JP2009293797A - Boot for constant velocity joint - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a boot for a constant velocity joint with superior durability. <P>SOLUTION: In the boot for a constant velocity joint, a small diameter cylindrical part 12 and a large diameter cylindrical part 11 provided on both ends of a bellows-like body part 10 are respectively fixed by a shaft and a housing with fastening bands. A collar part 11b extending like a flange in the outer diameter direction is provided on an end in an opposite side of a body part 10 side in the large diameter cylindrical part 11, a collar part 13 abutting on the collar part 11b of the large diameter cylindrical part 11 is provided on a cylindrical mounting member 13 having a protruding thick part 13a along an outline of the housing and interposed between the large diameter cylindrical part 11 and the housing, and abutting faces of the collar part 11b of the large diameter cylindrical part 11 on the collar part 13b of the cylindrical mounting member 13 are welded. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a constant velocity joint boot.

  Conventionally, as a constant velocity joint boot for protecting a movable mechanism portion of a constant velocity joint (constant velocity universal joint) in an automobile or industrial machine, there is one as shown in FIG. 18A and 18B are schematic views for explaining the configuration of a constant velocity joint boot according to the prior art. FIG. 18A is a sectional view of the constant velocity joint boot, and FIG. FIG.

  As shown in FIG. 18A, a constant velocity joint boot 100 includes a cylindrical body portion 101 having a bellows shape that can be expanded and contracted and deformed, and a small-diameter tube formed at one end of the body portion 101 in the axial direction. And a large-diameter cylindrical portion 103 formed at the other end in the axial direction. The small-diameter cylindrical portion 102 is attached to one of an input shaft and an output shaft that can change the crossing angle with each other, and the large-diameter cylindrical portion 103 is a housing that houses the other shaft and bearing components. It is attached to (outer race).

  As shown in FIG. 18B, the inside of the large-diameter cylindrical portion 103 is provided between the three convex thick portions 103a and each thick portion 103a so as to follow the outer shape of the housing (not shown). It is comprised by the tripod shape which has the three thin part 103b formed.

  As a material for tripod type constant velocity joint boots, rubber materials such as chloroprene rubber are mainly used because it is difficult to mold with TPE (thermoplastic elastomer) material. Therefore, there is an increasing demand for TPE, which is the same material as conventional circular type constant velocity joint boots.

  Boots using TPE material are generally made by blow molding, but in the case of tripod type, the outer race has a non-circular shape with a plurality of recesses on the circumference. Since there is a thick part for fitting, it is difficult to manufacture by conventional blow molding.

  On the other hand, a method for creating portions having different thicknesses using an injection blow method has been proposed. However, in the injection blow method, the structure of the mold and the molding machine is complicated, and enormous time and labor are required to obtain an appropriate film thickness of the bellows part.

  In addition, in order to obtain an appropriate thickness of the bellows part, the bellows part is formed by conventional blow molding, and the tripod part is molded by injection while holding the bellows part in the blow mold (two-color molding) ) Has also been proposed. However, this method also requires a very complicated configuration of the molding machine and low versatility and productivity, which requires much time and labor in production.

Patent Document 1 discloses a method in which a grommet is formed separately by injection molding, the bellows part is formed by conventional blow molding, and then the grommet and bellows part are joined by laser welding. However, in this method, the outer peripheral surface of the grommet and the inner peripheral surface of the bellows portion large-diameter cylindrical portion are welded. In the method of welding between the cylindrical surfaces, the welding surface is sufficiently welded at the time of welding. It is difficult to obtain a complete all-around weld. In addition, since the small-diameter cylindrical portion and the large-diameter cylindrical portion at both ends of the boot are fixed to the shaft and the outer race by metal fastening bands, stress due to deformation such as expansion and contraction of the boot is affected by the grommet and the large-diameter cylindrical portion. It acts directly on the welded portion, and is easy to crack in the welded portion.
JP 2005-036961 A

  The present invention has been made to solve the above-described problems of the prior art, and an object of the present invention is to provide a constant velocity joint boot excellent in durability.

In order to achieve the above object, the constant velocity joint boot in the present invention,
A cylindrical body having a flexible bellows shape;
A small-diameter cylindrical portion attached to one of the two shafts provided at one end of the body portion and capable of changing the crossing angle with each other;
A boot body having a large-diameter tubular portion provided at the other end of the body portion and attached to a housing that accommodates the other of the two shafts;
A cylindrical mounting member that is interposed between the inner peripheral surface of the large-diameter cylindrical portion and the outer peripheral surface of the housing and has a convex thick portion that protrudes in the inner diameter direction along the outer shape of the housing. And comprising
In the constant velocity joint boot fixed to the one shaft and the housing by a fastening band attached to the outer peripheral surface of the small diameter cylindrical portion and the large diameter cylindrical portion,
A flange portion extending in a flange shape in the outer diameter direction is provided at an end of the large-diameter cylindrical portion opposite to the body portion side,
The tubular mounting member is provided with a flange portion that comes into contact with the flange portion of the large-diameter tubular portion,
The contact surface of the collar part of the said large diameter cylindrical part and the collar part of the said cylindrical attachment member was welded.

  Thus, since the welding part is provided outside the fastening band fixing part, the stress due to the expansion and contraction of the boot does not directly act on the welding part. Therefore, generation | occurrence | production of the crack of a weld part, etc. is suppressed, and lifetime improvement of a boot can be achieved.

  In addition, it has a configuration in which the flat surfaces of the flange portions provided on the large-diameter cylindrical portion and the cylindrical mounting member are welded to each other, and the entire welding surface is easily pressed uniformly. Compared to the above, a more complete contact state can be formed. Therefore, it is possible to improve the integrity of the large-diameter cylindrical portion (boot main body) and the cylindrical mounting member.

While chamfering the inner diameter side corner of the end surface of the tubular mounting member opposite to the inner side of the body portion,
It is good to provide the cavity part opened in the end surface of the inner side of the said trunk | drum part in the said cylindrical attachment member in the said convex thick part.

  Thus, by providing a hollow part in a convex thick part, generation | occurrence | production of the sink in a convex thick part thicker than another site | part can be suppressed, and a dimensional accuracy can be improved.

  Further, by providing the cavity portion so as to open at the end surface opposite to the end surface where chamfering is formed, a cavity portion having a shape corresponding to the chamfered shape can be formed. Therefore, a more uniform wall thickness can be obtained.

  Further, since the hollow portion is not exposed to the outside of the boot, it is possible to prevent the occurrence of foreign matter biting into the hollow portion, rainwater accumulation, and the like, and to suppress the occurrence of cracks and corrosion.

  A small-diameter portion that extends in a flange shape in the inner diameter direction and abuts against the shoulder portion of the housing may be provided at an end portion on the inner side of the body portion of the cylindrical mounting member.

  Since the small-diameter portion abuts against the shoulder portion of the housing, it is accurately positioned with respect to the housing, so that positioning at the time of assembly is facilitated, and assemblability is improved. Further, since positioning is performed accurately, there is no difference in position for each joint, and a stable life can be obtained.

  In addition, the load generated when the boot is contracted is received by the cylindrical mounting member by the small diameter portion contacting the shoulder of the housing, so the load on the tightening band and the boot body is reduced, Generation | occurrence | production of the position shift of boots can be suppressed.

  An uneven fitting portion may be provided between the outer peripheral surface of the cylindrical mounting member and the inner peripheral surface of the large-diameter cylindrical portion.

  Thereby, the shift | offset | difference of the contact part of a large diameter cylindrical part and a cylindrical attachment member is suppressed.

  It is good to provide the recessed part for releasing the burr | flash formed in the collar part of the said large diameter cylindrical part in the collar part of the said cylindrical attachment member.

  Thereby, it becomes possible to form more reliably the welding state of the planes of the collar part of a large diameter cylindrical part and the collar part of a cylindrical attachment member.

  In addition, since the allowable size of the burr is increased, it is possible to reduce the number of manufacturing steps by eliminating the work for deleting the burr.

  In addition, in the welding surface between the flange portion of the large-diameter cylindrical portion and the flange portion of the cylindrical mounting member, a part of the molten resin that has conventionally flowed out to the outer peripheral surface of the welding portion and became a burr is formed in the recess. By flowing in, it is suppressed that it flows out to the outer peripheral surface of a welding part, and generation | occurrence | production of the burr | flash in the outer peripheral surface of a welding surface can be suppressed. Therefore, the product appearance can be improved.

A recess is provided on the welding surface of the flange portion of the large-diameter cylindrical portion,
It is good to provide the convex part which can be fitted in the said recessed part and has a height larger than the depth of the said recessed part on the welding surface of the collar part of the said cylindrical attachment member.

  Thereby, since the collar part of a large diameter cylindrical part and the collar part of a cylindrical attachment member are positioned by fitting of a recessed part and a convex part, the collar part and cylindrical attachment member of a large diameter cylindrical part in the case of welding The state of contact with the heel portion can be made more reliable.

  Further, since the height of the convex portion is larger than the depth of the concave portion, a gap is formed between the flange portion of the large diameter cylindrical portion and the flange portion of the cylindrical mounting member. A part of the gap fills up the gap, forming a welded state between the flange of the large-diameter cylindrical portion and the flange of the cylindrical mounting member, and suppressing molten resin from flowing out to the outer peripheral surface of the weld. The occurrence of burrs on the outer peripheral surface of the welded portion is suppressed.

  It is good to provide a site | part with a larger diameter than the area | region where the said large diameter cylindrical part contacts in the inner side of the said trunk | drum part in the outer peripheral surface of the said cylindrical attachment member.

Thereby, even if the welding state between the large-diameter cylindrical portion and the cylindrical mounting member is interrupted for some reason, the large-diameter portion of the cylindrical mounting member becomes caught so that the cylindrical mounting member becomes the large-diameter cylindrical portion. And slipping out of the space between the housing and the housing are suppressed.

  It is good to provide the projection part which bites into the inner peripheral surface of the said large diameter cylindrical part by being clamp | tightened by the said fastening band on the outer peripheral surface of the said cylindrical attachment member.

  Even if the welded state between the large-diameter cylindrical portion and the cylindrical mounting member is interrupted for some reason, the cylindrical mounting member becomes large-diameter cylindrical portion due to the protrusion biting into the inner peripheral surface of the large-diameter cylindrical portion. And slipping out of the space between the housing and the housing are suppressed.

  Further, the protrusions bite into the inner peripheral surface of the large-diameter cylindrical portion, so that the grease filled in the boot is prevented from leaking between the large-diameter cylindrical portion and the cylindrical mounting member. .

  A groove portion extending in the axial direction is provided so as to open only on an outer peripheral surface of the convex thick portion of the cylindrical mounting member and an end surface on the inner side of the body portion of the convex thick portion of the cylindrical mounting member. Good.

  By providing such a groove in the convex thick part, when molding the cylindrical mounting member, the mold on the outer peripheral side of the cylindrical mounting member is used in the radial direction when releasing the mold by using the groove. It can be released by operating, or can be released by operating in the axial direction of the cylindrical mounting member. Accordingly, it is possible to increase the degree of freedom of the mold structure and molding method for molding the cylindrical mounting member.

  Further, by providing such a groove portion in the convex thick portion, it is possible to improve the dimensional accuracy by suppressing the occurrence of sink marks in the convex thick portion that is thicker than other portions.

  Further, since the groove portion is configured not to be exposed to the outside of the boot, it is possible to prevent the occurrence of a foreign matter biting into the groove portion or the rainwater accumulation, and the occurrence of cracks and corrosion can be suppressed.

  The large-diameter cylindrical portion may be provided with a protrusion that can be fitted into the groove.

  Thereby, the shift | offset | difference of the contact part of a large diameter cylindrical part and a cylindrical attachment member is suppressed.

  As described above, according to the present invention, excellent durability can be achieved.

  The best mode for carrying out the present invention will be exemplarily described in detail below with reference to the drawings. However, the dimensions, materials, shapes, relative arrangements, and the like of the components described in this embodiment are not intended to limit the scope of the present invention only to those unless otherwise specified. .

(Example 1)
With reference to FIGS. 1-3, the constant velocity joint boot concerning Example 1 of this invention is demonstrated. FIG. 1 is a schematic diagram illustrating the configuration of a constant velocity joint boot according to the present embodiment, where (a) is a cross-sectional view of a boot body, (b) is a cross-sectional view of a cylindrical mounting member, and (c) is a cross-sectional view. It is the figure which looked at the cylindrical attachment member (bottom surface) from the axial direction. FIG. 2 is a schematic cross-sectional view of a constant velocity joint boot according to the present embodiment. FIG. 3 is a diagram for explaining a method for manufacturing a constant velocity joint boot according to the present embodiment.

<Overview of constant velocity joints and constant velocity joint boots>
The constant velocity joint is a joint between an input shaft and an output shaft, which are provided so that the crossing angle can be changed, so that constant speed rotation can be transmitted from the input shaft to the output shaft. One of these shafts is provided with a housing (outer race) for housing bearing components. As for the housing, a tripod-shaped one has been used in order to reduce the thickness more than necessary for the purpose of reducing the weight and ensuring quietness.

  Here, the tripod shape is a shape in which three concave portions that are recessed in a curved shape (arc shape) are provided at equal intervals on the center point side of a circle with respect to a circle. That is, the tripod shape is a shape having three arc portions provided at equal intervals and three recessed portions provided between the arc portions.

  The constant velocity joint is provided with a constant velocity joint boot in order to contain a lubricant (generally grease) inside the joint and prevent water and mud from entering the joint. The constant velocity joint boot has one end fixed to the housing and the other end fixed to the other shaft. Therefore, the inner side of one end is configured in a tripod shape so as to follow the outer shape of the housing, and the inner side of the other end is configured to be circular. Further, constant velocity joint boots made of thermoplastic resin have been developed for the purpose of weight reduction.

<Configuration of boot according to this embodiment>
As shown in FIGS. 1 and 2, the constant velocity joint boot 1 includes a bellows-shaped body portion 10 configured to be freely extendable and bent, and cylindrical large-diameter tubular portions 11 provided at both ends thereof. A boot main body 1a having a small-diameter cylindrical portion 12 and a cylindrical attachment member 13 attached to the inner peripheral surface of the large-diameter cylindrical portion 11 are provided.

  The cylindrical mounting member 13 is an annular member called a so-called grommet, and is a member for fixing the large-diameter cylindrical portion 11 of the boot body 1a to a housing (not shown). The cylindrical mounting member 13 is formed in a tripod shape so that the inner peripheral surface thereof conforms to the outer shape of the housing, and convex thick portions 13a that protrude in the inner diameter direction are arranged at three locations on the inner peripheral surface. . The cylindrical mounting member 13 is mounted between the inner peripheral surface of the large diameter cylindrical portion 11 and the outer peripheral surface of the housing.

  The constant-velocity joint boot 1 has a large-diameter cylindrical portion 11 and a cylindrical mounting member 13, that is, the like, by tightening the outer peripheral surface of the large-diameter cylindrical portion 11 with a metal fastening band (not shown). One end of the fast joint boot 1 is fixed to the housing. Further, the small diameter cylindrical portion 12 is fixed to the other shaft.

  The large-diameter cylindrical portion 11 has a fastening portion 11a of the fastening band on its outer peripheral surface, and a flange projecting in a flange shape in the outer diameter direction at the end opposite to the body portion 10 with the attachment portion 11a interposed therebetween. Part 11b. Moreover, the cylindrical attachment member 13 has the collar part 13b which protrudes in a flange shape from the edge part of the one end side of the outer peripheral surface to an outer diameter direction. Each of the flange portion 11b and the flange portion 13b has a uniform protrusion amount (diameter dimension) over the entire circumference.

  At the boundary between the large-diameter cylindrical portion 11 and the body portion 10, a step portion 10a having a surface extending in the outer diameter direction from the outer peripheral surface (attachment portion 11a) of the large-diameter cylindrical portion 11 is provided. The attachment part 11a of the fastening band is sandwiched between the step part 10a and the flange part 11b and forms an annular recess that is recessed in the inner diameter direction.

  Further, the flange portion 11b of the large-diameter cylindrical portion 11 and the flange portion 13b of the cylindrical mounting member 13 are in contact with each other when the cylindrical mounting member 13 is mounted on the inner peripheral surface of the large-diameter cylindrical portion 11. The contact surface is welded. In this way, the boot body 1a and the cylindrical mounting member 13 are integrally coupled to constitute the constant velocity joint boot 1.

<The manufacturing method of the boot which concerns on a present Example>
The constant velocity joint boot 1 according to the present embodiment is manufactured by separately manufacturing the boot body 1a and the cylindrical mounting member 13 and welding them together. As a welding method, laser welding is used in the present embodiment, but the present invention is not limited to this, and other welding methods such as ultrasonic welding and vibration welding can also be employed.

  The boot body 1a is manufactured by blow molding. Since the boot body 1a has a shape with no change in thickness in the circumferential direction, it can be suitably manufactured by general blow molding. On the other hand, the cylindrical mounting member 13 whose thickness changes at the convex thick portion 13a is manufactured by injection molding.

  As shown in FIG. 3, the fixing jig 200 is attached to the outer peripheral surface of the large-diameter cylindrical portion 11 (attachment portion 11 a of the fastening band), and on the side surface (end surface) of the flange portion 13 b of the cylindrical attachment member 13. The pressure welding jig 300 is brought into contact. As the pressure welding jig 300, for example, a laser transmitting material (glass plate or the like) is used for laser welding, and a welding horn or the like is used for ultrasonic welding.

  The contact surface between the flange portion 11b of the large-diameter cylindrical portion 11 and the flange portion 13b of the cylindrical mounting member 13 is loaded with melting energy while being pressed by the pressure welding jig 300 at a pressure suitable for each welding method. By doing so, it is welded uniformly and firmly over the entire circumference.

A protrusion 13c such as a rib is provided on the welding surface of the flange 13b with the flange 11b in order to perform more reliable welding. Further, when performing laser welding, a laser transmitting material is used as the material of the cylindrical mounting member 13.
<Excellent points of this embodiment>
Generally, in a constant velocity joint boot, a small-diameter cylindrical portion and a large-diameter cylindrical portion at both ends of the boot body are respectively fixed to a shaft and an outer race by a metal fastening band. Between the tightening bands, stresses are always applied due to repeated expansion and contraction of the boot (bellows portion) during traveling. Therefore, if the welded part between the large-diameter cylindrical part and the cylindrical mounting member is provided between the small-diameter fixed part and the large-diameter fixed part, the welded part is stressed and easily cracks. End up. In this embodiment, the welding part is provided outside the fastening band fixing part. Thereby, since the stress due to the expansion and contraction of the boot is not directly applied to the welded portion, the life of the boot can be extended.

  Further, in this embodiment, the flange portions 11b and 13b protruding in a flange shape in the outer diameter direction respectively provided on the large-diameter cylindrical portion 11 and the cylindrical mounting member 13 are pressed and welded together with an appropriate pressure. A more complete sealed state can be suitably formed by welding. That is, it has a configuration in which the flat surfaces of the flange portions 11b and 13b provided on the large-diameter cylindrical portion 11 and the cylindrical mounting member 13 are welded to each other, and it is easy to press the entire welding surface uniformly. Compared with welding of cylindrical surfaces, a more complete adhesion state can be formed. Therefore, it is possible to improve the integrity of the large-diameter cylindrical portion 11 (boot body 1a) and the cylindrical mounting member 13.

  Moreover, since the adhesiveness of the large diameter cylindrical part 11 and the cylindrical attachment member 13 is improved, the grease leak from between the boot main body 1a and the cylindrical attachment member 13 can be prevented suitably. Further, by integrating the boot main body 1a and the cylindrical mounting member 13 by welding, separation at the time of assembling the boot 1 can be prevented.

Further, in this embodiment, the flange portion 11b is provided adjacent to the tightening band attaching portion 11a in the large-diameter cylindrical portion 11, and the tightening band is positioned by the flange portion 11b. Wearability is improved. Moreover, since the collar parts 11b and 13b are provided with the uniform protrusion amount over the perimeter, it can prevent the position shift | offset | difference and removal of a fastening band suitably.

(Example 2)
With reference to FIGS. 4-6, the boot for constant velocity joints based on Example 2 of this invention is demonstrated. FIG. 4 is a schematic half sectional view of the constant velocity joint boot according to the present embodiment. FIG. 5 is an enlarged schematic cross-sectional view of the convex thick portion, where (a) shows a comparative example and (b) shows a cross-sectional view of the present embodiment. FIGS. 6A and 6B are schematic views of the convex thick portion viewed from the axial direction, where FIG. 6A is a first modification, FIG. 6B is a second modification, and FIG. 6C is a schematic view of the present embodiment. .

  Hereinafter, matters that are not particularly described are the same as those in the above-described embodiment, and the same components are denoted by the same reference numerals, description thereof is omitted, and only different points will be described.

  As shown in FIG. 4, in the constant velocity joint boot 2 according to the present embodiment, a hollow portion (thickening portion) 13 d is provided in the convex thick portion 13 a of the cylindrical mounting member 13.

  The hollow portion 13d is provided to suppress the occurrence of sink marks in the convex thick portion 13a after the cylindrical mounting member 13 is molded, so that the thickness of the cylindrical mounting member 13 becomes uniform as a whole. Formed.

  In general, in the cylindrical mounting member 13 that is injection-molded, a thick portion such as the convex thick portion 13a causes sink marks after molding. In order to suppress the occurrence of this sink, it is necessary to take measures such as taking a long cooling time and a long pressure holding time during molding. However, since such a treatment requires time, the tact time becomes long and the product cost increases.

  Therefore, in this embodiment, the hollow portion 13d is formed by raising a pin or the like at the portion where the convex thick portion 13a is formed in the molding die.

  Moreover, as shown in FIG.4 and FIG.5 (b), the cavity part 13d is the end surface (the side opposite to the edge part in which the collar part 13b was provided) of the cylindrical attachment member 13 which faces the inner side of the fuselage | body part 10. As shown in FIG. (End surface of the end portion) 13e is provided so as to open.

  In the constant velocity joint boot as in the present embodiment, chamfering is performed on the boot end surface (inner diameter side corner of the end surface of the cylindrical mounting member 13) so that the boot can be easily attached to the outer race (the tapered surface is formed). It is preferred that However, as shown in FIG. 5 (a), the hollow portion 13d opens at the end surface of the cylindrical mounting member 13 opposite to the inside of the boot, that is, the end surface on the housing side (the end surface exposed to the outside of the boot). If it is provided in this manner, a chamfering is performed, so that a very thin portion T is formed in the region of the tip end of the tapered surface at the inner diameter side corner of the end surface of the cylindrical mounting member 13. Such a thin-walled portion T is easily cracked when subjected to a load from the external environment, and is easily cracked due to its low strength during mounting and other handling.

  Further, in order to prevent the thin portion T from being formed, for example, a method of narrowing the width of the cavity 13d in the vicinity of the opening in accordance with the chamfered shape using a pin or the like having a thin root side is adopted because it is difficult to release the mold. Can not. Therefore, if it is attempted to prevent the thin portion T from being formed while the width of the hollow portion 13d remains uniform, the thickness on the inner diameter side of the convex thick portion 13a must be increased, and the thickness can be made uniform. There is a limit.

As shown in FIG. 5B, in this embodiment, the hollow portion 13d is provided so as to be exposed at the inner side of the body portion 10, that is, open at the end surface 13e opposite to the end surface where chamfering is formed. This makes it possible to obtain a more uniform wall thickness. That is, there is no problem in releasability even if the width of the bottom side of the cavity portion 13d is reduced by using a pin or the like whose tip side is thin in accordance with the chamfered shape. The thickness can be made uniform.

  In this embodiment, the hollow portion 13d has a cylindrical shape as shown in FIG. 6C. For example, the hollow portion 13d has a cylindrical shape as in Comparative Example 2 shown in FIG. 6B. It is good also as a structure which provides two (13d ''), and also like the comparative example 1 shown to Fig.6 (a), it is the shape of a substantially triangular prism-shaped irregular shape so that it may match the shape of a more convex thick part. A thing (13d ') may be provided.

<Excellent points of this embodiment>
By providing the hollow portion 13d in the convex thick portion 13a, it is possible to suppress the occurrence of sink marks in the convex thick portion 13a that is thicker than other portions and improve the dimensional accuracy.

  Further, by providing the cavity portion 13d so as to open at the end surface opposite to the end surface where chamfering is formed, the cavity portion 13d having a shape corresponding to the chamfered shape can be formed. Therefore, a more uniform wall thickness can be obtained.

  Further, since the hollow portion 13d is not exposed to the outside of the boot, it is possible to prevent foreign matter from being caught in the hollow portion 13d, rainwater accumulation, and the like, and to suppress the occurrence of cracks and corrosion.

  The structure in which the hollow portion 13d that opens to the inside of the boot is formed in such a shape that cannot be formed (formed) by the injection blow molding or the two-stage molding described in the prior art. And the cylindrical mounting member can be applied only by a structure manufactured separately.

(Example 3)
With reference to FIG.7 and FIG.8, the boot for constant velocity joints concerning Example 3 of this invention is demonstrated. FIG. 7 is a schematic cross-sectional view illustrating a configuration of a fixed portion between a constant velocity joint boot and a housing (outer race) according to the related art. It is typical sectional drawing explaining the structure of the fixing | fixed part of the boot for constant velocity joints and a housing (outer race) which concern on a present Example.

  Hereinafter, matters that are not particularly described are the same as those in the above-described embodiment, and the same components are denoted by the same reference numerals, description thereof is omitted, and only different points will be described.

  As shown in FIG. 7, in the constant velocity joint boot 100 according to the prior art, when the large-diameter cylindrical portion 103 is incorporated in the housing (outer race) 400, an annular recess provided on the peripheral surface of the housing 400. The large-diameter cylindrical portion 103 is positioned with respect to the housing 400 by fitting the groove 400 a with the annular convex portion 103 a provided on the inner peripheral surface of the large-diameter cylindrical portion 103. However, the convex shape that can be formed by blow molding has a low step height, and the degree of change in the step changes little by little. For this reason, the assembly position is easily displaced, and the position in the axial direction is accompanied by some variation.

  As shown in FIG. 8, in the constant velocity joint boot 3 according to the present embodiment, a small-diameter portion 13 f extending in a flange shape in the inner diameter direction is provided at the end of the cylindrical mounting member 13 on the inner side of the boot. An annular groove 13 g is provided on the outer peripheral surface of the cylindrical mounting member 13, and a convex portion 11 d that can be fitted into the groove 13 g is provided on the inner peripheral surface of the large-diameter cylindrical portion 11.

  In the constant velocity joint boot 3 according to the present embodiment, when the large diameter cylindrical portion 11 is assembled to the housing 400, the small diameter portion 13 f abuts against the shoulder portion 401 of the housing 400, so that the axial direction is relative to the housing 400. Is positioned.

  Moreover, it is comprised so that the shift | offset | difference of the contact part of the large diameter cylindrical part 11 and the cylindrical attachment member 13 may be suppressed by the uneven | corrugated fitting of the convex part 11d and the concave groove 13g.

<Excellent points of this embodiment>
Since the small-diameter portion 13f abuts against the shoulder portion 401 of the housing 400, the small-diameter portion 13f is accurately positioned with respect to the housing 400. Therefore, positioning during assembly is facilitated, and assemblability is improved. In addition, since the positioning is performed accurately, there is no difference in position for each joint, and a stable life can be obtained (long life).

  Further, the load generated when the boot is contracted is received by the cylindrical mounting member 13 by the small diameter portion 13f coming into contact with the shoulder portion 401 of the housing 400, so that the tightening band 500 and the boot body 1a are applied. The load on the boots is reduced, and the occurrence of misalignment of the boot can be suppressed.

  The structure in which the small-diameter portion 13f is provided at the end portion on the inner side of the boot of the cylindrical mounting member 13 as described above is a shape that cannot be handled (formed) by the injection blow molding or the two-stage molding described in the prior art. As an example, the present invention can be applied only by a configuration in which the boot body and the cylindrical mounting member are manufactured separately.

(Example 4)
A constant velocity joint boot according to a fourth embodiment of the present invention will be described with reference to FIGS. FIG. 9 is a schematic cross-sectional view showing a state of laser welding of the boot main body 1a and the cylindrical mounting member 13 in the constant velocity joint boot 1 according to the first embodiment, and (a) shows a normal welding state. (B) has shown the welding state when a malfunction arises. FIG. 10 is a schematic cross-sectional view in the vicinity of the welded portion between the large-diameter cylindrical portion and the cylindrical mounting member of the constant velocity joint boot 4 according to the present embodiment.

  Hereinafter, matters that are not particularly described are the same as those in the above-described embodiment, and the same components are denoted by the same reference numerals, description thereof is omitted, and only different points will be described.

  As shown in FIG. 9A, in Example 1, the laser beam 300a is transmitted through the cylindrical mounting member 13 made of a laser-transmitting resin to the welding surface of the flange portion 11b with the flange portion 13b, and melted. A structure in which a welded state between the flat surfaces of the flange portion 11b and the flange portion 13b is formed by pressing the protruding portion 13c such as a rib provided on the flange portion 13b into the welding surface of the flange portion 11b. It has become. In addition, the welding surfaces of the flange portion 11b and the flange portion 13b are absorbed by melting of the flange portion 11b if unevenness or burrs of a certain size, and if the biting of the protrusion portion 13b is secured to some extent, A sufficient welding state can be formed.

  However, for example, as shown in FIG. 9B, when the burr 11 c that is out of the irradiation range of the laser beam 300 a and is higher than the protrusion 13 c is formed on the welding surface of the flange 13 b, It is conceivable that a sufficient contact state between 11b and the flange 13b cannot be formed and welding cannot be performed, or a sufficient welding strength cannot be obtained. In the boot body 1a manufactured by blow molding, burrs 11c are easily formed on the end surface (welded surface of the flange portion 11b) of the large-diameter cylindrical portion 11 after molding, and when the burrs 11c are large, the flange portions 11b and the flange portions are formed. A finishing process such as cutting the burr 11c to a height (usually within 0.2 mm) that does not hinder the welding with 13b is required.

  Therefore, in this embodiment, as shown in FIG. 10, a recess 13h for allowing the above-described burr 11c to escape is provided in the flange 13b. The recess 13h is formed in an annular shape on the welding surface of the flange 13b at a position corresponding to a region where a burr is formed in the flange 11b (parting line of the mold). The size (depth, width, etc.) of the recess 13h is appropriately set according to various specifications.

<Excellent points of this embodiment>
By providing the recess 13h in the flange 13b for releasing the burr formed on the flange 11b, it is possible to more reliably form a welded state between the flat surfaces of the flange 11b and the flange 13b.

  In addition, the size of the burrs that are allowed increases, and the number of manufacturing steps can be reduced by eliminating the need to remove burrs.

  Moreover, in the welding surface of the flange part 11b and the flange part 13b, a part of the melted resin that has flowed to the outer peripheral surface of the weld part and has become burr in the past flows into the concave part 13b, so that the outer peripheral surface of the weld part It is suppressed that it flows out to. Thereby, generation | occurrence | production of the burr | flash in the outer peripheral surface of a welding part is suppressed, and a product external appearance can be improved.

(Example 5)
With reference to FIGS. 11 and 12, a constant velocity joint boot according to Embodiment 5 of the present invention will be described. FIG. 11 is a schematic cross-sectional view showing a state in which the boot main body 1a and the cylindrical mounting member 13 are welded to each other in the constant velocity joint boot 1 according to the first embodiment. FIG. 12 is a schematic cross-sectional view in the vicinity of the welded portion between the large-diameter cylindrical portion and the cylindrical mounting member of the constant velocity joint boot 5 according to the present embodiment, (a) is this embodiment, (b). These show sectional views in modifications of the present embodiment.

  Hereinafter, matters that are not particularly described are the same as those in the above-described embodiment, and the same components are denoted by the same reference numerals, description thereof is omitted, and only different points will be described.

  In the configuration in which the flange portion 11b and the flange portion 13b are welded at the welding surface perpendicular to the axis as in the first embodiment, a part of the resin melted at the time of welding flows out to the outer peripheral surface of the welding portion, and the burrs. It may become. Such burrs may require a finishing process such as removal for reasons such as product quality.

  On the other hand, in laser welding, if the welding surfaces are not sufficiently in contact with each other during welding, the welding strength may decrease. Therefore, it is necessary to fix and weld so that a load always acts on the flange part 11b and the flange part 13b at the time of welding so that the welding surface is always in close contact during welding. However, if the load for bringing the flange portion 11b and the flange portion 13b into close contact is too large, as shown in FIG. 11, the inner peripheral surface of the large-diameter cylindrical portion 11 falls off as if it rides on the flange portion 13b. In some cases, welding cannot be performed.

  Therefore, in this embodiment, as shown in FIGS. 12A and 12B, concave portions 11e and 11f are provided on the welding surface of the flange portion 11b, and convex portions 13i and 13j that can be fitted into the concave portions 11e and 11f. Is provided on the flange 13b. The height of the convex portions 13i and 13j is set to be greater than the depth of the concave portions 11e and 11f, whereby a gap G is formed between the welding surfaces of the flange portion 11b and the flange portion 13b.

The welding of the flange portion 11b and the flange portion 13b is performed by irradiating the concave portions 11e and 11f with laser light (not shown), and a part of the resin melted and flows out fills the gap G, or the flange portion 11
The protrusions 13i and 13j deeply bite into the recesses 11e and 11f by melting b, so that the flat surfaces of the flange part 11b and the flange part 13b are in close contact with each other and are welded.

  Here, the size (depth, height, width, etc.) of the recesses 11e and 11f and the protrusions 13i and 13j can maintain the gap G even when a load is applied to the flange portion 11b and the flange portion 13b. In accordance with various specifications and the like within a range where a molten resin can flow out and a sufficient welded state can be formed between the flange 11b and the flange 13 by the resin flowing into the gap G. Is set as appropriate.

<Excellent points of this embodiment>
Since the flange 11b and the flange 13b are positioned by fitting the recesses 11e and 11f and the protrusions 13i and 13j, even if the flange 11b and the flange 13b are pressed against each other, as shown in FIG. The falling state is suppressed, and the contact state between the flange portion 11b and the flange portion 13b at the time of welding can be made more reliable.

  Further, a gap G is formed between the flange portion 11b and the flange portion 13b at the time of welding, and the resin that melts and flows out from the concave portions 11e and 11f irradiated with the laser light is configured to fill the gap G. The generation | occurrence | production of the burr | flash in the welding part outer peripheral surface of a collar part is suppressed.

(Example 6)
With reference to FIG. 13, a constant velocity joint boot according to Embodiment 6 of the present invention will be described. 13A and 13B are schematic cross-sectional views of the cylindrical mounting member 13 of the constant velocity joint boot according to the present embodiment. FIG. 13A is a cross-sectional view of the present embodiment, and FIG. 13B is a cross-sectional view of a modification of the present embodiment. Each is shown.

  Hereinafter, matters that are not particularly described are the same as those in the above-described embodiment, and the same components are denoted by the same reference numerals, description thereof is omitted, and only different points will be described.

  In the configuration in which the inner peripheral surface of the bellows portion large-diameter cylindrical portion and the outer peripheral surface of the grommet are welded as in the conventional case, repeated stress is easily applied to the welded portion by bending or sliding of the joint, for long-term use or Since the welded state of the welded portion is insufficient, the welded portion may break or the like, and the welded state between the bellows portion and the grommet may be interrupted (disappeared). In such a case, there is a concern that the grommet may fall off between the bellows portion large-diameter cylindrical portion and the housing.

  Moreover, also in the said Example 1, since the internal peripheral surface of the large diameter cylindrical part 11 and the outer peripheral surface of the cylindrical attachment member 13 are not welded, a contact surface becomes a surface extended along an axis | shaft. Therefore, if the welded state between the large-diameter cylindrical portion 11 and the cylindrical mounting member 13 is interrupted for some reason, the cylindrical mounting member 13 is interposed between the large-diameter cylindrical portion 11 and the housing. There is concern that it will fall off.

  In the present embodiment, on the outer peripheral surface of the cylindrical mounting member 13, a portion having a larger diameter than the contact area with the large-diameter cylindrical portion 11 on the outer side of the boot (on the opposite side to the trunk portion 10) In the case where the welded portion between the large-diameter cylindrical portion 11 and the cylindrical mounting member 13 is broken, the large-diameter portion is caught and the cylindrical mounting member 13 is large. It was made to suppress that it slips out from between the diameter cylindrical part 11 and a housing.

Various specific configurations of the contact surface of the cylindrical mounting member 13 with the large-diameter cylindrical portion 11 can be adopted. For example, as shown in FIG. 13A, the cylindrical mounting member 13 The outer peripheral surface can be a tapered surface 13k. Further, as shown in FIG. 13 (b), even if a protruding portion 131 that protrudes in the outer diameter direction is provided on the inner side of the boot from the region where the large-diameter cylindrical portion 11 on the outer peripheral surface of the cylindrical mounting member 13 contacts. Good.

  On the other hand, the large-diameter cylindrical portion 11 may have, for example, an inner peripheral surface having a small-diameter portion and a large-diameter portion corresponding to the shape of the cylindrical mounting member 13, or perpendicular to the conventional axis. It may be made to have a cylindrical shape and be tightened by a fastening band (not shown) to be deformed and brought into close contact with the outer peripheral shape of the cylindrical mounting member 13.

<Excellent points of this embodiment>
As described above, when the large-diameter portion provided on the inner side of the boot on the outer peripheral surface of the cylindrical mounting member 13 is caught, the cylindrical mounting member 13 is externally connected between the large-diameter cylindrical portion 11 and the housing. It is prevented from slipping out. Therefore, even if the welding state between the large-diameter cylindrical portion 11 and the cylindrical mounting member 13 is interrupted for some reason, the cylindrical mounting member 13 is displaced from the gap between the large-diameter cylindrical portion 11 and the housing. Is prevented.

(Example 7)
With reference to FIG. 14, a constant velocity joint boot according to Embodiment 7 of the present invention will be described. FIG. 14 is a schematic cross-sectional view in the vicinity of the welded portion between the large-diameter tubular portion and the tubular mounting member of the constant velocity joint boot according to the present embodiment.

  Hereinafter, matters that are not particularly described are the same as those in the above-described embodiment, and the same components are denoted by the same reference numerals, description thereof is omitted, and only different points will be described.

  When the welded state between the large-diameter tubular portion 11 and the tubular mounting member 13 is interrupted for some reason, the tubular mounting member 13 may be dropped out as described above and filled in the boot. Grease leakage is also a concern.

  Therefore, in this embodiment, a protruding portion 13 m having a screw shape is provided on the outer peripheral surface of the cylindrical mounting member 13, and the male screw-shaped protruding portion 13 m of the large diameter cylindrical portion 11 is tightened by tightening the tightening band 500. It is configured to be attached to the housing in a state of biting into the inner peripheral surface.

  Note that the configuration of the protrusion 13m is not limited to the screw shape as described above, and a plurality of protrusions 13m that can bite into the inner peripheral surface of the large-diameter cylindrical portion 11 when tightened by the tightening band 500. Any other configuration can be adopted as long as it is an irregular shape. For example, a configuration in which a plurality of annular protrusions and grooves are arranged in the axial direction may be used.

<Excellent points of this embodiment>
Even if the welded state between the large-diameter cylindrical portion 11 and the cylindrical mounting member 13 is interrupted for some reason by the protrusion 13m biting into the inner peripheral surface of the large-diameter cylindrical portion 11, the cylindrical mounting member 13 Is prevented from slipping out of the space between the large-diameter cylindrical portion 11 and the housing.

Further, the protrusion 13 m bites into the inner peripheral surface of the large-diameter cylindrical portion 11, so that the grease filled in the boot leaks between the large-diameter cylindrical portion 11 and the cylindrical mounting member 13. Is prevented.
(Example 8)
A constant velocity joint boot according to an eighth embodiment of the present invention will be described with reference to FIGS. FIGS. 15A and 15B are perspective views of the cylindrical mounting member 13 of the constant velocity joint boot 8 according to the present embodiment. FIG. 15A is a perspective view of the present embodiment, and FIG. FIG. 16 is a perspective view of the boot body 1a of the constant velocity joint boot 8 according to this embodiment. FIG. 17 is a schematic cross-sectional view in the vicinity of the welded portion between the large-diameter cylindrical portion and the cylindrical mounting member of the constant velocity joint boot 8 according to the present embodiment.

  Hereinafter, matters that are not particularly described are the same as those in the above-described embodiment, and the same components are denoted by the same reference numerals, description thereof is omitted, and only different points will be described.

  As shown in FIG. 15, in this embodiment, the convex thick portion 13a of the cylindrical mounting member 13 is axially opened so as to open only on the outer peripheral surface of the convex thick portion 13a and the end surface on the boot inner side. An extending groove 13n is provided.

  In addition, as shown in FIG. 16, in this embodiment, a protrusion 11g that can be fitted into the groove 13n of the cylindrical mounting member 13 is provided on the inner peripheral surface of the large-diameter cylindrical portion 11 of the boot body 1a. Yes.

  Therefore, as shown in FIG. 17, in this embodiment, the large-diameter cylindrical portion 11 and the cylindrical mounting member 13 are welded in a state where the protruding portion 11g is fitted in the groove portion 13n.

<Excellent points of this embodiment>
By providing the groove 13n as described above, when the cylindrical mounting member 13 is molded, the mold on the outer peripheral side of the cylindrical mounting member 13 is operated in the radial direction at the time of mold release using the groove 13n. It is possible to mold or release by actuating the cylindrical mounting member 13 in the axial direction. Therefore, the mold structure for molding the cylindrical mounting member 13 and the degree of freedom of the molding method can be increased.

  Further, similarly to the hollow portion 13d of the second embodiment, it is possible to suppress the occurrence of sink marks in the convex thick portion 13a which is thicker than other portions while suppressing the intrusion of foreign matters from the outside and the like. Can be improved.

  Further, by providing the projection 11g as described above, it is possible to suppress the deviation between the large-diameter cylindrical portion 11 and the cylindrical mounting member 13, and for some reason the large-diameter cylindrical portion 11 and the cylindrical shape. When the welded state with the mounting member 13 is interrupted, the cylindrical mounting member 13 can be prevented from slipping out of the space between the large-diameter cylindrical portion 11 and the housing.

  In addition, as shown in FIG.15 (b), you may provide the groove part 13n with respect to the one convex thick part 13a.

  The configurations of the above embodiments can be employed in combination as much as possible.

3 is a schematic diagram illustrating a configuration of a constant velocity joint boot according to Embodiment 1. FIG. 1 is a schematic cross-sectional view of a constant velocity joint boot according to Embodiment 1. FIG. It is a figure explaining the manufacturing method of the boots for constant velocity joints which concern on Example 1. FIG. 6 is a schematic half cross-sectional view of a constant velocity joint boot according to Embodiment 2. FIG. It is typical sectional drawing which expands and shows the part of a convex-shaped thick part. It is the schematic diagram which looked at the convex thick part from the axial direction. It is typical sectional drawing explaining the structure of the fixing | fixed part of the boot for constant velocity joints and a housing (outer race) which concern on a prior art. FIG. 10 is a schematic cross-sectional view illustrating a configuration of a fixed portion between a constant velocity joint boot and a housing (outer race) according to a third embodiment. It is typical sectional drawing which shows the mode at the time of the laser welding of the boot main body and the cylindrical attachment member in the boot for constant velocity joints based on Example 1. FIG. FIG. 10 is a schematic cross-sectional view in the vicinity of a welded portion between a large-diameter tubular portion and a tubular mounting member of a constant velocity joint boot according to a fourth embodiment. It is typical sectional drawing which shows the mode at the time of the laser welding of the boot main body and the cylindrical attachment member in the boot for constant velocity joints based on Example 1. FIG. FIG. 9 is a schematic cross-sectional view in the vicinity of a welded portion between a large-diameter tubular portion and a tubular mounting member of a constant velocity joint boot according to a fifth embodiment. FIG. 10 is a schematic cross-sectional view of a cylindrical mounting member of a constant velocity joint boot according to a sixth embodiment. FIG. 10 is a schematic cross-sectional view in the vicinity of a welded portion between a large-diameter tubular portion and a tubular mounting member of a constant velocity joint boot according to a seventh embodiment. It is a perspective view of the cylindrical attachment member of the boot for constant velocity joints which concerns on Example 8. FIG. FIG. 10 is a perspective view of a boot body of a constant velocity joint boot according to an eighth embodiment. FIG. 10 is a schematic cross-sectional view in the vicinity of a welded portion between a large-diameter tubular portion and a tubular mounting member of a constant velocity joint boot according to Embodiment 8. It is a schematic diagram explaining the structure of the boot for constant velocity joints which concerns on a prior art.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Boot for constant velocity joints 1a Boot main body 10 Body part 10a Step part 11 Large diameter cylindrical part 11a Mounting part 11b Hook part 11c Protrusion part 11d Convex part 12 Small diameter cylindrical part 13 Cylindrical attachment member 13a Convex thick part 13b Gutter part 13c Protrusion part 13d Cavity part 13e End face 13f Small diameter part 13g Concave groove 200 Fixing jig 300 Pressure welding jig 400 Housing 401 Shoulder part 500 Tightening band

Claims (10)

A cylindrical body having a flexible bellows shape;
A small-diameter cylindrical portion attached to one of the two shafts provided at one end of the body portion and capable of changing the crossing angle with each other;
A boot body having a large-diameter tubular portion provided at the other end of the body portion and attached to a housing that accommodates the other of the two shafts;
A cylindrical mounting member that is interposed between the inner peripheral surface of the large-diameter cylindrical portion and the outer peripheral surface of the housing and has a convex thick portion that protrudes in the inner diameter direction along the outer shape of the housing. And comprising
In the constant velocity joint boot fixed to the one shaft and the housing by a fastening band attached to the outer peripheral surface of the small diameter cylindrical portion and the large diameter cylindrical portion,
A flange portion extending in a flange shape in the outer diameter direction is provided at an end of the large-diameter cylindrical portion opposite to the body portion side,
The tubular mounting member is provided with a flange portion that comes into contact with the flange portion of the large-diameter tubular portion,
A boot for a constant velocity joint, wherein a contact surface between a flange portion of the large-diameter cylindrical portion and a flange portion of the cylindrical mounting member is welded. While chamfering the inner diameter side corner of the end surface of the tubular mounting member opposite to the inner side of the body portion,
2. The constant velocity joint boot according to claim 1, wherein the convex thick wall portion is provided with a hollow portion that opens at an end face on the inner side of the body portion of the cylindrical mounting member.   3. A small-diameter portion that extends in a flange shape in the inner diameter direction and abuts against a shoulder portion of the housing is provided at an end portion on the inner side of the body portion of the cylindrical mounting member. Boots for constant velocity joints.   The constant velocity joint according to any one of claims 1 to 3, wherein an uneven fitting portion is provided between an outer peripheral surface of the cylindrical mounting member and an inner peripheral surface of the large-diameter cylindrical portion. Boots.   The constant velocity according to any one of claims 1 to 4, wherein a concave portion for releasing a burr formed in the flange portion of the large-diameter cylindrical portion is provided in the flange portion of the cylindrical mounting member. Joint boots. A recess is provided on the welding surface of the flange portion of the large-diameter cylindrical portion,
The convex part which can be fitted in the said recessed part and has a height larger than the depth of the said recessed part was provided in the welding surface of the collar part of the said cylindrical attachment member. The constant velocity joint boot described in 1.   The part which has a diameter larger than the area | region where the said large diameter cylindrical part contacts is provided in the inner side of the said trunk | drum part in the outer peripheral surface of the said cylindrical attachment member. The described constant velocity joint boot.   The protrusion part which bites into the inner peripheral surface of the said large diameter cylindrical part is provided in the outer peripheral surface of the said cylindrical attachment member by the said clamp | tightening band. The described constant velocity joint boot.   A groove portion extending in the axial direction is provided so as to open only at an outer peripheral surface of the convex thick portion of the cylindrical mounting member and an end surface on the inner side of the body portion of the convex thick portion of the cylindrical mounting member. The boot for a constant velocity joint according to any one of claims 1 to 8.   The constant-velocity joint boot according to claim 9, wherein the large-diameter cylindrical portion is provided with a protrusion that can be fitted into the groove.

Images