JP2011144850A - Constant velocity universal joint - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To secure the strength of a joined portion by removing a lubricant adhered to joining interfaces using laser joining which can improve reliability, while reducing cost. <P>SOLUTION: A constant velocity universal joint includes an outer joint metal member 3 having an opening at its one end and an inner joint member that transmits torque allowing angle displacement via balls with the outer joint member 3. The large diameter end 15 of a bellows-like plastic boot 12, which blocks an opening 13 of the outer joint member 3, is fitted and fixed by the laser joining externally onto the outer circumferential surface 14 of the opening 13 of the outer joint member 3, and the inner space between the outer joint member 3 and the boot 12 is filled with the lubricant. On the outer circumferential surface 14 of the opening 13 of the outer joint member 3, a projection 26 is arranged as a lubricant removing means, which prevents the lubricant from remaining on the joining interfaces between the opening 13 of the outer joint member 3 and the large diameter end 15 of the boot 12. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention is used in a power transmission system of automobiles and various industrial machines, and is provided with a boot that is incorporated in, for example, a drive shaft or a propeller shaft of an automobile and prevents foreign matter from entering from the outside of the joint or leakage of lubricant from the inside of the joint. It relates to a constant velocity universal joint.

  For example, there are two types of constant velocity universal joints that are used as means for transmitting a rotational force from an automobile engine to wheels at a constant velocity: a fixed constant velocity universal joint and a sliding constant velocity universal joint. Both of these constant velocity universal joints have a structure in which two shafts on the driving side and the driven side are connected so that rotational torque can be transmitted at a constant speed even if the two shafts have an operating angle.

  Since the drive shaft that transmits power from the engine of the automobile to the driving wheel needs to correspond to the angular displacement and axial displacement due to the change in the relative positional relationship between the engine and the wheel, the engine side (inboard side) ) And a fixed type constant velocity universal joint on the drive wheel side (outboard side), and both constant velocity universal joints are connected by an intermediate shaft.

  These sliding type constant velocity universal joints and fixed type constant velocity universal joints have a constant gap between the constant velocity universal joint and the intermediate joint in order to prevent the leakage of lubricant such as grease enclosed in the joint and to prevent foreign matter from entering from the outside of the joint. A structure in which a resin bellows-like boot is mounted between the shaft and the shaft is common (see, for example, Patent Document 1).

  As shown in FIG. 8, the boot 104 includes a large-diameter end 106 fastened and fixed to the outer peripheral surface of the opening 103 of the outer joint member 102 by a boot band 105, and an intermediate shaft extending from the inner joint member (not shown). The small-diameter end 109 fastened and fixed to the outer peripheral surface 107 by the boot band 108, the large-diameter end 106 and the small-diameter end 109 are connected, and the diameter is reduced from the large-diameter end 106 toward the small-diameter end 109. It is comprised with the bellows part 110 which can be expanded and contracted.

  FIG. 9 is an enlarged view showing a portion where the opening 103 of the outer joint member 102 and the large-diameter end 106 of the boot 104 are joined. As shown in the figure, an annular concave groove 111 is formed on the outer peripheral surface of the outer joint member 102, and the large-diameter end portion 106 of the boot 104 is bitten into the concave groove 111 by tightening with the boot band 105. The positioning of the large-diameter end 106 of 104 and the improvement of the sealing performance are intended.

Japanese Utility Model Publication No. 4-128536

  By the way, in the conventional constant velocity universal joint, in order to secure a stable sealing property by tightening and fixing with the boot band 105, it is necessary to securely fix the boot 104 with a predetermined tightening allowance. It is very difficult to carry out this simply and without causing variation among individuals.

  As described above, the reliability of the constant velocity universal joint is reduced due to the difficulty in securely fixing the boot 104 by tightening the boot band and the increase in the number of parts by using the boot band 105. This will increase the cost.

  In order to solve this problem, as shown in FIGS. 10 and 11, there is means for fixing the resin boot 114 to the metal outer joint member 112 by laser bonding. If this laser bonding is used, the boot band 105 (see FIG. 9) is not required, and the boot 114 is fixed without depending on the tightening of the boot band 105, so that the boot 114 can be surely and varied among individuals. It can be fixed without causing it.

  However, when the large-diameter end portion 116 of the boot 114 is assembled to the opening 113 of the outer joint member 112, the boot 114 is filled with a lubricant and the opening 114 of the outer joint member 112 is inserted into the large-diameter end of the boot 114. Since the portion 116 is externally fitted, there is a possibility that the lubricant is attached to the inner peripheral surface (laser bonding surface) of the large diameter end portion 116 of the boot 114. As described above, when the lubricant is present at the laser bonding interface between the inner peripheral surface of the large-diameter end portion 116 of the boot 114 and the outer peripheral surface of the opening 113 of the outer joint member 112, the bonding is insufficient at that portion. There was a possibility that the strength of laser bonding would decrease.

  The applicant removed the lubricant adhering to the inner peripheral surface of the large-diameter end portion 116 of the boot 114 with a cloth or the like before laser joining, but it is difficult to completely remove the lubricant. It was confirmed that the strength of laser bonding was lowered without bonding at the place where the mark remained.

  Therefore, the present invention has been proposed in view of the above-described problems, and the object of the present invention is to use a laser bonding that can improve reliability and reduce costs, and to apply a lubricant adhered to the bonding interface. An object of the present invention is to provide a constant velocity universal joint that can be removed to ensure the strength of a joint.

  As a technical means for achieving the above-mentioned object, the present invention allows an angular displacement between a metal outer joint member having an opening at one end and the outer joint member via a torque transmission member. And an inner joint member that transmits torque while the end of the resin bellows-like boot that closes the opening of the outer joint member is fitted on the outer peripheral surface of the opening of the outer joint member and fixed by laser bonding. And a constant velocity universal joint in which a lubricant is sealed in the inner space of the outer joint member and the boot, the outer joint between the outer peripheral surface of the opening of the outer joint member and the inner peripheral surface of the end of the boot. Lubricant removing means for preventing the lubricant from interposing at the joint interface between the opening of the member and the end of the boot is provided.

  In the present invention, the lubrication prevents the lubricant from intervening between the outer peripheral surface of the opening of the outer joint member and the inner peripheral surface of the end of the boot at the joint interface between the opening of the outer joint and the end of the boot. By installing the agent removing means, when assembling the end of the boot into the opening of the outer joint member, the inside of the boot is filled with a lubricant and the end of the boot is externally fitted into the opening of the outer joint member. When doing so, the lubricant adhering to the inner peripheral surface (laser bonding surface) of the end of the boot can be quickly removed. As a result, there is no lubricant at the laser bonding interface between the inner peripheral surface of the end of the boot and the outer peripheral surface of the opening of the outer joint member, and sufficient laser bonding is obtained and the strength of the laser bonding is improved. .

  As the lubricant removing means in the present invention, an annular protrusion formed along the circumferential direction on the outer peripheral surface of the opening of the outer joint member can be easily realized. When the lubricant removing means is a protrusion, the contact pressure between the inner peripheral surface of the boot and the outer joint member that contacts the inner peripheral surface of the boot is partially increased by partially increasing the outer diameter of the outer joint member. . Due to the difference in the contact pressure, the lubricant adhering to the laser bonding surface moves to a region where the contact pressure is lower. Therefore, by providing the protrusion on the outer peripheral surface of the opening of the outer joint member, it is possible to remove the lubricant adhering to the laser joining surface. The height of the protrusion with respect to the outer peripheral surface of the opening of the outer joint member is preferably 0.5 mm or more and 2.0 mm or less. If the height is set in such a range, the lubricant can be reliably removed. If this height is smaller than 0.5 mm, it is difficult to remove the lubricant reliably. If the height is larger than 2.0 mm, the large-diameter end of the boot is attached to the opening of the outer joint member. It becomes difficult to fit.

  As the lubricant removing means in the present invention, an annular concave groove formed along the circumferential direction on the outer peripheral surface of the opening of the outer joint member can be easily realized. When the lubricant removing means is a concave groove, the contact pressure between the inner peripheral surface of the boot and the outer joint member contacting the inner peripheral surface of the boot is partially reduced by partially reducing the outer diameter of the outer joint member. Become. Due to the difference in the contact pressure, the lubricant adhering to the laser bonding surface moves to a region having a lower contact pressure, that is, a concave groove. Therefore, the lubricant adhering to the laser joining surface can be removed by providing the concave groove on the outer peripheral surface of the opening of the outer joint member. The axial width dimension of the groove is preferably 1.0 mm or more. Thus, if the width dimension of a ditch | groove is set, a lubricant can be removed reliably. If the width dimension of the concave groove is smaller than 1.0 mm, it is difficult to reliably remove the lubricant.

  As the lubricant removing means in the present invention, it is easy to realize a cylindrical metal adapter interposed between the outer peripheral surface of the opening of the outer joint member and the inner peripheral surface of the end portion of the boot. It is desirable to interpose a resin-made bonding aid between the joint member and the outer peripheral surface of the opening. When the lubricant removing means is a metal adapter, by providing a protrusion or a concave groove on the surface of the metal adapter, a difference is caused in the contact pressure generated between the inner peripheral surface of the end of the boot and the metal adapter, The lubricant adhering to the laser bonding surface can be removed. In addition, if a resin-made bonding aid is interposed between the metal adapter and the outer joint member, when the metal adapter and the boot are laser-bonded, the bonding aid is caused by the heat transmitted from the heated metal adapter. It melts and foams, and the metal adapter and the outer joint member are laser-joined.

  The resin constituting the boot in the present invention is desirably a thermoplastic elastomer having laser transparency. By irradiating the laser transmissive resin with laser light during laser bonding, the laser light can pass through the resin and heat the outer joint member or the metal adapter.

  The fastening allowance between the end of the boot and the opening of the outer joint member in the present invention is preferably 0.5 mm or more and 3.0 mm or less. By setting the allowance within such a range, laser bonding can be realized under optimum conditions. If this tightening allowance is smaller than 0.5 mm, the external fitting state between the end portion of the boot and the opening portion of the outer joint member becomes loose, and it becomes difficult to obtain a good laser joining state. Further, if the tightening margin is larger than 3.0 mm, it is difficult to externally fit the end of the boot into the opening of the outer joint member.

  The laser bonding in the present invention is desirably performed by a semiconductor laser or a fiber laser. If a semiconductor laser or a fiber laser is used for laser bonding in this way, an existing laser beam irradiation apparatus can be used, and the cost can be reduced because of the reduction in equipment costs. Moreover, it is desirable that the laser beam irradiation method in laser bonding be a continuous type. In this way, efficient laser beam irradiation can be performed, and efficiency in laser bonding can be improved.

  The laser beam used in laser bonding in the present invention desirably has a circular spot size having a diameter of 2 mm or more, or a rectangular spot size having a long side of 2 mm or more. If it does in this way, a joined part can be heated stably at the time of laser joining. If the spot size diameter or long side is smaller than 2 mm, heating of the joint becomes unstable.

  According to the present invention, it is possible to prevent the lubricant from interposing between the outer peripheral surface of the opening portion of the outer joint member and the inner peripheral surface of the end portion of the boot at the joint interface between the opening portion of the outer joint member and the end portion of the boot. When the end of the boot is assembled to the opening of the outer joint member, the boot is filled with the lubricant and the end of the boot is inserted into the opening of the outer joint member. When externally fitting, the lubricant adhering to the inner peripheral surface (laser bonding surface) at the end of the boot can be quickly removed.

  As a result, there is no lubricant at the laser bonding interface between the inner peripheral surface of the end of the boot and the outer peripheral surface of the opening of the outer joint member, so that sufficient laser bonding is obtained and the strength of the laser bonding is improved. It is possible to provide a constant velocity universal joint with high reliability and long life.

In embodiment (protrusion) of this invention, it is a partial expanded sectional view which shows the opening part of an outer joint member, and the large diameter edge part of boots. In other embodiment (concave groove) of this invention, it is a partial expanded sectional view which shows the opening part of an outer joint member, and the large diameter edge part of boots. In other embodiment (metal adapter) of this invention, it is a partial expanded sectional view which shows the opening part of an outer joint member, and the large diameter edge part of boots. In an embodiment of the present invention, it is a longitudinal section showing the whole composition of a Rzeppa type constant velocity universal joint. It is a cross-sectional view which follows the AA line of FIG. It is a partial expanded sectional view for demonstrating the point which fixes the opening part of an outer joint member, and the large diameter edge part of boot by laser joining. It is a cross-sectional view for demonstrating the point which fixes the opening part of an outer joint member, and the large diameter edge part of boot by laser joining. It is sectional drawing which shows the conventional constant velocity universal joint. It is a partial expanded sectional view which shows the opening part of the outer joint member of the constant velocity universal joint of FIG. 8, and the large diameter end part of boots. It is sectional drawing which shows the constant velocity universal joint as a premise of this invention. It is a partial expanded sectional view which shows the opening part of the outer joint member of the constant velocity universal joint of FIG. 10, and the large diameter end part of boots.

  Embodiments of the constant velocity universal joint according to the present invention will be described in detail below. In the following embodiments, a sliding type constant velocity universal joint is provided on the engine side (inboard side) of the automobile, and a fixed type constant velocity universal joint is provided on the driving wheel side (outboard side). A structure that is incorporated in a drive shaft having a structure in which a joint is connected by an intermediate shaft, and that can transmit rotational torque at a constant speed even if the two axes on the driving side and the driven side are connected and the two axes take an operating angle. A Rzeppa type constant velocity universal joint, which is one of the fixed type constant velocity universal joints provided, will be exemplified.

  In the following embodiments, a case where the present invention is applied to a Rzeppa constant velocity universal joint will be described. However, the present invention is not limited to this, and the two shafts on the driving side and the driven side are connected to each other. Double offset type constant velocity universal joint, which is one of the sliding type constant velocity universal joints that has a structure that can transmit rotational torque at constant speed even when the operating angle is taken, and can also allow relative displacement in the axial direction. It is also applicable to.

  4 and 5, the Rzeppa constant velocity universal joint includes a cup-shaped outer joint in which arc-shaped track grooves 1 extending in the axial direction are formed at a plurality of locations in the circumferential direction of the spherical inner peripheral surface 2. An inner joint member 6 in which an arc-shaped track groove 4 extending in the axial direction in a pair with the track groove 1 of the member 3 and the outer joint member 3 is formed at a plurality of locations in the circumferential direction of the spherical outer peripheral surface 5; A ball 7 which is a plurality of torque transmitting members interposed between the track groove 1 of the joint member 3 and the track groove 4 of the inner joint member 6 and transmits the torque, and the spherical inner peripheral surface 2 of the outer joint member 3 A cage 9 that holds balls 7 accommodated in pockets 8 that are arranged between the inner joint member 6 and the spherical outer peripheral surface 5 and that are formed at equal intervals in the circumferential direction is a main component.

  One end of an intermediate shaft 11 is connected to the shaft hole 10 of the inner joint member 6 by spline fitting. The outer joint member 3 is formed of, for example, carbon steel typified by S53C and the like, and the intermediate shaft 11 is formed of carbon steel typified by, for example, S40C, and both of the outer joint member 3 and the intermediate shaft 11 are formed. In particular, it is formed of carbon steel that has been subjected to quenching treatment such as induction hardening. Further, the surfaces of the outer joint member 3 and the intermediate shaft 11 may be subjected to phosphate treatment for rust prevention.

  This type of constant velocity universal joint is made of resin between the outer joint member 3 and the intermediate shaft 11 in order to prevent leakage of lubricant such as grease enclosed in the joint and to prevent foreign matter from entering from the outside of the joint. A structure in which the bellows-like boot 12 is attached. As described above, by encapsulating the lubricant in the inner space of the outer joint member 3 and the boot 12, the inner shaft 11 is slid inside the joint when the intermediate shaft 11 rotates while taking an operating angle with respect to the outer joint member 3. Lubricity is ensured at a part, that is, a sliding part constituted by the outer joint member 3, the inner joint member 6, the ball 7 and the cage 9.

  The boot 12 is fixed to the outer peripheral surface 14 of the opening 13 of the outer joint member 3 by laser joining, and a large-diameter end 15 fixed to the outer peripheral surface 16 of the intermediate shaft 11 extending from the inner joint member 6 by laser joining. The small-diameter end portion 17, the large-diameter end portion 15, and the small-diameter end portion 17 are connected to each other, and the telescopic bellows portion 18 is reduced in diameter from the large-diameter end portion 15 toward the small-diameter end portion 17. Yes.

  As the resin constituting the boot 12, a thermoplastic polyester elastomer having laser transparency is suitable. This thermoplastic polyester elastomer is mainly composed of a polyester block copolymer comprising a high-melting crystalline polyester polymer segment (a) and a low-melting polymer segment (b). If a laser transmitting material is used in this way, the resin can be irradiated with laser light at the time of laser bonding, whereby the laser light can be transmitted and the bonded portion can be heated. The boot 12 can be manufactured, for example, by various blow molding methods such as extrusion blow, injection blow, press blow, or injection molding, but the production method is not particularly limited. .

  The high-melting-point crystalline polyester polymer segment (a) of the polyester block copolymer constituting the thermoplastic polyester elastomer is a polyester formed from an aromatic dicarboxylic acid or an ester-forming derivative thereof and an aliphatic diol, preferably Polybutylene terephthalate derived from terephthalic acid and / or dimethyl terephthalate and 1,4-butanediol. In addition, dicarboxylic acid components such as isophthalic acid, phthalic acid, naphthalene-2,6-dicarboxylic acid, or ester-forming derivatives thereof, and diols having a molecular weight of 300 or less, such as ethylene glycol, trimethylene glycol, pentamethylene Aliphatic diols such as glycol, hexamethylene glycol, neopentyl glycol and decamethylene glycol, alicyclic diols such as 1,4-cyclohexanedimethanol and tricyclodecane dimethylol, bis (p-hydroxy) diphenyl, bis (p Polyesters derived from aromatic diols such as -hydroxyphenyl) propane, 4,4'-dihydroxy-p-terphenyl, 4,4'-dihydroxy-p-quaterphenyl, or dicarboxylic acids thereof Ingredients and The diol component may be copolymerized polyesters used alone or in combination. Further, aliphatic dicarboxylic acids such as adipic acid and sebacic acid may be copolymerized. Furthermore, a trifunctional or higher polyfunctional carboxylic acid component, polyfunctional oxyacid component, polyfunctional hydroxy component, and the like can be copolymerized within a range of 5 mol% or less.

  The low-melting point polymer segment (b) of the polyester block copolymer constituting the thermoplastic polyester elastomer is an aliphatic polyether and / or an aliphatic polyester. Aliphatic polyethers include poly (ethylene oxide) glycol, poly (propylene oxide) glycol, poly (tetramethylene oxide) glycol, poly (hexamethylene oxide) glycol, copolymers of ethylene oxide and propylene oxide, poly (propylene oxide) Examples thereof include ethylene oxide addition polymers of glycol, copolymers of ethylene oxide and tetrahydrofuran, and the like. Examples of the aliphatic polyester include polycaprolactone, polyenantlactone, polycaprylolactone, polybutylene adipate, and polyethylene adipate. Among these aliphatic polyethers and / or aliphatic polyesters, poly (tetramethylene oxide) glycol, poly (propylene oxide) glycol ethylene oxide adducts, polycaprolactone, poly (polyethylene) are obtained from the elastic properties of the resulting polyester block copolymer. Butylene adipate and polyethylene adipate are preferred. The number average molecular weight of these low-melting polymer segments is preferably about 300 to 6000 in the copolymerized state. The copolymerization amount of the low melting point polymer segment (b) in the polyester block copolymer is preferably 10 to 80% by weight, more preferably 15 to 75% by weight.

  The thermoplastic polyester elastomer constituting the boot 12 can optionally contain various additives such as known antioxidants, light resistance agents, hydrolysis resistance inhibitors, coloring agents such as dyes, and flame retardants. However, the additive for suppressing the fraying noise forms a film of the additive on the surface of the material by laser light irradiation, thereby reducing the bonding strength. Therefore, any additive that exhibits a rubbing noise suppressing effect may be used as long as it can generally exhibit a lubricating action, for example, paraffin wax, microclostalline wax, polyethylene wax, montan wax, silicone oil, fatty acid, fatty acid. Amides, ester waxes, fatty alcohols, alcohol esters, fatty acid esters, polyether compounds, mineral oils, synthetic oils, vegetable oils, etc., widely used for rubbers and resins, and other uses, such as lubricants And the like used in the above.

  The procedure for fixing the large-diameter end 15 of the boot 12 described above to the outer peripheral surface 14 of the opening 13 of the outer joint member 3 by laser bonding is as follows.

  First, the large-diameter end 15 of the boot 12 is fitted on the outer peripheral surface 14 of the opening 13 of the outer joint member 3. At this time, the fastening allowance between the large-diameter end 15 of the boot 12 and the opening 13 of the outer joint member 3 is 0.5 mm or more and 3.0 mm or less. By setting the allowance within such a range, laser bonding can be realized under optimum conditions. If the tightening margin is smaller than 0.5 mm, the external fitting state between the large-diameter end portion 15 of the boot 12 and the opening portion 13 of the outer joint member 3 becomes loose, so that it is difficult to obtain a good laser joining state. It becomes. Further, if the tightening margin is larger than 3.0 mm, it is difficult to externally fit the large-diameter end 15 of the boot 12 to the opening 13 of the outer joint member 3.

  Laser joining between the large-diameter end 15 of the boot 12 and the outer peripheral surface 14 of the opening 13 of the outer joint member 3 uses a laser irradiator 24 as shown in FIGS. 6 illustrates the embodiment of FIG. 1, the same applies to the embodiments shown in FIGS. 2 and 3.

  The laser irradiator 24 includes an excitation source such as a semiconductor laser (wavelength: 808 nm + 904 nm) or a fiber laser, and has a bonding interface between the large-diameter end 15 of the boot 12 and the outer peripheral surface 14 of the opening 13 of the outer joint member 3. It has the irradiation part 25 which irradiates the focused laser beam L (output: 800 W). By adopting a semiconductor laser or a fiber laser for laser bonding in this way, an existing laser irradiation machine can be used, and the cost can be reduced due to the reduction in equipment costs.

  Further, the laser beam L is irradiated continuously by the laser irradiator 24. With this continuous laser light irradiation, efficient laser light irradiation can be performed, and efficiency in laser bonding can be improved. Note that the irradiation method of the laser light L is preferably a continuous method, but may be an intermittent method in which the laser light is irradiated intermittently (in a pulse manner). Further, the laser beam L has a circular spot size having a diameter of 2 mm or more, or a rectangular spot size having a long side of 2 mm or more. Thereby, a junction part can be heated stably at the time of laser joining. If the spot size diameter or long side is smaller than 2 mm, heating of the joint becomes unstable.

  The laser beam L from the laser irradiator 24 passes through the large-diameter end 15 of the boot 12 and is focused at the bonding interface between the large-diameter end 15 and the outer peripheral surface 14 of the opening 13 of the outer joint member 3. The bonding interface is heated in the state. This laser beam L is irradiated in a predetermined range in the joint axial direction (the direction of the arrow M in FIG. 6), and the outer joint in a state in which the boot 12 is externally fitted to the irradiation unit 25 of the fixedly arranged laser irradiation machine 24. By rotating the member 3 around the axis in the direction of the arrow N in FIG. 7 or by moving the irradiation unit 25 of the laser irradiator 24 in the circumferential direction of the boot 12 with respect to the outer joint member 3 in a fixed arrangement, The large-diameter end 15 of the boot 12 and the outer peripheral surface 14 of the opening 13 of the outer joint member 3 are joined over the entire circumference in a predetermined range in the joint axial direction. In the drawing, the irradiation unit 25 of the laser irradiator 24 is arranged outside the boot 12 and the laser beam is irradiated from the outside (boot side), but the irradiation unit 25 is connected to the outer joint member 3. It is also possible to irradiate the laser beam from the inside (outer joint member side) by being arranged inside the.

  The laser irradiator 24 irradiates the large-diameter end 15 of the boot 12 with a laser beam L having a high power density that can sufficiently heat the metal locally. The laser light L passes through the resin constituting the boot 12 and selectively heats the metal constituting the outer peripheral surface 14 of the opening 13 of the outer joint member 3. The resin in contact with the heated metal is rapidly heated above the decomposition temperature by the heat from the metal and partially melts. High-temperature and high-pressure conditions are realized by the bubbles generated by the decomposition, the high-temperature melt around the foam and the heated metal, and the metal and resin are joined by intermolecular force (van der Waals force) in the order of microns. A joined part is obtained.

  In this constant velocity universal joint, when the large-diameter end 15 of the boot 12 is assembled into the opening 13 of the outer joint member 3, the inside of the boot 12 is filled with a lubricant and the boot 13 is inserted into the opening 13 of the outer joint member 3. 12 large-diameter end portions 15 are externally fitted. Therefore, there is a possibility that the lubricant adheres to the inner peripheral surface (laser bonding surface) of the large-diameter end 15 of the boot 12. Thus, if the lubricant is present at the laser joining interface between the inner peripheral surface 21 of the large-diameter end 15 of the boot 12 and the outer peripheral surface 14 of the opening 13 of the outer joint member 3, the joint is insufficient at that portion. As a result, the strength of laser bonding may be reduced.

  Therefore, in the constant velocity universal joint in this embodiment, the opening of the outer joint member 3 is between the outer peripheral surface 14 of the opening 13 of the outer joint member 3 and the inner peripheral surface 21 of the large-diameter end 15 of the boot 12. Lubricant removing means for preventing the lubricant from intervening at the joint interface between 13 and the large-diameter end 15 of the boot 12 is provided.

  As this lubricant removing means, as shown in FIG. 1, an annular protrusion 26 formed on the outer peripheral surface 14 of the opening 13 of the outer joint member 3 along the circumferential direction is effective. The protrusion 22 is formed on the outer peripheral surface 14 of the outer joint member 3 on the end surface 20 side of the laser joining portion. When the lubricant removing means is the protrusion 26, the outer diameter of the outer joint member 3 is partially increased, so that the inner peripheral surface 21 of the large diameter end 15 of the boot 12 and the large diameter end 15 of the boot 12 are increased. The contact pressure with the outer joint member 3 that contacts the inner peripheral surface 21 is partially increased. Due to the difference in the contact pressure, the lubricant adhering to the laser bonding surface moves to a region where the contact pressure is lower. Therefore, by providing the protrusions 26 on the outer peripheral surface 14 of the opening 13 of the outer joint member 3, it is possible to remove the lubricant adhering to the laser joining surface.

  The height of the protrusion 26 with respect to the outer peripheral surface 14 of the opening 13 of the outer joint member 3 is 0.5 mm or more and 2.0 mm or less. If the height is set in such a range, the lubricant can be reliably removed. If the height is smaller than 0.5 mm, it is difficult to remove the lubricant reliably. If the height is larger than 2.0 mm, the large-diameter end 15 of the boot 12 is opened to the outer joint member 3. It becomes difficult to externally fit the portion 13.

  In addition, the applicant of the present invention has a tightening allowance between the large-diameter end 15 of the boot 12 and the opening 13 of the outer joint member 3 of 0.5, 1.0, 1.5, 2.0, 2.5, It was confirmed that all six types of 3.0 mm boots could be joined, and the joining force was 500 N or more. Although the illustrated protrusion 26 is one, the number thereof is arbitrary.

  As another lubricant removing means, as shown in FIG. 2, an annular groove 27 formed along the circumferential direction on the outer peripheral surface 14 of the opening 13 of the outer joint member 3 is also effective. The concave groove 27 is formed on the outer peripheral surface 14 of the outer joint member 3 on the end surface 20 side with respect to the laser joining portion. When the lubricant removing means is the concave groove 27, the outer diameter of the outer joint member 3 is partially reduced, whereby the inner peripheral surface 21 of the large-diameter end 15 of the boot 12 and the large-diameter end 15 of the boot 12. The contact pressure with the outer joint member 3 in contact with the inner peripheral surface 21 is partially reduced. Due to the difference in the contact pressure, the lubricant adhering to the laser bonding surface moves to a region having a lower contact pressure, that is, the concave groove 27. Therefore, by providing the concave groove 27 on the outer peripheral surface 14 of the opening 13 of the outer joint member 3, it is possible to remove the lubricant adhering to the laser joining surface.

  The axial width dimension of the concave groove 27 is 1.0 mm or more. Thus, if the width dimension of the concave groove 27 is set, the lubricant can be reliably removed. If the width dimension of the concave groove 27 is smaller than 1.0 mm, it is difficult to reliably remove the lubricant. Further, the depth of the concave groove 27 should be such that it does not affect the strength of the outer joint member 3.

  In addition, the applicant of the present invention has a tightening allowance between the large-diameter end 15 of the boot 12 and the opening 13 of the outer joint member 3 of 0.5, 1.0, 1.5, 2.0, 2.5, It was confirmed that all six types of 3.0 mm boots could be joined, and the joining force was 500 N or more. Although the illustrated concave groove 27 is one, the number is arbitrary.

  Furthermore, as other lubricant removing means, as shown in FIG. 3, it is interposed between the outer peripheral surface 14 of the opening 13 of the outer joint member 3 and the inner peripheral surface 21 of the large-diameter end 15 of the boot 12. A cylindrical metal adapter 28 is effective, and a resin-made bonding aid 29 is interposed between the metal adapter 28 and the outer peripheral surface 14 of the opening 13 of the outer joint member 3. When the lubricant removing means is the metal adapter 28, a protrusion or a concave groove is provided on the surface of the metal adapter 28, so that the gap between the inner peripheral surface 21 of the large-diameter end 15 of the boot 12 and the metal adapter 28 is increased. A difference is caused in the contact pressure generated in the laser beam, and the lubricant adhering to the laser bonding surface can be removed.

  First, the large-diameter end 15 of the boot 12 and the metal adapter 28 are fixed by laser bonding, and the metal adapter 28 to which the large-diameter end 15 of the boot 12 is fixed and the opening 13 of the outer joint member 3 Is fixed by laser bonding. At this time, laser bonding between the metal adapter 28 and the metal outer joint member 3 is facilitated by interposing the resin-made bonding aid 29 applied to the outer peripheral surface 14 of the opening 13 of the outer joint member 3. It becomes. Further, one end portion 28a of the metal adapter 28 is bent toward the boot side so that alignment with the large-diameter end portion 15 of the boot 12 is easy, and the other end portion 28b is positioned with respect to the opening portion 13 of the outer joint member 3. It is bent to the outer joint member side so that alignment is easy.

  In addition, the applicant of the present invention has a tightening allowance between the large-diameter end 15 of the boot 12 and the opening 13 of the outer joint member 3 of 0.5, 1.0, 1.5, 2.0, 2.5, It was confirmed that all six types of 3.0 mm boots could be joined, and the joining force was 500 N or more. As the metal adapter 28, one made of SUS304 and having a thickness of 1 mm was used, and as the joining aid 29, a polyester resin was used.

  In this constant velocity universal joint, between the outer peripheral surface 14 of the opening 13 of the outer joint member 3 and the inner peripheral surface 21 of the large-diameter end 15 of the boot 12, the opening 13 of the outer joint member 3 and the boot 12 are connected. Lubricant removing means for preventing the lubricant from intervening at the joint interface with the large-diameter end 15, for example, the protrusion 26, the concave groove 27, or the metal adapter 28, thereby providing the large-diameter end of the boot 12. When assembling 15 into the opening 13 of the outer joint member 3, when the large-diameter end 15 of the boot 12 is externally fitted into the opening 13 of the outer joint member 3 after filling the inside of the boot 12 with the lubricant, The lubricant adhering to the inner peripheral surface 21 (laser bonding surface) of the 12 large-diameter end portions 15 can be quickly removed. As a result, there is no lubricant at the laser bonding interface between the inner peripheral surface 21 of the large-diameter end 15 of the boot 12 and the outer peripheral surface 14 of the opening 13 of the outer joint member 3, and sufficient laser bonding is obtained. The strength of the laser bonding is improved.

  In the constant velocity universal joint in this embodiment, the end adjacent portion 19 extending from the large diameter end portion 15 of the boot 12 toward the bellows portion 18 is formed along the opening end face 20 of the outer joint member 3 (FIG. 1 to FIG. 3). By adopting such a shape, when the intermediate shaft 11 of the constant velocity universal joint takes an operating angle, on the contraction side of the bellows portion 18 of the boot 12, the end adjacent portion 19 of the boot 12 is formed on the outer joint member 3. Since it is guided by being pressed against the end face 20 of the opening, the stress directed in the direction of peeling the joint portion between the large-diameter end 15 of the boot 12 and the outer peripheral face 14 of the outer joint member 3 (radially outward) is relieved. can do. By this stress relaxation, it is possible to prevent the joint portion between the large-diameter end portion 15 of the boot 12 and the outer peripheral surface 14 of the outer joint member 3 from peeling off.

  The laser joining of the large-diameter end 15 of the boot 12 and the outer peripheral surface 14 of the opening 13 of the outer joint member 3 has been described above, but the small-diameter end of the boot 12 is the same as the large-diameter end 15 of the boot 12. The part 17 is also fixed to the outer peripheral surface 16 of the intermediate shaft 11 by laser bonding (see FIG. 2). Since the procedure of the laser joining is the same as that of the large-diameter end 15 of the boot 12, detailed description thereof is omitted.

  The present invention is not limited to the above-described embodiments, and can of course be implemented in various forms without departing from the gist of the present invention. It includes the equivalent meanings recited in the claims and the equivalents recited in the claims, and all modifications within the scope.

3 Outer joint member 6 Inner joint member 7 Torque transmission member (ball)
12 Boot 13 Opening of outer joint member 14 Outer peripheral surface of outer joint member 15 End of boot (large-diameter end)
21 Inner peripheral surface of boot end 26 Lubricant removing means (protrusion)
27 Lubricant removal means (concave groove)
28 Lubricant removal means (metal adapter)
29 Joining aid

Claims (12)

A metal outer joint member having an opening at one end, and an inner joint member that transmits torque while allowing angular displacement between the outer joint member and the outer joint member via the torque transmission member. An end portion of a resin bellows-like boot that closes the opening is fitted on the outer peripheral surface of the opening of the outer joint member and fixed by laser bonding, and a lubricant is sealed in the inner space of the outer joint member and the boot. A constant velocity universal joint,
Lubrication that prevents a lubricant from intervening at the bonding interface between the opening of the outer joint member and the end of the boot between the outer peripheral surface of the opening of the outer joint and the inner peripheral surface of the end of the boot. A constant velocity universal joint provided with an agent removing means.   The constant velocity universal joint according to claim 1, wherein the lubricant removing means is an annular protrusion formed along the circumferential direction on the outer peripheral surface of the opening of the outer joint member.   The constant velocity universal joint according to claim 2, wherein a height of the protrusion with respect to the outer peripheral surface of the opening of the outer joint member is 0.5 mm or more and 2.0 mm or less.   2. The constant velocity universal joint according to claim 1, wherein the lubricant removing means is an annular concave groove formed along the circumferential direction on the outer peripheral surface of the opening of the outer joint member.   The constant velocity universal joint according to claim 4, wherein an axial width dimension of the concave groove is 1.0 mm or more.   The lubricant removing means is a cylindrical metal adapter interposed between the outer peripheral surface of the opening of the outer joint member and the inner peripheral surface of the end of the boot, and the outer periphery of the opening of the metal adapter and the outer joint member The constant velocity universal joint according to claim 1, wherein a bonding aid made of resin is interposed between the surface and the surface.   The constant velocity universal joint according to any one of claims 1 to 6, wherein the resin constituting the boot is a thermoplastic elastomer having laser permeability.   The constant velocity universal joint according to any one of claims 1 to 7, wherein a fastening margin between an end of the boot and an opening of the outer joint member is 0.5 mm or more and 3.0 mm or less.   The constant velocity universal joint according to any one of claims 1 to 8, wherein the laser bonding is performed by a semiconductor laser or a fiber laser.   The constant velocity universal joint as described in any one of Claims 1-9 which made the laser beam irradiation system in the said laser joining continuous.   The constant velocity universal joint according to any one of claims 1 to 10, wherein a laser beam used in the laser bonding has a circular spot size having a diameter of 2 mm or more.   The constant velocity universal joint according to any one of claims 1 to 10, wherein the laser beam used in the laser bonding has a rectangular spot size having a long side of 2 mm or more.

Images