JPH0590055U - boots - Google Patents

Abstract

(57) [Summary] [Purpose] To improve the workability of wearing the boot and improve the airtightness inside the boot to prevent the boot from falling off. [Structure] A bellows portion 1 which is expandable and contractible in the axial direction and swingable with respect to the axial direction, and openings 2 and 3 at both ends of the bellows portion.
The outer surface 4 of at least one of the fixing parts 4 and 5 is a boot having fixing parts 4 and 5 in which
A plurality of concave grooves 6 are formed on a and 5a along the circumferential direction of the outer surface, and a plurality of raised portions 7 are formed on the inner surfaces 4b and 5b of the fixed portion along the circumferential direction of the inner surface.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a boot, for example, which is attached to a connecting portion between a drive shaft and a wheel and protects a constant velocity universal joint and the like constituting the connecting portion from rainwater, mud, etc., and particularly enhances workability of installing a boot. At the same time, it is a device that improves the tightness of the boot.

[0002]

[Prior Art]

 For example, a universal joint is used in a power transmission device that transmits the drive of an automobile engine to driving wheels. In particular, in FF vehicles (front engine front drive), the rotation of the engine crankshaft is decelerated by the final drive and then transmitted to the front wheels, which are the drive wheels, via the drive shaft. Although the rotation speed of the shaft is low, the drive wheels are steered wheels, so the bend angle between the drive shaft and the wheels is large. Therefore, a constant velocity universal joint (hereinafter, referred to as a constant velocity joint) has been conventionally used for a connecting portion between a drive shaft and a wheel of an FF vehicle.

The structure of a conventional connecting portion between a drive shaft and a wheel is as shown in FIG. That is, the outer ring 11 of the constant velocity joint 10 is fixed to a wheel (not shown), while the inner ring 12 of the constant velocity joint 10 is fixed to the drive shaft 13. Further, a ball 14 is interposed between the outer ring 11 and the inner ring 12, whereby the rotation speed of the drive shaft 13 is maintained equal and the wheel 14 is followed by the steering and the vertical movement. However, the driving force of the drive shaft 13 is transmitted to the wheels. Then, in order to protect the outer ring 11, the inner ring 12, and the ball 14 constituting the constant velocity joint 10 from rainwater, mud, etc., rubber or resin boots are provided between the drive shaft 13 and the outer ring 11. It is installed.

[0004]

[Problems to be solved by the device]

 By the way, the conventional boot has a bellows portion 1 which is capable of expanding and contracting in the axial direction, and openings 2 and 3 are formed at both ends of the bellows portion 1 to boot the outer ring 11 and the drive shaft 13 of the constant velocity joint 10. Fixing portions 4 and 5 for fixing the are formed. Then, the boots are firmly fixed by mounting the outer ring 11 and the shaft 13 while expanding the fixing portions 4 and 5, and finally tightening the stop band 8.

However, when the fixing parts 4, 5 of the boot are mounted on the outer ring 11 while being expanded, the boots are made of a material having elasticity such as rubber, regardless of whether they are made of synthetic resin or the like. When it is made of a rigid material, the mounting operation is extremely difficult. Therefore, conventionally, the shapes of the mounting parts such as the outer ring 11 and the drive shaft 13 of the constant velocity joint are appropriately changed depending on the material of the boot. In other words, in the case of rubber boots, the outer diameter of the outer ring 11 of the constant velocity joint could be set larger than the inner diameter of the openings 2, 3 of the boot, but in the case of resin boots, the outer ring of the constant velocity joint can be set. The outer diameter of 11 must be set to be almost equal to the inner diameter of the openings 2 and 3 of the boot, and as a result, rubber boots should be replaced with resin boots without changing the shape of the outer ring 11 or the like. I couldn't.

Even when the resin boot is used, the elastic force of the boot itself is smaller than that when the rubber boot is used, so that the fitting force between the outer ring and the fixing portion is mainly the fastening force of the stop band. Will be decided by. Therefore, if the fastening force of the stop band is not secured, the boot may fall out, or the sealing property between the boot and the outer ring may deteriorate.

The present invention has been made in view of the above problems of the prior art, and improves the workability of mounting the boot and improves the airtightness in the boot to prevent the boot from falling off. With the goal.

[0008]

[Means for Solving the Problems]

 In order to achieve the above object, the boot of the present invention comprises a bellows portion which is axially expandable and contractible and swingable with respect to the axial direction, and a fixed portion having openings formed at both ends of the bellows portion. In a boot having, a plurality of grooves are formed on the outer surface of at least one of the fixing portions along the circumferential direction of the outer surface, and the inner surface of the fixing portion has a circumferential direction of the inner surface. It is characterized by forming a plurality of raised portions along.

[0009]

[Action]

 For example, in order to protect the constant velocity joint that transmits the driving force of the drive shaft to the wheel from rainwater and mud, one of the fixing parts of the boot of the present invention is expanded and attached to the outer ring of the constant velocity joint, and the other is fixed. Similarly, mount the fixed part on the drive shaft while expanding it. At this time, since the boot of the present invention has a plurality of grooves along the circumferential direction on the outer surface of the fixing portion, even if the boot is made of high-rigidity synthetic resin, the grooves are bent and the fixing portion is deformed. Can be easily expanded. Therefore, the outer diameter of the constant velocity joint to which the boot of the present invention is to be mounted and the outer diameter of the drive shaft can be set to be larger than the inner diameter of the opening of the boot, thereby preventing the boot from slipping off. In addition, since the inner surface of the fixed part is formed with a plurality of ridges along the circumferential direction, when the boot of the present invention is mounted and tightened, contact between the constant velocity joint or the drive shaft and the inner surface of the fixed part occurs. The surface pressure increases, and as a result, the boot sealability improves.

[0010]

【Example】

 An embodiment of the present invention will be described below with reference to the drawings. 1A is a sectional view showing a boot according to an embodiment of the present invention, and FIG. 1B is an enlarged sectional view of a portion B in FIG. 1A. In the following description, the present invention will be described by taking a boot used for a constant velocity joint of a drive shaft as a specific example. Therefore, a configuration related to the constant velocity joint will be described with reference to FIG.

First, in the boot of this embodiment, openings 2 and 3 are formed at both ends of a tubular main body, and both ends thereof are the outer ring 11 and the drive shaft 13 of the constant velocity joint 10 shown in FIG. It is inserted and fixed in each. A bellows portion 1 is formed between the fixing portions 4 and 5 of the outer ring 11 and the drive shaft 13 so that the bellows portion 1 can be expanded and contracted and swung.

The material of the boot may be either rubber or synthetic resin, but in this embodiment, it is made of synthetic resin in order to reduce the weight of the boot. When it is made of synthetic resin, injection molding of the bellows part 1 is difficult, and therefore, it is preferable to form it by blow molding.

One of the fixing portions 4 of the boot of this embodiment is attached to the outer ring 11 of the constant velocity joint 10 and fixed by a stop band 8. The outer ring 11 of the constant velocity joint 10 is formed with an annular large-diameter portion 15 (the diameter of the large-diameter portion is shown as D1 in FIG. 2 and the diameter of the general portion is shown as D2), while fixing the boot. The inner surface of the portion 4 is formed in a shape that can be fitted into the annular large diameter portion 15. It is to be noted that such fixing means is not limited to the embodiment shown in FIG. 1, but various means can be used, but in order to prevent the boot from slipping off, a large diameter portion is provided at least at the end portion of the outer ring 11. It is preferable to form 15. The other fixing portion 5 of the boot is mounted on the outer peripheral surface of the drive shaft 13 and fixed by a stop band (not shown). An annular locking portion 16 is formed on the outer peripheral surface of the drive shaft 13 in order to prevent axial displacement of the boot. The fixing means is not limited to the embodiment shown in FIG. 4 and various means can be used.

When the boot of the present invention is applied to the constant velocity joint 10 of the drive shaft, since the outer diameter of the outer ring 11 of the constant velocity joint and the outer diameter of the drive shaft 13 are different, both openings 2 of the boot are formed. , 3 must be formed in accordance with the respective outer diameters of the outer ring 11 and the drive shaft 13. Therefore, the shape of the boot inevitably becomes a conical shape with the tip cut off as shown in FIG. 1, but the boot of the present invention is not limited to this shape, in short, both openings The parts 2 and 3 may be formed according to the member to be attached.

In the boot of this embodiment, a plurality of (three in the embodiment shown in FIG. 1) concave grooves are formed on the outer surface 4 a of the fixed portion 4 on the constant velocity joint 10 side along the circumferential direction of the fixed portion 4. 6 is formed. The groove 6 is preferably formed over the entire circumference of the fixing portion 4, but it may be formed partially. Further, the number of the concave grooves 6 is not particularly limited, but it is preferable to appropriately select it in consideration of the material (especially rigidity) of the synthetic resin forming the boot. Further, the shape of the concave groove 6 is not limited to the rectangular cross section shown in FIG. 1B, and may be appropriately selected according to the wall thickness of the fixed portion 4 and the molding conditions of blow molding. In particular, the depth and width of the concave groove 6 are the main factors that determine the function of how much the fixing portion 4 can be expanded, so the shape and dimensions of the outer ring 11 of the constant velocity joint that is the mounted member. It can be said that it is preferable to decide according to

Further, in the boot of this embodiment, a plurality (three in the embodiment shown in FIG. 1) of annular protrusions 7 are formed on the inner surface 4 b of the fixing portion 4 along the circumferential direction of the fixing portion 4. Is forming. The raised portion 7 is preferably formed over the entire circumference of the fixed portion 4, but it may be formed partially. Further, the number and shape of the raised portions 7 are not particularly limited, but the shape of the raised portions 7 is not limited to the mountain-shaped cross section shown in FIG. It may be selected appropriately according to the thickness and the molding conditions of blow molding. In particular, the height of the raised portion 7 is the main factor that determines the function of enhancing the sealing performance of the fixed portion 4, and therefore is determined according to the shape and size of the outer ring 11 of the constant velocity joint that is the mounted member. It can be said that it is preferable to keep it.

Further, the positional relationship between the concave groove 6 formed on the outer surface 4a of the fixed portion 4 and the raised portion 7 formed on the inner surface 4b does not need to be set at the same position as shown in the embodiment shown in FIG. Also, it is not necessary to make the number of settings equal. However, when blow molding is performed, since the convex portion for the concave groove is formed in the mold, when air is blown into the parison, the raised portion 7 is formed on the back side of the concave groove 6. Therefore, it is most preferable to set the positions of the recessed groove 6 and the raised portion 7 equally, as shown in FIG. 1, since it is not necessary to provide a special step of forming the raised portion 7.

Next, the operation will be described. FIG. 2 is an enlarged sectional view of an essential part for explaining a mounted state of the boot of the embodiment, and FIG. 3 is an enlarged sectional view of an essential part for showing a mounted state of the boot of the embodiment. One fixing portion 4 of the boot of this embodiment is inserted and fixed in the outer ring 11 of the constant velocity joint 10, and the other fixing portion 5 is inserted and fixed in the outer peripheral surface of the drive shaft 13. As a result, the inside of the boot is sealed and the constant velocity joint 10 can be protected from rainwater and mud.

At the time of this mounting work, it is necessary to open the fixing portion 4 of the boot larger than the large-diameter portion 15 of the outer ring 11 of the constant velocity joint, but the boot of this embodiment has a circumferential surface on the outer surface 4 a of the fixing portion 4. Since the plurality of recessed grooves 6 are provided along the direction, even in the case of a highly rigid resin boot, the recessed grooves 6 are bent as shown in FIG. 2 and the fixing portion 4 can be easily expanded. Therefore, the outer diameter of the outer ring 11 and the drive shaft 13 of the constant velocity joint to which the boot should be mounted can be set to be larger than the inner diameter d of the openings 2 and 3 of the boot, thereby preventing the boot from slipping off. it can. Further, since the inner surface 4b of the fixed portion 4 is formed with a plurality of raised portions 7 extending in the circumferential direction, when the boot is mounted and tightened with the retaining band 8, as shown in FIG. The contact surface pressure between the outer ring 11 of the joint and the inner surface 4b of the fixed portion 4 is increased, and as a result, the boot sealability is improved.

It should be noted that the boot of the present invention is not limited to the above-described embodiment and can be modified in various ways. For example, in the above-described embodiment, the boot of the present invention is applied to the constant velocity joint in which the members to be mounted expand and contract and swing, but the boot of the present invention is limited to the constant velocity joint. It is possible to apply it to all parts without. Further, the concave groove 6 and the raised portion 7 do not have to be formed in both fixing portions 4 and 5 as shown in FIG. 1, and may be either one.

[0021]

[Effect of the device]

 In the boot of the present invention, a plurality of recessed grooves are formed on the outer surface of at least one of the fixing portions along the circumferential direction of the outer surface, and the inner surface of the fixing portion is provided with the circumferential groove of the inner surface. Since a plurality of ridges are formed along the direction, the outer diameter of the outer ring or drive shaft of the constant velocity joint to which the boot of the present invention should be attached can be set to be larger than the inner diameter of the opening of the boot. It can be prevented from falling off. Further, since the inner surface of the fixed portion is formed with a plurality of ridges along the circumferential direction, when the boot of the present invention is mounted and tightened, the constant velocity joint or the drive shaft and the inner surface of the fixed portion are fixed. The contact surface pressure is increased, and as a result, the boot sealability is improved. Furthermore, since it is possible to form a large-diameter step on the outer ring of a constant velocity joint to which the boot should be attached, the boot having elasticity such as rubber and the boot made of highly rigid material such as synthetic resin are the same. It can be applied to shaped constant velocity joints, etc., increasing the versatility of boots.

[Brief description of drawings]

FIG. 1A is a sectional view showing a boot according to an embodiment of the present invention, and FIG. 1B is an enlarged sectional view of a portion B in FIG. 1A.

FIG. 2 is an enlarged sectional view of an essential part for explaining a mounted state of the boot of the embodiment.

FIG. 3 is an enlarged cross-sectional view of an essential part showing a state in which the boot of the embodiment is mounted.

FIG. 4 is a sectional view showing a conventional boot applied to a constant velocity joint.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Bellows part 2, 3 ... Opening part 4, 5 ... Fixed part 4a, 5a ... Outer surface 4b, 5b ... Inner surface 6 ... Recessed groove 7 ... Raised part 8 ... Stop band 10 ... Constant velocity universal joint 11 ... Outer ring 12 ... Inner ring 13 ... Drive shaft 14 ... Ball 15 ... Large diameter part

Claims (1)

[Scope of utility model registration request] 1. A bellows portion (1) which is expandable and contractible in the axial direction and swingable with respect to the axial direction, and a fixing portion (4) having openings (2, 3) formed at both ends of the bellows portion. In the boot having 5), a plurality of concave grooves (6) are formed on the outer surface (4a, 5a) of at least one of the fixing portions (4, 5) along the circumferential direction of the outer surface. However, the inner surface (4
b, 5b), a plurality of raised portions (7) formed along the circumferential direction of the inner surface of the boot.