Valve clearance compensation mechanism and engine

Abstract

The application relates to the technical field of engines, in particular to a valve clearance compensation mechanism and an engine, which comprises a hydraulic tappet body, the hydraulic tappet body comprises a low-pressure cavity and a high-pressure cavity for storing machine oil, a pressure accumulation cylinder is arranged on the side wall of the hydraulic tappet body, a pressure accumulation chamber is formed in the pressure accumulation cylinder, the pressure accumulation chamber is communicated with the low-pressure cavity, a pressure accumulation piston and a pre-pressing spring are arranged in the pressure accumulation chamber, one end of the pressure accumulation piston is connected with the pre-pressing spring, and the other end of the pressure accumulation piston is in contact with machine oil of the low-pressure cavity. The valve clearance compensation mechanism and the engine can prevent the collapse of a tappet due to instantaneous oil shortage.

Description

Technical Field

[0001] This invention relates to the field of engine technology, and in particular to a valve clearance compensation mechanism and an engine. Background Technology

[0002] The valve train of an internal combustion engine is one of the key systems ensuring its normal operation. In four-stroke engines, to ensure that the valves close tightly when hot, an appropriate valve clearance is usually reserved in the valve train drivetrain. However, the presence of valve clearance can cause impact noise and accelerate the wear of parts. To eliminate this drawback, some engines use a valve clearance compensation mechanism, also known as a hydraulic tappet. This mechanism utilizes the incompressibility of engine oil to automatically absorb dimensional changes in the drivetrain, keeping the valve clearance at zero, thereby reducing noise and eliminating the need for manual adjustment.

[0003] However, the aforementioned hydraulic clearance compensation mechanisms are mostly used in automobile engines, and directly applying them to motorcycle engines presents new technical challenges. For example, motorcycles operate under unique conditions, especially when cornering, where the motorcycle leans, potentially causing a temporary lack of oil in the oil pump. This results in a momentary drop in oil pressure, causing the valve clearance compensation mechanism to immediately deflate and soften, failing to effectively compensate for valve clearance. This leads to impact noise and accelerated wear of components. Therefore, developing an improved valve clearance compensation mechanism that prevents tappet collapse due to momentary oil shortage, specifically tailored to the lubrication characteristics of motorcycle engines during cornering, has become a pressing technical problem in this field. Summary of the Invention

[0004] In order to solve the problems existing in the prior art, this application provides a valve clearance compensation mechanism and an engine.

[0005] The valve clearance compensation mechanism provided by this invention adopts the following technical solution: A valve clearance compensation mechanism includes a hydraulic tappet body, the hydraulic tappet body comprising a low-pressure chamber and a high-pressure chamber for storing engine oil, characterized in that an accumulator cylinder is provided on the side wall of the hydraulic tappet body, an accumulator chamber is formed inside the accumulator cylinder, the accumulator chamber is connected to the low-pressure chamber, an accumulator piston and a preload spring are provided inside the accumulator chamber, one end of the accumulator piston is connected to the preload spring and the other end is in contact with the engine oil in the low-pressure chamber.

[0006] Preferably, the hydraulic tappet body includes a housing and a telescopic body disposed within the housing along the central axis. The telescopic body includes a plunger and a cylinder that are telescopically connected. The top of the plunger abuts against the top surface of the housing, and the bottom of the plunger is connected to the cylinder by a first spring. The plunger is also provided with a one-way valve. The oil in the low-pressure chamber enters the high-pressure chamber through the one-way valve, and the oil in the high-pressure chamber returns to the low-pressure chamber through the gap between the plunger and the cylinder. The low-pressure chamber is formed between the plunger and the housing, and the high-pressure chamber is formed between the plunger and the cylinder.

[0007] Preferably, the port of the accumulator is provided with a one-way throttle valve, which makes the oil filling rate of the accumulator lower than the oil draining rate.

[0008] Preferably, the one-way throttle valve includes a one-way valve diaphragm and a throttle orifice. The one-way valve diaphragm covers the port of the accumulator. The one-way valve diaphragm is closed when oil enters the accumulator and is opened when oil drains from the accumulator. The throttle orifice is opened parallel to the port of the accumulator at the same end of the accumulator.

[0009] Preferably, an adjusting piston is provided in the accumulator chamber, the preload spring is connected between the adjusting piston and the accumulator piston, the adjusting piston is rotatably connected to an adjusting screw, and the adjusting screw is threadedly connected to the end of the accumulator cylinder.

[0010] Preferably, the throttling orifice is radially movably provided with an adjusting rod, the adjusting rod being used to control the minimum passing cross section of the throttling orifice, and a control component being connected between the adjusting rod and the adjusting piston. The adjusting rod increases the minimum passing cross section of the throttling orifice as the adjusting piston retracts, and decreases the minimum passing cross section of the throttling orifice as the adjusting piston moves forward.

[0011] Preferably, the control component includes a hydraulic line formed inside the cylinder wall of the accumulator cylinder. The hydraulic line is provided with a front control piston and a rear control piston. The front control piston is farther away from the adjusting rod than the rear control piston. A connecting rod connects the front control piston and the adjusting piston. The rear control piston is connected to the adjusting rod. The front control piston releases the hydraulic line as the adjusting piston retracts, and the front control piston compresses the hydraulic line as the adjusting piston moves forward.

[0012] Preferably, the hydraulic pipeline is divided into a front pipeline and a rear pipeline, the front control piston is disposed in the front pipeline, the rear control piston is disposed in the rear pipeline, and the cross-section of the front pipeline is smaller than the cross-section of the rear pipeline.

[0013] Preferably, a gasket is provided on the side of the adjusting piston facing the accumulator piston, and the gasket is a high expansion coefficient gasket.

[0014] The engine provided by this invention adopts the following technical solution: An engine employing the aforementioned valve clearance compensation mechanism.

[0015] The beneficial effects of this invention are as follows: During normal operation, the valve clearance compensation mechanism of this invention utilizes the accumulator piston and preload spring in the accumulator chamber to slowly accumulate pressure. When the oil pump sucks in air, the oil pressure in the low-pressure chamber drops instantly to below the accumulator piston's pressure. Therefore, the preload spring pushes the oil in the accumulator chamber out into the low-pressure chamber and into the high-pressure chamber of the cylinder through a one-way valve. This ensures that even if the oil pump briefly sucks in air, there is still a pressurized oil source in the low-pressure chamber to replenish the high-pressure chamber, preventing adverse effects caused by the hydraulic tappet body failing to properly compensate for valve clearance. Attached Figure Description

[0016] Figure 1 This is a cross-sectional view of the valve clearance compensation mechanism in the embodiments of this application; Figure 2 yes Figure 2 A schematic diagram of a local structure in the image; Figure 3 This is a cross-sectional view of the accumulator cylinder in the embodiment of this application.

[0017] Explanation of reference numerals in the attached drawings: 1. Housing; 11. Oil inlet; 12. Oil groove; 13. First oil reservoir; 2. Plunger; 21. Second oil reservoir; 3. Oil cylinder; 31. First spring; 32. High-pressure chamber; 41. Mounting base; 42. Ball; 43. Second spring; 5. Accumulator cylinder; 51. Accumulator chamber; 52. Accumulator piston; 53. Preload spring; 61. One-way valve diaphragm; 62. Throttling orifice; 621. Adjusting rod; 7. Adjusting piston; 71. Adjusting screw; 72. Connecting rod; 8. Hydraulic pipeline; 81. Front control piston; 82. Rear control piston; 9. Gasket. Detailed Implementation

[0018] The following will combine Figures 1-3 The present invention will be further illustrated by the embodiments.

[0019] This embodiment discloses a valve clearance compensation mechanism.

[0020] Reference Figure 1 The hydraulic tappet includes a housing 1 and a telescopic body arranged along the central axis inside the housing 1. The top of the housing 1 is used to contact the cam or rocker arm of the engine valve train, and the bottom of the telescopic body is used to contact the valve pushrod.

[0021] Reference Figure 1 The telescopic body includes a plunger 2 and a cylinder 3 that are telescopically connected. The cylinder 3 is a hollow structure with an open top. The plunger 2 is a structure with both ends open and the channels at both ends are wide and the middle channel is narrow. The plunger 2 is slidably installed at the top opening of the cylinder 3. The outer wall of the plunger 2 and the inner wall of the cylinder 3 are in clearance fit, so that the oil in the cylinder 3 can slowly leak out.

[0022] Reference Figure 1 A first spring 31 is connected between the bottom of the plunger 2 and the inner bottom surface of the cylinder 3. The first spring 31 is in a compressed state between the plunger 2 and the cylinder 3, and the first spring 31 makes the plunger 2 and the cylinder 3 have an automatic tendency to extend.

[0023] Reference Figure 1 The plunger 2 is equipped with a one-way valve, which includes a mounting seat 41, a ball 42, and a second spring 43. The mounting seat 41 is located at the bottom of the plunger 2 and is pressed by the first spring 31. In addition to the top opening, the mounting seat 41 also has through holes on its side walls and / or bottom, allowing oil to pass through. The ball 42 is located inside the mounting seat 41, and the diameter of the ball 42 is larger than the width of the middle channel of the plunger 2, so that the ball 42 can block the plunger 2 under the oil pressure of the cylinder 3. The second spring 43 is located inside the mounting seat 41 and presses against the ball 42.

[0024] Reference Figure 1 The outer wall of the hydraulic cylinder 3 slides against the inner wall of the housing 1. The hydraulic cylinder 3 is equipped with a retaining ring to prevent it from slipping off the housing 1. The top of the plunger 2 abuts against the inner top surface of the housing 1. When the telescopic body extends or retracts, it pushes the housing 1 through the plunger 2. Furthermore, the housing 1 has an oil inlet hole 11, which is used to connect to the engine's lubrication system, allowing the oil pump to continuously pump oil into the hydraulic tappet body. The inner top surface of the housing 1 also has an oil groove 12, which allows oil to enter the plunger 2.

[0025] Based on the above structure, the working principle of the valve clearance compensation mechanism is as follows: When there is valve clearance between the hydraulic tappet body and the cam or rocker arm, the cylinder 3 will move downward under the action of the first elastic element, causing the hydraulic tappet body to extend, thereby eliminating the valve clearance and maintaining good contact between the hydraulic tappet body and the cam or rocker arm. This avoids impact noise caused by the presence of valve clearance. At the same time, as the cylinder 3 moves downward, the volume inside the cylinder 3 increases, the one-way valve opens, and oil enters the cylinder 3 through the plunger 2 until the cylinder 3 is filled with oil again. At this time, the oil pressure at the upper and lower ends of the plunger 2 will be balanced again, and the one-way valve will close again.

[0026] When the valve train is working, the one-way valve closes the plunger 2, preventing the oil in the cylinder 3 from flowing out through the interior of the plunger 2. Simultaneously, the oil in the cylinder 3 cannot quickly leak from the side wall gap between the plunger 2 and the cylinder 3, creating a high-pressure chamber 32 within the cylinder 3. At this time, the hydraulic tappet body approximates a rigid body, effectively achieving pressure transmission between the cam and the valve lifter or between the rocker arm and the valve lifter. Correspondingly, the area outside the cylinder 3 is a low-pressure chamber, formed between the plunger 2 and the housing 1, while the high-pressure chamber 32 is formed between the plunger 2 and the cylinder 3. The low-pressure chamber is further divided into a first oil reservoir 13 and a second oil reservoir 21. The first oil reservoir 13 is located inside the housing 1, and the second oil reservoir 21 is located inside the plunger 2. The first oil reservoir 13 and the second oil reservoir 21 are connected by an oil passage 12.

[0027] In addition, when the valve pushrod expands slowly due to the increase in operating temperature, the oil in the cylinder 3 can slowly leak from the inner wall of the cylinder 3 and the outer wall of the plunger 2. That is, the hydraulic pushrod body will adaptively generate a certain amount of contraction to adapt to the expansion space of the valve pushrod caused by heat, thus avoiding the air leakage problem caused by the valve not closing tightly.

[0028] Because motorcycles operate under more unique conditions than cars, especially when cornering, they experience greater body roll. This can cause the motorcycle's oil pump to temporarily lose oil, resulting in a pump cavitation and a sudden drop in oil pressure. Consequently, the valve clearance compensation mechanism immediately deflates and softens, failing to effectively compensate for valve clearance, thus generating impact noise and accelerating component wear. Therefore, this invention proposes further improvements.

[0029] Reference Figures 1 to 3The hydraulic tappet body has an accumulator cylinder 5 on its side wall of housing 1. An accumulator chamber 51 is formed inside the accumulator cylinder 5, and the accumulator chamber 51 is connected to the first oil storage chamber 13 of housing 1, allowing low-pressure oil from housing 1 to enter the accumulator chamber 51. An accumulator piston 52 and a preload spring 53 are installed inside the accumulator chamber 51. One end of the accumulator piston 52 is connected to the preload spring 53, and the other end is in contact with the oil in the first oil storage chamber 13. The initial preload of the preload spring 53 is lower than the working pressure of the low-pressure chamber. When the oil pump is operating normally, it stably supplies oil to the interior of the hydraulic tappet body through the oil inlet 11. Because the oil pressure in the low-pressure chamber is greater than the preload of the preload spring 53, the oil pressure pushes the accumulator piston 52 to compress the preload spring 53, gradually filling the volume inside the accumulator chamber 51 with oil, and the accumulator chamber 51 is in a compressed energy storage state. When the oil pump sucks in air, the oil pressure in the low-pressure chamber will drop instantly to below the accumulator pressure of the accumulator piston 52. Therefore, the preload spring 53 will push the oil in the accumulator chamber to the low-pressure chamber and enter the oil cylinder 3 through the one-way valve. This ensures that even if the oil pump sucks in air briefly, there is still a pressurized oil source in the low-pressure chamber to replenish the high-pressure chamber 32, preventing adverse effects caused by the hydraulic tappet body failing to properly compensate for valve clearance.

[0030] Reference Figures 1 to 3 The oil inlet 11 and the accumulator 51 are respectively located at the radial ends of the telescopic body, so that the accumulator 51 is far away from the oil inlet 11. This ensures that when the oil pump sucks in air, the area around the accumulator 51 remains pure oil, preventing air from being instantly introduced due to proximity to the oil inlet 11, which would prevent effective hydraulic transmission. In addition, the oil passage 12 and the accumulator 51 are located at the same radial end of the telescopic body, making the distance between the accumulator 51 and the oil passage 12 closer. This allows the oil in the accumulator 51 to pass through the oil passage 12 more quickly into the plunger 2 and then into the high-pressure chamber 32 when the oil pump releases energy due to sucking in air.

[0031] Reference Figure 2 and Figure 3 The accumulator 51 is equipped with a one-way throttle valve at its port. The one-way throttle valve makes the filling speed of the accumulator 51 lower than the draining speed. On the one hand, when the oil pressure in the low-pressure chamber pushes the accumulator piston 52 to compress the preload spring 53, the oil needs to enter slowly through the throttle orifice 62 of the one-way throttle valve, avoiding the pressure fluctuation in the low-pressure chamber and causing the accumulator piston 52 to move frequently. It also ensures that the oil can be better prioritized to fill the high-pressure chamber 32 between the plunger 2 and the cylinder 3, achieving slow filling. On the other hand, when the oil in the accumulator 51 needs to release energy, it can flow out quickly through the opening of the valve, effectively dealing with the situation of the oil pump sucking in air and achieving rapid energy release.

[0032] Reference Figure 2 and Figure 3The one-way throttle valve includes a one-way valve diaphragm 61 and a throttle orifice 62. The one-way valve diaphragm 61 covers the port of the accumulator 51, closing when oil enters the accumulator 51 and opening when oil drains from the accumulator 51. The throttle orifice 62 is parallel to the port of the accumulator 51 at the same end of the accumulator 51, and the flow rate of the throttle orifice 62 is always less than the flow rate at the port of the accumulator 51 when the one-way valve diaphragm 61 is open. In this embodiment, the one-way valve diaphragm 61 is fixed at the port of the accumulator 51 by two-point fixing, so that the one-way valve diaphragm 61 can open under the oil pressure of the accumulator 51 while ensuring positional stability, ensuring rapid oil flow when the accumulator 51 releases energy. In other embodiments, the one-way valve diaphragm 61 can also be fixed by other methods, and the one-way valve diaphragm 61 can also be replaced by a one-way valve body such as a ball 42, as long as the one-way throttling effect can be achieved.

[0033] Reference Figure 1 and Figure 2 The accumulator cylinder 5 is detachably mounted on the side wall of the housing 1. Specifically, the port of the accumulator cylinder 5 is provided with external threads, and the side wall of the housing 1 is provided with internal threads. The accumulator cylinder 5 and the housing 1 are connected by threads, and a gasket 9 is provided between the accumulator cylinder 5 and the housing 1 to reduce oil leakage at the connection between the accumulator cylinder 5 and the housing 1.

[0034] Reference Figures 1 to 3 An adjusting piston 7 is installed inside the accumulator chamber 51. A preload spring 53 is connected between the adjusting piston 7 and the accumulator piston 52. In this embodiment, the accumulator chamber 51 is a rectangular chamber, and correspondingly, the adjusting piston 7 and the accumulator piston 52 are also rectangular pistons. An adjusting screw 71 is rotatably connected to the end of the adjusting piston 7 facing away from the accumulator spring. The adjusting screw 71 is further threadedly connected to the outer end of the accumulator cylinder 5. Through the above structure, the position of the adjusting piston 7 is adjustable and remains fixed after adjustment, thereby making the preload of the preload spring 53 adjustable. When the adjusting screw 71 is screwed inward, the preload spring 53 is further compressed, thereby increasing the preload. This is suitable for engines with higher oil pressure, preventing frequent operation under normal oil pressure. When the adjusting screw 71 is screwed outward, the length of the preload spring 53 is released, thereby reducing the preload. This is suitable for engines with lower oil pressure, ensuring that they can be filled with oil under normal oil pressure. Ultimately, by making the preload of the preload spring 53 adjustable, the accumulator cylinder 5 can be flexibly applied to various engine models, significantly improving the versatility of parts. Furthermore, with prolonged use of the hydraulic tappet body, the preload spring 53 may experience a decline in elasticity. This decline can be compensated by resetting the position of the adjusting piston 7 during engine maintenance, thereby resetting the preload.

[0035] Reference Figure 2 and Figure 3The accumulator 5 has a split structure, wherein the outer end of the accumulator 5 is detachably provided with a cover, and the adjusting screw 71 of the adjusting piston 7 is threadedly connected to the cover. The split structure of the accumulator 5 and the fact that the accumulator 5 can be detached from the housing 1 make the assembly and installation of the accumulator 5 more convenient.

[0036] Reference Figures 1 to 3 An adjusting rod 621 is radially movable on the inner wall of the throttle orifice 62. The adjusting rod 621 is used to control the minimum passage cross-section of the throttle orifice 62. When the adjusting rod 621 extends outward, it reduces the minimum passage cross-section of the throttle orifice 62, thus reducing the oil filling efficiency. When the adjusting rod 621 retracts inward, it increases the minimum passage cross-section of the throttle orifice 62, thus increasing the oil filling efficiency. Too low or too high oil filling efficiency of the accumulator 51 will cause different negative effects. When the oil filling efficiency of the accumulator 51 is too low, it will prevent the accumulator 51 from completing energy storage in time, thus failing to respond promptly to the oil pump sucking in air. When the oil filling efficiency of the accumulator 51 is too high, it will reduce the priority of oil filling into the high-pressure chamber 32 between the plunger 2 and the cylinder 3, causing the hydraulic tappet body to fail to eliminate valve clearance in time. The setting of the adjusting rod 621 of the throttle orifice 62 can better maintain a reasonable oil filling efficiency according to the setting of the accumulator 51 and the oil pressure. For example, when the working pressure of the low-pressure chamber is relatively high, the preload of the preload spring 53 is also increased accordingly. At this time, the higher oil pressure and the smaller space of the accumulator chamber 51 will cause the accumulator chamber 51 to fill with oil more quickly. Therefore, the minimum cross-section of the throttle orifice 62 can be reduced to improve the priority of oil replenishment in the high-pressure chamber 32 while ensuring the oil filling efficiency. When the working pressure of the low-pressure chamber is relatively low, the preload of the preload spring 53 is also reduced accordingly. At this time, the lower oil pressure and the larger space of the accumulator chamber 51 will cause the accumulator chamber 51 to fill with oil more slowly. Therefore, the minimum cross-section of the throttle orifice 62 can be increased to avoid the situation where the oil pump cannot handle the situation of the accumulator chamber 51 sucking in air due to the low oil filling efficiency. This achieves the effect of balancing the oil filling efficiency of the accumulator chamber 51 and the priority of oil replenishment in the high-pressure chamber 32.

[0037] Reference Figures 1 to 3A control assembly connects the adjusting rod 621 and the adjusting piston 7. The control assembly causes the adjusting rod 621 to increase the minimum cross-section of the throttle orifice 62 as the adjusting piston 7 retracts, and to decrease the minimum cross-section of the throttle orifice 62 as the adjusting piston 7 advances. The retraction of the adjusting piston 7 releases the length of the preload spring 53, and the forward movement of the adjusting piston 7 compresses the length of the preload spring 53. Specifically, the control assembly includes a hydraulic line 8 located inside the cylinder wall of the accumulator cylinder 5. A front control piston 81 and a rear control piston 82 are installed within the hydraulic line 8. The front control piston 81 is farther from the adjusting rod 621 than the rear control piston 82. A connecting rod 72 connects the front control piston 81 to the adjusting piston 7, while the rear control piston 82 is connected to the adjusting rod 621. When the adjusting piston 7 retracts, it drives the front control piston 81 to retract synchronously, thereby releasing the hydraulic line 8. The adjusting rod 621 of the throttle orifice 62 retracts under the control of the rear control piston 82, thereby increasing the minimum passage cross section of the throttle orifice 62. When the adjusting piston 7 moves forward, it drives the front control piston 81 to move forward synchronously, thereby squeezing the hydraulic line 8. The adjusting rod 621 of the throttle orifice 62 extends under the control of the rear control piston 82, thereby reducing the minimum passage cross section of the throttle orifice 62. Ultimately, the position of the adjusting rod 621 is adaptively adjusted according to the position of the adjusting piston 7. When the preload of the preload spring 53 is set, there is no need to adjust the position of the adjusting rod 621 again to ensure that the oil filling efficiency of the accumulator 51 is kept at a reasonable value.

[0038] Reference Figure 2 and Figure 3 The connecting rod 72 can be entirely disposed within the accumulator chamber 51 or partially disposed outside the accumulator chamber 51. In this embodiment, the connecting rod 72 is partially disposed outside the accumulator chamber 51, and the connecting rod 72 has a three-section split structure to facilitate assembly. In addition, the outer end and side wall of the accumulator cylinder 5 are respectively provided with installation inlets for inserting the front control piston 81 and the rear control piston 82, so as to facilitate the installation of the front control piston 81 and the rear control piston 82 during the assembly stage.

[0039] Reference Figure 3 The hydraulic pipeline 8 is divided into a front pipeline and a rear pipeline. The front control piston 81 is located in the front pipeline, and the rear control piston 82 is located in the rear pipeline. The cross-section of the front pipeline is smaller than that of the rear pipeline. Through the difference in the cross-sections of the front and rear pipelines, on the one hand, the adjusting piston 7 has an assisting effect in the control process of driving the adjusting rod 621, making the adjusting rod 621 easier to follow. On the other hand, the extension and retraction of the adjusting rod 621 is less than the actual displacement of the adjusting piston 7, thereby allowing the adjusting rod 621 to be adjusted within a smaller range.

[0040] Reference Figure 3The side wall of the hydraulic line 8 extends through a channel to the outside of the accumulator cylinder 5. This channel is used to inject the medium into the hydraulic line 8 and is equipped with an oil seal.

[0041] Reference Figures 1 to 3 As the output power of the internal combustion engine increases, the operating temperature of the valve train will rise. In addition to causing the valve pushrod to expand to a certain extent, this will also cause two changes to the working process of the hydraulic tappet body. The first change is that the number of extensions and retractions of the hydraulic tappet per unit time will increase with the output power of the internal combustion engine. The second change is that the extension and retraction amount of the hydraulic tappet in each extension and retraction process will decrease, that is, the volume of the high-pressure chamber 32 will decrease to accommodate the expansion of the valve pushrod. To enable the accumulator chamber 51 to cope with changes in the output power of the internal combustion engine, a gasket 9 is provided on the side of the adjusting piston 7 facing the accumulator piston 52. The gasket 9 is a high expansion coefficient gasket 9. As the temperature increases, the gasket 9 will expand, which will reduce the available accumulator space of the accumulator chamber 51. Since the volume of the high-pressure chamber 32 has also shrunk at this time, even if the oil pump sucks in air, the accumulator chamber 51 can still replenish enough oil into the low-pressure chamber and the high-pressure chamber 32 in sequence. However, the expansion of the gasket 9 will not change the minimum throttling cross section of the throttle orifice 62. This allows the accumulator chamber 51 to reach the full state more quickly, so that the low-pressure chamber ends the state of charging and supplying more quickly, and enters the state of concentrated supply to the high-pressure chamber 32 between the plunger 2 and the cylinder 3, in order to cope with the improvement of the operating efficiency of the valve train. In this embodiment, the gasket 9 is preferably an ACM oil-resistant rubber gasket 9, which is more suitable for use in the oil environment and is more prone to thermal expansion than metal.

[0042] This embodiment also discloses an engine that employs the aforementioned valve clearance compensation mechanism.

[0043] In summary, the valve clearance compensation mechanism of this invention and the engine utilize the accumulator piston and preload spring in the accumulator chamber to slowly accumulate pressure during normal operation. When the oil pump sucks in cavitation, the oil pressure in the low-pressure chamber will instantly drop below the accumulator piston's pressure. Therefore, the preload spring will push the oil in the accumulator chamber to the low-pressure chamber and enter the high-pressure chamber of the oil cylinder through the one-way valve. This ensures that even if the oil pump sucks in cavitation briefly, there is still a pressurized oil source in the low-pressure chamber to replenish the high-pressure chamber, preventing adverse effects caused by the hydraulic tappet body failing to properly compensate for valve clearance.

[0044] The above are all preferred embodiments of the present invention and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. A valve clearance compensation mechanism, comprising a hydraulic tappet body, the hydraulic tappet body including a low-pressure chamber and a high-pressure chamber (32) for storing engine oil, characterized in that, The side wall of the hydraulic tappet body is provided with an accumulator cylinder (5), and an accumulator chamber (51) is formed inside the accumulator cylinder (5). The accumulator chamber (51) is connected to the low-pressure chamber. An accumulator piston (52) and a preload spring (53) are provided inside the accumulator chamber (51). One end of the accumulator piston (52) is connected to the preload spring (53), and the other end is in contact with the oil in the low-pressure chamber.

2. The valve clearance compensation mechanism according to claim 1, characterized in that: The hydraulic tappet body includes a housing (1) and a telescopic body arranged along the central axis inside the housing (1). The telescopic body includes a plunger (2) and a cylinder (3) that are telescopically connected. The top of the plunger (2) abuts against the top surface of the housing (1). The bottom of the plunger (2) is connected to the cylinder (3) by a first spring (31). The plunger (2) is also provided with a one-way valve. The oil in the low-pressure chamber enters the high-pressure chamber (32) through the one-way valve. The oil in the high-pressure chamber (32) returns to the low-pressure chamber through the gap between the plunger (2) and the cylinder (3). The low-pressure chamber is formed between the plunger (2) and the housing (1). The high-pressure chamber (32) is formed between the plunger (2) and the cylinder (3).

3. The valve clearance compensation mechanism according to claim 1, characterized in that: The accumulator (51) is equipped with a one-way throttle valve at its port, which makes the oil filling speed of the accumulator (51) lower than the oil draining speed.

4. A valve clearance compensation mechanism according to claim 3, characterized in that: The one-way throttle valve includes a one-way valve diaphragm (61) and a throttle orifice (62). The one-way valve diaphragm (61) covers the port of the accumulator (51). The one-way valve diaphragm (61) is closed when oil enters the accumulator (51) and is opened when oil drains from the accumulator (51). The throttle orifice (62) is opened parallel to the port of the accumulator (51) at the same end of the accumulator (51).

5. A valve clearance compensation mechanism according to claim 4, characterized in that: An adjusting piston (7) is provided in the accumulator (51). The preload spring (53) is connected between the adjusting piston (7) and the accumulator piston (52). The adjusting piston (7) is rotatably connected to an adjusting screw (71). The adjusting screw (71) is threadedly connected to the end of the accumulator cylinder (5).

6. A valve clearance compensation mechanism according to claim 5, characterized in that: The throttling orifice (62) is radially movably provided with an adjusting rod (621). The adjusting rod (621) is used to control the minimum passing cross section of the throttling orifice (62). A control component is connected between the adjusting rod (621) and the adjusting piston (7). The adjusting rod (621) increases the minimum passing cross section of the throttling orifice (62) as the adjusting piston (7) moves backward, and decreases the minimum passing cross section of the throttling orifice (62) as the adjusting piston (7) moves forward.

7. A valve clearance compensation mechanism according to claim 6, characterized in that: The control assembly includes a hydraulic line (8) formed inside the cylinder wall of the accumulator (5). The hydraulic line (8) is provided with a front control piston (81) and a rear control piston (82). The front control piston (81) is farther away from the adjusting rod (621) than the rear control piston (82). A connecting rod (72) connects the front control piston (81) and the adjusting piston (7). The rear control piston (82) is connected to the adjusting rod (621). The front control piston (81) releases the hydraulic line (8) as the adjusting piston (7) moves backward. The front control piston (81) squeezes the hydraulic line (8) as the adjusting piston (7) moves forward.

8. A valve clearance compensation mechanism according to claim 7, characterized in that: The hydraulic pipeline (8) is divided into a front pipeline and a rear pipeline. The front control piston (81) is located in the front pipeline, and the rear control piston (82) is located in the rear pipeline. The cross-section of the front pipeline is smaller than that of the rear pipeline.

9. A valve clearance compensation mechanism according to claim 6, characterized in that: The adjusting piston (7) is provided with a gasket (9) on the side facing the accumulator piston (52), and the gasket (9) is a high expansion coefficient gasket (9).

10. An engine, characterized in that: The valve clearance compensation mechanism as described in any one of claims 1-9 is adopted.

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