Four-stroke internal combustion engine cylinder
By installing a cooling shell and a pneumatic piston on the outer wall of a single-cylinder internal combustion engine, the cooling water cycle is used to achieve efficient heat dissipation and fuel utilization, which solves the problem of low heat dissipation and fuel utilization of the single-cylinder internal combustion engine, and improves the working stability and fuel combustion efficiency of the internal combustion engine.
Patent Information
- Application Number
- CN202111058638.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2021-09-10
- Publication Date
- 2025-01-03
- Estimated Expiration
- 2041-09-10
AI Technical Summary
Single-cylinder internal combustion engines cannot achieve efficient heat dissipation and full fuel utilization, resulting in insufficient intake air, reduced power and material damage, and at the same time, the insufficient combustion fuel exhaust gas is seriously polluted.
A four-stroke internal combustion engine cylinder is designed to form a chamber by placing an annular cooling shell on the outer wall of the cylinder body, absorbing heat by cooling water, and efficient heat dissipation by using the large specific heat capacity of water, and cooling is achieved during the operation of the internal combustion engine through a pneumatic piston. Water circulation reduces exhaust gas emissions.
It realizes efficient heat dissipation of a single-cylinder internal combustion engine, improves fuel utilization, reduces the adverse impact of high temperature on the structure, reduces air pollution, and improves the service life and stability of the cylinder.
Smart Images
Figure CN113847158B_ABST
Abstract
Description
Technical Field
[0001] The invention belongs to the field of power machinery, in particular to a four-stroke internal combustion engine cylinder. Background Art
[0002] The cylinder of a four-stroke internal combustion engine is a cylindrical metal part that guides the piston to perform linear reciprocating motion in the cylinder. The internal combustion engine usually refers to a piston internal combustion engine. The piston internal combustion engine is the most common in which the piston reciprocates in the cylinder. It mixes fuel and air, burns in the cylinder, and the heat energy released generates high-temperature and high-pressure combustion gas in the cylinder. The expansion of the combustion gas pushes the piston to work, and then the mechanical work is output through the crank-connecting rod mechanism or other mechanisms to drive the driven machine to work. The conversion of heat energy and mechanical energy in the internal combustion engine completes a working cycle through the four processes of continuous intake, compression, power and exhaust of the piston in the cylinder. Internal combustion engines are widely used in power generation, military, construction, shipbuilding and other fields due to their large output torque and stable power.
[0003] As the main component of the internal combustion engine, limited by the structure, materials and working principle of the internal combustion engine in the existing technology, the current single-cylinder internal combustion engine cannot achieve efficient heat dissipation and full utilization of fuel. The fuel utilization rate can only reach 46% at most. The fuel that is not fully burned will be discharged as exhaust gas and cause huge pollution to the air. Moreover, the heat that cannot be dissipated will overflow and cause the temperature of the cylinder to rise. The high temperature may cause insufficient air intake in the cylinder, resulting in a decrease in output power, and even cause material deformation and damage.
[0004] In view of this, in order to overcome the above technical problems, the present invention designs a four-stroke internal combustion engine cylinder to solve the above technical problems. Summary of the invention
[0005] The technical problem to be solved by the present invention is: a four-stroke internal combustion engine cylinder provided by the present invention improves the heat dissipation capacity and fuel utilization rate of a single-cylinder internal combustion engine, thereby avoiding insufficient air intake of the internal combustion engine, power reduction, and even material deformation and damage due to high temperature, while reducing the amount of incompletely burned fuel exhaust entering the air, thereby reducing the huge pollution to the air.
[0006] A four-stroke internal combustion engine cylinder provided by the present invention comprises a cylinder body, a combustion chamber, a piston, a pin hole, a piston pin, a connecting rod, a crankshaft and a flywheel, wherein a piston is slidably mounted in the cylinder body; a pin hole is provided at the lower end of the piston; the pin hole is coaxially mounted with an opening at the upper end of the connecting rod, and a rotational connection between the piston and the connecting rod is achieved by inserting the piston pin into the pin hole; the lower end of the connecting rod is rotationally connected to the crankshaft through a bearing; one end of the crankshaft is fixedly connected to the flywheel, and drives the flywheel to rotate together when the crankshaft rotates; an annular cooling shell is provided outside the cylinder body; an annular groove is provided on the outer wall of the cylinder body; an annular groove is inserted into the cooling shell The groove is closed with the outer surface of the cylinder body to form a chamber; the corners of the cooling shell are rounded; the cooling shell wall is provided with threaded holes; the upper end of the cooling shell is provided with a water supply pipe with one end connected to the water inlet and the other end connected to the chamber; the lower end of the cooling shell is provided with a drainage pipe with one end connected to the drainage port and the other end connected to the bottom of the chamber; the drainage port and the water inlet are externally connected to the same water tank; the upper end of the cylinder body is provided with a combustion chamber; the inner wall of the combustion chamber is provided with a through hole that penetrates the cylinder body and the cooling shell; a pneumatic piston is coaxially slidably mounted inside the through hole; the length of the pneumatic piston is less than the length of the through hole.
[0007] Preferably, limiting blocks are provided at both ends of the through hole; and the inner surfaces of the limiting blocks are fixedly connected to buffer pads.
[0008] Preferably, both the drainage pipe and the water supply pipe are provided with a one-way valve; the water inlet of the one-way valve in the water supply pipe is communicated with the water inlet; the water inlet of the one-way valve in the drainage pipe is communicated with the chamber.
[0009] Preferably, the bottom of the chamber is inclined and the lower part is connected to the bottom end of the drainage pipe.
[0010] Preferably, the pneumatic piston is made of high-temperature ceramic material.
[0011] Preferably, a valve is provided at the top of the cylinder body; the valve is spherical.
[0012] The beneficial effects of the present invention are as follows:
[0013] The present invention provides a four-stroke internal combustion engine cylinder, which forms a chamber by arranging a cooling shell in the outer wall of the cylinder body, and utilizes the large specific heat capacity of water to absorb heat. When the internal combustion engine is working, cooling water is injected into the chamber to absorb the heat of the cylinder body. The water pressure and the pressure of the piston in the cylinder body can realize the reciprocating motion of the pneumatic piston, and then the cooling water can be switched on and off to enter the chamber through the working process of the internal combustion engine itself and the circulation of the cooling water in the chamber can be promoted. No external power source is required to achieve efficient heat dissipation of the single cylinder, reduce the adverse effects of high temperature on fuel utilization and the structure of the internal combustion engine, and thus ensure that the cylinder body is in a normal working state. BRIEF DESCRIPTION OF THE DRAWINGS
[0014] The present invention will be further described below in conjunction with the accompanying drawings.
[0015] Figure 1 It is an overall schematic diagram of the present invention;
[0016] Figure 2 It is a partial enlarged view of the present invention;
[0017] Figure 3 is an enlarged view of the drainage end of the present invention;
[0018] In the figure: cylinder 1, combustion chamber 101, through hole 102, water pipe 103, drainage pipe 104, groove 105, limit block 106, piston 2, pin hole 201, piston pin 202, crank 3, flywheel 4, cooling shell 5, drainage port 6, pneumatic piston 7, water inlet 8, valve 9, chamber 10, threaded hole 11, buffer pad 12, one-way valve 13, crankshaft 14. DETAILED DESCRIPTION
[0019] In order to make the technical means, creative features, objectives and effects achieved by the present invention easy to understand, the present invention is further explained below in conjunction with specific implementation methods.
[0020] A four-stroke internal combustion engine cylinder provided by the present invention comprises a cylinder body 1, a combustion chamber 101, a piston 2, a pin hole 201, a piston pin 202, a connecting rod 3, a crankshaft 14 and a flywheel 4, wherein a piston 2 is slidably mounted in the cylinder body 1; a pin hole 201 is provided at the lower end of the piston 2; the pin hole 201 is coaxially mounted with an opening at the upper end of the connecting rod 3, and the piston 2 and the connecting rod 3 are rotatably connected by inserting the piston pin 202 into the pin hole 201; the lower end of the connecting rod 3 is rotatably connected to the crankshaft 14 through a bearing; one end of the crankshaft 14 is fixedly connected to the flywheel 4, and drives the flywheel 4 to rotate together when the crankshaft 14 rotates; an annular cooling shell 5 is provided on the outer jacket of the cylinder body 1; an annular groove 105 is provided on the outer wall of the cylinder body 1; the cooling shell 5 is inserted into an annular groove 105 ... The shaped groove 105 is closed with the outer surface of the cylinder body 1 to form a chamber 10; the corners of the cooling shell 5 are rounded; the wall of the cooling shell 5 is provided with a threaded hole 11; the upper end of the cooling shell 5 is provided with a water supply pipe 103, one end of which is connected to the water inlet 8 and the other end is connected to the chamber 10; the lower end of the cooling shell 5 is provided with a drainage pipe 104, one end of which is connected to the drain port 6 and the other end is connected to the bottom of the chamber 10; the drain port 6 and the water inlet 8 are externally connected to the same water tank; the upper end of the cylinder body 1 is provided with a combustion chamber 101; the inner wall of the combustion chamber 101 is provided with a through hole 102 that passes through the cylinder body 1 and the cooling shell 5; a pneumatic piston 7 is coaxially slidably installed inside the through hole 102; the length of the pneumatic piston 7 is less than the length of the through hole 102.
[0021] By inserting two semi-annular cooling shells 5 into the annular external groove 105 of the cylinder body 1, and fastening the cooling shells 5 together with bolts through the threaded holes 11 set on the two semi-annular shells, the production difficulty is reduced, and the annular cooling shell 5 is installed along the annular groove 105 on the outer wall of the cylinder body 1. The annular cooling shell 5 is embedded in the groove 105, which not only makes the cooling shell 5 fastened by bolts more firmly installed on the outer wall of the cylinder body 1, but also prevents the cooling shell 5 from longitudinally displacing on the outer wall of the cylinder body 1 due to external factors such as vibration, but also improves the sealing of the chamber 10 formed by the inner surface of the cooling shell 5 and the outer surface of the cylinder body 1.
[0022] When the internal combustion engine is working, the water inlet 8 at the upper end of the cooling shell 5 will use a pipe to absorb water from the water tank and fill the chamber 10 with cooling water through the water pipe 103. When the internal combustion engine enters the compression stroke, the valve 9 on the top of the cylinder 1 is closed, and the inner wall of the cylinder 1 and the piston 2 form a closed space. Under the residual work of the previous power stroke and the inertia of the flywheel 4, the piston 2 moves upward along the inner wall of the cylinder 1 to compress the air. At the same time, because of the energy released by the previous power stroke and the piston 2 The frequent and rapid reciprocating motion and friction will increase the temperature of the cylinder wall of the cylinder body 1. In the closed space, the cylinder body 1 compresses the air due to the piston 2, causing the air pressure in the cylinder to increase. The high air pressure will push the pneumatic piston 7 coaxially slidably installed inside the through hole 102 to move into the chamber 10 and compress the volume of the cooling water in the chamber 10, thereby forcing part of the cooling water to be discharged from the drain port 6 through the drain pipe 104 at the bottom of the chamber 10. The discharged cooling water then returns to the water tank through an external pipe, thereby realizing the reuse of the cooling water.
[0023] After the compression stroke, the power stroke begins. The valve 9 on the top of the cylinder 1 is still closed, and the inner wall of the cylinder 1 and the piston 2 form a closed space. Under the action of the fuel injector and the spark plug, the fuel burns explosively in the compressed air, causing the gas to expand violently and produce a higher instantaneous gas pressure. The gas pushes the piston 2 downward to drive the flywheel 4 to transmit power and continue to support the pneumatic piston 7 to move forward to the end of the through hole 102 close to the chamber 10, approximately maintaining the position state of the pneumatic piston 7 in the through hole 102 during the compression stroke.
[0024] After that, it enters the exhaust stroke, and the exhaust valve 9 opens. At this time, the cylinder 1 is not in a sealed state. Under the residual work of the power stroke and the inertia of the flywheel 4, the piston 2 that moves to the bottom of the cylinder 1 to complete the power transmission will move upward along the cylinder 1, and then squeeze the space in the cylinder 1 to discharge the exhaust gas in the cylinder 1. At this time, after losing the constraint of the high-pressure gas in the power stroke, the pneumatic piston 7 will move to the side of the cylinder 1 in the through hole 2 under the action of the pressure of the cooling water in the chamber 10 and the steam pressure generated when the cooling water contacts the high-temperature cylinder wall. In the process of movement, negative pressure is generated in the chamber 10, and then cooling water is sucked from the external water tank through the water inlet 8 through the water pipe 103. At the same time, the piston 2 at the bottom of the cylinder 1 cooperates with the exhaust gas to squeeze the cylinder 1 out of the cylinder, thereby improving the efficiency and speed of the exhaust of the cylinder 1 in the exhaust stroke, thereby reducing the exhaust gas mixed in the cylinder 1 in the next intake stroke, and further improving the combustion efficiency of the fuel.
[0025] During the intake stroke, the intake valve 9 opens. At this time, the cylinder body is not in a sealed state. Under the action of the residual work of the power stroke and the inertia of the flywheel 4, the piston 2 moves downward along the inner wall of the cylinder body 1 to inhale air. At this time, under the action of the water pressure, steam pressure in the chamber 10 and the negative pressure in the cylinder body 1, the pneumatic piston 7 approximately maintains the position state of the pneumatic piston 7 in the through hole 102 during the exhaust stroke, and then waits for the next compression stroke.
[0026] The corners of the cooling shell 5 are rounded to improve the structural strength of the chamber 10 , avoid structural damage to the chamber 10 due to excessive pressure difference or excessive stress concentration in the chamber 10 , and increase the service life of the cooling shell 5 .
[0027] Compared with the water cooling and air cooling methods used in traditional single-cylinder engines, a cooling shell 5 is arranged outside the cylinder body 1. By utilizing the large specific heat capacity of water, the cooling water is directly brought into contact with the high-temperature cylinder body 1, and the heat is taken away efficiently. At the same time, the positive and negative pressure changes caused by different strokes inside the cylinder body 1 are further utilized in conjunction with the water pressure and steam pressure in the chamber 10 to realize the reciprocating movement of the pneumatic piston 7 in the through hole 102, thereby realizing the extraction and discharge of the cooling water in the chamber 10, and realizing the replacement and flow of the cooling water in the chamber 10 without an external power device, thereby further improving the cooling effect, thereby improving the service life, stability and fuel utilization of the cylinder. At the same time, in order to ensure that no excessive external vibration is generated during the cooling process and to improve the stability of the chamber 10, two pneumatic pistons 7 are symmetrically installed on both sides of the cylinder body 1.
[0028] As a specific embodiment of the present invention, two ends of the through hole 102 are provided with limit blocks 106; the inner surface of the limit block 106 is fixedly connected to the buffer pad 12;
[0029] Whether it is the air pressure inside the cylinder body 1 or the water pressure and steam pressure in the chamber 10, a large force will be generated in the confined space to push the pneumatic piston 7 to move. In order to ensure that the displacement distance of the pneumatic piston 7 will not affect the normal operation of the cylinder and the chamber 10, limit blocks 106 are set at both ends of the through hole 102 to limit the displacement range of the pneumatic piston 7, so that the pneumatic piston 7 is always located in the through hole 102 and will not interfere with the normal operation of the cylinder. At the same time, in order to avoid the impact between the pneumatic piston 7 and the limit block 106 under the action of pressure to damage the structure of the pneumatic piston 7 and the limit block 106, a buffer pad 12 is provided on the impact surface of the limit block 106 and the pneumatic piston 7, thereby buffering and weakening the impact of the pneumatic piston 7 on the limit block 106, reducing vibration, and thus improving the service life and working stability of the pneumatic piston 7.
[0030] As a specific embodiment of the present invention, a one-way valve 13 is provided inside the drainage pipe 104 and the water delivery pipe 103; the water inlet of the one-way valve 13 in the water delivery pipe 103 is communicated with the water inlet 8; the water inlet of the one-way valve 13 in the drainage pipe 104 is communicated with the chamber 10;
[0031] In order to circulate the cooling water in the chamber 10 under the action of the pneumatic piston 7, a one-way valve 13 is provided in the drainage pipe 104 and the water supply pipe 103 to ensure that when there is a positive pressure in the chamber 10, the one-way valve 13 of the water supply pipe 103 is closed and the one-way valve 13 of the drainage pipe 104 is opened, thereby discharging part of the cooling water that has absorbed heat; and when there is a negative pressure in the chamber 10, the one-way valve 13 of the water supply pipe 103 is opened and the one-way valve 13 of the drainage pipe 104 is closed, and the negative pressure will absorb new cooling water with low temperature from the water supply pipe 103, thereby ensuring the realization of the cooling water circulation effect in the chamber 10 and improving the cooling efficiency.
[0032] As a specific embodiment of the present invention, the bottom of the chamber 10 is inclined and the lower part is connected to the bottom end of the drainage pipe 104.
[0033] The bottom of the chamber 10 is provided with a slope which is the same as the drainage pipe 104, so that the cooling water or water vapor after partial heat absorption can flow out more smoothly from the drainage port 5 along the drainage pipe 106 under the action of gravity or pressure. The drainage port 5 can be connected to an external water tank so that the cooling water can be reused.
[0034] As a specific embodiment of the present invention, the pneumatic piston 7 is made of high-temperature ceramic material;
[0035] According to the main chemical composition of the material, high temperature ceramics can be divided into high temperature oxide ceramics (such as Al2O3, ZrO, MgO, CaO, ThO2, Cr2O3, SiO2, BeO, 3Al2O3·2SiO2, etc.), carbide ceramics, boride ceramics, nitride ceramics and silicide ceramics, etc., which are usually resistant to high temperature, high strength, high hardness, good electrical properties, thermal properties and chemical stability. In order to make the coordination between the water pressure and steam in the chamber 10 and the air pressure inside the cylinder body 1 to efficiently realize the displacement drive of the pneumatic piston 7, Cr2O3 high temperature oxide ceramics with light weight and high temperature, high pressure, wear resistance and sealing performance that meet the requirements of the working environment are selected as the manufacturing material of the pneumatic piston 7, which not only reduces the negative impact of the large resistance caused by excessive dead weight on the working effect of the pneumatic piston 7 and the improvement of the working efficiency of the cylinder, but also ensures that the pneumatic piston 7 can work normally in such a high-intensity and high-density working environment, thereby improving the service life and stability of the cylinder and the pneumatic piston 7.
[0036] As a specific embodiment of the present invention, the valve 9 at the upper end of the cylinder body 1 is set to be spherical;
[0037] The two valve valves 9 at the upper end of the cylinder body 1 are set to be spherical. Compared with the flat valves and hemispherical valves in the prior art, the spherical curved surface is more in line with fluid dynamics, making the cylinder smoother during the intake and exhaust process, shortening the time required for intake and exhaust, and improving the working efficiency of the cylinder.
[0038] Working principle: An annular cooling shell 5 is installed along the annular groove 105 on the outer wall of the cylinder body 1, and a closed chamber 10 is formed between the inner surface of the cooling shell 5 and the outer surface of the cylinder body 1. When the internal combustion engine is working, the water inlet 8 at the upper end of the cooling shell 5 will fill the chamber 10 with cooling water through the water pipe 103. When entering the compression stroke of the internal combustion engine, the valve valve 9 on the top of the cylinder body 1 is closed, and the inner wall of the cylinder body 1 and the piston 2 form a closed space. Under the action of the residual work of the previous power stroke and the inertia of the flywheel 4, the piston 2 moves upward along the inner wall of the cylinder body 1 to compress the air and cause the air pressure in the cylinder to increase. The high air pressure will push the pneumatic piston 7 coaxially slidably installed inside the through hole 102 to move into the chamber 10 and compress the volume of the cooling water in the chamber 10, thereby forcing part of the cooling water to be discharged from the drain port 6 through the drain pipe 104 at the bottom of the chamber 10.
[0039] During the power stroke, the valve 9 on the top of the cylinder 1 is still closed, and the inner wall of the cylinder 1 and the piston 2 form a closed space. Under the action of the fuel injector and the spark plug, the fuel burns explosively in the compressed air, causing the gas to expand violently and produce a higher instantaneous gas pressure. The gas pushes the piston 2 downward to drive the flywheel 4 to transmit the power and also continues to support the pneumatic piston 7 to move forward to the end of the through hole 102 close to the chamber 10, approximately maintaining the position state of the pneumatic piston 7 in the through hole 102 during the compression stroke. After that, it enters the exhaust stroke, and the exhaust valve valve 9 opens. At this time, the cylinder 1 is not in a sealed state. Under the residual work of the power stroke and the inertia of the flywheel 4, the piston 2 that moves to the bottom of the cylinder 1 to complete the power transmission will move upward along the cylinder 1, thereby squeezing the space in the cylinder 1 to discharge the exhaust gas in the cylinder 1. At this time, after losing the constraint of the high-pressure gas in the power stroke, the pneumatic piston 7 will move to the side of the cylinder 1 in the through hole 2 under the action of the pressure of the cooling water in the chamber 10 and the steam pressure generated when the cooling water contacts the high-temperature cylinder wall. In the process of movement, negative pressure is generated in the chamber 10, and then cooling water is sucked from the external water tank through the water inlet 8 through the water pipe 103. At the same time, the piston 2 at the bottom of the cylinder 1 squeezes the exhaust gas out of the cylinder 1, thereby improving the efficiency and speed of the exhaust of the cylinder 1 in the exhaust stroke, thereby reducing the exhaust gas mixed in the cylinder 1 in the next intake stroke. The combustion efficiency of the fuel is improved in one step. In the intake stroke, the intake valve 9 is opened. At this time, the cylinder is not in a sealed state. Under the residual work of the power stroke and the inertia of the flywheel 4, the piston 2 moves downward along the inner wall of the cylinder 1 to inhale air. At this time, under the action of the water pressure, steam pressure and negative pressure in the chamber 10, the pneumatic piston 7 approximately maintains the position state of the pneumatic piston 7 in the through hole 102 during the exhaust stroke, and then waits for the next compression stroke. The above process utilizes the principle of pressure difference to realize the reciprocating movement of the pneumatic piston 7 and combines the structural characteristics of the one-way valve 13 to realize the extraction and discharge of cooling water in the chamber 10, thereby realizing an automatic circulation of cooling water, ensuring that the cooling water can smoothly take away the absorbed heat and automatically replenish new cooling water, thereby realizing efficient heat dissipation of the cylinder, improving work efficiency and reducing the negative effects of high temperature on the cylinder.
[0040] The above shows and describes the basic principles, main features and advantages of the present invention. It should be understood by those skilled in the art that the present invention is not limited to the above embodiments. The above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, which fall within the scope of the present invention. The scope of protection of the present invention is defined by the attached claims and their equivalents.
Claims
1. A four-stroke internal combustion engine cylinder, comprising a cylinder body (1), a combustion chamber (101), a piston (2), a pin hole (201), a piston pin (202), a connecting rod (3), a crankshaft (14) and a flywheel (4), characterized in that: The top of the cylinder body (1) is provided with a valve (9); the valve valve (9) is spherical; a piston (2) is slidably mounted in the cylinder body (1); a pin hole (201) is provided at the lower end of the piston (2); the pin hole (201) is coaxially mounted with an opening at the upper end of the connecting rod (3), and a piston pin (202) is inserted into the pin hole (201) to realize a rotational connection between the piston (2) and the connecting rod (3); the lower end of the connecting rod (3) is rotationally connected to the crankshaft (14) via a bearing; one end of the crankshaft (14) is fixedly connected to the flywheel (4), and when the crankshaft (14) rotates, the flywheel (4) is driven to rotate together; The cylinder body (1) is provided with an annular cooling shell (5) on its outer wall; an annular groove (105) is provided on the outer wall of the cylinder body (1); the cooling shell (5) is inserted into the annular groove (105) and is closed with the outer surface of the cylinder body (1) to form a chamber (10); the bottom of the chamber (10) is inclined and the lower part is connected to the bottom end of the drainage pipe (104); the corners of the cooling shell (5) are rounded; a threaded hole (11) is provided on the shell wall of the cooling shell (5); the upper end of the cooling shell (5) is provided with an end communicating with the water inlet (8) and A water delivery pipe (103) whose other end is in communication with the chamber (10); a drainage pipe (104) whose one end is in communication with the drainage port (6) and whose other end is in communication with the bottom of the chamber (10) is provided at the lower end of the cooling shell (5); a one-way valve (13) is provided inside the drainage pipe (104) and the water delivery pipe (103); the water inlet of the one-way valve (13) in the water delivery pipe (103) is in communication with the water inlet (8); the water inlet of the one-way valve (13) in the drainage pipe (104) is in communication with the chamber (10); The outsides of the water outlet (6) and the water inlet (8) are respectively connected to the same water tank via pipes; a combustion chamber (101) is provided at the upper end of the cylinder body (1); a through hole (102) penetrating the cylinder body (1) and the cooling shell (5) is provided on the inner wall of the combustion chamber (101); a pneumatic piston (7) is coaxially slidably mounted inside the through hole (102); the pneumatic piston (7) is shorter than the length of the through hole (102) and is made of high-temperature ceramic material; and limit blocks (106) are provided at both ends of the through hole (102); the inner surface of the limit block (106) is fixedly connected to a buffer pad (12).