JPH1038083A - Boot for fitted part - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce manufacturing cost of a cylinder material and a shaft material by improving an installing property, simplifying structure of installing parts on the cylinder material and the shaft material and shortening processing time of these installing parts. SOLUTION: Diametrical direction clad parts 30, 31 to fasten outer peripheral surfaces 33, 34 of installing parts 24, 25 on which end parts 27, 28 of a boot 20 are fit and axial direction clad parts 42, 43 to adsorb contact surfaces 36, 37 along the diametrical direction equipped on the aforementioned installing parts 24, 25 are equipped on the end parts 27, 28 of the boot 20, and free length between the end parts 27, 28 of the boot 20 is set larger than dimension of the maximum clearance between the installing parts 24, 25.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cylindrical member which can be extended and contracted, one end of which is fitted to the outer periphery of an opening end of a cylindrical member, and which is slidably fitted to the cylindrical member. The other end is fitted to the outer periphery of the shaft member whose projection length from the open end of the cylindrical member changes due to the moving operation, so that dust or the like is prevented from entering between the cylindrical member and the shaft member. The present invention relates to a part boot.

[0002]

2. Description of the Related Art FIG. 5 shows a cross section of a main part of a disk brake device 1 for a vehicle. The disc brake device 1 presses a pair of brake pads 3 arranged so as to sandwich a disc rotor 2 that rotates integrally with a wheel against the disc rotor 2 by a pressing force of a piston provided in a cylinder portion of a caliper body 4. To generate braking force.

The caliper body 4 includes a slide pin 6
And is supported by the support 5 so as to be slidable in the axial direction of the disk rotor 2. In order to maintain smooth sliding of the caliper body 4 according to the brake operation, it is important to prevent dust and raindrops from entering between the support 5 and the slide pin 6.

Therefore, as a measure for preventing dust or raindrops from entering between the support 5 and the slide pin 6, a boot 8 is usually mounted as shown in FIG. These boots 8
Is a molded article made of an elastic material such as synthetic rubber excellent in heat resistance and oil resistance. As shown in FIG. 6, the slide pin 6 is formed in an expandable and contractible cylindrical shape, one end of which is fitted on the outer periphery of the open end of the support 5, and the outer periphery of the slide pin 6 protruding from the open end of the support 5. Is fitted at the other end.

[0005] More specifically, in the case of the boot 8 described above, both end portions are provided on the inner diameter side with a convex portion 9 having a rectangular cross section.
10 is formed over the entire circumference. At the positions corresponding to the outer peripheral portions of the support 5 and the slide pin 6, the locking grooves 1 into which the convex portions 9 and 10 fit tightly and closely.
2, 13 are provided around.

Accordingly, the boot 8 is firstly elastically deformed so that the projections 9 and 10 at both ends are elastically larger than the outer diameters of the support 5 and the slide pin 6 to which they are fitted. The protrusions 9 and 10 are engaged with the corresponding supports 5 and the slide pins 6, and then are slid over the supports 5 and the slide pins 6 to engage the corresponding locking grooves 12 and 13 with the corresponding locking grooves 12 and 13. In this state, each end is fixed to the outer periphery of the support 5 and the slide pin 6, respectively.

FIG. 6 shows the support 5 having a large diameter.
As shown in (2), if necessary, a fastening ring 15 is mounted on the projection 9 to improve the fixing strength.

[0008]

However, in the case of the boot 8 described above, the ends are supported by the support 5 and the slide pin 6.
In order to engage with the locking grooves 12 and 13 of the
10 has to be forcibly expanded by the steps L ₁ , L _{2 in} front of the locking grooves 12, 13, so that there is a problem that the mounting work is troublesome.

Further, the above-mentioned projections 9, 10 of the boot 8 are provided.
As shown in FIG. 7, the locking grooves 12 and 13 are formed when the cutting tool is not fed in both the Y-axis direction shown by the arrow (A) and the X-axis direction shown by the arrow (B). Therefore, there has been a problem that the processing time is lengthened and the cost is increased.

Accordingly, an object of the present invention is to solve the above-mentioned problems, and when the end of the boot is fitted to the outer periphery of the cylindrical member or the shaft member, the time required for expanding the diameter of the ring at the end of the boot is reduced. It is almost useless and can be easily attached. In addition, the structure of the attachment portion provided on the outer periphery of the cylindrical member or shaft member for fixing the end of the boot is simple, and the processing time of the attachment portion is reduced. Accordingly, an object of the present invention is to provide a boot for a fitting portion which can reduce the manufacturing cost of the cylindrical member and the shaft member.

[0011]

According to a first aspect of the present invention, there is provided a boot for a fitting portion which is formed in a tubular shape which can be extended and contracted, and one end of which is fitted around the open end of the tubular member. The other end is fitted to the outer periphery of a shaft member, which is slidably fitted to the cylindrical member and whose projection length changes from an open end of the cylindrical member by a sliding operation, and is attached to the cylindrical member. Boot for preventing dust and the like from entering between the shaft member and the shaft member, and at an end of the boot for the fitting portion to be fitted to at least one mounting portion of the cylindrical member and the shaft member. Is
A radial crimping portion that radially tightens the outer peripheral surface of the mounting portion, and a closed chamber is defined between the contact surface by abutting a contact surface along the radial direction provided on the mounting portion. An axial crimping portion that generates an adsorbing force on the contact surface by reducing the volume of the closed chamber when pressed against the contact surface, and the free length between the ends of the boot for the fitting portion is The elasticity when the ends of the boots are compressed in the axial direction by setting them to be larger than the maximum distance between the mounting portions on the cylindrical member and the shaft member on which the ends of these boots for fitting are fitted. In a compressed state, both ends of the boot are fitted to the mounting portion on the tubular member and the shaft member so that the restoring force acts as a force for pressing the axial crimping portion against the contact surface of the mounting portion. It is assumed that.

[0012] In the boot for a fitting portion having the above-described structure, the end portion of the boot fitted to the mounting portion of at least one of the tubular member and the shaft member has the radially crimping portion closely contacting the outer peripheral surface of the mounting portion. By doing so and the axial crimping portion being in close contact with the contact surface of the mounting portion, a double sealing structure is formed in the mounting portion, and the sealing performance between the boot end and the mounting portion is improved.

The axial crimping portion provided at the end of the boot is a fixing means for adsorbing the contact surface of the mounting portion of the cylindrical member or the shaft member to restrict the movement of the end of the boot in the axial direction. Function. Therefore, at least one of the mounting portions of the cylindrical member and the shaft member can have a simple step structure in which the abutting surface rises in the back of the cylindrical portion to which the radial pressing portion is fitted.

Since the mounting portion can have a simple stepped structure, when the end of the boot is fitted to the mounting portion of the tubular member or the shaft member, the diameter is increased so as to get over the conventional groove wall. Becomes unnecessary.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the illustrated embodiments. FIGS. 1 and 2 show a first embodiment of a boot for a fitting portion according to the present invention. FIG. 1 shows a boot for a fitting portion of the first embodiment (hereinafter sometimes simply referred to as a boot). FIG. 2 is a part of a longitudinal sectional view of the boot 20 when the boot 20 is extended.

The boot 20 of the first embodiment has a slide pin 21 fixed to the caliper body 4 at both ends in a pin slide type disc brake device.
And the support 22 to prevent dust and raindrops from entering between the slide pin 21 and the support 22. Note that, in FIG.
5 shows an upper half range from the center line 23 of FIG.

The boot 20 is formed in a bellows tube which can be extended and contracted with an elastic material such as synthetic rubber which is excellent in heat resistance and oil resistance, and one end of the boot 20 is fitted around the open end of the support 22. The other end is fitted to the outer periphery of a slide pin 21 which is slidably fitted to the support pin 22 and whose projection length from the open end of the support 22 changes by a sliding operation.

A radial crimping portion 3 is attached to each end 27, 28 of the fitting boot 20 to be fitted to the mounting portion 24, 25 on the support 22 or the slide pin 21.
0, 31 and axial crimping portions 42, 43 are provided.

Here, the radial crimping portions 30 and 31 are annular portions protruding over the entire circumference on the inner diameter side.
The outer peripheral surfaces 33, 34 of the 4, 25 are fastened in the radial direction. The axial crimping portions 42 and 43 are attached to the mounting portions 24 and 25, respectively.
By contacting the contact surfaces 36 and 37 along the radial direction provided in the closed chamber 3 between the contact surfaces 36 and 37.
9 and 40 are elastic protrusions that generate an attraction force on the contact surfaces 36 and 37 by being reduced by the volume of the closed chambers 39 and 40 when pressed by the contact surfaces 36 and 37. . The axial crimping portions 42 and 43 are also formed all around the ring.

FIG. 2 shows a state in which the brake pad is worn to the limit and the slide pin 21 is protruded to the maximum (that is, the slide pad 21 is in the maximum).
Mounting portion 24 on support 22 and slide pin 21,
25 in which the distance between each other is maximized). In FIG. 2, the boot 20 indicated by a two-dot chain line is shown.
Indicates a free length state. That is, the free length between the ends 27 and 28 of the boot 20 is set to be larger by an appropriate amount L than the maximum distance between the mounting portions 24 and 25 on the support 22 and the slide pin 21. Then, the elastic restoring force when the space between the ends 27 and 28 of the boot 20 is compressed in the axial direction is applied to the axial compression parts 42 and 43 by the mounting part 2.
In a compressed state, both ends 27 and 28 of the boot are attached to the support 22 and the mounting portion 24 on the slide pin 21 so as to act as a pressing force on the contact surfaces 36 and 37 of the support pins 4 and 25.
25.

In the boot 20 of the first embodiment described above, the end portions 27, 28 of the boot 20 fitted to the mounting portions 24, 25 of the support 22 and the slide pin 21 are fitted with the radial pressing portions 30, 31, respectively. The attachment portions 24, 25 are closely attached to the outer peripheral surfaces 33, 34, and the axial crimping portions 42, 43 are attached to the contact surfaces 36, 37 of the attachment portions 24, 25. A heavy sealing structure is formed.
Therefore, each end 27, 28 of the boot 20 and the mounting portion 24,
The seal performance between the support 22 and the slide pin 21 can be improved, and the prevention of intrusion of dust and the like between the support 22 and the slide pin 21 can be achieved at a higher level.

The axial crimping portions 42 and 43 provided at the ends 27 and 28 of the boot 20 are attracted to the contact surfaces 36 and 37 of the supports 22 and the mounting portions 24 and 25 of the slide pin 21, respectively. It functions as fixing means for restricting the movement of the ends 27 and 28 of the boot 20 in the axial direction.

Accordingly, the support 22 and the slide pin 21
As shown in the figure, the mounting portions 24 and 25 are provided with the abutment surfaces 36 and 25 at the back of a cylindrical portion on which the radial crimping portions 30 and 31 are fitted.
37 can be a simple step structure that stood up,
Compared with the conventional case in which the groove structure is required, when the mounting portions 24 and 25 are formed by cutting, the cutting tool is, for example, as shown by an arrow (c) in FIG. The feed operation may be performed only in the axial direction of the above, and the manufacturing time of the support 22 and the slide pin 21 can be reduced by shortening the processing time of the mounting portions 24 and 25.

Further, since the mounting portions 24 and 25 can have a simple step structure, the ends 27 and 28 of the boot 20 can be formed.
Mounting portions 24 and 25 for the support 22 and the slide pin 21
In the case of fitting into the boot 20, it is not necessary to increase the diameter to get over the conventional groove wall.
Efforts such as expanding the diameter of the ring of No. 8 are almost unnecessary, the mounting can be easily performed, and the effect of greatly improving the mounting performance is also exhibited.

In the first embodiment, the axial crimping portions 42 and 43 are formed in a single annular shape, and the closed chambers 39 and 40 are formed by the cooperation of the axial crimping portion and the radial crimping portion. It was configured to define. However, like the axial crimping portion 42 shown in FIG. 4, the axial crimping portion may be configured by two annular elastic projecting pieces 45, and the closed chamber 39 may be defined by the axial crimping portion 42 alone. .

In the above-described first embodiment, the radial crimping portions 42 and 43 and the axial crimping portions 30 and 31 are provided at both ends of the fitting portion boot. It is needless to say that the structure can be changed to a structure in which a known structure is adopted on one end side and a radial crimping section and an axial crimping section are provided only on the other end side.

Further, the environment in which the boot for the fitting portion of the present invention is used is not limited to the space between the support 22 and the slide pin 21 of the disk brake device shown in the above-described embodiment, but the space between the cylinder and the piston. And a similar mechanism in a drum brake device.

The support 22 is fitted to a cylindrical member having one end opened, and the slide pin 21 is slidably fitted to the cylindrical member, and the length of projection of the cylindrical member from the open end is changed by sliding operation. The fitting boots of the present invention can be applied to various mechanisms that require prevention of intrusion of dust and the like between the tubular member and the fitted shaft member. it can.

[0029]

According to the boot for the fitting portion of the present invention, the end portion of the boot fitted to the mounting portion of the cylindrical member or the shaft member has the radially crimped portion in close contact with the outer peripheral surface of the mounting portion. , And the axial crimping part is in close contact with the contact surface of the mounting part,
A double sealing structure is formed on the mounting portion. Therefore, the sealing performance between the end portion of the boot and the mounting portion is improved, and the prevention of intrusion of dust and the like between the tubular member and the shaft member can be achieved at a higher level. Further, the axial crimping portion provided at the end of the boot adsorbs to the contact surface of the mounting portion of the tubular member or the shaft member, and functions as a fixing means for restricting the movement of the end of the boot in the axial direction. Therefore, the mounting portion of the cylindrical member or the shaft member can have a simple step structure in which the abutting surface rises in the back of the cylindrical portion on which the radial pressure-bonding portion is fitted. Compared with the conventional art, when forming the mounting portion by cutting, the cutting tool may be fed only in the axial direction of, for example, a cylindrical member or a shaft member. And the manufacturing cost of the shaft member can be reduced. In addition, since the mounting portion can have a simple step structure, when the end portion of the boot is fitted to the mounting portion of the cylindrical member or the shaft member, it is not necessary to expand the diameter to get over the conventional groove wall. As a result, there is almost no need for labor such as expanding the diameter of the ring at the end of the boot, the mounting can be easily performed, and the mounting performance is greatly improved.

[Brief description of the drawings]

FIG. 1 is a part of a longitudinal sectional view of a first embodiment of a boot for a fitting portion according to the present invention.

FIG. 2 is a part of a longitudinal sectional view showing a state where a boot for a fitting portion according to the first embodiment of the present invention is extended.

FIG. 3 is an explanatory diagram of an operation effect when the boot for a fitting portion according to the first embodiment of the present invention is used.

FIG. 4 is a longitudinal sectional view of a main part of a second embodiment of a boot for a fitting part according to the present invention.

FIG. 5 is a cross-sectional view of a main part of a disk brake device for a vehicle using a conventional boot.

FIG. 6 is an enlarged view of a main part of FIG. 5;

FIG. 7 is an explanatory diagram of a problem when a conventional boot is used.

[Explanation of symbols]

 Reference Signs List 20 boot for fitting portion 21 slide pin (shaft member) 22 support (tubular member) 24, 25 mounting portion 27, 28 end 30, 31 radial crimping portion 33, 34 outer peripheral surface 36, 37 contact surface 39, 40 Sealed chamber 42, 43 Axial crimping part 45 Elastic protruding piece (Axial crimping part)

Claims (1)

[Claims] 1. A tubular member which is formed to be expandable and contractible, one end of which is fitted to the outer periphery of an opening end of the tubular member, and which is slidably fitted to the tubular member and which is slidable by a sliding operation. The other end is fitted to the outer periphery of a shaft member having a protruding length that changes from the opening end of the fitting member, and the fitting member boot prevents dust and the like from entering between the cylindrical member and the shaft member. An end portion of the boot for the fitting portion to be fitted to at least one of the mounting portions of the cylindrical member and the shaft member is provided with a radial crimping portion for radially fastening an outer peripheral surface of the mounting portion, and the mounting portion. By contacting the contact surface along the radial direction, a closed chamber is defined between the contact surface and the contact surface, and when the contact surface is further pressed, the volume of the closed chamber is reduced, so that suction is performed on the contact surface. Equipped with an axial crimping part that generates force, and free between the ends of the boot for fitting part Is set to be larger than the maximum distance between the mounting portions on the cylindrical member and the shaft member on which the ends of the boots for the fitting portion are fitted, and when the ends between the boots are compressed in the axial direction. In a compressed state, both ends of the boot are fitted to the mounting portions on the tubular member and the shaft member so that the elastic restoring force acts as a force for pressing the axial crimping portion against the contact surface of the mounting portion. Characteristic boot for fitting part.