JP5363855B2 - Flexible boots for plastic constant velocity joints - Google Patents

Description

  The present invention relates to a flexible boot that is attached to a constant velocity joint and used for grease retention and dust prevention (in the present specification, such a flexible boot is generically referred to as a CVJ boot). More specifically, the present invention relates to a bellows structure that enables a high operating angle of a resin-made CVJ boot.

  In recent years, CVJ boots are mainly made of resin in order to sufficiently satisfy the requirements for ozone resistance and wear resistance. Since this resin-made CVJ boot is less flexible than a rubber-made boot, it is devised to adopt a structure that is easily deformed by increasing the number of bellows. Nevertheless, in the resin-made CVJ boot, a portion where the compressive force (stress) applied between the bellows and the connecting portion when a high operating angle is taken tends to occur, and the necessary fatigue resistance against repeated bending is obtained. There is a problem that cannot be obtained.

  For example, in a plastic joint boot, when the constant velocity joint operating angle increases, the bending torque when the bellows is bent tends to increase following this inclination. Since this bending torque acts as a force in the direction of peeling off the fixed portions at both ends from the inside of the boot, there is a possibility that the sealing performance is impaired and grease leakage occurs.

  Therefore, as shown in FIG. 8, a sealing protrusion 102 is formed on the inner peripheral surface side in the large-diameter end short cylindrical portion (large-diameter mounting portion) 101 and the small-diameter end short cylindrical portion (small-diameter mounting portion; not shown). In addition, a groove 103 having a width dimension in the opening equal to or larger than a depth dimension is provided on the outer peripheral surface side of the central portion of the width of the seal protrusion 102 in the joint boot axial direction. Conventionally, a resin-made CVJ boot corresponding to a high operating angle in which sufficient sealing performance can be obtained without increasing the tightening force of the tightening band has been proposed (Patent Document 1). In the figure, reference numeral 104 denotes an outer ring of a constant velocity joint, 105 denotes a bellows portion of the boot, 106 denotes a cylindrical connecting portion connecting the bellows portion and the large-diameter end short cylindrical portion, and 109 denotes a valley portion.

  Further, as disclosed in Patent Document 1, in the resin joint boot, the large-diameter mounting portion 101 is fixed by the fastening band 108 on the back side from the end edge of the outer ring (outer case) 104 of the constant velocity joint. Therefore, it is common to include a cylindrical connecting portion 106 that connects the large-diameter mounting portion 101 and the bellows portion 105. In the joint boot having the cylindrical connecting portion 106, the valley portion 109 on the side of the largest diameter attachment portion of the bellows portion 105 contacts the tip surface 110 of the outer ring 104 when the joint boot is rotated with a large operating angle. As a result, the valley portion 109 of the bellows portion 104 adjacent to the large-diameter mounting portion 101 has a problem that durability is inferior. That is, as shown in FIG. 9 and FIG. 10, the first trough portion on the large-diameter mounting portion side of the bellows portion 105 is pressed against the tip surface 110 of the outer ring 104 by the second and subsequent trough portions on the bent inner side. This is considered to be caused by the deformation. In the figure, reference numeral 107 denotes a constant velocity joint shaft, and 111 denotes a small diameter mounting portion.

  Therefore, as shown in FIG. 11, the large-diameter mounting portion 201 is connected to the bellows portion 202 via a cylindrical connecting portion 203 that surrounds the outer periphery of the distal end portion of the outer ring 205, and the cylindrical connecting portion 203 is centered in the axial direction. There has been proposed a CVJ boot formed in a constricted shape recessed radially inward at the portion (Patent Document 2). That is, a CVJ boot having a structure in which the valley 204 of the bellows portion 202 is deformed so as to open the space S so as not to contact the end face of the outer ring 205 has been proposed. In this way, by forming the cylindrical connecting portion 203 into a constricted cylindrical shape, the valley portion on the large-diameter mounting portion 201 side of the bellows portion 204 by appropriately bending the cylindrical connecting portion 203 when the operating angle is high. It is possible to avoid the contact of 204 with the front end surface of the outer ring 205, and the durability can be improved. Reference numeral 206 in the figure denotes a bush.

JP2002-228016 JP2007-120580A

  However, as shown in FIG. 12, in the resin-made CVJ boot, the folding interval L1 on the boot compression side is determined by the dimensions of the outer ring and the shaft and the maximum operating angle. When the operating angle becomes high, the convolution interval L1 becomes smaller. On the other hand, when the angle is high, the development interval L2 on the boot extension side becomes larger. Therefore, if the film length is insufficient, the boot will naturally dent and the boot will not function. Can not be reduced. Therefore, in the resin-made CVJ boot structure of Patent Document 1, as shown in FIG. 10, the bellows 105 comes into contact with the outer ring 104 when the high operating angle is applied, and the bellows 105 is located between the outer ring 104 and the shaft 107. The contact pressure between the bellows 105 is increased and the wear is caused.

  In addition, the bellows valley portion is bitten into the joint and is damaged, or the connecting portion is compressed to deform the band fixing portion to contact the band fixing portion rising surface and the band or the band edge on the bottom surface of the band fixing portion. There is a risk of bending parts.

  On the other hand, by forming the cylindrical connecting portion 203 into a constricted cylindrical shape, the trough portion 204 on the large-diameter mounting portion side of the bellows portion 202 can be formed by appropriately bending the cylindrical connecting portion 203 when the operating angle is set high. Even in the CVJ boot of Patent Document 2 that avoids contact with the front end surface of the outer ring 205, that is, a CVJ boot that is deformed so that the valley portion of the bellows portion does not contact the end surface of the outer ring, the folding interval L1 on the boot compression side is Since it is uniquely determined by the dimensions of the outer ring and the shaft and the maximum operating angle, a space S is provided as shown in FIG. 11 so that the valley portion 204 on the large-diameter mounting portion side of the bellows portion 202 contacts the tip surface of the outer ring 205. By deforming to avoid this, the contact pressure between the bellows 202 becomes higher, causing a problem of wear and lowering the durability.

  Accordingly, the present invention not only reduces the contact surface pressure between the bellows and the outer ring end surface at a high operating angle, but also reduces the contact surface pressure between the bellows to suppress the occurrence of wear on the bellows portion, thereby reducing durability. It is an object of the present invention to provide a resin-made CVJ boot that can prevent the valley portion of the bellows from being bitten into the joint and being damaged. Another object of the present invention is to provide a resin-made CVJ boot that prevents cracks and wear around the band fixing portion of the large-diameter mounting portion at a high operating angle.

In order to achieve such an object, the invention described in claim 1 includes a large-diameter mounting portion fixed to the outer ring outer peripheral surface of the constant velocity joint, a small-diameter mounting portion fixed to the shaft of the constant velocity joint, and both the mounting portions. In the flexible boot for a constant velocity joint made of resin comprising a bellows portion that gradually decreases the diameter of the valley and valley in a conical shape or a shell shape formed between, and a connecting portion that connects the large diameter mounting portion and the bellows portion, the connecting portion is It is possible to bend toward the outer side of the outer ring of the constant velocity joint, and the inner diameter G of 2 to 4 valleys adjacent to or near the connecting portion of the bellows part and the outer ring outer diameter F of the constant velocity joint are G> 0.7F. of the relationship, so that two to four valleys of adjacent or nearby rides the connecting portion on the outer peripheral surface during compression of the bellows portion at the time of high operating angle.

The invention according to claim 2 is the flexible boot for a plastic constant velocity joint according to claim 1, wherein the connecting portion has an arc shape protruding inward toward the outer ring of the constant velocity joint, It can be bent so as to warp toward the outside of the outer ring of the constant velocity joint when receiving a compressive force.

According to a third aspect of the present invention, in the flexible boot for a resin constant velocity joint according to the first or second aspect, the inner diameter of the trough that rides on the outer peripheral surface of the outer ring when the bellows portion is compressed is the end surface of the outer ring of the constant velocity joint The relationship is larger than the inner diameter at.

Furthermore, the invention described in claim 4 is the flexible boot for a constant velocity joint made of resin according to any one of claims 1 to 3 , wherein the inner diameter E of the connecting portion and the outer diameter F of the outer ring are F−. The relationship is 10 mm ≦ E ≦ F + 2 mm.

  According to the resin-made CVJ boot according to claim 1, since at least one valley portion adjacent to or near the connecting portion rides on the outer ring outer peripheral surface on the compression side of the bellows portion at a high operating angle, The amount of bellows sandwiched between the outer ring and the shaft is reduced by that amount, not only reducing the contact surface pressure between the bellows and the outer ring end surface, but also reducing the contact surface pressure between the bellows to reduce the wear of the bellows part. It can be suppressed to prevent a decrease in durability. In addition, the difference between the distance between the expansion side (opening side) of the bellows at the high operating angle and the distance between the compression side (folding side) becomes small, and the deflection of the boot becomes gentle, so that the rotation becomes smooth. Furthermore, since at least one valley of the bellows rides on the outer ring outer peripheral surface at a high operating angle, the bellows of the bellows adjacent to the bellows bends away from the shaft so that the valley is caught in the joint. The risk of being lost is reduced.

In addition, connecting portions at the time of high operating angle can axial space on the outer ring outer circumferential surface by bending toward the outside of the outer ring of the constant velocity joint, valleys are easily rides on the outer ring outer circumferential surface. This increases the number of valleys near the large-diameter mounting portion that rides on the outer ring, further reduces the amount of bellows sandwiched between the outer ring and the shaft, and further reduces the contact surface pressure between the bellows and the outer ring end face, The contact surface pressure between the bellows can be further reduced to suppress the occurrence of wear at the bellows portion, thereby preventing the durability from being lowered.

Further, according to the resin-made CVJ boot according to claim 2 , when the constant velocity joint takes a high operating angle and receives a compressive force from the bellows portion, the connecting portion warps toward the outside of the outer ring of the constant velocity joint. Therefore, smoother deformation of the connecting portion and the bellows on the compression side can be expected. Therefore, when the constant velocity joint has a high operating angle, an axial space is created on the outer peripheral surface of the outer ring, and a trough adjacent to the connecting portion moves radially outward, and the trough rises further on the outer peripheral surface of the outer ring. It becomes easy. This increases the number of valleys near the large-diameter mounting portion that rides on the outer ring, further reduces the amount of bellows sandwiched between the outer ring and the shaft, and further reduces the contact surface pressure between the bellows and the outer ring end face, The contact surface pressure between the bellows can be further reduced to suppress the occurrence of wear at the bellows portion, thereby preventing the durability from being lowered.

Furthermore, according to the resin-made CVJ boot according to claim 3, since the inner diameter of the valley portion riding on the outer peripheral surface of the outer ring is larger than the inner diameter of the end surface of the outer ring of the constant velocity joint, even if the valley portion contacts the outer ring end surface. The trough is not bitten into the joint, and the trough easily climbs on the outer peripheral surface of the outer ring.

Further, according to the resin-made CVJ boot according to claim 4, since the inner diameter E of the bending point of the connecting portion and the outer diameter F of the outer ring are in a relationship of F-10 mm ≦ E ≦ F + 2 mm, the connecting portion is tight to the outer ring. It does not become difficult to tighten and fit, and at high operating angles (when boots are compressed), the movement of the connecting part in the axial and radial directions is moderately restricted to prevent excessive movement. It is possible to reduce the burden on the diameter mounting portion and the lifting of the large diameter mounting portion, and prevent damage and deterioration of the sealing performance.

It is a center longitudinal section showing one embodiment of a resin-made CVJ boot concerning the present invention, and shows a state of an operating angle of 0 degrees in a state where it is mounted on a constant velocity joint. It is a center longitudinal cross-sectional view which shows the state at the time of the high operating angle of the resin-made CVJ boot. It is the figure which expands and shows the relationship between a large diameter attaching part and a bellows part adjacent to a connection part, and shows what changed the form of the connection part to (A)-(D). It is explanatory drawing which shows the relationship between the outer diameter of the outer peripheral surface of the outer ring | wheel in embodiment of the CVJ boot shown in FIG. 1, and the internal diameter in the bending point of a connection part, and the internal diameter of the trough part adjacent to a connection part. It is explanatory drawing which shows the relationship between the boot on the compression side at the time of a high working angle, and an outer ring | wheel in embodiment of the CVJ boot shown in FIG. It is a center longitudinal cross-sectional view which shows other embodiment of the resin-made CVJ boots concerning this invention, and shows the state of the operating angle of 0 degree in the state with which the constant velocity joint was mounted | worn. It is a center longitudinal cross-sectional view which shows the state at the time of the high working angle of the resin-made CVJ boots of FIG. It is explanatory drawing which shows the relationship between the large diameter attachment part of a conventional resin-made CVJ boot, a connection part, a bellows part, and an outer ring | wheel. It is a central longitudinal cross-sectional view which similarly shows the shape change state of the connection part and bellows part with respect to the outer ring | wheel at the time of the high operating angle of the conventional resin CVJ boot. It is explanatory drawing which expands and shows the shape change state of the connection part with respect to an outer ring | wheel, and a bellows part in the resin-made CVJ boots of FIG. It is explanatory drawing which shows the relationship between the large diameter attaching part of other conventional resin-made CVJ boots, a connection part, a bellows part, and an outer ring in the state which gave the operating angle. It is explanatory drawing which shows the relationship of the boot length of the compression side of a CVJ boot when an operating angle is given to a constant velocity joint, and the expansion | extension side.

  Hereinafter, the configuration of the present invention will be described in detail based on embodiments shown in the drawings.

  1 and 2 show an embodiment of the resin-made CVJ boot of the present invention. The CVJ boot 1 includes a bellows portion 3 and a large-diameter attachment portion 4 and a small-diameter attachment portion 5 for attaching both ends of the bellows portion 3 to the outer ring 7 and the shaft 8 of the constant velocity joint 2, respectively. A connecting portion 6 that connects the bellows portion 3 is provided, and the large-diameter mounting portion 4 is fitted to the outer ring 7 and the small-diameter mounting portion 5 is fitted to the shaft 8 so that the fastening bands 9 and 10 are respectively connected. It is attached to the constant velocity joint 2 by being fixed by tightening.

The CVJ boot 1 has two to four inner diameters G of the valley portions 11 adjacent to the connecting portion 6 of the bellows portion 3 as the outer ring outer diameter F of the constant velocity joint 2 and the inner diameters of the other valley portions 12. H is made smaller than the outer ring outer diameter F, and at least one of the valley parts 11 adjacent to the connecting part 6 is provided on the outer ring outer peripheral surface 7b when the bellows part 3 is compressed at a high operating angle. . Here, if the valley portion 11 adjacent to the connecting portion 6 of the bellows portion 3 exists so as to touch the outer peripheral surface 7b of the outer ring 7 in a state where the operating angle of the constant velocity joint is 0 or small, the constant velocity joint 2 has a high operating angle. On the extension side, the trough 11 on the outer ring is in sliding contact with the outer circumferential surface 7b of the outer ring. On the other hand, if the inner diameter of the valley portion 11 is excessively increased in order to prevent the valley portion 11 of the boot on the extended side at the high operating angle from slidingly contacting the outer peripheral surface 7b of the outer ring, There is a risk that the boot will dent when stretched due to the shortened membrane length. Therefore, when the operating angle of the constant velocity joint 2 is 0 or small, the valley portion 11 adjacent to the connecting portion 6 of the bellows portion 3 does not exist on the outer ring outer peripheral surface 7b and is attached with a smaller diameter than the outer ring outer peripheral surface 7b. It is preferable that it is located on the part 5 side. In the present embodiment, the outer ring outer peripheral surface 7b is a chamfered portion except for the chamfered portion 7c formed between the outer ring outer peripheral surface 7b and the end surface 7a as shown in FIGS. The inner side in the axial direction from 7c (the side opposite to the end surface 7a indicated by the arrow I) is referred to as an outer ring outer peripheral surface 7b. Further, the position indicated by the symbol J is the position of the inner diameter of the outer ring on the end surface 7a of the outer ring.

  Here, the valley portion 11 having an inner diameter G that is substantially the same as the outer ring outer diameter F of the constant velocity joint 2 is such that at least one valley 11 rides on the outer ring 7 on the outer ring 7 in a state where a high operating angle is taken. Since the amount of the bellows 3 sandwiched between the outer ring 7 and the shaft 8 can be reduced by that amount, at least one of the valley portions 11 adjacent to the connecting portion 6 that is closest to the connecting portion is also effective. On the other hand, if the number of the valley portions 11 having the same inner diameter G as the outer ring outer diameter F of the constant velocity joint 2 is excessively increased, the film length of the entire bellows becomes insufficient when the bellows portions 3 having the same number of peaks and valleys are formed. Thus, there is a possibility that the natural depression of the boot occurs and the boot does not function. Therefore, at least one, preferably two or three valleys 11 having an inner diameter G substantially the same as the outer ring outer diameter F of the constant velocity joint 2 are provided. Then, the inner diameter H of the other trough 12 is sufficiently smaller than the outer diameter F of the outer ring as shown in FIG.

  The connecting portion 6 may have a cylindrical shape as shown in Patent Document 1, but preferably has a shape that can be bent toward the outer side of the outer ring 7 of the constant velocity joint 2. According to this outwardly bendable structure, when the constant velocity joint 2 takes a high operating angle, the connecting portion 6 that receives the compression force bends toward the outside of the outer ring 7 of the constant velocity joint 2, so that the outer peripheral surface of the outer ring A space in the axial direction is formed on 7b, and the valley portion 11 can easily ride on the outer peripheral surface 7b of the outer ring. In particular, as in the first embodiment shown in FIGS. 1, 2, and 3 (A), it has an arc shape protruding inward toward the outer ring 7 of the constant velocity joint 2, and from the bellows portion 3. In the case of a shape that can be bent so as to warp toward the outside of the outer ring 7 of the constant velocity joint 2 when receiving the compressive force of the constant velocity joint 2, Warping outward in the radial direction creates an axial space on the outer peripheral surface of the outer ring and warping the connecting portion radially outward causes the adjacent valley portion 11 to be displaced radially outward from the outer ring. It becomes easier for the trough 11 to ride on 7b. Also, as shown in FIG. 3B, the conical surface shape gradually decreases in diameter from the large diameter attaching portion 4 toward the bellows portion 3 side, or as shown in FIG. 3C, the large diameter attaching portion. 4 is formed in a cylindrical shape in which a bent portion formed by a concave portion that is recessed outward (toward the outer diameter side) is provided, or from the large diameter mounting portion 4 to the bellows portion 3 side as shown in FIG. It is also possible to have a conical surface shape with a gradually increasing diameter. 6 and 7 show an embodiment of a resin CVJ boot to which the connecting portion shown in FIG. 3D is applied.

  In addition, since the resin CVJ boot 1 is made of resin and is hard, it is extremely difficult to incorporate the resin CVJ boot 1. Therefore, considering the fitting performance to the joint 2, the bending point located on the outer ring 7 of the constant velocity joint 2. It is not preferable that the inner diameter dimension E of X is made much smaller than the outer ring outer diameter dimension F. According to the experiments by the present inventors, it is considered not preferable that φE <φF−10 mm. On the other hand, if the inner diameter dimension E of the bending point X is φE-2> φF, the gap between the bending point X and the outer ring 7 becomes large when the boot is compressed, so that the degree of freedom of the connecting portion 6 becomes too high and is connected when compressed. Since the portion 6 is deformed so as to move excessively toward the large-diameter attachment portion 4 and lift the large-diameter attachment portion 4, stress is applied to the contact portion 6 a that contacts the edge 10 a of the fastening band 10 of the large-diameter attachment portion 4 and the vicinity thereof. This is considered to cause a large load on the large-diameter mounting portion 4 and cause damage and a decrease in sealing performance (see FIG. 5). Therefore, it is preferable to set the inner diameter E of the bending point X of the connecting portion 6 and the outer diameter F of the outer ring 7 to have a relationship of F−10 mm ≦ E ≦ F + 2 mm.

  According to the resin-made CVJ boot configured as described above, when the number of peaks and valleys is the same, when at least one valley near the large-diameter mounting portion of the bellows portion 3 runs on the outer peripheral surface of the outer ring 7, FIG. As shown, the convolution interval L1 on the compression side decreases. That is, the number of bellows sandwiched between the outer ring end surface 7a and the shaft (small diameter side attachment portion 5) is reduced, so that not only the contact surface pressure between the bellows and the outer ring end surface is reduced, but the bellows It is possible to reduce the contact surface pressure and suppress the occurrence of wear on the bellows portion, thereby preventing a decrease in durability. Further, since the convolution interval L1 on the compression side is reduced, a higher operating angle can be obtained with the same contact surface pressure. Further, the difference between the development interval L2 on the boot extension side and the convolution interval L1 on the boot compression side becomes small, the deflection of the boot becomes gentle, and the rotation becomes smooth. The same applies to the resin-made CVJ boot to which the connecting portion 6 having a different form illustrated in FIGS. 6 and 7 is applied.

A resin-made CVJ boot having the shape shown in FIG. 1 was produced, and a test was performed on the occurrence of riding on the outer ring of the bellows on the compression side when the constant velocity joint has a high operating angle. The results are shown in Table 1. The boot used in this test is made of polyester elastomer, and has a large-diameter mounting portion inner diameter of 74 mm, a small-diameter mounting portion inner diameter of 22 mm, and a bellows portion adjacent to the connecting portion. The outer diameter of the outer ring of the constant velocity joint is 76 mm. The operating angle θ of the constant velocity joint is 48 °.

  From this test result, if the inner diameter G of the valley portion 11 is 70% or more of the outer ring outer diameter F, the valley portion 11 does not run on the outer peripheral surface of the outer ring at the high operating angle and does not remain on the end surface of the outer ring. It was found that when it was less than 60%, it could not ride on the outer peripheral surface of the outer ring and remained at the end of the outer ring. Therefore, the inner diameter G of the valley portion 11 needs to be 70% or more of the outer ring outer diameter F. On the other hand, the upper limit of the valley diameter G needs to be smaller than the inner diameter of the adjacent peaks so that the bellows shape can be maintained.

Next, a confirmation test was conducted on the durability according to the inner diameter of the bending point of the connecting portion of the boot. The test confirmed the state of breakage of the boot when rotated at 400 rpm for 50 hours in an atmosphere of 120 ° C. with the operating angle θ of the constant velocity joint set to 48 °. The results are shown in Table 2.

  From this test result, it was found that when the inner diameter dimension E of the bending point of the connecting portion connecting portion was within a range of ± 2 mm with respect to the outer ring outer diameter F, no fracture occurred under the same test conditions.

  The above-described embodiment is an example of a preferred embodiment of the present invention, but is not limited thereto, and various modifications can be made without departing from the gist of the present invention. For example, although not shown in the figure, the connecting portion 6 is made thinner than the other portions so that it can be easily bent outward, or by giving fine bellows-like irregularities to increase flexibility. Also good.

DESCRIPTION OF SYMBOLS 1 Resin CVJ boot 2 Constant velocity joint 3 Bellows part 4 Large diameter attachment part 5 Small diameter attachment part 6 Connection part which connects large diameter attachment part and bellows part 7 Outer ring of constant velocity joint 7a End surface of outer ring 7b Outer surface of outer ring 7c Chamfer 8 Constant velocity joint shaft 9, 10 Tightening band 11 Valley adjacent to the connection 12 Other valley (valley other than the valley adjacent to the connection)
E Inner diameter of the bent portion of the connecting portion F Outer diameter of the outer peripheral surface of the outer ring G Inner diameter of the valley portion adjacent to the connecting portion H Inner diameter of the valley portion other than the valley portion adjacent to the connecting portion I The outer peripheral surface of the outer ring and the chamfered portion Boundary position J Inner diameter position on outer ring end face X Bending point

Claims (4)

A large-diameter mounting part fixed to the outer ring outer peripheral surface of the constant velocity joint, a small-diameter mounting part fixed to the shaft of the constant velocity joint, and a conical shape or a bullet shape formed between these two mounting parts, In a flexible boot for a plastic constant velocity joint comprising a bellows portion that gradually decreases and a connecting portion that connects the large-diameter mounting portion and the bellows portion, the connecting portion bends toward the outside of the outer ring of the constant velocity joint. A high operating angle is set such that the inner diameter G of the two to four valleys adjacent to or near the connecting portion of the bellows portion and the outer ring outer diameter F of the constant velocity joint satisfy G> 0.7F. A flexible boot for a constant velocity joint made of resin, on which 2 to 4 troughs adjacent to or near the connecting portion ride on the outer peripheral surface of the outer ring when the bellows portion is compressed. The connecting portion has an arc shape protruding inward toward the outer ring of the constant velocity joint, and is bent so as to warp toward the outside of the outer ring of the constant velocity joint when receiving a compressive force from the bellows portion. The flexible boot for resin-made constant velocity joints of Claim 1 which is possible . 3. The flexible boot for a resin constant velocity joint according to claim 1, wherein an inner diameter of the valley portion that rides on an outer peripheral surface of the outer ring when the bellows portion is compressed is larger than an inner diameter of an end surface of the outer ring of the constant velocity joint. . The flexible boot for a resin constant velocity joint according to any one of claims 1 to 3, wherein an inner diameter E of the bending point of the connecting portion and an outer diameter F of the outer ring are in a relationship of F-10mm≤E≤F + 2mm. .

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