CN201546800U - Combustion chambers of small displacement engines - Google Patents

Abstract

The utility model relates to the field of engine combustion chambers, which discloses a combustion chamber of a small-displacement engine, comprising a cylinder body, an intake valve, an exhaust valve, a cylinder head, a spark plug and a piston; the cylinder head is provided with different slopes The slope and the arc surface form a roof shape; the head of the piston is bowl-shaped; the intake valve and the exhaust valve are respectively located on the slope of the cylinder head; the A spark plug is located between the exhaust valve and the intake valve on one side of the exhaust valve. The beneficial effects of the utility model are: the utility model makes the structure of the combustion chamber of the engine more compact, can increase the compression ratio, the face-to-volume ratio is smaller, and reduces the heat loss; the valve arrangement method of two inlets and two rows is adopted, and the valves are arranged reasonably The head improves the intake and exhaust effects of the engine, thereby improving performance indicators such as engine power.

Description

Combustion chambers of small displacement engines

technical field

The utility model relates to the field of engine combustion chambers, in particular to a combustion chamber of a small-displacement engine.

Background technique

Usually, when the piston runs to the compression top dead center, the space formed above the top surface of the piston and below the bottom surface of the cylinder head is called the combustion chamber of the engine. The structure of the combustion chamber of the engine is directly related to the mixing and combustion of the combustible mixture in the engine cylinder. The process, therefore, has a significant impact on the engine's dynamic performance, economic performance and emission levels. At present, the common shapes of the combustion chambers of traditional engines mainly include hemispherical combustion chambers, bathtub-shaped combustion chambers, wedge-shaped combustion chambers, etc., all of which have certain problems such as insufficient compact structure, small compression ratio, and large surface-to-volume ratio of the combustion chamber to varying degrees. , Flame propagation distance is long, and the airflow movement in the cylinder is not strong enough, etc., especially in small displacement engines. As a result, the combustion characteristics of the engine are often not ideal enough to meet the current requirements for power performance, economic performance and emission levels of small-displacement engines. Due to the irregularity of the combustion chamber, the measurement method of the volume of the combustion chamber of the cylinder head mainly adopts the titration method at present. The titration method is to drop kerosene into the combustion chamber through the burette after the cylinder head assembly with the intake and exhaust valves and spark plugs assembled, and then Measure the volume of kerosene titrated by the burette to obtain the volume of the combustion chamber. The disadvantage of the titration method is that there are many procedures, it takes a long time, it is not suitable for large-scale production, and the production efficiency is reduced.

Contents of the invention

In order to solve the problems in the prior art, the utility model proposes a high compression ratio engine combustion chamber with a combustion chamber volume detection function, which solves the problem of poor combustion effect and combustion Room volume measurement is too complex and other issues.

The technical solution adopted by the utility model to solve the problems of the prior art is: design and manufacture a combustion chamber of a small-displacement engine, including a cylinder block, an intake valve, an exhaust valve, a cylinder head, a spark plug and a piston; The cover is provided with slopes and arc surfaces with different slopes, and the slopes and arc surfaces form a roof shape; the head of the piston is bowl-shaped; the intake valve and exhaust valve are respectively located on the cylinder head on the slope; the spark plug is located between the exhaust valve and the intake valve and on one side of the exhaust valve.

The further improvement of the utility model is that: the exhaust valve and the intake valve are symmetrical structures respectively.

The further improvement of the utility model is that: the intake valve is located on a slope with a relatively small slope on the cylinder head; the exhaust valve is located on a slope with a relatively large slope on the cylinder head; The diameter of the valve is larger than the diameter of the exhaust valve.

The further improvement of the utility model is: the top surface of the piston is higher than the upper plane of the cylinder body; the top surface of the piston is provided with an escape pit.

The further improvement of the utility model is that: the lower bottom surface of the cylinder head, the slope corresponding to the intake valve, the slope corresponding to the exhaust valve and the corresponding slope on the piston form a squeeze area to form a squeeze flow.

The further improvement of the utility model is: the two sides of the spark plug hole are respectively cast with measuring planes along the back direction; the measuring planes are parallel to the bottom plane of the cylinder head.

The further improvement of the utility model is that: the measuring plane includes a large circular surface and two small circular surfaces connected; the large circular surface corresponds to the position of the spark plug hole; the two small circular surfaces are symmetrically distributed on the Both sides of the spark plug hole.

The further improvement of the utility model is: the outer periphery of the combustion chamber of the small displacement engine is circular.

The further improvement of the utility model is: the intake valve and the exhaust valve are respectively two intake valves and two exhaust valves.

The beneficial effects of the utility model are: the utility model makes the structure of the combustion chamber of the engine more compact, can increase the compression ratio, the surface-to-volume ratio is smaller, and reduces heat loss; the combustion chamber is designed with a squish area, which can further improve the combustible mixing The combustion speed of gas combustion ensures that the combustible mixture is fully combusted, while enhancing the power and improving the economy, it reduces the content of HC, CO and NO _X in the exhaust emission of the vehicle; the valve arrangement of two inlets and two rows is adopted, Reasonable arrangement of the valve head improves the intake and exhaust effects of the engine, thereby improving performance indicators such as engine power; the measurement method of the combustion chamber is simple and easy, which greatly improves the quality inspection speed in the mass production process of the cylinder head.

Description of drawings

Fig. 1 is the schematic diagram of the combustion chamber of the utility model small-displacement engine.

Fig. 2 is a top view of a combustion chamber of a small-displacement engine of the present invention.

Detailed ways

Below in conjunction with accompanying drawing, the utility model is further described.

A combustion chamber of a small-displacement engine includes a cylinder block, an intake valve, an exhaust valve, a cylinder head, a spark plug and a piston; The arc surface forms a ridge shape; the head of the piston is bowl-shaped; the intake valve and the exhaust valve are respectively located on the slope on the cylinder head; the spark plug is located between the exhaust valve and the intake valve between and on one side of the exhaust valve.

The exhaust valve and the intake valve are symmetrical structures respectively.

The intake valve is located on a slope with a relatively small slope on the cylinder head; the exhaust valve is located on a slope with a relatively large slope on the cylinder head; the diameter of the intake valve is larger than that of the exhaust The diameter of the door.

The top surface of the piston is higher than the upper plane of the cylinder body; the top surface of the piston is provided with an escape pit.

The lower bottom surface of the cylinder head, the slope corresponding to the intake valve, the slope corresponding to the exhaust valve and the slope corresponding thereto on the piston form a squeeze area to form a squeeze flow.

The two sides of the spark plug hole are respectively cast with measuring planes along the back direction; the measuring planes are parallel to the bottom plane of the cylinder head.

The measurement plane includes a large circular surface connected to two small circular surfaces; the large circular surface corresponds to the position of the spark plug hole; and the two small circular surfaces are symmetrically distributed on both sides of the spark plug hole.

The outer periphery of the combustion chamber of the small displacement engine is circular.

The intake valve and the exhaust valve are respectively two intake valves and two exhaust valves.

In an example, as shown in FIG. 1 , a combustion chamber of a small-displacement engine is composed of intake valve 3 , exhaust valve 6 , cylinder head 5 , spark plug 4 and piston 1 . The outer periphery of the combustion chamber is circular; the upper cavity of the combustion chamber is ridge-shaped, which is composed of two slopes with different slopes on the cylinder head 5 and the arc surfaces on both sides; the lower cavity of the combustion chamber is bowl-shaped, with the top of the bowl The head of the piston constitutes. There are two intake valves 3, which are symmetrical structures, and two exhaust valves, which are also symmetrical structures, are respectively located on the two slopes of the upper cavity. The spark plug 4 is located between the exhaust valve 6 and the intake valve 3, near the exhaust valve 6 side.

The combustion chamber adopts a two-inlet and two-row valve setting method, which maximizes the intake and exhaust area and improves the intake and exhaust effect. Considering the importance of the intake system, the intake valve is slightly larger than the exhaust valve. The slope slope on the exhaust side is greater than the slope slope on the intake side, so that the valves can be arranged reasonably so that the diameter of the intake valve is larger than the diameter of the exhaust valve, which increases the intake air volume and thus improves the engine power.

In order to improve the compression ratio of the engine and reduce the surface volume ratio, the top surface of the piston 1 is designed to be higher than the upper plane of the cylinder block. At the same time, in order to prevent the valve from colliding with the top surface of the piston 1, corresponding avoidance pits are processed on the top surface of the piston 1.

The design of the intake port is optimized, and a strong tumble flow field can be formed in the cylinder during intake; when compressed, the slope surface on the intake and exhaust sides of the lower bottom surface of the cylinder head 5 and the corresponding slope surface on the piston form a squeeze flow In zone 2, a strong squishing effect can be formed when the piston moves upward, which improves the combustion speed of the combustible mixture, ensures the full combustion of the combustible mixture, and improves the thermal efficiency. Furthermore, the power performance of the engine is improved, the economy is improved, and the content of HC, CO and NOX in the automobile exhaust emission is reduced.

Two measuring planes are respectively cast on the two sides of the spark plug hole 4 on the top of the combustion chamber along the direction of the spine. The measuring planes are parallel to the bottom plane of the cylinder head and are respectively formed by connecting a large circular surface 8 and two small circular surfaces 7. The large circular surface 8 Corresponding to the position of the spark plug hole, two small circular surfaces 7 are symmetrically distributed on both sides of the spark plug hole.

The measurement plane of the combustion chamber is cast, parallel to the bottom plane of the cylinder head, and about 0.8mm to 1.2mm higher than the bottom surface of the combustion chamber; the large circular surface 8 corresponds to the position of the spark plug hole, and most of them are removed when drilling the spark plug hole; and the two small planes 7 is mainly used to measure the combustion chamber volume of the cylinder head blank and the finished cylinder head. By measuring the actual distance between the plane and the bottom plane of the cylinder head, and comparing it with the design value, it can be inferred whether the volume of the combustion chamber of the cylinder head meets the requirements, and then judge whether the product is qualified. The measurement method of the combustion chamber is simple and easy, and special equipment can be designed for measurement, which is suitable for mass production.

In the specific implementation process, as shown in Fig. 1, a combustion chamber for a small-displacement engine is composed of intake valve 3, exhaust valve 6, cylinder head 5, spark plug 4, piston 1 and other parts. Adopt the design scheme that the intake valve is slightly larger than the exhaust valve, such as the slope slope of the exhaust side is 16.5°, which is greater than the slope slope (15°) of the intake side, so that the valves can be arranged reasonably so that the diameter of the intake valve is larger than that of the exhaust valve The diameter increases the intake air volume, which in turn increases the engine power. At the same time, there is a squeeze surface in the combustion chamber, and at the end of the compression stroke, a strong airflow movement will be formed in the cylinder to accelerate the combustion process. Increase the height of the top surface of the piston so that the compression ratio of the engine is greater than 9. As shown in Figure 2, two measurement planes are respectively cast along the back direction of the spark plug hole on the top of the combustion chamber. The measurement planes are parallel to the bottom plane of the cylinder head and are formed by connecting a large circular surface 8 and two small circular surfaces 7 respectively. , the large circular surface corresponds to the position of the spark plug hole, and the two small circular surfaces are symmetrically distributed on both sides of the spark plug hole.

The above content is a further detailed description of the utility model in combination with specific preferred embodiments, and it cannot be assumed that the specific implementation of the utility model is only limited to these descriptions. For a person of ordinary skill in the technical field to which the utility model belongs, without departing from the concept of the utility model, some simple deduction or substitutions can also be made, which should be regarded as belonging to the protection scope of the utility model.

Claims (9)

1. a combustion chamber of a small-displacement engine, comprising a cylinder block, is characterized in that: it also includes an intake valve, an exhaust valve, a cylinder head, a spark plug and a piston; The arc surface, the slope and the arc surface form a roof shape; the head of the piston is bowl-shaped; the intake valve and exhaust valve are respectively located on the slope of the cylinder head; the spark plug is located on the between the exhaust valve and the intake valve and on one side of the exhaust valve. 2. The combustion chamber of the small-displacement engine according to claim 1, wherein the exhaust valve and the intake valve are symmetrical structures. 3. The combustion chamber of the small-displacement engine according to claim 1, wherein the intake valve is located on a slope with a relatively small slope on the cylinder head; the exhaust valve is located on the cylinder head On a slope with a relatively large slope; the diameter of the intake valve is larger than the diameter of the exhaust valve. 4. The combustion chamber of the small-displacement engine according to claim 1, characterized in that: the top surface of the piston is higher than the upper plane of the cylinder block; the top surface of the piston is provided with an escape pit. 5. The combustion chamber of the small-displacement engine according to claim 1, characterized in that: the bottom surface of the cylinder head, the slope corresponding to the intake valve, the slope corresponding to the exhaust valve, and the corresponding slope on the piston The inclined plane forms a squash area to form a squish flow. 6. The combustion chamber of the small-displacement engine according to claim 1, characterized in that: the two sides of the spark plug hole are respectively cast with measuring planes along the back direction; the measuring planes are parallel to the bottom plane of the cylinder head. 7. according to the combustion chamber of the described small-displacement engine of claim 6, it is characterized in that: described measuring plane comprises a large circular surface and two small circular surfaces are connected to form; Described large circular surface corresponds to the position of described spark plug hole; The two small circular planes are symmetrically distributed on both sides of the spark plug hole. 8. The combustion chamber of the small-displacement engine according to claim 1, wherein the outer periphery of the combustion chamber of the small-displacement engine is circular. 9. The combustion chamber of the small-displacement engine according to claim 1, wherein the intake valve and the exhaust valve are respectively two intake valves and two exhaust valves.

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