An engine with variable compression ratio

Abstract

The present invention discloses an engine with variable compression ratio, which includes a combustion chamber. A piston is connected inside the combustion chamber. A main push block is movably connected inside the piston. The piston is connected with a connecting rod. A connecting rod oil passage is arranged inside the connecting rod. One end of the connecting rod oil passage is connected to the main push block, and the other end communicates with a main oil passage. The present invention provides an engine with variable compression ratio. On the basis of not damaging the traditional connecting rod structure, the compression ratio is controlled by changing the oil pressure, which improves the combustion efficiency. At the same time, the weight of its own structure is reduced, and there is no need for excessive transmission connection structures, which can not only reduce the overall energy loss, but also will not generate high costs during the manufacturing process.

Description

Technical Field

[0001] The present invention relates to the technical field of engines, and particularly to an engine with variable compression ratio. Background Art

[0002] In the structural design of engines, the internal gas in the combustion chamber is compressed by the movement of a reciprocating piston. The ratio between the maximum stroke volume and the minimum stroke volume is the compression ratio. The size of the compression ratio is closely related to the thermal efficiency of the engine itself. Generally, engines adopt a structure with a fixed compression ratio. However, in practical applications, a fixed compression ratio cannot adapt to changes in load. Therefore, a variable compression ratio structure has emerged. Under different load conditions, the compression ratio is changed to improve combustion efficiency. However, the currently relatively mature structure for variable compression ratio is the multi-link structure. This type of structure is more complex than the traditional connecting rod structure, and both its volume and weight have increased. Although it can improve combustion efficiency, its manufacturing cost and energy loss have also increased, and the improvement effect of the overall performance is not obvious.

[0003] For example, the publication number "CN115142950A" discloses "Multi-link structure of variable compression ratio engine, variable compression ratio engine and vehicle", including an upper connecting rod, a rocker arm assembly, a crankshaft, a lower connecting rod, a control shaft, a drive assembly, a hydraulic chamber and an oil inlet and outlet control assembly; the drive assembly is connected to the control shaft, divides the hydraulic chamber into upper and lower hydraulic chambers, and can adjust the volume of the upper and lower hydraulic chambers under the drive of the control shaft; the oil inlet and outlet control assembly is used to control the oil inlet and outlet states of the upper and lower hydraulic chambers. The drive assembly is driven by the power from the piston and has a tendency to change the volumes of the upper and lower hydraulic chambers. The drive assembly reduces the volume of the chamber in the oil outlet state, and the other chamber is filled with oil. When the volume of the chamber in the oil outlet state becomes the smallest, the drive assembly can no longer slide, and the state of the control shaft is stable, realizing reliable compression ratio switching. However, in practical applications, this type of structure greatly increases the weight and structural complexity of the crankshaft itself, resulting in a certain increase in the manufacturing cost of the engine. At the same time, due to the complex and heavy connecting rod structure, more power energy will be lost during movement, and the economic benefits brought by variable compression ratio are not high. Summary of the Invention

[0004] Aiming at the problems in the prior art mentioned in the background art, such as the increase in cost and energy loss caused by the large weight and complex structure of the multi-link structure itself, the present invention provides an engine with variable compression ratio. Without destroying the traditional connecting rod structure, the compression ratio is controlled by changing the oil pressure, which improves the combustion efficiency, reduces the weight of its own structure at the same time, reduces the overall energy loss, and does not generate high manufacturing costs.

[0005] To achieve the above object, the present invention adopts the following technical solutions.

[0006] An engine with variable compression ratio includes a combustion chamber, a piston is connected inside the combustion chamber, a main push block is movably connected inside the piston, the piston is connected with a connecting rod, a connecting rod oil passage is arranged inside the connecting rod, one end of the connecting rod oil passage is connected to the main push block, and the other end communicates with a main oil passage. The piston reciprocates in the combustion chamber, and the connecting rod drives the piston to move. The connecting rod oil passage arranged inside the connecting rod is connected with the main oil passage, so that the engine oil inside the main oil passage can flow into the connecting rod oil passage. The other end of the connecting rod oil passage is connected with the main push block, and the main push block is slidably connected inside the piston. By changing the oil pressure and oil volume inside the main oil passage, the main push block is pushed to move, and then the volume of the entire combustion chamber when the piston runs to the top dead center and the bottom dead center positions is controlled, and the compression ratio is changed to adapt to different load powers, thereby improving the performance of the engine. At the same time, since the connecting rod oil passage is arranged inside the connecting rod, the connecting rod becomes a hollow structure. Compared with the traditional engine, the overall weight is reduced. Compared with the multi-link variable compression ratio structure on the market, the overall structure is more streamlined, and the production cost and manufacturing process are both reduced. The main oil passage is a lubricating oil passage. In the design, it is necessary to control the designed flow rate of the oil pump to be greater than the required flow rate inside the lubrication system to ensure that there is surplus engine oil supplied to the connecting rod oil passage.

[0007] Preferably, a pressure relief valve is arranged inside the piston, and the pressure relief valve is arranged between the main push block and the connecting rod oil passage. The pressure relief valve arranged between the connecting rod oil passage and the main push block can adaptively adjust the main push block to maintain the stability of the pressure inside the combustion chamber. And a monitoring and induction sensor is arranged inside the pressure relief valve, and the detection and induction sensor is feedback-connected to the ECU module. When the difference between the current compression ratio and the target compression ratio deviates from the set value, the monitoring and induction sensor controls the oil pump pumping pressure and flow rate through the ECU to control the variable compression ratio, so as to change the current compression ratio and make the current compression ratio reach the target compression ratio. When the power reaches the required power, pressure relief starts. The compression ratio can change the denominator coefficient of the compression ratio by changing the stroke of the main push block at the top dead center, thereby changing the compression ratio value. At the same time, the molecular coefficient of the compression ratio can also be changed by changing the stroke of the main push block at the bottom dead center, thereby changing the compression ratio value.

[0008] Preferably, an oil outlet is arranged at one end of the connecting rod close to the main push block, the oil outlet is connected to the pressure relief valve, and one end of the pressure relief valve away from the oil outlet abuts against the main push block. The oil outlet is connected to the pressure relief valve, and the engine oil inside the connecting rod oil passage is discharged from the oil outlet to squeeze the pressure relief valve. When the pressure relief valve is squeezed to a certain extent, it starts to push the main push block abutted at the other end to move, thereby changing the stroke volume inside the combustion chamber.

[0009] Preferably, a baffle is connected to one end of the pressure relief valve away from the main push block. The oil outlet includes an upper stepped hole and a lower stepped hole. The diameter of the upper stepped hole is larger than that of the lower stepped hole. The upper stepped hole sleeves the baffle, and an oil hole is provided on the baffle. The baffle provided on the upper stepped hole of the oil outlet can support the pressure relief valve when the oil pressure is low to prevent the pressure relief valve from falling off. At the same time, the oil hole provided on the baffle enables the engine oil to flow through and squeeze the pressure relief valve, thereby changing the stroke change of the main push block.

[0010] Preferably, a slideway is provided inside the main push block. The pressure relief valve includes a telescopic member. The telescopic member is arranged in the slideway. The telescopic member abuts against the baffle, and the oil hole communicates the connecting rod oil passage with the slideway. A slideway is provided inside the main push block. The slideway sleeves the telescopic member, and the elastic telescopic performance of the telescopic member is used to stabilize the air pressure in the combustion chamber, avoiding the situation that when running to the top dead center, the volume in the combustion chamber is too small, resulting in excessive pressure and causing engine block explosion.

[0011] Preferably, the telescopic member includes a sliding pin. The sliding pin is slidably connected to the slideway. An elastic member is sleeved inside the sliding pin, and a jacking bottom plate is provided at the bottom of the sliding pin. The sliding connection between the sliding pin and the slideway ensures the smooth movement of the pressure relief valve. An elastic member is sleeved inside the sliding pin. When the oil pressure rises, the engine oil passes through the oil hole to squeeze the jacking bottom plate, the sliding pin rises and squeezes the elastic member. After the elastic member is compressed by a certain amount, it pushes the main push block upwards, and when the power reaches the required power, pressure relief starts.

[0012] Preferably, an oil passage chamber is provided at the end of the connecting rod. The oil passage chamber communicates with a plurality of oil outlets. The oil passage chamber provided at the end of the connecting rod communicates with a plurality of oil outlets. A pressure relief valve is connected to each oil outlet. The plurality of oil outlets are evenly arranged. Since all are connected to the oil passage chamber, the pressures received by each pressure relief valve are uniform, so that the thrusts received by each part of the main push block are the same, ensuring the smooth movement of the main push block.

[0013] Preferably, an oil pump is further included. The oil pump communicates with the main oil passage. The oil in the oil pump is transmitted to various parts of the engine through the main oil passage for lubrication, and all the lubricating engine oil finally returns to the oil sump and is then pumped into each part that needs lubrication by the oil pump. The oil requirement of the lubrication system is approximately equal to the engine oil flow of each journal. When selecting the oil pump, the oil quantity of the oil pump needs to be higher than the oil requirement of the lubrication system, so as to realize the adjustment of the variable compression ratio system, and the pressure and flow of the oil pump are controlled through the feedback of the monitoring and induction sensor inside the pressure relief valve to change the oil quantity pumped into the connecting rod oil passage, thereby realizing the effect of changing the compression ratio.

[0014] The beneficial effects of the present invention are as follows:

[0015] (1) By connecting the main oil passage to the connecting rod oil passage, the oil in the main oil passage can be diverted into the connecting rod oil passage and squeeze the main push block to change the compression ratio, improving the performance of the engine. At the same time, due to its lighter structure, the fuel consumption is reduced, and the production cost is lower.

[0016] (2) The pressure is maintained and leaked through a pressure relief valve. On the basis of changing the compression ratio, the pressure inside the combustion chamber is kept stable, avoiding cylinder explosion caused by excessive pressure and compression ratio. And real-time feedback is carried out through the built-in monitoring and induction sensor to control the actual compression ratio to reach the target compression ratio. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 is an axonometric view of the present invention.

[0018] Figure 2 is a partial cross-sectional view of the present invention.

[0019] Figure 3 is Figure 2 a schematic structural view of part A in

[0020] In the figure: 1 piston, 2 main push block, 21 slideway, 3 connecting rod, 31 connecting rod oil passage, 32 oil outlet, 33 upper stepped hole, 34 lower stepped hole, 35 oil passage cavity, 4 main oil passage, 5 pressure relief valve, 51 retaining piece, 511 oil hole, 52 telescopic member, 53 sliding pin, 54 elastic member, 55 jacking bottom plate, 6 oil pump, 7 oil pan, 8 filter, 9 crankshaft, 10 camshaft oil passage. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0021] The present invention will be further described below with reference to the drawings and specific embodiments.

[0022] Embodiment 1:

[0023] As Figure 1 , 2 shown, a variable compression ratio engine includes a combustion chamber, a piston 1 is connected inside the combustion chamber, a main push block 2 is slidably connected inside the piston 1, the piston 1 is connected with a connecting rod 3, a connecting rod oil passage 31 is arranged inside the connecting rod 3, one end of the connecting rod oil passage 31 is connected with the main push block 2, the other end is communicated with a main oil passage 4, a pressure relief valve 5 is arranged inside the piston 1, and the pressure relief valve 5 is arranged between the main push block 2 and the connecting rod oil passage 31.

[0024] The piston 1 reciprocates in the combustion chamber, and the connecting rod 3 drives the piston 1 to move. The connecting rod oil passage 31 provided in the connecting rod 3 is connected to the main oil passage 4, enabling the engine oil inside the main oil passage 4 to flow into the connecting rod oil passage 31. The other end of the connecting rod oil passage 31 is connected to the main pusher block 2. The main pusher block 2 is slidably connected inside the piston 1. By changing the oil pressure and oil volume in the main oil passage 4, the main pusher block 2 is pushed to move, thereby controlling the volume of the entire combustion chamber when the piston 1 runs to the top dead center and bottom dead center positions, changing the compression ratio to adapt to different load powers, and thus improving the performance of the engine. At the same time, since the connecting rod oil passage 31 is provided inside the connecting rod 3, the connecting rod 3 becomes a hollow structure. Compared with traditional engines, the overall weight is reduced. Compared with the multi-connecting rod 3 variable compression ratio structures on the market, the overall structure is more streamlined, and both the production cost and manufacturing process are reduced. The main oil passage 4 is a lubricating oil passage. In design, it is necessary to control the designed flow rate of the oil pump 6 to be greater than the flow rate required in the lubrication system to ensure that there is surplus engine oil supplied to the connecting rod oil passage 31. The pressure relief valve 5 provided between the connecting rod oil passage 31 and the main pusher block 2 can adaptively adjust the main pusher block 2 to maintain the stability of the pressure inside the combustion chamber. And a monitoring and induction sensor is provided inside the pressure relief valve 5. The detection and induction sensor is feedback-connected to the ECU module. When the difference between the current compression ratio and the target compression ratio deviates from the set value, the monitoring and induction sensor controls the oil pumping pressure and flow rate of the oil pump 6 through the ECU to control the variable compression ratio, so as to change the current compression ratio to make the current compression ratio reach the target compression ratio. When the power reaches the required power, pressure relief starts. The compression ratio can change the denominator coefficient of the compression ratio by changing the stroke of the main pusher block 2 at the top dead center, thereby changing the compression ratio value. At the same time, the numerator coefficient of the compression ratio can also be changed by changing the stroke of the main pusher block 2 at the bottom dead center, thereby changing the compression ratio value.

[0025] As Figure 2 、 3 shown, an oil passage chamber 35 is provided at the end of the connecting rod 3. The oil passage chamber 35 communicates with a plurality of oil outlets 32. The oil outlets 32 are connected to the pressure relief valve 5. One end of the pressure relief valve 5 away from the oil outlet 32 abuts against the main pusher block 2. A retaining plate 51 is connected to the end of the pressure relief valve 5 away from the main pusher block 2. The oil outlet 32 includes an upper stepped hole 33 and a lower stepped hole 34. The diameter of the upper stepped hole 33 is larger than that of the lower stepped hole 34. The upper stepped hole 33 sleevingly connects the retaining plate 51, and an oil hole 511 is provided on the retaining plate 51.

[0026] The oil outlet 32 is connected to the pressure relief valve 5. The engine oil inside the connecting rod oil passage 31 is discharged from the oil outlet 32 to squeeze the pressure relief valve 5. When the pressure relief valve 5 is squeezed to a certain extent, it starts to push the main push block 2 abutted at the other end to move, thereby changing the stroke volume in the combustion chamber. The retaining piece 51 provided on the upper stepped hole 33 of the oil outlet 32 can support the pressure relief valve 5 when the oil pressure is low to prevent the pressure relief valve 5 from falling off. At the same time, the oil hole 511 provided on the retaining piece 51 enables the engine oil to flow through and squeeze the pressure relief valve 5, thereby changing the stroke change of the main push block 2. There are three oil outlets 32 communicated with the oil passage cavity 35 provided at the end of the connecting rod 3, and a pressure relief valve 5 is connected to each oil outlet 32. The oil outlets 32 are evenly arranged. Since they are all connected to the oil passage cavity 35, the pressures received by the pressure relief valves 5 are uniform, so that the thrusts received by each part of the main push block 2 are the same, ensuring the smooth movement of the main push block 2.

[0027] As Figure 3 shown, a slideway 21 is provided inside the main push block 2. The pressure relief valve 5 includes a telescopic member 52. The telescopic member 52 includes a sliding pin 53. The sliding pin 53 is slidably connected to the slideway 21. An elastic member 54 is sleeved inside the sliding pin 53, and a jacking bottom plate 55 is provided at the bottom of the sliding pin 53.

[0028] A slideway 21 is provided inside the main push block 2. The slideway 21 is sleeved with a telescopic member 52, and the air pressure in the combustion chamber is stabilized through the elastic telescopic performance of the telescopic member 52 to prevent the volume in the combustion chamber from being too small when running to the top dead center, resulting in excessive pressure causing engine knocking. The smooth movement of the pressure relief valve 5 is ensured by the sliding connection between the sliding pin 53 and the slideway 21, and an elastic member 54 is sleeved inside the sliding pin 53. When the oil pressure rises, the engine oil passes through the oil hole 511 to squeeze the jacking bottom plate 55, the sliding pin 53 rises and squeezes the elastic member 54. After the elastic member 54 is compressed by a certain amount, it pushes the main push block 2 upward, and when the power reaches the required power, pressure relief starts.

[0029] As Figure 1 shown, the device further includes an oil pump 6. The oil pump 6 is communicated with the main oil passage 4. The oil in the oil pump 6 is transmitted to various parts of the engine through the main oil passage 4 for lubrication, and all the lubricating engine oil finally returns to the oil sump 7 and is then pumped into each part that needs lubrication by the oil pump 6. The required oil volume of the lubrication system is approximately equal to the engine oil flow rate of each journal. When selecting the oil pump 6, it is necessary to make the oil volume of the oil pump 6 higher than the required oil volume of the lubrication system, so as to realize the adjustment of the variable compression ratio system, and the pressure and flow rate of the oil pump 6 are controlled through the feedback of the monitoring and induction sensor in the pressure relief valve 5 to change the oil volume pumped into the connecting rod oil passage 31, thereby realizing the effect of changing the compression ratio.

[0030] The working process of a variable compression ratio engine in this embodiment is as follows: In this embodiment, the engine oil first enters the oil pump 6 through the oil pan 7, the engine oil of the oil pump 6 enters the filter 8, and then the engine oil enters the main oil gallery 4 through the filter 8, and the engine oil enters the crankshaft 9 through the main oil gallery 4 and enters the camshaft oil gallery 10 at the same time; the engine oil reaches the connecting rod oil gallery 31 through the crankshaft 9 and is transported to the inside of the oil passage chamber 35, and the engine oil passes through the oil hole 511 on the baffle 51 on the oil outlet 32 in the oil passage chamber 35, and squeezes the lifting bottom plate 5 5, drives the sliding pin 53 to move in the slideway 21, and the sliding pin 53 gradually squeezes the elastic member 54. After the elastic member 54 is squeezed to a certain stroke, the elastic member 54 pushes the main push block 2 to rise, and the main push block 2 moves to realize a variable compression ratio. In the continuous movement of the piston 1, when the difference between the current compression ratio and the target compression ratio deviates from the set value, the monitoring induction sensor in the pressure relief valve 5 controls the compression ratio by feeding back to the ECU to control the oil pump 6 pumping oil pressure and flow to control the compression ratio, so that the current compression ratio reaches the target compression ratio.

[0031] In addition to the above-mentioned embodiments, within the scope disclosed in the claims and the specification of the present invention, the technical features of the present invention can be reselected and combined to form new embodiments, which can be achieved by those skilled in the art without creative work. Therefore, these embodiments that are not described in detail in the present invention should also be regarded as specific embodiments of the present invention and within the protection scope of the present invention.

Claims

1. An engine with variable compression ratio, comprising a combustion chamber, wherein a piston is connected in the combustion chamber, and is characterized in that, A main push block is movably connected inside the piston. The piston is connected to a connecting rod. A connecting rod oil passage is provided inside the connecting rod. One end of the connecting rod oil passage is connected to the main push block, and the other end communicates with a main oil passage. A pressure relief valve is provided inside the piston. The pressure relief valve is arranged between the main push block and the connecting rod oil passage. An oil outlet is provided at one end of the connecting rod close to the main push block. A baffle is connected to one end of the pressure relief valve away from the main push block. An oil hole is provided on the baffle. A slideway is provided inside the main push block. The pressure relief valve includes a telescopic member. The telescopic member is arranged in the slideway. The telescopic member includes a sliding pin. An elastic member is sleeved inside the sliding pin. A jacking bottom plate is provided at the bottom of the sliding pin. An oil passage chamber is provided at the end of the connecting rod. Engine oil passes through the oil hole on the baffle of the oil outlet in the oil passage chamber, squeezes the jacking bottom plate, drives the sliding pin to move in the slideway, and the sliding pin gradually squeezes the elastic member. After the elastic member is squeezed to a certain stroke, the elastic member pushes the main push block to rise, and the movement of the main push block realizes a variable compression ratio.

2. The variable compression ratio engine according to claim 1, characterized in that, The oil outlet is connected to the pressure relief valve, and one end of the pressure relief valve away from the oil outlet abuts against the main push block.

3. The variable compression ratio engine according to claim 2, characterized in that, The oil outlet includes an upper stepped hole and a lower stepped hole. The diameter of the upper stepped hole is larger than that of the lower stepped hole. The upper stepped hole sleeves the baffle.

4. A variable compression ratio engine according to claim 3, characterized in that, The telescopic member abuts against the baffle, and the oil hole communicates the connecting rod oil passage with the slideway.

5. A variable compression ratio engine according to claim 4, characterized in that, The sliding pin is slidably connected to the slideway.

6. A variable compression ratio engine according to any one of claims 1-4, characterized in that, A plurality of oil outlets communicate with the oil passage chamber.

7. A variable compression ratio engine according to any one of claims 1-4, characterized in that, An oil pump is further included, and the oil pump communicates with the main oil passage.

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