. The run-out acceptance criteria were set as 0.5 mm or less for the vertical run average, and 0.7 mm or less for the lateral runout outer and inner sides. The results are shown in Table 5.

  A wheel with a notch in a conventional disc stealer is a disc or smear (arch) with a cutout lightweight part, and the notch lightweight part and the mounting position of the pressure sensor valve By combining them, a static unbalance is ensured in a state where the pressure sensor valve is mounted.

  As shown in Table 5, the runout accuracy of the wheels of the present invention (No. 1 to 10) and the normal wheels (No. 11 to 20) is good for both the outer side and inner side vertical runout and lateral runout. Is secured. On the other hand, in the conventional type of wheel stealing (No. 21-30) with a notch, the vertical runout was large and most of them were NG. From these results, it has been found that it is most effective to improve the deflection accuracy by uniformly press-fitting each of the four locations of the disk flange and the disk stealing as much as possible.

  According to the present invention, the counter balance amount when the air valve with pressure sensor is mounted can be reflected in the product design. In addition, it is possible to provide a wheel with a counter balance that has good runout accuracy without significantly modifying the disk forming machine.

Diagram explaining general disk forming process (a) State after blanking step (b) State after drawing step, hub punching / trimming step (c) State after flange up (d) Various holes The state after removal (e) is the state after coining The figure which shows the example of the wheel for cars which joined the disk and the rim Diagram showing the form of disc flanges with different lengths superimposed Diagram showing disk shape after hub drilling / trimming process

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Blank 2 Hub 3a-3d Flange 4a-4d Disc stealing 5 Bolt hole 6 Cooling hole 7 Disc 8 Rim 9 Valve hole 10 Automobile wheel of this invention

Claims (3)

  An automotive wheel having a disc press-fitted inside a rim trimming, wherein the disc has four flanges and four disc steals, and the length of two adjacent flanges An automobile wheel characterized by being longer than the length of two flanges. A punching process for punching a steel plate for a disk to obtain a blank, a drawing process for obtaining a disk molded body by clamping the four flanges of the blank into a disk shape, a trimming process for cutting off the flange of the disk molded body, A method for manufacturing a vehicle wheel for manufacturing a disk by a process including a smoothing process for raising a flange and a hole punching process for forming a hole in a disk molded body,
In the trimming step, an automobile wheel characterized in that the length of two adjacent flanges (first flange pair) is cut to be shorter than the length of the other two adjacent flanges (second flange pair). Manufacturing method. 3. The trimming step, wherein the first flange pair and the second flange pair are cut so that an A value obtained from the following equation (1) falls within a range of 20.46 to 23.54. The manufacturing method of the wheel for motor vehicles of description.
A = 1.03K _bd + 3.42t−0.29T _bg −U _bd (1)
However, the meaning of each symbol in the above formula (1) is as follows.
K _bd : Flange trimming diameter of the first flange pair (mm)
U _bd : Flange trimming diameter of the second flange pair (mm)
T _bg : Mass of air valve with pressure sensor (g)
t: Thickness of disk material (mm)

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