CN112682209A

CN112682209A - Cylinder head and engine

Info

Publication number: CN112682209A
Application number: CN202011575716.6A
Authority: CN
Inventors: 王有治; 霍翠英; 吕祥; 李连升; 崔凯
Original assignee: Weichai Power Co Ltd
Current assignee: Weichai Power Co Ltd
Priority date: 2020-12-28
Filing date: 2020-12-28
Publication date: 2021-04-20

Abstract

The application relates to the technical field of engines and discloses a cylinder cover and an engine, wherein the cylinder cover comprises a cylinder cover main body, an exhaust valve penetrating through the cylinder cover main body, an exhaust passage communicated with the exhaust valve and an edge, wherein the circumferential sleeve of the exhaust valve is arranged on a valve guide pipe of the exhaust valve, and the cylinder cover further comprises a heat insulation component arranged at the bottom of the valve guide pipe and fixedly connected with the valve guide pipe. The application discloses cylinder head can effectively avoid exhausting and directly assaults the valve guide and lead to its high temperature to avoid the lubricating oil of valve guide hole to lose efficacy and produce the trouble of valve wearing and tearing guide under high temperature.

Description

Cylinder head and engine

Technical Field

The application relates to the technical field of engines, in particular to a cylinder cover and an engine.

Background

Along with the continuous improvement of the power per liter of the engine, the heat load of the engine is continuously improved, the exhaust temperature is correspondingly continuously improved, particularly the exhaust temperature of a gas engine can reach more than 800 ℃, and the risk of abrasion of a cylinder cover exhaust valve guide pipe caused by high-temperature gas due to overhigh temperature exists.

Generally speaking, an exhaust passage and a valve guide pipe of a cylinder cover are influenced by the temperature of exhaust passage fuel gas, particularly the bottom of the valve guide pipe is directly impacted by the fuel gas, the temperature is high, so that a lubricant in an inner hole of the valve guide pipe disappears under the action of long-time high temperature, the abrasion between the valve guide pipe and a valve is aggravated, and finally the eccentric wear of the valve guide pipe and the breakage fault of the valve occur.

Disclosure of Invention

The embodiment of the invention provides a cylinder cover, which can effectively avoid overhigh temperature caused by direct impact of exhaust on a valve guide pipe, thereby avoiding the failure of the valve guide pipe due to the failure of lubricating oil in an inner hole of the valve guide pipe at high temperature.

In order to achieve the above object, an embodiment of the present invention provides a cylinder head, which includes a cylinder head main body, an exhaust valve penetrating through the cylinder head main body, an exhaust passage communicating with the exhaust valve, and a valve guide pipe sleeved on the exhaust valve along a circumferential direction of the exhaust valve, and further includes a heat insulating member disposed at a bottom of the valve guide pipe and fixedly connected to the valve guide pipe.

Above-mentioned cylinder head sets up thermal-insulated part through the bottom at the valve guide, and when engine heat load when constantly improving, the gas temperature that comes from the exhaust passage acted on thermal-insulated part, and thermal-insulated part can separate between gas temperature and the valve guide to guarantee that the lubricating oil of valve guide hole can not become invalid under the effect of long-time high temperature, thereby avoided the wearing and tearing between valve guide and the valve, reduced the production of valve broken end trouble.

Therefore, according to the cylinder cover provided by the embodiment of the invention, the heat insulation part is arranged at the bottom of the valve guide pipe, so that the problem that the temperature of the valve guide pipe is too high due to direct impact of exhaust on the valve guide pipe can be effectively avoided, and the problem that the valve abrasion guide pipe is generated due to failure of lubricating oil in an inner hole of the valve guide pipe at high temperature is avoided.

Preferably, the heat insulation component is an annular structure sleeved on the exhaust valve along the circumferential direction of the exhaust valve.

Preferably, one side of the heat insulation member facing the valve guide is provided with a plurality of mounting grooves for fixedly connecting the valve guide.

Preferably, the heat insulating member and the valve guide are fixed by a bolt.

Preferably, the heat insulation component and the valve guide pipe are in interference fit.

Preferably, a clearance is provided between the valve guide and the heat conductive member in an extending direction of the exhaust valve.

Preferably, the gap is greater than 1 mm.

Preferably, the heat insulating member has a distance from the exhaust valve in a radial direction of the exhaust valve.

Preferably, the distance is greater than 0.5 mm.

Preferably, the embodiment of the invention further provides an engine, which comprises the cylinder cover as described in any one of the above.

Drawings

FIG. 1 is a schematic cross-sectional view of a prior art cylinder head;

FIG. 2 is a schematic cross-sectional view of a cylinder head according to an embodiment of the present disclosure;

FIG. 3 is an enlarged schematic view of a cross-sectional structure of a heat insulating member according to an embodiment of the present application;

fig. 4 is a schematic structural view of a heat insulating member in an embodiment of the present application.

In the figure:

01-an exhaust valve; 02-exhaust passage; 03-valve guide; 1-a cylinder cover main body; 2-an exhaust valve; 3-a valve guide; 4-an exhaust passage; 5-a heat insulating member; 51-mounting groove.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

As shown in fig. 1, fig. 1 is a schematic cross-sectional structure diagram of a cylinder head in the prior art, wherein an exhaust passage 02 and a valve guide 03 are affected by the temperature of the exhaust passage 02 gas, especially the bottom of the valve guide 03 is directly impacted by the gas, the temperature is high, so that lubricant in an inner hole of the valve guide 03 disappears under the action of long-time high temperature, further the abrasion between the valve guide and an exhaust valve 01 is aggravated, and finally the valve guide 03 is worn eccentrically and the valve is broken.

In view of this, referring to fig. 2-3, the present invention provides a cylinder head, which includes a cylinder head main body 1, an exhaust valve 2 penetrating through the cylinder head main body 1, an exhaust passage 4 communicating with the exhaust valve 2, a valve guide 3 sleeved on the exhaust valve 2 along a circumferential direction of the exhaust valve 2, and a heat insulating member 5 disposed at a bottom of the valve guide 3 and fixedly connected to the valve guide 3.

Above-mentioned cylinder head, through setting up heat insulating part 5 in the bottom of valve guide 3, when engine heat load when constantly improving, the gas temperature that comes from exhaust passage 4 acts on heat insulating part 5, and heat insulating part 5 can separate between gas temperature and the valve guide 3 to guarantee that the lubricating oil of valve guide 3 hole can not become invalid under the effect of long-time high temperature, thereby avoided wearing and tearing between valve guide 3 and the valve, reduced the production of valve broken end trouble.

Therefore, according to the cylinder head provided by the embodiment of the invention, the heat insulation part 5 is arranged at the bottom of the valve guide 3, so that the problem that the temperature of the valve guide 3 is too high due to direct impact of exhaust on the valve guide 3 can be effectively avoided, and the problem that the valve abrasion guide fails due to the failure of lubricating oil in the inner hole of the valve guide 3 at high temperature is avoided.

It should be noted that the material of the heat insulation component 5 is a non-metal material, and the specific material thereof can be changed according to different production requirements.

In some embodiments, the heat insulation component 5 may be an annular structure that is sleeved on the exhaust valve 2 along the circumferential direction of the exhaust valve 2, and the annular structure can completely separate the bottom of the valve guide 3 from the temperature of the gas from the exhaust passage 4, so as to better avoid the lubricating oil in the inner hole of the valve guide 3 from being out of order.

On the basis, as shown in fig. 4, the side of the heat insulating member 5 with the annular structure facing the valve guide 3 is provided with a plurality of mounting grooves 51 for fixedly connecting the valve guide 3, and when the heat insulating member 5 is mounted at the bottom of the valve guide 3, the bottom of the valve guide 3 is clamped with the mounting grooves 51, so that the valve guide 3 and the heat insulating member 5 are kept fixed, and the heat insulating effect of the heat insulating member 5 on the valve guide 3 when the cylinder head is in use is further improved.

In one embodiment, the heat insulating member 5 and the valve guide 3 may be fixed by bolts, and the valve guide 3 and the heat insulating member 5 may be connected by bolts, thereby ensuring stable connection between the valve guide 3 and the heat insulating member 5.

Also, as another implementation manner, the heat insulation member 5 and the valve guide 3 may be in an interference fit to ensure a stable connection between the valve guide 3 and the heat insulation member 5.

In some embodiments, as shown in fig. 3, when the heat insulating member 5 is installed at the bottom of the valve guide 3, a certain gap a may be left between the heat insulating member 5 and the bottom of the valve guide 3, and this gap a may be used for further heat insulation, and when the temperature of the gas from the exhaust passage 4 acts on the heat insulating member 5, the temperature of the gas is transmitted to the valve guide 3 through the gap a via the heat insulating member 5, so that the impact of the temperature of the gas on the valve guide 3 can be further reduced.

It should be noted that the gap a should be larger than 1 mm.

In some embodiments, when the heat insulating member 5 is installed at the bottom of the valve guide 3, a certain distance b may be provided between the heat insulating member 5 and the exhaust valve 2, and the distance may be used to avoid collision between the heat insulating member 5 and the valve, so as to reduce impact of the heat insulating member 5 on the valve during operation.

Wherein, it should be noted that the distance b should be larger than 0.5 mm.

Based on the same invention idea, an embodiment of the invention may further provide an engine, where the engine includes the cylinder head in any embodiment of the application, and the cylinder head is provided with the heat insulation component 5 at the bottom of the valve guide 3, so as to effectively avoid the problem that the temperature of the valve guide 3 is too high due to direct restart of exhaust, and further avoid the failure of the valve guide due to failure of lubricating oil in the inner bore of the valve guide 3 at high temperature, and therefore, the engine in the embodiment of the invention can ensure stable matching between components in the operation process, and thus improve the stability of the engine operation.

It will be apparent to those skilled in the art that various changes and modifications may be made in the embodiments of the present invention without departing from the spirit and scope of the invention. Thus, if such modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include such modifications and variations.

Claims

1. The cylinder cover comprises a cylinder cover main body, an exhaust valve penetrating through the cylinder cover main body, an exhaust passage communicated with the exhaust valve, and a valve guide pipe sleeved on the exhaust valve along the circumferential direction of the exhaust valve, and is characterized by further comprising a heat insulation component arranged at the bottom of the valve guide pipe and fixedly connected with the valve guide pipe.

2. The cylinder head of claim 1, wherein the heat insulating member is an annular structure that is fitted over the exhaust valve in a circumferential direction of the exhaust valve.

3. The cylinder head according to claim 2, wherein a side of the heat insulating member facing the valve guide is provided with a plurality of mounting grooves for fixedly coupling the valve guide.

4. The cylinder head according to claim 3, wherein the heat insulating member is fixed to the valve guide by a bolt.

5. The cylinder head of claim 3, wherein said thermal insulation member is an interference fit with said valve guide.

6. The cylinder head according to claim 1, wherein a clearance is provided between the valve guide and the heat conductive member in an extending direction of the exhaust valve.

7. The cylinder head of claim 6, wherein said gap is greater than 1 mm.

8. The cylinder head of claim 1, wherein said thermal insulating member is spaced from said exhaust valve in a radial direction of said exhaust valve.

9. The cylinder head of claim 8, wherein said distance is greater than 0.5 mm.

10. An engine, characterized by comprising a cylinder head according to any one of claims 1 to 9.