Device and method for reducing engine starting torque

Abstract

A device and method for reducing engine starting torque includes a housing, a piston mechanism and a starting mechanism disposed within the housing. The driving piston of the piston mechanism includes a non-working end and a working end. When fluid from a fluid passage within the housing acts on the non-working end of the driving piston, the driving piston is placed in a non-operating position, placing the starting mechanism in a non-starting state and separating it from the engine's valve bridge or valve, with the valve in a normal operating state. When fluid from the fluid passage within the housing acts on the working end of the driving piston, the driving piston is placed in an operating position, placing the starting mechanism in a starting state, preventing the opened valve from returning to its seat and remaining open. The present invention utilizes oil pressure at both ends of the driving piston to control a fixed-chain starting mechanism, allowing the valve to remain slightly open during engine shutdown, stop, and start-up, thereby improving the engine's shutdown and starting performance, while not interfering with valve movement during engine ignition and operation.

Description

Technical Field

[0001] The present invention relates to the field of machinery, in particular to vehicle engine technology, and more particularly to a device and method for reducing engine starting torque. Background Art

[0002] The performance of an engine includes conventional ignition performance and other auxiliary performance, such as engine braking performance, engine shutdown and starting performance, etc. Although there have been great improvements in the hardware and software of the engine, such as the use of new technologies such as heating during cold start, compression ignition diesel engines are still difficult to start in cold weather. Large commercial vehicle engines also have defects such as unstable operation, vibration and noise during shutdown. The auxiliary valve drive mechanisms currently used to improve engine performance are mostly hydraulic mechanisms. After the engine is turned off, the hydraulic mechanism cannot keep the engine valves open. Leakage of fluid (such as engine oil) will cause the hydraulic mechanism to fail, because the hydraulic mechanism cannot be supplied with oil after the engine is shut down, and the lost fluid cannot be replenished, thereby losing the hydraulic connection. The engine valve opened by the fluid will fall closed under the action of the valve spring. Summary of the Invention

[0003] The object of the present invention is to provide a device and method for reducing the starting torque of an engine. The device for reducing the starting torque of an engine is to solve the technical problems in the prior art of large vibration and noise during parking and difficulty in cold starting the engine, as well as the technical problem that the hydraulic mechanism cannot keep the engine valve open after the engine is turned off.

[0004] The device for reducing the starting torque of an engine of the present invention comprises a housing and a piston mechanism and a starting mechanism arranged in the housing. The piston mechanism comprises a driving piston arranged in a driving piston hole of the housing. A fluid channel is also provided in the housing, and is characterized in that: the driving piston comprises a non-working end and a working end. When the fluid from the fluid channel acts on the non-working end of the driving piston, the driving piston is placed in a non-operating position in the driving piston hole, and the driving piston places the starting mechanism in a non-starting state. The starting mechanism is separated from the valve bridge or valve of the engine, and the valve is in a normal operating state. When the fluid from the fluid channel acts on the working end of the driving piston, the driving piston is placed in an operating position in the driving piston hole, and the driving piston places the starting mechanism in a starting state, so that the opened valve cannot return to its seat and remains open.

[0005] Furthermore, the fluid includes engine oil.

[0006] Furthermore, the fluid channel in the box body includes a lubricating oil channel and a starting oil channel, the lubricating oil channel leads to the driving piston hole on the non-working end side of the driving piston, and the starting oil channel leads to the driving piston hole on the working end side of the driving piston.

[0007] Furthermore, the non-working end and the working end of the driving piston include two ends of different sizes.

[0008] Furthermore, the outer diameter of the working end of the driving piston is larger than the outer diameter of the non-working end.

[0009] Furthermore, the piston mechanism also includes a positioning spring, which is located on the working end side of the drive piston. The positioning spring biases the drive piston to an operating position in the drive piston hole.

[0010] Furthermore, the force of the positioning spring is the product of the oil pressure when the engine is started and the pressure area of ​​the non-working end of the driving piston.

[0011] Furthermore, the device for reducing the engine starting torque also includes an oil unloading mechanism, which includes an oil unloading piston and a return spring arranged in the oil unloading piston hole of the casing, and an oil supply groove and an oil unloading channel are provided on the oil unloading piston. The oil unloading piston includes an oil supply position and an oil unloading position, and both ends of the oil unloading piston bear the force of the return spring and the pressure of the engine oil respectively. The return spring places the oil unloading piston in the oil supply position, and the engine oil enters the driving piston hole from the non-working end side of the driving piston through the lubricating oil channel and the oil supply groove on the oil unloading piston, and the driving piston is placed in the non-operating position; the engine oil from the starting oil channel acts on the oil unloading piston from the end without the return spring, compressing the return spring to place the oil unloading piston in the oil unloading position, connecting the oil unloading channel and the driving piston hole on the non-working end side of the driving piston to unload the oil, and the driving piston moves to the operating position.

[0012] Furthermore, the starting mechanism includes a swinging mechanism, which includes a swinging member installed on a swinging shaft, which is installed on a box body, and the swinging member includes a connecting end and a working end, the connecting end of the swinging member is connected to a driving piston, and the driving piston drives the swinging member to swing between a non-starting state and a starting state. In the non-starting state, the working end of the swinging member is separated from the valve bridge or valve; in the starting state, the working end of the swinging member acts on the valve bridge or valve.

[0013] Furthermore, the housing includes a rocker arm of the engine.

[0014] The present invention also provides a method for reducing engine starting torque, comprising a process of using a starting device to push open an engine valve, the starting device comprising a housing, a piston mechanism disposed within the housing, and a starting mechanism, the piston mechanism comprising a driving piston disposed within a driving piston hole within the housing, the driving piston comprising a non-working end and a working end, and a fluid passage being further disposed within the housing. The method is characterized in that the method comprises the following steps:

[0015] 1. When the engine is turned off, the fluid is delivered to the driving piston hole on the working end side of the driving piston through the fluid channel in the box.

[0016] 2. The driving piston moves to the operating position and pushes the starting mechanism to the starting state.

[0017] 3. The engine's valve drive mechanism opens the engine's valves,

[0018] 4. The starting mechanism reaches the starting state and acts on the return valve bridge or valve, so that the opened valve cannot return to its seat and remains open.

[0019] 5. When the engine is stopped, the starting mechanism is still in the starting state and the valve remains open.

[0020] 6. When the engine starts, the starting mechanism keeps the valve open to reduce the torque of the engine start.

[0021] 7. The fluid enters the driving piston hole on the non-working end side of the driving piston through the fluid channel in the box, and the driving piston moves to the non-operating position, pushing the starting mechanism to the non-starting state, separating from the valve bridge or valve, and the valve returns to its seat and closes.

[0022] 8. When the engine is ignited, the fluid pressure acting on the non-working end keeps the driving piston in the non-operating position, and the starting mechanism remains in the non-starting state, separated from the valve bridge or valve.

[0023] Furthermore, the invention further includes an oil unloading mechanism, the oil unloading mechanism including an oil unloading piston and a return spring disposed in an oil unloading piston hole of the casing, the oil unloading piston having an oil supply groove and an oil unloading channel, the oil unloading piston moving between an oil supply position and an oil unloading position in the oil unloading piston hole, and the method for reducing the engine starting torque includes the following steps:

[0024] 1. When the engine is turned off, the fluid is delivered to the oil unloading piston hole and the driving piston hole on the working end side of the driving piston through the fluid channel in the box.

[0025] 2. The fluid pressure overcomes the force of the return spring, pushing the oil unloading piston from the oil supply position to the oil unloading position, connecting the oil unloading channel of the oil unloading piston and the driving piston hole on the non-working end side of the driving piston to drain the fluid.

[0026] 3. The driving piston moves to the operating position and pushes the starting mechanism to the starting state.

[0027] 4. The engine's valve drive mechanism opens the engine's valves,

[0028] 5. The starting mechanism reaches the starting state and acts on the return valve bridge or valve, so that the opened valve cannot return to its seat and remains open.

[0029] 6. When the engine is stopped, the starting mechanism is still in the starting state and the valve remains open.

[0030] 7. The oil unloading piston returns to the oil supply position from the oil unloading position under the action of the return spring.

[0031] 8. When the engine starts, the starting mechanism keeps the valve open to reduce the torque of the engine start.

[0032] 9. The fluid is input into the driving piston hole on the non-working end side of the driving piston through the fluid channel in the box and the oil supply groove on the oil unloading piston. The driving piston moves to the non-operating position, pushing the starting mechanism to the non-starting state, separating from the valve bridge or valve, and the valve returns to its seat and closes.

[0033] 10. When the engine is ignited, the fluid pressure acting on the non-working end keeps the driving piston in the non-operating position, and the starting mechanism remains in the non-starting state, separated from the valve bridge or valve.

[0034] Compared to existing technologies, the present invention offers significant and effective results. The present invention controls the starting mechanism by driving oil pressure at both ends of the piston, keeping the valves slightly open during engine shutdown, stop, and start-up, improving engine stopping and starting performance while not interfering with valve movement during engine ignition and operation. Because the starting mechanism of the present invention is a solid-chain load-bearing mechanism, even when the oil pressure reaches zero after engine shutdown, the engine valves remain open during startup, thereby reducing torque during engine startup. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 It is a general schematic diagram of a first embodiment of a device for reducing engine starting torque of the present invention in a non-starting state.

[0036] Figure 2 The figure is a general schematic diagram of a first embodiment of a device for reducing engine starting torque according to the present invention in a starting state.

[0037] Figure 3 It is a schematic diagram of a partially enlarged mechanism in a second embodiment of a device for reducing engine starting torque according to the present invention.

[0038] Figure 4 It is a top sectional view of the oil unloading mechanism in the oil supply position in the third embodiment of the device for reducing engine starting torque of the present invention.

[0039] Figure 5 It is a top cross-sectional view of the oil unloading mechanism in the oil unloading position in the third embodiment of the device for reducing engine starting torque of the present invention. DETAILED DESCRIPTION

[0040] Embodiment 1:

[0041] like Figure 1 and Figure 2 As shown, the device 100 for reducing the starting torque of an engine in this embodiment includes a housing (here, the rocker arm of the engine) 210, a piston mechanism 20 and a starting mechanism 10 disposed in the rocker arm 210. The driving piston 22 of the piston mechanism 20 is disposed in the driving piston hole 190 of the rocker arm 210. The driving piston 22 has a non-working end (left end) 21 and a working end (right end) 29. The piston mechanism 20 also includes a positioning spring 28. The positioning spring 28 is located on the side of the working end 29 of the driving piston 22. The positioning spring 28 biases the driving piston 22 in the driving piston hole 190 to an operating position ( Figure 2 ), corresponding to the starting state of the starting mechanism 10. The other end (right end) of the positioning spring 28 has a sealing screw plug 164, which makes the driving piston hole 190 a closed hole ( Figure 1 and Figure 2 ).

[0042] The starting mechanism 10 is located on the valve bridge 400 of the engine (it can also be located on the valve 301 of the engine, such as when there is no valve bridge or other special circumstances). The starting mechanism 10 here is a swing mechanism, which is a non-hydraulic solid chain type load-bearing mechanism. The swing mechanism 10 includes a swing member 12 mounted on a swing shaft 14, and the swing shaft 14 is mounted on the rocker arm 210. The swing mechanism 10 has a connecting end and a working end. The end surface 11 of the working end can be designed as a cylindrical surface, which acts on the valve bridge 400 or the valve 301 ( Figure 2 ); the ball pin 16 at the connecting end is connected to the annular groove 23 on the drive piston 22, and the drive piston 22 drives the swing member 12 in the non-starting state ( Figure 1 ) and startup status ( Figure 2 ) swings between.

[0043] The rocker arm 210 is also provided with fluid passages 113 and 213, which respectively deliver fluid (including engine oil, also called lubricating oil) to the drive piston holes 190 at both ends of the drive piston 22 (working end 29 and non-working end 21). Therefore, the fluid passages 113 and 213 are also called the starting oil passage and the lubricating oil passage, respectively. During engine operation, the engine oil continuously flows through the lubricating oil passage 213 to the drive piston hole 190 on the non-working end 21 side of the drive piston 22, causing the drive piston 22 to move to the non-operating position (right), thereby placing the starting mechanism 10 in the non-starting state ( Figure 1 When the engine is turned off (before shutdown), a two-position three-way solenoid valve (not shown) can be opened to supply oil from the starting oil passage 113 to the driving piston hole 190 on the side of the working end 29 of the driving piston 22, so that the driving piston 22 moves to the operating position (left), and the starting mechanism 10 is placed in the starting state ( Figure 2After the engine is shut down, the two-position, three-way solenoid valve is closed to drain oil, and the oil pressure in fluid passages 113 and 213 is zero. Drive piston 22 remains in the operating position due to the bias of detent spring 28, and starting mechanism 10 is in the activated state. The solid-body rocker 12 acts on valve bridge 400 and valve 301, keeping valve 301 slightly open. The force required by detent spring 28 is very small, roughly the product of the oil pressure at engine startup and the pressure area of ​​the non-operating end 21 of drive piston 22.

[0044] Rocker arm 210 is a component of the engine valve train (or drive train), and is equipped with a valve lash adjustment system 50, including an anti-blowout spring 198. The engine valve system 300, located below the valve bridge 400, includes two valves 301 and 302, which are biased against valve seats 320 in the engine block 500 by valve springs 310 and 312, preventing gas from flowing between the engine cylinders and the exhaust pipe 600. Rocker arm 210 is driven by the engine's cam (not shown), acting on the valve bridge 400 and valves 301 and 302 through the valve lash adjustment system 50, causing them to open and close cyclically.

[0045] The method for reducing the engine starting torque of this embodiment includes a process of using the device for reducing the engine starting torque (starting device) 100 to push open the engine valve 301, and includes the following steps:

[0046] 1. When the engine is turned off (before the engine is shut down), fluid (engine oil) is delivered to the drive piston hole 190 on the right side of the working end 29 of the drive piston 22 through the fluid channel (starting oil channel) 113 in the housing (rocker arm) 210.

[0047] 2. The driving piston 22 moves to the operating position (to the left), pushing the starting mechanism (swing mechanism) 10 to the starting state (from Figures 1 to 2 conversion, the pendulum 12 from tilted to vertical),

[0048] 3. The engine's valve drive mechanism (including the engine's cam (not shown) and rocker arm 210, and a two-valve engine also includes a valve bridge 400) opens the engine's valves 301 and 302.

[0049] 4. The starting mechanism 10 reaches the starting state (swinging member vertical), acting on the return valve bridge 400 or valve 301, so that the opened valve 301 cannot return to its seat and remains open, with an opening of 330 ( Figure 2 ),

[0050] 5. The engine is stopped, the starting mechanism 10 is still in the starting state (the swing member is vertical), and the valve 301 remains open ( Figure 2 ),

[0051] 6. The engine starts, and the starting mechanism 10 keeps the valve 301 open to reduce the torque of the engine start.

[0052] 7. The fluid (engine oil) enters the drive piston hole 190 on the non-working end 21 side (left side) of the drive piston 22 through the fluid channel (lubricating oil channel) 213 in the housing (rocker arm) 210, and the drive piston 22 moves to the non-operating position (to the right), pushing the starting mechanism (swinging mechanism) 10 to the non-starting state (swinging member tilts), separating from the valve bridge 400 or the valve 301, and the valve 301 returns to its seat and closes (from Figure 2 to Figure 1 conversion), and

[0053] 8. The engine is ignited, and the fluid (oil) pressure acting on the non-working end 21 keeps the driving piston 22 in the non-operating position, and the starting mechanism 10 remains in the non-starting state (the swing member is tilted), separated from the valve bridge 400 or the valve 301 ( Figure 1 ).

[0054] Example 2:

[0055] like Figure 3 As shown, the driving piston 22 of the piston mechanism 20 of the starting device 100 of this embodiment has two ends of different sizes. The pressure-bearing area of ​​the working end 29 (the cross-sectional area of ​​the cylindrical surface 27) is larger than the pressure-bearing area of ​​the non-working end 21 (the cross-sectional area of ​​the cylindrical surface 26). When the two ends are subjected to the same fluid (engine oil) pressure, the driving piston 22 of this embodiment with different sizes at both ends generates different forces at the two ends, causing it to lose oil pressure balance and deviate in one direction. Here, the driving piston 22 is shown to move to the operating position (to the left) when the two ends are subjected to the same oil pressure. The starting mechanism 10 moves from the tilted non-starting position ( Figure 1 ) swings to the vertical starting position ( Figure 2 ), because the working end 29 is larger than the non-working end 21.

[0056] Obviously, the driving piston hole 190 in the housing (rocker arm) 210 must be changed to a stepped piston hole with cylindrical surfaces of different sizes to match the driving piston 22 with two end surfaces of different sizes. The working principle and method of this embodiment are the same as those of the previous embodiment.

[0057] Example 3:

[0058] like Figure 4 and Figure 5As shown, the device 100 for reducing the engine starting torque in this embodiment also includes an oil unloading mechanism 30. The oil unloading mechanism 30 includes an oil unloading piston 352 and a return spring 358 arranged in the oil unloading piston hole 360 ​​of the housing (rocker arm) 210. One end of the oil unloading piston hole 360 ​​(the lower end, on the side of the return spring 358) is connected to the outside (not closed). The oil unloading piston 352 has an oil supply groove 356 and an oil unloading channel 354 (including an annular groove, a radial hole and an axial hole). The oil unloading piston 352 moves between an oil supply position (up) and an oil unloading position (down) in the oil unloading piston hole 360.

[0059] When the engine is turned off (before shutdown), a two-position three-way solenoid valve (not shown) can be opened to supply oil from the starting oil passage 113 to the oil unloading piston hole 360 ​​and the driving piston hole 190 on the side of the working end 29 of the driving piston 22 at the same time, so that the driving piston 22 moves to the operating position (left) ( Figure 2 and Figure 5 ), put the starting mechanism 10 into the starting state ( Figure 2 After the engine is shut down, the two-position three-way solenoid valve is closed to drain oil, and the oil pressure in the starting oil passage 113 and the lubricating oil passage 213 is zero. The driving piston 22 is still in the operating position due to the bias of the positioning spring 28, and the starting mechanism 10 is in the starting state. The solid-supported rocker arm 12 keeps the valve 301 slightly open.

[0060] After adding the oil unloading mechanism 30, similar to the first embodiment, the method of reducing the engine starting torque in this embodiment can be divided into the following steps:

[0061] 1. When the engine is turned off (before the engine is shut down), fluid (engine oil) is delivered simultaneously to the unloading piston hole 360 ​​and the drive piston hole 190 on the working end 29 side (right side) of the drive piston 22 through the fluid channel (starting oil channel) 113 in the housing (rocker arm) 210.

[0062] 2. The fluid (oil) pressure overcomes the force of the return spring 358, moving the oil unloading piston 352 from the oil supply position ( Figure 4 ) to the oil unloading position ( Figure 5 ), the oil discharge passage 354 of the oil discharge piston 352 is connected to discharge the fluid (engine oil) from the driving piston hole 190 on the side (left side) of the non-working end 21 of the driving piston 22,

[0063] 3. Drive piston 22 to the operating position ( Figure 2 and Figure 5 ), push the starting mechanism (swing mechanism) 10 to the starting state ( Figure 2 ),

[0064] 4. The engine's valve drive mechanism opens the engine's valves 301 and 302,

[0065] 5. The starting mechanism 10 reaches the starting state ( Figure 2 ), acting on the return valve bridge 400 or the valve 301, so that the opened valve 301 cannot return to its seat and remains open.

[0066] 6. The engine is stopped, the starting mechanism 10 is still in the starting state, and the valve 301 remains open ( Figure 2 ),

[0067] 7. The oil unloading piston 352 moves from the oil unloading position ( Figure 5 ) Return to the oil supply position ( Figure 4 ),

[0068] 8. The engine starts, and the starting mechanism 10 keeps the valve 301 open ( Figure 2 ) and reduce the engine starting torque,

[0069] 9. The fluid (engine oil) is fed into the drive piston hole 190 on the non-working end 21 side of the drive piston 22 through the fluid passage (lubricating oil passage) 213 in the housing (rocker arm) 210 and the oil supply groove 356 on the oil unloading piston 352, and the drive piston 22 moves to the non-operating position ( Figure 1 and Figure 5 ), push the starting mechanism 10 to the non-starting state, separate from the valve bridge 400 or the valve 301, and the valve 301 returns to its seat and closes ( Figure 1 ),and

[0070] 10. The engine is ignited, and the fluid (oil) pressure acting on the non-working end 21 keeps the driving piston 22 in the non-operating position, and the starting mechanism remains in the non-starting state, separated from the valve bridge or valve ( Figure 1 ).

[0071] The above description includes a few specific embodiments, which should not be considered as limiting the scope of the present invention. Instead, they serve as specific examples of the present invention, from which many other variations are possible. For example, the device for reducing engine starting torque shown here can be used not only in pushrod engines but also in overhead cam engines; can be used to actuate not only exhaust valves but also intake valves; can be used for not only one valve but also two or more valves, and can also have different valve openings.

[0072] In addition, the number of cylinders whose engine valves are kept open by the starting mechanism can be selected as needed. Sometimes it is not necessary to keep all cylinders open, but only keep the engine valves of some cylinders open by the starting mechanism, and the engine valves of the remaining cylinders remain in the original starting state and are not affected by the starting mechanism.

[0073] Furthermore, the control for transitioning the pistons (both the drive and drain pistons) between their positions can be varied, not limited to the engine oil or two-position, three-way solenoid valves. The orientation and mounting method of the pistons within the rocker arms can also vary. The associated spring forces and fluid (oil) pressures can be adjusted as needed.

[0074] Therefore, the scope of the invention should be determined not by the specific examples described above, but rather by the appended claims and their legal equivalents.

Claims

1. A device for reducing engine starting torque, comprising a housing, a piston mechanism disposed within the housing, and a starting mechanism, wherein the housing includes a rocker arm of the engine, the piston mechanism includes a drive piston disposed within a drive piston hole within the housing, and a fluid passage is further disposed within the housing, characterized in that: The driving piston includes a non-working end and a working end. When the fluid from the fluid channel acts on the non-working end of the driving piston, the driving piston is placed in a non-operating position in the driving piston hole, and the driving piston places the starting mechanism in a non-starting state. The starting mechanism is separated from the valve bridge or valve of the engine, and the valve is in a normal operating state. When the fluid from the fluid channel acts on the working end of the driving piston, the driving piston is placed in an operating position in the driving piston hole, and the driving piston places the starting mechanism in an started state, so that the opened valve cannot return to its seat and remains open. The fluid channel includes a lubricating oil channel and a starting oil channel. The lubricating oil channel leads to the driving piston hole on the non-working end side of the driving piston, and the starting oil channel leads to the driving piston hole on the working end side of the driving piston. and a control button to control the oil pump, so that the oil pump can be turned on and off, and the control button can be turned on to check the oil pumping effect of the oil pump.

2. The device for reducing engine starting torque according to claim 1, characterized in that: The fluid includes engine oil.

3. The device for reducing engine starting torque according to claim 1, wherein: The non-working end and the working end of the driving piston include two ends of different sizes.

4. The device for reducing engine starting torque according to claim 3, characterized in that: The outer diameter of the working end of the driving piston is larger than the outer diameter of the non-working end.

5. The device for reducing engine starting torque according to claim 1, characterized in that: The piston mechanism further comprises a positioning spring, which is located on one side of the working end of the driving piston. The positioning spring biases the driving piston in the driving piston hole to an operating position.

6. The device for reducing engine starting torque according to claim 5, characterized in that: The force of the positioning spring is the product of the oil pressure when the engine is started and the pressure area of ​​the non-working end of the driving piston.

7. The device for reducing engine starting torque according to claim 1, wherein: The starting mechanism includes a swinging mechanism, which includes a swinging member installed on a swinging shaft, which is installed on a box body. The swinging member includes a connecting end and a working end. The connecting end of the swinging member is connected to a driving piston, which drives the swinging member to swing between a non-starting state and a starting state. In the non-starting state, the working end of the swinging member is separated from the valve bridge or valve; in the starting state, the working end of the swinging member acts on the valve bridge or valve.

8. A method for reducing engine starting torque, comprising a process of using a starting device to push open an engine valve, the starting device comprising a housing, a piston mechanism disposed within the housing, and a starting mechanism, the piston mechanism comprising a driving piston disposed within a driving piston hole within the housing, the driving piston comprising a non-working end and a working end, the housing further comprising a fluid passage, the starting device further comprising an oil unloading mechanism comprising an oil unloading piston disposed within the oil unloading piston hole within the housing and a return spring, the oil unloading piston having an oil supply groove and an oil unloading passage thereon, the oil unloading piston moving between an oil supply position and an oil unloading position within the oil unloading piston hole, the method being characterized in that: The method comprises the following steps: 1) When the engine is turned off, fluid is delivered to the driving piston and the driving piston hole on the working end side of the oil unloading piston hole through the fluid channel in the box body at the same time, 2) The fluid pressure overcomes the force of the return spring, pushing the oil unloading piston from the oil supply position to the oil unloading position, connecting the oil unloading passage of the oil unloading piston with the driving piston hole on the non-working end side of the driving piston to discharge fluid; 3) The driving piston moves to the operating position, pushing the starting mechanism to the starting state, 4) The engine's valve drive mechanism opens the engine's valves, 5) The starting mechanism reaches the starting state and acts on the return valve bridge or valve, so that the opened valve cannot return to its seat and remains open. 6) The engine is stopped, the starting mechanism is still in the starting state, and the valve remains open, 7) The oil unloading piston returns from the oil unloading position to the oil supply position under the action of the return spring. 8) Engine starting, the starting mechanism keeps the valve open to reduce the torque of the engine starting, 9) The fluid enters the driving piston hole on the non-working end side of the driving piston through the fluid channel in the housing and the oil supply groove on the oil unloading piston, and the driving piston moves to the non-operating position, pushing the starting mechanism to the non-starting state, separating from the valve bridge or valve, and the valve returns to its seat and closes, and 10) The engine is ignited, and the fluid pressure acting on the non-working end keeps the drive piston in the non-operating position, and the starting mechanism remains in the non-starting state and is separated from the valve bridge or the valve.

9. The method for reducing engine starting torque according to claim 8, wherein: The starting mechanism includes a swinging mechanism, which includes a swinging member installed on a swinging shaft, which is installed on a box body. The swinging member includes a connecting end and a working end. The connecting end of the swinging member is connected to a driving piston, which drives the swinging member to swing between a non-starting state and a starting state. In the non-starting state, the working end of the swinging member is separated from the valve bridge or valve; in the starting state, the working end of the swinging member acts on the valve bridge or valve.

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