JP2011149551A - Tripod constant-velocity universal joint - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To dispense with turning working and exclusive equipment, facilitate achievement of sure locking with a simple means, simplify a working process and reduce the cost. <P>SOLUTION: A tripod constant-velocity universal joint includes: an outer joint member 10 having a cup shape with an opening 11 at one end and formed with, in the inner peripheral face, three track grooves 12 extending in the axial direction and, on the inner wall of each track groove 12, roller guide faces 14 facing each other; a tripod member 20 having three radially-projecting leg shafts 22; and roller units 30 rotatably supported on the leg shafts 22 of the tripod member 20, inserted rollably in the track grooves 12 of the outer joint member 10 and guided along the roller guide faces 14. Inner components including the roller units 30 and the tripod member 20 are contained in the outer joint member 10 slidably in the axial direction. Projections 15, onto which the roller units 30 of the inner components are latched, are provided through simultaneous molding by forging of the outer joint member 10 on the roller guide faces 14, which are on the inner peripheral surface of the opening 11 of the outer joint member 10 and on the opposite sides of each track groove 12. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention is used in power transmission systems of automobiles, airplanes, ships, and various industrial machines, and is incorporated into a drive shaft, a propeller shaft, etc. used in, for example, a 4WD vehicle, an FR vehicle, etc. The present invention relates to a tripod type constant velocity universal joint which is a kind of a sliding type constant velocity universal joint that allows axial displacement and angular displacement between them.

  For example, there are two types of constant velocity universal joints, such as fixed constant velocity universal joints and sliding constant velocity universal joints, that are built into drive shafts and propeller shafts that transmit rotational force from automobile engines to wheels at constant speed. is there. 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 constant velocity universal joint on the drive wheel side (outboard side), and a structure in which both constant velocity universal joints are connected by a shaft.

  One of the sliding type constant velocity universal joints assembled to the drive shaft is a tripod type constant velocity universal joint. This tripod type constant velocity universal joint has a cup shape having an opening at one end, three track grooves extending in the axial direction are formed on the inner peripheral surface, and roller guides facing each other on the inner wall of each track groove An outer joint member formed with a surface, a tripod member having three leg shafts projecting in the radial direction, and rotatably supported by the leg shaft of the tripod member and rolling in a track groove of the outer joint member And a roller guided along the roller guide surface to form a main portion, and an internal component including the roller and the tripod member is accommodated in the outer joint member so as to be slidable in the axial direction.

  When assembling this type of tripod type constant velocity universal joint to an automobile, the tripod type constant velocity universal joint is assembled on the engine side (inboard side), and then the fixed type constant velocity universal joint is installed on the drive wheel side (outboard side). ) Is generally assembled. On the drive wheel side, the hub bearing is assembled to the fixed type constant velocity universal joint, and is assembled to the suspension system of the vehicle body by the knuckle, but when the hub bearing is assembled to the fixed type constant velocity universal joint, the hub bearing and the knuckle are attached to the vehicle body. Since the tripod type constant velocity universal joint is not assembled to the suspension device, a total load (for example, 0.3 kN or more) of the fixed type constant velocity universal joint, the hub bearing, and the knuckle may be applied. When such a load is applied to the tripod type constant velocity universal joint, a slide over may occur in which the internal part jumps out of the opening of the outer joint member. Therefore, conventionally, in order to prevent this slide-over, the following retaining mechanism is employed.

  As one of the retaining mechanisms, there is a structure in which an annular groove is provided on the inner peripheral surface of the opening of the outer joint member, and a circlip is fitted into the annular groove (see, for example, Patent Document 1). With such a structure, when the internal component is displaced in the axial direction, the roller interferes with the circlip so that the axial displacement amount of the roller is regulated.

  In addition, as another retaining mechanism, a pair of left and right spherical recesses that open to the outer sides of the roller guide surface of the outer joint member and a pair of left and right spheres that extend to the closed side are formed on the upper and lower sides of the opening end of the roller guide surface. There is a structure in which convex portions are arranged (see, for example, Patent Document 2). With such a structure, when the internal component is displaced in the axial direction, the roller interferes with the spherical convex portion, thereby restricting the axial displacement amount of the roller.

  Furthermore, as another retaining mechanism, there is a structure in which a protruding portion is formed on the inner peripheral surface of the opening of the outer joint member by crushing the inner edge of the opening end face of the outer joint member by caulking (for example, a patent) Reference 3). With such a structure, when the internal component is displaced in the axial direction, the roller interferes with the raised portion so that the axial displacement amount of the roller is regulated.

Japanese Utility Model Publication No. 10-194 Japanese Utility Model Publication No. 58-30027 Japanese Patent Application Laid-Open No. 11-336782

  By the way, in the conventional constant velocity universal joint disclosed in the above-mentioned Patent Document 1, a circular clip is formed on the inner peripheral surface of the opening of the outer joint member in order to assemble the circlip for restricting the axial displacement of the roller to the outer joint member. Since the inner peripheral surface of the opening of the outer joint member must be turned and a circlip is also required, the cost of the product is increased by turning and increasing the number of parts. .

  Further, in the conventional constant velocity universal joint disclosed in Patent Document 2, when the constant velocity universal joint is assembled to an automobile, the roller freely moves when no rotational torque is input, so that the roller is a roller guide surface of the outer joint member. There is a possibility that the roller will come out from the spherical concave portion, and it will be difficult to reliably exert the retaining function.

  Furthermore, in the conventional constant velocity universal joint disclosed in Patent Document 3, the inner edge portion of the opening end face of the outer joint member is crushed by caulking, so that the outer joint member is accurately positioned with respect to the caulking jig. The positioning of the outer joint member is very difficult and requires special equipment for positioning the outer joint member. Moreover, since it forms by crushing a protruding part by caulking, the size dimension of the protruding part tends to vary.

  Therefore, the present invention has been proposed in view of the above-mentioned problems, and the object of the present invention is to eliminate the need for turning and dedicated equipment, and to easily realize reliable retaining by simple means and the machining process. An object of the present invention is to provide a tripod type constant velocity universal joint that can be simplified and cost can be reduced.

  As technical means for achieving the above-mentioned object, the present invention has a cup shape having an opening at one end, and three track grooves extending in the axial direction are formed on the inner peripheral surface. An outer joint member having roller guide surfaces facing each other on the inner wall, a tripod member having three leg shafts projecting in the radial direction, and an outer joint supported rotatably on the leg shaft of the tripod member A tripod in which an inner part including the roller and the tripod member is accommodated in the outer joint member so as to be axially slidable. The constant velocity universal joint is formed by forging the outer joint member on the inner peripheral surface of the opening of the outer joint member and on the roller guide surface of at least one side of the track groove by the inner part roller. Characterized by providing at the time of molding.

  The above-mentioned “at least one side” means that a convex portion is provided on one side of a pair of roller guide surfaces facing each other on the inner wall of the track groove, or a convex portion is provided on both sides of the pair of roller guide surfaces. Means to include both.

  In the tripod type constant velocity universal joint according to the present invention, since the inner peripheral surface of the opening of the outer joint member is provided with a convex portion for locking the roller of the internal component on the roller guide surface on at least one side of the track groove, By restricting the amount of axial displacement of the internal component by the roller interfering with the convex portion during axial displacement, it is possible to prevent the internal component from sliding out from the opening of the outer joint member. In particular, when this tripod type constant velocity universal joint is assembled to a car as a drive shaft, even if the total load of the fixed type constant velocity universal joint, hub bearing and knuckle is applied to the tripod type constant velocity universal joint, the internal parts are the outer joint members. This is effective in that it is possible to surely prevent a slide-over jumping out from the opening of the.

  On the other hand, the convex part is formed by forging the outer joint member at the same time, so that it can be used for turning for forming an annular groove like the conventional one, another part such as a circlip, and a caulking jig. On the other hand, a dedicated facility for positioning the outer joint member can be dispensed with, and variations in the size of the convex portion are unlikely to occur, and the convex portion can be formed with high accuracy. In addition, the retaining function can be surely exhibited by a simple means of simultaneous forming by forging of the outer joint member, and the machining process can be simplified and the cost can be reduced.

  In the present invention, the tightening margin between the convex portion and the roller is preferably 0.2 to 0.8 mm. In this way, when the internal part is displaced in the axial direction, the roller can be reliably locked to the convex portion, and the mold can be easily pulled out during the forging of the outer joint member, so that the convex portion is simultaneously formed. This can be easily realized, and the inner part can be easily press-fitted into the outer joint member when the inner part is assembled to the outer joint member.

  Note that if the tightening margin between the convex portion and the roller is smaller than 0.2 mm, the resistance becomes too small, so that the mold can be easily pulled out during forging of the outer joint member, and the convex portion can be simultaneously formed. It can be easily realized, and the inner part can be easily press-fitted into the outer joint member when the inner part is assembled to the outer joint member. On the other hand, when the internal part is displaced in the axial direction, the roller is securely locked to the convex part. It is unsuitable because it is difficult to do.

  On the contrary, if the allowance between the convex part and the roller is larger than 0.8 mm, the resistance becomes too large, so that the roller can be reliably locked to the convex part when the internal component is displaced in the axial direction. When the outer joint member is forged, it is difficult to pull out the mold, and it becomes difficult to form the convex portion at the same time, and the inner part can be press-fitted into the outer joint member when the inner part is assembled to the outer joint member. It is unsuitable because it becomes difficult.

  It is desirable that the convex portion in the present invention is provided with a tapered surface that is inclined with respect to the joint axis and reaches the roller guide surface on the side opposite to the opening of the outer joint member. In this way, the resistance is reduced by the tapered surface, which is effective in that it is easier to pull out the mold during forging of the outer joint member and it is possible to more easily realize the simultaneous forming of the convex portion. It is.

  In addition, the taper surface of the convex portion in the present invention desirably has a taper angle of 45 ° or less. In this way, when the internal part is displaced in the axial direction, the interference between the roller and the convex portion is ensured, and the taper angle is small, so that it becomes even easier to pull out the mold when forging the outer joint member. Thus, it is effective in that the simultaneous forming of the convex portions can be realized more easily. If the taper angle is larger than 45 °, it is not suitable because it is difficult to draw the mold during forging of the outer joint member and it becomes difficult to simultaneously form the convex portions.

  The convex portion in the present invention is desirably provided at least at the roller contact position of the roller guide surface. In this way, for example, even when the tightening margin between the convex portion and the roller is reduced, it is effective in that the roller can be reliably locked to the convex portion when the internal component is displaced in the axial direction. is there. Note that “at least the roller contact position” means that it is possible to provide a convex portion at a portion other than the roller contact position. Even if the convex part is provided in a part other than the roller contact position on the roller guide surface, for example, if the tightening margin between the convex part and the roller is increased, the roller is locked to the convex part when the internal component is displaced in the axial direction. Is possible.

  The convex portion in the present invention is desirably provided in a region having a width of 1 mm from the roller contact position of the roller guide surface to both sides in the radial direction. In order to ensure good operability of the constant velocity universal joint, the movement amount of the roller in the radial direction may be set to 1 mm or less. Therefore, if a convex portion is provided in a region having a width of 1 mm from the roller contact position of the roller guide surface to both sides in the radial direction, even if the roller moves in the radial direction within that region, the roller is securely locked to the convex portion. It is effective in that it can be made to.

  In the present invention, the roller contact surface with the roller guide surface may be either angular contact or circular contact. In the case of angular contact, convex portions are formed at roller contact positions located at two locations in the radial direction of the roller guide surface. On the other hand, in the case of circular contact, a convex portion is formed at the roller contact position (outer joint member PCD) located at one place in the radial direction of the roller guide surface. Here, the “outer joint member PCD” means the PCD (pitch circle diameter) of the roller in contact with the roller guide surface of the track groove of the outer joint member.

  The roller in the present invention is an outer roller arranged on the outer peripheral side of the inner roller fitted on the leg shaft, the inner peripheral surface of the inner roller has a convex arc shape, and the leg shaft is orthogonal to the axis of the joint in the longitudinal section. A structure in which the cross section is in contact with the inner peripheral surface of the inner roller in the direction perpendicular to the joint axis in the cross section, and a gap is formed between the inner peripheral surface of the inner roller in the axial direction of the joint. It is desirable to have it.

  That is, it is effective to apply the present invention to a double roller type tripod type constant velocity universal joint. The present invention can also be applied to other than the double roller type, for example, a single roller type tripod type constant velocity universal joint.

  According to the present invention, at least one roller guide surface of the track groove on the inner peripheral surface of the opening of the outer joint member is provided with a convex portion that is engaged with the roller of the internal component. Since the roller interferes with the convex portion to restrict the amount of axial displacement of the internal component, it is possible to prevent the internal component from sliding out from the opening of the outer joint member. In addition, the convex part is formed by forging the outer joint member at the same time, so that it can be used for turning for forming an annular concave groove as in the past, another part such as a circlip, and a caulking jig. On the other hand, a dedicated facility for positioning the outer joint member can be dispensed with, and variations in the size of the convex portion are unlikely to occur, and the convex portion can be formed with high accuracy. In addition, the retaining function can be surely exhibited by a simple means of simultaneous forming by forging of the outer joint member, and the machining process can be simplified and the cost can be reduced.

  In this way, by providing the convex part that the roller of the internal part is locked to at least one roller guide surface of the track groove on the inner peripheral surface of the opening of the outer joint member by simultaneous forming by forging of the outer joint member, it is inexpensive. A highly reliable tripod type constant velocity universal joint can be provided.

In embodiment of the tripod type constant velocity universal joint which concerns on this invention, it is a longitudinal cross-sectional view with respect to the axis line of a joint. It is an embodiment of the tripod type constant velocity universal joint according to the present invention, and is a view taken in the direction of arrow A in FIG. It is sectional drawing which shows the leg axis | shaft and roller unit of FIG. 1 and FIG. It is a partial expanded sectional view which follows the BB line of FIG. It is a principal part expanded sectional view which shows the case where an outer roller makes an angular contact with an outer joint member. It is a principal part enlarged view which shows a convex part in case an outer roller makes an angular contact with an outer joint member. It is a principal part expanded sectional view which shows the case where an outer roller makes circular contact with an outer joint member. It is a principal part enlarged view which shows a convex part in case an outer roller makes circular contact with an outer joint member.

  The embodiment of the tripod type constant velocity universal joint according to the present invention will be described in detail below. In the following embodiments, a double roller type tripod type constant velocity universal joint capable of reducing vibration during operation will be exemplified. The present invention can be applied to other tripod type constant velocity universal joints such as a single roller type in addition to the double roller type.

  1 and 2 show the basic structure of a double roller type tripod type constant velocity universal joint, FIG. 1 shows a longitudinal section with respect to the axis of the joint, and FIG. 2 shows an arrow view seen from the direction A in FIG. (However, only one roller unit 30 is shown in cross section). In the tripod type constant velocity universal joint of this embodiment, the outer joint member 10, the tripod member 20, and the roller unit 30 constitute main parts.

  The outer joint member 10 has a cup shape having an opening 11 at one end, and a rotation shaft (for example, a drive shaft) (not shown) is integrally formed at the center of the bottom portion. Three linear track grooves 12 extending in the axial direction are formed on the inner peripheral surface of the outer joint member 10 at equal intervals in the circumferential direction. Each track groove 12 has a pair of roller guide surfaces 14 opposed to each other on both inner walls thereof. The roller guide surface 14 has an arc-shaped cross section and extends linearly in the axial direction of the outer joint member 10. On the outer peripheral surface of the outer joint member 10, a portion corresponding to the space between the track grooves 12 is thinned to reduce the weight, and a recess 13 is formed in the axial direction. Internal parts including the tripod member 20 and the roller unit 30 are accommodated in the outer joint member 10.

  The roller unit 30 includes an outer roller 32, an inner roller 34 that is disposed inside the outer roller 32 and is externally fitted to the leg shaft 22, and a needle roller 36 that is interposed between the outer roller 32 and the inner roller 34. It is comprised and is accommodated in the track groove 12 of the outer joint member 10. The inner peripheral surface of the inner roller 34 has a convex arc shape. A plurality of needle rollers 36 are disposed between the inner roller 34 and the outer roller 32 in a so-called single row full roller state without a cage. The inner roller 34 and the needle roller 36 are fitted with ring-shaped washers 31 and 33 in an annular groove formed on the inner peripheral surface of the outer roller 32, and are prevented from coming off from the outer roller 32 by the washers 31 and 33. .

  The tripod member 20 is formed by integrally forming three leg shafts 22 radially at equal intervals in the circumferential direction (120 ° intervals) on the outer peripheral surface of a cylindrical boss portion 21. The front end of the leg shaft 22 extends in the radial direction to the vicinity of the bottom surface of the track groove 12. The shaft end of the rotating shaft 40 (for example, a driven shaft) is connected to the shaft hole of the boss 21 by spline fitting, and is prevented from coming off from the tripod member 20 by an annular snap ring 42. The leg shaft 22 of the tripod member 20 has a straight shape perpendicular to the axis of the joint in the longitudinal section with respect to the axis, and as shown in FIG. 3, the direction orthogonal to the axis of the joint in the transverse section with respect to the axis of the leg shaft 22. Thus, an elliptical shape that contacts the inner roller 34 is formed, and a gap n is formed between the inner roller 34 and the inner roller 34 in the axial direction of the joint. The roller unit 30 is rotatably supported on the leg shaft 22 having such a shape.

  In this constant velocity universal joint, the leg shaft 22 of the tripod member 20 and the roller guide surface 14 of the outer joint member 10 are engaged with each other in the biaxial rotation direction via the roller unit 30, so that the drive side is moved to the driven side. Rotational torque is transmitted at a constant speed. Further, when the roller unit 30 rolls on the roller guide surface 14 while rotating with respect to the leg shaft 22, relative axial displacement and angular displacement between the outer joint member 10 and the tripod member 20 are absorbed. Is done.

  At this time, a gap n is formed between the leg shaft 22 and the inner roller 34 in the axial direction of the joint, and the leg shaft 22 is tiltable with respect to the roller unit 30 that rolls on the roller guide surface 14. Therefore, even if the joint takes an operating angle, the roller unit 30 does not tilt with respect to the roller guide surface 14. In this way, the roller unit 30 and the roller guide surface 14 are prevented from being obliquely crossed with the inclination of the leg shaft 22, thereby reducing induced thrust and slide resistance.

  In the tripod type constant velocity universal joint according to this embodiment, the following retaining mechanism is employed in order to prevent a slide-over in which internal parts including the tripod member 20 and the roller unit 30 jump out of the opening 11 of the outer joint member 10. To do.

  As shown in FIGS. 1 and 2, the tripod type constant velocity universal joint has a pair of rollers facing each other on both inner walls of the track groove 12 on the inner peripheral surface of the opening 11 of the outer joint member 10. The guide surface 14 is provided with a structure in which a convex portion 15 to which an outer roller 32 as an internal part is locked is provided. In this embodiment, the case where the convex portions 15 are provided on the roller guide surfaces 14 of all three track grooves 12 is illustrated, but the convex portions 15 are projected on at least one of the track grooves 12. The portion 15 may be provided, and the convex portion 15 may be provided only on the roller guide surface 14 located on one side of the pair of roller guide surfaces 14 located on both sides of the track groove 12.

  Here, the outer joint member 10 is manufactured, for example, by forming a material made of medium carbon steel into a general shape by forging, and then performing turning, high-frequency heat treatment, grinding, or the like. The convex portion 15 as the internal component retaining mechanism is simultaneously formed by forging the outer joint member 10 described above. Moreover, the above-mentioned convex part 15 does not need to perform the hardening process by heat processing.

  In this way, the convex portion 15 is simultaneously formed by forging the outer joint member 10, so that it can be turned into another part such as a conventional circular concave groove, a circlip, or a caulking jig. On the other hand, a dedicated facility for positioning the outer joint member can be eliminated, the size of the convex portion 15 hardly varies, and the convex portion 15 can be formed with high accuracy. In addition, the retaining function can be surely exhibited by a simple means of simultaneous forming by forging of the outer joint member 10, and the machining process can be simplified and the cost can be reduced.

  In this tripod type constant velocity universal joint, the convex part 15 which the outer roller 32 of an internal component latches was provided in the roller guide surface 14 of the both sides of the track groove 12 in the inner peripheral surface of the opening part 11 of the outer joint member 10. From the above, when the internal component is displaced in the axial direction, the outer roller 32 interferes with the convex portion 15 to restrict the amount of axial displacement of the internal component, thereby causing the internal component to slide out from the opening 11 of the outer joint member 10. It can be prevented in advance. For example, when this tripod type constant velocity universal joint is assembled to a car as a drive shaft, the inner part is an outer joint member even if the total load of the fixed type constant velocity universal joint, hub bearing and knuckle is applied to the tripod type constant velocity universal joint. The slide over which jumps out from the 10 opening parts 11 can be prevented reliably.

  As described above, when the convex portion 15 is simultaneously formed by forging the outer joint member 10, it is necessary to provide a concave portion corresponding to the convex portion 15 in the mold used for the forging. When the outer joint member 10 is forged, a die is press-fitted into the outer joint member 10 to form its internal shape (track groove 12 and roller guide surface 14). Pulled out. When the mold is pulled out, the concave portion of the mold becomes a resistance against the outer joint member 10. Further, when the inner part is assembled into the outer joint member 10 after the outer joint member 10 is forged, the outer roller 32 of the roller unit 30 is connected to the outer joint because the convex portion 15 of the outer joint member 10 becomes a resistance against the inner part. It press-fits into the track groove 12 of the member 10.

  Therefore, in a state where the internal part is incorporated in the outer joint member 10, the tightening allowance between the convex portion 15 and the outer roller 32 is set to 0.2 to 0.8 mm. When the tightening margin is 0.2 mm, the internal component pull-out force when the operating angle of the constant velocity universal joint is 0 ° is 1.0 kN. When the tightening margin is 0.8 mm, the operating angle of the constant velocity universal joint is The pull-out force of the internal parts at 0 ° is 6.5 kN.

  In this way, by setting the tightening margin between the convex portion 15 and the outer roller 32 to 0.2 to 0.8 mm, the outer roller 32 can be reliably locked to the convex portion 15 when the internal component is displaced in the axial direction. When the outer joint member 10 is forged, since the resistance due to the concave portion of the mold is small, it is easy to pull out the mold, and it is possible to easily form the convex portion 15 at the same time, and to suppress the life reduction of the mold. In addition, when the inner part is assembled to the outer joint member 10, since the resistance by the convex portion 15 of the outer joint member 10 is small, the inner part can be easily press-fitted into the outer joint member 10.

  If the tightening margin between the convex portion 15 and the outer roller 32 is smaller than 0.2 mm, the resistance due to the concave portion of the mold is small at the time of forging the outer joint member 10, so that the mold can be easily pulled out. It is possible to easily form the portion 15 at the same time, and when the inner part is assembled to the outer joint member 10, the resistance of the convex part 15 of the outer joint member 10 is small, so that the inner part is attached to the outer joint member 10. Although it can be easily press-fitted, it is not suitable because it is difficult to securely lock the outer roller 32 to the convex portion 15 when the internal component is displaced in the axial direction.

  On the contrary, when the tightening allowance between the convex portion 15 and the outer roller 32 is larger than 0.8 mm, the outer roller 32 can be reliably locked to the convex portion 15 when the internal component is displaced in the axial direction. At the time of forging 10, since the resistance due to the concave portion of the mold is large, it is difficult to pull out the mold and it becomes difficult to form the convex portion 15 at the same time. Also, when assembling the inner part to the outer joint member 10 Since the resistance due to the convex portion 15 of the outer joint member 10 is large, it is difficult to press-fit the internal component into the outer joint member 10.

  Here, if the tightening margin of the convex portion 15 and the outer roller 32 is the same, the removal force of the internal parts is also equivalent. That is, for one track groove 12, the total height of the convex portions 15 is the same regardless of whether the convex portions 15 are provided on the roller guide surface 14 on one side or the convex portions 15 are provided on the roller guide surfaces 14 on both sides. If there is, the removal force of the internal parts is equivalent. Therefore, it is preferable to provide the mold with the same removal force of the internal parts by providing the convex portions 15 at half the height on the roller guide surfaces 14 on both sides, rather than providing the convex portions 15 on the roller guide surface 14 on one side. It is more effective to provide the convex portions 15 on the roller guide surfaces 14 on both sides in that it can be easily pulled out and the life of the mold can be improved.

  FIG. 4 is an enlarged partial cross-sectional view taken along the line BB in FIG. 1 and shows the convex portion 15 provided on the roller guide surface 14. As shown in the figure, the convex portion 15 is provided with a tapered surface 16 that is inclined with respect to the joint axis and reaches the roller guide surface 14 on the side opposite to the opening of the outer joint member 10. As described above, since the convex portion 15 has the tapered surface 16 on the side opposite to the opening of the outer joint member 10, a reverse tapered surface is formed corresponding to the concave portion of the mold. Since the resistance due to the concave portion of the mold is further reduced at the time of forging, it is easier to pull out the mold and simultaneously form the convex portion 15 than when the tapered surface 16 is not provided. At the same time, it is possible to suppress a reduction in the service life of the mold.

  The taper surface 16 of the convex portion 15 has a taper angle θ of 45 ° or less. In this way, by restricting the taper angle θ to 45 ° or less, when the internal component is displaced in the axial direction, the interference between the outer roller 32 and the convex portion 15 is ensured and the taper angle θ is small. When the member 10 is forged, the resistance due to the concave portion of the mold is further reduced, the mold can be easily pulled out, and the convex portion 15 can be easily formed at the same time, and the decrease in the life of the mold can also be suppressed. . If the taper angle θ is larger than 45 °, the resistance due to the concave portion of the mold is increased during the forging of the outer joint member 10, so that it is difficult to pull out the mold, and the convex portion 15 is simultaneously formed. And the life of the mold is reduced.

  In this embodiment, as shown in FIG. 5, the case where the outer roller 32 is in angular contact with the roller guide surface 14 is illustrated. In the case of angular contact, the outer peripheral surface of the outer roller 32 contacts at two locations in the radial direction of the roller guide surface 14 (roller contact position P). FIG. 5 shows a cross section of the roller guide surface 14 at a portion where the convex portion 15 (see FIG. 6) is not formed.

  In the case of this angular contact, the convex portion 15 is provided at the roller contact position P of the roller guide surface 14 as shown in FIG. When the convex portion 15 is provided at the roller contact position P of the roller guide surface 14 in this way, for example, the tightening margin between the convex portion 15 and the outer roller 32 is reduced within the above-described range of 0.2 to 0.8 mm. Even so, the outer roller 32 can be reliably locked to the convex portion 15 when the internal component is displaced in the axial direction.

  In addition, it is also possible to provide the convex part 15 in parts other than the roller contact position P. Even if the convex portion 15 is provided in a portion other than the roller contact position P of the roller guide surface 14, for example, if the tightening margin between the convex portion 15 and the outer roller 32 is increased within the range of 0.2 to 0.8 mm described above. The outer roller 32 can be locked to the convex portion 15 when the internal component is displaced in the axial direction.

  In this embodiment, as shown in FIG. 6, the convex part 15 is provided in the area | region R which has 1 mm width W from the roller contact position P of the roller guide surface 14 to a radial direction both sides. Usually, in order to ensure good operability of the tripod type constant velocity universal joint, the movement amount of the outer roller 32 in the radial direction may be set to 1 mm or less. Therefore, even if the outer roller 32 moves in the radial direction in the region R by providing the convex portion 15 in the region R having a width W of 1 mm on both sides in the radial direction from the roller contact position P of the roller guide surface 14 as described above. The outer roller 32 can be reliably locked to the convex portion 15.

  In the above embodiment, the case where the outer roller 32 is in angular contact with the roller guide surface 14 has been described. However, the present invention can also be applied to the case where the outer roller 32 is in circular contact with the roller guide surface 14 ′.

  FIG. 7 illustrates a case where the outer roller 32 is in circular contact with the roller guide surface 14 ′. In the case of circular contact, the outer peripheral surface of the outer roller 32 comes into contact with one place (roller contact position P ′) in the radial direction of the roller guide surface 14 ′. The roller contact position P ′ in the circular contact is the outer joint member PCD, that is, the PCD (pitch circle diameter) of the outer roller 32 in a state of contacting the roller guide surface 14 ′ of the track groove 12 of the outer joint member 10. ing. FIG. 7 shows a cross section of the roller guide surface 14 ′ at a portion where the convex portion 15 ′ (see FIG. 8) is not formed.

  In the case of this circular contact, as in the case of the angular contact, as shown in FIG. 8, the convex portion 15 'is provided at the roller contact position P' of the roller guide surface 14 '. In this case as well, it is possible to provide the convex portion 15 ′ at a portion other than the roller contact position P ′. In this embodiment, a convex portion 15 ′ is provided in a region R ′ having a 1 mm width W ′ on both sides in the radial direction from the roller contact position P ′ of the roller guide surface 14 ′. Note that the embodiment in the case of this circular contact also has the same effect as the embodiment in the case of the above-described angular contact, and therefore redundant description 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.

DESCRIPTION OF SYMBOLS 10 Outer joint member 11 Opening part 12 Track groove 14 Roller guide surface 15 Convex part 16 Tapered surface 20 Tripod member 22 Leg shaft 32 Roller (outer roller)
34 Inner roller θ Taper angle P Roller contact position

Claims (9)

An outer joint member having a cup shape having an opening at one end, three track grooves extending in the axial direction on the inner peripheral surface, and roller guide surfaces facing each other on the inner wall of each track groove; A tripod member having three leg shafts projecting in the radial direction; and a roller guide surface rotatably supported on the leg shaft of the tripod member and rotatably inserted into a track groove of the outer joint member. A tripod type constant velocity universal joint in which an inner part including the roller and the tripod member is accommodated in the outer joint member so as to be axially slidable,
The outer joint member has an inner peripheral surface of the opening, and at least one roller guide surface of the track groove is provided with a convex portion to be locked by the roller of the inner part by simultaneous forming by forging of the outer joint member. Tripod type constant velocity universal joint.   The tripod type constant velocity universal joint according to claim 1, wherein a tightening margin between the convex portion and the roller is 0.2 to 0.8 mm.   The tripod type constant velocity according to claim 1, wherein the convex portion is provided with a tapered surface that is inclined with respect to an axis of the joint and reaches the roller guide surface on a side opposite to the opening of the outer joint member. Universal joint.   The tripod type constant velocity universal joint according to claim 3, wherein the taper surface of the convex portion has a taper angle of 45 ° or less.   The tripod type constant velocity universal joint according to any one of claims 1 to 4, wherein the convex portion is provided at least at a roller contact position of the roller guide surface.   The tripod type constant velocity universal joint according to any one of claims 1 to 5, wherein the convex portion is provided in a region having a width of 1 mm from the roller contact position of the roller guide surface to both sides in the radial direction.   The tripod type constant velocity universal joint according to any one of claims 1 to 6, wherein the roller contacts the roller guide surface by an angular contact.   The tripod constant velocity universal joint according to any one of claims 1 to 6, wherein the roller contacts the roller guide surface by circular contact.   The roller is an outer roller disposed on an outer peripheral side of an inner roller that is externally fitted to the leg shaft, and an inner peripheral surface of the inner roller has a convex arc shape, and the leg shaft is orthogonal to an axis of a joint in a longitudinal section. Forming a straight shape, in contact with the inner peripheral surface of the inner roller in a direction perpendicular to the axis of the joint in the cross section, and a gap is formed between the inner peripheral surface of the inner roller in the axial direction of the joint The tripod type constant velocity universal joint as described in any one of Claims 1-8.

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