JP2018150586A - Jig for surface treatment of hub unit bearing, and surface treatment method therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a jig for surface treatment, capable of preventing electric corrosion from occurring on an outer ring raceway or on an inner ring raceway upon electrically plating or coating the surfaces of an outer member and an inner member of a hub unit bearing in an assembled state.SOLUTION: A jig 27 for surface treatment comprises a stationary side jig 28 and a rotation side jig 29. The stationary side jig 28 covers the inner face of a stationary side screw hole 6, and is electrically connected to an outer member 1. The rotation side jig 29 covers the inner face of a rotation side screw hole 9, and is electrically connected to an inner member 2. The stationary side jig 28 and the rotation side jig 29 are mutually conductive when the stationary side jig 28 is in a state of covering the inner face of the stationary side screw hole 6, and the rotation side jig 29 is in a state of covering the inner face of the rotation side screw hole 9.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a method for performing surface treatment on an outer member and an inner member constituting a hub unit bearing for rotatably supporting a wheel of an automobile with respect to a suspension device, and used for performing the surface treatment. The present invention relates to a surface treatment jig.

  As a hub unit bearing for rotatably supporting automobile wheels with respect to a suspension system, an outer ring raceway is provided on the inner peripheral surface, an outer member having a stationary flange, and an inner ring raceway is provided on the outer peripheral surface. In addition, there is known one provided with an inner member having a rotation side flange, and a plurality of rolling elements arranged between the outer ring raceway and the inner ring raceway (for example, Japanese Patent Application Laid-Open No. 2008-018824). Gazette, JP2012-215269).

  Such a hub unit bearing is used in an environment in which the stationary side flange is fixed to the suspension device, the wheel and the brake rotating member are fixed to the rotating side flange, and muddy water splashes directly from the road surface. For this reason, muddy water adheres to the surfaces of the outer member and the inner member and the surface rusts, or muddy water is formed on the mating surface of the outer member and the suspension device and the mating surface of the inner member and the braking rotating member. There is a possibility that these mating surfaces are rusted and the peripheral members are soiled by rust juice. Therefore, in the hub unit bearing, in order to prevent these disadvantages, it is required to perform a rust prevention treatment on a portion where the muddy water may adhere on the surface of the outer member and the inner member. In particular, hub unit bearings for high-end vehicles have a high demand for rust prevention treatment.

  When the surface of the outer member and the inner member constituting the hub unit bearing is subjected to rust prevention treatment, it is conceivable to employ plating or coating as the rust prevention treatment. If plating or coating is applied to the outer member or inner member as a single item, it will be difficult to secure a reference surface for grinding the outer ring raceway and inner ring raceway in the subsequent processing and assembly steps. Or other parts may come off and come off. For this reason, it is preferable to perform the operation of plating or painting the surfaces of the outer member and the inner member in a state where the hub unit bearing is assembled.

  Moreover, when performing the antirust process on the surface of an outer member and an inner member, it is preferable to employ | adopt the processing method using electricity, such as electroplating, electrostatic coating, and electrodeposition coating. For example, when painting is performed by dipping or spraying without using electricity, as described in Japanese Patent Application Laid-Open No. 2012-215269, the coating of the ridge part and its peripheral part is caused by the influence of the surface tension of the paint. Becomes thin and sufficient rust prevention performance cannot be obtained. On the other hand, in the treatment methods using electricity such as electroplating, electrostatic coating, and electrodeposition coating, the ridge portion is highly dischargeable, so that the plating or coating is also thickened at the ridge portion and its peripheral portion. Can be applied.

JP 2008-018824 A JP 2012-215269 A

  However, when the outer member and the inner member are plated or coated with electricity on the surface of the outer member and the inner member with the hub unit bearing assembled, a plurality of rolling elements are interposed between the outer member and the inner member. Thus, there is a problem that electricity flows and electric corrosion occurs on the outer ring raceway and the inner ring raceway.

  The present invention has been made in view of the circumstances as described above, and its purpose is to perform surface treatment using electricity on the outer member and the inner member in a state where the hub unit bearing is assembled. Another object of the present invention is to provide a hub unit bearing surface treatment jig and a hub unit bearing surface treatment method capable of preventing the occurrence of electrolytic corrosion on the outer ring raceway and the inner ring raceway.

A hub unit bearing that is an object of the present invention includes an outer member, an inner member, and a plurality of rolling elements.
The outer member has an outer ring raceway on an inner peripheral surface, a stationary side flange for fixing to a suspension device on a radially outer side, and the stationary side flange penetrates the stationary side flange in the axial direction. Has a stationary side hole.
The inner member has an inner ring raceway on an outer peripheral surface, and has a rotation-side flange for fixing a wheel and a brake rotating member on a radially outer side of the outer side in the axial direction than the inner ring raceway. The side flange has a rotation side hole penetrating the rotation side flange in the axial direction.
The plurality of rolling elements are disposed between the outer ring raceway and the inner ring raceway.

The surface treatment jig of the hub unit bearing of the present invention is a state in which the outer member, the inner member, and the plurality of rolling elements are combined with each other in the outer member and the inner member. It is used when the surface is plated or painted using electricity, and includes a stationary jig and a rotating jig.
The stationary side jig includes a stationary side covering portion that covers an inner surface of the stationary side hole, and is electrically connected to the outer member.
The said rotation side jig | tool is provided with the rotation side cover part which covers the inner surface of the said rotation side hole, and is electrically connected with the said inward member.
The stationary side jig and the rotating side jig are covered with each other in a state where at least the inner surface of the stationary side hole is covered with the stationary side covering portion, and the inner surface of the rotating side hole is covered with the rotating side covering portion. Conduct.

  In the surface treatment jig for a hub unit bearing according to the present invention, the stationary side covering portion can be constituted by a stationary side male screw portion that can be screwed into the stationary side hole including a screw hole. The stationary male threaded portion can be composed of an axial middle portion made of metal and both axial end portions made of synthetic resin and having a larger outer diameter than the axial middle portion.

  In the surface treatment jig for the hub unit bearing of the present invention, the rotation-side jig can be constituted by a rotation-side male screw portion that can be screwed into the rotation-side screw hole including a screw hole. Moreover, the said rotation side external thread part can be comprised by the axial direction intermediate part made from metal, and the axial direction both ends made from a synthetic resin and whose outer diameter dimension is larger than the said axial direction intermediate part.

  The surface treatment method for a hub unit bearing according to the present invention comprises a combination of the outer member, the inner member and the plurality of rolling elements, and constitutes a surface treatment jig for the hub unit bearing according to the present invention. The inner surface of the stationary side hole is covered with the stationary side covering portion of the stationary side jig, and the inner surface of the rotating side hole is covered with the rotating side covering portion of the rotating side jig constituting the surface treatment jig. The stationary jig and the rotating jig are electrically connected to each other. Then, in this state, the outer member and the inner member are subjected to plating or painting using electricity.

  According to the hub unit bearing surface treatment jig and the hub unit bearing surface treatment method of the present invention, the outer member, the inner member, and the plurality of rolling elements are combined with each other. It is possible to prevent electrolytic corrosion from occurring on the outer ring raceway and the inner ring raceway when the surface of the side member is plated or painted using electricity. The inner surface of the stationary side hole is covered with the stationary side cover of the stationary jig, and the inner surface of the rotating side hole is covered with the rotating side covering of the rotating side jig. Even if the inner surface of the side hole is not masked separately, it is possible to prevent the inner surface of the stationary side hole and the inner surface of the rotating side hole from being plated or painted.

FIG. 1 is a half sectional view of a hub unit bearing which is a target of an example of an embodiment of the present invention. FIG. 2 is an enlarged view of the upper left part of FIG. FIG. 3 is a half sectional view of a hub unit bearing assembled with the surface treatment jig of one example of the embodiment of the present invention.

[Example of Embodiment]
A first example of the embodiment will be described with reference to FIGS.
First, the configuration of the target hub unit bearing will be described with reference to FIGS. 1 and 2. In this example, the hub unit bearing is for a driven wheel, and includes an outer member 1, an inner member 2, and a plurality of rolling elements 3a and 3b. However, the present invention is not limited to a hub unit bearing for a driven wheel, but can also be applied to a hub unit bearing for a driving wheel.

The outer member 1 is made of a metal such as medium carbon steel and has a cylindrical shape. The outer member 1 has double-row outer ring raceways 4 a and 4 b on the inner peripheral surface, has a stationary side flange 5 on the radially outer side of the axially intermediate portion, and a plurality of circumferential positions of the stationary side flange 5. The stationary side screw hole 6 is a stationary side hole provided so as to penetrate the stationary side flange 5 in the axial direction. In a state where the hub unit bearing of this example is assembled to an automobile, a stationary side coupling member such as a knuckle bolt used for fixing the stationary side flange 5 to the knuckle constituting the suspension device is screwed into the stationary side screw hole 6. Combined.
However, the present invention is also applicable to a hub unit bearing in which the stationary side hole is a through hole for inserting the shaft portion of the stationary side coupling member.

The inner member 2 has double-row inner ring raceways 7a and 7b on the outer peripheral surface, and has a rotation side flange 8 on the radially outer side of the outer side in the axial direction than these inner ring raceways 7a and 7b. Rotation side screw holes 9 that are rotation side holes provided so as to penetrate the rotation side flange 8 in the axial direction are provided at a plurality of locations in the circumferential direction of the flange 8. In a state where the hub unit bearing of this example is assembled to an automobile, a rotation side coupling member such as a hub bolt used to fix a wheel and a braking rotation member to the rotation side flange 8 is screwed into the rotation side screw hole 9. Is done. In this example, the inner member 2 is configured by combining the hub wheel 10 and the inner ring 11.
However, the present invention can also be applied to a hub unit bearing in which the rotation side hole is a press-fitting hole for press-fitting the shaft portion of the rotation-side coupling member.

  In addition, the axial direction outer side means the width direction outer side of the vehicle body in the assembled state to the automobile, and corresponds to the left side of FIGS. On the other hand, the inner side in the axial direction means the inner side in the width direction of the vehicle body when assembled to the automobile, and corresponds to the right side of FIGS.

  The hub wheel 10 is made of a metal such as medium carbon steel and has a cylindrical shape. The rotation-side flange 8 is provided on the radially outer side of the axially outer portion of the hub wheel 10, and the inner ring raceway 7 a in the axially outer row is provided on the outer peripheral surface of the axially intermediate portion of the hub wheel 10. Yes. The hub wheel 10 has a small-diameter step portion 12 on the outer peripheral surface of the inner portion in the axial direction. The rotation-side flange 8 is a counterbore hole that is coaxial with the rotation-side screw hole 9 and has a larger diameter than the rotation-side screw hole 9 at a position adjacent to the axially outer side of the rotation-side screw hole 9. 13. Between the counterbore 13 and the rotation side screw hole 9, there is an annular step 14 facing outward in the axial direction. The inner side surface in the axial direction of the rotation-side flange 8 is inclined at a radial position adjacent to the inner side in the radial direction of each rotation-side screw hole 9 over the entire circumference in a direction toward the inner side in the axial direction toward the inner side in the radial direction. A surface portion 15 is provided.

  The inner ring 11 is made of a metal such as bearing steel and has a cylindrical shape. The inner ring raceway 7 b in the inner row in the axial direction is provided on the outer peripheral surface of the inner ring 11. The inner ring 11 is externally fitted to the small-diameter step portion 12 of the hub wheel 10 by an interference fit, and the axial inner end portion of the inner ring 11 is suppressed by a holding portion 16 provided at the axial inner end portion of the hub wheel 10. It is attached and fixed to the hub wheel 10. In addition, the holding | suppressing part 16 is formed by bending the axial direction inner end part of the intermediate material of the hub wheel 10 outward in the radial direction by plastic working.

  The rolling elements 3a and 3b are made of metal such as bearing steel, and are disposed between the outer ring raceway 4a and the inner ring raceway 7a in the axially outer row and between the outer ring raceway 4b and the inner ring raceway 7b in the axially inner row. Each is arranged so that it can roll freely. In the illustrated example, balls are used as the rolling elements 3a and 3b. However, in a hub unit bearing for an automobile that is heavy in weight, a tapered roller may be used as the rolling element.

  The axially outer end opening of the internal space 17 that exists between the inner peripheral surface of the outer member 1 and the outer peripheral surface of the inner member 2 and in which the rolling elements 3 a and 3 b are installed is blocked by the seal ring 18. It is. On the other hand, the axially inner end opening of the outer member 1 is closed by a bottomed cylindrical bearing cap 19.

  The seal ring 18 includes an annular core bar 20 and an annular seal member 21 reinforced by the core bar 20.

  The metal core 20 is made of a metal plate, and extends in a radially outward direction from a cylindrical fitting tube portion 22 disposed in a radially intermediate portion and an axially outer end portion of the fitting tube portion 22. And an annular side plate portion 23. The cored bar 20 is fitted into the outer end 1 of the outer member 1 by an interference fit with the fitting cylinder 22, and the inner side of the side plate 23 in the axial outer end of the outer member 1. It is fixed to the outer member 1 while being axially positioned by contact.

The sealing material 21 is made of rubber, has three seal lips 24a, 24b, and 24c on the radially inner side, and has a weir 25 and a flange 26 on the radially outer side. The tip ends of the three seal lips 24a, 24b, and 24c are in sliding contact with the surface of the hub wheel 10 over the entire circumference. The weir portion 25 is provided so as to cover the radially outer end portion of the side plate portion 23 of the core metal 20, and the outer diameter dimension is larger than the outer diameter dimension of the axially outer end portion of the outer member 1. It has become. The flange portion 26 is configured in a partially conical cylinder shape, and an axially inner end portion which is a small-diameter side end portion is coupled to a radially intermediate portion of the dam portion 25. The collar portion 26 has a labyrinth that is opposed to the inclined surface portion 15 that exists in the radially intermediate portion of the axially inner side surface of the rotation-side flange 8 over the entire circumference in close proximity to the axially outer end portion that is the large-diameter side end portion. A seal is formed.
However, the present invention can also be applied to a hub unit bearing in which the seal ring that closes the axially outer end opening of the internal space does not have the dam portion 25 or the flange portion 26.

Here, among the surfaces of the parts constituting the hub unit bearing, a portion in contact with the external space of the hub unit bearing is referred to as an outer surface. In this example, a part of the outer surface of the outer member 1 and a part of the outer surface of the inner member 2 are electroplating, electrostatic coating, and electrodeposition coating, which are rust prevention treatments as the surface treatment. Such as plating or painting using electricity (hereinafter simply referred to as “plating or painting”). Specifically, the plating or coating is performed on the entire outer surface of the outer member 1 within the range indicated by the two-dot chain lines α ₁ and α ₂ in FIG. 1 (hereinafter referred to as “α ₁ part”, “α ₂ ”). 1) and the entire circumference of the outer surface of the inner member 2 within the range indicated by the two-dot chain line β in FIG. 1 (hereinafter, also referred to as “β part”). Has been. On the other hand, in this example, the inner surface of each stationary side screw hole 6 and the inner surface of each rotational side screw hole 9 are not plated or painted.
However, when carrying out the present invention, the outer surface of the outer member 1 is in a range other than “α ₁ part, α ₂ part, and the inner surface of each stationary screw hole 6”, or the outer surface of the inner member 2. Of these, the range other than the “β portion and the inner surface of each rotation-side screw hole 9”, the outer surface of the seal ring 18, and the outer surface of the bearing cap 19 may be plated or painted. When the present invention is carried out, the range of plating or coating applied to the outer surfaces of the outer member 1 and the inner member 2 is the same as the inner surfaces of the stationary screw holes 6 and the inner surfaces of the rotating screw holes 9. If it excludes, it will not be restricted to the range of this example, It can be set as the appropriate range.

In this example, when manufacturing the hub unit bearing having the above-described configuration, the α ₁ part, the α ₂ part, which are part of the outer surface of the outer member 1, and the outer surface of the inner member 2. The operation of plating or painting the β part, which is a part, is performed in a state where the parts constituting the hub unit bearing are combined with each other as shown in FIG. In other words, α ₁ part, α ₂ part, and β part are plated or painted by assembling the hub unit bearing before the α ₁ part, α ₂ part, and β part are plated or painted. In the state. In particular, in this example, when performing this operation, a surface treatment jig 27 as shown in FIG. 3 is used.

  The surface treatment jig 27 includes a stationary jig 28 and a rotation jig 29.

  The stationary side jig 28 is configured in a stepped cylindrical shape as a whole, the inner half of the axial direction is a cylindrical large-diameter shaft portion 30, and the outer half of the axial direction is a large-diameter shaft portion 30. The cylindrical small-diameter shaft portion 31 has a smaller outer diameter than that. The large-diameter shaft portion 30 and the small-diameter shaft portion 31 are arranged coaxially. The large-diameter shaft portion 30 has a stationary-side male screw portion 32 that is a stationary-side cover portion that can be screwed into the stationary-side screw hole 6 on the outer peripheral surface. In this example, the axial dimension of the stationary male screw portion 32 is larger than the axial dimension of the stationary screw hole 6. The large-diameter shaft portion 30 has an engagement hole 33 that is recessed in the axial direction at the radial center portion of the inner end surface in the axial direction. The engagement hole 33 is a part where a tool such as a hexagon wrench for rotating the stationary jig 28 can be engaged. The small-diameter shaft portion 31 has a cylindrical tip tube portion 34 at the axially outer end portion.

In this example, the stationary jig 28 is configured by coupling and fixing a metal stationary metal body 35 and a pair of stationary resin bodies 36a and 36b each made of a synthetic resin. Specifically, in the stationary side jig 28, the outer peripheral portions at both axial ends of the large-diameter shaft portion 30 are configured by a pair of stationary side resin bodies 36 a and 36 b, and the remaining portion is formed by the stationary side metal body 35. It is configured. Accordingly, the stationary male threaded portion 32 is a resin portion in which both axial end portions are constituted by a pair of stationary side resin bodies 36a and 36b, and an axially intermediate portion is a metal portion constituted by the stationary side metal body 35. Has become a part. Such a stationary-side male screw portion 32 is formed by threading a resin portion at both ends in the axial direction and a metal portion at an intermediate portion in the axial direction in one step. For this reason, as for the stationary side external thread part 32, the thread is connected over the full length of the axial direction. However, due to the difference in elastic modulus between the resin portion at both ends in the axial direction and the metal portion at the intermediate portion in the axial direction, the stationary-side male screw portion 32 has an outer diameter dimension of the resin portion at both ends in the axial direction of the intermediate portion in the axial direction. It is slightly larger than the outer diameter of the metal part.
When the stationary side hole of the outer member of the hub unit bearing is a through hole, the stationary side covering portion constituting the stationary side jig has a shape that can cover the inner surface of the through hole. Shall.

  The pair of stationary-side resin bodies 36a and 36b are fixed to the stationary-side metal body 35 by molding and are strongly fitted to the outer peripheral surface of the stationary-side metal body 35 by molding shrinkage. Further, in this state, a part of the synthetic resin constituting the pair of stationary side resin bodies 36a and 36b enters into the plurality of concave portions 37 provided on the outer peripheral surface of the stationary side metal body 35, and the stationary side metal body 35 The relative displacement in the axial direction and the circumferential direction of the pair of stationary-side resin bodies 36a and 36b is prevented. For this reason, after the formation of the stationary male screw part 32, the screw thread of the resin part at both ends in the axial direction and the screw thread of the metal part at the intermediate part in the axial direction do not become discontinuous.

  The rotation-side jig 29 is configured as a stepped cylinder as a whole, the inner end portion and the intermediate portion in the axial direction are cylindrical small-diameter shaft portions 38, and the outer end portion in the axial direction is a small-diameter shaft portion. This is a short cylindrical large-diameter shaft portion 39 having a larger outer diameter than 38. The small diameter shaft portion 38 and the large diameter shaft portion 39 are disposed coaxially. The small-diameter shaft portion 38 has a rotation-side male screw portion 40 that is a rotation-side cover portion that can be screwed into the rotation-side screw hole 9 on the outer peripheral surface. In this example, the axial dimension of the rotation-side male screw portion 40 is substantially the same as the axial dimension of the rotation-side screw hole 9. The rotation-side jig 29 has an engagement hole 41 that is recessed in the axial direction at the radial center of the outer end surface in the axial direction. The engagement hole 41 is a part where a tool such as a hexagon wrench for rotating the rotation side jig 29 can be engaged.

In this example, the rotation-side jig 29 is configured by coupling and fixing a metal rotation-side metal body 42 and a pair of rotation-side resin bodies 43a and 43b each made of a synthetic resin. Specifically, in the rotation-side jig 29, the outer peripheral portions at both axial ends of the small-diameter shaft portion 38 are configured by a pair of rotation-side resin bodies 43a and 43b, and the remaining portion is configured by the rotation-side metal body 42. Has been. Accordingly, the rotation-side male screw portion 40 is a resin portion in which both end portions in the axial direction are constituted by a pair of rotation-side resin bodies 43a and 43b, and a metal in which the axial intermediate portion is constituted by the rotation-side metal body 42. Has become a part. Such a rotation-side male screw portion 40 is formed by threading a resin portion at both ends in the axial direction and a metal portion at an intermediate portion in the axial direction in one step. For this reason, as for the rotation side external thread part 40, the thread is connected over the full length of the axial direction. However, the rotation-side male threaded portion 40 has an outer diameter dimension of the resin portion at both axial end portions of the axial intermediate portion due to a difference in elastic coefficient between the resin portion at both axial end portions and the metal portion at the axial intermediate portion. It is slightly larger than the outer diameter of the metal part.
In addition, when the rotation side hole of the inner member of the hub unit bearing is a press-fitting hole, the rotation-side cover portion constituting the rotation-side jig has a shape that can cover the inner surface of the press-fitting hole. Shall.

  In this example, the pair of rotation-side resin bodies 43a and 43b are fixed to the rotation-side metal body 42 by molding, and are strongly fitted to the outer peripheral surface of the rotation-side metal body 42 by molding shrinkage. Further, in this state, a part of the synthetic resin constituting the pair of rotation-side resin bodies 43a and 43b enters the plurality of concave portions 44 provided on the outer peripheral surface of the rotation-side metal body 42, and the rotation-side metal body 42 A relative displacement in the axial direction and circumferential direction of the pair of rotation-side resin bodies 43a and 43b is prevented. For this reason, after the rotation-side male screw portion 40 is formed, the screw thread of the resin portion at both ends in the axial direction and the screw thread of the metal portion at the intermediate portion in the axial direction do not become discontinuous.

Various metals such as an iron alloy, a copper alloy, and an aluminum alloy can be adopted as the metal constituting the stationary side metal body 35 and the rotation side metal body 42. Preferably, as the metal constituting the stationary metal body 35 and the rotating metal body 42, it is preferable to employ a metal such as stainless steel whose plating or coating is not easily formed on the surface by surface treatment using electricity.
In addition, various synthetic resins such as polyphenylene sulfide (PPS), polyacetal (POM), and polyamide (PA) are adopted as the synthetic resin constituting the stationary resin bodies 36a and 36b and the rotation side resin bodies 43a and 43b. Can do. Moreover, various reinforcing fibers, such as glass fiber, polyethylene fiber, carbon fiber, and aramid fiber, can be mixed in these synthetic resins as needed.

Using the surface treatment jig 27 having the above-described configuration, a part of the outer surface of the outer member 1 is α ₁ part, α ₂ part, and part of the outer surface of the inner member 2. When performing an operation of plating or painting a certain β portion, as shown in FIG. 3, the stationary jig 28 and the rotary jig constituting the surface treatment jig 27 with respect to the hub unit bearing. 29 is attached.

  Specifically, as shown in FIG. 3, the rotation-side male screw portion 40 constituting the rotation-side jig 29 is screwed into any one of the plurality of rotation-side screw holes 9. In addition, the inner side surface in the axial direction of the large-diameter shaft portion 39 constituting the rotation-side jig 29 is brought into contact with the stepped portion 14 existing between the rotation-side screw hole 9 and the counterbore hole 13. As a result, the inner surface of the rotation-side screw hole 9 is covered with the rotation-side male screw portion 40. In particular, in this example, both ends in the axial direction of the rotation-side screw hole 9 are in contact with large-diameter resin portions constituting both ends in the axial direction of the rotation-side male screw portion 40, and the sealing performance of the rotation-side screw hole 9 is improved. Enhanced. In addition, the rotation-side metal body 42 constituting the rotation-side jig 29 is electrically connected to the inner member 2 (a state where electricity can be passed between the rotation-side metal body 42 and the inner member 2). . In other words, the metal part constituting the axially intermediate part of the rotating male screw part 40 is electrically connected to the axially intermediate part of the rotating screw hole 9 and the axial direction of the large-diameter shaft part 39 is connected to the step part 14. The inner side is electrically connected. In this example, in this state, the axial dimension of the rotation-side male screw portion 40 is regulated so that the distal end portion of the rotation-side male screw portion 40 does not interfere with the flange portion 26 and the dam portion 25 that constitute the seal ring 18. ing. Further, when implementing the present invention, the rotation side resin body 43a on the outer side in the axial direction is replaced with a part of the metal body on the rotation side, and a configuration including only the rotation side resin body 43b on the inner side in the axial direction is adopted. Alternatively, it is possible to adopt a configuration in which the entire rotation-side male screw portion is made of a metal portion without providing the resin portion.

  Further, as shown in FIG. 3, the stationary male screw portion 32 constituting the stationary jig 28 is screwed into any one stationary screw hole 6 of the plurality of stationary screw holes 6. As a result, the inner surface of the stationary screw hole 6 is covered with the stationary male screw portion 32. In particular, in this example, both ends of the stationary side screw hole 6 in the axial direction are in contact with large-diameter resin portions constituting both ends of the stationary side male threaded portion 32 in the axial direction, so that the sealing performance of the stationary side screw hole 6 is improved. Is increased. Further, a stationary metal body 35 constituting the stationary jig 28 is electrically connected to the outer member 1. That is, the metal part which comprises the axial direction intermediate part of the stationary side external thread part 32 is electrically connected to the axial direction intermediate part of the said stationary side screw hole 6. FIG. In the case of carrying out the present invention, it is possible to adopt a configuration in which the entire stationary-side male screw portion is made of a metal portion without providing the resin portion.

  Further, by adjusting the screwing position of the stationary-side male screw portion 32 with respect to the stationary-side screw hole 6 in the state where the circumferential phases of the rotating-side screw hole 9 and the stationary-side screw hole 6 are matched, The axially outer end surface of the distal end cylindrical portion 34 provided at the axially outer end portion of the stationary metal body 35 is pressed against and electrically connected to the axially inner end surface of the metal body 42. Thereby, the rotation side metal body 42 and the stationary side metal body 35 are made conductive. As a result, the outer member 1 and the inner member 2 are electrically connected via the stationary metal body 35 and the rotating metal member 42, and the potential difference between the outer member 1 and the inner member 2 is zero. That is, the outer member 1 and the inner member 2 have the same potential. In this example, in this state, by tightening the stationary male threaded portion 32, the axially outer end edge portion of the tip tube portion 34 is elastically lightly bited into the axially inner end surface of the rotating side metal body 42. ing.

In this example, the stationary jig 28 and the rotating jig 29 are attached to the hub unit bearing as described above. Further, an appropriate method is applied to the inner surface of the remaining rotation-side screw hole 9 among the plurality of rotation-side screw holes 9 and the inner surface of the remaining stationary-side screw hole 6 among the plurality of stationary-side screw holes 6. Mask with. Further, the outer surface of the outer member 1 is in a range other than “α ₁ portion, α ₂ portion, and the inner surface of each stationary screw hole 6” or “β portion and each rotation of the outer surface of the inner member 2”. Masking is applied to the range other than the “inner surface of the side screw hole 9”, the outer surface of the seal ring 18, and the outer surface of the bearing cap 19 by an appropriate method as necessary. In this state, the α ₁ part and α ₂ part which are part of the outer surface of the outer member 1 and the β part which is part of the outer surface of the inner member 2 are plated or Apply paint.

As described above, in this example, the outer member 1 and the inner member 2 are electrically connected via the stationary side metal body 35 and the rotation side metal body 42, whereby the outer member 1 and the inner member 2 are electrically connected. Α ₁ part and α ₂ part which are part of the outer surface of the outer member 1 and β part which is part of the outer surface of the inner member 2 in a state where the potential difference with the side member 2 becomes zero In contrast, plating or painting using electricity is performed. For this reason, when this plating or coating is performed, electricity flows between the outer member 1 and the inner member 2 via the plurality of rolling elements 3a and 3b, and the double row outer ring raceways 4a and 4b and It is possible to prevent electrolytic corrosion from occurring on the inner ring raceways 7a and 7b in the row.

  The inner surface of the stationary side screw hole 6 to which the stationary side male screw portion 32 is screwed is covered with the stationary side male screw portion 32, and the inner surface of the rotating side screw hole 9 to which the rotating side male screw portion 40 is screwed. Is covered with the rotation-side male screw portion 40. For this reason, the inner surface of the rotation-side screw hole 9 and the inner surface of the stationary-side screw hole 6 are plated or painted without separately masking the inner surface of the rotation-side screw hole 9 and the inner surface of the stationary-side screw hole 6. Can be prevented. In particular, in this example, since the large-diameter resin portions constituting both end portions in the axial direction of the rotation side male screw portion 40 are in contact with both end portions in the axial direction of the rotation side screw hole 9, the seal of the rotation side screw hole 9 is provided. Can increase the sex. Therefore, it is possible to more effectively prevent the inner surface of the rotation-side screw hole 9 from being plated or painted. Moreover, since the large diameter resin part which comprises the axial direction both ends of the stationary side male screw part 32 is contacting the axial direction both ends of the stationary side screw hole 6, the sealing performance of the stationary side screw hole 6 improves. Can do. Accordingly, it is possible to more effectively prevent the inner surface of the stationary screw hole 6 from being plated or painted.

  In this example, by tightening the stationary-side male screw portion 32, the axially outer end edge portion of the distal end tubular portion 34 is elastically lightly bited into the axially inner end surface of the rotating-side metal body 42. For this reason, even when plating or painting is performed on the inner end surface in the axial direction of the rotating side metal body 42 or the outer end surface in the axial direction of the tip cylindrical portion 34 when performing plating or painting, The electrical connection state between the axial inner end surface of the rotation side metal body 42 and the axial outer end surface of the distal end cylindrical portion 34 can be maintained. When carrying out the present invention, a tip cylindrical portion is provided at the inner end in the axial direction of the rotating side metal body, and the inner end edge in the axial direction of the leading end cylindrical portion is formed on the outer end surface in the axial direction of the stationary side metal body. It is also possible to adopt a configuration that allows lightly biting in elastically.

  In JP 2008-018824A, shot peening is performed using a non-ferrous shot material on the surface as a rust prevention treatment performed on the surface of the outer member or the inner member in a state where the hub unit bearing is assembled. A treatment for forming a rust preventive film on the surface by applying is described. However, in this rust prevention treatment, a non-ferrous shot material having a large mass is struck against the surface on which the rust preventive film is to be formed, so the periphery of the surface on which the rust preventive film is to be formed is a metal part as a whole. That is, it is necessary to be a portion that is not damaged even if the shot material hits. Therefore, the rust prevention treatment is performed in the vicinity of the surface on which the rust prevention film is to be formed, like the hub unit bearing which is the object of this example, and the dam portion 25 which is a part of the seal material 21 constituting the seal ring 18. It cannot be applied to a structure in which the heel part 26 exists. On the other hand, since the rust prevention process employ | adopted by this example is the plating or the painting using electricity, a rust prevention process can be performed, without damaging the dam part 25 and the collar part 26. FIG.

When carrying out the present invention, an insulating coating such as chromate or enamel is applied to the contact surfaces of the stationary metal body and the rotating metal body, and plating or painting using electricity is formed on these contact surfaces. It is preferable to make it difficult to do. In the embodiment, since the tip end portion of the rotating metal body is lightly cut into the end surface of the stationary metal body, the rotating metal body penetrates the insulating coating and is electrically connected to the stationary metal body.
In addition, in a state where the stationary jig and the rotating jig are assembled to the hub unit bearing, the stationary jig and the rotating jig can be conducted through another conductor.
Furthermore, as a surface treatment jig, a stationary jig and a rotating jig are integrated, that is, the stationary jig and the rotating jig are electrically connected to each other before being assembled to the hub unit bearing. You can also adopt what you are doing.

DESCRIPTION OF SYMBOLS 1 Outer member 2 Inner member 3a, 3b Rolling element 4a, 4b Outer ring raceway 5 Stationary side flange 6 Stationary side screw hole 7a, 7b Inner ring raceway 8 Rotation side flange 9 Rotation side screw hole 10 Hub ring 11 Inner ring 12 Small diameter step 13 Countersunk hole 14 Step part 15 Inclined surface part 16 Suppressing part 17 Internal space 18 Seal ring 19 Bearing cap 20 Core metal 21 Sealing material 22 Fitting cylinder part 23 Side plate part 24a, 24b, 24c Seal lip 25 Weir part 26 Gutter part 27 Surface treatment jig 28 Stationary side jig 29 Rotation side jig 30 Large-diameter shaft portion 31 Small-diameter shaft portion 32 Stationary-side male screw portion 33 Engagement hole 34 End tube portion 35 Stationary-side metal body 36a, 36b Stationary-side resin body 37 Concave portion 38 Small-diameter shaft portion 39 Large-diameter shaft portion 40 Rotating-side male screw portion 41 Engagement hole 42 Rotating-side metal body 43a, 43b Rotating-side resin body 44

Claims (3)

The outer ring raceway provided on the inner peripheral surface, the stationary side flange provided on the radially outer side, and the stationary side hole provided in the stationary side flange so as to penetrate the stationary side flange in the axial direction. An outer member;
An inner ring raceway provided on the outer peripheral surface, a rotation side flange provided on the radially outer side of the outer side in the axial direction than the inner ring raceway, and the rotation side flange provided on the rotation side flange penetrating in the axial direction An inner member having a rotating side hole,
A plurality of rolling elements disposed between the outer ring raceway and the inner ring raceway;
Of the hub unit bearing provided with the outer member and the inner member on the surfaces of the outer member, the inner member and the plurality of rolling elements in combination with each other. A surface treatment jig used for performing plating or coating,
It has a stationary jig and a rotating jig,
The stationary side jig includes a stationary side covering portion that covers an inner surface of the stationary side hole, and can be electrically connected to the outer member,
The rotation-side jig includes a rotation-side cover that covers the inner surface of the rotation-side hole, and can be electrically connected to the inner member.
The stationary side jig and the rotating side jig are covered with each other in a state where at least the inner surface of the stationary side hole is covered with the stationary side covering portion, and the inner surface of the rotating side hole is covered with the rotating side covering portion. Conducting,
Hub unit bearing surface treatment jig. The stationary side cover portion is configured by a stationary side male screw portion that can be screwed into the stationary side hole formed of a screw hole,
The stationary male threaded portion includes a metal axial intermediate portion and synthetic resin, and has both axial end portions that are larger in outer diameter than the axial intermediate portion,
The rotation-side cover portion is configured by a rotation-side male screw portion that can be screwed into the rotation-side hole including a screw hole,
The rotation-side male screw portion includes a metal axial intermediate portion and both ends in the axial direction, which are made of synthetic resin and have a larger outer diameter than the axial intermediate portion.
The jig for surface treatment of the hub unit bearing according to claim 1. The outer ring raceway provided on the inner peripheral surface, the stationary side flange provided on the radially outer side, and the stationary side hole provided in the stationary side flange so as to penetrate the stationary side flange in the axial direction. An outer member;
An inner ring having an inner ring raceway on the outer peripheral surface, a rotation side flange on a radially outer side of the outer side in the axial direction than the inner ring raceway, and a rotation side hole penetrating the rotation side flange in the axial direction on the rotation side flange. A member,
A plurality of rolling elements disposed between the outer ring raceway and the inner ring raceway;
A surface treatment method for a hub unit bearing comprising:
The jig for surface treatment of the hub unit bearing according to any one of claims 1 and 2,
The outer member, the inner member, and the plurality of rolling elements are combined with each other, the inner surface of the stationary side hole is covered with the stationary side covering portion, and the inner surface of the rotating side hole is covered with the rotating side covering portion. In the state where the stationary side jig and the rotation side jig are electrically connected to each other, the outer member and the inner member are subjected to plating or painting using electricity,
Hub unit bearing surface treatment method.

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