JP4984149B2 - Fixed type constant velocity universal joint - Google Patents

Description

  The present invention relates to a constant velocity universal joint used in an automobile or the like, and more particularly to a fixed type constant velocity universal joint used in a steering device.

  Constant velocity universal joints are roughly classified into two types: fixed type constant velocity universal joints capable of only angular displacement and sliding type constant velocity universal joints capable of angular displacement and axial displacement (plunging). Are properly used according to the purpose. As a fixed type constant velocity universal joint, a so-called Zepper type or a bar field type (hereinafter referred to as “BJ”) and an undercut free type (hereinafter referred to as “UJ”) are widely known. .

  The above-mentioned fixed type constant velocity universal joints such as BJ and UJ are used, for example, in an automobile steering device (handle operation unit) as shown in FIG. This steering device will be described first.

  A steering device 150 shown in FIG. 12A includes a steering wheel (handle) 156, a steering column shaft 152, a steering shaft 154, a steering gear box 158, a knuckle arm 153 attached to a wheel 155, and a tie rod 159. . The steering wheel 156 and the steering gear box 158 are connected by a steering column shaft 152 and a steering shaft 154, and the steering gear box 158 and the knuckle arm 153 are connected by a tie rod 159. Note that the steering column shaft 152 and the steering shaft 154 are connected at different angles by one or a plurality of steering joints 151. In the steering device 150 of FIG. 12A, the steering column shaft 152 and the steering shaft 154 are one. The two shaft joints 151 are connected.

  In such a steering device 150, the rotational motion of the steering wheel 156 is transmitted to the steering gear box 158 via the steering column shaft 152 and the steering shaft 154 and converted into a reciprocating motion. As a result, the tie rod 159 reciprocates and the position of the knuckle arm 153 changes, so that the wheel 155 rotates and the traveling direction of the vehicle body can be changed.

  On the other hand, when the steering shaft 154 cannot be arranged in a straight line as in the steering device 150 shown in FIG. 12A due to the vehicle space, the steering shaft as in the steering device 160 shown in FIG. One or a plurality of shaft couplings 151 (one in the figure) are arranged between 154, and the state between the steering column shaft 152 and the steering shaft 154 is bent by the shaft coupling 151 as in FIG. Thus, an accurate rotational motion can be transmitted to the steering gear box 158. Note that FIG. 12B shows a horizontal arrow view of FIG. 12A, but as shown by the symbol α in this figure, the bending angle of the shaft coupling 151 is large exceeding 30 °. The angle can also be set.

  Now, the above-mentioned fixed type constant velocity universal joint is adopted as the shaft joint 151 of the steering apparatus shown in FIG.

  The fixed type constant velocity universal joint has an outer ring in which a plurality of linear track grooves are formed on a spherical inner peripheral surface, and a plurality of curved track grooves that are paired with the track grooves of the outer ring on a spherical outer peripheral surface. A plurality of balls interposed between the outer ring track groove and the inner ring track groove, and a cage that is disposed between the outer joint member and the inner joint member and holds the ball. It is a structure provided.

  Such a fixed type constant velocity universal joint has a gap between a track groove of the outer ring and a track groove of the inner ring through a ball in terms of function and processing surface, and the spherical inner peripheral surface of the outer ring and the cage There are also gaps between the spherical outer peripheral surface of the inner ring and between the spherical outer peripheral surface of the inner ring and the spherical inner peripheral surface of the cage. These gaps are fixed in either the outer ring or the inner ring in the neutral state of the joint (with no operating angle), and the other moves in the axial direction (axial direction) or radial direction (direction perpendicular to the axial direction). This means the amount of movement at the time of movement, and is called an axial gap or a radial gap depending on the movement direction. These gaps greatly affect the circumferential play (rotational backlash) between the outer ring and the inner ring, and the larger the gap, the larger the gap. Such a fixed type constant velocity universal joint cannot be used in a place where rotation backlash is disliked like the automobile steering apparatus shown in FIG. Therefore, a fixed type constant velocity universal joint capable of preventing rotation backlash is used for the shaft coupling 151 shown in FIG. An example of this fixed type constant velocity universal joint is shown in FIG.

  The fixed type constant velocity universal joint 101 has a structure in which an inner member 109, a ball 113, and a cage 110 are accommodated in an outer ring 102 having an opening at one end. A plurality of curved track grooves 104 are formed on the spherical inner peripheral surface 103 of the outer ring 102. The inner member 109 includes an inner ring 105 and a shaft 108 that is spline-fitted to the inner ring 105 and is prevented from coming off by a circlip 125, and the tip of the shaft 108 protrudes toward the shaft opposite insertion side of the inner ring 105. A plurality of curved track grooves 107 that are paired with the track grooves 104 of the outer ring 102 are formed on the spherical outer peripheral surface 106 of the inner ring 105, and the track grooves 104 of the outer ring 102 and the track grooves 107 of the inner ring 105 are formed. A plurality of balls 113 are interposed therebetween. The ball 113 is held in a pocket 114 of the cage 110 disposed between the outer ring 102 and the inner ring 105.

  A concave portion 124 is formed at the tip of the shaft 108, and a plunger unit 117 is fitted into the concave portion 124 by press fitting.

  This plunger unit 117 serves as a pressing member having a pressing portion 121 at the tip (end on the outer ring opposite opening side) in a bottomed cylindrical case 119 having an opening at the end on the outer ring opposite opening side. A ball 120 and a compression coil spring (hereinafter referred to as a spring) 118 serving as an elastic member that allows the ball 120 to protrude and retract from the case 119 by an elastic force are accommodated. Further, the spring 118 urges the pressing portion 121 of the ball 120 in a direction of projecting from the opening of the case 119 with its elastic force. An enlarged sectional view of the plunger unit 117 is shown in FIG.

  A concave spherical receiving member 122 facing the tip of the shaft 108 is attached to the outer ring opposite opening side end portion of the inner peripheral surface 112 of the cage 110, and the spherical surface portion on the plunger unit side of the receiving member 122 is It functions as a receiving portion 123 that receives a pressing force from the pressing portion 121.

  As described above, the receiving portion 123 receives the pressing force from the pressing portion 121, so that the gap between the track groove 104 of the outer ring 102 and the track groove 107 of the inner ring 105 is clogged with a preload, thereby The rotation backlash described above can be prevented.

  As shown in FIG. 11, which is an enlarged cross-sectional view of the main part of the plunger unit 117 shown in FIGS. 9 and 10, the inner diameter of the portion of the recessed portion 124 on the outer ring opening side a is on the outer ring opening side a of the plunger unit 117. It is formed smaller than the outer diameter of the part. Thereby, the site | part in the outer ring | wheel opening part side a of the plunger unit 117 can be reliably press-fitted in the site | part in the outer ring | wheel opening part side a of the recessed part 124. FIG. In FIG. 11, the movement due to the elasticity of the spring 118 is indicated by a two-dot chain line.

  Also, the inner diameter of the portion of the recessed portion 124 on the outer ring opposite opening side b is larger than the inner diameter of the portion of the recessed portion 124 on the outer ring opening side a, and the outer diameter of the portion of the case 119 on the outer ring opening side b. The gap 130 is provided between the inner peripheral surface of the portion on the outer ring opposite opening side b of the recessed portion 124 and the outer peripheral surface of the portion on the outer ring opposite opening side b of the case 119. . In this case, when the plunger unit 117 is fitted into the recessed portion 124 by press-fitting, the diameter of the portion on the outer ring opening side a of the case 119 is reduced without reducing the diameter of the portion on the outer ring opposite opening side b of the case 119. And can be press-fitted into the recessed portion 124. As a result, the movement of the ball 120 as the pressing member is not hindered by reducing the diameter of the portion of the case 119 on the outer ring opposite opening side b.

Further, a clearance m is provided on the inner peripheral surfaces of the ball 120 and the case 119 so that the ball 120 can easily project and retract (see Patent Document 1).
Japanese Patent Laid-Open No. 2005-214297

  In the case of the fixed type constant velocity universal joint described in Patent Document 1, the gap between the track groove 104 of the outer ring 102 and the track groove 107 of the inner ring 105 is clogged with a preload applied by the plunger unit. Thus, the rotational backlash already described can be prevented.

  In addition, since a gap 130 is provided between the inner peripheral surface of the portion on the outer ring opposite opening portion side b of the recessed portion 124 and the outer peripheral surface of the portion on the outer ring opposite opening portion side b of the case 119, preloading is performed in the plunger unit 117. The protrusion and retraction movement of the ball 120 involved in the application of the ball is not hindered.

  However, in the case of the fixed type constant velocity universal joint described in Patent Document 1, since the cross section of the case 119 of the plunger unit 117 is circular, the plunger unit 117 is fitted into the recessed portion 124 of the shaft 108 by press fitting. In doing so, the diameter of the case 119 must be reduced over the entire circumference, and as a result, the force required for press-fitting the plunger unit 117 increases, resulting in a problem that workability of the press-fitting operation is reduced.

  In addition, when the pressure input of the plunger unit 117 is large as described above, the case 119 of the plunger unit 117 and the recessed portion 124 of the shaft 108 may be deformed or damaged by the press-fitting load.

  The present invention has been made in view of the above circumstances, and it is possible to provide a fixed type constant velocity universal joint that can not only relieve the pressure input required when the plunger unit is press-fitted but also can stably fix the plunger unit. The purpose is to provide.

The fixed type constant velocity universal joint of the present invention for solving the above-mentioned problems is an outer member in which a plurality of curved track grooves are formed on a spherical inner peripheral surface, and the outer member on a spherical outer peripheral surface. An inner member formed with a plurality of curved track grooves that are paired with the track grooves, and a plurality of balls interposed between the track grooves of the outer member and the track grooves of the inner member; A plunger unit that is disposed between the outer member and the inner member and includes a cage that holds the ball and has a pressing portion that applies an elastic pressing force in the axial direction is formed on the inner member. A fixed type constant velocity universal joint that is fitted in a recessed portion and is provided with a receiving portion for receiving a pressing force from the pressing portion on the cage, wherein the plunger unit has a bottomed cylindrical shape having an opening at one end. In the case, the pressing portion having the pressing portion at the tip And an elastic member that urges the pressing portion of the pressing member in a direction to protrude from the opening of the case with an elastic force, and the pressing member protrudes on the outer peripheral surface of the case A portion excluding the retreating axial range is press-fitted into the recessed portion of the inner member, and a protrusion that extends at least over the entire axial length of the press-fitting portion is provided .

  Thus, when the plunger unit has a protrusion extending in the fitting direction on the outer peripheral surface thereof, when the plunger unit is fitted into the recessed portion of the inner member by press-fitting, the plunger unit has a periphery of the outer peripheral surface. Since it is possible to press-fit by reducing the diameter of only the portion having the ridge, rather than reducing the diameter over the entire circumference in the direction, the pressure input of the plunger unit can be eased.

  It is desirable to provide the protrusions at a plurality of locations in the circumferential direction of the plunger unit.

  In this case, after the plunger unit is fitted into the recessed portion of the inner member, the plurality of protrusions are in close contact with the recessed portion, and the plunger unit can be stably fixed at the recessed portion. It is possible to prevent rattling at the recessed portion.

  The above actions and effects become more prominent by providing the protrusions at equal intervals along the circumferential direction of the plunger unit.

  The reason for this is that when a plurality of protrusions are provided at equal intervals along the circumferential direction of the plunger unit, when the plunger unit is press-fitted into the recessed portion of the inner member, the plunger unit is provided at equal intervals along the circumferential direction. The protruding ridge is in close contact with the recessed portion. Thereby, since the plunger unit receives the drag force from the recessed portion evenly through the protruding portion, it can be fixed in a balanced manner at the recessed portion. As a result, it is possible to reliably prevent the plunger unit from rattling at the recessed portion.

  The above actions and effects are preferably realized by setting the number of protrusions to three and providing these protrusions at equal intervals along the circumferential direction. In this case, since the plunger unit is only provided with the minimum protrusions, the time and manufacturing cost required for molding the plunger unit can be reduced.

  The plunger unit has a bottomed cylindrical case having an opening at one end, a pressing member having the pressing portion at the tip, and an elastic member that allows the pressing member to protrude and retract from the case by elastic force. And the pressing portion of the pressing member can be urged in a direction to protrude from the opening of the case with the elastic force of the elastic member.

  Here, the “pressing member having a pressing portion at the tip” means that the pressing member has a pressing portion at the end on the side opposite to the case opening. Since the plunger unit having the above structure has a structure in which the pressing member and the elastic member are accommodated in the case, the entire structure can be made compact.

  In the plunger unit having the above-described shape, it is preferable to press-fit a portion of the outer peripheral surface of the case excluding an axial range in which the pressing member protrudes and retracts into the recessed portion of the inner member.

  In this case, when the plunger unit is press-fitted into the recessed portion of the shaft, the portion of the axial range where the pressing member protrudes and retracts is reduced in diameter on the outer peripheral surface of the case of the plunger unit, so that the pressing member does not protrude. The pressing portion at the tip of the pressing member can stably apply a pressing force to the receiving portion without hindering the retreating movement. As a result, backlash of the constant velocity universal joint can be reliably prevented.

  Furthermore, in the plunger unit having the above-described shape, the protruding portion can be provided over the entire axial length of the press-fit portion.

  Even in this case, it is possible to sufficiently obtain the action and effect of the protrusions according to the present invention. In addition, since no protrusion is provided in any part other than the press-fitting part of the plunger unit, it is possible to reduce the time and manufacturing cost required for molding the case of the plunger unit.

  In the fixed type constant velocity universal joint of the present invention, the plunger unit has a protrusion on the outer peripheral surface thereof. For this reason, when the plunger unit is press-fitted into the recessed portion of the inner member, the plunger unit does not reduce the diameter over the entire circumference in the circumferential direction of the outer peripheral surface, but only reduces the diameter of the portion having the protrusion. Can be press-fitted. Thereby, since the pressure input of a plunger unit can be relieve | moderated, the assembly | attachment property (easy to assemble and efficiency) of a joint can be improved. In addition, since the pressure input of the plunger unit is relaxed, it is possible to prevent the case of the plunger unit and the recessed portion of the shaft from being deformed or damaged by an excessive press-fitting load.

  Hereinafter, an embodiment in which the present invention is applied to a fixed type constant velocity universal joint used in a steering apparatus for an automobile will be described with reference to the accompanying drawings.

  The fixed type constant velocity universal joint used for the steering device of an automobile has a structure capable of preventing circumferential backlash (rotational backlash) between the outer joint member and the inner joint member as described above. ing. Note that the details of the steering device have already been described with reference to FIG.

  FIG. 4 shows a first embodiment of the present invention. The fixed type constant velocity universal joint 1 has a structure in which an inner member 9, a ball 13, and a cage 10 are accommodated in an outer ring 2 which is an outer member having an opening at one end. A plurality of curved track grooves 4 are formed on the spherical inner peripheral surface 3 of the outer ring 2. The inner member 9 includes an inner ring 5 that is an inner joint member, and a shaft 8 that is a shaft member that is spline-fitted to the inner ring 5, and the tip portion of the shaft 8 projects toward the outer ring opposite opening of the inner ring 5. Yes. A plurality of curved track grooves 7 that are paired with the track grooves 4 of the outer ring 2 are formed on the spherical outer peripheral surface 6 of the inner ring 5, and the track grooves 4 of the outer ring 2 and the track grooves 7 of the inner ring 5 A plurality of balls 13 interposed therebetween are interposed. This ball 13 is held in a pocket 14 of the cage 10 disposed between the outer ring 2 and the inner ring 5.

  A concave groove 15 is formed on the inner circumferential surface of the inner ring 5 on the outer ring opposite opening side, and a concave groove 16 is formed on a portion of the outer circumferential surface of the shaft 8 facing the concave groove 15 of the inner ring 5. A circlip 25 is interposed between the groove 15 and the groove 16. The circlip 25 can prevent the shaft 8 from coming off from the inner ring 5.

  The outer peripheral surface 11 of the cage 10 is spherically fitted to the spherical inner peripheral surface 3 of the outer ring 2, and the spherical inner peripheral surface 12 of the cage 10 is spherically fitted to the spherical outer peripheral surface 6 of the inner ring 5.

The center of the spherical inner peripheral surface 3 of the outer ring 2 and the center of the spherical outer peripheral surface 6 of the inner ring 5 coincide with the joint center O. On the other hand, the center O ₁ of the track groove 4 of the outer ring 2 and the center O ₂ of the track groove 7 of the inner ring 5 are offset by an equal distance in the opposite directions in the axial direction with respect to the joint center O. In this case, O ₁ is offset to the outer ring opening side, and O ₂ is offset to the outer ring opposite opening side. For this reason, the ball track formed by the pair of track grooves (4, 7) has a wedge shape that expands from the side opposite to the opening of the outer ring 2 toward the opening. The curved track groove 4 of the outer ring 2 and the curved track groove 7 of the inner ring 5 are curved over the entire length in the axial direction. A fixed type constant velocity universal joint having such a structure is It is called a field type fixed type constant velocity universal joint (BJ).

  Further, as shown in FIG. 5, in the fixed type constant velocity universal joint 1, the ball 13 guided to the cage 10 always has two operating angles θ, regardless of the operating angle θ between the outer ring 2 and the inner ring 5. It is maintained in a plane perpendicular to the bisector, thereby ensuring constant velocity of the joint.

  Now, in the fixed type constant velocity universal joint used for a steering shaft of an automobile, a recessed portion 24 is formed at the tip portion of the shaft 8 as in this embodiment, and the plunger unit 17 is press-fitted into the recessed portion 24. It is mated.

  The plunger unit 17 serves as a pressing member having a pressing portion 21 at the tip (end on the side opposite to the outer ring opening) in a bottomed cylindrical case 19 having an opening on the end on the outer ring opposite opening side. A ball 20 and a compression coil spring (hereinafter referred to as a spring) 18 as an elastic member that allows the ball 20 to protrude and retract from the case 19 by an elastic force are accommodated. Here, “the ball 20 as a pressing member having the pressing portion 21 at the tip” means that the ball 20 has the pressing portion 21 at the end on the side opposite to the case opening. Further, the spring 18 urges the ball 20 in the direction in which the ball 20 protrudes from the opening of the case 19 with its elastic force. An enlarged sectional view of the plunger unit 17 is shown in FIG.

  A stepped locking portion 26 having a locking surface on the side opposite to the outer ring opening is formed on the inner circumferential surface 12 of the cage 10 on the outer ring opposite opening side. The engaging portion 26 is attached by engaging a concave spherical receiving member 22 facing the tip portion of the shaft 8, and the spherical portion of the receiving member 22 on the plunger unit side receives a pressing force from the pressing portion 21. It functions as the receiving part 23 to receive.

  As described above, the receiving portion 23 receives the pressing force from the pressing portion 21, so that the gap between the track groove 4 of the outer ring 2 and the track groove 7 of the inner ring 5 is clogged with a preload. Rotation backlash can be prevented.

  Further, when the plunger unit 17 has the above-described shape, since the pressing member and the elastic member are accommodated in the case 19, the entire structure can be made compact.

  As shown in FIG. 3, which is an enlarged cross-sectional view of the main part of the plunger unit 17, the inner diameter of the portion of the recessed portion 24 on the outer ring opening side a is larger than the outer diameter of the portion of the plunger unit 17 on the outer ring opening side a. Small and molded. Thereby, the site | part in the outer ring | wheel opening part side a of the plunger unit 17 can be reliably press-fitted in the site | part in the outer ring | wheel opening part side a of the recessed part 24. FIG. In FIG. 3, the movement due to the elasticity of the spring 18 is indicated by a two-dot chain line.

  The plunger unit 17 has an inner diameter of a portion of the concave portion 24 on the side opposite to the outer ring opening b, that is, a portion in the axial range in which the ball 20 as a pressing member protrudes and retracts, on the outer ring opening side of the concave portion 24. A portion of the recessed portion 24 on the outer ring opposite opening side b is formed by molding larger than the inner diameter of the portion in a and larger than the outer diameter of the portion on the outer ring opposite opening side b of the plunger unit 17. A gap 30 is provided between the inner peripheral surface of the case 19 and the outer peripheral surface of the portion of the outer ring opposite opening b of the case 19.

  In this case, when the plunger unit 17 is fitted into the recessed portion 24 by press fitting, the plunger unit 17 does not reduce the diameter of the portion on the outer ring opposite opening portion side b of the case 19, and the outer ring opening portion side a of the case 19. Since only the portion excluding the axial direction range in which the ball 20 that is a pressing member protrudes and retracts can be reduced in diameter and press-fitted into the recessed portion 24, the ball 20 does not hinder the protrusion and retraction movement of the ball 20. The tip pressing portion 21 can stably apply a pressing force to the receiving portion 23. As a result, the already described backlash can be reliably prevented.

  Further, a clearance m is provided on the inner peripheral surfaces of the ball 20 and the case 19 so that the ball 20 can easily protrude and retract.

  Now, in this embodiment, as shown in FIG. 2 which is XX sectional drawing of the plunger unit 17 shown in FIG.1, FIG4 and FIG.1, 3 extended over the axial direction full length of the case 19 of the plunger unit 17. Two protrusions 31 are provided at equal intervals along the circumferential direction. In addition, illustration of the spring 18 was abbreviate | omitted in FIG.

  Thus, when the protrusion is provided on the outer peripheral surface of the plunger unit 17, when the plunger unit is fitted into the recess 24 of the shaft 8 by press fitting, only the protrusion 31 of the plunger unit 17 is reduced in diameter. Can be press-fitted.

  In this case, as in the prior art, when the plunger unit 17 is fitted into the recessed portion 24 of the shaft 8 by press fitting, the plunger unit 17 does not reduce its diameter over the entire circumference in the circumferential direction of its outer peripheral surface. It is possible to press-fit by reducing the diameter of only the portion having the portion 31. Thereby, the pressure input of the plunger unit 17 is relieved and the assembly | attachment property (easy to assemble and efficiency) of a joint can be improved. Further, since the pressure input of the plunger unit 17 is relaxed, it is possible to prevent the case 19 of the plunger unit 17 and the recessed portion 24 of the shaft 8 from being deformed or damaged by an excessive press-fitting load.

  As shown in FIG. 1, after the plunger unit 17 is fitted into the recessed portion 24 by press-fitting, a protrusion on the outer ring opening side a of the plunger unit 17, that is, at the press-fitting portion of the plunger unit 17. 31 is in close contact with the recessed portion 24 (B in the figure). In the present embodiment, a gap 32 is provided between the portion where the protruding portion 31 is not provided and the recessed portion 24 in the portion on the outer ring opening side a on the outer peripheral surface of the plunger unit 17 (A in the drawing). . However, the gap 32 is not necessarily required, and the entire portion on the outer ring opening side a may be brought into close contact with the recessed portion 24 on the outer peripheral surface of the plunger unit 17.

  The number of the protrusions 31 provided in the circumferential direction is not particularly limited as long as the above-described effects and effects of the present invention can be sufficiently obtained, but a plurality of protrusions 31 as in the present embodiment. preferable. Thus, when the number of the protrusions 31 is plural, after the plunger unit 17 is fitted to the recess 24 of the shaft 8, the plurality of protrusions 31 are brought into close contact with the recess 24, so that the plunger unit 17 is recessed. The portion 24 can be stably fixed without rattling.

  In the present embodiment, the above-described actions and effects become more prominent by providing the plurality of protrusions 31 at regular intervals along the circumferential direction.

  The reason for this is that, by providing a plurality of protrusions 31 at equal intervals along the circumferential direction of the plunger unit 17, the plunger unit 17 is fitted into the recessed portion 24 of the shaft 8, and then the plunger unit 17 is circumferentially moved. The protrusions 31 provided at equal intervals along the recess closely contact the recess 24, whereby the plunger unit 17 receives the drag force from the recess 24 evenly via the protrusion 31, so that the recess 24 It is fixed with a good balance. As a result, it is possible to reliably prevent the plunger unit 17 from rattling at the recessed portion 24.

  Furthermore, in this embodiment, the above-mentioned operation and effect are obtained by providing three protrusions 31 on the outer peripheral surface of the case 19 of the plunger unit 17 at equal intervals (120 ° intervals) along the circumferential direction. Therefore, the protrusion 31 provided on the plunger unit 17 is the minimum necessary, and the time and manufacturing cost required for molding the plunger unit 17 can be reduced.

  FIG. 6 shows a second embodiment of the present invention. In the present embodiment, parts having the same portions, functions, and forms as those in the first embodiment shown in FIG. 4 are denoted by the same reference numerals, and detailed description thereof is omitted.

  In the fixed type constant velocity universal joint 41 of the present embodiment, the plunger unit 57 is fitted into the recessed portion 24 formed at the distal end portion of the shaft 8 by press fitting.

  This plunger unit 57 includes a ball 60 as a pressing member having a pressing portion 61 at the tip in a bottomed cylindrical case 59 having an opening at the end on the side opposite to the outer ring, and an elastic force. Thus, a compression coil spring (hereinafter referred to as a spring) 58 is accommodated as an elastic member that can protrude and retract from the case 59. Further, the spring 58 urges the ball 60 in the direction in which the ball 60 protrudes from the opening of the case 59 with its elastic force. An enlarged sectional view of the plunger unit 57 is shown in FIG.

  In the present embodiment, as shown in FIG. 8 which is a YY sectional view of the plunger unit 57 shown in FIGS. 6, 7, and 6, the outer peripheral surface of the case 59 is on the outer ring opening side a serving as a press-fitting portion. Three ridges 71 are provided at equal intervals along the circumferential direction, extending over the entire axial range of the region excluding the region in which the ball 60 as a pressing member protrudes and retracts. In FIG. 8, the illustration of the spring 58 is omitted.

  Since the operation and effect in this case are the same as the operation and effect described in the first embodiment shown in FIG. 1, detailed description thereof is omitted. However, in the present embodiment, as shown in FIG. 7, the axial direction of the portion of the outer ring opening side a that becomes the press-fitting portion into the recessed portion 24 is not the entire axial length of the case 59 but the outer peripheral surface of the case 59. Since it is provided only over the entire length of the range, the time and manufacturing cost required for forming the case 59 can be reduced.

  Although the embodiments of the present invention have been described above, the embodiments given here are merely examples, and all modifications can be made within the scope of the claims.

  For example, in this embodiment, there are three ridges, and these ridges are provided at equal intervals (120 ° intervals) along the circumferential direction of the case of the plunger unit. However, the number of ridges is six or eight, and these ridges are equally spaced along the circumferential direction of the case of the plunger unit (if there are six ridges, 60 ° intervals, If it is eight, it can also be provided at 45 ° intervals).

  Moreover, in embodiment mentioned here, it was set as the structure which press-fits only the site | part in the outer ring | wheel opening part side of a plunger unit, However, It is good also as a structure which press-fits the axial direction full length of a plunger unit. However, when the entire length in the axial direction of the plunger unit is press-fitted, the length in the axial direction of the plunger unit that must be press-fitted becomes longer than when only the portion on the outer ring opening side of the plunger unit is press-fitted. Power also increases. Therefore, it is preferable that the plunger unit has a structure in which only a portion on the outer ring opening side of the plunger unit is press-fitted as in the embodiment described here.

  In addition, the present invention is a bar field type fixed type constant velocity in which the curved track groove of the outer ring and the curved track groove of the inner ring are curved over the entire length in the axial direction, as in the embodiment described here. Not only universal joints (BJ), the outer and inner ring track grooves are each composed of a curved track groove and a straight track groove parallel to the axis. (UJ) can also be applied.

FIG. 5 is an enlarged cross-sectional view of the plunger unit shown in FIG. 4 according to the first embodiment of the present invention. It is sectional drawing of the XX part of the plunger unit shown in FIG. It is a principal part expanded sectional view of the plunger unit shown in FIG. It is sectional drawing which shows the 1st Embodiment of this invention. It is sectional drawing when the fixed type constant velocity universal joint shown in FIG. 4 takes the operating angle. It is sectional drawing which shows the 2nd Embodiment of this invention. It is an expanded sectional view of the plunger unit shown in FIG. It is sectional drawing of the YY part of the plunger unit shown in FIG. It is sectional drawing which shows the conventional fixed type constant velocity universal joint. It is an expanded sectional view of the plunger unit shown in FIG. It is a principal part expanded sectional view of the plunger unit shown in FIG. (A) is a figure which shows a steering device. (B) is a lateral arrow view of (A). (C) is a perspective view showing a steering device arranged with the steering shaft bent.

Explanation of symbols

1, 41 Fixed type constant velocity universal joint (BJ)
2 Outer ring (outer joint member)
3 Inner peripheral surface (outer ring)
4 Track groove (outer ring)
5 Inner ring (inner joint member)
6 Outer peripheral surface (inner ring)
7 Track groove (inner ring)
8 Shaft 9 Inner member 10 Cage 13 Ball 17, 57 Plunger unit 18, 58 Compression coil spring (elastic member)
19, 59 Case 20, 60 Ball (Pressing member)
21, 61 Pressing part 22 Receiving member 23 Receiving part 24 Recessed part (shaft)
31, 71 ridge

Claims (4)

An outer member in which a plurality of curved track grooves are formed on a spherical inner peripheral surface, and a plurality of curved track grooves that are paired with the track grooves of the outer member are formed on a spherical outer peripheral surface. A plurality of balls interposed between the outer member, the track groove of the outer member and the track groove of the inner member, and the ball disposed between the outer member and the inner member. A plunger unit that includes a holding portion and has a pressing portion that causes an elastic pressing force to act in the axial direction, and is fitted into a recessed portion formed in the inner member, so that the pressing force from the pressing portion is applied to the cage. A fixed type constant velocity universal joint provided with a receiving part,
The plunger unit has a bottomed cylindrical case having an opening at one end, a pressing member having the pressing portion at the tip, and a pressing portion of the pressing member protruding from the opening of the case with an elastic force. An elastic member that biases in the direction is housed, the outer peripheral surface of the case, and a portion excluding the axial range in which the pressing member protrudes and retracts is press-fitted into the recessed portion of the inner member, A fixed type constant velocity universal joint provided with a ridge portion extending at least over the entire axial length of the press-fit portion .   The fixed type constant velocity universal joint according to claim 1, wherein the protrusions are provided at a plurality of locations in the circumferential direction.   The fixed type constant velocity universal joint according to claim 2, wherein the protrusions are provided at equal intervals along the circumferential direction.   The fixed type constant velocity universal joint according to claim 3, wherein the protrusions are provided at three locations in the circumferential direction at equal intervals.

Images