CN114017171A

CN114017171A - Exhaust pipe sealing structure

Info

Publication number: CN114017171A
Application number: CN202111246783.8A
Authority: CN
Inventors: 陈珏; 范建权; 吴金柱; 吴红亮; 王振红; 黄世宏
Original assignee: Dongfeng Commercial Vehicle Co Ltd
Current assignee: Dongfeng Commercial Vehicle Co Ltd
Priority date: 2021-10-26
Filing date: 2021-10-26
Publication date: 2022-02-08

Abstract

The invention discloses a sealing structure of an exhaust pipe. The sealing ring is arranged between a front exhaust manifold and a rear exhaust manifold, the joint of the rear exhaust manifold is of a tapered structure with gradually changed inner size and outer size, the joint of the front exhaust manifold is of a tapered structure with gradually changed inner size and outer size, and the joint of the front exhaust manifold is arranged in the rear exhaust manifold. When the front exhaust manifold and the rear exhaust manifold are heated to generate thermal deformation, relative movement occurs between the front exhaust manifold and the rear exhaust manifold, an axial gap between the front exhaust manifold and the rear exhaust manifold is reduced, the front exhaust manifold and the rear exhaust manifold move axially and mutually, and a radial gap is reduced. The invention effectively improves the sealing capability between the sections, improves the problem of air leakage between the sections and improves the product quality.

Description

Exhaust pipe sealing structure

Technical Field

The invention belongs to the technical field of engine exhaust systems, and particularly relates to an exhaust pipe sealing structure.

Background

In the existing medium and heavy diesel engines, the exhaust manifold is mostly of a segmented structure and is generally divided into two or three segments. When the engine works, if the sealing between the two exhaust manifolds is not good, the air leakage phenomenon can occur from the connection part of the two exhaust manifolds, surrounding parts are blackened, and the air leakage phenomenon is not accepted in sense when a user uses the engine. Usually, two exhaust manifolds are connected by a sliding sleeve mode, the front section extends into the middle section or the rear section, the front, middle and rear exhaust manifolds adopt a cylindrical structure, and the two sections are in clearance fit. Meanwhile, in order to reduce gas leakage, a ring groove is machined on the front section, a sealing ring is installed, the outer diameter of the sealing ring is larger than the inner diameter of the matched part of the middle-rear section exhaust manifold in a free state, and the sealing ring is in a compressed state in a working state and can prevent gas leakage.

In the prior art, after the exhaust manifold is installed, the radial fit clearance between the front section and the rear section of the exhaust manifold is basically fixed, and due to the small theoretical value of the clearance, the exhaust manifold may have assembly stress due to manufacturing factors;

after a certain working cycle of the engine, the performance of the sealing ring is reduced, but the radial fit clearance of the two exhaust manifolds is not changed, so that the sealing capability is insufficient, and the air leakage condition between the two sections occurs.

Disclosure of Invention

The present invention is directed to solve the above-mentioned drawbacks of the prior art, and to provide a sealing structure for an exhaust pipe.

The technical scheme adopted by the invention is as follows: the utility model provides an exhaust pipe seal structure, is including setting up the sealing ring between preceding exhaust manifold and back exhaust manifold, back exhaust manifold's joint is the toper structure of big end down gradual change, preceding exhaust manifold's joint is arranged in back exhaust manifold.

When the front exhaust manifold and the rear exhaust manifold are heated to generate thermal deformation, relative movement occurs between the front exhaust manifold and the rear exhaust manifold, an axial gap between the front exhaust manifold and the rear exhaust manifold is reduced, the front exhaust manifold and the rear exhaust manifold move axially and mutually, and a radial gap is reduced.

In a further preferred structure, the taper angle of the joint surface at the joint of the front exhaust manifold and the rear exhaust manifold is 3-20 °.

In a further preferred configuration, the diameter of the front exhaust manifold junction gradually increases in the insertion direction.

In a further preferable structure, the sealing ring is an open ring, the cross section of the sealing ring is trapezoidal, the trapezoidal angle is the same as the taper angle of the exhaust manifold, and the opening is of an L-shaped lap joint structure or an oblique notch structure.

In a further preferred configuration, the sealing ring comprises one or two.

In a further preferable structure, the width of the sealing ring is 1-3 mm.

In a further preferable structure, a gap is arranged between the front exhaust manifold and the rear exhaust manifold in the radial direction, and the gap is 0-0.5 mm.

An engine exhaust system comprises the exhaust pipe sealing structure.

The invention is applicable to sealing between two exhaust manifold segments, but not limited to two exhaust manifold segments.

The invention adopts a conical intersegment connecting structure and a trapezoidal sealing ring, and can reduce intersegment sealing clearance, reduce gas leakage and improve intersegment sealing capability when an engine works.

The invention effectively improves the sealing capability between the sections, improves the problem of air leakage between the sections and improves the product quality. The invention reduces the leakage rate between the exhaust manifold sections and improves the sealing capability; the appearance quality of parts near the exhaust manifold is improved, and complaints of users are reduced; the assembly stress of the exhaust manifold is reduced, and the durability of the exhaust manifold is improved.

Drawings

FIG. 1 is a schematic exhaust manifold connection;

FIG. 2 is a schematic cross-sectional view of a seal ring;

FIG. 3 is a schematic view of an embodiment of a seal ring overlapping structure;

FIG. 4 is a schematic view of a second embodiment of a lap joint structure of a sealing ring.

Wherein, 1-front exhaust manifold, 2-rear exhaust manifold and 3-sealing ring.

Detailed Description

The invention will be further described in detail with reference to the following drawings and specific examples, which are not intended to limit the invention, but are for clear understanding.

As shown in fig. 1-2, the present invention includes a sealing ring 3 disposed between a front exhaust manifold 1 and a rear exhaust manifold 2, the joint of the rear exhaust manifold 2 is a tapered structure with gradually changing inner size and outer size, the joint of the front exhaust manifold 1 is a tapered structure with gradually changing inner size and outer size, and the joint of the front exhaust manifold 1 is disposed in the rear exhaust manifold 2.

When the front exhaust manifold 1 and the rear exhaust manifold 2 are heated to generate thermal deformation, relative movement occurs between the front exhaust manifold 1 and the rear exhaust manifold 2, an axial gap between the front exhaust manifold 1 and the rear exhaust manifold 2 is reduced, the front exhaust manifold 1 and the rear exhaust manifold 2 move axially and mutually, and a radial gap is reduced.

The cone angle of the joint surface of the joint of the front exhaust manifold 1 and the rear exhaust manifold 2 is 3-20 degrees.

The diameter of the junction of the front exhaust manifold 1 gradually increases in the insertion direction.

The sealing ring 3 is an open ring, the section of the sealing ring is trapezoidal, the trapezoidal angle is the same as the taper angle of the exhaust manifold, and the opening is of an L-shaped lap joint structure or an oblique notch structure.

The sealing ring 3 includes one or two.

The width of the sealing ring 3 is 1-3 mm.

A gap is arranged between the front exhaust manifold 1 and the rear exhaust manifold 2 in the radial direction, and the gap is 0-0.5 mm.

An engine exhaust system comprises the exhaust pipe sealing structure.

The front exhaust manifold 1 and the rear exhaust manifold 2 are in clearance fit in the radial direction when connected, two sealing rings 3 are installed in the front exhaust manifold 1, the diameter of each sealing ring 3 is larger than the inner diameter of the rear exhaust manifold 2, as shown in fig. 1, after the sealing rings 3 are installed, the sealing rings 3 are in a compression state, and the sealing rings are tightly attached to the rear exhaust manifold 2 through tension force, so that gas leakage is prevented.

When the exhaust manifold is heated to generate thermal deformation, the front exhaust manifold 1 and the rear exhaust manifold 2 move relatively, the axial gap between the front exhaust manifold 1 and the rear exhaust manifold 2 is reduced, and the radial gap is further reduced due to the fact that the front exhaust manifold and the rear exhaust manifold move mutually in the axial direction, and the gas leakage amount is reduced.

The sealing ring 3 is 1-3 mm wide, the cross section of the sealing ring is trapezoidal, as shown in fig. 2, the angle of a trapezoidal inclined edge is consistent with that of the front exhaust manifold and that of the rear exhaust manifold, the elasticity of the sealing ring is large, and the radial single-edge gap of the exhaust manifold after matching is 0-0.5 mm, so that errors generated when the front exhaust manifold and the rear exhaust manifold are installed are made up, and assembly stress is eliminated.

The opening of the sealing ring 3 adopts a lap joint structure, and the opening is an L-shaped lap joint structure or an oblique notch structure, as shown in figures 3 and 4, the sealing effect in a cold state can be improved.

Those not described in detail in this specification are within the skill of the art.

Claims

1. An exhaust pipe sealing structure, including set up sealing ring (3) between preceding exhaust manifold (1) and back exhaust manifold (2), its characterized in that: the joint of the rear exhaust manifold (2) is of a tapered structure with gradually changed inner size and outer size, the joint of the front exhaust manifold (1) is of a tapered structure with gradually changed inner size and outer size, and the joint of the front exhaust manifold (1) is arranged in the rear exhaust manifold (2).

2. The exhaust pipe sealing structure according to claim 1, wherein: when the front exhaust manifold (1) and the rear exhaust manifold (2) are heated to generate thermal deformation, relative movement occurs between the front exhaust manifold (1) and the rear exhaust manifold (2), an axial gap between the front exhaust manifold (1) and the rear exhaust manifold (2) is reduced, the front exhaust manifold (1) and the rear exhaust manifold (2) move axially and mutually, and a radial gap is reduced.

3. The exhaust pipe sealing structure according to claim 1, wherein: the cone angle of a joint surface at the joint of the front exhaust manifold (1) and the rear exhaust manifold (2) is 3-20 degrees.

4. The exhaust pipe sealing structure according to claim 1, wherein: the diameter of the joint of the front exhaust manifold (1) is gradually increased along the insertion direction.

5. The exhaust pipe sealing structure according to claim 1, wherein: the sealing ring (3) is an open ring, the section of the sealing ring is trapezoidal, the trapezoidal angle is the same as the taper angle of the exhaust manifold, and the opening is of an L-shaped lap joint structure or an oblique notch structure.

6. An exhaust pipe sealing structure according to claim 1 or 5, wherein: the sealing ring (3) comprises one or two.

7. An exhaust pipe sealing structure according to claim 1 or 5, wherein: the width of the sealing ring (3) is 1-3 mm.

8. The exhaust pipe sealing structure according to claim 2, wherein: a gap is arranged between the front exhaust manifold (1) and the rear exhaust manifold (2) in the radial direction, and the gap is 0-0.5 mm.

9. An engine exhaust system characterized by: comprising the exhaust pipe sealing structure of claim 1.

10. An engine exhaust system according to claim 9, wherein: when the front exhaust manifold (1) and the rear exhaust manifold (2) are heated to generate thermal deformation, relative movement occurs between the front exhaust manifold (1) and the rear exhaust manifold (2), an axial gap between the front exhaust manifold (1) and the rear exhaust manifold (2) is reduced, the front exhaust manifold (1) and the rear exhaust manifold (2) move axially and mutually, and a radial gap is reduced.