JP5901950B2 - Spline fitting structure - Google Patents

Description

  The present invention relates to a spline fitting structure of an inner joint member and a shaft of a constant velocity universal joint used in a power transmission system such as an automobile.

  As is well known, for example, in a power transmission system of an automobile or various industrial machines, a constant velocity universal joint is widely used in order to transmit torque while allowing angular displacement between two axes of a driving side and a driven side.

  The constant velocity universal joint includes an outer joint member, an inner joint member positioned inward of the outer joint member, and a torque transmission member that transmits torque between the outer joint member and the inner joint member. To do.

  One of the drive side and driven side two shafts is connected to the outer joint member of the constant velocity universal joint, and the other of the two shafts is connected to the inner joint member.

  The shaft is connected to the inner joint member by fitting a male spline formed on the outer peripheral surface of the tip of the shaft to a female spline formed on the inner peripheral surface of the shaft hole of the inner joint member. In order to facilitate alignment during the connecting operation, chamfering is provided at the insertion start end of the male spline of the shaft and the insertion start end of the female spline of the inner joint member (see, for example, Patent Document 1). ).

  These chamfers facilitate the alignment of the female spline and the male spline, and the spline tooth surfaces can be easily fitted to each other, but the effect is not sufficient. In actual connection work, the male spline and the female spline Often, it took time to align the teeth.

  For such a situation, as a method for facilitating the fitting of the male spline and the female spline, for example, in Patent Document 2, at the tip of the shaft member, further from the chamfered portion of the male spline to the insertion start side along the axial direction. A method of providing a protruding shaft portion that protrudes is disclosed. In this method, when the male spline is fitted into the female spline, the protruding shaft portion is inserted into the female spline in advance, whereby the male spline is guided to the protruding shaft portion. Thereby, the fitting operation | work to the female spline of a male spline becomes easy.

JP 2009-185878 A JP 2010-281431 A

  However, when the method of Patent Document 2 is applied to a shaft that fits into the inner joint member of a constant velocity universal joint, the protruding shaft portion protrudes from the insertion start end of the male spline, so After the fitting, the tip of the shaft protrudes from the inner joint member by the protruding shaft portion. The above-described male spline guide effect of the protruding shaft portion increases as the axial length of the protruding shaft portion increases. Therefore, when the axial length of the protruding shaft portion is increased in order to increase the guiding effect, it is necessary to make a wide space around the tip of the shaft protruding from the inner joint member. The bottom must be deepened. For this reason, the volume and weight of the outer joint member and thus the entire constant velocity universal joint are increased. This is contrary to the market demand for compact and lightweight constant velocity universal joints.

  The same problem is assumed not only in the operation of inserting the male spline of the shaft into the female spline of the inner joint member of the constant velocity universal joint, but also in the operation of generally inserting the male spline of the shaft member into the female spline of the inserted member. The

  In view of the above circumstances, it is a technical object of the present invention to facilitate the fitting operation of the male spline to the female spline while suppressing the length of the tip of the shaft member protruding from the inserted member after the fitting. .

The spline fitting structure according to the present invention for solving the above-described problems is a fitting member in which a shaft member having a male spline provided on the outer peripheral surface and a female spline capable of fitting the male spline provided on the inner peripheral surface are provided. and a member in a spline fitting structure in which a second chamfer the insertion start end of the female spline of the object to be insert member provided with a first chamfered portion into the fitting start end of the male spline of the shaft member, wherein The fitted member is an inner joint member of a constant velocity universal joint, the shaft member is a shaft fitted into the inner joint member, and the chamfer angle of the first chamfered portion is 10 ° from the chamfer angle of the second chamfered portion. The chamfering angle of the first chamfered portion is set to 15 to 25 ° and the chamfered angle of the second chamfered portion is set to 25 to 60 °.

  Here, the spline includes not only a rectangular shape but also a triangular shape or a trapezoidal shape in the cross-sectional shape of the convex portion of the male spline and the concave portion of the female spline (hereinafter the same). The chamfering angle of the chamfered portion is an angle formed by a straight line portion in the axial section of the chamfered portion with respect to the axial direction (hereinafter the same).

  In this configuration, the chamfer angle of the first chamfered portion is set to be 10 ° or more smaller than the chamfer angle of the second chamfered portion, the chamfer angle of the first chamfered portion is set to 15 to 25 °, and the chamfer angle of the second chamfered portion is set. Is set to 25 to 60 °. Thus, even when the center axis of the male spline is slightly inclined with respect to the center axis of the female spline at the start of insertion, the inner peripheral side corner of the second chamfered portion of the female spline abuts (or opposes) the male spline. ) Therefore, when the member to be inserted and the shaft member are relatively rotated in order to perform phase matching, the tooth surfaces of the female spline of the member to be inserted and the male spline of the shaft member are likely to mesh with each other. Therefore, the operation | work which inserts the male spline of a shaft member into the female spline of a to-be-inserted member can be made easy.

  In the conventional spline fitting structure, the chamfer angle is not defined as in the present invention, but generally, a chamfer corresponding to the first chamfer or the second chamfer is provided. Therefore, the spline fitting structure of the present invention can be implemented by changing the chamfering angle of the chamfered portion in the conventional spline fitting structure. For this reason, it is possible to make the length of the tip of the shaft member protruding from the member to be fitted after insertion almost the same as the conventional length. Even if the length of the tip of the shaft member is increased, the length of the shaft member is increased. A large amount can be suppressed.

  The said structure WHEREIN: It is preferable to make the inner peripheral side corner | angular part in a said 2nd chamfer part, in other words, the inner peripheral side corner | angular part of a female spline into a round shape. With this configuration, when the center axis of the male spline is slightly inclined with respect to the center axis of the female spline at the start of insertion, this is compared to the case where the inner peripheral side corner of the female spline is angular. The peripheral portion of the inner peripheral side corner portion can easily abut (or face) the male spline. Therefore, when the inserted member and the shaft member are rotated relative to each other for phase matching, the tooth surfaces of the female spline and the male spline are more easily engaged. For this reason, the operation | work which inserts the male spline of a shaft member into the female spline of a to-be-inserted member becomes still easier.

If the constant velocity universal joint having a spline fitting structure of any of the above construction, operation and effects described above can be Oite enjoyed constant velocity universal joint hands.

  In this configuration, the axial displacement of the inner joint member relative to the shaft may be restricted by the shoulder portion of the shaft and a retaining ring fitted on the shaft. The constant velocity universal joint may be a fixed type constant velocity universal joint, and the constant velocity universal joint may be a sliding type constant velocity universal joint. Further, in these configurations, the constant velocity universal joint may be a drive shaft constant velocity universal joint, and the constant velocity universal joint may be a propeller shaft constant velocity universal joint.

  According to the present invention as described above, it is possible to facilitate the fitting operation of the male spline into the female spline while suppressing the length of the tip of the shaft member protruding from the fitted member after the fitting. Thereby, since the work time of insertion work can be shortened, productivity can be improved. Furthermore, since assembly work can be performed without any trouble even in assembly with a robot in an unmanned facility, the number of manual work steps can be reduced.

It is sectional drawing which shows the state with which the constant velocity universal joint which concerns on embodiment of this invention, and the shaft were connected. It is sectional drawing which shows the state with which the inner joint member and shaft of the constant velocity universal joint of FIG. 1 are not connected. It is sectional drawing which shows the state with which the constant velocity universal joint and shaft which concern on other embodiment of this invention were connected. FIG. 4 is a cross-sectional view showing a state where an inner joint member and a shaft of the constant velocity universal joint of FIG. 3 are not connected. It is sectional drawing which shows the state with which the constant velocity universal joint and shaft which concern on another embodiment of this invention were connected. FIG. 6 is a cross-sectional view showing a state where the inner joint member of the constant velocity universal joint of FIG. 5 is not connected to the shaft. It is sectional drawing which shows the state at the time of the fitting start of the shaft to the inner side coupling member of a constant velocity universal joint. ( A ) is an enlarged view of part A of FIG. 7, and (B) is an enlarged view of part B of FIG. It is sectional drawing which shows the state at the time of the fitting start of the shaft to the inner side coupling member of a constant velocity universal joint. (A) is the enlarged view of the A section of FIG. 9, (B) is the enlarged view of the B section of FIG. It is sectional drawing which shows the state at the time of the fitting start of the shaft to the inner side coupling member of the constant velocity universal joint which concerns on embodiment of this invention. (A) is the enlarged view of the A section of FIG. 11, (B) is the enlarged view of the B section of FIG. It is sectional drawing which shows the state at the time of the fitting start of the shaft to the inner joint member of the constant velocity universal joint which concerns on the modification of embodiment of this invention. (A) is the enlarged view of the A section of FIG. 13, (B) is the enlarged view of the B section of FIG.

  Hereinafter, embodiments for carrying out the present invention will be described with reference to the accompanying drawings.

  1, 3 and 5 show a constant velocity universal joint 1 and a shaft 2 connected by a spline fitting structure S according to an embodiment of the present invention. FIG. 1 shows a case where the constant velocity universal joint 1 is a double offset type sliding constant velocity universal joint (DOJ), and FIG. 3 shows a constant velocity universal joint 1 which is a Rzeppa type fixed constant velocity universal joint (BJ). FIG. 5 shows a case where the constant velocity universal joint 1 is a tripod type sliding constant velocity universal joint (TJ). 2, 4, and 6 show a state before the inner joint member 4 of the DOJ, BJ, and TJ and the shaft 2 are fitted.

  These constant velocity universal joints 1 are used, for example, in drive shafts and propeller shafts that are power transmission systems of automobiles and the like. The constant velocity universal joint 1 includes an outer joint member 3, an inner joint member 4 positioned inside the outer joint member 3, and a torque transmission member 5 that transmits torque between the outer joint member 3 and the inner joint member 4. And are the main components. As the torque transmission member 5, a ball is used for DOJ and BJ, and a roller is used for TJ. In the spline fitting structure S of the present embodiment, the shaft 2 is a shaft member, and the inner joint member 4 is a fitted member.

  One of the two shafts (not shown) on the driving side and the driven side (not shown) is connected to the outer joint member 3, and the shaft 2, which is the other of the two shafts, is connected to the inner joint member 4. A male spline 6 is formed on the outer peripheral surface of the shaft end 2 a of the shaft 2. The inner joint member 4 has a shaft hole 4a into which the shaft 2 is fitted, and a female spline 7 is formed on the inner peripheral surface of the shaft hole 4a. Then, when the shaft end 2 a of the shaft 2 is fitted into the shaft hole 4 a of the inner joint member 4, the male spline 6 and the female spline 7 are fitted, thereby connecting the inner joint member 4 and the shaft 2.

  An annular groove 8 is provided at the shaft end 2 a of the shaft 2, and a retaining ring 9 is fitted on the annular groove 8. A shoulder 2b is formed near the center of the shaft 2 near the male spline 6 in the axial direction. When the retaining ring 9 and the shoulder portion 2 b abut against the inner joint member 4, the axial displacement of the inner joint member 4 with respect to the shaft 2 is restricted. As the retaining ring 9, a snap ring is used for DOJ and TJ, and a circlip is used for BJ. The cross section of the snap ring is rectangular, and the cross section of the circlip is circular. Correspondingly, the cross-sectional shape of the annular groove 8 into which the snap ring is fitted is U-shaped, and the cross-sectional shape of the annular groove 8 into which the circlip is fitted is U-shaped. In DOJ and BJ, the annular groove 8 is provided between the axial center of the male spline 6 and the axial end (on the side of the shaft end surface 2c). In TJ, the annular groove 8 is formed in the male spline 6. Adjacent to the shaft end face 2c.

  A first chamfered portion 10 is provided at the insertion start end of the male spline 6 of the shaft 2. The first chamfered portion 10 is composed of a tapered surface formed from the male spline 6 to the shaft end surface 2c in DOJ and BJ, but is composed of a tapered surface formed in the male spline 6 in TJ. A second chamfered portion 11 is provided at the insertion start end of the female spline 7 of the inner joint member 4. The 2nd chamfer part 11 is comprised by the taper surface formed from the female spline 7 to the end surface 4b.

  The chamfering angle θ1 of the first chamfered portion 10 is 10 ° or more smaller than the chamfered angle θ2 of the second chamfered portion 11. The chamfering angle θ1 of the first chamfered portion 10 is 15 to 25 °, and the chamfered angle θ2 of the second chamfered portion 11 is 25 to 60 °. This effect will be described below with reference to the drawings.

  First, as a comparison, the case where the chamfering angle θ1 = the chamfering angle θ2 will be described by taking the DOJ inner joint member 4 and the shaft 2 as an example. In this case, as shown in FIG. 7, when the center axis of the male spline 6 is slightly inclined with respect to the center axis of the female spline 7 as shown in FIG. That is, as shown in FIGS. 8 (A) and 8 (B), both the A portion and the B portion in FIG. 7 are enlarged at the corners on the inner peripheral side end in the second chamfered portion 11 of the female spline 7 of the inner joint member 4. The portion C2 (the corner portion formed by the second chamfered portion and the female spline 7 small diameter portion) contacts (or opposes) only a part of the shaft 2. Therefore, even if the inner joint member 4 and the shaft 2 are rotated relative to each other for phase matching, there is little opportunity for the tooth surfaces of the female spline 7 of the inner joint member 4 and the male spline 6 of the shaft 2 to mesh. In particular, in the portion B, the tooth surface of the corner portion C2 of the female spline 7 of the inner joint member 4 is in contact with a portion that is not the tooth surface of the male spline 6 of the shaft 2, and it is difficult to engage with each other. For this reason, in the spline fitting structure in which the chamfering angle θ1 = the chamfering angle θ2, the fitting operation is not sufficiently easy.

  Next, the case where the chamfering angle θ1> the chamfering angle θ2 will be described by taking the inner joint member 4 and the shaft 2 of BJ as an example. In this case, the relationship between the shaft 2 and the inner joint member 4 is reversed with respect to the case of the above-described DOJ. That is, at the start of insertion, if the center axis of the male spline 6 is slightly inclined with respect to the center axis of the female spline 7 as shown in FIG. As shown in FIGS. 10A and 10B in an enlarged manner, both the A part and the B part in FIG. The chamfered portion and the corner portion formed by the large diameter portion of the male spline 6 abut (or face) only a part of the inner joint member 4. Therefore, even if the inner joint member 4 and the shaft 2 are rotated relative to each other for phase matching, there is little opportunity for the tooth surfaces of the female spline 7 of the inner joint member 4 and the male spline 6 of the shaft 2 to mesh. In particular, in B part, the tooth surface in the corner | angular part C1 of the male spline 6 of the shaft 2 is contacting the part which is not the tooth surface of the female spline 7 of the inner joint member 4, and it is difficult to mesh. For this reason, in the spline fitting structure where the chamfering angle θ1> the chamfering angle θ2, the fitting operation is not sufficiently easy.

  In contrast to these spline fitting structures, in the spline fitting structure S of the present invention, the chamfering angle θ1 <the chamfering angle θ2. The spline fitting structure S of the present invention will be described using DOJ as an example. FIG. 11 shows a state where the central axis of the male spline 6 is slightly inclined with respect to the central axis of the female spline 7 at the start of insertion. As shown in FIGS. 12 (A) and 12 (B) in an enlarged manner, both the A portion and the B portion in FIG. However, it contacts (or faces) the male spline 6 of the shaft 2. Therefore, when the inner joint member 4 and the shaft 2 are rotated relative to each other for phase matching, the tooth surface of the corner C2 of the female spline 7 of the inner joint member 4 and the tooth surface of the male spline 6 of the shaft 2 are obtained. Is easy to mesh. For this reason, compared with the above-mentioned spline fitting structure, in the spline fitting structure S of this invention, a fitting operation becomes easy.

  Further, in the spline fitting structure of the constant velocity universal joint and the shaft, the chamfer angle is not set as in the spline fitting structure S of the present invention. A chamfered portion corresponding to the two chamfered portion 11 is provided. Therefore, the product of the present invention can be implemented by changing the chamfering angle between the existing constant velocity universal joint and the chamfered portion of the shaft. For this reason, it is possible to make the length of the tip of the shaft 2 protruding from the inner joint member 4 after insertion almost equal to the conventional one, and even if the length of the tip of the shaft 2 is increased, The amount of increase can be suppressed.

  A modification of the spline fitting structure S of the present embodiment is shown in FIG. FIG. 13 shows a state where the central axis of the male spline 6 is slightly inclined with respect to the central axis of the female spline 7 at the start of insertion. In this modification, as shown in an enlarged view in FIGS. 14A and 14B, the inner peripheral side corner C <b> 2 of the second chamfered portion 11 of the inner joint member 4, that is, the inner peripheral side corner of the female spline 7. C2 is rounded. Thus, when the inner peripheral side corner C2 of the female spline 7 is rounded, the periphery of the inner peripheral side corner C2 is compared with the case where the inner peripheral side corner C2 of the female spline 7 is rounded. This makes it easier for the portion to abut (or face) the male spline of the shaft 2. Therefore, when the inner joint member 4 and the shaft 2 are rotated relative to each other for phase alignment, the tooth surface of the peripheral portion of the inner peripheral corner C2 in the female spline 7 of the inner joint member 4 and the male shaft 2 The tooth surface with the spline 6 is easy to mesh. Therefore, in the spline fitting structure S of this modified example, the fitting operation is further facilitated.

  In addition, as a curvature radius of corner | angular part C2 which makes the above-mentioned round shape, it shall be about 1-3 mm, for example. When the radius of curvature is less than 1 mm, the radius of curvature is too small, so that the effect of facilitating the fitting work cannot be sufficiently exhibited. On the other hand, as the radius of curvature increases, it becomes increasingly difficult to engage the tooth surfaces, so it is desirable that the radius of curvature does not exceed 3 mm.

  In order to evaluate the spline fitting structure according to the present invention, the present inventors have developed a spline fitting structure having a first chamfered portion 10 and a second chamfered portion 11 having various chamfering angles to a female spline of a male spline. The ease of insertion work was investigated. The survey results are shown in Table 1. In the evaluation of Table 1, the symbol ◯ means very easy, the symbol Δ means somewhat easy, and the symbol × means not easy.

  In Table 1, it can be understood that in the region indicated by ◯, the chamfering angle of the first chamfered portion 10 is 15 to 25 ° and the chamfered angle of the second chamfered portion 11 is 25 to 60 °. Further, in this region, it can be understood that the chamfering angle of the first chamfered portion 10 is smaller than the chamfered angle of the second chamfered portion by 10 ° or more. These conditions are consistent with the configuration of the spline fitting structure of the present invention. That is, it can be said from the investigation results of Table 1 that according to the configuration of the spline fitting structure of the present invention, the operation of fitting the male spline into the female spline is very easy.

  In the above embodiment, the constant velocity universal joint 1 is a Rzeppa type fixed constant velocity universal joint, a double offset type, or a tripod type sliding constant velocity universal joint, but the present invention is not limited to this. For example, a fixed type constant velocity universal joint such as an undercut free type may be used, or a sliding type constant velocity universal joint such as a cross groove type may be used.

  Furthermore, in the above embodiment, the shaft 2 of the power transmission system of the automobile and the inner joint member 4 of the constant velocity universal joint 1 are used as the shaft member and the fitted member, respectively, but the present invention is limited to this. Instead, it is sufficient if spline fitting is performed. For example, a shaft and a universal joint of a power transmission system such as an industrial machine may be used as a shaft member and a fitted member, respectively.

1 Constant velocity universal joint 2 Shaft (shaft member)
2b shoulder 4 inner joint member (inserted member)
6 male spline 7 female spline 9 retaining ring 10 first chamfered portion 11 second chamfered portion S spline fitting structure θ1 chamfered angle of the first chamfered portion θ2 chamfered angle of the second chamfered portion C1 outer peripheral side corner of the first chamfered portion C2 Inner peripheral corner of the second chamfer

Claims (6)

A shaft member provided with a male spline on the outer peripheral surface; and a fitted member provided with a female spline capable of fitting the male spline on the inner peripheral surface; In the spline fitting structure in which the first chamfered portion is provided and the second chamfered portion is provided at the insertion start end of the female spline of the inserted member,
The fitted member is an inner joint member of a constant velocity universal joint, and the shaft member is a shaft fitted into the inner joint member,
The chamfer angle of the first chamfered portion is made 10 ° or less smaller than the chamfer angle of the second chamfered portion,
The spline fitting structure, wherein a chamfering angle of the first chamfered portion is set to 15 to 25 °, and a chamfered angle of the second chamfered portion is set to 25 to 60 °.   The spline fitting structure according to claim 1, wherein an inner peripheral side corner portion of the second chamfered portion is rounded. Constant velocity universal joint having a spline fitting structure according to 請 Motomeko 1 or 2. The constant velocity universal joint according to claim 3, wherein the axial displacement of the inner joint member with respect to the shaft is regulated by a shoulder portion of the shaft and a retaining ring externally fitted to the shaft.   The constant velocity universal joint according to claim 3, wherein the constant velocity universal joint is a fixed type constant velocity universal joint.   The constant velocity universal joint according to claim 3, wherein the constant velocity universal joint is a sliding type constant velocity universal joint.

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