JP2010060097A - Method of assembling constant velocity universal joint - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of assembling a constant velocity universal joint, highly accurately preventing grease leakage and sharing the segments even if boot bands having different diameters are used. <P>SOLUTION: In the method for assembling the constant velocity universal joint, the diameter of the boot band 18 is reduced to mount a boot 10. On the outer diameter side of the boot band 18, the plurality of segments 31 having inner diameter surfaces 32 formed as circular arc surfaces are circumferentially arranged in a ring shape. The diameter of the boot band 18 is reduced by moving each segment 31 radially inward so that the center of curvature of the inner diameter surfaces 32 of the segments 31 is radially displaced relative to the center of the boot band 18. In this tightened state, the entire circumferential outer diameter arc surface of the boot band 18, the diameter of which has been reduced, is formed by the circular arc surfaces formed by the inner diameter surfaces 32 of all the segments 31. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a constant velocity universal joint assembling method.

  Constant velocity universal joints used for power transmission in automobiles and various industrial machines are equipped with bellows-shaped boots to prevent foreign materials such as dust from entering the joints and leakage of grease enclosed in the joints. Is done.

  This type of boot includes a large diameter portion fixed to an outer ring as an outer joint member of a constant velocity universal joint, a small diameter portion fixed to a shaft extending from an inner ring as an inner joint member, a large diameter portion and a small diameter portion. And a bellows portion in which valley portions and mountain portions are alternately formed. The large-diameter portion and the small-diameter portion are fixed by attaching a boot band.

  The constant velocity universal joint has the function of rotating while taking an operating angle or sliding in the axial direction, so the boot attached to it has the behavior of the constant velocity universal joint. It has a bellows shape to ensure flexibility to follow. That is, the bellows-shaped boot is deformed to follow the movement of the constant velocity universal joint that takes an operating angle or slides.

  There are rubber boots using chloroprene rubber and resin boots using thermoplastic elastomer materials for constant velocity universal joint boots, but resin boots are more durable than rubber boots. Is expanding.

  In recent years, a metal band (a band without protrusions) having no protrusion on the outer diameter surface (outer peripheral surface) may be used as a boot band for fastening the constant velocity universal joint boot. In such a metal band, first, a fitting portion (a large-diameter portion of the boot or a small-diameter portion of the boot) is externally fitted in a loose fit, and in this state, the reduced-diameter crimp is performed to tighten the attached portion. It is.

  Therefore, the devices described in Patent Document 1 and Patent Document 2 are used for diameter reduction caulking. The apparatus described in Patent Document 1 is a device in which a plurality of segments whose inner diameter surfaces are circular arc surfaces are arranged in a ring shape along the circumferential direction, and these segments are moved in the radial direction.

The device described in Patent Document 2 includes a plurality of claw portions arranged at a predetermined pitch along the circumferential direction, and slides the claw portions in the radial direction while guiding the claw portions in a guide groove.
Japanese Patent No. 4018188 Japanese Patent Laid-Open No. 2007-232128

  However, as in the device described in Patent Document 1, when a band without protrusions is caulked with a plurality of segments (frames) whose inner surface is an arc surface, the center of curvature of the inner surface of each segment Since the center of the band and the center of the band coincide with each other, if the diameter of the arc surface of the inner diameter surface is too larger than the outer diameter of the band before caulking, there is a risk that a portion where the circumferential end of the segment does not contact the band There is. In such a case, the portion of the band that does not come into contact with the segment will not receive a force from the segment. For this reason, grease leakage is likely to occur from a portion where no force is received from the segment.

  On the other hand, if the diameter of the arc surface of the inner diameter surface is too smaller than the outer diameter of the band before caulking, there may be a portion where the central portion of the inner diameter surface of the segment does not contact the band. In such a case, the portion of the band that does not come into contact with the segment will not receive a force from the segment. For this reason, grease leakage is likely to occur from a portion where no force is received from the segment.

  By the way, the band diameter to be used differs depending on the size of the constant velocity universal joint. For this reason, in the thing provided with the above segments, when the size was different, the segment could not be shared.

  Moreover, in the thing of patent document 2, a clearance gap produces between the nail | claw parts adjacent to the circumferential direction at the time of caulking. For this reason, there is a portion that is not crimped in the band, and grease leakage is likely to occur in this portion.

  In view of the above problems, the present invention provides a constant velocity universal joint assembling method that can prevent grease leakage with high accuracy and can share a segment even if the boot band diameter is different.

  The constant velocity universal joint assembling method of the present invention is a constant velocity universal joint assembling method in which a boot band is reduced in diameter and mounted on a boot, wherein a plurality of inner diameter surfaces of the boot band are arcuate surfaces on the outer diameter side. The segments are arranged in a ring shape along the circumferential direction, and each segment is moved radially inward so that the center of curvature of the inner diameter surface of the segment is displaced in the radial direction with respect to the center of the boot band. Clamping is performed by reducing the diameter of the band, and in this tightened state, the outer circumferential surface of the outer diameter of the reduced diameter boot band is formed by the circular arc surface formed by the inner diameter surface of all segments.

  According to the constant velocity universal joint assembling method of the present invention, the arc surface formed by the inner diameter surface of all the segments forms the outer diameter all-round arc surface of the reduced diameter boot band. The part which does not contact between a surface and a boot band becomes difficult to produce.

  Moreover, since each segment is moved radially inward so that the center of curvature of the inner diameter surface of the segment is displaced in the radial direction with respect to the center of the boot band, it corresponds to a boot band having a different outer diameter. be able to.

  When the radius of the outer diameter surface of the boot band in the crimped state is R and the radius of curvature of the inner diameter surface of the segment is r, the ratio (r / R) is 1.00 to 1.30. In the tightened state, the band flesh escapes to the circumferential end portion (intersection portion of the arc) of the inner diameter surface of the segment. For this reason, the entire inner diameter surface of the segment comes into contact with the outer diameter surface of the boot band.

  When the radius of the outer diameter surface of the boot band in the crimped state is R and the radius of curvature of the inner diameter surface of the segment is r, the ratio (r / R) is 0.90 to 0.99. In the tightened state, the band flesh escapes to the center of the inner diameter surface of the segment. For this reason, the entire inner diameter surface of the segment comes into contact with the outer diameter surface of the boot band.

  The hardness of the boot band contact surface of the inner diameter surface of the segment is preferably HRC45 to HRC65. As a result, the boot band contact surface of the segment is excellent in wear resistance.

  For this reason, it is preferable to subject the boot band contact surface to an abrasion-resistant surface treatment. As the wear-resistant surface treatment, any one or more of dry plating, wet plating, melting treatment, thermal spraying, ion implantation, sulfurization treatment, chemical conversion treatment, surface heat treatment and shot peening are performed, A surface with a small coefficient of friction is formed.

  The boot may be made of resin or rubber. The boot band may be made of aluminum or iron.

  In the present invention, a portion that does not contact between the inner diameter surface of the segment and the boot band is less likely to occur. For this reason, the assembled constant velocity universal joint can prevent grease leakage and intrusion of water or the like from the outside, and can exhibit a stable function over a long period of time.

  And even if it is one type of segment, it can respond to the boot band from which an outer diameter differs, and can achieve cost reduction.

  If the ratio (r / R) is set to 1.00 to 1.30 or the ratio (r / R) is set to 0.90 to 0.99, the band flesh escapes during caulking, and the inner surface of the segment The whole and the outer diameter surface of the boot band come into stable contact. For this reason, the reliability of the grease leakage prevention function can be improved.

  By making the surface hardness of the boot band contact surface HRC45 to HRC65 or applying wear-resistant surface treatment, the inner diameter surface of the segment is less likely to wear, and has excellent durability, and the segment has a stable clamping force over a long period of time. It can be demonstrated.

  The boot may be made of resin or rubber, and the boot band may be made of aluminum or iron. That is, in the constant velocity universal joint assembling method according to the present invention, a stable tightening force can be exerted on various types of boots and boot bands.

  Hereinafter, embodiments of the present invention will be described with reference to FIGS.

  FIG. 5 shows a constant velocity universal joint. The constant velocity universal joint includes an outer ring 1 as an outer joint member in which a plurality of guide grooves (track grooves) 4 are formed in the inner circumferential surface in the axial direction, and a plurality of outer circumferential surfaces. A plurality of balls arranged on a ball track formed in cooperation with an inner ring 2 as an inner joint member in which a guide groove (track groove) 5 is formed, a guide groove 4 of the outer ring 1 and a guide groove 5 of the inner ring 2 3, a cage 8 having a pocket 8 a for accommodating the ball 3, and the like. The shaft 9 is coupled to the inner periphery of the inner ring 2 via torque transmission means such as serrations and splines. The constant velocity universal joint of this embodiment is an undercut free type (UJ) in which the guide grooves 4 and 5 have an arc portion and a straight portion. The constant velocity universal joint may be a Barfield type constant velocity universal joint (BJ) in which the guide grooves 4 and 5 are formed only by arc portions.

  The constant velocity universal joint boot 10 is formed of, for example, a thermoplastic elastomer such as ester, olefin, urethane, amide, or styrene. Thermoplastic elastomers have intermediate properties between resin and rubber. The thermoplastic elastomer can be processed with an ordinary thermoplastic resin molding machine.

  The constant velocity universal joint boot 10 may be a thermoplastic polyester elastomer having a hardness of 35 to 50 according to a type D durometer as defined in JIS K6253. The thermoplastic polyester elastomer is a material having an intermediate elastic modulus between a flexible material such as vulcanized rubber and a highly rigid material such as a thermoplastic resin. This thermoplastic polyester elastomer has the characteristics of both vulcanized rubber and thermoplastic resin. It is elastic to restore its original shape even when deformed, higher mechanical strength than vulcanized rubber, and general thermoplasticity. It is a material that exhibits characteristics such as thermoplasticity that can be applied to all molding methods applicable to resins.

  The constant velocity universal joint boot 10 is connected to a large-diameter portion 13 attached to an opening end portion of an outer joint member (outer ring 1) of the constant velocity universal joint and an inner joint member (inner ring 2) of the constant velocity universal joint. A bellows portion having a small-diameter portion 14 attached to the shaft 9, a bellows portion provided between the large-diameter portion 13 and the small-diameter portion 14 and alternately disposed along the axial direction. 15. The mountain portion 7 and the valley portion 6 are connected by an inclined portion (connecting portion) 12.

  On the outer peripheral surface of the outer ring 1 on the opening side, a boot mounting portion 16 (circumferential concave groove formed of a groove along the circumferential direction. In FIG. Is omitted), and the large-diameter portion 13 is externally fitted to the boot mounting portion 16. Then, the large-diameter portion 13 is fixed to the outer ring 1 by fitting the boot band 18 to the outer peripheral surface of the large-diameter portion 13 of the boot 10.

  The shaft 9 is provided with a boot mounting portion 22 having a boot mounting groove 20 along the circumferential direction at a position protruding from the outer ring 1 by a predetermined amount, and the small diameter portion 14 is externally fitted to the boot mounting portion 22. The small-diameter portion 14 is fixed to the shaft 9 by fitting the boot band 18 to the outer peripheral surface of the small-diameter portion 14 of the boot 10.

  By the way, as the boot band 18 of this constant velocity universal joint, a ring body (metal band without a protrusion) having no protrusion on the outer peripheral surface is used. Then, the boot is mounted by reducing the diameter. Therefore, the bootband diameter reducing device shown in FIGS. 1 to 3 is used for the diameter reduction.

  The bootband diameter reducing device includes a plurality of (in this case, eight) segments 31 along the circumferential direction, and a drive mechanism (not shown) that reciprocates the segments 31 in the radial direction. The segment 31 is formed of a block body whose inner diameter surface 32 is an arc surface. That is, the block body constituting the segment 31 includes side surfaces 33 and 34 facing each other along the circumferential direction, the inner diameter surface 32, and the outer diameter surface 35 facing the inner diameter surface 32. This is a block piece having a trapezoidal cross section.

  Next, a method for mounting the boot band 18 using the boot band diameter reducing device will be described. First, the boot band 18 is in a state of being loosely fitted to the large diameter portion 13 or the small diameter portion 14 of the boot 10. In this state, as shown in FIG. 1, the side surfaces 33 and 34 face the plurality of segments 31 to the segments 31 adjacent in the circumferential direction, and a predetermined gap is formed. This gap is set so that when the segments 31 are slid inward in the radial direction as will be described later, the adjacent segments 31 in the circumferential direction come into contact with each other and do not hinder the sliding.

  In this state, the inner diameter surface 32 of each segment 31 is substantially in contact with the outer diameter surface 18 a of the boot band 18. From this state, each segment 31 slides radially inward. In this case, the segments 31 (31a, 31b, 31c, 31d, 31e, 31f, 31g, 31h) are center lines La, Lb, Lc, Ld, Le, Lf passing through the center O of the outer diameter surface 18a of the boot band 18. , Slide along Lg, Lh.

  In the final slide state, as shown in FIG. 2, the center of curvature A of the inner diameter surface 32 of the first segment 31a is located on the opposite side of the segment 31a from the center O of the outer diameter surface 18a of the boot band 18. . The center of curvature B of the inner diameter surface 32 of the second segment 31b is located on the opposite side of the segment 31b from the center O of the outer diameter surface 18a of the boot band 18. The center of curvature C of the inner diameter surface 32 of the third segment 31 c is located on the opposite side of the segment 31 c from the center O of the outer diameter surface 18 a of the boot band 18. The center of curvature D of the inner diameter surface 32 of the fourth segment 31d is located on the opposite side of the segment 31d from the center O of the outer diameter surface 18a of the boot band 18. The center of curvature E of the inner diameter surface 32 of the fifth segment 31e is located on the opposite side of the segment 31e from the center O of the outer diameter surface 18a of the boot band 18. The center of curvature F of the inner diameter surface 32 of the sixth segment 31f is located on the opposite side of the segment 31f from the center O of the outer diameter surface 18a of the boot band 18. The center of curvature G of the inner diameter surface 32 of the seventh segment 31g is located on the opposite side of the segment 31g from the center O of the outer diameter surface 18a of the boot band 18. The center of curvature H of the inner diameter surface 32 of the eighth segment 31 h is located on the opposite side of the segment 31 h from the center O of the outer diameter surface 18 a of the boot band 18.

  That is, as shown in FIG. 3, when the radius of the outer diameter surface 18a of the boot band 18 is R and the radius of the inner diameter surface 32 of the segment 31 is r, the ratio (r / R) is 1.00 to 1. .30. For this reason, as shown in FIG. 3, in the state where the central portion 36 of the inner diameter surface 32 of the segment 31 is in contact with the outer diameter surface 18 a of the boot band 18, the circumferential end portions 37 and 38 of the inner diameter surface 32 of the segment 31. On the side, a range that does not contact the outer diameter surface 18a of the boot band 18 occurs.

  However, in this caulking, the boot band 18 is pressed toward the inner diameter side at the central portion 36 of the segment 31, so that the central portion 36 of the inner diameter surface 32 of each segment 31 moves toward the circumferential end portions 37 and 38. The meat of the boot band 18 will escape. For this reason, the boot band 18 can be tightened in a state where the entire inner diameter surface 32 of all the segments 31 and the outer diameter surface 18a of the boot band 18 are in contact with each other.

  The outer diameter surface 18a of the boot band 18 after crimping has a shape as shown in FIG. In FIG. 4, the RA range is a range crimped by the first segment 31a, the RB range is a range crimped by the second segment 31b, and the RC range is the third segment 31c. The RD range is a range crimped by the fourth segment 31d, the RE range is a range crimped by the fifth segment 31e, and the RF range is the sixth range. It is the range crimped by the segment 31f, the RG range is the range crimped by the seventh segment 31g, the RH range is the range crimped by the eighth segment 31h, and the RH range Is a range crimped by the fourth segment 31h.

  In the RA range, the center coincides with the center A of the inner diameter surface 32 of the first segment 31a, and the radius RA coincides with the radius r of the first segment 31a. In the RB range, the center coincides with the center B of the inner diameter surface 32 of the second segment 31b, and the radius RB coincides with the radius r of the second segment 31b. In the RC range, the center coincides with the center C of the inner diameter surface 32 of the third segment 31c, and the radius RC coincides with the radius r of the third segment 31c. In the RD range, the center coincides with the center D of the inner diameter surface 32 of the fourth segment 31d, and the radius RD coincides with the radius r of the fourth segment 31d. In the RE range, the center coincides with the center E of the inner diameter surface 32 of the fifth segment 31e, and the radius RE coincides with the radius r of the fifth segment 31e. In the RF range, the center coincides with the center F of the inner diameter surface 32 of the sixth segment 31f, and the radius RF coincides with the radius r of the sixth segment 31f. In the RG range, the center coincides with the center G of the inner diameter surface 32 of the seventh segment 31g, and the radius RG coincides with the radius r of the seventh segment 31g. In the RH range, the center coincides with the center H of the inner diameter surface 32 of the eighth segment 31h, and the radius RH coincides with the radius r of the eighth segment 31h.

  In this way, the arc surface formed by the inner diameter surface of all the segments 31 forms the outer peripheral full-circular arc surface of the reduced diameter boot band 18. Note that RA range = RB range = RC range = RD range = RE range = RF range = RG range = RH range. By the way, if the ratio (r / R) is less than 1.00, only the central portion 36 of each segment 31 cannot be set to contact the boot band 18, and if the ratio (r / R) exceeds 1.3, There is a possibility that the gap between the inner peripheral surface 32 of the segment 31 and the boot band 18 on the circumferential end 37, 38 side becomes too large to contact the outer peripheral surface of the boot band 18 on the circumferential end 37, 38 side. There is.

  In the present invention, the arc surface formed by the inner diameter surface 32 of all the segments 31 forms the entire outer peripheral arc surface of the reduced diameter boot band 18. The part which does not contact between 18 becomes difficult to produce. For this reason, the assembled constant velocity universal joint can prevent grease leakage and intrusion of water or the like from the outside, and can exhibit a stable function over a long period of time.

  Moreover, since each segment 31 is moved radially inward so that the center of curvature of the inner diameter surface 32 of the segment 31 is displaced in the radial direction with respect to the center of the boot band 18, the boots having different outer diameters. The band 18 can be handled. For this reason, even if it is one type of segment 31, it can respond to the boot band 18 from which an outer diameter differs, and can achieve cost reduction.

  Next, FIG. 6 shows another device for reducing the diameter of the boot band. In this case, when the caulking is started, only the circumferential end portions 37 and 38 of the inner diameter surface 32 of each segment 31 are the outer diameter surfaces of the boot band 18. 18a is in contact. From this state, each segment 31 slides radially inward. Also in this case, the segments 31 (31a, 31b, 31c, 31d, 31e, 31f, 31g, 31h) are center lines La, Lb, Lc, Ld, Le, passing through the center O of the outer diameter surface 18a of the boot band 18. Slide along Lf, Lg, and Lh.

  In the final slide state, as shown in FIG. 7, the center of curvature A of the inner diameter surface 32 of the first segment 31 a is positioned closer to the segment 31 a than the center O of the outer diameter surface 18 a of the boot band 18. The center of curvature B of the inner diameter surface 32 of the second segment 31b is located closer to the segment 31b than the center O of the outer diameter surface 18a of the boot band 18. The center of curvature C of the inner diameter surface 32 of the third segment 31 c is located closer to the segment 31 c than the center O of the outer diameter surface 18 a of the boot band 18. The center of curvature D of the inner diameter surface 32 of the fourth segment 31d is located closer to the segment 31d than the center O of the outer diameter surface 18a of the boot band 18. The center of curvature E of the inner diameter surface 32 of the fifth segment 31e is located closer to the segment 31e than the center O of the outer diameter surface 18a of the boot band 18. The center of curvature F of the inner diameter surface 32 of the sixth segment 31 f is located on the segment 31 f side of the center O of the outer diameter surface 18 a of the boot band 18. The center of curvature G of the inner diameter surface 32 of the seventh segment 31g is located closer to the segment 31g than the center O of the outer diameter surface 18a of the boot band 18. The center of curvature H of the inner diameter surface 32 of the eighth segment 31 h is located on the segment 31 h side of the center O of the outer diameter surface 18 a of the boot band 18.

  That is, as shown in FIG. 8, when the radius of the outer diameter surface 18a of the boot band 18 is R and the radius of the inner diameter surface 32 of the segment 31 is r, the ratio (r / R) is 0.90-0. .99. For this reason, as shown in FIG. 8, in the state where the circumferential end portions 37 and 38 of the inner diameter surface 32 of the segment 31 are in contact with the outer diameter surface 18 a of the boot band 18, the central portion 36 of the inner diameter surface 32 of the segment 31. In this case, a range that does not come into contact with the outer diameter surface 18a of the boot band 18 occurs.

  However, in this caulking, the boot band 18 is pressed toward the inner diameter side by the circumferential end portions 37 and 38 of each segment 31, so that the central portion 36 side from the circumferential end portions 37 and 38 of each segment 31. The flesh of the boot band 18 will escape. For this reason, the boot band 18 can be tightened in a state where the entire inner diameter surface 32 of all the segments 31 and the outer diameter surface 18a of the boot band 18 are in contact with each other.

  The outer diameter surface 18a of the boot band 18 after crimping has a shape as shown in FIG. In FIG. 9, the RA range is a range crimped by the first segment 31a, the RB range is a range crimped by the second segment 31b, and the RC range is the third segment 31c. The RD range is a range crimped by the fourth segment 31d, the RE range is a range crimped by the fifth segment 31e, and the RF range is the sixth range. It is the range crimped by the segment 31f, the RG range is the range crimped by the seventh segment 31g, the RH range is the range crimped by the eighth segment 31h, and the RH range Is a range crimped by the fourth segment 31h.

  In the RA range, the center coincides with the center A of the inner diameter surface 32 of the first segment 31a, and the radius RA coincides with the radius r of the first segment 31a. In the RB range, the center coincides with the center B of the inner diameter surface 32 of the second segment 31b, and the radius RB coincides with the radius r of the second segment 31b. In the RC range, the center coincides with the center C of the inner diameter surface 32 of the third segment 31c, and the radius RC coincides with the radius r of the third segment 31c. In the RD range, the center coincides with the center D of the inner diameter surface 32 of the fourth segment 31d, and the radius RD coincides with the radius r of the fourth segment 31d. In the RE range, the center coincides with the center E of the inner diameter surface 32 of the fifth segment 31e, and the radius RE coincides with the radius r of the fifth segment 31e. In the RF range, the center coincides with the center F of the inner diameter surface 32 of the sixth segment 31f, and the radius RF coincides with the radius r of the sixth segment 31f. In the RG range, the center coincides with the center G of the inner diameter surface 32 of the seventh segment 31g, and the radius RG coincides with the radius r of the seventh segment 31g. In the RH range, the center coincides with the center H of the inner diameter surface 32 of the eighth segment 31h, and the radius RH coincides with the radius r of the eighth segment 31h.

  Therefore, also in this case, the outer circumferential surface of the outer diameter of the reduced boot band 18 is formed by the circular arc surface formed by the inner surface of all the segments 31. Note that RA range = RB range = RC range = RD range = RE range = RF range = RG range = RH range. By the way, when the ratio (r / R) exceeds 0.99, only the circumferential end portions 37 and 38 of each segment 31 cannot be set in contact with the boot band 18, and the ratio (r / R) is 0. If it is less than 90, the gap between the central portion 36 of the inner diameter surface 32 of the segment 31 and the boot band 18 may become too large to contact the outer diameter surface of the boot band 18 at the central portion 36.

  Even in this case, the arc formed by the inner diameter surface 32 of all the segments 31 is made to coincide with the outer diameter arc of the reduced boot band 18, and the center of curvature of the inner diameter surface 32 of the segment 31 is the center of curvature. Since each segment 31 is moved radially inward so as to be displaced in the radial direction with respect to the center of the boot band 18, the same as in the case of using the boot band diameter reducing device shown in FIG. Has the effect of.

  By the way, the inner diameter surface 32 of each segment 31 may be worn as the number of times of caulking increases. Therefore, in order to improve the wear resistance of the inner diameter surface 32, the surface hardness is preferably about HRC45 to HRC65, for example. In order to set the surface hardness to about HRC45 to HRC65, a surface hardening process may be performed. The surface hardening treatment may be any treatment such as physical treatment or chemical treatment. For example, a shot peening process, a barrel process, or a thermosetting process can be employed, and these can be used alone or in combination.

  Moreover, you may make it give abrasion-resistant surface treatment. As the wear-resistant surface treatment, any one or more of dry plating, wet plating, melting treatment, thermal spraying, ion implantation, sulfurization treatment, chemical conversion treatment, surface heat treatment, and shot peening are performed, A surface with a small coefficient of friction is formed. This wear-resistant surface treatment includes a surface hardening treatment.

Here, among the above surface treatments, dry plating includes PVD treatment (physical vapor deposition) and CVD treatment (chemical vapor deposition). In PVD treatment, TiN, ZrN, CrN, TiC, TiCN, TiAlN, Al the _{2 O 3, DLC (Diamond like} Carbon) coating, such as, in the CVD process, TiC, TiN, TiCN, coatings such as TiCNO or _{TiC-TiN,, TiC-Al} 2 O 3, TiC-TiCNO, TiC-TiCN- A composite film such as TiN, TiC—TiCNO—TiN, TiC—TiCN—Al ₂ O ₃ , TiC—Al ₂ O ₃ —TiN may be formed. Wet plating includes electroplating and electroless plating, and types of plating include industrial chromium, electroless chromium, and composite plating.

The TiC / TiCN / Al ₂ O ₃ melting treatment includes cladding, alloying, glazing and the like. Thermal spraying includes gas spraying and electric spraying, and types of coating include chromium oxide, titanium oxide, and zirconia. Ion implantation includes high energy implantation and medium energy implantation. In the sulfuration treatment, a composite treatment using a layer containing molybdenum disulfide, which is a solid lubricant, as a film is effective. The chemical conversion treatment includes phosphate treatment, iron phosphate treatment, manganese phosphate treatment, chromate treatment and the like. The surface heat treatment includes surface quenching, carburizing and quenching, nitriding treatment, and sulfurating treatment.

  Among these treatments, dry plating, sulfurization treatment, and chemical conversion treatment are particularly effective in reducing the friction coefficient of the contact surface. On the other hand, in the heat treatment such as nitriding, the friction coefficient can be reduced and the wear resistance can be improved.

  In this way, the surface hardness of the boot band contact surface is set to HRC45 to HRC65, or the wear-resistant surface treatment is performed, so that the inner diameter surface of the segment is hard to be worn, and the durability is excellent. A stable caulking force can be exhibited.

  In the embodiment, the boot 10 is a resin boot using a thermoplastic elastomer material, but may be a rubber boot using chloroprene rubber or the like. Further, the boot band 18 may be made of aluminum or iron. In the constant velocity universal joint assembling method according to the present invention, a stable tightening force can be exerted on various types of boots and boot bands.

  As described above, the embodiment of the present invention has been described. However, the present invention is not limited to the above-described embodiment, and various modifications are possible. For example, the number of segments 31 to be used can be arbitrarily increased and decreased. The axial length (thickness) can be variously changed within a range in which the boot band 18 can be crimped. Further, the mechanism for reciprocating the segment 31 in the radial direction can be constituted by various mechanisms such as a cylinder mechanism, a ball screw mechanism, and a motor linear mechanism.

  As constant velocity universal joints, in addition to the above-mentioned fixed type constant velocity universal joints, a type having a mechanism that slides in the axial direction of the outer joint member (outer ring) (for example, a double offset type, a tripod type, a cross groove type, etc.) It can be applied to all constant velocity universal joints such as dynamic constant velocity universal joints).

FIG. 3 is a simplified view of a boot band diameter reducing device used in the constant velocity universal joint assembling method of the present invention. FIG. 6 is a simplified diagram showing a boot band reduced diameter state by the boot band reduced diameter apparatus. FIG. 3 is an enlarged simplified view of the main part of FIG. 2. FIG. 3 is a simplified diagram showing an outer diameter surface of a boot band after crimping by the boot band diameter reducing apparatus of FIG. 2. It is sectional drawing of a constant velocity universal joint. FIG. 6 is a simplified view of another boot band diameter reducing device used in the constant velocity universal joint assembling method of the present invention. FIG. 7 is a simplified view showing a boot band reduced diameter state by the boot band reduced diameter apparatus shown in FIG. 6. FIG. 8 is an enlarged simplified view of the main part of FIG. 7. FIG. 7 is a simplified diagram illustrating an outer diameter surface of a boot band after crimping by the boot band diameter reducing device of FIG. 6.

Explanation of symbols

10 Boot 18 Boot Band 18a Outer Diameter Surface 31 Segment 32 Inner Diameter Surface

Claims (9)

A constant velocity universal assembly method for mounting a boot with a reduced diameter bootband,
On the outer diameter side of the boot band, a plurality of segments whose inner surface is an arc surface are arranged in a ring shape along the circumferential direction, and the center of curvature of the inner surface of the segment is in the radial direction with respect to the center of the boot band. Each segment is moved inward in the radial direction so as to shift, and the boot band is reduced in diameter, and in this tightened state, the diameter is reduced on the arc surface formed by the inner diameter surface of all the segments. A constant velocity universal joint assembling method characterized by forming a circular arc surface of the outer diameter of the boot band.   The ratio (r / R) is 1.00 to 1.30, where R is the radius of the outer diameter surface of the boot band in the crimped state and r is the radius of curvature of the inner diameter surface of the segment. The method for assembling a constant velocity universal joint according to claim 1.   The ratio (r / R) is 0.90 to 0.99, where R is the radius of the outer diameter surface of the boot band in the crimped state and r is the radius of curvature of the inner diameter surface of the segment. The method for assembling a quick universal joint according to claim 1.   The constant velocity universal joint assembling method according to any one of claims 1 to 3, wherein the hardness of the boot band contact surface of the inner diameter surface of the segment is set to HRC45 to HRC65.   The constant velocity universal joint assembling method according to any one of claims 1 to 4, wherein the boot band contact surface is subjected to wear-resistant surface treatment.   The constant velocity universal joint assembling method according to claim 1, wherein the boot is made of resin.   The constant velocity universal joint assembling method according to any one of claims 1 to 5, wherein the boot is made of rubber.   The constant velocity universal joint assembling method according to any one of claims 1 to 7, wherein the boot band is made of aluminum.   The constant velocity universal joint assembling method according to claim 1, wherein the boot band is made of iron.

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