JP2019196147A - Manufacturing method of hub unit bearing - Google Patents

Abstract

To provide a manufacturing method of a hub unit bearing which can modify unbalance of a hub wheel by painting.SOLUTION: In a manufacturing method of a hub unit bearing, unbalance of a hub wheel 12 which is a rotary wheel is measured and the unbalance of the hub wheel 12 is modified by a thickness of a paint film of the hub wheel 12. Further, the hub wheel 12 has a flange part 20 to which a wheel is attached. The paint film for modifying the unbalance of the hub wheel 12 is applied to a surface 22 of the flange part 20 which is opposite to a surface 21 to which the wheel is attached.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a method for manufacturing a hub unit bearing, and more particularly to correction of unbalance of a hub ring of a hub unit bearing.

  As a conventional hub unit bearing, one in which an electrically insulating coating layer is provided on a contact surface of an outer ring member with a knuckle and at least one seal is made conductive is known (for example, see Patent Document 1). ). In this hub unit bearing, painting is performed as one of methods for providing an electrically insulating film layer.

JP 2008-230607 A

  By the way, the hub unit bearing is a bearing arranged at a position that can be seen from the gap of the wheel or from the outside at the time of wheel replacement, so corrosion prevention performance and aesthetics are required regardless of the combination with the aluminum alloy knuckle. May be painted.

  In order to coat the hub unit bearing assembly, a method is adopted in which an electrostatically charged powder coating is applied to the surface of the hub unit bearing and then baked at a low temperature. According to this method, a relatively uniform thick coating film including the ridges can be obtained. In addition, since it is baked at a low temperature within the assumed operating temperature range of the hub unit bearing (for example, at 120 ° C. for 20 minutes), a tough coating film can be obtained without damaging the seal or grease.

  On the other hand, in order to obtain high anticorrosion performance, the hub unit bearing uses a powder coating containing metal powder of zinc (density 7.14) and aluminum (density 2.7), and zinc has a density especially. Since the coating film thickness is not uniform, the hub wheel, which is a rotating wheel, is unbalanced. Note that the unbalance is a state where the center of gravity of the hub wheel is displaced in the radial direction from the center of rotation. Further, when the unbalance amount of the hub wheel exceeds a specified value, vibration is generated particularly during high-speed traveling, and steering stability and riding comfort are deteriorated.

  In general, since the hub wheel is formed by hot forging, it has a certain degree of imbalance before coating, and the above-mentioned thick powder coating is applied to a high density zinc-based powder. When using body paint, the unbalance amount of the hub wheel may exceed the specified value.

  Even if the unbalance is corrected by machining the hub wheel before painting, if the coating thickness of the powder coating is uneven, the hub wheel will eventually be unbalanced. It becomes. For this reason, a method for correcting the unbalance of the hub wheel after painting without damaging the coating film has been demanded.

  The present invention has been made in view of the above-described problems, and an object of the present invention is to provide a method of manufacturing a hub unit bearing capable of correcting the unbalance of the hub wheel by painting.

The above object of the present invention is achieved by the following configurations.
(1) A method for manufacturing a hub unit bearing, comprising measuring an unbalance of a hub wheel that is a rotating wheel and correcting the unbalance of the hub wheel by a thickness of a coating film of the hub wheel.
(2) The hub wheel has a flange portion to which a wheel is attached, and a coating film for correcting unbalance of the hub wheel is applied to a surface of the flange portion opposite to a surface to which the wheel is attached. The manufacturing method of the hub unit bearing as described in (1) characterized by the above-mentioned.
(3) The hub unit bearing manufacturing method according to (2), wherein the coating film is a coating film by powder coating.
(4) a first paint adhering step for adhering a powder paint to the hub unit bearing; a measuring step for measuring the unbalance of the hub wheel; and correcting the unbalance of the hub wheel. The hub unit bearing according to (3), further comprising: a second paint adhering step of adhering the powder paint to the flange portion by spraying; and a baking step of baking the powder paint on the hub unit bearing. Manufacturing method.

  According to the present invention, the imbalance of the painted hub wheel is measured, additional coating is applied partially, and the unbalance of the hub wheel is corrected by the thickness of the coating film of the hub wheel. The unbalance of the hub wheel can be corrected without doing so.

It is sectional drawing explaining the hub unit bearing manufactured by one Embodiment of the manufacturing method which concerns on this invention. It is the side view which looked at the hub ring shown in FIG. 1 from the inboard side.

  Hereinafter, one embodiment of a manufacturing method of a hub unit bearing concerning the present invention is described in detail based on a drawing.

  As shown in FIG. 1, the hub unit bearing 10 is an inner ring member that is separate from the outer ring member 11, the hub ring 12 that is an inner ring member, and the hub ring 12, and is integrally fixed to the hub ring 12. Inner ring 13, a plurality of balls (rolling elements) 14 arranged in two rows so as to be able to roll between the outer diameter surface of hub wheel 12 and inner ring 13 and the inner diameter surface of outer ring member 11, and a plurality of these two rows A pair of retainers 15 that respectively hold the balls 14 in the circumferential direction at substantially equal intervals, and a pair of seal devices 16 that block the opening at both ends of the bearing internal space. The hub unit bearing shown in FIG. 1 is for a driven wheel, but is not limited thereto, and may be a hub unit bearing for a driving wheel.

  The hub wheel 12 is a substantially columnar member, and a flange portion 20 that extends radially outward from the outer diameter surface is formed at an end portion on the outboard side (left side in the drawing). A plurality of hub bolts 17 for fixing a wheel and a brake rotor (not shown) are provided on the flange portion 20 at substantially equal intervals in the circumferential direction. The surface 21 on the outboard side of the flange portion 20 is a surface to which the wheel and the brake rotor are attached, and the surface 22 on the inboard side of the flange portion 20 is a surface opposite to the surface 21 on the outboard side. .

  A small-diameter step portion 12b is formed on the inboard side end portion (right side in the drawing) of the hub wheel 12. After the inner ring 13 is fitted on the small-diameter step portion 12b, the end portion of the small-diameter step portion 12b is formed with a diameter. The inner ring 13 is fixed to the hub ring 12 by caulking the outer side in the direction. In addition, an appropriate preload is applied by pressing the inner ring 13 by caulking.

  Two rows of outer ring raceway surfaces 11 a and 11 a parallel to each other are formed on the inner diameter surface of the outer ring member 11 so as to be separated from each other. Inner ring raceway surfaces 12 a and 13 a are formed on the outer diameter surfaces of the hub ring 12 and the inner ring 13, respectively, corresponding to the outer ring raceway surfaces 11 a and 11 a of the outer ring member 11. A plurality of balls 14 held by the cage 15 so as to be able to roll are arranged at equal intervals in the circumferential direction on the two rows of tracks constituted by the outer ring raceway surfaces 11a and 11a and the inner ring raceway surfaces 12a and 13a. Has been.

  The plurality of balls 14 arranged on the two rows of tracks make contact with the outer ring raceway surfaces 11a and 11a and the inner ring raceway surfaces 12a and 13a at a predetermined contact angle with each other, thereby forming a back surface combination type (DB) bearing. The Thereby, the hub wheel 12 and the inner ring 13 can rotate with respect to the outer ring member 11.

  And the manufacturing method of the hub unit bearing of this embodiment is the measurement process of measuring the 1st coating material adhesion process which adheres powder coating material to the assembly of the hub unit bearing 10, and the unbalance of the hub wheel 12 which is a rotating wheel. In order to correct the unbalance of the hub wheel 12, a second coating material adhesion step (see FIG. 2) in which powder paint is adhered to the flange portion 20 of the hub wheel 12 by spraying, and an assembly of the hub unit bearing 10 A baking step of baking the powder coating. That is, the hub unit bearing 10 is subjected to powder coating (powder coating). In addition, the display of the coating film in drawing is abbreviate | omitted.

  In the first coating material adhesion step, the powder coating material is adhered to almost the entire surface exposed to the outside of the outer ring member 11, the hub wheel 12, and the inner ring 13 of the hub unit bearing 10. In order to correct the imbalance in the second paint adhesion process, it is not necessary to uniformly apply the powder paint in the first paint adhesion process, but in order not to increase the unbalance amount, the powder paint should be made as uniform as possible. It is preferable to make it adhere.

  In the measurement step, the hub wheel 12 (including the inner ring 13) is rotated by a balance measuring device (not shown), and the position of the center of gravity G (see FIG. 2) of the hub wheel 12 is measured. In the example shown in FIG. 2, the center of gravity G of the hub wheel 12 is located on the lower left side of the hub wheel 12 in the drawing. Note that to correct the imbalance is to bring the center of gravity G closer to the rotation center P and to make the unbalance amount within a specified value. In FIG. 2, the unbalance amount of the center of gravity G (the amount of deviation of the center of gravity G from the rotation center P) is exaggerated.

  Therefore, in the second paint adhesion step, as shown in FIG. 2, in order to bring the center of gravity G of the hub wheel 12 closer to the rotation center P, the rotation center P is set from the center of gravity G of the hub wheel 12 in the flange portion 20 of the hub wheel 12. A powder paint is additionally adhered to the modified coating area A on the opposite side by spraying. In this embodiment, the powder coating material is attached to the surface 22 on the inboard side of the flange portion 20. For this reason, the coating process which corrects the imbalance of the hub wheel 12 is provided to the surface 22 on the inboard side of the flange portion 20 by the baking process. Note that a powder paint may be attached to the outer peripheral surface of the flange portion 20. Moreover, since the surface 21 on the outboard side of the flange portion 20 needs to be a flat surface for attaching a wheel or a brake rotor, the surface 21 on the outboard side is not provided with a coating film for unbalance correction. Is preferred. Moreover, the correction coating range A is not limited to FIG. 2, and can be changed as appropriate according to the balance correction amount.

  The powder paint used in the second paint adhesion step is not particularly limited, but a zinc rich paint containing a large amount of a high-density zinc component is preferable. By using a zinc rich paint, the imbalance can be corrected with a small amount of paint, and therefore the imbalance can be corrected efficiently. The powder paint used in the first paint adhesion step is not particularly limited, but the same zinc rich paint is preferable in order to obtain high anticorrosion performance.

  In the baking process, a coating film made of a powder coating is formed on almost the entire surface exposed to the outside of the outer ring member 11, the hub ring 12, and the inner ring 13 of the hub unit bearing 10. And in this embodiment, the thick coating film which corrects the imbalance of the hub wheel 12 is formed in the correction coating range A of the surface 22 on the inboard side of the flange portion 20. That is, the unbalance of the hub wheel 12 is corrected by the thickness of the coating film of the hub wheel 12.

  As described above, according to the manufacturing method of the hub unit bearing of the present embodiment, the unbalance of the painted hub wheel 12 is measured, and additional coating is partially applied to reduce the unbalance of the hub wheel 12 to the hub. Since the correction is made according to the thickness of the coating film on the wheel 12, the unbalance of the hub wheel 12 can be corrected without damaging the coating film.

  Moreover, according to the manufacturing method of the hub unit bearing of this embodiment, since the coating film which corrects the imbalance of the hub wheel 12 is given to the surface 22 on the inboard side of the flange portion 20, the wheel or the brake rotor is attached. The imbalance of the hub wheel 12 can be corrected without affecting the surface 21 on the outboard side.

  Moreover, according to the manufacturing method of the hub unit bearing of this embodiment, since the measurement process which measures the imbalance of the hub wheel 12 is provided between the first paint adhesion process and the second paint adhesion process, Even if the powder coating material cannot be uniformly deposited in the one coating material adhesion step and the unbalance amount of the hub wheel 12 increases, the unbalance of the hub wheel 12 can be corrected in the second coating material deposition step.

In addition, this invention is not limited to what was illustrated by said each embodiment, In the range which does not deviate from the summary of this invention, it can change suitably.
For example, a baking process may be added between the first paint adhesion process and the measurement process.
In addition, when it is not necessary to paint almost the entire surface of the hub unit bearing assembly, the first paint adhering step can be omitted.
The hub bolt is usually attached after powder coating, but may be attached before powder coating.

10 Hub unit bearing 11 Outer ring member 11a Outer ring raceway surface 12 Hub ring (rotating ring)
12a Inner ring raceway surface 12b Small diameter step 13 Inner ring 13a Inner ring raceway surface 14 Ball (rolling element)
15 Cage 16 Sealing device 17 Hub bolt 20 Flange part 21 Outboard side surface 22 Inboard side surface A Correction coating range G Center of gravity P Center of rotation

Claims (4)

  A hub unit bearing manufacturing method, comprising: measuring an unbalance of a hub ring which is a rotating wheel, and correcting the unbalance of the hub ring by a thickness of a coating film of the hub ring. The hub wheel has a flange portion to which the wheel is attached,
2. The method of manufacturing a hub unit bearing according to claim 1, wherein a coating for correcting unbalance of the hub wheel is applied to a surface of the flange portion opposite to a surface to which the wheel is attached.   The hub unit bearing manufacturing method according to claim 2, wherein the coating film is a coating film by powder coating. A first paint adhering step for adhering a powder paint to the hub unit bearing;
A measuring step for measuring the unbalance of the hub wheel;
A second paint adhering step of spraying powder paint onto the flange portion of the hub wheel by spray so as to correct the unbalance of the hub wheel;
The method for manufacturing a hub unit bearing according to claim 3, further comprising: a baking step of baking powder coating on the hub unit bearing.

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