JP6561681B2 - Constant velocity joint boots - Google Patents

Description

  The present invention relates to a boot for a constant velocity joint that connects a first shaft member and a second shaft member.

  The constant velocity joint is a joint that transmits power from a drive shaft (input shaft) to a driven shaft (output shaft). For example, the constant velocity joint is incorporated in a power transmission system in an automobile and is disposed on the road surface side of the vehicle body.

  Here, the constant velocity joint is disposed at the outer end member of the bottomed cylindrical body provided at one end of the drive shaft and the distal end portion of the driven shaft, and is inserted into the outer member through the opening of the outer member. And an inner member. Then, the boot is mounted from the outer member to the driven shaft. A grease composition is enclosed in the boot. The boot has a sealing function of preventing the grease composition from leaking and preventing foreign matters such as water and sludge from entering the boot from the outside.

  In such a constant velocity joint, stones and the like that are flipped up by the tire may collide with the boot while the vehicle is traveling. Therefore, it is necessary to avoid damage to the boot due to an impact at this time. For example, Patent Literature 1 discloses that the inner peripheral surface of the boot is spaced radially outward from the opening side end portion of the outer member to form a space portion therebetween. According to the description of Patent Document 1, when a scattered stone or the like collides with the boot, the impact of the collision can be absorbed through the space portion, so that the boot is at the corner of the opening side end of the outer member. It is possible to effectively prevent damage to the boot without contact.

JP 2003-214457 A

  By the way, according to the proposal of Patent Document 1, as described above, when the space is provided between the inner peripheral surface of the boot and the opening side end of the outer member, when the constant velocity joint is swung, that is, the drive shaft When the angle between the shaft and the driven shaft changes, a bending force (bending stress) is strongly applied in the vicinity of the connection portion between the boot and the outer member, and the possibility of damage to the boot increases.

  Therefore, the present invention has been devised in view of such a point, and an object thereof is to more suitably avoid boot damage in a constant velocity joint.

According to one aspect of the invention,
A boot for a constant velocity joint that connects a first shaft member and a second shaft member, the boot being mounted on an outer peripheral surface of an outer member provided at an end of the first shaft member using a tightening member In
The boot is formed such that the first inner peripheral surface portion and the second inner peripheral surface portion are alternately arranged in the circumferential direction around the end portion of the outer member located on the second shaft member side of the fastening member. Have been
Each first inner peripheral surface portion is configured to form a space portion with the outer member apart from the outer peripheral surface of the end portion of the outer member,
Each of the second inner peripheral surface portions is configured to be positioned closer to the outer peripheral surface than the adjacent first inner peripheral surface portions.
A boot for a constant velocity joint is provided.

  According to the one aspect of the present invention, the boot can form a space portion with the outer member by the first inner peripheral surface portion around the end portion of the outer member. Can absorb shocks. Further, around the end portion of the outer member, the boot has a second inner peripheral surface portion closer to the outer peripheral surface of the end portion of the outer member than the first inner peripheral surface, and each second inner peripheral surface portion is Located between the first inner peripheral surface portions. Therefore, when the constant velocity joint is swung, at least one second inner peripheral surface portion is close to or in contact with the outer peripheral surface of the outer member, and in some cases, continues to contact from before, so there is no second inner peripheral surface portion. As compared with the above, the rigidity around the tightening portion by the tightening member is increased from the first inner peripheral surface portion of the boot. Therefore, when the constant velocity joint is swung, the deformation of the boot around the end portion of the outer member is suppressed, and the space can be kept more than a certain level. Therefore, according to the one aspect of the present invention, it is possible to prevent the boot from being damaged by stones or the like by providing the first inner peripheral surface portion, and the second inner space portion between the first inner peripheral surface portions. By providing the inner peripheral surface portion, it is possible to firmly support the boot when the constant velocity joint is swung, and to effectively prevent the boot from being damaged due to deformation or the like.

It is an external view of the constant velocity joint provided with the boot which concerns on embodiment of this invention. FIG. 2 is an enlarged partial cross-sectional view of a connection portion between a boot and an outer member of the constant velocity joint of FIG. 1 taken along line II-II of FIG. FIG. 3 is an enlarged sectional view of a part of the constant velocity joint of FIG. 1 taken along the line III-III of FIG. 2.

  A constant velocity joint to which a boot according to an embodiment of the present invention is applied will be described in detail with reference to the drawings.

  FIG. 1 is an external view of a constant velocity joint 10 according to an embodiment. Here, first, the overall configuration of the constant velocity joint will be described.

  The constant velocity joint 10 is a joint that connects two shaft members. The constant velocity joint 10 includes an outer member (outer race) 12 provided at one end of a drive shaft (first shaft member) and an inner member (not shown) inserted into the outer member 12. The outer member 12 is provided with an opening 12a and has a bottomed cylindrical shape. The inner member is provided at one end of the driven shaft (second shaft member) 14.

  The inner member is positioned and fixed to the side peripheral wall of the driven shaft 14, and the tip of the inner member is slidably inserted into a guide groove provided on the inner peripheral wall (inner peripheral surface) of the outer member 12. The driven shaft 14 is thereby connected to the constant velocity joint 10 and can take various angles with respect to the drive shaft.

  Further, in the constant velocity joint 10, a boot 18 is mounted so as to cover the outer periphery from the end 12 a side end (end on the driven shaft 14 side) 12 b of the outer member 12 to the end of the driven shaft 14. . The boot 18 has a large-diameter cylindrical portion 20 having an opening diameter corresponding to the outer diameter of the outer member 12 at one end thereof, and a small-diameter cylindrical portion 22 into which the driven shaft 14 is inserted. The boot 18 is made of resin here, but the material is not limited.

  On the outer periphery of the large-diameter cylindrical portion 20, an annular first mounting groove 24 that is depressed in the radial direction with a predetermined width (in the longitudinal direction or the axial direction of the boot) is formed. A first tightening band (tightening member) 26 is attached to the first attachment groove 24 so that the boot 18 is attached to the outer peripheral surface of the outer member 12. On the other hand, an annular second mounting groove 28 that is depressed with a predetermined width is also formed on the outer periphery of the small-diameter cylindrical portion 22, and the second tightening band 30 is mounted in the second mounting groove 28. As a result, the large diameter cylindrical portion 20 is fastened to the outer peripheral surface near the opening end of the outer member 12 using the first tightening band 26, and the small diameter cylindrical portion 22 is driven using the second tightening band 30. 14 is tightened to the outer peripheral surface.

  The boot 18 is pre-filled with a grease composition. More specifically, before the outer member 12 and the driven shaft 14 are inserted into the large-diameter cylindrical portion 20 and the small-diameter cylindrical portion 22, respectively, the grease composition is prefilled therein. This grease composition is enclosed in the boot 18 by fastening the first fastening band 26 and the second fastening band 30 as described above.

  Now, in the boot 18, crests and valleys are alternately continuous between the large-diameter cylindrical portion 20 and the small-diameter cylindrical portion 22, and the diameter is reduced from the large-diameter cylindrical portion 20 toward the small-diameter cylindrical portion 22. The bellows portion 36 is interposed.

  The bellows portion 36 of the boot 18 includes an annular wall portion 38 (as a kind of mountain portion) and a first annular mountain portion 40a to a fourth annular mountain from the large diameter cylindrical portion 20 side toward the small diameter cylindrical portion 22 side. A portion 40d is formed. And between the annular wall 38 and the first annular ridge 40a, between the first annular ridge 40a and the second annular ridge 40b, and between the second annular ridge 40b and the third annular ridge 40c. The first annular valley portion 42a to the fourth annular valley portion 42d are interposed between the third annular peak portion 40c and the fourth annular peak portion 40d, respectively.

  The boot 18 having the above-described configuration has a characteristic configuration in the annular wall portion 38. The annular wall portion 38 is formed in the first mounting groove 24 (that is, the tightening portion) in which the first tightening band 26 is mounted on the small diameter cylindrical portion 22 side (that is, on the driven shaft 14 side of the first tightening band 26). It is a portion that is adjacent and extends so as to protrude (or rise) in the radial direction (which is a direction substantially orthogonal to the longitudinal direction) from the first mounting groove 24 as a whole. Therefore, the boot 18 includes a rising wall portion 38 a that extends in the substantially radial direction from the small-diameter cylindrical portion 22 side of the first mounting groove 24 with respect to the annular wall portion 38. Here, FIG. 2 shows a partial cross-sectional view of the connecting portion between the large-diameter cylindrical portion 20 and the outer member 12 along the longitudinal direction of the boot 18 (II-II line in FIG. 1). Further, FIG. 3 shows a partial cross-sectional view of the connecting portion between the large-diameter cylindrical portion 20 and the outer member 16 along the line III-III in FIG.

  As shown in FIGS. 2 and 3, the annular wall portion 38 of the boot 18 has a first periphery around the opening end 12 b (located on the driven shaft 14 side of the first fastening band 26) of the outer member 12. The inner peripheral surface portion 18a and the second inner peripheral surface portion 18b are formed so as to be alternately arranged on the inner peripheral surface in the circumferential direction. Therefore, the annular wall portion 38 of the boot 18 includes a plurality of first inner peripheral surface portions 18a and a plurality of second inner peripheral surface portions 18b, and the number thereof is the same. However, this invention does not ask | require each number of the 1st internal peripheral surface part 18a and the 2nd internal peripheral surface part 18b. The first inner peripheral surface portion 18 a and the second inner peripheral surface portion 18 b extend over substantially the entire annular wall portion 38 in the longitudinal direction of the boot 18, respectively. In FIG. 2, a second inner peripheral surface portion 18 b that is located at a position shifted from the first inner peripheral surface portion 18 (along the II-II line in FIG. 1) to the back side in the circumferential direction in the circumferential direction is shown. In addition, the 2nd inner peripheral surface part 18b is not limited to extending over the whole longitudinal direction of the cyclic | annular wall part 38, You may extend only to a part of the longitudinal direction.

  The first inner peripheral surface portion is separated from the outer peripheral surface 12 c of the opening-side end portion 12 b of the outer member 12 when the outer member 12 is inserted into the large-diameter cylindrical portion 20. As a result, the space 44 is provided between the opening-side end 12 b of the outer member 12 and the annular wall 38.

  On the other hand, when the outer member 12 is inserted into the large-diameter cylindrical portion 20, the second inner peripheral surface portion 18b is closer to the outer peripheral surface 12c of the opening side end portion 12b of the outer member 12 than the adjacent first inner peripheral surface portions 18a. In some cases, the outer peripheral surface 12c can be contacted. However, the second inner peripheral surface portion is formed with a narrow contactable area with the outer member 12 so as to ensure a wide space 44. In other words, in the annular space portion between the annular wall portion 38 of the boot 18 and the opening side end portion 12b of the outer member 12, each second inner support is formed so as to form a plurality of boot support portions at substantially equal intervals in the circumferential direction. The peripheral surface portion 18b is formed so as to hang down to the outer member 12 side from a virtual extended cylindrical surface (not shown) determined so as to connect the plurality of first inner peripheral surface portions 18a. And in this embodiment, since the boot 18 is manufactured by blow molding, it is formed so that it may have substantially the same thickness as a whole. Therefore, the annular wall portion 38 of the boot 18 includes the recessed portions 46 on the outer peripheral surface thereof at substantially equal intervals in the circumferential direction (outside in the radial direction of the related second inner peripheral surface portion). Therefore, the annular wall portion 38 has an uneven shape corresponding to each other on the inner peripheral side and the outer peripheral side in the circumferential direction. Note that each recess extends in the longitudinal direction of the annular wall 38.

  The first inner peripheral surface portion 18a is formed so as to extend from the outer peripheral surface 12c of the opening side end portion 12b to a position at a distance L1, and this distance L1 is not less than a first distance L1 ′ (not shown). The first distance L1 ′ is determined so that the first inner peripheral surface portion 18a of the boot 18 and the outer peripheral surface of the opening side end portion 12b of the outer member 12 when the drive shaft and the driven shaft 14 are arranged substantially linearly. It is determined to be apart from 12c and to form a desired minimum size space between them. For example, the first distance L1 ′ can be determined as the minimum distance that can suitably absorb the impact when pebbles or the like collide with the boot. The second inner peripheral surface portion 18b is formed to be located at a distance L2 from the outer peripheral surface 12c of the opening side end portion 12b. This distance L2 is set to be equal to or less than a second distance L2 ′ (not shown). Here, when the drive shaft and the driven shaft 14 are arranged in a substantially linear shape, the distance L2 is substantially a value close to 0 (≠ 0). Is set. The second distance L2 ′ is determined when the angle between the drive shaft and the driven shaft in the constant velocity joint changes, that is, when the constant velocity joint swings, the first inner peripheral surface portion 18a of the boot 18 and the outer member. The second inner peripheral surface portion 18b or the periphery thereof exhibits a support function of the annular wall portion 38 so that the space portion 44 between the 12 opening-side end portions 12b and the outer peripheral surface 12c can be held to a certain extent. It can be defined as a maximum value. Therefore, the distance L2 can be any value greater than or equal to 0, but is shorter than the first distance L1 ′. Note that the second distance L2 ′ is shorter than the first distance L1 ′ (L1 ′> L2 ′).

  Further, even when the constant velocity joint is swung, the boot 18 is separated from the edge portion 12d located at the end in the longitudinal direction of the opening side end portion 12b of the outer member 12 in the longitudinal direction. In addition, the annular wall 38 is dimensioned and / or shaped. Therefore, in FIG. 2 (in the constant velocity joint 10 in which the drive shaft and the driven shaft 14 are arranged substantially linearly), the boot 18 extends from the longitudinal edge 12d of the outer member 12 in the longitudinal direction (even at the nearest portion). ) Leave distance L3.

  With respect to the constant velocity joint of the present embodiment having the above-described configuration, the operational effects will be described below.

  First, the annular wall portion 38 of the boot 18 includes a plurality of the first inner peripheral surface portions 18a in the circumferential direction. As a result, the space 44 is formed around the opening-side end 12b of the outer member 12. Therefore, when a scattered stone or the like collides with the boot 18 (that is, when an external force is applied), the impact of the collision can be absorbed through the space 44. Therefore, the boot 18 does not come into contact with the opening side end portion 12b of the outer member 12, and damage to the boot 18 can be effectively prevented.

  Further, the annular wall portion 38 of the boot 18 includes a plurality of the second inner peripheral surface portions 18b in the circumferential direction. The second inner peripheral surface portion 18b is generally closer to the outer member 12 than the first inner peripheral surface portion 18a, and in some cases, is in contact therewith. This is the same when the constant velocity joint 10 swings (that is, when the boot is deformed). When the amount of deformation of the boot exceeds a certain level, at least one second inner peripheral surface portion 18b and preferably the plurality of second inner peripheral surface portions 18b are in contact with the outer peripheral surface 12c. Accordingly, the annular wall portion 38 is entirely supported by the contact, and bending stress applied to the rising wall portion 38a from the first mounting groove 24 in the annular wall portion 38 is suppressed. Therefore, it can suppress more suitably that the boot 18 is damaged (for example, a crack enters) in the part of the 1st mounting groove 24 from the annular wall part 38. FIG.

  Further, as described above, the annular wall portion 38 of the boot 18 includes a plurality of recessed portions 46 in the circumferential direction, and includes a plurality of second inner peripheral surface portions 18b. That is, the annular wall portion 38 has a shape in which irregularities are repeated in the circumferential direction on both the inner peripheral side and the outer peripheral side. Therefore, the space portion rigidity is appropriately improved by these, and when the constant velocity joint 10 is swung, the plurality of space portions 44 can be supported more firmly without obstructing the rocking. The above effects can be maintained.

  Although one embodiment of the present invention has been described above, various modifications can be made. For example, in the boot 18 of the constant velocity joint 10, the recessed portion 46 is formed on the outer peripheral surface of the boot so as to form the second inner peripheral surface portion 18b. However, the recess may not be formed. That is, the annular wall portion 38 of the boot 18 may have a smooth cylindrical outer peripheral surface corresponding only to the first inner peripheral surface portion 18a. However, since the boots may be manufactured by blow molding, the boots may have substantially the same thickness as in the above embodiment. In addition, this invention does not limit the manufacturing method of boots.

  Further, in the constant velocity joint 10, at least one second inner peripheral surface portion 18 b could be in contact with the outer peripheral surface of the outer member 12 when swinging. However, all the second inner peripheral surface portions 18b may continue to be separated from the outer peripheral surface of the outer member 12 when the constant velocity joint is swung. Also in this case, since the rigidity is increased by the wall surface portion extending between the first inner peripheral surface portion 18a and the second inner peripheral surface portion 18b, a certain degree of support function can be exhibited, and thus the above-described effect is brought about. Can do. Of course, this invention does not ask | require when each 2nd inner peripheral surface part 18b contacts the outer peripheral surface of the outer member 12. FIG.

  In addition, this invention does not limit the constant velocity joint applied to a specific thing. The present invention can be applied to a tripart type (that is, sliding type) constant velocity joint or a fixed type constant velocity joint.

  Embodiments of the present invention are not limited to the embodiments described above. All modifications, applications, and equivalents included in the spirit of the present invention defined by the claims are included in the present invention.

10 constant velocity joint 12 outer member 12a opening 12b opening side end 12c outer peripheral surface 14 driven shaft (second shaft member)
18 Boot 18a 1st inner peripheral surface part 18b 2nd inner peripheral surface part 36 Bellows part 38 Annular wall part 44 Space part 46 Recessed part

Claims (1)

A boot for a constant velocity joint that connects a first shaft member and a second shaft member, the boot being mounted on an outer peripheral surface of an outer member provided at an end of the first shaft member using a tightening member In
The boot is formed such that the first inner peripheral surface portion and the second inner peripheral surface portion are alternately arranged in the circumferential direction around the end portion of the outer member located on the second shaft member side of the fastening member. Have been
Each first inner peripheral surface portion is configured to form a space portion with the outer member apart from the outer peripheral surface of the end portion of the outer member,
Each second inner peripheral surface portion is configured to be located closer to the outer peripheral surface than the first inner peripheral surface portion on both sides,
Each first inner peripheral surface portion and each second inner peripheral surface portion are adjacent to the second shaft member side of the tightening portion to be tightened by the tightening member, and at least each first inner peripheral surface portion is the outer member It is formed so as to extend away from the edge located at the end in the most longitudinal direction among the ends toward the second shaft member side ,
At least each first inner peripheral surface portion and each second inner peripheral surface portion and the corresponding portion connecting the inner peripheral surface portions are formed to have the same thickness as a whole.
Boots for constant velocity joints.

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