JPH08232971A - Sealing structure of boot - Google Patents

Abstract

PURPOSE: To improve a sealing property by improving workability by way of eliminating necessity of applying a sealant intentionally at the time of installation and by ensuring filling of the sealant. CONSTITUTION: A band 6 to fill a sealant in a space 9 between an outer ring part 2a and a large diametrical fixing part 4 by way of squeezing it out to a passage 11 while crushing the space 9 by way of tightening the large diametrical fixing part 4 at the time of the space 9 provided in the large diametrical fixing part 4, a sealant enclosed in this space 9, the passage 11 to communicate the space 9 and the inside of the large diametrical fixing part 4 to each other and the large diametrical fixing part 4 on the outer ring part 2a in sealing structure of a boot 1 having the large diametrical fixing part 4 and installing this large diametrical fixing part 4 on the outer ring part 2a of a constant velocity joint 2.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a boot seal structure for covering a space between two members such as a constant velocity joint, a steering device, a cylinder device, etc. that are bent or expanded and contracted.

[0002]

2. Description of the Related Art Conventionally, when a boot is attached to a constant velocity joint or the like, especially when a high sealing property is required,
A sealant may be applied between the outer ring portion (fixed portion) of the constant velocity joint and the fixed portion of the boot. In particular, resin boots are harder and less adherent than rubber boots, so when assembling the fixed part of the boot to the outer ring part of the joint, instead of using an expensive band with higher tightening performance, so-called Applying a sealing agent to the boot mounting surface is effective as a means for ensuring the sealing property. In the case of this boot seal structure, in order to assemble the boot to the constant velocity joint, a sealant is applied in advance to the outer ring part of the joint or the fixed part of the boot, and then the fixed part is fitted into the outer ring part, and then this The outer periphery of the fixed part was tightened with a clamp such as a band.

A mating member whose cross-sectional contour of a portion (fixed portion) to which the boot is to be attached is not circular,
For example, when mounting a boot to a tripod type constant velocity joint in which the contour of the outer ring cross section is non-circular, the inside of the cross section of the boot fixing part molded to match the contour of the outer ring cross section Since the contour shape of is non-circular, the tightening force does not act uniformly and there is a problem that it is difficult to secure a sufficient sealing function. In particular, the seal is easily broken at the boundary portion of the unevenness on the boot mounting surface (the inner peripheral surface of the boot fixing portion). For this reason, even in a non-circular type boot, it is effective to apply a sealing agent to the boot mounting surface, especially the boundary portion of the unevenness, in order to secure the sealing function, but the boundary portion of the unevenness that requires sealing is effective. However, there is a problem that it is difficult to apply the sealing agent. Note that this is the same not only in the case of resin boots but also in the case of rubber boots where high sealability is required.

In some cases, such as steering boots used in automobiles, the sealing property is ensured by applying a sealing agent as in the above case.

[0005]

However, in the case of the conventional seal structure using the sealant, when the boot is assembled, the entire inner peripheral surface of the fixed portion of the boot or the boot mounting surface of the mating member, for example, the outer ring portion of the joint is mounted. Since a step of applying a sealant to the entire outer peripheral surface of the boot is required, the work of assembling the boot is troublesome and the productivity is poor. In particular, in a non-circular type boot, there is a part whose shape changes greatly on the boot mounting surface, and it is difficult to apply a sealant to this part,
It takes time and effort to apply. Further, in the non-circular type boot, since there is a portion where it is difficult to apply the sealant on the boot mounting surface, a portion where the sealant is not applied tends to remain on the seal mounting surface, and it is difficult to secure the sealing property. Further, if the mounting work is performed after applying the sealant first, the workability is poor.

Moreover, when the boot is assembled, since there is almost no gap between the boot fixing portion and the mating member, the applied sealant may be removed. Specifically, when performing the assembly work after applying the sealant to the inner peripheral surface of the fixed part of the boot, the sealant is pushed out into the boot and exists as foreign matter in the boot to ensure smooth operation of the constant velocity joint. Inhibit. On the other hand, when the assembling work is performed after applying the sealing agent to the boot mounting surface / outer peripheral surface of the mating member, the sealing agent must be pushed out of the boot and the protruding sealing agent must be wiped off.

The present invention provides a boot seal structure in which the work of applying a sealing agent at the time of assembly can be omitted and the workability is excellent, and moreover, the sealing agent is surely filled and the sealing performance is improved. The purpose is to

[0008]

In order to achieve such an object, the present invention is a boot having fixing parts attached to the outer peripheral surface of the mating member at both ends of the bellows part, and at least one of the fixing parts has a mating member. A space that can be crushed in the radial direction is provided while opening on the side of the inner peripheral surface that comes into contact with the liquid sealant.

Further, in the boot seal structure of the present invention, at least one circumferential passage communicating with the space is provided on the inner peripheral surface of the fixed portion. Here, the passage in the circumferential direction is constituted by, for example, a groove formed on the inner peripheral surface of the fixed portion, or an annular space between two sets of annular lips protruding from the inner peripheral surface. Further, in some cases, the circumferential passage is formed by a groove formed in the mating member.

In addition, in the boot seal structure of the present invention, the space is crushed by the tightening of the clamp means for attaching the fixed portion to the counterpart member, and the enclosed liquid sealant is applied to the inner peripheral surface of the fixed portion and the outer peripheral surface of the counterpart member. I am trying to be filled between.

[0011]

Therefore, according to the first aspect of the invention, after the fixing portion of the boot is fitted into the portion of the mating member where the boot is to be attached, the fixing portion is pressed inward in the radial direction by some means and the space in the fixing portion is increased. When crushed, the sealing agent enclosed in this space is pushed out between the inner peripheral surface of the fixed portion and the mating member, and is filled between the fixed portion and the mating member.

According to the second aspect of the present invention, the sealant pushed out toward the inner peripheral surface of the fixing portion due to the crushing of the space is spread in the circumferential direction through the passage, and further, in combination with the capillary phenomenon, the fixing agent is It is reliably filled with the mating member over the entire circumference.

According to the third aspect of the invention, the liquid sealant is simultaneously supplied by tightening the clamp means for firmly fixing the fixing portion of the boot to the mating member.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The structure of the present invention will be described in detail below with reference to the embodiments shown in the drawings.

FIG. 1 shows an embodiment of a boot to which the seal structure of the present invention is applied. The boot 1 of this embodiment is attached to a tripod type constant velocity joint 2 for an automobile. The tripod type constant velocity joint 2 (hereinafter abbreviated as tripod joint) has an outer ring portion 2a.
The boot 1 having a non-circular cross-sectional contour shape, in which, for example, three recesses are formed at equal intervals in the circumferential direction on the outer peripheral surface of the boot 1, is to be mounted.

The boot 1 is provided with a bellows portion 3, a large-diameter fixing portion 4 arranged at one end of the bellows portion 3 and fitted to the outer ring portion 2a of the constant velocity joint 2, and at the other end of the bellows portion 3. And a small-diameter fixed portion 5 fitted to the rotary shaft portion 2b of the constant velocity joint 2. The boot 1 is made of resin, for example. The large-diameter fixing part 4 and the small-diameter fixing part 5
Are fixed to the constant velocity joint 2 side by clamping means, for example, tightening bands 6 and 7 made of steel.

As shown in FIG. 2, a bulge 8 which projects radially inward is integrally formed on the inner peripheral surface 4a of the large-diameter fixing portion 4. The bulges 8 are arranged at three locations at equal intervals in the circumferential direction of the large-diameter fixing portion 4 corresponding to the recesses of the outer ring portion 2a of the tripod joint 2. Therefore, the contour shape inside the large-diameter fixing portion 4 is a non-circular shape that is substantially similar to the contour shape of the outer ring portion 2 a of the tripod joint 2.

In the boot 1 of this embodiment, a space 9 for enclosing a sealing agent is provided in the large-diameter fixing portion 4 by utilizing each bulge 8. Each bulge 8 has, for example, a hole 1 drilled at two locations.
A space 9 is formed by 2. The holes 12 are perforated side by side at a predetermined distance from the tip surface 8a of the bulging body 8. The space 9 in each hole 12 is filled with a liquid sealant, for example, a silicone-based liquid sealant, from the opening of the tip surface 8a. The opening of the hole 12 of the tip surface 8a is closed by the plug 10 after containing the liquid sealing agent, and the liquid sealing agent sealed when the space 9 is crushed leaks to the tip surface 8a side of the large-diameter fixing portion 4. It is provided to prevent this. As shown in detail in FIG. 3, each space 9 has an inner periphery of a boot fixing portion that contacts the inside of the bulging body 8, that is, the outer ring portion 2a that is a counterpart member, through a passage 11 formed toward the inner side in the radial direction. It is opened on the surface 4a side. The passages 11 are provided at two locations side by side in the longitudinal direction of the boot 1, for example, for each space 9. And when each space 9 is crushed,
The sealing agent sealed in the space 9 is provided so as to be pushed out from each passage 11 to the inner peripheral surface 4a side of the large-diameter fixing portion 4 of the boot 1. Then, the inner peripheral surface 4 of the boot fixing portion
a, at least on the inner peripheral surface 4a of each bulging body 8, a passage 11 is provided in order to facilitate the circumferential spreading of the sealant.
A groove 16 passing through the opening portion of is formed. Although the groove 16 is formed only in the thick bulging body 8, the groove 16 may be formed continuously over the entire circumference in some cases. The sealing agent may be enclosed in a capsule and then stored in the space 9, or may be directly filled in each space 9.

Next, a procedure for mounting the large-diameter fixing portion 4 of the boot 1 on the outer ring portion 2a of the constant velocity joint 2 will be described.

First, before mounting the boot 1, for example, when the boot is manufactured, a sealant is filled in each space 9 in advance. Then, the large-diameter fixing portion 4 of the boot 1 is fitted into the outer ring portion 2a of the constant velocity joint 2. The large-diameter fixing portion 4 is formed to have substantially the same diameter as the outer ring portion 2a. Therefore, the large-diameter fixing portion 4 is fitted into the outer ring portion 2a while sliding. In this case, since the sealing agent is sealed in the space 9, there is no risk of the sealing agent being wiped off.

Then, after the large-diameter fixing portion 4 is fitted to a predetermined position of the outer ring portion 2a, the large-diameter fixing portion 4 is tightened with a band 6. The large-diameter fixing part 4 is deformed by this tightening force,
Each space 9 is crushed and its volume is reduced. Therefore, the sealing agent enclosed in each space 9 is not directly connected to each passage 11.
Through the inner peripheral surface 4a of the fixed portion and the outer peripheral surface of the outer ring portion 2a (the outer peripheral surface of the mating member), that is, the so-called boot mounting surface. Then, the sealant is filled along the entire circumference while spreading along the boot mounting surface through the groove 16, and the gap on the boot mounting surface is closed by the sealant. In particular, the sealant is also reliably supplied to the boundary portion 13 between each bulge 8, 8, 8 and its surrounding cylindrical portion.

It should be noted that the above-mentioned embodiment is an example of a preferred embodiment of the present invention, but the present invention is not limited to this, and various modifications can be made without departing from the gist of the present invention. For example, although the case where the present invention is applied to the resin boot 1 has been described in this embodiment, it is needless to say that the present invention may be applied to, for example, a rubber boot. Further, in the present embodiment, the case where the present invention is applied to the large diameter fixing portion 4 side has been described, but it may be applied to the small diameter fixing portion 5 side.
Further, it is needless to say that it may be applied to both the large diameter fixing portion 4 side and the small diameter fixing portion 5 side.

In the boot 1 of this embodiment, the case of being attached to a tripod type constant velocity joint in which the inner peripheral surface of the large-diameter fixing portion 4 is provided with irregularities is mainly described, but the present invention is not particularly limited to this. However, even if the inner contour of the cross section of the large-diameter fixing portion 4 has another non-circular shape,
Further, the present invention can be applied to an elliptical shape and further a circular shape as shown in FIG.
In the boot 1 shown in FIG. 4, at least one hole 14 is bored in the large-diameter fixing portion 4 to form a space 9 for enclosing the sealing agent. The holes 14 are, for example, 4 at equal intervals in the circumferential direction.
It is provided in the place. Each hole 14 is closed by a plug 15. Further, the space 9 communicates with the inside of the large-diameter fixing portion 4 via the passage 11. Further, on the inner peripheral surface 4a of the large-diameter fixing portion 4, a groove 16 passing through the opening portion of the passage 11 is formed in order to facilitate the circumferential spreading of the sealant. The groove 16 is formed in an annular shape over the entire circumference of the large-diameter fixing portion 4. Therefore, when the large-diameter fixing portion 4 is tightened with the band 6, the sealant extruded into the groove 16 through the passages 11, ..., 11 by crushing the four spaces 9, 9, 9, 9 is The entire circumference of the boot mounting surface is satisfactorily filled through the groove 16. As the passage formed on the inner peripheral surface of the boot fixing portion, two sets of annular lips are formed in place of the groove 16 so as to project from the inner peripheral surface, and are constituted by an annular space between the pair of annular lips. The sealing agent may be introduced there. Further, it goes without saying that a groove or an annular lip that functions similarly to the groove 16 or the annular lip may be provided on the outer ring portion 2a side of the constant velocity joint 2.

In this embodiment, the sealant is sealed in the space 9 before the boot 1 is attached to the constant velocity joint 2, for example, when the boot is manufactured.
After mounting the boot 1, enclose a sealing agent in the space 9,
After that, the large-diameter fixing portion 4 may be tightened with the band 6 to crush the space 9. For example, after the boot 1 is attached to the constant velocity joint 2, the sealant is directly injected into the space 9 through the opening of the end surface of the fixing portion of the hole 12 or 14 and the sealant is sealed tightly. Is also good.
In this case, a step of injecting the liquid sealing agent into the space 9 is required for the boot mounting work, but it is mechanizable as compared with the time to apply it over the entire inner peripheral surface of the fixing portion 4, or an injecting jig is used. It is much easier to work with.
In addition, since the liquid sealant is reliably filled between the fixed portion 4 of the boot and the outer ring portion 2a which is the mating member, there is no possibility of poor sealing or obstruction of joint operation.

Further, in the boot 1 of this embodiment, the bulging portion 8
A hole 12 was drilled in the tip surface 8a of the to form a space 9,
The method of forming the space 9 is not limited to this.
For example, the space 9 may be formed by punching a hole from the outer peripheral surface side of the large-diameter fixing portion 4. In this case, the plug that closes the hole can be pressed by the band 6, and the plug can be prevented from coming off. Also,
Depending on conditions, it is possible to omit the plug and directly close the hole with the band 6.

Further, in the present embodiment, the passage 11 formed of a small diameter hole is adopted as a means for opening the space 9 to the inner peripheral surface side of the fixing portion, but the invention is not particularly limited to this, and for example, a slit or You may employ the passage 11 which consists of a break. In this case, when the space 9 is crushed and pressure is applied to the sealant, the slit opens to function as a passage and push out the sealant to the inner peripheral surface side of the fixed portion.

Further, in the present embodiment, the case where the present invention is applied to the boot 1 used for the constant velocity joint 2 has been described. However, the present invention can also be applied to steering boots for automobiles, and the bent portion and the stretchable portion. It may be applied to boots covering the above.

Further, as shown in FIG. 6, a space 17 for enclosing the sealant may be formed by forming a recess 17 in the inner peripheral surface 4a of the large-diameter fixing portion 4. In this case, the sealant is enclosed in the capsule 18 and accommodated in the space 9. Then, the sealant is supplied by destroying the capsule 18 while crushing the space 9 by the tightening force of the band (not shown). Capsule 18
The sealant that leaks from the large-diameter fixing portion 4 passes through the groove 16.
It spreads over the entire circumference of the inner peripheral surface 4a to seal the gap on the boot mounting surface. When the sealant is enclosed in the capsule 18, a hardening type sealant can be used as the sealant. Further, although the case where the liquid sealing agent is used has been described in the present embodiment, it is also possible to use the gel sealing agent. Furthermore, the groove 16 is not necessarily provided, and may be only the recess 17.

Further, in the boot 1 of the embodiment shown in FIG. 1, the bulging body 8 is integrally formed on the inner peripheral surface of the large-diameter fixing portion 4 so that the inner peripheral surface 4a conforms to the shape of the outer peripheral surface of the outer ring portion 2a. Although the case where the mount 19 is formed into a shape has been described, it may be applied to the case where the mount 19 which is separate from the large-diameter fixing portion 4 of the boot is used as shown in FIG. 7. In this case, the plurality of bulging portions 20 of the mount 19 are used to form the space 9 for enclosing the sealing agent, and further the space 9 is used to mount the inner surface 21 of the mount.
And the mount outer peripheral surface 22 are opened at the passages 11 respectively, and the mount outer peripheral surface 22 is tightened by the clamping means.
The sealing agent can be extruded to the inner surface 21 of the mount and the inner peripheral surface 21 of the mount at the same time, and the sealing agent is filled between the mount 19 and the boot fixing portion 4 and between the mount 19 and the mating member 2 to secure the sealing property. I am trying. Of course, in some cases, the passage 11 may be provided only on the inner side, and the sealant may be filled only between the mount 19 and the mating member 2. In the figure, reference numeral 23 is a hole that constitutes the space 9, and 24 is a plug that closes the hole 23.

[0030]

As is apparent from the above description, in the boot seal structure according to the first aspect of the present invention, the space that is open to the inner peripheral surface of the fixing portion that contacts the mating member and that can be crushed in the radial direction. Since the liquid sealant is enclosed in the space, if the space is crushed by some means after mounting the boot, the sealant is pushed out and filled between the inner peripheral surface of the fixed portion of the boot and the outer peripheral surface of the mating member. be able to. Therefore, the work of applying the sealant to the boot mounting surface can be omitted, and the workability can be improved. Moreover, since the sealant is filled on the boot mounting surface between the boot and the mating member after the boot is attached, the sealant is not wiped off when the boot is attached unlike the conventional case, and the sealant is reliably filled. Therefore, the sealing property can be improved.

According to the second aspect of the present invention, since the sealant pushed out toward the inner peripheral surface of the fixing portion due to the crushing of the space is spread in the inner peripheral direction through the passage, further in combination with the capillary phenomenon, the boot is produced. It is possible to surely fill the space between the fixed portion and the mating member over the entire circumference, and improve the sealing function.

According to the third aspect of the present invention, the sealant enclosed in the space is attached to the inner peripheral surface of the fixing part and the outer periphery of the mating member only by mounting the fixing part of the boot on the mating member and then tightening the clamp means. It can be extruded and filled between the surfaces. For this reason, the work of assembling the boots is extremely easy and time-consuming, and the sealing property can be secured.

[Brief description of drawings]

FIG. 1 is a central longitudinal sectional view showing an example of a boot in which a boot seal structure of the present invention is implemented.

FIG. 2 is a side view of the boot seen from the direction of arrow II in FIG.

FIG. 3 is an enlarged cross-sectional view of a fixing portion of the boot shown in FIG.

FIG. 4 is a side view of a boot showing another embodiment of the present invention.

5 is an enlarged cross-sectional view of a fixing portion of the boot of FIG.

FIG. 6 is a cross-sectional view showing, in an enlarged manner, only the vicinity of a boot fixing portion according to still another embodiment of the present invention.

FIG. 7 is a side view of a boot and a mount showing an embodiment when the seal structure of the present invention is applied to a boot assembled through a mount.

[Explanation of symbols]

 1 boot 2 constant velocity joint (counterpart member) 4 large diameter fixed part 6 band (clamping means) 9 space

Claims (3)

[Claims] 1. A boot having a fixing portion attached to the outer peripheral surface of a mating member at both ends of the bellows portion, wherein at least one of the fixing portions is opened to the inner peripheral surface side in contact with the mating member and is radially formed. A boot seal structure, wherein a crushable space is provided and a liquid sealing agent is enclosed in the space. 2. The boot seal structure according to claim 1, wherein at least one circumferential passage communicating with the space is provided on an inner peripheral surface of the fixing portion. 3. The space is crushed by tightening clamp means for attaching the fixing portion to the counterpart member,
The boot seal structure according to claim 1 or 2, wherein the sealed liquid sealant is filled between the inner peripheral surface of the fixed portion and the outer peripheral surface of the mating member.