JP2011252594A - Boot band - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a boot band capable of improving assemblability and sealing properties in the boot band employing a lever.SOLUTION: The boot band has a band body 24 formed in the ring part 23 by bonding ends 21, 22 and a circular-shaped lever 26 attached to an outer diameter face of the bonding part 25 of the band body 24. The lever 26 is folded back such that the inner face 30 which is a concave curved face is lapped on the outer diameter face of the band body 24. Thus diameter of the ring 23 of the band body 24 is contracted to fasten the band installing part of the boot 3 for a constant velocity universal joint outwardly fitted by the ring part 23. The diametrical size of the inner face 30 which is the concave curved face of the lever 26 is made larger than the diametrical size of the outer diameter of the ring part 23 when the diameter is contracted.

Description

  The present invention relates to a boot band for fixing a boot for a constant velocity universal joint mounted on a sliding type or a fixed type constant velocity universal joint for power transmission of automobiles and various industrial machines.

  As this type of boot band, there is a so-called lever type as described in Patent Document 1 or the like. As shown in FIG. 6, this lever-type boot band has a metal band member (band main body) 51 formed in a ring shape, and an overlapping portion (joint portion) 52 having an arc shape. A lever 53 is provided.

  This boot band is fitted on the band mounting portion (not shown) of the constant velocity universal joint boot, and the lever 53 is tilted in the direction of the arrow in FIG. 6 using the lever principle. Thereby, the ring part 54 in the band main body 51 is reduced in diameter, and the band mounting part can be tightened by the boot band. Thus, by tightening the band mounting portion, the band mounting portion can be fixed to the outer joint member of the constant velocity universal joint or the shaft fitted into the inner joint member of the constant velocity universal joint. The tilted lever 53 is fixed to a stopper 55 attached to the band main body 51.

Japanese Patent Laid-Open No. 50-14702

  When the boot band as shown in FIG. 6 is attached, the inner surface 53 a of the lever 53 is overlapped with a part of the outer surface 54 a of the ring portion 54. However, as shown in FIG. 7, when the diameter R of the inner surface 53a of the lever 53 is smaller than the diameter R1 of the outer surface 54a of the ring portion 54, the gap between the inner surface 53a of the lever 53 and the outer surface 54a of the ring portion 54 is reduced. A gap 60 is formed in the gap.

  If such a gap 60 is formed, the assembling property and the sealing property are deteriorated. The constant velocity universal joint boot is for sealing the constant velocity universal joint, and it is not preferable that the sealing performance deteriorates.

  The subject of this invention proposes the boot band which can aim at the improvement of an assembly | attachment property and a sealing performance in the boot band using a lever.

  The boot band of the present invention includes a band main body formed at the ring portion by joining the end portions, and an arc-shaped lever attached to the outer diameter surface of the joint portion of the band main body. A constant velocity universal joint boot in which a ring portion of the band main body is reduced in diameter by being folded back so that an inner surface which is a concave curved surface is overlapped with an outer diameter surface of the band main body. This is a boot band for tightening the band mounting part, and the diameter of the inner surface, which is the concave curved surface of the lever, is made larger than the diameter of the outer diameter when the ring part is contracted.

  In the boot band of the present invention, the diameter of the inner surface, which is the concave curved surface of the lever, is larger than the diameter of the outer diameter when the ring portion is contracted, so the gap between the inner surface of the lever and the outer diameter surface of the ring portion. It is difficult to form a gap.

  Preferably, the band main body is provided with a protrusion that fills the gap at the end portion on the lever folding side that occurs when the lever is superimposed on the band main body. By providing this projection, the band mounting portion of the boot can be tightened with a substantially uniform tightening force over the entire circumference.

  The band body may be a rectangular cross section with rounded chamfers at four corners or a rectangular cross section with square chamfered at four corners.

  The constant velocity universal joint boot may be a rubber boot made of chloroprene rubber or silicon rubber. At this time, the surface hardness is preferably Hs50 to Hs70. The constant velocity universal joint boot may be a resin boot made of a thermoplastic polyester elastomer or a composition containing a thermoplastic polyester elastomer. At this time, the surface hardness is preferably HDD38 to HDD50.

  In the present invention, it is difficult to form a gap between the inner surface of the lever and the outer diameter surface of the ring portion, so that the stable assembly state of the band can be maintained, the sealing performance can be improved, and the constant velocity universal joint The boot can be stably fixed over a long period of time.

  When the band body is provided with a protrusion that fills the gap on the end side of the lever folding side, the band mounting part of the boot can be tightened with a substantially uniform tightening force over the entire circumference. Further improvements can be achieved.

  In the case where chamfering is applied, stress concentration at the corner of the band body can be prevented, and the band mounting portion of the constant velocity universal joint boot fastened by this band does not bite into the corner of the band body. Damage to the universal joint boot and the band body can be effectively prevented.

  The constant velocity universal joint boot as the fixed member may be a rubber boot or a resin boot, and is excellent in versatility. In the case of a rubber boot, if the surface hardness is smaller than Hs50, the strength of the boot is reduced, and conversely if the surface hardness is larger than Hs70, the fatigue property is reduced. For this reason, it is preferable that the surface hardness is Hs50 to Hs70.

  In the case of a resin boot, if it is smaller than the HDD 38, the heat resistance is lowered, the cost of the boot is increased, and the strength is lowered. Conversely, if the surface hardness is larger than the HDD 50, the fatigue, flexibility, and assemblability are reduced. Incurs a decline. For this reason, it is preferable that surface hardness is HDD38-HDD50.

It is a front view before the fastening of the boot band which shows embodiment of this invention. It is a front view of the tightening state of the boot band. It is sectional drawing of the constant velocity universal joint using the said boot band. The boot band is shown, (a) is an enlarged cross-sectional view when round chamfering is performed at four corners, and (b) is an enlarged cross-sectional view when square chamfering is applied at four corners. It is a front view of the tightening state of the boot band which shows other embodiment of this invention. It is a front view before the fastening of the conventional boot band. It is a front view of the tightening state of the boot band shown in the said FIG.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  1 and 2 show a boot band of the present invention. This boot band 1 is used to fix a constant velocity universal joint boot 3 attached to a constant velocity universal joint 2 as shown in FIG. The constant velocity universal joint 2 includes an outer joint member 7 having a track groove 6 formed on the inner diameter surface 5, an inner joint member 10 having a track groove 9 formed on the outer diameter surface 8, and the track groove 6 of the outer joint member 7. And a ball 11 for transmitting torque and interposed between the track groove 9 of the inner joint member 10 and a cage 12 having a pocket for accommodating the ball 11.

  A female spline 13 is formed on the inner diameter surface of the inner joint member 10, and the end of the shaft 15 is fitted into the inner joint member 10. A male spline 14 is formed at the end of the shaft 15, and the male spline 14 is fitted to the female spline 13 on the inner diameter surface of the inner joint member 10.

  The boot 3 is a resin boot in this embodiment, and includes a large diameter portion 3a, a small diameter portion 3b, and a bellows portion 3c disposed between the large diameter portion 3a and the small diameter portion 3b. A large-diameter portion 3a as a band mounting portion is fitted on a boot mounting portion 16 formed on the opening side of the outer diameter surface of the outer joint member 7, and the large-diameter portion 3a is tightened by the boot band 1 according to the present invention. It is done. Further, a boot mounting portion 17 is formed on the shaft 15, and a small diameter portion 3 b as a band mounting portion is externally fitted to the boot mounting portion 17 of the shaft 15, and the small diameter portion 3 b is formed in the boot band 1 according to the present invention. Tightened. The resin boot is formed of, for example, a composition containing a thermoplastic elastomer such as ester, olefin, urethane, amide, or styrene, or a thermoplastic polyester elastomer. Thermoplastic elastomers have intermediate properties between resin and rubber, and are excellent in durability such as fatigue and wear, heat aging resistance, and oil resistance.

  As shown in FIGS. 1 and 2, the boot band 1 is attached to a band main body 24 formed at the ring portion 23 by joining the end portions 21 and 22, and an outer diameter surface of the joint portion 25 of the band main body 24. Arc-shaped lever 26. The band main body 24 is made of, for example, a strip-shaped member made of sheet metal. The lever 26 is made of a metal that is thicker and more rigid than the band body 24.

  That is, the inner surface 21 a and the inner surface 22 a of the other end 22 are bonded (adhered) to one end 21 to form a bonded portion (overlapping portion) 25. Further, the base end portion 27 a of the outer diameter surface (convex surface) 27 of the arc-shaped lever 26 is joined (adhered) to the outer diameter surface of the joint portion 25, that is, the outer diameter surface of the other end portion 22. The band body 24 is provided with a stopper 28 for fixing the lever 26 in order to maintain a tightening state to be described later.

  As described above, when the resin boot is used, the surface hardness is preferably set to HDD38 to HDD50. For example, a thermoplastic polyester elastomer (trade name: Hytrel (manufactured by DuPont)) having a surface hardness of HDD 47 is suitable. If the surface hardness is smaller than the HDD 38, the heat resistance will be lowered, the boot cost will be increased, and the strength will be reduced. Conversely, if the surface hardness is larger than the HDD 50, the fatigue, flexibility and assembly will be reduced. Invite you.

  The boot 3 may be a rubber boot formed of a rubber material such as chloroprene rubber or silicon rubber. When rubber boots are used, the surface hardness is preferably Hs50 to Hs70 corresponding to the surface hardness of the rubber boots. In the case of a rubber boot, if the surface hardness is smaller than Hs50, the strength of the boot is lowered, and conversely if the surface hardness is larger than Hs70, the fatigue property is lowered.

  As shown in FIGS. 4A and 4B, the band main body 24 is a rectangular section having chamfers 29 at four corners. When forming the chamfer 29, it may be a round chamfer 29a as shown in FIG. 4A or a square chamfer 29b as shown in FIG. 4B.

  Next, a method for fixing the boot with the boot band 1 will be described. When the large-diameter portion 3a of the boot 3 is fixed, the state shown in FIG. 1, that is, the ring portion 23 is not reduced in diameter without tilting the lever 26 is used. The boot band 1 is externally fitted to the large-diameter portion 3 a by being externally fitted to the boot mounting portion 16 of the outer joint member 7. When the small diameter portion 3b of the boot 3 is fixed, the state shown in FIG. 1, that is, the ring portion 23 is not reduced in diameter without tilting the lever 26, the boot mounting portion 17 of the shaft 15 The small diameter portion 3b is externally fitted, and the boot band 1 is externally fitted to the small diameter portion 3b.

  Next, the lever 26 of each boot band 1 is swung from the state shown in FIG. 1 in the direction of arrow A around the base end 26a. Along with this swinging, the overlapping portion 25 is pulled in the direction of arrow A, and the ring portion 23 is reduced in diameter as shown in FIG. Then, the inner surface 30 which is a concave curved surface of the lever 26 is overlapped with the outer diameter surface 23 a of the ring portion 23, and the tip portion of the lever 26 is fixed to the stopper 28. Thereby, the large diameter portion 3 a of the boot 3 is fixed to the boot mounting portion 16 of the outer joint member 7, and the small diameter portion 3 b of the boot 3 is fixed to the boot mounting portion 17 of the shaft 15.

By the way, in the present invention, the inner diameter dimension (radial dimension) of the inner surface 30 of the lever 26 is made larger than the outer diameter dimension (radial dimension) of the ring portion 23 in the reduced diameter state as shown in FIG. That is, when the inner diameter dimension (radius dimension) of the inner surface 30 of the lever 26 is R, the inner diameter dimension (radius dimension) of the ring portion 23 in the reduced diameter state is D, and the thickness dimension of the band body 24 is t. The relationship shown in the following equation 1 is obtained.

  In this case, since the diameter dimension (inner diameter dimension) of the inner surface 30 that is the concave curved surface of the lever 26 is larger than the outer diameter diameter (inner diameter dimension) of the ring portion 23 when the diameter is reduced, the inner surface of the lever 26 is increased. A gap as shown in FIG. 7 is unlikely to be formed between 30 and the outer diameter surface 23 a of the ring portion 23.

  As described above, in the boot band of the present invention, since a gap is not easily formed between the inner surface 30 of the lever 26 and the outer diameter surface 23a of the ring portion 23, a stable assembled state of the band 1 can be maintained and a sealing property can be maintained. The constant velocity universal joint boot 3 can be stably fixed over a long period of time.

  In the embodiment, since the chamfer 29 is provided, it is possible to prevent stress concentration at the corners of the band body 24 and to attach the band mounting portion (large diameter portion) of the constant velocity universal joint boot 3 fastened by the band 1. 3a and the small diameter portion 3b), the corner portion of the band main body 24 does not bite, and the constant velocity universal joint boot 3 and the band main body 24 can be effectively prevented from being damaged.

  By the way, in the said embodiment, as shown in FIG. 2, when the lever 26 is overlapped with the band main body 24, the clearance gap S arises in the edge part by the side of a lever return. Therefore, in FIG. 5, the band main body 24 is provided with a protrusion 40 that fills the gap S on the end portion side on the lever folding side. The protrusion 40 can be configured, for example, by providing a U-shaped notch in a part of the band main body 24 and bulging the remaining portion inside the notch toward the inner diameter side. Further, another member constituting the protrusion 40 may be joined to the band body 24 by welding or the like. In short, the inner surface of the protrusion 40 may be an arcuate surface corresponding to the outer diameter surface of the large diameter portion 3a or the small diameter portion 3b of the boot 3 in a state where the diameter of the ring portion 23 of the band main body 24 is reduced. Here, filling the gap S does not need to completely eliminate the gap, and may be slightly left as shown in FIG. Of course, the gap may be completely eliminated.

  Thus, by providing the protrusion 40, the band mounting portion (the large diameter portion 3a and the small diameter portion 3b) of the boot 3 can be tightened with a substantially uniform tightening force over the entire circumference in the circumferential direction. Thereby, further improvement in assembling property and sealing property can be achieved.

  By the way, the constant velocity universal joint is not limited to a barfield type fixed constant velocity universal joint as shown in FIG. 3, and may be an undercut free type fixed constant velocity universal joint. Various types of sliding constant velocity universal joints such as tripod type and cross groove type may be used.

  The Barfield type fixed constant velocity universal joint includes an outer joint member in which a plurality of track grooves are formed on the inner diameter surface along the axial direction at equal intervals in the circumferential direction, and a track groove of the outer joint member on the outer diameter surface. A ball in which a plurality of paired track grooves are formed along the axial direction at equal intervals in the circumferential direction, and the track groove of the outer joint member and the track groove of the inner joint member are formed in cooperation. A torque transmission ball disposed on each track and a cage for holding the ball are provided.

  Undercut-free fixed constant velocity universal joints are different from barfield fixed fixed constant velocity universal joints where the track groove bottom is only an arc portion, while the track groove bottom is formed from an arc portion and a straight portion. It will be.

  The double offset type constant velocity universal joint includes an outer joint member having a track groove formed on the inner peripheral surface, an inner joint member having a track groove formed on the outer peripheral surface, and the track groove and the inner joint member of the outer joint member. And a cage having a pocket for accommodating the ball, and the center of the outer peripheral surface of the cage and the center of the inner peripheral surface are relative to the joint center. It is offset in the opposite direction to the axial direction.

  The tripod type constant velocity universal joint includes an outer joint member in which three track grooves having roller guide surfaces arranged in the circumferential direction are formed in the axial direction, and three leg shafts projecting in the radial direction. A tripod member and a roller member fitted on the leg shaft.

  The cross groove type constant velocity universal joint has an inner joint member having an outer peripheral surface in which ball grooves inclined in opposite directions with respect to the axis are alternately formed in the circumferential direction, and inclined in directions opposite to each other with respect to the axis. An outer joint member having an inner peripheral surface in which track grooves are alternately formed in the circumferential direction, a torque transmission ball incorporated at the intersection of the track groove of the inner joint member and the track groove of the outer ring, and the torque transmission ball are held It is equipped with a cage.

  As described above, the embodiment of the present invention has been described. However, the present invention is not limited to the above-described embodiment, and various modifications are possible. For example, the radial dimension of the inner surface 30 that is the concave curved surface of the lever 26 and the ring portion The difference between the outer diameter and the outer diameter of the ring portion 23 can be variously changed based on the outer diameter of the outer diameter of the lever 26 and the outer diameter surface of the ring portion 23. The difference must be such that no gap is formed between them. Moreover, even if it is the magnitude | size of the round chamfer 29a as shown to Fig.4 (a) and the square chamfer 29B as shown to FIG.4 (B), the large diameter part 3a and the small diameter part 3b of the boot 3 which are to-be-clamped members are used. Various changes can be made within a range that does not cause damage. Further, the width and thickness of the band-shaped member constituting the band main body 24 can be variously changed according to the outer diameter of the large-diameter portion 3a and the small-diameter portion 3b of the boot 3 which is a member to be tightened.

2 Constant Velocity Universal Joint 3 Constant Velocity Universal Joint Boots 21 and 22 End 23 Ring Portion 23a Outer Diameter Surface 24 Band Main Body 25 Joint 26 Lever 30 Inner Surface 40 Protrusion S Clearance

Claims (10)

A band main body formed at the ring portion by joining the end portions and an arc-shaped lever attached to the outer diameter surface of the joint portion of the band main body. A boot that tightens the band mounting portion of the boot for a constant velocity universal joint that is externally fitted in the ring portion by reducing the diameter of the ring portion of the band body by being folded back so as to overlap the outer diameter surface of the main body. A band,
A boot band characterized in that a diameter of an inner surface which is a concave curved surface of a lever is made larger than a diameter of an outer diameter when the ring portion is contracted.   The boot band according to claim 1, wherein the band main body is provided with a protrusion that fills a gap at an end portion on the lever folding side that is generated when the lever is superimposed on the band main body.   The boot band according to claim 1 or 2, wherein the band body is a rectangular section having rounded chamfers at four corners.   The boot band according to claim 1 or 2, wherein the band main body is a rectangular section having four corners chamfered.   The boot band according to any one of claims 1 to 4, wherein the constant velocity universal joint boot is a rubber boot.   The boot band according to claim 5, wherein the rubber boot is chloroprene rubber or silicon rubber.   The boot band according to claim 5 or 4, wherein the rubber boot has a surface hardness of Hs50 to Hs70.   The boot band according to any one of claims 1 to 4, wherein the constant velocity universal joint boot is a resin boot.   The boot band according to claim 8, wherein the resin boot is a thermoplastic polyester elastomer or a composition containing a thermoplastic polyester elastomer.   The boot band according to claim 8 or 9, wherein the surface hardness of the resin boots is HDD38 to HDD50.

Images