CN117948214A - Cooling mechanism of cylinder - Google Patents

Abstract

The invention relates to a cooling mechanism of a cylinder, which is provided with a cylinder body and a cylinder head assembled on the cylinder body; the cylinder head is internally provided with a water jacket for cooling water flow; the cylinder head is provided with a cooling water outlet and a cooling water inlet which are oppositely arranged at opposite sides and communicated with the outside; the water jacket is provided with a water inlet guide passage communicated with the cooling water inlet and a water outlet converging passage connected with the cooling water outlet; the water inlet guide channel is connected with a first annular water channel and a second annular water channel; the other sides of the first annular water channel and the second annular water channel are connected with the water outlet converging channel; therefore, the flow velocity difference between the first annular water channel and the second annular water channel can be reduced, and the cooling and heat dissipation uniform effect of the cylinder head can be improved.

Description

Cooling mechanism of cylinder

Technical Field

The invention relates to a cooling mechanism of a cylinder, in particular to a cooling mechanism of a cylinder, which can improve the effect of uniform cooling and heat dissipation of the whole cylinder head.

Background

As shown in fig. 1, the water-cooled internal combustion engine has a good heat dissipation effect in the cylinder part of the engine; a water channel for cooling water to flow is arranged in a cylinder head of the cylinder part, and the water channel for cooling water to flow is called a water jacket 1; the water jacket 1 has an inlet portion 11 and an outlet portion 12, and a first flow passage 13 and a second flow passage 14 between the inlet portion 11 and the outlet portion 12; the water inlet part 11 is positioned on the exhaust side of the engine, the water outlet part 12 is positioned on the air inlet side of the engine, a water pump (not shown in the figure) is connected to the outer side of the water inlet part 11, and a cooling water return pipe (not shown in the figure) is connected to the outer side of the water outlet part 12; the water inlet 11 and the water outlet 12 are designed to be located on the same side (right side in the figure) of the water jacket 1, so that when the cooling water pump is pressurized and fed into the water inlet 11, the cooling water flows out of the water jacket 1 along the first flow channel 13 and the second flow channel 14 (the black thick arrow in the figure is the cooling water flowing direction) toward the water outlet 12 and enters the cooling water return pipe to recover cooling heat dissipation; since the lengths and the shapes of the flow paths of the first flow path 13 and the second flow path 14 are different, the difference between the flow rates of the cooling water in the first flow path 13 and the second flow path 14 is caused; more specifically, the flow rate of the cooling water in the first flow channel 13 is greater than the flow rate of the cooling water in the second flow channel 14, so that the cooling effect on the side of the first flow channel 13 is better than the cooling effect on the side of the second flow channel 14, and thus the cooling effect of the whole cylinder head part is uneven; such uneven cooling effect may seriously deteriorate the overall performance of the engine.

Therefore, it is an urgent problem for the vehicle industry to provide a cooling mechanism for cylinders to improve the overall cooling uniformity of the cylinder head of a water-cooled internal combustion engine.

Disclosure of Invention

[ Problem ] to be solved by the invention

The invention mainly aims to provide a cooling mechanism of a cylinder, which can overcome the defect of insufficient homogenization of cooling and heat dissipation of the whole cylinder head in the prior art.

[ Means for solving the problems ]

Therefore, the invention aims to provide a cooling mechanism of a cylinder, the cylinder is provided with a cylinder body and a cylinder head assembled on the cylinder body, and the cylinder head is internally provided with a water jacket for cooling water flow; the cylinder head is provided with a cooling water outlet and a cooling water inlet which are oppositely arranged at opposite sides and communicated with the outside; the water jacket is provided with a water inlet guide passage communicated with the cooling water inlet and a water outlet converging passage connected with the cooling water outlet; the water inlet guide channel is connected with a first annular water channel and a second annular water channel; the other sides of the first annular water channel and the second annular water channel are connected with the water outlet converging channel.

Accordingly, in some embodiments of the present invention, a cooling mechanism for a cylinder is provided, wherein the water outlet manifold has a converging port, and the converging port is biased toward the second annular water channel.

To this end, in some embodiments of the present invention, a cooling mechanism for a cylinder is provided, wherein the water inlet guide of the water jacket has a water inlet guide center line, and the water outlet converging channel has a water outlet converging channel center line; the water jacket forms a middle straight line at the center point of the water inlet guide channel and the center point of the water outlet converging channel; the cylinder head is internally provided with an air inlet valve port at the air inlet passage side and an exhaust valve port at the exhaust passage side, and the water jacket is provided with a straight line for separating the air inlet valve port from the exhaust valve port; the second ring water channel side is concavely provided with a core water channel area towards the center of the cylinder hole.

To this end, in some embodiments of the present invention, a cooling mechanism for a cylinder is provided, wherein the second annular water channel of the water jacket includes a second front annular water channel and a second rear annular water channel; the second front section circular water channel and the second rear section circular water channel are communicated with the core water channel area; the core water channel area is provided with a water inlet end, a water outlet end and a core cavity; the second back section ring water channel comprises a receiving section and a middle section; wherein the cross-sectional area of the waterway channel of the middle section is smaller than that of the waterway channel of the receiving section.

To this end, in some embodiments of the present invention, a cooling mechanism for a cylinder is provided, wherein the second annular water channel of the water jacket includes a second front annular water channel and a second rear annular water channel; the second front section circular water channel and the second rear section circular water channel are communicated with the core water channel area; the core water channel area is provided with a water inlet end, a water outlet end and a core cavity; the sectional area of the water inlet end is larger than that of the water outlet end.

Therefore, in some embodiments of the present invention, a cooling mechanism for a cylinder is provided, wherein an angle formed between an extension line of a center line of the water inlet guide channel toward a cooling water flow direction of the first ring water channel and the middle straight line is smaller than an angle formed between an extension line of a center line of the water outlet converging channel toward a cooling water flow direction of the second ring water channel and the middle straight line.

To this end, some embodiments of the present invention provide a cooling mechanism for a cylinder, the water jacket further having a cooling water inflow hole and a cooling water return hole; the cross-sectional areas of the cooling water inflow hole and the cooling water return hole of the water jacket are divided by the middle straight line, and most of the cross-sectional areas are positioned in the second annular water channel of the water jacket.

To this end, some embodiments of the present invention provide a cooling mechanism for a cylinder, wherein the first annular water channel includes a first front annular water channel connected to the water inlet channel and a first rear annular water channel connected to the water outlet channel; the second annular water channel comprises a second front-section annular water channel communicated with the water inlet guide channel and a second rear-section annular water channel communicated with the water outlet converging channel; wherein the second anterior segment raceway and the second posterior segment raceway are in communication via a channel generally toward the core raceway region; the water jacket is bounded by the straight line, and the length of the first front section annular water channel of the first annular water channel positioned at the exhaust valve port side is longer than that of the second front section annular water channel of the second annular water channel.

To this end, some embodiments of the present invention provide a cooling mechanism for a cylinder, in which a shallow water channel region with a shallower water channel is extended from the first ring water channel toward the cylinder Kong Zhongxin of the cylinder head; a core water channel area is concavely arranged on the second ring water channel side towards the center of the cylinder hole; an igniter is arranged between the core water channel region and the shallow water channel region, and an electrode section of the igniter stretches into the lower part of the core water channel region and the shallow water channel region stretches into the lower part of a plug section of the igniter when the igniter is seen from the cylinder hole axis of the cylinder head.

[ Effect of the invention ]

The effects achieved in some embodiments of the invention are: therefore, the flow velocity difference between the first annular water channel and the second annular water channel can be reduced, and the cooling and heat dissipation uniform effect of the cylinder head can be improved.

The effects achieved in some embodiments of the invention are: therefore, the overall flow velocity of the cooling water of the second annular water channel can be improved, the flow velocity difference between the first annular water channel and the second annular water channel can be reduced, and the cooling and heat dissipation uniform effect of the cylinder head can be improved.

The effects achieved in some embodiments of the invention are: therefore, heat accumulation in the core water channel area near the igniter of the cylinder head can be avoided, and the integral heat dissipation homogenization effect of the cylinder head can be improved.

The effects achieved in some embodiments of the invention are: therefore, the cooling water in the middle section can flow to the receiving section in an accelerated way, and further, heat accumulation in the core water channel area can be avoided, so that the integral heat dissipation homogenization effect of the cylinder head can be improved.

The effects achieved in some embodiments of the invention are: therefore, the exhaust side of the cylinder head can obtain more cooling water contact area, and the cooling and heat dissipation effects of the exhaust side of the cylinder head can be improved.

The effects achieved in some embodiments of the invention are: therefore, the flow rate of the cooling water of the first annular water channel can be controlled, and the flow rate of the cooling water of the second annular water channel can be increased, so that the flow rate difference between the first annular water channel and the second annular water channel can be reduced, and the cooling and heat dissipation uniform effect of the cylinder head can be improved.

The effects achieved in some embodiments of the invention are: therefore, the first annular water channel can quickly and largely cool and dissipate heat of the exhaust valve port side heat source of the cylinder head, and further the cooling and heat dissipation uniformity effect of the cylinder head can be improved.

The effects achieved in some embodiments of the invention are: therefore, the cooling and heat dissipation effects of the vicinity of the installation of the igniter on the cylinder head and the vicinity of the center of the cylinder hole of the cylinder head can be improved.

Drawings

FIG. 1 is a schematic view of a prior art cylinder head water jacket.

Fig. 2 is a perspective view of the cylinder head and cylinder body of the present invention.

Fig. 3 is a bottom view of the water jacket of the cylinder head of the present invention.

FIG. 4 is a schematic view of the intake and exhaust ports and the water jacket of the cylinder head of the present invention.

Fig. 5 is a schematic view of a middle straight line and a flat straight line of the water jacket of the present invention.

Fig. 6 is a top view of the water jacket of the present invention.

FIG. 7 is a partial cross-sectional view of the core waterway area of the water jacket of the present invention.

Fig. 8 is a rear view of the igniter installation of the water jacket of the present invention.

List of reference numerals

1: Water jacket

11: Water inlet 12: water outlet part

13: First flow channel 14: a second flow channel

2: Cylinder with a cylinder head

3: Cylinder head

3A: cylinder head cover

31: Air inlet channel

311: Intake valve port

32: Exhaust passage

321: Exhaust valve port

33: Cooling water outlet 34: cooling water inlet

4: Cylinder body

5: Water pump

51: Cooling water output unit 52: cooling water inlet

6: Water jacket

61: Water inlet guide way

61A: center line of water inlet guide way

62: Water outlet and collecting channel

621: Converging flow port

62A: center line of water outlet converging channel

63: First circular water channel

63A: first front section ring water channel

63B: first rear ring channel 631: shallow water channel region

64: Second ring water channel

64A: second front section ring water channel

64B: second rear section ring water channel

64B1: receiving section 64b2: intermediate section

641: Core waterway area

6411: Water inlet end 6412: water outlet end

6413: Core chamber

65: Cooling water inflow hole

66: Cooling water backflow hole

7: Igniter

71: Electrode segment

72: Plug section

L: middle straight line L1: straight line

Θ, θ1: included angle

L1: cross-sectional length of water inlet end

L2: cross-sectional length of water outlet end

W1: cross-sectional width of water inlet end

W2: cross-sectional width of the water outlet end.

Detailed Description

For easier understanding of the structure and the effects achieved by the present invention, the following description will be given with reference to the accompanying drawings.

First, referring to FIG. 2, the cooling mechanism of the cylinder of the present invention is used for the cylinder 2 of a water-cooled internal combustion engine; the cylinder 2 at least comprises a cylinder head 3 and a cylinder body 4 assembled below the cylinder head 3.

As shown in fig. 2, the cylinder head 3 is assembled above the cylinder body 4; the two sides of the cylinder head 3 are respectively provided with an air inlet channel 31 and an air outlet channel 32, the air inlet channel 31 is outwards connected with an air supply system (not drawn in the figure) for supplying clean air for blasting of the engine 2, and the air supply system at least comprises a throttle valve body, an air filter and the like; the exhaust channel 32 is connected to an exhaust device (not shown) for discharging the exhaust gas after the explosion of the cylinder 2, and the exhaust device at least comprises an exhaust pipe and a muffler pipe; a cylinder head cover 3a is arranged on the upper cover of the cylinder head 3; in practice, the cylinder head cover 3a and the cylinder head 3 may be formed in an integrally formed manner; the outside of the cylinder head 3 is provided with a water pump 5 for outputting cooling water, the water pump 5 can be driven by a driving mechanism arranged in the cylinder head 3, so that external cooling water can be pressurized and input into the cylinder head 3, and the driving mechanism arranged in the cylinder head 3 can be a cam shaft and the like; the water pump 5 has a cooling water output portion 51 and a cooling water input portion 52, and the cooling water input portion 52 is connected to a cooling water radiator (not shown) by a pipe, whereby the water cooled in the cooling water radiator can be pumped out through the cooling water input portion 52 after the water pump 5 is operated, and then the cooling water is input into the cylinder head 3 through the cooling water output portion 51.

As shown in fig. 2 and 3, the cylinder head 3 is provided with a cooling water outlet 33 on the intake duct 31 side; the cylinder head 31 is provided with a cooling water inlet 34 on the exhaust passage 32 side; the cooling water inlet 34 is connected with the cooling water output part 51 of the water pump 5, and the outer side of the cooling water outlet 33 is connected with a cooling water radiator through a connecting pipe fitting; the cooling water inlet 34 and the cooling water outlet 33 are disposed in opposite sides, for example, as shown in fig. 2 and 3, the cooling water inlet 34 is disposed at the lower right corner of the drawing, and the cooling water outlet 33 is disposed at the upper left corner of the drawing; a water jacket 6 for cooling water flow is arranged in the cylinder head 3; the water jacket 6 has a water inlet channel 61 connected to the cooling water inlet 34 and a water outlet channel 62 connected to the cooling water outlet 33, and the water inlet channel 61 and the water outlet channel 62 are disposed in opposite directions; the water jacket 6 has a first annular water channel 63 and a second annular water channel 64 connected to the water inlet guide channel 61 and the water outlet sink channel 62; after the cooling water is input into the cooling water inlet 34 by the cooling water input part 52, the cooling water flows through the water inlet guide channel 61 and is split by the first annular water channel 63 and the second annular water channel 64, and flows out of the cylinder head 3 from the cooling water outlet 33 after being converged by the water outlet converging channel 62, and the black thick line with an arrow in fig. 3 is the flowing direction of the cooling water; the water jacket 6 is provided with a cooling water inflow hole 65 at the junction of the water inflow guide channel 61 and the first and second annular water channels 63 and 64 for cooling the cylinder body 4, and a cooling water backflow hole 66 at the junction of the water outflow guide channel 62 and the first and second annular water channels 63 and 64 for cooling water backflow of the cylinder body 4, so that the cooling water conveyed by the water pump 5 can cool the cylinder head 3 and simultaneously cool the cylinder body 4, thereby ensuring the operation efficiency and service life of the cylinder 2; furthermore, by arranging the cooling water inflow hole 65 and the cooling water return hole 66 in the above manner, the cooling water flowing through the cylinder head 3 and the cylinder body 4 can be effectively controlled without providing an isolation mechanism in addition to the cylinder head 3 or the cylinder body 4.

As shown in fig. 3, 4, 5 and 8, the water jacket 6 is provided with a shallow water channel area 631 with a shallower water channel extending from the first annular water channel 63 toward the cylinder Kong Zhongxin of the cylinder head 3; the second annular water channel 64 is provided with a core water channel area 641 toward the center of the cylinder hole in a concave manner; an igniter 7 is installed between the core water channel area 641 and the shallow water channel area 631, and the electrode section 71 of the igniter 7 extends into the lower part of the core water channel area 641 and the shallow water channel area 631 extends into the lower part of the plug section 72 of the igniter 7 as seen from the cylinder hole axial direction of the cylinder head 3; thereby improving the cooling effect of the igniter 7 and the igniter mounting seat (not shown) for mounting the igniter 7 and the central part of the cylinder head 3.

As shown in fig. 2,3, 4,5, the water intake guide 61 of the water jacket 6 has a water intake guide center line 61a, and the water outlet manifold 62 has a water outlet manifold center line 62a; the water jacket 6 forms a middle straight line L between the center point of the water inlet guide channel 61 and the center point of the water outlet converging channel 62; the cylinder head 3 has an intake port 311 on the intake port 31 side and an exhaust port 321 on the exhaust port 32 side, and the water jacket 6 has a straight line L1 separating the intake port 311 from the exhaust port 321; wherein, the water outlet converging channel 62 is provided with a converging port 621 adjacent to the first annular water channel 63 and the second annular water channel 64, the converging port 621 is deviated to the second annular water channel 64, so that the cooling water entering the water jacket 6 as a whole can flow into the second annular water channel 64 more than the cooling water entering the first annular water channel 63; thereby, the flow velocity difference of the cooling water flowing into the water outlet converging channel 62 from the first annular water channel 63 and the second annular water channel 64 can be reduced, and the uneven cooling problem of the cylinder head 3 can be avoided.

As shown in fig. 3,4 and 5, the first water circulating channel 63 of the water jacket 6 includes a first front-stage water circulating channel 63a connected to the water inlet channel 61 and a first rear-stage water circulating channel 63b connected to the water outlet channel 62; the second circular water channel 64 comprises a second front circular water channel 64a communicated with the water inlet guide channel 61 and a second rear circular water channel 64b communicated with the water outlet converging channel 62; wherein the second front stage annular water passage 64a and the second rear stage annular water passage 64b are communicated via the core water passage area 641 recessed substantially toward the cylinder hole center of the cylinder head 3.

As shown in fig. 3, 4, 5, 8, the core raceway area 641 has a water inlet end 6411 communicating with the second front-stage raceway 64a, a water outlet end 6412 communicating with the second rear-stage raceway 64b, and a core chamber 6413 communicating the water inlet end 6411 with the water outlet end 6412; the second rear-stage raceway 64b includes a receiving section 64b1 adjacent the outlet end 6412 and an intermediate section 64b2 adjacent the outlet sink 62; the cross-sectional area of the waterway of the middle section 64b2 (as shown in the enlarged view a-a of fig. 4) is smaller than the cross-sectional area of the waterway of the receiving section 64b1 (as shown in the enlarged view b-b of fig. 4), so that the cooling water flowing through the core waterway area 641 (i.e. flowing through the core chamber 6413) can be accelerated to flow out toward the water outlet sink 62, thereby avoiding thermal damage caused by heat accumulation in the core waterway area 641, and achieving better heat dissipation effect around the igniter 7.

As shown in fig. 3,4, 6 and 7, the cross-sectional area of the water inlet 6411 of the core water channel region 641 is larger than the cross-sectional area of the water outlet 6412, and the cross-sectional portion of the core water channel region 641 in fig. 7 is the cross-sectional c-view of fig. 6, wherein W1 in fig. 7 represents the cross-sectional width of the water inlet 6411 and W2 represents the cross-sectional width of the water outlet 6412; l1 the cross-sectional length of the water inlet end 6411, L2 the cross-sectional length of the water outlet end 6412; therefore, when part of cooling water enters the second annular water channel 64 from the water inlet guide channel 61, the water inlet end 6411 is cooled and radiated, and the sectional area of the water inlet end 6411 is larger than that of the water outlet end 6412, and the water inlet end 6411 is positioned on the exhaust passage 32, so that the exhaust passage 32 at the hottest position of the cylinder head 3 can obtain better cooling and radiating effects, thereby further avoiding thermal damage caused by heat accumulation in the core water channel region 641, and simultaneously obtaining better radiating effects around the igniter 7.

As shown in fig. 2,3, 4 and 5, an included angle θ formed by an extension line of the water inlet guide line center line 61a of the water inlet guide line 61 toward the cooling water flow direction of the first circular water channel 63 and the middle straight line L is smaller than 45 degrees; the central line 62a of the water outlet and collecting channel 62 forms an included angle θ1 with the middle straight line L, which is greater than 45 degrees, that is, the included angle θ1 is greater than the included angle θ, so that the flow rate of the cooling water flowing into the end of the water outlet and collecting channel 62 of the first water channel 63 can be effectively inhibited, the flow rate of the cooling water flowing into the end of the water outlet and collecting channel 62 of the second water channel 64 can be increased, and the flow rates of the cooling water flowing into the two sides of the first water channel 63 and the second water channel 64 can be reduced by a speed difference; meanwhile, the included angle θ1 is larger, so that the cooling water flowing through the second annular water channel 64 can more smoothly flow into the water outlet and collecting channel 62, and further, most of the cooling water can be guided into the second annular water channel 64 after the cooling water flows into the water inlet guide channel 61, so that the cooling heat dissipation of the cylinder head 3 can be homogenized.

As shown in fig. 3,4 and 5, the cross-sectional areas of the cooling water inflow hole 65 and the cooling water return hole 66 of the water jacket 6 are defined by the middle straight line L, and most of the cross-sectional areas are located in the second annular water channel 64 of the water jacket 6; more specifically, the cooling water inflow hole 65 is defined by the middle straight line L, and the total area of the inner cross section of the first annular water channel 63 is smaller than the total area of the inner cross section of the second annular water channel 64; the cooling water return hole 66 is defined by the straight line L, and the total area of the inner cross section of the first annular water channel 63 is smaller than the total area of the inner cross section of the second annular water channel 64; thereby, the amount of cooling water flowing into the cylinder body 42 can be effectively controlled, and the flow rate of cooling water flowing into the outlet manifold 62 from the second ring water passage 64 can be further improved by the outlet of the cooling water return hole 66 being located mostly in the second ring water passage 64.

As shown in fig. 4 and 5, the water jacket 6 is bounded by the straight line L1 separating the intake port 311 from the exhaust port 321, and the length of the first front-stage annular water channel 63a of the first annular water channel 63 located on the exhaust port 321 side is longer than the length of the second front-stage annular water channel 64a of the second annular water channel 64, so that the cylinder head 3 can obtain a better cooling and heat dissipation effect on the exhaust port 321 side.

The invention is mainly characterized in that the cylinder 2 is provided with a cylinder body 4 and a cylinder head 3 assembled on the cylinder body 4, and the cylinder head 3 is internally provided with a water jacket 6 for cooling water flow; the cylinder head 3 has a cooling water outlet 33 and a cooling water inlet 34 which are disposed opposite to each other and communicate with the outside; the water jacket 6 has a water inlet guide passage 61 communicating with the cooling water inlet 33, and a water outlet sink passage 62 connected to the cooling water outlet 33; the water inlet guide channel 61 is connected with a first circular water channel 63 and a second circular water channel 64; the other sides of the first circular water channel 63 and the second circular water channel 64 are connected with the water outlet manifold 62; this reduces the difference in flow rates between the first annular water passage 63 and the second annular water passage 64, thereby improving the cooling and heat dissipation uniformity of the cylinder head 3.

The cooling mechanism of the cylinder can achieve the aim of requirements by the structure, and the cooling mechanism of the cylinder meets the novelty, creativity and practicability of the invention patent.

Claims (9)

1. A cooling mechanism of a cylinder, which is characterized in that the cylinder is provided with a cylinder body and a cylinder head assembled on the cylinder body, and the cylinder head is internally provided with a water jacket for cooling water flow; the cylinder head is provided with a cooling water outlet and a cooling water inlet which are oppositely arranged at opposite sides and communicated with the outside; the water jacket is provided with a water inlet guide passage communicated with the cooling water inlet and a water outlet converging passage connected with the cooling water outlet; the water inlet guide channel is connected with a first circular water channel and a second circular water channel; the other sides of the first annular water channel and the second annular water channel are connected with the water outlet converging channel.

2. The cooling mechanism of claim 1, wherein the outlet manifold has a converging port that is biased toward the second ring water passage.

3. The cooling mechanism of the cylinder according to claim 1, wherein the water intake guide of the water jacket has a water intake guide center line, and the water outlet manifold has a water outlet manifold center line; the water jacket forms a middle straight line at the center point of the water inlet guide channel and the center point of the water outlet converging channel; the cylinder head is internally provided with an air inlet valve port at the air inlet passage side and an exhaust valve port at the exhaust passage side, and the water jacket is provided with a straight line for separating the air inlet valve port from the exhaust valve port; and a core water channel area is concavely arranged on the second annular water channel side towards the center of the cylinder hole.

4. A cooling mechanism for a cylinder according to claim 1 or 3, wherein the second annular water passage of the water jacket includes a second front-stage annular water passage and a second rear-stage annular water passage; the second front section annular water channel and the second rear section annular water channel are communicated with the core water channel area; the core water channel area is provided with a water inlet end, a water outlet end and a core cavity; the second rear section circular water channel comprises a receiving section and an intermediate section; wherein the cross-sectional area of the waterway channel of the middle section is smaller than the cross-sectional area of the waterway channel of the receiving section.

5. A cooling mechanism for a cylinder according to claim 1 or 3, wherein the second annular water passage of the water jacket includes a second front-stage annular water passage and a second rear-stage annular water passage; the second front section annular water channel and the second rear section annular water channel are communicated with the core water channel area; the core water channel area is provided with a water inlet end, a water outlet end and a core cavity; the sectional area of the water inlet end is larger than that of the water outlet end.

6. A cooling mechanism for a cylinder as claimed in claim 3, wherein an angle formed by an extension line of a center line of the water inlet guide channel toward a cooling water flow direction of the first circular water channel and the middle straight line is smaller than an angle formed by an extension line of a center line of the water outlet sink channel toward a cooling water flow direction of the second circular water channel and the middle straight line.

7. The cooling mechanism of the cylinder according to claim 6, wherein the water jacket further has a cooling water inflow hole and a cooling water return hole; the cooling water inflow hole and the cooling water return hole of the water jacket are divided into cross sections, and most of the cross sections are located in the second annular water channel of the water jacket by the middle straight line.

8. The cooling mechanism of claim 6, wherein the first annular water passage includes a first front annular water passage communicating with the water intake passage and a first rear annular water passage communicating with the water outlet manifold passage; the second annular water channel comprises a second front-section annular water channel communicated with the water inlet guide channel and a second rear-section annular water channel communicated with the water outlet converging channel; wherein the second anterior segment raceway communicates with the second posterior segment raceway via a channel generally toward the core raceway region; the water jacket is defined by the straight line, and the length of a first front section of the first annular water channel positioned at the exhaust valve port side is longer than that of a second front section of the second annular water channel.

9. The cooling mechanism of claim 1, wherein the water jacket extends from the first annular water channel toward the cylinder Kong Zhongxin of the cylinder head to form a shallow water channel region with a shallower water channel; a core water channel area is concavely arranged on the second annular water channel side towards the center of the cylinder hole; an igniter is arranged between the core water channel region and the shallow water channel region, and is seen from the cylinder hole of the cylinder head in the axial direction, an electrode section of the igniter stretches into the lower part of the core water channel region, and the shallow water channel region stretches into the lower part of a plug section of the igniter.