JPH10153113A - Flexible tube for exhaust system of automobile and its manufacture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To assemble a bellows protecting blade without deteriorating flexibility of bellows and prevent excessive extention of the bellows in a flexible tube for an exhaust system of an automobile which eliminates relative displacement of a first exhaust pipe mounted on an engine side and a second exhaust pipe mounted on a muffler side. SOLUTION: A blade 1 has one end fixed to a front end collar 5 at its fixation part 8a, and the other end slid with a rear end collar 4 arranged inside, and fixed to a stopper collar 2 arranged outside at its fixation part 8c. An axial stopper clearance C is formed between the rear end collar 4 and the stopper collar 2 in a loadless state without input to cause deformation of bellows 3.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flexible tube for an automobile exhaust system which absorbs a relative displacement between a first exhaust pipe attached to an engine side of an exhaust system for a vehicle and a second exhaust pipe attached to a muffler side. Belongs to.

[0002]

2. Description of the Related Art Conventionally, as a flexible tube for an automobile exhaust system, for example, one shown in FIG. 4 is known.

[0003] This is because, for example, a SUS having a diameter of 0.4 mm is provided on the outer periphery of a flexible bellows 3 formed by processing a pipe-like tube into a bellows shape.
A front-end collar 5 and a rear-end collar 4 each of which is covered with a cylindrical blade 1 knitted with a wire, and a bowl-shaped bottom is punched with a circular hole at both ends of the blade 1, and these three members are spot-welded. Uses a fixed flexible tube for automotive exhaust systems.

[0004]

However, in the above-mentioned conventional flexible tube for an automobile exhaust system,
Since the blade 1 is fixed to both ends of the bellows 3,
There is a problem that flexibility, which is a characteristic of the flexible tube, is impaired by the tension of the blade 1.

An object of the present invention is to provide a flexible tube for an automobile exhaust system which absorbs a relative displacement between a first exhaust pipe attached to an engine of an automobile exhaust system and a second exhaust pipe attached to a muffler side. It is another object of the present invention to provide a flexible tube for an automobile exhaust system in which a blade for protecting the bellows can be incorporated without impairing the flexibility of the bellows, and at the same time, the bellows can be prevented from being extended.

[0006]

[Means for Solving the Problems]

(Solution 1) In order to achieve the above object, in the invention according to claim 1, a bellows whose both ends are connected to a first exhaust pipe and a second exhaust pipe, and a cylindrical shape that covers an outer periphery of the bellows are formed. In a flexible tube for an automobile exhaust system including a blade and a front end collar and a rear end collar fixed to both ends of the bellows, the blade has one end fixed to the front end collar, and the other end fixed. It is slidable with respect to the rear end collar arranged inside, fixed to the stopper collar arranged outside, and between the rear end collar and the stopper collar under no load with no input to deform the bellows. It is characterized in that an axial stopper-clearance is interposed.

(Solution means 2) In the invention according to claim 2,
2. The flexible tube for an automobile exhaust system according to claim 1, wherein the blade extends to an inner surface of the extension displacement restricting portion of the stopper collar which contacts the extension displacement restricting portion of the rear end collar.

(Solution 3) In order to achieve the above object, in the invention according to claim 3, a first step of fixing one end of the blade to the front end collar, and inserting a bellows into the inner peripheral surface of the front end collar. A second step of fixing one end of the bellows to the front end collar and fixing the other end to the rear end collar;
A third step of compressing the bellows to push the rear end collar into the blade, inserting a straight tubular stopper collar around the other end of the blade in this state, and fixing the stopper collar to the blade; Taper processing to narrow the outer part of the stopper collar in the pipe axis direction, release the force that has compressed and reduced the bellows, and increase the axial stopper clearance set between the rear end collar and the narrowed stopper collar. And a fourth step of intervening.

[0009]

Embodiments of the present invention will be described below with reference to the drawings.

(Embodiment 1) First, the configuration will be described.

The first embodiment corresponds to the first and second aspects of the present invention.

FIG. 1 is a half sectional view of a flexible tube for an automobile exhaust system according to Embodiment 1 in an unloaded state.

In FIG. 1, 1 is a blade, 2 is a stopper collar, 3 is a bellows, 4 is a rear end collar, 5 is a front end collar, 6 is a first exhaust pipe, 7 is a second exhaust pipe, 8a, 8
b, 8c and 8e are fixed parts.

The bellows 3 is made flexible by processing a pipe into a bellows shape, and both ends are connected to a first exhaust pipe 6 and a second exhaust pipe 7.

The blade 1 is made of, for example, a braided SUS wire having a diameter of about 0.4 mm, and is formed in a tubular shape to cover the outer periphery of the bellows 3.

The front end collar 5 and the rear end collar 4 are bowl-shaped and have a bottom punched out by a circular hole.
Are fixed (fixed portions 8a, 8e) to both end portions by spot welding or the like, respectively.

The stopper collar 2 includes a rear end collar 4
It is a color newly added to the side.

The blade 1 has a front end collar 5 at one end.
(Fixed portion 8b), the other end of which is slidable with respect to the rear end collar 4 disposed inside, and fixed to the stopper collar 2 disposed outside (fixed portion 8c).
Is done. The outer peripheral surface of the cylinder of the rear end collar 4 and the inner surface of the cylinder of the blade 1 serve as sliding surfaces, and slide according to the direction of displacement input while lightly contacting each other.

Then, as shown in FIG. 1, an axial stopper clearance C is interposed between the rear end collar 4 and the stopper collar 2 in a no-load state where there is no input to deform the bellows 3.

Further, the blade 1 has a rear end collar 4.
The stopper collar 2 extends to the inner surface of the extension regulating portion 2a of the stopper collar 2 which is in contact with the extension regulating portion 4a.

Next, the operation will be described.

[Displacement Absorbing Action] When a relative displacement occurs between the first exhaust pipe 1 and the second exhaust pipe 2 due to engine vibration, vehicle body vibration, or the like, the relative displacement is absorbed by deformation of the bellows 3. .

What is important in this displacement absorbing action is that the bellows 3 is deformed in accordance with the relative displacement between the exhaust pipes 1 and 2, and for this purpose, the flexibility of the bellows 3 is maintained.

On the other hand, the blade 1 for protecting the bellows 3 has one end fixed to the front end collar 5 and the other end slidable with respect to the rear end collar 4 disposed inside. Therefore, at the time of the displacement absorbing action, the outer peripheral surface of the cylinder of the rear end collar 4 and the inner surface of the cylinder of the blade 1 serve as sliding surfaces. 1 is bellows 3
The flexibility of the bellows alone can be maintained as it is without impairing the flexibility of the bellows.

[Elongation Displacement Restriction Action] When a force that causes an excessive elongation displacement acts on the bellows 3, the bellows 3 may be plastically deformed or damaged unless the maximum amount of extension displacement of the bellows 3 is regulated. In the conventional structure for fixing both ends of the blade, the amount of elongation deformation of the blade itself is limited, so that the blade deformation limit restricts excessive elongation displacement of the bellows 3.

On the other hand, in the present embodiment, since the other end of the blade 1 is slidable, it is necessary to add a separate displacement restricting means. Therefore, the stopper collar 2 is used as a functional component that fixes the other end of the blade 1 and regulates the extension displacement of the bellows 3.

Therefore, when a force causing an excessive extension displacement acts on the bellows 3, the extension regulating portion 4 a of the rear end collar 4 comes into contact with the extension regulating portion 2 a of the stopper collar 2 as shown in FIG. The maximum amount of elongation displacement is regulated.

[Color Hammering Suppressing Action] When a vibrating force that repeats an extension displacement and a contraction displacement acts on the bellows 3,
When the extension restricting portion 4a of the rear end collar 4 and the extension restricting portion 2a of the stopper collar 2 are in direct contact, a rattling sound is generated due to collision between the plate members.

On the other hand, the blade 1 is
As shown in FIG. 2, by adopting a configuration in which the extension restricting portion 4a of the stopper collar 2 is extended to the inner surface of the extension restricting portion 2a in contact therewith, between the extension restricting portions 4a and 2a, as shown in FIG. Is interposed, and the blade 1 woven with the thin wire acts as a cushioning material, thereby preventing rattling.

Next, the effects will be described.

(1) One end of the blade 1 is fixed to the front end collar 5 (fixing portion 8b), and the other end is slidable with respect to the rear end collar 4 arranged inside, and arranged outside. Fixed to the stopper collar 2 (fixed part 8c)
Then, with no load to deform the bellows 3,
Since a stopper C in the axial direction is interposed between the rear end collar 4 and the stopper collar 2, the bellows 3
For protecting bellows without compromising flexibility
And a flexible tube for an automobile exhaust system that can prevent the bellows 3 from being stretched out can be provided.

(2) Extend the blade 1 to the extension restricting portion 2 of the stopper collar 2 with which the extension restricting portion 4a of the rear end collar 4 contacts.
Since the blade 1 is extended to the inner surface of a, the blade 1 serves as a cushioning material against a vibrational input, and generation of a rattling sound can be prevented.

(Embodiment 2) Embodiment 2 is a third embodiment.
It corresponds to the described invention.

FIG. 3 is an explanatory view showing an outline of a procedure of a method of manufacturing a flexible tube for an automobile exhaust system according to a third embodiment of the present invention.

The flexible tube for an automobile exhaust system is
The first step shown in FIG. 3A, the second step shown in FIG. 3B, the third step shown in FIG. 3C, and the fourth step shown in FIG. Manufactured after passing through.

The first step is, as shown in FIG. 3A, a step of fixing one end of the blade 1 to the front end collar 5 by spot welding (fixing portion 8b).

In the second step, the bellows 3 is inserted into the inner peripheral surface of the front end collar 5 as shown in FIG.
Is fixed to the front end collar 5 (fixed portion 8a) and the other end is fixed to the rear end collar 4 (fixed portion 8e).

In the third step, as shown in FIG. 3 (c), the bellows 3 is compressed and the rear end collar 4 is pushed into the blade 1, and in this state, the rear end collar 4 is placed directly on the outer periphery of the other end of the blade 1. In this step, the tubular stopper collar 2 is inserted and fixed to the blade 1 by spot welding (fixing portion 8c).

In the fourth step, as shown in FIG. 3 (d), the outer portion of the straight tubular stopper collar 2 is tapered so as to be narrowed in the axial direction of the tube, and the force that has compressed the bellows 3 is released. A step of interposing an axial stopper-clearance C set between the rear end collar 4 and the narrowed stopper collar 2.

In manufacturing this flexible tube for an automobile exhaust system, a point that differs greatly from the conventional one is that one end of the blade 1 is fixed to the front end collar 5 and the other end is fixed to the stopper collar 2. When these are fixed by spot welding, it is necessary to secure a space for inserting a welding arm.

On the other hand, according to the manufacturing method described in the third embodiment, in the first step shown in FIG. By fixing one end of the blade 1 by spot welding, a space for inserting a welding arm is secured.
In the third step shown in (c), a straight tubular stopper collar 2 is inserted into the outer periphery of the other end of the blade 1 while the rear end collar 4 is pushed into the blade 1 by compressing the bellows 3 and 1 is secured by spot welding to secure a space for inserting a welding arm.

Accordingly, since both ends of the blade 1 can be fixed by spot welding, the blade 1 can be automated on a production line using a welding robot or the like, and the production efficiency is increased.

[0043]

According to the first aspect of the present invention, there is provided a bellows having both ends connected to the first exhaust pipe and the second exhaust pipe, a cylindrical blade covering the outer periphery of the bellows, and a bellows. A front end collar and a rear end collar fixed to both ends of a flexible tube for an automobile exhaust system, wherein one end of the flexible tube is fixed to the front end collar, and the other end is disposed inside. It is slidable to the end collar, fixed to the stopper collar arranged on the outside, and there is no load to deform the bellows, and the axial stopper-clearance between the rear end collar and the stopper collar is set. Since it is interposed, a blade for protecting the bellows can be incorporated without impairing the flexibility of the bellows, and at the same time, the bellows can be prevented from being extended. Effect is obtained that it is possible to provide a table tube.

According to the second aspect of the present invention, a first aspect is provided.
In the flexible tube for automotive exhaust system described in
Since the blade extends to the inner surface of the extension displacement restricting portion of the stopper collar where the extension displacement restricting portion of the rear end collar contacts, in addition to the above effects, the blade becomes a cushioning material against vibrational input, and the occurrence of rattling noise is reduced. Can be prevented.

According to the third aspect of the present invention, a first step of fixing one end of the blade to the front end collar, inserting a bellows into the inner peripheral surface of the front end collar, and connecting one end of the bellows to the front end. A second step of fixing to the collar and fixing the other end to the rear end collar, and pressing and shrinking the bellows to push the rear end collar into the blade; The third step of inserting the stopper collar and fixing it to the blade, and tapering the outer part of the straight tubular stopper collar in the tube axis direction to release the force that has pressed and shrunk the bellows, and the rear end collar And a fourth step of interposing an axial stopper-clearance set between the stopper collar and the narrowed stopper collar, without impairing the flexibility of the bellows. There is an advantage that it is possible to provide a manufacturing method for high production efficiency automotive exhaust system flexible tubing that fully extended prevention of the bellows is ensured it is possible to incorporate a blade for Rose protection.

[Brief description of the drawings]

FIG. 1 is a half sectional view showing a flexible tube for an automobile exhaust system according to a first embodiment of the present invention.

FIG. 2 is a half sectional view showing a state in which a bellows extension displacement of a flexible tube for an automobile exhaust system according to Embodiment 1 of the present invention is restricted.

FIG. 3 is a process explanatory view illustrating a method for manufacturing a flexible tube for an automobile exhaust system according to a second embodiment of the present invention.

FIG. 4 is a half sectional view showing a conventional flexible tube for an automobile exhaust system.

[Explanation of symbols]

 Reference Signs List 1 blade 2 stopper collar 3 bellows 4 rear end collar 5 front end collar 6 first exhaust pipe 7 second exhaust pipe 8a, 8b, 8c, 8e fixing part

Claims (3)

[Claims] A bellows (3) having both ends connected to a first exhaust pipe (6) and a second exhaust pipe (7); and a blade (3) formed in a cylindrical shape to cover an outer periphery of the bellows (3). 1) and a front end collar (5) and a rear end collar (4) fixed to both ends of the bellows (3). A flexible tube for an automobile exhaust system, comprising: the blade (1); Is fixed to the front end collar (5), the other end is slidable with respect to the rear end collar (4) arranged inside, and fixed to the stopper collar (2) arranged outside. An automobile characterized in that an axial stopper-clearance (C) is interposed between a rear end collar (4) and a stopper collar (2) in a no-load state where there is no input to deform the bellows (3). Flexible tube for exhaust system. 2. The flexible tube for an automobile exhaust system according to claim 1, wherein the blade (1) is in contact with an extension displacement regulating portion (4a) of a rear end collar (4) to regulate extension displacement of a stopper collar (2). A flexible tube for an automobile exhaust system, wherein the flexible tube extends to the inner surface of the portion (2a). 3. A first step of fixing one end of the blade (1) to the front end collar (5), and inserting a bellows (3) into the inner peripheral surface of the front end collar (5);
Fix one end of the bellows (3) to the front collar (5),
A second step of fixing the other end to the rear end collar (4), and pressing and shrinking the bellows (3) to push the rear end collar (4) into the blade (1); A) inserting a straight tubular stopper collar (2) into the outer circumference of the other end of (2) and fixing it to the blade (1); A taper process is performed to narrow the bellows (3), the force that has been pressed and shrunk is released, and an axial stopper-clearance (C) set between the rear end collar (4) and the narrowed stopper collar (2). A) a fourth step of interposing), a method for manufacturing a flexible tube for an automobile exhaust system, characterized by comprising: