Valve bridge, brake actuator, exhaust brake system, method and engine

Abstract

The present invention discloses a valve bridge, a brake actuator, an exhaust brake system, a method and an engine, wherein the valve bridge comprises a valve bridge body, a sliding valve, a piston-connecting rod assembly, a first reset member and a second reset member, wherein a brake valve clearance is provided between the sliding valve and the valve bridge body; the sliding valve is slidably arranged in the middle of the valve bridge body and is provided with an oil inlet state and an oil drain state; the piston-connecting rod assembly is located between the sliding valve and the valve bridge body and is provided with a locked state and an unlocked state; the first reset member is used to drive the sliding valve to reset; the second reset member is used to drive the piston-connecting rod assembly to reset; in the embodiment of the present invention, the brake valve clearance is located in the middle of the valve bridge, therefore, during the exhaust brake process, the middle of the valve bridge is subjected to force, and the force is evenly applied without causing tilting, thereby improving the stability of the valve bridge when returning and reducing the impact when the valve bridge returns.

Description

Technical Field

[0001] The present invention relates to the technical field of engines, and in particular to a valve bridge, a brake actuator, an exhaust brake system, a method and an engine. Background Art

[0002] The brake actuator includes a brake rocker arm and a valve bridge. A brake valve clearance exists between the brake rocker arm and the valve bridge. A movable actuator pin is provided at one end of the valve bridge, which can push open the exhaust valve. When the brake rocker arm is not performing a braking action, the actuator pin is not pressed, the exhaust valve is closed, and the brake actuator is in a brake valve clearance maintaining state. When the brake rocker arm is performing a braking action, the actuator pin is pressed, the exhaust valve opens, and the brake actuator is in a brake valve clearance eliminating state. When the brake actuator is in the brake valve clearance eliminating state, the brake rocker arm presses one end of the valve bridge, causing the valve bridge to tilt. When the valve bridge returns to its original position, it is unstable and there is impact.

[0003] Therefore, how to solve the problem of valve bridge tilting during exhaust braking to improve the stability of the valve bridge when it returns and reduce the impact when the valve bridge returns has become a technical problem that needs to be solved urgently by those skilled in the art. Summary of the Invention

[0004] The present invention proposes a valve bridge, a brake actuator, an exhaust brake system, a method and an engine to reduce the oil leakage of the solenoid valve, to solve the problem of the valve bridge tilting during the exhaust brake process, to improve the stability of the valve bridge when returning, and to reduce the impact when the valve bridge returns.

[0005] In order to achieve the above-mentioned objectives, the present invention discloses a valve bridge, comprising a valve bridge body, a sliding valve, a piston-connecting rod assembly, a first reset member and a second reset member, wherein a brake valve clearance is provided between the sliding valve and the valve bridge body; the sliding valve is slidably arranged in the middle of the valve bridge body, and is configured with an oil inlet state and an oil drain state; the piston-connecting rod assembly is located between the sliding valve and the valve bridge body, and is configured with a locked state and an unlocked state; the first reset member is used to drive the sliding valve to reset; the second reset member is used to drive the piston-connecting rod assembly to reset; when the sliding valve is in the oil inlet state, the pressure oil between the sliding valve and the valve bridge body pushes the piston-connecting rod assembly to the unlocked state, and the brake valve clearance is maintained; when the sliding valve is in the oil drain state, the first reset member drives the sliding valve to reset, and the second reset member drives the piston-connecting rod assembly to reset to the locked state, and the brake valve clearance is eliminated.

[0006] In the valve bridge of an embodiment of the present invention, the valve bridge body includes a sliding cavity, a first guide groove, a second guide groove, a first port and a first oil channel, wherein the sliding cavity is located in the middle of the valve bridge body for accommodating the movement of the sliding valve; the first guide groove and the second guide groove are used to accommodate the movement of the piston connecting rod assembly; the first port is located on the inner wall of the sliding cavity for communicating with the sliding valve; the first oil channel connects the first guide groove and the first port.

[0007] In the valve bridge of an embodiment of the present invention, the first oil channel is arranged on the inner wall of the valve bridge body; the first port is a straight hole extending along the first direction, and the first oil channel is a straight hole along the second direction; the first oil channel is located at one end of the end face of the valve bridge body and is provided with a first seal, and the first seal is used to seal the first oil channel; the first port is located at one end of the peripheral surface of the valve bridge body and is provided with a second seal, and the second seal is used to seal the first port; the first direction is perpendicular to the second direction.

[0008] In the valve bridge of the embodiment of the present invention, a first retaining groove for limiting the sliding valve from separating from the valve bridge body is provided on the sliding cavity, and a first retaining ring is provided in the first retaining groove.

[0009] In the valve bridge of the embodiment of the present invention, the slide valve is movable between a first position and a second position, wherein a distance between the first position and the second position in the second direction is equal to the brake valve clearance;

[0010] When the sliding valve moves to the first position, the first retaining ring limits the sliding valve from continuing to move to prevent the sliding valve from separating from the valve bridge body; when the sliding valve remains in the first position, the brake valve clearance is eliminated; the sliding valve can move between the first position and the second position, and the brake valve clearance is maintained.

[0011] In the valve bridge of the embodiment of the present invention, the second guide groove is provided with a second clamping groove for limiting the piston connecting rod assembly from being separated from the valve bridge body, and a second retaining ring is provided in the second clamping groove.

[0012] In the valve bridge of the embodiment of the present invention, when the second return member is located in the second guide groove, a gasket is further provided between the second retaining ring and the second return member.

[0013] In the valve bridge of an embodiment of the present invention, the sliding valve includes a second port, a third port and a second oil channel, wherein the second port is connected to the third port through the second oil channel. When oil is admitted to the second port, the pressure oil flows to the third port through the second oil channel via the second port; when oil is discharged from the second port, the pressure oil flows to the second port through the second oil channel via the third port.

[0014] In the valve bridge of the embodiment of the present invention, the second oil passage is arranged along the housing wall of the sliding valve.

[0015] In the valve bridge of the embodiment of the present invention, the number of the second oil passages is four, and one second oil passage corresponds to one third port.

[0016] In the valve bridge of the embodiment of the present invention, the second oil passage is communicated with the second port through the third oil passage.

[0017] In the valve bridge of the embodiment of the present invention, the third oil passage is arranged obliquely.

[0018] In the valve bridge of the embodiment of the present invention, the second port is located at the top of the slide valve, and the diameter of the second port is larger than the diameter of the third oil passage.

[0019] In the valve bridge of the embodiment of the present invention, an annular oil groove is provided on the circumference of the slide valve, the third port is located at the bottom of the annular oil groove, and the width of the annular oil groove is greater than the diameter of the third port.

[0020] In the valve bridge of the embodiment of the present invention, the slide valve is further provided with a compression groove for accommodating the first return member, one end of the first return member abuts against the compression groove, and the other end of the first return member abuts against the bottom wall of the sliding cavity.

[0021] In the valve bridge of the embodiment of the present invention, a third guide groove for accommodating the actuator of the piston-connecting rod assembly is provided at one end of the sliding valve close to the piston-connecting rod assembly, and the actuator of the piston-connecting rod assembly is slidably provided in the third guide groove.

[0022] In the valve bridge of an embodiment of the present invention, the piston-connecting rod assembly includes a first piston, a second piston, a third piston, a first connecting rod, a second connecting rod and a third connecting rod, wherein the first end of the first connecting rod is rotatably connected to the first piston; the first end of the second connecting rod is rotatably connected to the second piston; the first end of the third connecting rod is rotatably connected to the third piston; the second end of the first connecting rod, the second end of the second connecting rod and the second end of the third connecting rod are all rotatably connected; the first piston is slidably arranged in the third guide groove, the second piston is slidably arranged in the first guide groove, and the third piston is slidably arranged in the second guide groove.

[0023] In the valve bridge of an embodiment of the present invention, the parts where the first connecting rod, the second connecting rod, the third connecting rod, the first piston, the second piston and the third piston cooperate with each other are provided with a rotating part or a rotating groove, so that the rotating part is inserted into the rotating groove and is rotatably connected through the corresponding rotating shaft.

[0024] The present invention also discloses a brake actuator, comprising an exhaust rocker arm and a valve bridge, wherein a pad of the exhaust rocker arm cooperates with the valve bridge, and the valve bridge is any one of the valve bridges described above.

[0025] The present invention also discloses an exhaust brake system, including a controller, a solenoid valve and a brake actuator, wherein the brake actuator is the above-mentioned brake actuator; the controller controls the conduction state of the solenoid valve to achieve conduction or cutoff of the brake actuator and the engine oil supply, thereby switching the brake actuator between the brake valve clearance maintaining state and the elimination state.

[0026] The present invention also discloses an exhaust braking method, which is based on the exhaust braking system as described above and includes:

[0027] Obtain engine operating parameters;

[0028] Compare whether the operating parameters meet the preset requirements;

[0029] If the preset requirements are met, it is determined that the engine needs to be switched to the braking state, and the solenoid valve is energized;

[0030] If the preset requirements are not met, it is determined that the engine needs to be switched to the positive power state and the solenoid valve is de-energized.

[0031] The present invention also discloses an engine comprising the exhaust brake system as described above.

[0032] As can be seen from the above technical solution, the brake valve clearance in this embodiment of the present invention is located in the middle of the valve bridge. Therefore, during exhaust braking, the force is evenly applied to the middle of the valve bridge, preventing tilt. This improves the stability of the valve bridge during return and reduces impact during return. Furthermore, the exhaust rocker arm and the corresponding valve bridge in this embodiment of the present invention provide exhaust braking functionality, eliminating the need for a separate brake rocker arm and reducing costs. Furthermore, the absence of a brake rocker arm reduces the space occupied by the valve train or brake actuator, contributing to engine compactness. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some examples or embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on the provided drawings without inventive work, and the present invention can also be applied to other similar scenarios based on the provided drawings. Unless otherwise apparent from the language context or otherwise explained, the same reference numerals in the figures represent the same structure or operation.

[0034] Figure 1 A diagram showing the relationship between valve lift and crankshaft angle provided by the present invention;

[0035] Figure 2 A partial three-dimensional diagram of a valve mechanism provided by the present invention;

[0036] Figure 3 A schematic diagram of an exhaust brake system provided by the present invention;

[0037] Figure 4 A diagram of a valve bridge state switching process provided by the present invention;

[0038] Figure 5 A partial three-dimensional diagram of another valve mechanism provided by the present invention

[0039] Figure 6 An exploded view of a valve bridge provided by the present invention;

[0040] Figure 7 A three-dimensional diagram of a valve bridge provided by the present invention;

[0041] Figure 8 for Figure 7 Cross-sectional view of section AA;

[0042] Figure 9 A three-dimensional diagram of a valve bridge body provided by the present invention at different angles;

[0043] Figure 10 for Figure 9 Cross-sectional view of the middle BB section;

[0044] Figure 11 for Figure 9 Cross-sectional view of the CC section;

[0045] Figure 12 A three-dimensional diagram of a slide valve provided by the present invention;

[0046] Figure 13 for Figure 12 Cross-sectional view of the middle DD section;

[0047] Figure 14 A three-dimensional diagram of a piston-connecting rod assembly provided by the present invention;

[0048] Figure 15 An exploded view of a piston-connecting rod assembly provided by the present invention;

[0049] Figure 16 A schematic diagram of another exhaust brake system provided by the present invention in a positive power state;

[0050] Figure 17 A schematic diagram of another exhaust brake system provided by the present invention in a braking state;

[0051] Figure 18 A schematic flow chart of another exhaust braking method provided by the present invention;

[0052] In the figure, 100 is the controller, 200 is the solenoid valve, 300 is the brake actuator, and 400 is the engine oil supply;

[0053] 301 is the brake rocker arm, 302 is the valve bridge, 303 is the valve, 304 is the intake rocker arm, and 305 is the exhaust rocker arm; 302a is the first end, 302b is the second end, 3021 is the actuator pin, 3022 is the valve bridge body, 3023 is the slide valve, 3024 is the piston connecting rod assembly, 3025 is the first return member, 3026 is the second return member, 30271 is the first retaining ring, 30272 is the second retaining ring, 30273 is the gasket, and 3051 is the cushion block;

[0054] 3022a is the sliding cavity, 3022b is the first port, 3022c is the first oil channel, 3022d is the first guide groove, 3022e is the second guide groove, 3022f is the first seal, and 3022g is the second seal;

[0055] 3023a is the second port, 3023b is the third port, 3023c is the second oil passage, 3023d is the third seal, 3023e is the third guide groove, 3023f is the compression groove, 3023g is the third oil passage, 2023h is the annular oil groove, and 2023i is the step surface;

[0056] 30241 is the first piston, 30242 is the second piston, 30243 is the third piston, 30244 is the first connecting rod, 30245 is the second connecting rod, 30246 is the third connecting rod, 30247a is the first rotating shaft, 30247b is the second rotating shaft, 30247c is the third rotating shaft, and 30247d is the fourth rotating shaft. DETAILED DESCRIPTION

[0057] The present invention will be further described in detail below with reference to the accompanying drawings and examples. It will be understood that the specific embodiments described herein are intended only to explain the relevant invention and are not intended to limit the invention. The embodiments described are merely some embodiments of the present invention, not all embodiments. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present invention without creative effort are intended to fall within the scope of protection of the present invention.

[0058] Engine: A machine that converts other forms of energy into mechanical energy, including internal combustion engines (reciprocating piston engines), external combustion engines (Stirling engines, steam engines, etc.), jet engines, electric motors, etc. Usually includes a valve train.

[0059] Engine braking refers to the use of the compression resistance, internal friction and intake and exhaust resistance generated by the engine's compression stroke to brake the drive wheels.

[0060] Top Dead Center: The position where the piston top reaches the highest point when it moves in the cylinder, that is, the piston top is farthest from the center of rotation of the crankshaft.

[0061] Bottom Dead Center: The position where the piston top reaches the lowest point when it moves in the cylinder, that is, the piston top is closest to the center of rotation of the crankshaft.

[0062] The valve mechanism opens and closes the intake and exhaust valves of each cylinder at a regular interval according to the working order of each cylinder of the engine and the requirements of the working cycle of each cylinder, cooperating with the engine cylinders to realize the working processes of intake, compression, power and exhaust.

[0063] Rocker arm: A valve train component. It can be considered a lever, amplifying the cam lift by a certain ratio (the rocker arm ratio) and transmitting it to the valve. The cam side typically uses a roller to roll with the cam, while the valve side typically has a pad (elephant foot) in contact with the valve bridge. Based on their function, they can be divided into intake rocker arms, exhaust rocker arms, and brake rocker arms. The intake rocker arm connects to the valve bridge corresponding to the intake valve to open it; the exhaust rocker arm connects to the valve bridge corresponding to the exhaust valve to open it; and the brake rocker arm connects to the valve bridge corresponding to the exhaust valve to open it.

[0064] Exhaust brake: also known as engine compression release brake. Specifically, it refers to a braking method in which the engine stops injecting fuel and opens the exhaust valve near the top dead center to release the compressed energy in the cylinder, causing the engine to do negative work. During the exhaust braking process, in order to eliminate the influence of the cam profile on the positive work, it is necessary to set the brake valve clearance h. When the engine is doing positive work, the brake valve clearance is maintained to eliminate the brake valve lift; when the engine is braking, the brake valve clearance is eliminated to allow the brake valve lift to be transmitted to the valve. By controlling the size of the brake valve clearance, the switching between the positive work valve lift and the brake valve lift can be achieved, such as Figure 1 shown.

[0065] See also Figure 2 , Figure 2 A partial perspective view of a valve train is shown; the valve train shown includes an intake rocker arm 304, an exhaust rocker arm 305, a brake rocker arm 301, valves 303, and a valve bridge 302. A valve 303 is disposed at each end of the valve bridge 302, and the valves 303 at both ends of the valve bridge 302 are either intake valves or exhaust valves. The intake rocker arm 304 is connected to the valve bridge 302 corresponding to the intake valve 303 to open the intake valve 303; the exhaust rocker arm 305 is connected to the valve bridge 302 corresponding to the exhaust valve to open the exhaust valve; and the brake rocker arm 301 is connected to the valve bridge 302 corresponding to the exhaust valve to open the exhaust valve.

[0066] See also Figure 3 , Figure 3An exhaust brake system is illustrated; the exhaust brake system shown is used to perform the aforementioned exhaust brake. The exhaust brake system includes a controller 100, a solenoid valve 200, and a brake actuator 300. The controller 100 controls the conduction state of the solenoid valve 200 to connect or disconnect the brake actuator 300 from the engine oil supply 400, thereby switching the brake actuator 300 between a brake valve lash maintaining state and a brake valve lash elimination state. Specifically, when the controller 100 controls the solenoid valve 200 to de-energize, the solenoid valve 200 is in a first conduction state, and the brake actuator 300 is in a brake valve lash maintaining state. When the controller 100 controls the solenoid valve 200 to energize, the solenoid valve 200 is in a second conduction state, and the brake actuator 300 is in a brake valve lash elimination state. The brake valve lash maintaining state corresponds to positive valve lift, and the brake valve lash elimination state corresponds to brake valve lift.

[0067] The controller 100 is used to control the power on or off of the solenoid valve 200100 and can be an ECU (Electronic Control Unit). Any control structure that can achieve the above operations can be used as the controller 100.

[0068] Figure 2 The brake rocker arm 301 and the valve bridge 302 corresponding to the exhaust valve can be used as Figure 3 The brake actuator 300 shown in the figure has a brake valve clearance between the brake rocker arm 301 and the valve bridge 302; a movable actuator pin 3021 is provided at one end of the valve bridge 302, and the actuator pin 3021 can push open the exhaust valve; when the brake rocker arm 301 does not perform the braking action, the actuator pin 3021 is not pressed, as shown in FIG. Figure 4 As shown in (a), the exhaust valve is closed and the brake actuator 300 is in the brake valve clearance maintaining state; when the brake rocker arm 301 performs the braking action, the actuator pin 3021 is pressed, as shown in FIG. Figure 4 As shown in (b), the exhaust valve is open and the brake actuator 300 is in the brake valve clearance elimination state. During the process from not being pressed to being pressed, the distance h1 of the actuator pin 3021 is equal to the brake valve clearance.

[0069] When the brake actuator 300 is in the brake valve clearance elimination state, the brake rocker arm 301 presses one end of the valve bridge 302, causing the valve bridge 302 to tilt. This makes the valve bridge 302 unstable and causes impact when returning to its original position. Furthermore, since the brake actuator 300 requires a separate brake rocker arm 301, the cost is high. Furthermore, the brake rocker arm 301 occupies a large space, hindering the compactness of the engine. During braking, the hydraulic oil chamber of the brake rocker arm 301 has high pressure, resulting in hydraulic loss and causing loss of brake valve lift.

[0070] To address the problem of valve bridge 302 tilting during exhaust braking, improve the stability of valve bridge 302 during return, and reduce the impact of valve bridge 302 returning to its original position, the present invention improves the structure of valve bridge 302 so that the valve clearance is located in the middle of valve bridge 302, thereby addressing the problem of valve bridge 302 tilting during exhaust braking. The structure of valve bridge 302 is described in detail below with reference to the accompanying drawings to facilitate understanding.

[0071] See also Figure 5 , Figure 5 A three-dimensional diagram of a partial valve train is shown; the valve train shown includes an intake rocker arm 304, an exhaust rocker arm 305, a valve 303, and a valve bridge 302. A valve 303 is disposed at each end of the valve bridge 302, and the valves 303 at each end of the valve bridge 302 are either intake valves or exhaust valves. The intake rocker arm 304 is connected to the valve bridge 302 corresponding to the intake valve 303 to open the intake valve 303; the exhaust rocker arm 305 is connected to the valve bridge 302 corresponding to the exhaust valve to open the exhaust valve. The exhaust rocker arm 305 and the valve bridge 302 corresponding to the exhaust valve can function as a brake actuator 300. A brake valve clearance exists between the exhaust rocker arm 305 and the valve bridge 302. When the brake actuator 300 is in the brake valve clearance maintaining state, the brake valve clearance is maintained; when the brake actuator 300 is in the brake valve clearance eliminating state, the brake valve clearance is eliminated.

[0072] Because the brake valve clearance in this embodiment of the present invention is located in the middle of the valve bridge 302, during exhaust braking, the center of the valve bridge 302 is evenly stressed without tilting. This improves the stability of the valve bridge 302 during its return and reduces impact during return. Furthermore, the exhaust rocker arm 305 and the corresponding valve bridge 302 in this embodiment of the present invention provide exhaust braking functionality, eliminating the need for a separate brake rocker arm 301 and reducing costs. Furthermore, since no brake rocker arm 301 is required, the space occupied by the valve train or brake actuator 300 is reduced, contributing to engine compactness.

[0073] See also Figures 6 to 8 , Figure 6 An exploded view of a valve bridge 302 is shown; Figure 7 A perspective view of a valve bridge 302 is shown; Figure 8 for Figure 7The valve bridge 302 shown in the figure includes a valve bridge body 3022, a sliding valve 3023, a piston connecting rod assembly, a first return member 3025 and a second return member 3026, wherein the brake valve clearance is between the sliding valve 3023 and the valve bridge body 3022; the sliding valve 3023 is slidably arranged in the middle of the valve bridge body 3022 and is configured with an oil inlet state and an oil drain state; the piston connecting rod assembly is located between the sliding valve 3023 and the valve bridge body 3022 and is configured with a locked state and an unlocked state; the first return member 3025 is configured with ... Component 3025 is used to drive the sliding valve 3023 to reset; the second reset component 3026 is used to drive the piston connecting rod assembly to reset; when the sliding valve 3023 is in the oil inlet state, the pressure oil between the sliding valve 3023 and the valve bridge body 3022 pushes the piston connecting rod assembly to the unlocked state, and the brake valve clearance is maintained; when the sliding valve 3023 is in the oil leakage state, the first reset component 3025 drives the sliding valve 3023 to reset, and the second reset component 3026 drives the piston connecting rod assembly to reset to the locked state, and the brake valve clearance is eliminated.

[0074] The terms "first" and "second" are used for descriptive purposes only and should not be understood to indicate or imply relative importance or implicitly specify the number of technical features indicated. Therefore, features specified as "first" or "second" may explicitly or implicitly include one or more of the features.

[0075] Because the valve bridge of the present invention does not require an actuator pin, opening both valves simultaneously eliminates valve bridge tilt and provides excellent stability. Under braking, force is transmitted through the mechanical structure, eliminating the need for a high-pressure oil chamber and hydraulic lift loss, resulting in high valve lift accuracy.

[0076] Combine Figure 8 , see Figures 9 to 11 The above-mentioned valve bridge body 3022 is used to support the sliding valve 3023, the piston connecting rod assembly 3024, the first return member 3025 and the second return member 3026, wherein the first end 302a of the valve bridge body 3022 is provided with a first mounting hole 302a1, the first mounting hole 302a1 is used to install the valve 303, the second end 302b of the valve bridge body 3022 is provided with a second mounting hole 302b1, the second mounting hole 302b1 is used to install another valve 303, and the brake valve clearance h is located in the middle of the valve bridge body 3022. It should be noted that the first end and the second end of the valve bridge body 3022 are distinguished according to the length direction of the valve bridge 3022. The length direction of the valve bridge body 3022 corresponds to the third direction, the axial direction of the valve bridge body 3022 corresponds to the second direction, and the width direction of the valve bridge body 3022 corresponds to the first direction. The first direction, the second direction and the third direction are perpendicular to each other. The first direction corresponds to the y direction, the second direction corresponds to the z direction, and the third direction corresponds to the x direction.

[0077] Specifically, the valve bridge body 3022 shown in the figure includes a sliding cavity 3022a, a first guide groove 3022d, a second guide groove 3022e, a first port 3022b and a first oil channel 3022c, wherein the sliding cavity 3022a is located in the middle of the valve bridge body 3022 for accommodating the movement of the sliding valve 3023; the first guide groove 3022d and the second guide groove 3022e are used to accommodate the movement of the piston connecting rod assembly 3024; the first port 3022b is located on the inner wall of the sliding cavity 3022a and is connected to the sliding cavity 3022a for communicating with the sliding valve 3023; the first oil channel 3022c is connected to the first guide groove 3022d and the first port 3022b.

[0078] The first oil passage 3022c is disposed on the inner wall of the valve bridge body 3022 and can extend in the second direction or be arranged at an angle. To facilitate processing, the first oil passage 3022c is a straight hole extending in the second direction, while the first port 3022b is a straight hole extending in the first direction. A first seal 3022f is provided at one end of the first oil passage 3022c located on the end surface of the valve bridge body 3022. The first seal 3022f is used to seal the first oil passage 3022c. A second seal 3022g is provided at one end of the first port 3022b located on the circumference of the valve bridge body 3022. The second seal 3022g is used to seal the first port 3022b located on the circumference of the valve bridge body 3022.

[0079] The sliding cavity 3022a is provided with a first retaining groove that prevents the sliding valve 3023 from disengaging from the valve bridge 3022. A first retaining ring 30271 is disposed within the first retaining groove. The sliding valve 3023 can move between a first position and a second position in the second direction. The distance between the first position and the second position in the second direction is equal to the brake valve clearance h. When the sliding valve 3023 moves to the first position, the first retaining ring 30271 restricts further movement of the sliding valve 3023, preventing it from disengaging from the valve bridge 3022. When the sliding valve 3023 remains in the first position, the brake valve clearance is eliminated. While the sliding valve 3023 is movable between the first and second positions, the brake valve clearance is maintained.

[0080] The second guide groove 3022e is provided with a second retaining groove to prevent the piston connecting rod assembly 3024 from disengaging from the valve bridge body 3022. A second retaining ring 30272 is disposed within the second retaining groove. In the first direction, the control portion of the piston connecting rod assembly 3024 is movable between a third position and a fourth position. When the control portion of the piston connecting rod assembly 3024 is moved to the third position, the spool valve 3023 remains in the first position. When the control portion of the piston connecting rod assembly 3024 is moved to the fourth position, the spool valve 3023 is movable between the first and second positions, maintaining brake valve clearance.

[0081] Furthermore, when the second restoring member 3026 is located in the second guide groove 3022e, in order to reduce the contact between the second retaining ring 30272 and the second restoring member 3026, a gasket 30273 may be further provided between the second retaining ring 30272 and the second restoring member 3026.

[0082] Combine Figure 8 , see Figure 12 and Figure 13 There is a brake valve clearance between the sliding valve 3023 and the valve bridge body 3022 shown in the figure, and the sliding valve 3023 is configured with an oil inlet state and an oil drain state; when the sliding valve 3023 is in the oil inlet state, oil is fed into the valve bridge body 3022 through the sliding valve 3023; when the sliding valve 3023 is in the oil drain state, the pressure oil in the valve bridge body 3022 is drained through the sliding valve 3023.

[0083] Specifically, the sliding valve 3023 includes a second port 3023a, a third port 3023b and a second oil passage 3023c, wherein the second port 3023a is connected to the third port 3023b through the second oil passage 3023c. When oil enters the second port 3023a, the pressure oil flows from the second port 3023a to the third port 3023b through the second oil passage 3023c; when oil is discharged from the second port 3023a, the pressure oil flows from the third port 3023b to the second port 3023a through the second oil passage 3023c.

[0084] The second oil passage 3023c can be arranged along the housing wall of the sliding valve 3023. The second oil passage 3023c can extend in the second direction, be arranged at an angle, or be arranged in a spiral. To facilitate manufacturing, the second oil passage 3023c is formed as a straight hole extending in the second direction. A third seal 3023d is provided near the end surface of the chute 3023. The third seal 3023d is used to seal the end of the second oil passage 3023c near the end surface of the chute 3023.

[0085] The number of second oil passages 3023c can be one or more. One second oil passage 3023c can correspond to one third port 3023b, one second oil passage 3023c can correspond to multiple third ports 3023b, multiple second oil passages 3023c can correspond to one third port 3023b, or multiple second oil passages 3023c can correspond to multiple third ports 3023b. In the figure, there are four second oil passages 3023c, with one second oil passage 3023c corresponding to one third port 3023b. Furthermore, the four second oil passages 3023c are evenly distributed on the housing wall of the slide valve 3023.

[0086] Second oil passage 3023c communicates directly with second port 3023a, or communicates with second port 3023a via third oil passage 3023g. When second oil passage 3023c communicates with second port 3023a via third oil passage 3023g, one third oil passage 3023g corresponds to one second oil passage 3023c. While third oil passage 3023g is illustrated as being arranged at an angle, third oil passage 3023g can also be arranged in a curved configuration. Any configuration that achieves communication between second port 3023a and third oil passage 3023g falls within the scope of the present invention.

[0087] The second port 3023a is located at the top of the sliding valve 3023 to facilitate cooperation with the gasket 3051 of the exhaust rocker arm 305. The diameter of the second port 3023a is larger than the diameter of the third oil channel 3023g, so that some pressurized oil is stored in the second port 3023a to facilitate rapid switching between the positive power state and the braking state.

[0088] To optimize the above technical solution, in this embodiment of the present invention, an annular oil groove 2023h is provided on the circumference of the spool valve 3023. The third port 3023b is located at the bottom of the annular oil groove 2023h. The width of the annular oil groove 2023h is greater than the diameter of the third port 3023b. The provision of the annular oil groove 2023h allows the third port 3023b to communicate with the second port 3023a at any angle of the spool valve 3023, thereby simplifying the installation of the spool valve 3023 and the valve bridge body 3022.

[0089] Furthermore, the circumferential surface of the sliding valve 3023 is provided with a step surface 2023i that cooperates with the above-mentioned first retaining ring 30271. When the step surface 2023i contacts the first retaining ring 30271, the sliding valve 3023 is in the first position.

[0090] In order to improve the compactness of the valve bridge 302 and reduce the volume of the valve bridge 302, in some embodiments of the present invention, a third guide groove 3023e for accommodating the actuator of the piston connecting rod assembly 3024 is provided at one end of the sliding valve 3023 close to the piston connecting rod assembly 3024, and the actuator of the piston connecting rod assembly 3024 can be slidably arranged in the third guide groove 3023e.

[0091] Furthermore, the spool valve 3023 is provided with a compression groove 3023f for accommodating the first return member 3025. One end of the first return member 3025 abuts the compression groove 3023f, while the other end abuts the bottom wall of the sliding cavity 3022a. When the spool valve 3023 is in the oil-draining state, the spool valve 3023 is driven by the first return member 3025 to return to and remain in the first position, eliminating the brake valve clearance. When the spool valve 3023 is in the oil-intake state, the control end of the piston connecting rod assembly 3024 moves in the first direction under the pressure of the pressurized oil, maintaining the brake valve clearance between the spool valve 3023 and the valve bridge body 3022, allowing the spool valve 3023 to move within the brake valve clearance range.

[0092] Combine Figure 8 , refer to Figure 14 and Figure 15 The piston-connecting rod assembly 3024 shown in the figure functions to maintain or eliminate the brake valve clearance between the spool valve 3023 and the valve bridge body 3022 by changing its shape. The piston-connecting rod assembly 3024 comprises a control unit and an actuator. The control unit, under the action of pressure oil and a second return member 3026, locks and unlocks the actuator. When the actuator is locked, it lifts the spool valve 3023, maintaining it in the first position and eliminating the brake valve clearance. When the actuator is unlocked, a free gap h2 exists between the actuator and the spool valve 3023, enabling the spool valve 3023 to move within the free gap h2, maintaining the brake valve clearance. It is understood that the free gap h2 is equal to the brake valve clearance.

[0093] Specifically, the piston-connecting rod assembly 3024 includes a first piston 30241, a second piston 30242, a third piston 30243, a first connecting rod 30244, a second connecting rod 30245 and a third connecting rod 30246. The first end of the first connecting rod 30244 is rotatably connected to the first piston 30241; the first end of the second connecting rod 30245 is rotatably connected to the second piston 30242; the first end of the third connecting rod 30246 is rotatably connected to the third piston 30243; the second end of the first connecting rod 30244, the second end of the second connecting rod 30245 and the second end of the third connecting rod 30246 are all rotatably connected; the first piston 30241 is slidably arranged in the third guide groove 3023e, the second piston 30242 is slidably arranged in the first guide groove 3022d, and the third piston 30243 is slidably arranged in the second guide groove 3022e. The first piston 30241 can be understood as the actuator of the piston-connecting rod assembly 3024 , and the second piston 30242 and the third piston 30243 can be understood as the control part of the piston-connecting rod assembly 3024 .

[0094] When the sliding valve 3023 is in the oil leakage state, the second piston 30242 and the third piston 30243 are reset to the locked state under the action of the second reset member 3026; when the sliding valve 3023 is in the oil supply state, the second piston 30242 and the third piston 30243 move to the unlocked state under the action of the pressure oil.

[0095] There are many ways to achieve a rotatable connection between the first connecting rod 30244 and the first piston 30241, such as setting a first rotating shaft 30247a, which extends along a third direction, so that the first piston 30241 and the first connecting rod 30244 can rotate around the axis of the first rotating shaft 30247a as the rotation center, wherein the axis of the first rotating shaft 30247a is parallel to the third direction.

[0096] There are many ways to achieve a rotatable connection between the second connecting rod 30245 and the second piston 30242, such as setting a second rotating shaft 30247b, which extends along a third direction, so that the second piston 30242 and the second connecting rod 30245 can rotate around the axis of the second rotating shaft 30247b as the rotation center, wherein the axis of the second rotating shaft 30247b is parallel to the third direction.

[0097] There are many ways to achieve a rotatable connection between the third connecting rod 30246 and the third piston 30243, such as setting a third rotating shaft 30247c, which extends along the third direction, so that the third piston 30243 and the third connecting rod 30246 can rotate around the axis of the third rotating shaft 30247c as the rotation center, wherein the axis of the third rotating shaft 30247c is parallel to the third direction.

[0098] There are many ways to achieve rotatable connection between the first link 30244, the second link 30245 and the third link 30246, such as setting a fourth rotating shaft 30247d, which extends along the third direction, so that the first link 30244, the second link 30245 and the third link 30246 can rotate around the axis of the fourth rotating shaft 30247d as the rotation center, wherein the axis of the fourth rotating shaft 30247d is parallel to the third direction.

[0099] In order to improve the stability of the connection force between the first connecting rod 30244, the second connecting rod 30245, the third connecting rod 30246, the first piston 30241, the second piston 30242 and the third piston 30243, the parts that cooperate with each other between the first connecting rod 30244, the second connecting rod 30245, the third connecting rod 30246, the first piston 30241, the second piston 30242 and the third piston 30243 are provided with a rotating part or a rotating groove, so that the rotating part is inserted into the rotating groove and is rotatably connected through the corresponding rotating shaft.

[0100] The above discloses a case where there are three pistons. In some embodiments of the present invention, there can also be two pistons, namely a fourth piston and a fifth piston, wherein one end of the fourth piston is rotatably connected to the first end of the fourth connecting rod; the second end of the fourth connecting rod is rotatably connected to the middle part of the fifth piston; the fourth piston is slidably arranged in the third guide groove, and the fifth piston is slidably arranged in the first guide groove and the second guide groove; the second reset member in the second guide groove can drive the fifth piston to reset; the pressure oil in the first guide groove can push the fifth piston to move along the first direction.

[0101] See also Figures 16 and 17 The figure discloses an exhaust brake system, including a controller 100, a solenoid valve 200, and a brake actuator 300. The controller 100 controls the conduction state of the solenoid valve 200 to achieve conduction or cutoff between the brake actuator 300 and the engine oil supply 400, thereby switching the brake actuator 300 between a brake valve clearance maintaining state and a brake valve clearance elimination state. Specifically, when the controller 100 controls the solenoid valve 200 to de-energize, the solenoid valve 200100 is in a first conduction state, and the brake actuator 300 is in a brake valve clearance maintaining state; when the controller 100 controls the solenoid valve 200 to energize, the solenoid valve 200100 is in a second conduction state, and the brake actuator 300 is in a brake valve clearance elimination state. The brake valve clearance maintaining state corresponds to positive valve lift, and the brake valve clearance elimination state corresponds to brake valve lift.

[0102] The brake actuator 300 includes an exhaust rocker arm 305 and a valve bridge 302. The valve bridge 302 is Figures 5 to 15 Valve bridge 302 is shown.

[0103] The following describes the operation process of the exhaust brake system in detail with reference to the accompanying drawings:

[0104] When the engine is in the positive power state, the controller 100 controls the solenoid valve 200 to be de-energized, and the engine oil supply 400 is delivered to the position of the gasket 3051 of the exhaust rocker arm 305 through the solenoid valve 200. The pressure oil enters the second port 3023a of the slide valve 3023 through the oil channel of the gasket 3051, and then enters the first port 3022b of the valve bridge body 3022 from the annular oil groove 2023h of the slide valve 3023. The pressure oil in the first guide groove 3022d overcomes the spring force of the first return member 3025, pushing the second piston 30242 and the third piston 30243 to move in the first direction to the maximum stroke position, and is then driven by the gasket 30273 and the second retaining ring. 30272 limit, at the same time, the movement of the second piston 30242 and the third piston 30243 in the first direction causes the first piston 30241 to be pulled by the connecting rod and move downward in the second direction, and an active gap h2 appears between the first piston 30241 and the sliding valve 3023. Only when the exhaust rocker arm 305 moves downward and eliminates the active gap h2 between the sliding valve 3023 and the valve bridge body 3022, the exhaust rocker arm 305 can continue to move downward to open the exhaust valve. The movement of the exhaust rocker arm 305 caused by the brake cam lift can be completely offset by the active gap h2 between the sliding valve 3023 and the valve bridge body 3022, without affecting the positive valve lift. Figure 16 shown.

[0105] When the engine switches to the braking state, the controller 100 controls the solenoid valve 200 to be energized, and there is no longer oil pressure at the second piston 30242. The second reset member 3026 pushes the third piston 30243 and the second piston 30242 to move leftward along the second direction to the limit position. The translation of the second piston 30242 and the third piston 30243 causes the first piston 30241 to be pulled by the connecting rod and move upward along the second direction. The active gap h2 between the first piston 30241 and the sliding valve 3023 is eliminated. At this time, the first connecting rod 30244 is in a vertical direction, and the exhaust rocker arm 305 pad 3051 presses the sliding valve 3023. The slide valve 3023 presses the first piston 30241, which transmits force to the valve bridge body 3022 through the first connecting rod 30244, opening the exhaust valve. Since there is no gap between the slide valve 3023 and the first piston 30241 to compensate for the lift caused by the brake cam, the exhaust valve opens according to the brake valve lift, realizing exhaust braking. Figure 17 shown.

[0106] The first reset member 3025 and the second reset member 3026 may be springs, but are not limited to springs. For example, they may also be torsion springs. Any structure that can provide a reset force for the chute 3023 and the piston-connecting rod assembly 3024 may be understood as the first reset member 3025 and the second reset member 3026.

[0107] In the embodiment of the present invention, the size of the valve clearance can be adjusted by changing the size specifications and material of the first restoring member 3025 and the second restoring member 3026 .

[0108] See also Figure 18 , the figure discloses an exhaust braking method, which is based on Figure 16 and Figure 17 The exhaust brake system shown in FIG. 1 includes:

[0109] Step S1: Obtaining engine operating parameters, wherein the operating parameters include gear information and / or throttle opening information. When the gear is unchanged, a throttle opening of zero can be understood as the engine switching to a braking state; or when the gear is lowered, it can be understood as the engine switching to a braking state.

[0110] Step S2: Compare operating parameters to see if they meet preset requirements. Preset requirements include the gear being unchanged and the throttle opening being zero, and / or the gear being downgraded. As described above, if the gear is unchanged and the throttle opening is zero, then engine braking is determined to be necessary; otherwise, engine braking is determined not to be necessary. If the gear is downgraded, then engine braking is determined to be necessary; otherwise, engine braking is determined not to be necessary.

[0111] If the preset requirements are met, it is determined that the engine needs to be switched to the braking state, and step S3 is entered, and the solenoid valve is energized; if the preset requirements are not met, it is determined that the engine needs to be switched to the positive power state, and step S4 is entered, and the solenoid valve is de-energized.

[0112] As can be seen from the above description, the exhaust braking method of the present invention has a simple control logic and can switch between the engine's positive power state and the braking state by simply controlling the power on / off of the solenoid valve.

[0113] In the description of the embodiments of the present invention, unless otherwise specified, “ / ” means or, for example, A / B can mean A or B; “and / or” in this article is merely a way to describe the association relationship of associated objects, indicating that three relationships may exist, for example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone.

[0114] It should be noted that, for ease of description, only the parts related to the invention are shown in the drawings. In the absence of conflict, the embodiments and features of the embodiments of the present invention can be combined with each other.

[0115] The above description is only a preferred embodiment of the present invention and an illustration of the technical principles used, and is not intended to limit the present invention. For those skilled in the art, the present invention can be modified and varied in various ways. The scope of the invention involved in the present invention is not limited to the technical solutions formed by a specific combination of the above-mentioned technical features, but should also cover other technical solutions formed by any combination of the above-mentioned technical features or their equivalent features without departing from the above-mentioned inventive concept. For example, the above-mentioned features are replaced with the technical features with similar functions disclosed in the present invention (but not limited to) by each other to form a technical solution.

Claims

1. A valve bridge, characterized in that: The camshaft assembly comprises a valve bridge body, a sliding valve, a piston-connecting rod assembly, a first restoring member and a second restoring member, wherein a brake valve clearance is provided between the sliding valve and the valve bridge body; the sliding valve is slidably arranged in the middle of the valve bridge body and is configured with an oil inlet state and an oil drain state; the piston-connecting rod assembly is located between the sliding valve and the valve bridge body and is configured with a locked state and an unlocked state; the first restoring member is used to drive the sliding valve to reset; the second restoring member is used to drive the piston-connecting rod assembly to reset; when the sliding valve is in the oil inlet state, the pressure oil between the sliding valve and the valve bridge body pushes the piston-connecting rod assembly to the unlocked state, and the brake valve clearance is maintained; when the sliding valve is in the oil drain state, the first restoring member drives the sliding valve to reset, and the second restoring member drives the piston-connecting rod assembly to reset to the locked state, and the brake valve clearance is eliminated; The valve bridge body includes a sliding cavity, a first guide groove, a second guide groove, a first port, and a first oil passage, wherein the sliding cavity is located in the middle of the valve bridge body and is used to accommodate the movement of the sliding valve; the first guide groove and the second guide groove are used to accommodate the movement of the piston connecting rod assembly; the first port is located on the inner wall of the sliding cavity and is used to communicate with the sliding valve; the first oil passage communicates with the first guide groove and the first port; The first oil channel is arranged on the inner wall of the valve bridge body; the first port is a straight hole extending along the first direction, and the first oil channel is a straight hole along the second direction; the first oil channel is located at one end of the end face of the valve bridge body and is provided with a first seal, and the first seal is used to seal the first oil channel; the first port is located at one end of the peripheral surface of the valve bridge body and is provided with a second seal, and the second seal is used to seal the first port; the first direction is perpendicular to the second direction.

2. The valve bridge according to claim 1, wherein: The sliding cavity is provided with a first retaining groove for limiting the sliding valve from being separated from the valve bridge body, and a first retaining ring is provided in the first retaining groove.

3. The valve bridge according to claim 2, wherein: The spool valve is movable between a first position and a second position, wherein a distance between the first position and the second position in a second direction is equal to a brake valve clearance; When the sliding valve moves to the first position, the first retaining ring limits the sliding valve from continuing to move to prevent the sliding valve from separating from the valve bridge body; when the sliding valve remains in the first position, the brake valve clearance is eliminated; the sliding valve can move between the first position and the second position, and the brake valve clearance is maintained.

4. The valve bridge according to claim 1, wherein: The second guide groove is provided with a second retaining groove for limiting the piston connecting rod assembly from being separated from the valve bridge body, and a second retaining ring is provided in the second retaining groove.

5. The valve bridge according to claim 4, characterized in that When the second restoring member is located in the second guide groove, a gasket is further provided between the second retaining ring and the second restoring member.

6. The valve bridge according to claim 1, wherein: The sliding valve includes a second port, a third port, and a second oil passage, wherein the second port is connected to the third port through the second oil passage. When oil is admitted to the second port, the pressure oil flows to the third port through the second oil passage via the second port; when oil is discharged from the second port, the pressure oil flows to the second port through the second oil passage via the third port.

7. The valve bridge according to claim 6, characterized in that The second oil passage is arranged along a housing wall of the slide valve.

8. The valve bridge according to claim 6, wherein: There are four second oil passages, and one second oil passage corresponds to one third port.

9. The valve bridge according to claim 6, wherein: The second oil passage is communicated with the second port through the third oil passage.

10. The valve bridge according to claim 9, wherein: The third oil passage is arranged obliquely.

11. The valve bridge according to claim 9, wherein: The second port is located at the top of the slide valve, and a diameter of the second port is larger than a diameter of the third oil passage.

12. The valve bridge according to claim 6, wherein: An annular oil groove is provided on the circumferential surface of the sliding valve, the third port is located at the bottom of the annular oil groove, and the width of the annular oil groove is greater than the diameter of the third port.

13. The valve bridge according to claim 1, wherein: The sliding valve is further provided with a compression groove for accommodating the first restoring member. One end of the first restoring member abuts against the compression groove, and the other end of the first restoring member abuts against the bottom wall of the sliding cavity.

14. The valve bridge according to claim 1, wherein: One end of the sliding valve close to the piston-connecting rod assembly is provided with a third guide groove for accommodating the actuator of the piston-connecting rod assembly, and the actuator of the piston-connecting rod assembly is slidably provided in the third guide groove.

15. The valve bridge according to claim 14, wherein: The piston-connecting rod assembly includes a first piston, a second piston, a third piston, a first connecting rod, a second connecting rod and a third connecting rod, wherein the first end of the first connecting rod is rotatably connected to the first piston; the first end of the second connecting rod is rotatably connected to the second piston; the first end of the third connecting rod is rotatably connected to the third piston; the second end of the first connecting rod, the second end of the second connecting rod and the second end of the third connecting rod are all rotatably connected; the first piston is slidably disposed in the third guide groove, the second piston is slidably disposed in the first guide groove, and the third piston is slidably disposed in the second guide groove.

16. The valve bridge according to claim 15, wherein: The mutually cooperating parts among the first connecting rod, the second connecting rod, the third connecting rod, the first piston, the second piston and the third piston are provided with a rotating part or a rotating groove, so that the rotating part is inserted into the rotating groove and is rotatably connected through the corresponding rotating shaft.

17. A brake actuator, characterized in that: The invention comprises an exhaust rocker arm and a valve bridge, wherein the gasket of the exhaust rocker arm cooperates with the valve bridge, and the valve bridge is the valve bridge according to any one of claims 1 to 16.

18. An exhaust brake system, comprising a controller, a solenoid valve and a brake actuator, wherein the brake actuator is the brake actuator as claimed in claim 17; the controller controls the conduction state of the solenoid valve to achieve conduction or cutoff of the brake actuator and the engine oil supply, thereby switching the brake actuator between the brake valve clearance maintaining state and the elimination state.

19. An exhaust braking method, characterized in that: The exhaust braking method is based on the exhaust braking system according to claim 18, and the exhaust braking method includes: Obtain engine operating parameters; Compare whether the operating parameters meet the preset requirements; If the preset requirements are met, it is determined that the engine needs to be switched to the braking state, and the solenoid valve is energized; If the preset requirements are not met, it is determined that the engine needs to be switched to the positive power state and the solenoid valve is de-energized.

20. An engine, characterized in that: Comprising the exhaust brake system of claim 18.

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