JP5323446B2 - Wheel for automobile and manufacturing method thereof - Google Patents

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, it cut | disconnects so that the leg length of the flanges 3a-3d may become fixed, and the four concave edge parts 4a-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 shape and depth of the concave edge portions are almost the same at all four locations, and consideration is given to keep the influence on the wheel runout to a minimum. 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 at the concave edge portion that matches 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. In addition, since the shape of the concave edge portion is irregular (unstable), the runnability upon 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.

In other words, since the arc-shaped four corners are locations 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 necessary for joining to the rim is required. Therefore, in the hub hole punching / trimming process, it is cut into a predetermined length. At this time, it was found that the counterbalance mass corresponding to the mass of the air valve with the pressure sensor can be easily secured by adjusting the length of the flange portion .

  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) A vehicle wheel comprising a disk to be press-fitted to the inside of the rim trimming disk has four flanges and four concave edge portion, the foot length of two flanges adjacent, An automotive wheel characterized by being longer than the length of the other two adjacent flanges.

(2) A punching process for punching a steel plate for a disk to obtain a blank having arc-shaped four corners, a drawing process for obtaining a disk compact by processing the four corners into a disk shape, and cutting off a part of the four corners And a trimming step for forming the flange pre-determined portion, a flange-up step for raising the pre-flange portion of the disk molded body to form a flange, and a hole manufacturing step for forming a hole in the disk molded body. In the trimming step, the trimming diameter of two adjacent flange planned portions (first flange planned portion pair) is set to the other two adjacent flange planned portions (second flange planned portion pair). automotive wheel, characterized in that to be shorter than trimming the diameter of a step of cutting off a part of the four corners Manufacturing method.

(3) In the trimming step, part of the four corners is cut off so that an A value obtained from the following formula (1) is in a range of 20.46 to 23.54. Method for manufacturing automobile wheels.
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 : Trimming diameter (mm) of the first flange planned portion pair
U _bd : Trimming diameter of the second flange planned portion pair (mm)
T _bg : Mass of air valve with pressure sensor scheduled for installation (g)
t: Thickness of the steel plate for disc (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 disc flanges having different foot lengths , and FIG. 4 is a diagram showing a disc shape after 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. 1 to 3, the disk 7 has four flanges 3a to 3d and four concave edge portions 4a to 4d . An air valve (not shown) is attached to the valve hole 9 of the rim 8. One concave edge (for example, 4a in FIG. 1) exists at a position corresponding to the valve hole 9. The concave edge portion of the facing side of the concave edge portion (e.g., 4c in Figure 1) two flanges sandwiching (e.g., 3b in FIGS. 1 and 3, 3c) feet in length, the other two flanges By making it longer than the foot length (for example, 3a, 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 disc is not particularly limited. For example, as shown in FIG. 1, a blanking process for punching a steel plate for a disc to obtain a blank having four arc-shaped corners . Forming a disk by processing it into a disk shape in a clamped state, a trimming process for cutting off part of the four corners, a flange-up process for forming a flange by raising a predetermined flange portion , and forming a hole in the disk molded body The disc can be manufactured by a process including a hole punching process.

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 pre- flange portions 3a to 3d are cut so that the trimming diameter is constant, and four concave edge portions 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 shape and depth of the concave edge portions are almost the same at all four locations, and consideration is given to keep the influence on the wheel runout to a minimum. 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 limitation on the method of adjusting the leg 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 lengths (trimming diameters) of two adjacent flange planned portions 3a, 3d are set to the other two adjacent flange planned portions 3b, It is good to cut | disconnect so that it may become longer than the length of 3c.

Here, for example, the trimming diameters of the first flange planned portion pair and the second flange planned portion 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: first flange portion to be a pair of trimming diameter (mm)
U _bd: second flange portion to be a pair of trimming diameter (mm)
T _bg : Mass of air valve with pressure sensor (g)
t: Thickness of the steel plate for disc (mm)

It is preferable that the trimming diameters of the first flange predetermined portion pair and the second flange predetermined portion pair are 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, knowing the stress generated by the stress analysis of the disk, it determines a disk plate thickness, once the disk geometry, it is possible to determine the angular dimensions and trimming size. In addition to these information, if you know the air valve mass with pressure sensor, by the above equation, counterbalancing the amount of disk need, i.e., a first flange portion to be paired and trimming the diameter of the second flange portion to be paired Can be easily calculated.

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 the disk (g)
D _fd : Disc flange outer diameter (mm)
t : Disc thickness (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 the disk (g)
K _bd: first flange portion to be a pair of trimming diameter (mm)
U _bd: second flange portion to be a pair of trimming diameter (mm)
t : Disc thickness (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 conducted 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, a disk plate thickness as 2.9 mm, the plate corners 424mm obtained by shear cutting, after blanking a blank round dimensions as Fai470mm, drawing implement, the dish, the first flange portion to be paired (long round the dimensions of the square of the flange portion to be pair) the _{(K bd)} as φ440mm, was trimming.

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, trimming diameter _{U bd} of the second flange portion to be paired with the trimming process (shorter flange portions to be paired) is Fai429.37Mm, counterbalance calculated mass _{U ng} of the disk obtained from the following equation, It was 38.88 g, and the counterbalance mass was almost the same as that of the air valve with a 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 disc production, in order to uniform the time of mating were selected φ430mm a value close to the second flange portion to be a pair of trimming diameter U _bd obtained the A value as the center value. 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 according to the following formula based on the counter balance actual measurement mass U _ng (36 g) of the disk, which was 96.5.
W _ub = T _bg · V _rd / 2-U _ng · (D _fd −t) / 2

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

W _ub are measured values, even when using the calculated value either U _ng, has a 150 (g · cm) or less, the static unbalance amount after wheel completed is expected to be good.

A disk was manufactured under the above conditions and dimensions, and assembly welding was performed by matching a valve hole of a rim of 15 inches × 6 J with one concave edge . The assembly welding was MAG welding, and the disk flange had a welding length of 70 mm and four points were welded simultaneously. At this time, a target position was determined for each of the weld line position of the first flange planned portion pair and the weld line position of the second flange predetermined portion pair that was changed, 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 with a notch in the conventional concave edge (No. 21 to 30) 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.

The conventional wheel with a notch in the concave edge portion is a light-cut portion provided on the disc or the smear portion (arch portion), and the notch light-weight portion and the mounting position of the pressure sensor valve To ensure static imbalance when 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 A side and B side runout and lateral runout. Is secured. On the other hand, in the conventional type of wheel (No. 21 to 30) in which the concave edge portion was notched, the vertical runout was large, and almost no 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 concave edge portion 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 foot lengths superimposed Diagram showing disk shape after hub drilling / trimming process

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

Claims (3)

A vehicle wheel comprising a disk to be press-fitted to the inside of the rim trimming disk has four flanges and four concave edge portion, the foot length of two flanges adjacent, next to the other An automobile wheel characterized by being longer than the leg length of two matching flanges. Punching to obtain a blank having an arcuate corners by punching a steel sheet for disk, stop steps and processed into a disk shape to obtain a disc shaped body clamped the corners, to overlooked off a part of the four corners, the flange A vehicle wheel for manufacturing a disk by a trimming process for forming a planned part , a flange-up process for forming a flange by raising a planned flange part of the disk molded body, and a hole punching process for forming a hole in the disk molded body. A manufacturing method comprising:
In the trimming step, the flange portions to be adjacent two trimming diameter (first flange portion to be paired), to be shorter than trimming the diameter of the two flanges scheduled portion adjacent the other (second flange portion to be paired) the A method for manufacturing a wheel for an automobile, which is a step of cutting off part of the four corners . 3. The automobile wheel according to claim 2, wherein in the trimming step, a part of the four corners is cut off so that an A value obtained from the following formula (1) falls within a range of 20.46 to 23.54. Manufacturing method.
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 : Trimming diameter (mm) of the first flange planned portion pair
U _bd : Trimming diameter of the second flange planned portion pair (mm)
T _bg : Mass of air valve with pressure sensor scheduled for installation (g)
t: Thickness of the steel plate for disc (mm)

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