CN210013746U

CN210013746U - Exhaust manifold sealing structure of medium and heavy diesel engine

Info

Publication number: CN210013746U
Application number: CN201920986964.6U
Authority: CN
Inventors: 赖钧明; 吴世友; 孟繁臣; 刘文剑; 李强
Original assignee: FAW Jiefang Automotive Co Ltd
Current assignee: FAW Jiefang Automotive Co Ltd
Priority date: 2019-06-28
Filing date: 2019-06-28
Publication date: 2020-02-04
Anticipated expiration: 2029-06-28

Abstract

The utility model relates to an exhaust manifold, specific well heavy diesel engine exhaust manifold seal structure that says so belongs to well heavy diesel engine exhaust system technical field. The exhaust manifold comprises an exhaust manifold front section, an exhaust manifold middle section and an exhaust manifold rear section, wherein a front sealing structure is arranged at the joint of the exhaust manifold middle section and the exhaust manifold front section, and a rear sealing structure is arranged at the joint of the exhaust manifold rear section and the exhaust manifold front section; the front sealing structure comprises a first step hole, a second step hole and a third step hole which are arranged on the inner surface of the end part of the middle section of the exhaust manifold, and a first step, a second step and a third step which are arranged on the outer surface of the end part of the front section of the exhaust manifold, wherein the first step hole, the second step hole and the third step hole are in clearance fit connection with the first step, the second step and the third step respectively. The utility model discloses can form more reliable sealing performance under the high temperature tail gas strikes, improve and use the reliability.

Description

Exhaust manifold sealing structure of medium and heavy diesel engine

Technical Field

The utility model relates to an exhaust manifold, specific well heavy diesel engine exhaust manifold seal structure that says so belongs to well heavy diesel engine exhaust system technical field.

Background

Exhaust manifolds are important components of diesel engines and are typically cast from vermicular or nodular cast iron. Its main function is to guide exhaust from the exhaust duct to the exhaust manifold, contain the exhaust and guide the exhaust to the supercharger. The exhaust manifold also plays a role of fixedly supporting components such as a supercharger, a heat shield plate, and an EGR cooler.

Because the engine waste gas flows through the exhaust manifold, the working temperature difference is extremely large and is-60-750 ℃. The exhaust manifold is prone to low cycle fatigue cracking under alternating cold and hot engine impacts. In the prior art, the common technical scheme for solving the fracture of the exhaust manifold is the exhaust manifold segmentation and shaft retainer ring sealing technology, and the scheme has the defects that the air leakage phenomenon is generated at the initial running stage of an engine and is more serious along with the lengthening of time. Patent document (CN 202732073U) discloses a sealing structure of a split exhaust manifold, in which front and rear exhaust manifold connecting ends are inserted into an intermediate exhaust manifold to connect with the intermediate exhaust manifold; meanwhile, an annular groove is formed in the peripheral surface of the insertion part of the front exhaust manifold, a shaft retainer ring sealing ring is arranged in the annular groove, and an end face sealing ring and an elastic metal wire mesh pad are clamped between the end faces of the front exhaust manifold and the rear exhaust manifold and the step face of the middle section of the exhaust manifold. The defect sealing structure of the scheme mainly uses a retainer ring sealing ring for the shaft, namely, the same strip-shaped metal material is bent into a two-layer annular retainer ring structure which is similar to a key ring structure. The sealing ring has the disadvantage that the transition of the two-layer structure is of a single-layer structure, and the tail gas leaks from the transition. And the sealing ring has high rigidity, poor compensation capability and high process requirement on a matched exhaust manifold, and simultaneously generates abrasion on the joint of the exhaust manifold under the high-frequency vibration of the operation of an engine to cause tail gas leakage. Its first seal structure comprises elastic compensation element and for the shaft retaining ring sealing ring, and the structure is complicated, and elastic compensation element has the damage risk under the direct impact of high temperature tail gas simultaneously, and the piece will get into the booster, damages the blade.

Disclosure of Invention

An object of the utility model is to overcome above-mentioned weak point to a well heavy diesel engine exhaust manifold seal structure is provided, can form more reliable sealing performance under the high temperature tail gas strikes, has improved the use reliability.

According to the technical scheme provided by the utility model, well heavy diesel engine exhaust manifold seal structure includes exhaust manifold anterior segment, exhaust manifold middle section and exhaust manifold back end, exhaust manifold anterior segment and exhaust manifold back end, characterized by are connected respectively at both ends around the exhaust manifold middle section: a front sealing structure is arranged at the joint of the middle section of the exhaust manifold and the front section of the exhaust manifold, and a rear sealing structure is arranged at the joint of the rear section of the exhaust manifold and the front section of the exhaust manifold;

the front sealing structure comprises a first step hole, a second step hole and a third step hole which are arranged on the inner surface of the end part of the middle section of the exhaust manifold, and a first step, a second step and a third step which are arranged on the outer surface of the end part of the front section of the exhaust manifold, wherein the first step hole, the second step hole and the third step hole are respectively in clearance fit connection with the first step, the second step and the third step; a radial sealing ring is arranged between the second step hole and the second step, and an axial sealing ring is arranged between the third step hole and the third step; the rear sealing structure is the same as the front sealing structure.

Furthermore, a positioning spigot which is vertical to the first step is arranged at the front end of the first step on the outer surface of the end part of the front section of the exhaust manifold.

Furthermore, a lifting truncated cone is arranged on one side, close to the second step, of the first step on the outer surface of the end part of the front section of the exhaust manifold.

Furthermore, the radial sealing ring is of a U-shaped structure, the opening end of the radial sealing ring faces the axial end face of the middle section of the exhaust manifold, and the radial sealing ring forms radial elastic sealing between the second step hole and the second step.

Further, the axial sealing ring is of a U-shaped structure, the opening end of the axial sealing ring faces the radial end face of the front section of the exhaust manifold, and the axial sealing ring forms axial elastic sealing between the third step hole and the third step.

Compared with the prior art, the utility model has the advantages that:

the utility model has simple, compact and reasonable structure, can form more reliable sealing performance under the impact of high-temperature tail gas, and improves the use reliability; the lifting conical frustum can further compress the radial size of the radial sealing ring under the pushing of waste gas to form a larger sealing effect; the locating spigot and the first step form a labyrinth seal structure, waste gas can be smoothly guided into the middle section of the exhaust manifold, and the high-temperature waste gas is prevented from directly scouring the axial seal ring and the radial seal ring.

Drawings

Fig. 1 is a front view of the present invention.

FIG. 2 is a front view of a mid-section of an exhaust manifold.

FIG. 3 is a front view of a front section of an exhaust manifold.

Fig. 4 is a front view of the rear section of the exhaust manifold.

FIG. 5 is a front view of a radial seal ring.

FIG. 6 is a front view of the axial seal ring.

Fig. 7 is a half sectional view of the front seal structure.

Description of reference numerals: 1-an exhaust manifold front section, 2-an exhaust manifold middle section, 3-an exhaust manifold rear section, 4-a first step hole, 5-a second step hole, 6-a third step hole, 7-a first step, 8-a second step, 9-a third step, 10-a radial sealing ring, 11-an axial sealing ring, 12-a lifting cone frustum and 13-a positioning spigot.

Detailed Description

The invention will be further described with reference to the embodiments shown in the drawings to which:

as shown in FIGS. 1 to 7, the present invention mainly comprises an exhaust manifold front section 1, an exhaust manifold middle section 2 and an exhaust manifold rear section 3,

exhaust manifold anterior segment 1 and exhaust manifold back end 3 are connected respectively to exhaust manifold middle section 2 front and back both ends, and exhaust manifold middle section 2 and the 1 junction of exhaust manifold anterior segment are equipped with preceding seal structure, and exhaust manifold back end 3 and the 1 junction of exhaust manifold anterior segment are equipped with back seal structure.

The front sealing structure comprises a first step hole 4, a second step hole 5 and a third step hole 6 which are arranged on the inner surface of the end part of the middle section 2 of the exhaust manifold, and a first step 7, a second step 8 and a third step 9 which are arranged on the outer surface of the end part of the front section 1 of the exhaust manifold, wherein the first step hole 4, the second step hole 5 and the third step hole 6 are respectively in clearance fit connection with the first step 7, the second step 8 and the third step 9.

And a radial sealing ring 10 of a U-shaped structure is arranged between the second step hole 5 and the second step 8, the opening end of the radial sealing ring 10 faces the axial end face of the middle section 2 of the exhaust manifold, and the radial sealing ring 10 forms radial elastic sealing between the second step hole 5 and the second step 8. When the exhaust manifold is expanded by heat, the radial dimension of the radial sealing ring 10 is further compressed, and a greater sealing effect is formed.

An axial sealing ring 11 of a U-shaped structure is arranged between the third step hole 6 and the third step 9, the opening end of the axial sealing ring 11 faces the radial end face of the exhaust manifold front section 1, and the axial sealing ring 11 forms axial elastic sealing between the third step hole 6 and the third step 9. When the exhaust manifold is heated and expanded, the axial size of the axial sealing ring 11 is further compressed, and a larger sealing effect is formed.

The front end of the first step 7 on the outer surface of the end part of the front section 1 of the exhaust manifold is provided with a positioning spigot 13 vertical to the first step 7, the positioning spigot 13 and the first step 7 form a labyrinth seal structure, waste gas can be smoothly guided into the middle section of the exhaust manifold, and high-temperature waste gas is prevented from directly scouring the axial seal ring and the radial seal ring.

A lifting conical frustum 12 is arranged on one side, close to a second step 8, of a first step 7 on the outer surface of the end portion of the front section 1 of the exhaust manifold, when waste gas enters a first sealing position through a seam allowance in a small amount, pressure is generated to push a U-shaped radial sealing ring to move towards the front section and the rear section of the exhaust manifold respectively, the U-shaped radial sealing ring is further compressed under the lifting action of a conical surface, and a larger sealing effect is formed.

The rear sealing structure is the same as the front sealing structure.

The stepped sealing structures of the front sealing structure and the rear sealing structure strengthen the sealing capability of the sealing structures through the mutual movement of the tail gas pressure and the thermal expansion of the exhaust manifold. The used axial sealing ring and the radial sealing ring have the functions of elastic compensation and sealing at the same time, and have reliable and efficient sealing capability under the condition of high vibration in the operation of the engine. The utility model provides an exhaust manifold segmentation and this difficult problem of sealing, compare in the scheme of the same kind, the utility model has the advantages of high reliability and simple structure.

The utility model discloses simple structure, compactness, reasonable can form more reliable sealing performance under high temperature tail gas strikes, has improved the use reliability.

Claims

1. The utility model provides a well heavy diesel engine exhaust manifold seal structure, includes exhaust manifold anterior segment (1), exhaust manifold middle section (2) and exhaust manifold back end (3), exhaust manifold anterior segment (1) and exhaust manifold back end (3), characterized by are connected respectively at both ends around exhaust manifold middle section (2): a front sealing structure is arranged at the joint of the middle section (2) of the exhaust manifold and the front section (1) of the exhaust manifold, and a rear sealing structure is arranged at the joint of the rear section (3) of the exhaust manifold and the front section (1) of the exhaust manifold;

the front sealing structure comprises a first step hole (4), a second step hole (5) and a third step hole (6) which are arranged on the inner surface of the end part of the middle section (2) of the exhaust manifold, and a first step (7), a second step (8) and a third step (9) which are arranged on the outer surface of the end part of the front section (1) of the exhaust manifold, wherein the first step hole (4), the second step hole (5) and the third step hole (6) are respectively in clearance fit connection with the first step (7), the second step (8) and the third step (9); a radial sealing ring (10) is arranged between the second step hole (5) and the second step (8), and an axial sealing ring (11) is arranged between the third step hole (6) and the third step (9); the rear sealing structure is the same as the front sealing structure.

2. The sealing structure of exhaust manifold of medium and heavy diesel engine as claimed in claim 1, wherein: and a positioning spigot (13) vertical to the first step (7) is arranged at the front end of the first step (7) on the outer surface of the end part of the front section (1) of the exhaust manifold.

3. The sealing structure of exhaust manifold of medium and heavy diesel engine as claimed in claim 1, wherein: and a lifting truncated cone (12) is arranged on one side, close to the second step (8), of the first step (7) on the outer surface of the end part of the front section (1) of the exhaust manifold.

4. The sealing structure of exhaust manifold of medium and heavy diesel engine as claimed in claim 1, wherein: the radial sealing ring (10) is of a U-shaped structure, the opening end of the radial sealing ring (10) faces the axial end face of the middle section (2) of the exhaust manifold, and the radial sealing ring (10) forms radial elastic sealing between the second step hole (5) and the second step (8).

5. The sealing structure of exhaust manifold of medium and heavy diesel engine as claimed in claim 1, wherein: the axial sealing ring (11) is of a U-shaped structure, the opening end of the axial sealing ring (11) faces the radial end face of the front section (1) of the exhaust manifold, and the axial sealing ring (11) forms axial elastic sealing between the third step hole (6) and the third step (9).