阅读说明：本技术 一种对置发动机的缸体冷却水道结构 (Cylinder body cooling water channel structure of opposed engine ) 是由 温国生 刘地长 于 2018-08-10 设计创作，主要内容包括：本发明涉及一种对置发动机的缸体冷却水道结构,包括缸体、气缸套；在缸体中部偏上的左右两侧分别设有一个进气孔、中部的左右两侧分别设有一个喷油器安装过孔、中部偏下的左右两侧分别设有一个排气孔,在缸体后侧的下部设有两个进水孔、上部设有两个回水孔；在缸体下部设有第一外冷却水道和与之相通的第一内冷却水道,第一外冷却水道包住排气孔并与进水孔相通；在气缸套的中部设有第二内冷却水道、上部设有与第二内冷却水道相通的第二外冷却水道,第二外冷却水道与回水孔相通；第一外冷却水道和第一内冷却水道均与第二内冷却水道相通；还包括设在所述缸体中部上的喷油器。本发明能够有效的冷却缸套的燃烧室区域及缸体上的排气孔区域。(The invention relates to a cylinder body cooling water channel structure of an opposed engine, which comprises a cylinder body and a cylinder sleeve; the left side and the right side of the upper middle part of the cylinder body are respectively provided with an air inlet hole, the left side and the right side of the middle part are respectively provided with an oil injector mounting through hole, the left side and the right side of the lower middle part are respectively provided with an exhaust hole, the lower part of the rear side of the cylinder body is provided with two water inlet holes, and the upper part of the rear side of the cylinder body is provided with two water; a first outer cooling water channel and a first inner cooling water channel communicated with the first outer cooling water channel are arranged at the lower part of the cylinder body, and the first outer cooling water channel wraps the exhaust hole and is communicated with the water inlet hole; a second inner cooling water channel is arranged in the middle of the cylinder sleeve, a second outer cooling water channel communicated with the second inner cooling water channel is arranged at the upper part of the cylinder sleeve, and the second outer cooling water channel is communicated with the water return hole; the first outer cooling water channel and the first inner cooling water channel are communicated with the second inner cooling water channel; the oil sprayer is arranged on the middle part of the cylinder body. The invention can effectively cool the combustion chamber area of the cylinder sleeve and the exhaust hole area on the cylinder body.)

1. A cylinder cooling water channel structure of an opposed engine comprises a cylinder (1) and a cylinder sleeve (2) which is matched in the cylinder and penetrates through the cylinder; the left side and the right side of the upper middle part of the cylinder body (1) are respectively provided with an air inlet hole (11), the left side and the right side of the middle part are respectively provided with an oil injector mounting through hole (12), the left side and the right side of the lower middle part are respectively provided with an exhaust hole (13), the lower part of the rear side of the cylinder body (1) is provided with two water inlet holes (14), and the upper part of the rear side of the cylinder body is provided with two water return holes (; the method is characterized in that:

a first outer cooling water channel (16) and a first inner cooling water channel (30) communicated with the first outer cooling water channel are arranged at the lower part of the cylinder body (1), and the first outer cooling water channel (16) wraps the exhaust hole (13) and is communicated with the water inlet hole (14); a second inner cooling water channel (40) is arranged in the middle of the cylinder sleeve (2), a second outer cooling water channel (19) communicated with the second inner cooling water channel is arranged at the upper part of the cylinder sleeve, and the second outer cooling water channel (19) is communicated with the water return hole (15); the first outer cooling water channel (16) and the first inner cooling water channel (30) are communicated with the second inner cooling water channel (40); the fuel injector is characterized by further comprising a fuel injector (5) arranged in the middle of the cylinder body (1).

2. The cylinder cooling water passage structure of the opposed engine as set forth in claim 1, wherein: the left side and the right side of the lower part of the cylinder body (1) are respectively provided with a first external cooling water channel (16), and the two first external cooling water channels respectively wrap an exhaust hole (13); a lower water through hole (17) is formed in the lower portion of the inner side wall of the first outer cooling water channel (16), and an upper water through hole (18) is formed in the upper portion of the inner side wall of the first outer cooling water channel; the two first outer cooling water channels (16) are respectively communicated with a water inlet hole (14); the left side and the right side of the upper portion of the cylinder body (1) are respectively provided with a second external cooling water channel (19), the second external cooling water channels are located between the air inlet hole (11) and the oil sprayer installation through hole (12), the inner side wall of each second external cooling water channel (19) is provided with a water passing hole (10), and the two second external cooling water channels (19) are respectively communicated with a water return hole (15).

3. The cylinder cooling water passage structure of an opposed engine according to claim 1 or 2, wherein: the upper end of the cylinder sleeve (2) is provided with a limiting flange (20), the upper part of the middle part of the cylinder sleeve is provided with a plurality of air inlet through holes (21) which are distributed equidistantly along the radial direction, the left side and the right side of the middle part of the cylinder sleeve are respectively provided with a fuel injector mounting hole (22), the lower part of the middle part of the cylinder sleeve is provided with a plurality of exhaust through holes (23) which are distributed equidistantly along the radial direction and a plurality of axial water passing holes (24), and the exhaust through holes (23) and the axial water passing.

4. The cylinder cooling water passage structure of an opposed engine according to claim 1 or 2, wherein: the cylinder sleeve (2) is matched with the inner cavity of the cylinder body (1), a limiting flange (20) at the upper end of the cylinder sleeve is abutted against the upper end of the cylinder body, and the lower end of the cylinder sleeve extends out of the cylinder body; the two air inlet through holes (21) on the same diameter of the cylinder sleeve correspond to the two air inlet holes (11) on the cylinder body (1) one by one respectively, the two oil injector mounting holes (22) on the cylinder sleeve correspond to the two oil injector mounting through holes (12) on the cylinder body (1) one by one respectively, and the two exhaust through holes (23) on the same diameter of the cylinder sleeve correspond to the two exhaust holes (13) on the cylinder body (1) one by one; a first inner cooling water channel (30) is formed between the outer wall of the lower part of the cylinder sleeve (2) and the inner side wall of the first outer cooling water channel (16), and the first inner cooling water channel (30) is communicated with the first outer cooling water channel (16) through a lower water through hole (17); a second inner cooling water channel (40) is formed between the middle outer wall of the cylinder sleeve (2) and the middle inner wall of the cylinder body (1), and the lower part of the second inner cooling water channel (40) is communicated with the first outer cooling water channel (16) through the upper water through hole (18); the first inner cooling water channel (30) is communicated with a second inner cooling water channel (40) through an axial water through hole (24), and the upper portion of the second inner cooling water channel (40) is communicated with the second outer cooling water channel (19) through the water through hole (10).

5. The cylinder cooling water passage structure of an opposed engine according to claim 1 or 2, wherein: the two oil injectors (5) are respectively arranged on the left side and the right side of the middle part of the cylinder body (1); the two fuel injectors (5) are respectively matched, positioned and connected with the fuel injector mounting through hole (12) and the fuel injector mounting hole (22) through a sheath (9).

6. The cylinder cooling water passage structure of an opposed engine according to claim 1 or 2, wherein: two first rectangular ring grooves (111) are formed in the contact part of the upper inner wall of the middle part of the cylinder body (1) and the outer wall of the cylinder sleeve (2), and the air inlet hole (11) is located between the two first rectangular ring grooves (111); and first sealing rings (3) are respectively matched in the two first rectangular ring grooves (111).

7. The cylinder cooling water passage structure of an opposed engine according to claim 1 or 2, wherein: the inner walls of the two oil sprayer mounting through holes (12) in the cylinder body (1) are respectively provided with a second rectangular ring groove (121), and the second rectangular ring grooves (121) are respectively matched with second sealing rings (6).

8. The cylinder cooling water passage structure of an opposed engine according to claim 1 or 2, wherein: the exhaust hole (13) is positioned between the two third rectangular ring grooves (131) on the lower inner wall of the middle part of the cylinder body (1) and the two third rectangular ring grooves (131); and third sealing rings (4) are respectively matched in the two third rectangular ring grooves (131).

9. The cylinder cooling water passage structure of an opposed engine according to claim 1 or 2, wherein: a fourth rectangular ring groove (141) is formed in the position, close to the contact part of the inner wall of the lower end of the cylinder body (1) and the outer wall of the cylinder sleeve (2), and a fourth sealing ring (11) is arranged in the fourth rectangular ring groove (141).

10. The cylinder cooling water passage structure of an opposed engine according to claim 5, wherein: the protective sleeve (9) is step-shaped, and a first copper gasket (7) is arranged at the contact part of the fuel injector (5) and the step on the inner wall of the protective sleeve (9) and used for sealing gas; and a second copper gasket (8) is arranged at the contact part of the step of the outer wall of the sheath (9) and the edge of the oil sprayer mounting hole (22).

Technical Field

The invention relates to an opposed engine, in particular to a cylinder cooling water channel structure of the opposed engine.

Background

The engine comprises opposed engines, two opposed pistons are arranged in each cylinder sleeve, the two pistons move oppositely and relatively, an oil injector is arranged in the middle of the cylinder sleeve, the oil injector arranged on the cylinder sleeve injects oil into a combustion chamber formed by the opposed pistons and ignites and burns, and high-temperature waste gas is discharged through an exhaust hole in a cylinder body. The temperature around the combustion chamber and the exhaust hole of the cylinder body of the cylinder sleeve is very high, and an efficient cylinder body cooling water channel must be designed to ensure the cooling of the combustion chamber and the exhaust hole of the cylinder body.

CN 204082333U discloses a mechanical supercharging type internal air cooling water parallel-opposed engine, which comprises a cylinder block assembly, a piston connecting rod assembly, a crankshaft assembly, a valve mechanism, an ignition system, a combustion gas inlet system, a combustion waste gas exhaust system, a cooling system, a lubricating system and a crankcase, wherein a turbofan a is arranged in the combustion gas inlet system, a turbofan b is arranged in the combustion waste gas exhaust system, a turbofan c is arranged in the cooling system, radiating fins are arranged on the outer wall of the cylinder block, the outer wall of the cylinder cover and the hollow part of the cylinder block, and a cooling cavity shell is sleeved on the radiating fins. The closed cooling cavity is arranged, and cooling air is guided to be in full contact with the radiating fins through the cooling air pipeline, so that heat is taken away; simultaneously, all set up mechanical supercharging device in combustion gas intake pipe, combustion gas blast pipe and cooling gas exhaust pipe, realize advancing the full pressure boost of exhaust to reach the effect that the combustion gas burning is abundant, the burning exhaust gas discharges completely, the cooling gas rapid cycle. The patent adopts the air cooling mode to cool the cylinder block and the cylinder cover. This is, of course, a useful attempt in the art.

Disclosure of Invention

The invention aims to provide a cylinder cooling water channel structure of an opposed engine, which can effectively cool a combustion chamber area of a cylinder sleeve and an exhaust hole area on a cylinder body and ensure the reliable operation of the engine.

The invention relates to a cylinder body cooling water channel structure of an opposed engine, which comprises a cylinder body and a cylinder sleeve, wherein the cylinder sleeve is matched in the cylinder body and penetrates through the cylinder body; the left side and the right side of the upper middle part of the cylinder body are respectively provided with an air inlet hole, the left side and the right side of the middle part of the cylinder body are respectively provided with an oil injector mounting through hole, the left side and the right side of the lower middle part of the cylinder body are respectively provided with an exhaust hole, the lower part of the rear side of the cylinder body is provided with two water inlet holes, and the upper part of the rear side of the cylinder; the method is characterized in that: a first outer cooling water channel and a first inner cooling water channel communicated with the first outer cooling water channel are arranged at the lower part of the cylinder body, and the first outer cooling water channel wraps the exhaust hole and is communicated with the water inlet hole; a second inner cooling water channel is arranged in the middle of the cylinder sleeve, a second outer cooling water channel communicated with the second inner cooling water channel is arranged at the upper part of the cylinder sleeve, and the second outer cooling water channel is communicated with the water return hole; the first outer cooling water channel and the first inner cooling water channel are communicated with the second inner cooling water channel; the oil sprayer is arranged on the middle part of the cylinder body.

Furthermore, the left side and the right side of the lower part of the cylinder body are respectively provided with a first external cooling water channel, and the two first external cooling water channels respectively wrap an exhaust hole; a lower water through hole is formed in the lower part of the inner side wall of the first outer cooling water channel, and an upper water through hole is formed in the upper part of the inner side wall of the first outer cooling water channel; the two first outer cooling water channels are respectively communicated with a water inlet hole; and the left side and the right side of the upper part of the cylinder body are respectively provided with a second external cooling water channel, the second external cooling water channel is positioned between the air inlet and the oil injector mounting through hole, the inner side wall of the second external cooling water channel is provided with a water through hole, and the two second external cooling water channels are respectively communicated with a water return hole.

Furthermore, the upper end of the cylinder sleeve is provided with a limiting flange, the upper part of the middle part of the cylinder sleeve is provided with a plurality of air inlet through holes which are distributed equidistantly and radially, the left side and the right side of the middle part of the cylinder sleeve are respectively provided with a fuel injector mounting hole, the lower part of the middle part of the cylinder sleeve is provided with a plurality of exhaust through holes which are distributed equidistantly and radially and a plurality of axial water through holes, and the exhaust through holes and the axial water through holes are arranged alternately.

Furthermore, the cylinder sleeve is matched with the inner cavity of the cylinder body, a limiting flange at the upper end of the cylinder sleeve is abutted against the upper end of the cylinder body, and the lower end of the cylinder sleeve extends out of the cylinder body; the two air inlet through holes on the same diameter of the cylinder sleeve correspond to the two air inlet holes on the cylinder body one by one respectively, the two oil injector mounting holes on the cylinder sleeve correspond to the two oil injector mounting through holes on the cylinder body one by one respectively, and the two exhaust through holes on the same diameter of the cylinder sleeve correspond to the two exhaust holes on the cylinder body one by one; a first inner cooling water channel is formed between the outer wall of the lower part of the cylinder sleeve and the inner side wall of the first outer cooling water channel and is communicated with the first outer cooling water channel through a lower water through hole; a second inner cooling water channel is formed between the outer wall of the middle part of the cylinder sleeve and the inner wall of the middle part of the cylinder body, and the lower part of the second inner cooling water channel is communicated with the first outer cooling water channel through the upper water through hole; the first inner cooling water channel is communicated with the second inner cooling water channel through an axial water through hole, and the upper portion of the second inner cooling water channel is communicated with the second outer cooling water channel through the water through hole.

Furthermore, the two oil injectors are respectively arranged on the left side and the right side of the middle part of the cylinder body; the two fuel injectors are respectively matched, positioned and connected with the fuel injector mounting through hole and the fuel injector mounting hole through a sheath.

Furthermore, two first rectangular ring grooves are formed in the contact part of the upper inner wall of the middle part of the cylinder body and the outer wall of the cylinder sleeve, and the air inlet hole is located between the two first rectangular ring grooves; and first sealing rings are respectively matched in the two first rectangular ring grooves.

And further, the inner walls of the two oil sprayer mounting through holes on the cylinder body are respectively provided with a second rectangular ring groove, and second sealing rings are respectively matched in the second rectangular ring grooves.

Furthermore, the exhaust hole is positioned between the two third rectangular ring grooves; and third sealing rings are respectively matched in the two third rectangular ring grooves.

Furthermore, a fourth rectangular ring groove is formed in the position, close to the contact part of the inner wall of the lower end of the cylinder body and the outer wall of the cylinder sleeve, and a fourth sealing ring is arranged in the fourth rectangular ring groove.

Further, the sheath is step-shaped, and a first copper gasket is arranged at the contact part of the fuel injector and the step on the inner wall of the sheath; and a second copper gasket is arranged at the contact part of the step of the outer wall of the sheath and the edge of the oil sprayer mounting hole.

The beneficial technical effects of the invention are as follows: because the first external cooling water channel is arranged to wrap the exhaust hole, the temperature of the cooling water entering the first external cooling water channel from the water inlet hole is lower, and the cooling effect is very obvious when the cooling water is used for cooling the exhaust hole area with higher temperature; because the two paths of cooling water of the first outer cooling water channel enter the second inner cooling water channel, the combustion chamber area of the cylinder sleeve is fully cooled, so that the temperatures of the cylinder sleeve and the exhaust hole are greatly reduced, and the reliable operation of the engine is ensured.

Drawings

FIG. 1 is a schematic external view of the present invention;

FIG. 2 is a top view of FIG. 1;

FIG. 3 is a schematic view of the structure of the cylinder;

figure 4 is a schematic diagram of a cylinder liner construction;

FIG. 5 is a cross-sectional view A-A of FIG. 2;

FIG. 6 is a cross-sectional view B-B of FIG. 5;

FIG. 7 is a cross-sectional view C-C of FIG. 5;

FIG. 8 is a cross-sectional view taken along line D-D of FIG. 5;

FIG. 9 is a cross-sectional view E-E of FIG. 5;

fig. 10 is a sectional view F-F of fig. 5.

In the figure: 1-cylinder body, 10-water passing hole, 11-air inlet hole, 12-oil injector installation through hole, 13-exhaust hole, 14-water inlet hole, 15-water return hole, 16-first external cooling water channel, 17-lower water passing hole, 18-upper water passing hole and 19-second external cooling water channel; 111-a first rectangular ring groove, 121-a second rectangular ring groove, 131-a third rectangular ring groove, 141-a fourth rectangular ring groove;

2-cylinder jacket, 20-limit flange, 21-air inlet through hole, 22-oil injector mounting hole, 23-exhaust through hole (23) and 24-axial water through hole;

3-a first sealing ring, 4-a second sealing ring, 5-an oil injector, 6-a third sealing ring, 7-a first copper gasket, 8-a second copper gasket, 9-a sheath and 11-a fourth sealing ring;

30-a first inner cooling flume, and 40-a second inner cooling flume.

Detailed Description

To further illustrate the structure and function of the present invention, the following detailed description of the invention is given with reference to the accompanying drawings and preferred embodiments, but it should be understood that the scope of the invention is not limited to the specific embodiments. For convenience of description, the orientations of fig. 1, i.e., front, rear, upper, lower, left and right, are defined, but not intended to limit the use orientation of the present invention.

Referring to fig. 1 to 10, the cylinder cooling water channel structure of an opposed engine includes a cylinder 1, a cylinder liner 2 fitted in the cylinder and penetrating the cylinder; the left side and the right side of the upper middle part of the cylinder body 1 are respectively provided with an air inlet 11, the left side and the right side of the middle part are respectively provided with an oil injector mounting through hole 12, the left side and the right side of the lower middle part are respectively provided with an exhaust hole 13, the lower part of the rear side of the cylinder body 1 is provided with two water inlet holes 14, and the upper part of the rear side of the cylinder body 1 is provided with two water return holes 15; the prominent substantive features are as follows:

a first outer cooling water channel 16 and a first inner cooling water channel 30 communicated with the first outer cooling water channel 16 are arranged at the lower part of the cylinder body 1, and the first outer cooling water channel 16 wraps the exhaust hole 13 and is communicated with the water inlet hole 14; a second inner cooling water channel 40 is arranged in the middle of the cylinder sleeve 2, a second outer cooling water channel 19 communicated with the second inner cooling water channel is arranged at the upper part of the cylinder sleeve, and the second outer cooling water channel 19 is communicated with the water return hole 15; the first outer cooling water channel 16 and the first inner cooling water channel 30 are both in communication with a second inner cooling water channel 40; the fuel injector is characterized by further comprising a fuel injector 5 arranged in the middle of the cylinder body 1. The cooling temperature of the first external cooling water channel entering from the water inlet hole is low, and the first external cooling water channel is used for cooling the exhaust hole area with high temperature, so that the cooling effect is very obvious.

The left side and the right side of the lower part of the cylinder body 1 are respectively provided with a first external cooling water channel 16, and the two first external cooling water channels respectively wrap an exhaust hole 13; a lower water through hole 17 is formed in the lower portion of the inner side wall of the first outer cooling water channel 16, and an upper water through hole 18 is formed in the upper portion of the inner side wall of the first outer cooling water channel; the two first outer cooling water channels 16 are respectively communicated with a water inlet hole 14; and second external cooling water channels 19 are respectively arranged on the left side and the right side of the upper part of the cylinder body 1, the second external cooling water channels are positioned between the air inlet 11 and the oil injector installation through hole 12, water through holes 10 are formed in the inner side wall of each second external cooling water channel 19, and the two second external cooling water channels 19 are respectively communicated with a water return hole 15.

The upper end of the cylinder sleeve 2 is provided with a limiting flange 20, the upper part of the middle part of the cylinder sleeve is provided with a plurality of air inlet through holes 21 which are distributed equidistantly and radially, the left side and the right side of the middle part of the cylinder sleeve are respectively provided with a fuel injector mounting hole 22, the lower part of the middle part of the cylinder sleeve is provided with a plurality of exhaust through holes 23 which are distributed equidistantly and radially and a plurality of axial water through holes 24, and the exhaust through holes 23 and the axial water through holes 24 are arranged alternately;

the cylinder sleeve 2 is matched with the inner cavity of the cylinder body 1, a limiting flange 20 at the upper end of the cylinder sleeve is abutted against the upper end of the cylinder body, and the lower end of the cylinder sleeve extends out of the cylinder body; two air inlet through holes 21 on the same diameter of the cylinder sleeve correspond to two air inlet holes 11 on the cylinder body 1 one by one respectively, two fuel injector mounting holes 22 on the cylinder sleeve correspond to two fuel injector mounting through holes 12 on the cylinder body 1 one by one respectively, and two exhaust through holes 23 on the same diameter of the cylinder sleeve correspond to two exhaust holes 13 on the cylinder body 1 one by one;

a first inner cooling water passage 30 is formed between the lower outer wall of the cylinder liner 2 and the inner side wall of the first outer cooling water passage 16, and the first inner cooling water passage 30 is communicated with the first outer cooling water passage 16 through a lower water through hole 17; a second inner cooling water channel 40 is formed between the middle outer wall of the cylinder liner 2 and the middle inner wall of the cylinder block 1, and the lower part of the second inner cooling water channel 40 is communicated with the first outer cooling water channel 16 through the upper water through hole 18; the first inner cooling water channel 30 is communicated with a second inner cooling water channel 40 through an axial water through hole 24, and the upper part of the second inner cooling water channel 40 is communicated with the second outer cooling water channel 19 through the water through hole 10.

The two oil injectors 5 are respectively arranged on the left side and the right side of the middle part of the cylinder body 1; the two fuel injectors 5 are respectively matched, positioned and connected with the fuel injector mounting through hole 12 and the fuel injector mounting hole 22 through a sheath 9.

Two first rectangular ring grooves 111 are formed in the contact part of the upper inner wall of the middle part of the cylinder body 1 and the outer wall of the cylinder sleeve 2, and the air inlet 11 is located between the two first rectangular ring grooves 111; the two first rectangular ring grooves 111 are respectively matched with a first sealing ring 3 for sealing water and gas.

The inner walls of the two oil sprayer mounting through holes 12 in the cylinder body 1 are respectively provided with a second rectangular ring groove 121, and second sealing rings (6) are respectively matched in the second rectangular ring grooves 121. And the cooling water is used for sealing the second inner cooling water channel and preventing the cooling water from flowing out of the cylinder body.

The lower inner wall of the middle part of the cylinder body 1 and two third rectangular ring grooves 131, and the exhaust hole 13 is positioned between the two third rectangular ring grooves 131; and third sealing rings 4 are respectively matched in the two third rectangular ring grooves 131 and used for sealing cooling water of the first inner cooling water channel and the second inner cooling water channel and sealing high-temperature gas of the exhaust holes.

A fourth rectangular ring groove 141 is formed in a position, close to the contact part of the inner wall of the lower end of the cylinder body 1 and the outer wall of the cylinder sleeve 2, and a fourth sealing ring 11 is arranged in the fourth rectangular ring groove 141 and used for sealing cooling water of the first inner cooling water channel.

The protective sleeve 9 is step-shaped, and a first copper gasket 7 for sealing gas is arranged at the contact part of the fuel injector 5 and the step on the inner wall of the protective sleeve 9; and a second copper gasket 8 is arranged at the contact part of the step of the outer wall of the sheath 9 and the edge of the oil sprayer mounting hole 22 and is used for sealing water and gas.

When the engine runs, cooling water enters the first outer cooling water channel 16 from the water inlet 14, the periphery of the exhaust hole 13 is surrounded by the first outer cooling water channel 16, and the cooling water of the first outer cooling water channel is used for cooling high-temperature gas in the exhaust hole 13; and the cooling water of the first outer cooling water channel 16 is divided into two paths: one path of cooling water enters the first inner cooling water channel 30 from the lower water through hole 17, the water in the first inner cooling water channel is used for cooling the cylinder sleeve 2, then the cooling water in the first inner cooling water channel cools the cylinder sleeve 2 through the axial water through hole 24 on the cylinder sleeve 2, and then the cooling water enters the second inner cooling water channel 40 from the axial water through hole 24; the other path of cooling water enters the second inner cooling water channel 40 from the upper water through hole 18; the two paths of cooling water are converged in the second inner cooling water channel 40, enter the second outer cooling water channel 19 through the water hole 10, and then flow out of the cylinder body from the water return hole 15.