1. The cylinder cover comprises an air inlet throat and an exhaust throat and is characterized in that an air inlet chamfer is arranged at a bottom hole of the air inlet throat and comprises an arc rotary chamfer, the rotary central line of the arc rotary chamfer is obliquely arranged relative to the axis of the air inlet throat, and the lower end opening of the air inlet chamfer faces the lower part of the exhaust throat.

2. The cylinder head of claim 1, wherein a longitudinal section of the intake chamfer is a straight line or a curved line.

3. The cylinder head according to claim 1, wherein a longitudinal section of the intake chamfer is a curve convex toward an inside of the cylinder.

4. The cylinder head according to claim 1, wherein a gyration centerline of the circular-arc gyration chamfer part is inclined at an angle θ of 0 ° < θ ≦ 30 ° with respect to an axis of the intake throat.

5. The cylinder head of claim 1, wherein the intake chamfer further comprises a guide chamfer portion connected to a side of the radiused chamfered portion adjacent to the exhaust throat, the guide chamfer portion projecting toward the exhaust throat relative to the radiused chamfered portion.

6. The cylinder head of claim 5, wherein an intersection of the guide chamfer and the cylinder head bottom surface is a guide chamfer contour line, the guide chamfer contour line including a broken line and/or a rounded curve.

7. The cylinder head according to claim 5, wherein the rounded return chamfer and the guide chamfer are connected by a rounded transition chamfer having a center of curvature located outside the intake chamfer between both ends in the circumferential direction of the intake chamfer.

8. The cylinder cover according to claim 7, characterized in that the intersection line of the circular arc rotary chamfer part and the bottom surface of the cylinder cover is a circular arc rotary chamfer contour line, the intersection line of the guide chamfer part and the bottom surface of the cylinder cover is a guide chamfer contour line, the intersection line of the circular arc transition chamfer surface and the bottom surface of the cylinder cover is a circular arc transition chamfer contour line, the intersection point of the rotary center line of the circular arc rotary chamfer part and the bottom surface of the cylinder cover is a reference point, the diameter of the circular arc rotary chamfer contour line is 1.28-1.47 times of the inner diameter of the intake valve seat ring, the distance between two ends of the guide chamfer contour line is 0.5-0.6 times of the inner diameter of the intake valve seat ring, the farthest distance between the guide chamfer contour line and the reference point is 0.55-0.65 times of the inner diameter of the intake valve seat ring, and the radius of the circular arc transition chamfer contour line is 2-8 mm.

9. The cylinder cover according to any one of claims 1 to 8, wherein the cylinder cover is provided with a plurality of intake throats, each intake throat is connected with an intake passage, and each intake passage is arranged separately or connected into a whole at one end far away from the intake throats.

10. The cylinder head according to any one of claims 1 to 8, wherein the cylinder head is provided with a plurality of the intake throats, and the intake chamfers of at least two of the intake throats are different.

11. The cylinder head according to any one of claims 1 to 8, comprising a head inlet port arranged at a side face or a top face or a bottom face of the cylinder head.

12. A gas engine, characterized by comprising a cylinder head according to any one of claims 1-11.

Background

With the development of gas engine technology, more and more gas engines are transformed on the basis of diesel engines at present. In the case of a diesel engine, the combustion mode is diffusion combustion, and a certain degree of swirl helps the oil bundles to mix with air, thereby improving the combustion process, so that an air inlet passage in a cylinder head of the gas engine is required to organize the air flow to generate a sufficient swirl ratio during the air intake process. Wherein, the vortex refers to the gas rotational flow movement organized around the cylinder axial direction.

However, the combustion mode of the gas engine is premixed combustion, the requirement on the strength of vortex is not high, and small-scale turbulent motion is needed to form a flame wrinkle surface, so that the flame propagation speed is increased, and the heat efficiency is improved, wherein the turbulent motion refers to small rotational flow which is generated in a flow field when the air flow speed is high and has unfixed directions, and is different from laminar motion. For a gas engine, the strength of the vortex does not need to be increased, and the increase of the tumble strength in the cylinder can be beneficial to forming turbulence at the end of compression and generating enough turbulent kinetic energy when the piston moves up to the top dead center, so that the aim of optimizing combustion is fulfilled. Wherein, the tumble refers to the gas rotational flow motion of which the rotation central axis is vertical to the axial direction of the cylinder sleeve.

Therefore, for the existing gas engine cylinder cover which is designed by integrally modifying the diesel engine cylinder cover, tumble flow required by the gas engine is difficult to generate in the cylinder.

Therefore, how to improve the tumble strength in the cylinder of the gas engine is a technical problem that needs to be solved by those skilled in the art.

Disclosure of Invention

In view of the above, a first object of the present invention is to provide a cylinder head to generate the tumble motion required by a gas engine by the gas entering the cylinder, so as to improve the thermal efficiency of the gas engine. Another object of the present invention is to provide a gas engine comprising the above cylinder head.

In order to achieve the purpose, the invention provides the following technical scheme:

a cylinder cover comprises an air inlet throat and an exhaust throat, wherein an air inlet chamfer is arranged at a bottom hole of the air inlet throat and comprises an arc rotary chamfer part, the rotary central line of the arc rotary chamfer part is obliquely arranged relative to the axis of the air inlet throat, and the lower end opening of the air inlet chamfer part faces the exhaust throat.

Preferably, the longitudinal section of the air inlet chamfer is a straight line or a curve.

Preferably, the longitudinal section of the air inlet chamfer is a curve protruding towards the inner direction of the air cylinder.

Preferably, the inclination angle theta of the gyration central line of the circular arc gyration chamfer part relative to the axis of the air inlet throat opening satisfies 0 degrees < theta < 30 degrees.

Preferably, the air inlet chamfer further comprises a guide chamfer part, the guide chamfer part is connected to one side, close to the exhaust throat, of the circular arc rotary chamfer part, and the guide chamfer part protrudes towards the exhaust throat relative to the circular arc rotary chamfer part.

Preferably, the intersection line of the guide chamfer part and the bottom surface of the cylinder cover is a guide chamfer contour line, and the guide chamfer contour line comprises a broken line and/or a smooth curve.

Preferably, the circular arc gyration chamfer and the guide chamfer are connected through a circular arc transition chamfer surface between two ends along the circumferential direction of the air inlet chamfer, and the curvature center of the circular arc transition chamfer is positioned at the outer side of the air inlet chamfer.

Preferably, the intersection line of the circular arc rotary chamfer part and the bottom surface of the cylinder cover is a circular arc rotary chamfer contour line, the intersection line of the guide chamfer part and the bottom surface of the cylinder cover is a guide chamfer contour line, the intersection line of the circular arc transition chamfer surface and the bottom surface of the cylinder cover is a circular arc transition chamfer contour line, the intersection point of the rotary center line of the circular arc rotary chamfer part and the bottom surface of the cylinder cover is a reference point, the diameter of the circular arc rotary chamfer contour line is 1.28-1.47 times of the inner diameter of the intake valve seat ring, the distance between two ends of the guide chamfer contour line is 0.5-0.6 times of the inner diameter of the intake valve seat ring, the distance between the guide chamfer contour line and the reference point is 0.55-0.65 times of the inner diameter of the intake valve seat ring, and the radius of the circular arc transition chamfer contour line is 2-8 mm.

Preferably, the cylinder head is provided with a plurality of air inlet throats, and each air inlet throat is connected with the intake duct respectively, and each the intake duct is separated to be arranged or each the intake duct is keeping away from the one end of air inlet throat connects as an organic whole.

Preferably, the cylinder head is provided with a plurality of the intake throats, and the intake chamfers of at least two of the intake throats are different.

Preferably, the cylinder further comprises a head inlet port disposed at a side or top or bottom surface of the cylinder head.

In order to achieve the above object, the present invention provides a cylinder head including an intake throat and an exhaust throat, wherein a bottom hole of the intake throat is provided with an intake chamfer, the intake chamfer includes a circular arc-shaped turned chamfer portion, a turning center line of the circular arc-shaped turned chamfer portion is arranged obliquely with respect to an axis of the intake throat and a lower end opening of the intake chamfer portion is arranged toward the exhaust throat.

The working principle of the invention is as follows:

when the gas engine cylinder inhales, the intake valve is opened, the inlet air current flows through the air inlet channel in proper order, the intake valve seat ring and the inlet chamfer and then enters the cylinder, because the gyration central line of the circular arc gyration chamfer part of the inlet chamfer is obliquely arranged relative to the axis of the inlet throat, and the lower end opening of the inlet chamfer is arranged towards the direction of the outlet throat, a wider chamfer surface can be processed at the edge of one side of the inlet throat close to the outlet throat, meanwhile, the transition between the chamfer surface at the side and the bottom surface of the cylinder cover and the wall surface of the inlet throat is smoother, thereby reducing the kinetic energy loss when the air current flows through the inlet chamfer, being beneficial to guiding the inlet air current to the direction of the outlet throat, and forming effective tumble in the cylinder.

Therefore, on the basis of the existing diesel engine, the invention enables the rotation center line of the arc rotation chamfer part to be obliquely arranged relative to the axis of the air inlet throat and the lower end opening of the air inlet chamfer to be arranged towards the direction of the exhaust throat, so that most of the air inlet flow can enter the cylinder from one side of the air inlet throat close to the exhaust throat in an inclined mode, the tumble strength is favorably enhanced, the turbulent flow is favorably formed at the final stage of compression, and the heat efficiency of the gas engine is improved.

The invention has the following beneficial effects:

1) when the air inlet chamfer is machined, the chamfer structure biased towards the exhaust throat can be obtained only by arranging the rotary central line in an inclined manner, and compared with the prior art, the machining mode of the eccentric chamfer is further simplified, and the machining difficulty is reduced;

2) the invention can make the chamfer surface of the inlet chamfer close to one side of the exhaust throat wider, and make the transition between the inlet chamfer and the bottom surface of the cylinder cover smoother, thereby being more beneficial to reducing the kinetic energy loss of airflow and being beneficial to the airflow to form tumble.

The invention also provides a gas engine, which comprises the cylinder cover, and the cylinder cover has the technical effects, so that the gas engine using the cylinder cover also has the technical effects, and the details are not repeated.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the drawings without creative efforts.

FIG. 1 is a schematic view of an intake chamfer provided in an embodiment of the present invention;

FIG. 2 is a partial cross-sectional view of an air intake chamfer provided in accordance with an embodiment of the present invention;

FIG. 3 is a schematic diagram of the distribution structure of the intake throats and the exhaust throats provided by the embodiment of the invention;

FIG. 4 is a schematic diagram illustrating arrangement of two intake throats and a cylinder head intake port at different intervals according to an embodiment of the present invention;

FIG. 5 is a schematic view of an intake chamfer profile with a guide chamfer according to an embodiment of the present invention;

FIG. 6 is a schematic view of a first guiding chamfer profile shape according to an embodiment of the present invention;

FIG. 7 is a schematic view of a second guide chamfer profile shape provided by an embodiment of the present invention;

fig. 8 is a schematic view of a third guiding chamfer contour according to an embodiment of the present invention.

In fig. 1-8:

1 is a cylinder cover; 2 is an air inlet throat; 3, air inlet chamfering; 4 is an inlet valve seat ring; 5 is the axis of the air inlet throat; 6 is a gyration central line of the arc gyration chamfer part; 7 is an exhaust throat; 8 is a cylinder cover air inlet; 9 is the bottom surface of the cylinder cover; 21 is a first air inlet throat; 22 is a second air inlet throat; 23 is a first air inlet channel; 24 is a second air inlet channel; 31 is a circular arc rotary chamfer contour line; 32 is a guide chamfer contour line, and 33 is a circular arc transition chamfer contour line.

Detailed Description

One of the cores of the invention is to provide a cylinder cover, the structural design of which can enable the gas entering the cylinder to generate the tumble motion required by the gas engine, thereby improving the thermal efficiency of the gas engine.

The other core of the invention is to provide a gas engine based on the cylinder cover.

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.

Referring to fig. 1, fig. 1 is a schematic view of an intake chamfer according to an embodiment of the present invention.

The cylinder cover 1 provided by the embodiment of the invention comprises an air inlet throat 2 and an exhaust throat 7.

Wherein, the bottom hole of the air inlet throat 2 is provided with an air inlet chamfer 3, and the air inlet chamfer 3 comprises an arc rotary chamfer part, namely, the arc rotary chamfer part is a chamfer structure obtained by removing the material of the cylinder cover 1 with rotary characteristics and then processing. The turning center line of the circular arc turning chamfer (i.e. circular arc turning chamfer turning center line 6 in fig. 1) is arranged obliquely to the axis of the intake throat 2 (i.e. intake throat axis 5 in fig. 1) and the lower end opening of the intake chamfer 3 is arranged toward the exhaust throat 7. As shown in fig. 1, the arc-shaped rotation center line 6 of the rotation chamfer portion is inclined at an angle θ with respect to the inlet throat axis 5, and the intersection of the arc-shaped rotation center line 6 and the inlet throat axis 5 is located above the bottom hole of the inlet throat 2, preferably in the region between the upper port of the inlet valve seat 4 and the bottom hole of the inlet throat 2.

The cylinder cover 1 provided by the invention can be suitable for a two-valve engine or a multi-valve engine, namely, the number of the air inlet throat openings 2 can be one or two or three or more, the number of the exhaust throat openings 7 can also be one or two or more, which is not described in detail herein, if the air inlet throat openings 2 of the cylinder cover 1 are provided with a plurality of air inlet throat openings, the inclination angles of the circular arc rotary chamfer part rotary central line 6 of the air inlet throat opening 2 of each cylinder cover 1 relative to the air inlet throat opening axis 5 can be all the same, can also be different, or can be partially the same.

The working principle of the invention is as follows:

when a gas engine cylinder inhales, an inlet valve is opened, inlet airflow sequentially flows through an air inlet channel, the inlet valve, an inlet valve seat ring 4 and an inlet chamfer 3 and then enters the cylinder, because the arc rotary chamfer part rotary central line 6 of the inlet chamfer 3 is obliquely arranged relative to the inlet throat axis 5 and the lower end opening of the inlet chamfer 3 is arranged towards the direction of an exhaust throat 7, a wider chamfer surface can be processed at the edge of one side, close to the exhaust throat 7, of the inlet throat 2, so that the inlet airflow is guided towards the direction of the exhaust throat 7, meanwhile, the transition between the chamfer surface of the side and the cylinder cover bottom surface 9 and the wall surface of the inlet throat 2 is smoother, the kinetic energy loss of the airflow flowing through the inlet chamfer 3 is reduced, the inlet airflow is guided towards the direction of the exhaust throat 7, and effective tumble flow is formed in the cylinder.

Therefore, on the basis of the existing diesel engine, the invention can ensure that most of the intake airflow enters the cylinder from one side of the intake throat 2 close to the exhaust throat 7 obliquely and downwards by enabling the rotary central line 6 of the arc rotary chamfer part to be obliquely arranged relative to the axis 5 of the intake throat and enabling the lower end opening of the intake chamfer 3 to be arranged towards the direction of the exhaust throat 7, thereby being beneficial to enhancing the tumble intensity, being beneficial to forming turbulent flow at the final stage of compression and improving the thermal efficiency of the gas engine.

The chamfer structure with different longitudinal section shapes can be obtained according to different rotary processing surfaces, for example, after the material of the cylinder cover 1 is removed by adopting a conical rotary processing surface, the longitudinal section of the chamfer structure is a linear structure. Preferably, the longitudinal section of the inlet chamfer 3 is a straight line or a curved line. Further preferably, the longitudinal section of the air inlet chamfer 3 is designed to be in a curve shape, as shown in fig. 2, so that the phenomenon of flow separation of the air flow when the air flow passes through the air inlet chamfer 3 can be effectively prevented.

It is further preferred that the longitudinal section of the inlet chamfer 3 is a curve that is convex in the direction of the cylinder interior, as shown in fig. 2, in which case the chamfer surface that is convex in the cylinder prevents flow separation of the air stream as it passes through the chamfer.

Preferably, in the embodiment of the present invention, as shown in fig. 1, the angle θ of the rotation central line 6 of the circular arc rotation chamfer part inclining with respect to the inlet throat axis 5 satisfies 0 ° < θ ≦ 30 °, and specifically, the angle θ of the rotation central line 6 of the circular arc rotation chamfer part inclining with respect to the inlet throat axis 5 may be 5 ° or 10 ° or 20 ° or 30 °.

In a preferable scheme, the air inlet chamfer 3 further comprises a guiding chamfer part, the guiding chamfer part is connected to one side of the circular arc rotary chamfer part close to the exhaust throat 7, and the guiding chamfer part is convex towards the exhaust throat 7 relative to the circular arc rotary chamfer part. According to the scheme, the guide chamfer part is machined at one side edge of the arc-shaped rotary chamfer part close to the exhaust throat 7, so that the air inlet flow can be further converged and guided along the guide chamfer part, and the air flow can be accurately guided to flow towards the exhaust throat 7.

Preferably, the intersection line of the guide chamfer and the cylinder head bottom surface 9 is a guide chamfer contour line 32, the guide chamfer contour line 32 includes a broken line and/or a smooth curve, the intersection line of the circular arc gyration chamfer and the cylinder head bottom surface 9 is a circular arc gyration chamfer contour line 31, as shown in fig. 6 to 8, the guide chamfer contour line 32 in fig. 6 is a smooth curve, the guide chamfer contour line 32 in fig. 7 is a broken line shape composed of several line segments, and the guide chamfer contour line 32 in fig. 8 is a broken line shape formed by combining the line segments and the smooth curve.

Further preferably, the circular arc gyration chamfer and the guide chamfer are connected by a circular arc transition chamfer surface between two ends along the circumferential direction of the air inlet chamfer 3, and the curvature center of the circular arc transition chamfer surface is positioned at the outer side of the air inlet chamfer 3. With the arrangement, the inlet airflow is smoothly guided by the arc transition chamfer surface when flowing from the edge of the arc rotary chamfer part to the guide chamfer part, so that the energy loss of the airflow can be reduced.

Referring to fig. 5, the intersection line of the circular arc rotary chamfer part and the cylinder head bottom surface 9 is a circular arc rotary chamfer contour line 31, the intersection line of the guide chamfer part and the cylinder head bottom surface 9 is a guide chamfer contour line 32, the intersection line of the circular arc transition chamfer surface and the cylinder head bottom surface 9 is a circular arc transition chamfer contour line 33, the intersection point of the circular arc rotary chamfer part rotary center line 6 and the cylinder head bottom surface 9 is a reference point O, the diameter D1 of the circular arc rotary chamfer contour line 31 is 1.28-1.47 times of the inner diameter Dv of the intake valve seat ring, wherein the inner diameter Dv of the intake valve seat ring is the minimum diameter of the intake valve seat ring 4 and the intake valve sealing conical surface; the distance D2 between the two ends of the guide chamfer contour line 32 is 0.5-0.6 times of the inner diameter Dv of the intake valve seat ring, the farthest distance H between the guide chamfer contour line 32 and the reference point O is 0.55-0.65 times of the inner diameter Dv of the intake valve seat ring, and the radius R of the arc transition chamfer contour line 33 is 2-8 mm.

Preferably, when the cylinder head 1 is provided with a plurality of intake throats 2, each intake throat 2 may be connected with an intake passage, and each intake passage is arranged separately, i.e. the intake air flows in each intake passage are independent and do not interfere with each other. Or, when the cylinder head 1 is provided with a plurality of inlet throats 2, each inlet throats 2 is connected with an inlet channel, and each inlet channel is connected into a whole at one end far away from the inlet throats 2, that is, the inlet airflow firstly enters the inlet channel with the main front end and flows to each inlet throats 2 through each branch air channel when approaching the inlet throats 2.

When the cylinder cover 1 is provided with a plurality of air inlet throats 2, each air inlet throat 2 is respectively connected with an air inlet channel, and when the ends of the air inlet channels far away from the air inlet throat 2 are connected into a whole, the distances between the air inlet throat 2 and the air inlet 8 of the cylinder cover can be the same or different, in the embodiment shown in fig. 4, the cylinder head 1 includes a first intake throat 21 and a second intake throat 22, the first intake throat 21 is connected with a first intake channel 23, the second intake throat 22 is connected with a second intake channel 24, the first intake channel 23 and the second intake channel 24 are connected into a whole at one end far away from the first intake throat 21 and the second intake throat 22, the first intake channel 23 and the second intake channel 24 share a cylinder head intake port 8, and a distance L1 between the first intake throat 21 and the cylinder head intake port 8 is smaller than a distance L2 between the second intake throat 22 and the cylinder head intake port 8.

In order to further optimize the technical scheme, in the embodiment of the invention, the cylinder cover 1 is provided with the plurality of air inlet throats 2, and the air inlet chamfers 3 of at least two air inlet throats 2 are different, wherein the difference comprises the characteristics of the shape of the air inlet chamfers 3, the inclination angle theta of the gyration central line 6 of the circular arc gyration chamfer part relative to the axis 5 of the air inlet throats and the like.

It should be noted that the cylinder head intake port 8 is generally disposed on a side surface of the cylinder head 1, and of course, the cylinder head 1 provided in the embodiment of the present invention may also dispose the cylinder head intake port 8 on a top surface or a bottom surface of the cylinder head 1, so as to facilitate installation and arrangement of engines of different models.

Based on the cylinder head 1, the embodiment of the present invention further provides a gas engine, which includes the cylinder head 1 according to the above embodiment, and as the gas engine adopts the cylinder head 1 according to the above embodiment, please refer to the above embodiment for technical effects of the gas engine.

The embodiments in the present description are described in a progressive manner, each embodiment focuses on differences from other embodiments, and the same and similar parts among the embodiments are referred to each other.

The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.