1. The utility model provides a cylinder head, includes intake duct, air inlet throat and exhaust throat, its characterized in that, being close to of intake duct one section of air inlet throat is tumble direction air flue, tumble direction air flue arranges for the cylinder head bottom surface slope, be close to of tumble direction air flue a lateral wall face of cylinder head bottom surface is first wall, in the tumble direction air flue with another lateral wall face that first wall is relative is the second wall, be equipped with in the tumble direction air flue and be used for guiding the air current of admitting air to the water guide curved surface portion of exhaust throat direction motion, water guide curved surface portion is one of first overall arrangement structure, second overall arrangement structure and third overall arrangement structure, wherein:

the first layout structure is as follows: at least two arc-shaped pit surfaces which are sunken towards the bottom surface of the cylinder cover relative to the first wall surface are distributed on the first wall surface along the air inlet direction;

the second layout structure is as follows: a first flow guide curved surface part and a second flow guide curved surface part are arranged in the tumble guide air passage, the first flow guide curved surface part is an arc-shaped pit surface which is arranged on the first wall surface and is sunken towards the bottom surface of the cylinder cover relative to the first wall surface, the second wall surface which is arranged opposite to the first flow guide curved surface part forms the second flow guide curved surface part, and the second flow guide curved surface part is a smooth curved surface which is gradually close to the exhaust throat opening along the air inlet direction;

the third layout structure is as follows: the cylinder cover comprises a first wall surface and a second wall surface, wherein the first wall surface is provided with a first flow guide curved surface part and a second flow guide curved surface part along the air inlet direction, the first flow guide curved surface part is an arc-shaped pit surface which is concave towards the bottom surface direction of the cylinder cover relative to the first wall surface, the second flow guide curved surface part is a flow guide protruding part which is positioned above the air inlet throat, the axial projection of the flow guide protruding part on the upper end surface of the air inlet throat is a protruding projection, the protruding projection is positioned on the inner side of the air inlet throat and forms a protruding area which protrudes from the edge of the upper end surface of the air inlet throat to the center of the air inlet throat along the radial direction, and the width of the middle part of the protruding projection is larger than the width of the two ends of the protruding projection.

2. The cylinder head according to claim 1, wherein when the air guiding curved surface portion is the first layout structure, a lower side edge of a last one of the arc-shaped recess surfaces, which is distributed in an intake direction on the first wall surface, is connected to an upper side edge of the intake throat.

3. The cylinder cover according to claim 1 or 2, wherein when the flow guide curved surface portion is the first layout structure, a first arc-shaped pit surface and a second arc-shaped pit surface are distributed on the first wall surface along the air inlet direction, the distance between the deepest position of the first arc-shaped pit surface relative to the first wall surface recess and the axis of the air inlet throat is 0.8-2.9 times of the inner diameter of the intake valve seat ring, and the distance between the deepest position of the second arc-shaped pit surface relative to the first wall surface recess and the axis of the air inlet throat is 0.2-1.6 times of the inner diameter of the intake valve seat ring.

4. The cylinder head of claim 1, wherein when the flow guide curved surface portion is the second layout structure, a lower side edge of the first flow guide curved surface portion and a lower side edge of the second flow guide curved surface portion are both contiguous with an upper side edge of the intake throat.

5. The cylinder head according to claim 1 or 4, wherein when the flow guide curved surface portion is the second layout structure, a plane passing through both the axis of the intake throat and the axis of the exhaust throat is a vertical feature surface, an intersection of the second wall surface and the vertical feature surface is a second wall surface feature line, and the second wall surface feature line is a straight line inclined with respect to the bottom surface of the cylinder head.

6. The cylinder head of claim 5, wherein the maximum distance between the second wall surface and the bottom surface of the cylinder head is 0.8 to 1.5 times the inner diameter of the intake valve seat ring, and the maximum distance between the upper side edge of the first flow guiding curved surface part and the axis of the intake throat is 0.8 to 2 times the inner diameter of the intake valve seat ring.

7. The cylinder head of claim 5, wherein the second wall face feature line is angled 40 ° -80 ° from the cylinder head floor.

8. The cylinder head according to claim 1 or 4, wherein when the flow guide curved surface portion is the second layout structure, a plane parallel to both the axis of the intake throat and the axis of the exhaust throat is a vertical feature surface, an intersection of the second wall surface and the vertical feature surface is a second wall surface feature line, and the second wall surface feature line is an arc line that protrudes toward the bottom surface of the cylinder head.

9. The cylinder head of claim 8, wherein a projection of the second wall surface on the bottom surface of the cylinder head has a length of 0.5 to 3 times an inner diameter of an intake valve seat ring.

10. The cylinder head of claim 1, wherein the number of the intake throats is one, two or three, and each intake throat is correspondingly connected with one intake channel.

11. The cylinder head of claim 1, wherein the number of intake ports is two or three, and each of the intake ports is arranged separately.

12. The cylinder head of claim 1, wherein the number of intake ports is two or three, and the flow guide curved surface portions in at least two of the intake ports are different.

13. The cylinder head of claim 1, wherein the intake port of the intake passage is disposed at a side surface or a top surface or a bottom surface of the cylinder head.

14. A gas engine, characterized by comprising a cylinder head according to any one of claims 1 to 13.

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 the cylinder head of the engine is required to organize the air flow to generate a sufficient swirl ratio during the 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 improved, and the improvement of the tumble strength in the cylinder can be beneficial to forming turbulence at the end stage of compression, 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, an object of the present invention is to provide a cylinder head, which generates a tumble motion required by a gas engine by changing an air inlet structure based on an existing diesel engine, and can improve a tumble strength, thereby improving a 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:

the utility model provides a cylinder head, includes intake duct, air inlet throat and exhaust throat, being close to of intake duct one section of air inlet throat is the tumble direction air flue, the tumble direction air flue is arranged for cylinder head bottom surface slope, being close to of tumble direction air flue a lateral wall face of cylinder head bottom surface is first wall, in the tumble direction air flue with another lateral wall face that first wall is relative is the second wall, be equipped with in the tumble direction air flue and be used for guiding the air current that admits air to the water conservancy diversion curved surface portion of exhaust throat direction motion, the water conservancy diversion curved surface portion is one of first layout structure, second layout structure and third layout structure, wherein:

the first layout structure is as follows: at least two arc-shaped pit surfaces which are sunken towards the bottom surface of the cylinder cover relative to the first wall surface are distributed on the first wall surface along the air inlet direction;

the second layout structure is as follows: a first flow guide curved surface part and a second flow guide curved surface part are arranged in the tumble guide air passage, the first flow guide curved surface part is an arc-shaped pit surface which is arranged on the first wall surface and is sunken towards the bottom surface of the cylinder cover relative to the first wall surface, the second wall surface which is arranged opposite to the first flow guide curved surface part forms the second flow guide curved surface part, and the second flow guide curved surface part is a smooth curved surface which is gradually close to the exhaust throat opening along the air inlet direction;

the third layout structure is as follows: the cylinder cover comprises a first wall surface and a second wall surface, wherein the first wall surface is provided with a first flow guide curved surface part and a second flow guide curved surface part along the air inlet direction, the first flow guide curved surface part is an arc-shaped pit surface which is concave towards the bottom surface direction of the cylinder cover relative to the first wall surface, the second flow guide curved surface part is a flow guide protruding part which is positioned above the air inlet throat, the axial projection of the flow guide protruding part on the upper end surface of the air inlet throat is a protruding projection, the protruding projection is positioned on the inner side of the air inlet throat and forms a protruding area which protrudes from the edge of the upper end surface of the air inlet throat to the center of the air inlet throat along the radial direction, and the width of the middle part of the protruding projection is larger than the width of the two ends of the protruding projection.

Preferably, when the diversion curved surface portion is the first layout structure, the lower side edge of the last arc-shaped pit surface distributed along the air inlet direction on the first wall surface is connected with the upper side edge of the air inlet throat.

Preferably, when the diversion curved surface portion is of the first layout structure, a first arc-shaped pit surface and a second arc-shaped pit surface are distributed on the first wall surface along the air inlet direction, the distance between the deepest position of the first arc-shaped pit surface relative to the first wall surface recess and the axis of the air inlet throat is 0.8-2.9 times of the inner diameter of the intake valve seat ring, and the distance between the deepest position of the second arc-shaped pit surface relative to the first wall surface recess and the axis of the air inlet throat is 0.2-1.6 times of the inner diameter of the intake valve seat ring.

Preferably, when the flow guiding curved surface portion is in the second layout structure, the lower side edge of the first flow guiding curved surface portion and the lower side edge of the second flow guiding curved surface portion are both connected with the upper side edge of the air inlet throat.

Preferably, when the flow guide curved surface portion is in the second layout structure, a plane passing through an axis of the intake throat and an axis of the exhaust throat is a vertical feature surface, an intersection line of the second wall surface and the vertical feature surface is a second wall surface feature line, and the second wall surface feature line is a straight line inclined relative to the bottom surface of the cylinder head.

Preferably, the maximum distance between the second wall surface and the bottom surface of the cylinder cover is 0.8-1.5 times of the inner diameter of the intake valve seat ring, and the maximum distance between the upper side edge of the first flow guide curved surface part and the axis of the intake throat opening is 0.8-2 times of the inner diameter of the intake valve seat ring.

Preferably, the included angle between the second wall surface characteristic line and the bottom surface of the cylinder cover is 40-80 degrees.

Preferably, when the flow guide curved surface portion is the second layout structure, a plane parallel to the axis of the intake throat and the axis of the exhaust throat is a vertical feature surface, an intersection line of the second wall surface and the vertical feature surface is a second wall surface feature line, and the second wall surface feature line is an arc line protruding towards the bottom surface of the cylinder head.

Preferably, the projection length of the second wall surface on the bottom surface of the cylinder head is 0.5-3 times of the inner diameter of the intake valve seat ring.

Preferably, when the flow guide curved surface portion is in the second layout structure, the minimum distance between the flow guide protruding portion and the axis of the intake throat is greater than 0 and less than or equal to 0.5 times of the inner diameter of the intake valve seat ring, the deepest portion of the first flow guide curved surface portion, which is recessed relative to the first wall surface, is a pit position point, the distance between the pit position point and the axis of the intake throat is 0.5-3 times of the inner diameter of the intake valve seat ring, and the distance between the pit position point and the bottom surface of the cylinder head is greater than 0 and less than or equal to the inner diameter of the intake valve seat ring.

Preferably, the number of the air inlet throats is one or two or three, and each air inlet throat is correspondingly connected with one air inlet channel.

Preferably, the number of the air inlet channels is two or three, and each air inlet channel is arranged in a separated mode.

Preferably, the number of the air inlet channel is two or three, and at least two of the guide curved surface parts in the air inlet channel are different.

Preferably, an intake port of the intake passage is disposed at a side surface or a top surface or a bottom surface of the cylinder head.

The cylinder cover comprises an air inlet channel, an air inlet throat and an air outlet throat, wherein a section of the air inlet channel close to the air inlet throat is a tumble guiding air channel, and the wall surface of the tumble guiding air channel is provided with at least two guide curved surface parts for guiding the movement of intake air flow towards the air outlet throat.

The working principle of the invention is as follows:

when the engine cylinder breathes in, the (air) intake valve is opened, the air current that admits air in the intake duct flows through in proper order and enters into the cylinder combustion chamber from the inlet throat after each water conservancy diversion curved surface portion, make the air current that admits air move towards exhaust throat direction under the water conservancy diversion effect of each water conservancy diversion curved surface portion, thereby the air current of flow direction exhaust throat one side has been strengthened and the air current of inlet throat one side has been reduced, this both sides air current forms the big scale tumble motion more easily after getting into the cylinder, and then reinforcing tumble intensity, be favorable to forming the torrent at compression final stage, promote gas engine's thermal efficiency.

Therefore, on the basis of the existing diesel engine, the plurality of guide curved surface parts are designed at the downstream of the air inlet channel, so that the intake air flow generates the tumble effect required by the gas engine, and further the tumble strength and the heat efficiency of the gas engine are improved.

The invention also provides a gas engine comprising the cylinder cover. The derivation process of the beneficial effects generated by the gas engine is substantially similar to the derivation process of the beneficial effects brought by the cylinder cover, and therefore, the description is omitted.

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 a first cylinder head configuration in an embodiment of the present invention;

FIG. 2 is a schematic view of a second cylinder head configuration in an embodiment of the present invention;

FIG. 3 is a schematic view of a third cylinder head configuration in an embodiment of the present invention;

FIG. 4 is a schematic view of a fourth cylinder head configuration in an embodiment of the present invention;

FIG. 5 is a schematic diagram of a projected projection and theoretical intake air flow port in a fourth cylinder head configuration in accordance with an embodiment of the present invention;

FIG. 6 is a bottom view of the bottom surface of the cylinder head in a fourth cylinder head configuration in accordance with an embodiment of the present invention.

The meaning of the various reference numerals in figures 1 to 6 is as follows:

1-air inlet channel, 2-air inlet throat, 3-air cylinder, 4-first wall surface, 5-second wall surface, 6-cylinder cover bottom surface, 7-flow guide protrusion part, 21-air inlet valve seat ring, 22-air inlet throat axis, 23-theoretical air inlet flow port, 24-connecting line of air inlet throat center and exhaust throat center, 41-first arc-shaped pit surface, 42-second arc-shaped pit surface, 43-first flow guide curved surface part, 51-second wall surface characteristic line, 71-projection, 72-connecting line of two ends, 73-projection direction line and 8-exhaust throat center.

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.

Referring to fig. 1 to 4, fig. 1 to 4 are schematic structural views of a first cylinder head to a fourth cylinder head according to an embodiment of the present invention.

The invention provides a cylinder cover which comprises an air inlet channel 1, an air inlet throat 2 and an exhaust throat (not shown in the figure), wherein one section of the air inlet channel 1 close to the air inlet throat 2 is a tumble guiding air channel, and the wall surface of the tumble guiding air channel is provided with at least two guide curved surface parts for guiding the movement of intake air flow towards the direction of the exhaust throat. The flow guide curved surface part can be a part or all of the wall surface of the air inlet channel, and can also be designed to be a concave pit curved surface or a convex curved surface which is positioned on the local wall surface of the air inlet channel, and when the air flow flows through the flow guide curved surface part, the flow guide curved surface part can guide and cast the air flow.

The working principle of the invention is as follows:

when the engine cylinder breathes in, the (air) intake valve is opened, the air current that admits air in the intake duct 1 flows through in proper order and enters into cylinder 3 from air inlet throat 2 behind each water conservancy diversion curved surface portion, make the air current that admits air move towards air exhaust throat direction under the water conservancy diversion effect of each water conservancy diversion curved surface portion, thereby the air current of flow direction air exhaust throat one side has been strengthened and the air current of air inlet throat 2 one side has been reduced, this both sides air current forms large scale tumble motion after getting into cylinder 3 more easily, and then reinforcing tumble intensity, be favorable to forming the torrent at compression final stage, promote gas engine's thermal efficiency.

Therefore, on the basis of the existing diesel engine, the plurality of guide curved surface parts are designed at the downstream of the air inlet 1, so that the intake airflow generates the tumble effect required by the gas engine, and further the tumble strength and the heat efficiency of the gas engine are improved.

It should be noted that, in this embodiment, the air inlet of the air inlet channel 1 is opened on the outer side of the cylinder head, the other end of the air inlet channel 1 is an air inlet throat 2, and in the air inlet direction, the tumble guide air channel is located at the downstream of the air inlet channel 1, wherein the tumble guide air channel may be designed in various arrangement forms, such as being obliquely arranged or vertically arranged with respect to the bottom surface 6 of the cylinder head. In a preferred embodiment, the tumble flow guide air passage is arranged obliquely with respect to the cylinder head bottom surface 6, and the tumble flow guide air passage gradually approaches the intake throat 2 and the exhaust throat in the intake direction, as shown in fig. 1 to 4, one side wall surface of the tumble flow guide air passage that is close to the cylinder head bottom surface 6 is a first wall surface 4, and the other side wall surface of the tumble flow guide air passage that is opposite to the first wall surface 4 is a second wall surface 5. In the present invention, at least one flow guiding curved surface portion may be provided on both the first wall surface 4 and the second wall surface 5, or at least two flow guiding curved surface portions may be provided only on the first wall surface 4.

Specifically, a flow guiding curved surface part for guiding the intake airflow to move towards the exhaust throat is arranged in the tumble guiding air passage, and the flow guiding curved surface part is one of a first layout structure, a second layout structure and a third layout structure.

The first layout structure is that at least two arc-shaped pit surfaces which are sunken towards the bottom surface 6 of the cylinder cover relative to the first wall surface 4 are distributed on the first wall surface 4 along the air inlet direction. The arc-shaped pit surface can generate a throwing effect on the intake air flow, namely, the intake air flow firstly enters the bottom of the pit from the upper side edge of the arc-shaped pit surface when flowing through the arc-shaped pit surface, then flows out from the lower side edge of the arc-shaped pit surface, when the air flow flows out from the lower side edge, because the inner diameter of the air inlet channel corresponding to the lower side edge from the bottom of the pit is reduced, therefore, the air flow is accelerated, and meanwhile, the lower half section of the arc-shaped pit surface can throw the air flow to the second wall surface 5 at the opposite side, so that the intake air flow mainly flows along the second wall surface 5 after flowing out of the arc-shaped pit surface, and the second wall surface 5 is closer to the exhaust throat, so that, when the intake air flows into the cylinder 3 from the intake throat 2, mainly enters the combustion chamber from a gap at one side close to the exhaust throat, and the main air inlet direction of the inlet airflow is shown by an arrow at the inlet throat 2 in figure 1. In this scheme, because set up a plurality of arc pit faces of arranging along the direction of admitting air on the first wall 4, consequently, can produce the effect of accelerating many times and direction projection to the air current that admits air to the air current of further reinforcing second wall 5 side flows. After most of the intake airflow enters the cylinder 3 from the gap on the side close to the exhaust throat, the intake airflow is blocked by the wall surface of the cylinder 3, so that the tumble strength is more favorably enhanced, and the tumble direction is shown by an arc arrow in the cylinder 3 in fig. 1.

Further preferably, the lower side edge of the last arc-shaped pit surface distributed along the air inlet direction on the first wall surface 4 is connected with the upper side edge of the air inlet throat 2, so that the arc-shaped pit surface at the tail end of the tumble guiding air passage can cast airflow to one end, closest to the air inlet throat 2, of the second wall surface 5, when the air inlet valve is opened, most of the intake airflow can enter the air cylinder 3 from a gap, facing one side of the air inlet throat 2, and then tumble strength in the air cylinder 3 is further enhanced.

In a specific embodiment, as shown in fig. 1, a first arc-shaped pit surface 41 and a second arc-shaped pit surface 42 are distributed on the first wall surface 4 along the air intake direction, the distance (first pit distance L1) between the deepest position of the first arc-shaped pit surface 41, which is recessed relative to the first wall surface 4, and the axis (the air intake throat axis 22 shown in fig. 1) of the air intake throat 2 is 0.8-2.9 times of the inner diameter (the minimum diameter of the air intake valve seat ring 21 and the air intake valve sealing conical surface) D of the air intake valve seat ring, and specifically, the first pit distance L1 may be 0.8 times, 1.2 times, 1.6 times, 2.1 times, 2.5 times or 2.9 times of the inner diameter D of the air intake valve seat ring. The distance (second pit distance L2) between the deepest position of the second arc-shaped pit surface 42, which is recessed relative to the first wall surface 4, and the inlet throat axis 22 is 0.2-1.6 times of the inlet valve seat ring inner diameter D, and specifically, the second pit distance L2 may be 0.2 times, 0.8 times, 1.2 times or 1.6 times of the inlet valve seat ring inner diameter D. The air current is thrown tentatively behind first arc pit face 41, and the air current after throwing has the trend of getting back to first wall 4 after the extrusion of second wall 5, and this scheme is through the position of two arc pit faces on the rational arrangement first wall 4 for the air current can move to second arc pit face 42 after the extrusion of second wall 5, thereby is thrown once more, and then strengthens the generating strength of tumble motion.

The second layout structure includes a first flow guiding curved surface portion 43 and a second flow guiding curved surface portion, the first flow guiding curved surface portion 43 is an arc-shaped concave pit surface which is arranged on the first wall surface 4 and is concave towards the cylinder cover bottom surface 6 relative to the first wall surface 4, and the second wall surface 5 arranged opposite to the first flow guiding curved surface portion 43 forms a second flow guiding curved surface portion, namely, the second wall surface 5 opposite to the first flow guiding curved surface portion 43 is the second flow guiding curved surface portion, and the second flow guiding curved surface portion is a smooth curved surface which is gradually close to the exhaust throat along the air inlet direction. In the scheme, the arc-shaped concave pits are used for guiding and projecting the air inlet flow, and the smooth second flow guide curved surface part gradually close to the exhaust throat is used for guiding the air inlet flow, so that most of the air inlet flow enters the cylinder 3 from a gap on one side, close to the exhaust throat, of the air inlet throat 2, and the tumble strength in the cylinder 3 is improved.

Preferably, when water conservancy diversion curved surface portion is the second overall arrangement structure, the downside border of first water conservancy diversion curved surface portion 43 and the downside border of second water conservancy diversion curved surface portion all meet with the upside border of intake throat 2, so set up, make the arc pit face can be thrown the air current to the one end that second water conservancy diversion curved surface portion is closest to intake throat 2, the junction between the upside border of second water conservancy diversion curved surface portion and intake throat 2 (namely the upside border that intake throat 2 is close to exhaust throat one side) does not have other bending surface structures, the kinetic energy loss of gas flow has been reduced, when the (air) intake valve is opened, just can make most intake airflow enter into cylinder 3 from the gap of intake throat 2 towards exhaust throat one side, and then further strengthen the tumble intensity in the cylinder 3.

As shown in fig. 2, in a specific embodiment, when the flow guiding curved surface portion is in the second layout structure, a plane passing through the axis 22 of the intake throat and the axis of the exhaust throat is a vertical characteristic surface, an intersection line of the second wall surface 5 and the vertical characteristic surface is a second wall surface characteristic line 51, and since an extending direction of a projection of the tumble flow guide duct on the bottom surface 6 of the cylinder head is consistent with a direction of the intake throat 2 toward the corresponding exhaust throat, the extending direction of the second wall surface characteristic line 51 is the extending direction of the second wall surface 5 of the tumble flow guide duct. In this embodiment, the second wall surface characteristic line 51 is a straight line inclined with respect to the cylinder head bottom surface 6, that is, in the air intake direction, the second flow guiding curved surface portion extends in a direction in which the straight line descends, so that the airflow projected by the arc-shaped pit surface of the first wall surface 4 further flows in a direction in which the straight line descends, and the intake airflow rapidly descends before entering the intake throat 2, thereby further improving the tumble strength while reducing the energy loss of the gas flow.

Further preferably, the maximum distance between the second wall surface 5 and the cylinder head bottom surface 6 (i.e., the height H1 of the second wall surface characteristic line 51 shown in fig. 2) is 0.8 to 1.5 times the inner diameter D of the intake valve seat, and the maximum distance L3 between the upper edge of the first flow guide curved surface portion 43 and the intake throat axis 22 is 0.8 to 2 times the inner diameter D of the intake valve seat.

Further preferably, the included angle between the second wall surface characteristic line 51 and the cylinder head bottom surface 6 is 40-80 degrees.

As shown in fig. 3, in another embodiment, when the flow guiding curved surface portion has the second layout structure, the following situation may be adopted: meanwhile, a plane passing through the axis 22 of the air inlet throat and the axis of the exhaust throat is a vertical characteristic surface, the intersection line of the second wall surface 5 and the vertical characteristic surface is a second wall surface characteristic line 51, and as the extending direction of the projection of the tumble flow guide air passage on the bottom surface 6 of the cylinder cover is consistent with the direction of the air inlet throat 2 towards the corresponding exhaust throat, the extending direction of the second wall surface characteristic line 51 is the extending direction of the second wall surface 5 of the tumble flow guide air passage. In this embodiment, the second wall surface characteristic line 51 is an arc line protruding toward the cylinder head bottom surface 6, so that the central line of the entire tumble flow guide air passage protrudes toward the cylinder head bottom surface 6, that is, the tumble flow guide air passage protrudes and bends toward the cylinder head bottom surface 6 as a whole. So set up, the first section of second water conservancy diversion curved surface portion just can guide the air current that admits air to contralateral first water conservancy diversion curved surface portion 43 in, the air current that throws out by first water conservancy diversion curved surface portion 43 drops to inlet throat mouth 2 along the second water conservancy diversion curved surface portion's second section fast again, thereby aggravate the trend that the air current of admitting air moved to exhaust throat mouth direction, consequently, this scheme can make more gas guide to the arc pit of first wall 4 in, and can further improve tumble strength when reducing the energy loss of gas flow.

More preferably, the projected length L4 of the second wall surface 5 on the cylinder head bottom surface 6 is 0.5 to 3 times the intake valve seat inner diameter D, and specifically, the projected length L4 may be 0.5 times, or 1 times, or 1.5 times, or 2 times, or 3 times the intake valve seat inner diameter D.

As shown in fig. 4, in another specific embodiment, when the air guiding curved surface portion has the third layout structure, the third layout structure is: a first flow guiding curved surface part 43 and a second flow guiding curved surface part are distributed on the first wall surface 4 along the air inlet direction, the first flow guiding curved surface part 43 is an arc-shaped pit surface which is concave towards the direction of the bottom surface 6 of the cylinder cover relative to the first wall surface 4, the second flow guiding curved surface part is a flow guiding protruding part 7 which is positioned above the air inlet throat 2, the axial projection of the flow guiding protruding part 7 on the upper end surface of the air inlet throat 2 is a protruding projection 71, the protruding projection 71 is positioned on the inner side of the air inlet throat 2 and forms a protruding area which protrudes from the edge of the upper end surface of the air inlet throat 2 to the center of the air inlet throat 2 along the radial direction, and the width of the middle part of the protruding projection 71 in the circumferential direction of the air inlet throat 2 is larger than the width of the two ends of the protruding projection, as shown in fig. 5. Specifically, the upper edge of the flow guide protrusion 7 is connected to the lower edge of the first flow guide curved surface portion 43, and the lower edge of the flow guide protrusion 7 is connected to the upper edge of the air inlet throat 2. In this scheme, after the air current that admits air flows through first water conservancy diversion curved surface portion 43, arc pit face casts the air current to offside second wall 5, the water conservancy diversion bulge 7 of arc pit face low reaches further makes the air current to 5 direction extrusions of second wall to the air current of flow direction exhaust throat mouth direction has been strengthened, the air current of exhaust throat mouth one side is kept away from to inlet throat mouth 2 has been reduced, this both sides air current forms stronger tumble motion after getting into cylinder 3, thereby satisfy gas engine's combustion demand.

Preferably, the minimum distance L6 of the guide projection 7 from the inlet throat axis 22 is greater than 0 and equal to or less than 0.5 times the inlet valve seat insert inner diameter D, specifically, the minimum distance L6 may be 0.1 times, or 0.2 times, or 0.3 times, or 0.4 times, or 0.5 times the inlet valve seat insert inner diameter D. The deepest part of the first flow guiding curved surface part 43 recessed relative to the first wall surface 4 is a recessed position point, the distance L5 between the recessed position point and the inlet throat axis 22 is 0.5-3 times of the inlet valve seat ring inner diameter D, specifically, the distance L5 may be 0.5 times, 0.6 times, 0.7 times, 0.8 times, 0.9 times, 1 times, 1.1 times, 1.2 times, 1.3 times, 1.4 times, 1.5 times, 1.6 times, 1.7 times, 1.8 times, 1.9 times, 2 times, 2.5 times, or 3 times of the inlet valve seat ring inner diameter D, the distance H2 between the recessed position point and the cylinder head bottom surface 6 is greater than 0 and less than or equal to the inlet valve seat ring inner diameter D, specifically, the distance H2 may be 0.1 times, 0.2 times, 0.3 times, 0.4 times, 0.5 times, 0.6 times, 0.7 times, 0.8 times, or 0.9 times of the inlet valve seat ring inner diameter D.

It should be noted that the flow guiding protrusion 7 in this embodiment is used to extrude a part of the air flow toward the exhaust throat before the intake air flow enters the intake throat 2, and the flow guiding protrusion 7 capable of achieving the above function may be designed in various structural shapes, for example, one side edge of the flow guiding protrusion 7 facing the center of the intake throat is designed to be an arc shape, a straight shape, a broken line shape or other curved structures. Preferably, the projection in this solution is a crescent-shaped area, and the concave side of the crescent-shaped area is arranged toward the center of the intake throat 2, i.e. one side edge of the flow guiding protrusion 7 toward the center of the intake throat is designed into a concave arc shape.

It should be noted that the flow guide protrusion 7 specifically includes an upper flow guide surface and a lower processing surface, the juncture of the upper flow guide surface and the lower processing surface is the edge of the flow guide protrusion 7 protruding toward the center of the air inlet throat, the lower processing surface is the processing surface formed after partial material of the cylinder head main body is removed by the flow guide protrusion processing characteristics, the flow guide protrusion processing characteristics specifically can adopt casting processing, rotary cutting processing and the like, and according to different structures of the flow guide protrusion 7, the lower processing surface specifically can be designed as a rotary processing surface, or a plurality of planes connected in sequence, or other curved surface structures and the like. Preferably, the lower processing surface in this scheme is a rotary processing surface surrounding a processing axis, the processing axis may be designed to be coincident with, parallel to, or inclined relative to the air inlet throat axis 22, and a generatrix of the rotary processing surface is a straight line, a broken line, or a curve. The rotary processing surface removes partial material of the cylinder head body to form the flow guide bulge 7.

It should be noted that, the rotary processing surface may be designed into various different tapered surface structures according to different bus shapes, and preferably, the rotary processing surface in this embodiment is a conical processing surface, a processing axis of the conical processing surface coincides with the air inlet throat axis 22, and a vertex of the conical processing surface is located above the air inlet throat 2. The concrete shape of the flow guide protruding part 7 depends on the size of the conical angle of the conical processing surface, and the larger the conical angle is, the sharper the flow guide protruding part 7 is. Preferably, the value range of the cone angle of the conical processing surface in the scheme is 60-160 degrees, and in the range, the guide protrusion part 7 can be ensured to have a sharp enough angle, so that the flow velocity mutation and the extrusion effect on the air inlet flow are further enhanced.

The maximum flow port formed by the rotary machined surface in the upper end circular surface of the intake throat 2 is the theoretical intake flow port 23, that is, the theoretical intake flow port 23 is formed by the axial projection of the circular contour formed by the conical bottom of the rotary machined surface after the material of the cylinder head body is removed in the upper end circular surface of the intake throat 2. When the processing axis of the rotary processing surface is coincident with or parallel to the axis of the air inlet throat 2, the theoretical air inlet flow port 23 is a circular flow port; when the machining axis of the rotary machined surface and the axis of the intake throat 2 are arranged relatively obliquely, the theoretical intake air flow port 23 is an elliptical flow port. Theoretical equivalent diameter of inlet flow port 23 is D₁The inner diameter of the inlet valve seat ring (the minimum diameter of the inlet valve seat ring and the inlet valve sealing conical surface) is D, and in the scheme, D is₁The relationship between D and D satisfies: d₁ = 0.85D-D, and D is₁When the D is 85% -100%, the circulation capacity and the tumble effect can be in balanced fit, namely, the tumble effect can be obviously achieved under the condition that the influence on the circulation capacity is minimum.

Referring to fig. 5, the total area of the theoretical intake air flow port 23 is S3, the area of the projected projection 71 is S1, and the flow guide protrusion 7 prevents partial airflow from passing through, so the area of the opening at the lower end of the tumble flow guide air passage for actual circulating airflow (i.e., the actual intake air flow port area S2 shown by the shaded portion in fig. 5) is equal to the total area S3 of the theoretical intake air flow port 23 minus the area S1 of the projected projection 71, i.e., the relationship of S1, S2, and S3: s3= S1+ S2.

The larger the area S1 of the projected projection 71, the more pronounced the effect of the flow guide projection 7 in blocking the air flow, and thus the greater the degree of squeezing of the air flow, i.e., the more pronounced the increase in the air flow velocity, the greater the intensity of the generated tumble flow. In order to balance the tumble effect and the air passage flow capacity, the area S1 of the projected projection 71 is designed to be 15% -50% of the area S3 of the theoretical intake air flow port 23, namely, the space between S1 and S3 satisfies the following conditions: S1/S3=0.15~ 0.5.

Preferably, a connecting line between a midpoint of a connecting line 72 (a connecting line between two end points P1 and P2, as shown in fig. 5) of two ends of the projection 71 and the center of the intake throat is a projection direction line 73, an included angle between a connecting line 24 between the center of the intake throat and the center of the exhaust throat and the projection direction line 73 is a projection direction angle β, as shown in fig. 6, the projection direction angle β in the scheme is in a range of 0 ° to 45 °, and by such arrangement, the projecting side edge of the flow guide projection 7 can be arranged towards the direction of the adjacent exhaust throat, so that the large-scale tumble motion is controlled to fill the whole cylinder as much as possible. Wherein, the connecting line 24 of the inlet throat center and the exhaust throat center refers to the connecting line of the center of the inlet throat 2 and the exhaust throat center 8, as shown in fig. 6.

Preferably, the convex projection 71 spans an arc angle θ of 90 ° -220 ° in the upper end face of the inlet throat 2. This feature defines the extent of the span of the flow directing projection 7 in the cross-section of the tumble flow directing air passage.

It should be noted that the cylinder head provided by the present invention may be applicable to a two-valve engine or a multi-valve engine, that is, the number of the intake throats 2 may be one or two or three or more, correspondingly, each intake throat 2 is correspondingly connected with one intake channel 1, and the number of the exhaust throats may also be one or two or more, which is not described herein again.

It should be noted that, for a cylinder head having two or three or more intake throats 2, the number of intake ports 1 is two or three or more, the respective intake ports 1 may be arranged to be separated from each other, or upstream portions of the respective intake ports 1 (i.e., an intake section located upstream of the tumble guide passage, a section near the intake port) may be communicated with each other to form an overall intake section.

It should be noted that, when the number of the intake ducts 1 in the present invention is two, three, or more, the flow guiding curved surface portion in each intake duct 1 may adopt the same structure or arrangement, or may adopt different structures or arrangements, for example, for a cylinder head structure having two intake ducts 1, two intake ducts 1 are designed to be asymmetric structures, two arc-shaped concave pit surfaces may be provided on the first wall surface 4 in the tumble guiding air duct in one intake duct 1, one arc-shaped concave pit surface may be provided on the first wall surface 4 in the tumble guiding air duct in the other intake duct 1, and the extension direction line of the second wall surface 5 is designed to be an arc line protruding toward the cylinder head bottom surface 6, as shown in fig. 3.

It should be noted that the intake port of the intake passage 1 is generally disposed on the side surface of the cylinder head, and of course, the intake port of the intake passage 1 may also be disposed on the top surface or the bottom surface of the cylinder head in the cylinder head provided by the invention, thereby facilitating the installation and arrangement of engines of different models.

The invention also provides a gas engine comprising the cylinder cover. The derivation process of the beneficial effects generated by the gas engine is substantially similar to the derivation process of the beneficial effects brought by the cylinder cover, and therefore, the description is omitted.

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.