Engine secondary compression release braking device, engine and vehicle

Abstract

The invention discloses an engine secondary compression release braking device, an engine and a vehicle. The engine secondary compression release braking device comprises an intake valve assembly; the air inlet cam comprises a base circle part, a first protruding position and a second protruding position. The air inlet cam drives the air inlet rocker arm to rotate, so that the second end of the air inlet rocker arm moves towards the air inlet valve assembly, and the engine is in an acting stroke in the process that the first protruding position abuts against the air inlet rocker arm; the executing mechanism is located between the second end of the air inlet rocker arm and the air inlet valve assembly and used for abutting against the air inlet valve assembly and driving an air inlet valve of the air inlet valve assembly to be opened. The driving mechanism is used for driving the executing mechanism to move relative to the second end of the air inlet rocker. In the power stroke of the engine, air is fed through the air inlet valve, the amount of air in the air cylinder in the second compression release process of the engine is guaranteed, and therefore the braking power of the engine is guaranteed; the temperature of gas entering the air cylinder is reduced through air intake of the air inlet valve, and therefore the thermal loads of an oil nozzle, the air inlet valve and an exhaust valve of the engine are reduced.

Description

Technical Field

[0001] The invention relates to the technical field of engine braking, and in particular to an engine secondary compression release braking device, an engine and a vehicle. Background Art

[0002] The principle of the engine's secondary compression release brake is to use the mechanical movement inside the engine to consume the vehicle's kinetic energy by controlling the engine's intake and exhaust processes, thereby achieving a braking effect. Specifically, when the engine brake is activated, the engine changes from a power output state to a power consumption state. Near the end of the compression stroke, the exhaust valve is opened, allowing the compressed gas to be discharged directly instead of pushing the piston to do work, thereby consuming the vehicle's kinetic energy.

[0003] The existing secondary compression release braking method of the engine opens the exhaust port during the power stroke of the engine and uses exhaust backflow to achieve air replenishment in the cylinder. However, since the temperature of the compressed gas at the exhaust valve is relatively high, the exhaust backflow method will increase the heat load in the cylinder and the intake and exhaust pipes, which can easily cause damage to the injector and reduce the reliability of the exhaust valve.

[0004] Therefore, how to provide an engine secondary compression release brake device to reduce the intake temperature during the engine power stroke, so as to reduce the thermal load of the engine's cylinder, intake pipe and exhaust pipe. Summary of the invention

[0005] In view of this, the present invention provides an engine secondary compression release brake device to reduce the intake temperature during the engine power stroke to reduce the heat load of the engine cylinder, intake pipe and exhaust pipe. In addition, the present invention also provides an engine and a vehicle having the above engine secondary compression release brake device.

[0006] To achieve the above object, the present invention provides the following technical solutions:

[0007] An engine secondary compression release brake device, comprising:

[0008] Intake valve assembly;

[0009] An intake cam, the intake cam comprising a base circle portion, a first raised portion disposed on the base circle portion, and a second raised portion connected to the base circle portion;

[0010] An intake rocker arm, wherein the intake cam is used to drive the intake rocker arm to rotate so that the second end of the intake rocker arm moves toward the intake valve assembly, and the first protrusion is located within the range where the intake cam and the intake rocker arm abut against each other when the engine is in a power stroke;

[0011] An actuator, the actuator is located between the second end of the intake rocker arm and the intake valve assembly, and is used to abut against the intake valve assembly to drive the intake valve of the intake valve assembly to open; the distance between the actuator and the second end of the intake rocker arm is adjustable;

[0012] A driving mechanism is used to drive the actuator to move relative to the second end of the intake rocker arm.

[0013] Preferably, in the above-mentioned engine secondary compression release brake device, the intake valve assembly includes:

[0014] An intake valve bridge, wherein the actuator is located between the intake valve bridge and the second end of the intake rocker arm, and the actuator is used to drive the intake valve bridge;

[0015] Intake valve, the intake valve bridge is fixedly connected to the intake valve, and the intake valve bridge connects at least two intake valves.

[0016] Preferably, in the above-mentioned engine secondary compression release brake device, the actuator is installed at the second end of the intake rocker arm, and the actuator can move toward the intake valve assembly relative to the intake rocker arm.

[0017] Preferably, in the above-mentioned engine secondary compression release brake device, the second end of the intake rocker arm has a receiving groove, the actuator is installed in the receiving groove so as to be movable along the receiving groove, and the moving direction of the actuator is the axial direction of the intake valve of the intake valve assembly.

[0018] Preferably, in the above-mentioned engine secondary compression release brake device, the actuator includes:

[0019] An execution body, the execution body is movably installed in the receiving groove;

[0020] The elephant foot is hinged to a side of the actuator body close to the intake valve assembly, and the elephant foot is used to fit with the intake valve bridge.

[0021] Preferably, in the above-mentioned engine secondary compression release brake device, the end of the actuator body close to the elephant foot has a spherical surface, and the elephant foot has a ball groove for engaging with the spherical surface.

[0022] Preferably, in the above-mentioned engine secondary compression release brake device, a reset spring for resetting the actuator body is provided between the actuator body and the bottom of the accommodating groove.

[0023] Preferably, in the above-mentioned engine secondary compression release brake device, the driving mechanism comprises:

[0024] A brake oil circuit, the brake oil circuit comprising an oil inlet pipeline and an oil outlet pipeline, the output end of the oil inlet pipeline is communicated with the accommodating tank, and the input end of the oil outlet pipeline is communicated with the accommodating tank;

[0025] A first solenoid valve, the first solenoid valve is used to control the on-off of the oil inlet pipeline;

[0026] The second solenoid valve is used to control the on-off of the oil outlet pipeline.

[0027] Preferably, in the above-mentioned engine secondary compression release brake device, when the driving mechanism is in the first working state, the distance between the actuator and the intake valve assembly is L1; when the driving mechanism is in the second working state, the distance between the actuator and the intake valve assembly is L2, and L1 is greater than L2;

[0028] Along the radial direction of the intake cam, the protrusion size of the first protrusion relative to the base circle portion is greater than L2 and smaller than L1;

[0029] Along the radial direction of the intake cam, a dimension of the second protrusion relative to the base circle portion is greater than L1.

[0030] An engine comprises an engine secondary compression release brake device, wherein the engine secondary compression release brake device is any one of the engine secondary compression release brake devices described above.

[0031] A vehicle comprises an engine, wherein the engine is the engine described above.

[0032] The embodiment of the present invention discloses a secondary compression release brake device for an engine, which uses a driving mechanism to change the position of an actuator relative to an intake valve assembly, and sets a first raised position on the intake cam, so that during the operation of the engine, the crankshaft rotates to the power stroke state, the first raised position drives the intake rocker arm to rotate, the actuator drives the intake valve to open, and the intake valve is used to replenish air into the cylinder, so that the engine performs a second compression release. In the embodiment of the present application, the engine uses the intake valve to intake air during the power stroke, which ensures the amount of gas in the cylinder during the second compression release of the engine, thereby ensuring the braking power of the engine; in addition, the intake through the intake valve can also reduce the temperature of the gas entering the cylinder, thereby reducing the heat load of the engine's fuel injector, intake valve and exhaust valve. 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 drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0034] Figure 1 The valve lift curve of the secondary compression release braking mode of the engine disclosed in the existing embodiment;

[0035] Figure 2 is a valve lift curve of the secondary compression release braking mode of the engine disclosed in an embodiment of the present invention;

[0036] Figure 3 It is a structural schematic diagram of the engine secondary compression release brake device disclosed in an embodiment of the present invention in the engine brake closed state;

[0037] Figure 4 It is a structural schematic diagram of the engine secondary compression release brake device disclosed in an embodiment of the present invention in the engine brake on state;

[0038] Figure 5 It is a structural schematic diagram of the actuator disclosed in the embodiment of the present invention;

[0039] Figure 6 It is a schematic diagram of the structure of the intake cam disclosed in an embodiment of the present invention. DETAILED DESCRIPTION

[0040] The invention discloses an engine secondary compression release brake device to reduce the intake temperature during the engine power stroke to reduce the heat load of the engine cylinder, intake pipe and exhaust pipe. In addition, the invention also discloses an engine and a vehicle having the engine secondary compression release brake device.

[0041] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0042] In the following, the terms "first" and "second" are used for descriptive purposes only and are not to be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features.

[0043] like Figure 1 As shown, the secondary compression release braking method of the engine in some embodiments is: the exhaust main lift during positive power of the engine disappears in advance, the intake main lift is retained, and the opening and closing of a single exhaust valve in the entire stroke of the engine is controlled by an additional exhaust cam and exhaust rocker arm mechanism, wherein the opening position of the exhaust valve includes: opening near the top dead center of the piston to release high-pressure gas; opening in the expansion stroke to allow exhaust gas to flow back into the cylinder to provide charging for the second compression release.

[0044] Specifically, Figure 1 The braking process of the engine: when the crankshaft angle is near 0°, the piston moves up to near the top dead center (that is, the end of the compression stroke). At this time, the piston completes the compression of the air in the cylinder, and the brake exhaust lift is large, that is, the exhaust valve is in an open state, and the air compressed by the piston is discharged through the exhaust valve, thereby completing the first compression release.

[0045] As the crankshaft angle increases, the piston begins to move downward, and the engine enters the power stroke (also known as the expansion stroke). During this process, the intake valve is closed, and when the crankshaft angle is around 108°, the exhaust valve is open to allow exhaust gas to flow back into the cylinder until the crankshaft rotates to around 180°. The gas flowing back into the cylinder provides charge for the second compression and release of the engine. It should be noted that since the engine opens the exhaust valve at the end of the compression stroke, the compressed air is discharged from the exhaust valve, so that the compressed gas does not push the piston to work, that is, the first compression and release of the engine is completed.

[0046] As the crankshaft angle continues to increase, the piston begins to move upward and the engine enters the exhaust stroke. During this process, the intake valve and exhaust valve are in a closed state, and the piston compresses the gas that flows back into the cylinder. When the piston moves upward to near the top dead center, the exhaust valve opens, and the gas compressed by the piston is discharged through the exhaust valve. As the gas compressed by the piston is discharged again, the second compression and release of the engine is completed.

[0047] As the crankshaft angle increases further, the piston begins to move downward, and the engine enters the intake stroke (also called the suction stroke). During this process, the intake valve is in the open state, the exhaust valve is in the closed state, and fresh air enters the cylinder through the intake valve, completing the engine's intake process.

[0048] As the crankshaft angle increases, the piston begins to move upward and the engine enters the compression stroke. During this process, the intake valve and exhaust valve are both closed, and the fresh air in the cylinder is compressed until the piston moves upward to the top dead center. The engine enters the end of the compression stroke, and the exhaust valve opens to release the compressed gas.

[0049] By repeating the above operations, the vehicle's kinetic energy is continuously released, thereby achieving the effect of deceleration.

[0050] Combined with the working process of the above engine, it can be known that during the secondary compression release braking process of the above engine, the second cylinder air intake is achieved by exhaust backflow. Since the temperature of the compressed gas at the exhaust valve is relatively high, the exhaust backflow method will increase the heat load in the cylinder and the intake and exhaust pipes, which is easy to cause damage to the injector; and the exhaust valve is subjected to a high heat load, which will reduce the reliability of the exhaust valve.

[0051] In addition, during the exhaust stroke of the engine, when the piston moves to the top dead center, the exhaust valve opens to release the compressed gas, and the intake valve opens to allow fresh air to enter through the intake valve, that is, the intake valve and the exhaust valve are opened overlappingly, which can easily cause the high-pressure and high-temperature gas at the exhaust valve to flow back into the intake pipe, causing damage to components such as the intake heating grille, the intake pressure and temperature sensor, and the intake throttle valve.

[0052] Based on the above problems, Figure 2 As shown, the embodiment of the present application discloses a secondary compression release braking method for an engine, which opens the intake valve and closes the exhaust valve during the power stroke of the engine, thereby intakes air through the intake valve to achieve air replenishment in the cylinder. Compared with backflow of gas through the exhaust valve, this method can achieve lower temperature gas entering the cylinder, thereby reducing the impact of heat load.

[0053] Specifically, Figure 2 The braking process of the engine is as follows: when the crankshaft angle is near 0°, the piston moves up to near the top dead center (that is, the end of the compression stroke). At this time, the piston completes the compression of the air in the cylinder, and the brake exhaust lift is large, that is, the exhaust valve is in an open state, and the air compressed by the piston is discharged through the exhaust valve, thereby completing the first compression release.

[0054] As the crankshaft angle increases, the piston begins to move downward, and the engine enters the power stroke (also known as the expansion stroke). During this process, the intake valve opens and the exhaust valve closes, allowing fresh air from the outside to enter the cylinder of the engine to provide charge for the second compression and release of the engine. It should be noted that since the exhaust valve is opened at the end of the compression stroke, the compressed air is discharged from the exhaust valve, so that the compressed gas does not push the piston to work, that is, the first compression and release of the engine is completed.

[0055] As the crankshaft angle continues to increase, the piston begins to move upward and the engine enters the exhaust stroke. During this process, the intake valve and exhaust valve are in a closed state, and the piston compresses the gas in the cylinder. When the piston moves upward to near the top dead center, the exhaust valve opens, and the gas compressed by the piston is discharged through the exhaust valve. As the gas compressed by the piston is discharged again, the second compression and release of the engine is completed.

[0056] As the crankshaft angle increases further, the piston begins to move downward, and the engine enters the intake stroke (also called the suction stroke). During this process, the intake valve is in the open state, the exhaust valve is in the closed state, and fresh air enters the cylinder through the intake valve, completing the engine's intake process.

[0057] As the crankshaft angle increases, the piston begins to move upward and the engine enters the compression stroke. During this process, the intake valve and exhaust valve are both closed, and the fresh air in the cylinder is compressed until the piston moves upward to the top dead center. The engine enters the end of the compression stroke, and the exhaust valve opens to release the compressed gas.

[0058] By repeating the above operations, the vehicle's kinetic energy is continuously released, thereby achieving the effect of deceleration.

[0059] Combination Figure 2 It can be seen from the braking process that in the embodiment of the present application, the engine uses the intake valve to intake air during the power stroke, thereby ensuring the amount of gas in the cylinder during the second compression and release process of the engine, thereby ensuring the braking power of the engine; in addition, intake air through the intake valve can also reduce the temperature of the gas entering the cylinder, thereby reducing the heat load on the engine's fuel injector, intake valve and exhaust valve.

[0060] The following describes a device for realizing air intake by using an intake valve during the power stroke of the engine.

[0061] like Figure 3 and Figure 4 As shown, the engine secondary compression release brake device disclosed in the embodiment of the present application includes: an intake valve assembly 1, an intake rocker arm 3, an intake cam 4, a drive mechanism 5 and an actuator 2. The intake valve assembly 1 includes an intake valve 11 and an intake valve bridge 12.

[0062] There are two intake valves 11 , and the intake valve bridge 12 is fixedly connected to the two intake valves 11 .

[0063] The intake cam 4 abuts against the first end of the intake rocker arm 3 to drive the intake rocker arm 3 to rotate. The second end of the intake rocker arm 3 is used to abut against the intake valve bridge 12 to drive the intake valve 11 to control the opening and closing of the intake passage of the cylinder. In some embodiments, the intake cam 4 can directly contact and abut against the intake rocker arm 3, or can abut against the intake rocker arm 3 through a push column. During the rotation of the intake cam 4, the push column is driven to move in the vertical direction, and the push column drives the intake rocker arm 3 to rotate.

[0064] The second end of the intake rocker arm 3 disclosed in the embodiment of the present application is provided with an actuator 2, and the actuator 2 is retractable relative to the intake rocker arm 3 to change the distance between the second end of the intake rocker arm 3 and the intake valve bridge 12, specifically, to change the distance between the actuator 2 and the intake valve bridge 12. In an optional embodiment, the actuator 2 can also be installed on the intake valve assembly 1, and the actuator 2 can move toward the intake rocker arm 3 relative to the intake valve assembly 1. Exemplarily, the actuator 2 is installed on the intake valve bridge 12.

[0065] The driving mechanism 5 is connected to the actuator 2 and is used to control the actuator 2 to extend and retract relative to the intake rocker arm 3. It should be noted that the driving mechanism 5 has two working states, wherein when the driving mechanism 5 is in the first working state, the distance between the actuator 2 and the intake valve bridge 12 is the initial distance, which is recorded as L1 in this application document; when the driving mechanism 5 is in the second working state, the distance between the actuator 2 and the intake valve bridge 12 changes, specifically, the actuator 2 moves toward the intake valve bridge 12, so that the distance between the actuator 2 and the intake valve bridge 12 is reduced, and when the driving mechanism 5 is in the second working state, the distance between the actuator 2 and the intake valve bridge 12 is recorded as L2 in this application document.

[0066] It should be noted that, in the present application document, after the engine is turned on for braking, the drive mechanism 5 is in the second working state; and after the engine is turned off for braking, the drive mechanism 5 is in the first working state.

[0067] When the engine starts braking, the driving mechanism 5 drives the actuator 2 to move relative to the intake rocker arm 3 close to the intake valve bridge 12 to reduce the distance between the second end of the intake rocker arm 3 and the intake valve bridge 12. When the engine is in the power stroke, the intake cam 4 rotates to the first raised position 41 of the intake cam 4, and the intake cam 4 drives the intake rocker arm 3 to rotate, so that the second end of the intake rocker arm 3 abuts against the intake valve bridge 12, and drives the intake valve bridge 12 to apply force to the two intake valves at the same time, so that the two intake valves 11 are opened, and the engine charges air into the cylinder through the intake valve 11.

[0068] It can be understood that when the first protrusion 41 of the intake cam 4 in the embodiment of the present application abuts against the intake rocker arm 3, the engine is in a power stroke.

[0069] When the engine is turned off and braked, the driving mechanism 5 drives the actuator 2 to move relative to the intake rocker arm 3 in a direction away from the intake valve bridge 12, so that there is a gap between the actuator 2 and the intake valve bridge 12. It should be noted that the size of the gap needs to meet the following requirements: when the first protrusion 41 of the intake cam 4 abuts against the intake rocker arm 3, the actuator 2 will not abut against the intake valve bridge 12, that is, the intake valve 11 will not open, so as to ensure the normal operation of the engine.

[0070] The engine secondary compression release brake device in the embodiment of the present application uses a driving mechanism 5 to change the position of the actuator 2 relative to the intake valve bridge 12, and a first raised position 41 is set on the intake cam 4, so that when the engine is running in the brake-on state, the crankshaft rotates to the power stroke state, and the first raised position 41 drives the intake rocker arm 3, so that the actuator 2 and the intake valve bridge 12 are offset, and then the intake valve 11 is opened, and the intake valve 11 is used to replenish air into the cylinder, so that the engine performs a second compression release. In the embodiment of the present application, the engine uses the intake valve to intake air during the power stroke, which ensures the amount of gas in the cylinder during the second compression and release of the engine, thereby ensuring the braking power of the engine; in addition, the intake through the intake valve can also reduce the temperature of the gas entering the cylinder, thereby reducing the heat load of the engine's fuel injector, intake valve and exhaust valve.

[0071] In some embodiments, the second end of the intake rocker arm 3 has a receiving groove, and the actuator 2 is telescopically installed in the receiving groove. Specifically, the telescopic direction of the actuator 2 is the axial direction of the intake valve 11 of the intake valve assembly 1. The driving mechanism 5 includes but is not limited to a fluid system, and when the engine is in a power stroke, the fluid system is connected, and the oil drives the actuator 2 in the receiving groove to move toward the intake valve bridge 12 to reduce the distance between the actuator 2 and the intake valve bridge 12.

[0072] The structure of the hydraulic system can be set according to different needs, as long as it can realize the driving of the actuator 2. Exemplarily, the driving mechanism 5 includes: a brake oil circuit, a first solenoid valve and a second solenoid valve. Among them, the brake oil circuit includes an oil inlet pipeline and an oil outlet pipeline, the output end of the oil inlet pipeline is connected to the receiving tank, and the input end of the oil outlet pipeline is connected to the receiving tank. The specific structure of the oil inlet pipeline and the oil outlet pipeline can be set according to different needs. The first solenoid valve is used to control the on-off of the oil inlet pipeline, and the second solenoid valve is used to control the on-off of the oil outlet pipeline. When the driving mechanism 5 is in the first working state, the first solenoid valve closes the oil inlet pipeline, the second solenoid valve conducts the oil outlet pipeline, and the actuator 2 does not move in the receiving tank; when the driving mechanism 5 is in the second working state, the first solenoid valve conducts the oil inlet pipeline, the second solenoid valve closes the oil outlet pipeline, and the actuator 2 moves in the receiving tank.

[0073] In other optional embodiments, the driving mechanism 5 may also be an electromagnetic structure, and the position of the actuator 2 is changed by the gain and loss of electricity of the electromagnetic structure. Exemplarily, the driving mechanism 5 is a magnetic attraction structure, and the actuator 2 is a magnetic attraction metal part.

[0074] In some embodiments, a reset spring is provided between the actuator 2 and the bottom of the receiving groove to facilitate resetting the actuator 2 after movement.

[0075] Combination Figures 3 to 5As shown, the actuator 2 in the embodiment of the present application includes an actuator body 21 and an elephant foot 22 .

[0076] The actuator body 21 includes but is not limited to a piston, and is movably installed in the receiving groove of the intake rocker arm 3. The actuator body 21 is hinged with an elephant foot 22 on one side close to the intake valve bridge 12. The elephant foot 22 is hinged to the actuator body 21, so as to ensure that when the intake valve is driven to open and the intake rocker arm 3 rotates, the lower surface of the elephant foot 22 is always parallel to and in contact with the intake valve bridge 12.

[0077] One end of the execution body 21 close to the elephant foot 22 is a spherical surface, and the elephant foot 22 has a ball groove that cooperates with the spherical surface. The elephant foot 22 and the execution body 21 are hingedly connected through the cooperation of the spherical surface and the ball groove.

[0078] It should be noted that the installation method of the actuator 2 on the intake valve bridge 12 can refer to the installation method of the actuator 2 on the intake rocker arm 3, which is not specifically limited here.

[0079] Combination Figure 3 , Figure 4 and Figure 6 As shown, the intake cam 4 in the embodiment of the present application has a first convex position 41 , a second convex position 42 and a base circle portion 43 .

[0080] Among them, the base circle portion 43 and the second raised position 42 are set as the main structure of the intake cam 4, the first raised position 41 is set on the base circle portion 43, the first raised position 41 protrudes from the base circle portion 43, and the second raised position 42 is eccentrically arranged relative to the rotation center of the intake cam 4, that is, the second raised position 42 protrudes from the base circle portion 43.

[0081] When the base circle portion 43 abuts against the intake rocker arm 3, the intake valve 11 is closed; when the intake cam rotates to the second raised position 42 and abuts against the intake rocker arm 3 under the driving action, the intake rocker arm 3 is driven to rotate, so that the intake rocker arm 3 opens the intake valve 11.

[0082] It should be noted that, along the radial direction of the intake cam 4, the protruding dimension of the first raised position 41 relative to the base circle 43 is larger than L2 in the above embodiment (the distance between the actuator 2 and the intake valve bridge 12 when the drive mechanism 5 is in the second working state), so that when the intake cam 4 rotates to the point where the first raised position 41 abuts against the intake rocker arm 3, the actuator 2 can drive the intake valve bridge 12 to move, so as to open the intake valve 11. And the protruding dimension of the first raised position 41 relative to the base circle 43 is smaller than L1 (the distance between the actuator 2 and the intake valve bridge 12 when the drive mechanism 5 is in the first working state), so as to ensure that when the first raised position 41 of the intake cam 4 abuts against the intake rocker arm 3 when the engine is in the off-brake state, the actuator 2 will not abut against the intake valve bridge 12, that is, the intake valve 11 will not open, so as to ensure the normal operation of the engine.

[0083] Along the radial direction of the intake cam 4 , the protrusion of the second raised position 42 relative to the base circle 43 is greater than L1 to ensure that when the second raised position 42 abuts against the intake rocker arm 3 , the actuator 2 can abut against the intake valve bridge 12 to open the intake valve 11 .

[0084] In some embodiments, the size of the first protrusion 41 along the circumferential direction of the intake cam 4 can be set according to the amount of air replenishment required in the power stroke of the engine, which is not specifically limited here and is within the protection range.

[0085] Combined with the contents disclosed in the above embodiments, it can be known that the engine secondary compression release brake device in the embodiment of the present application cancels the in-cylinder intake form of exhaust backflow, and still uses the intake valve 11 to replenish the gas charge in the cylinder, thereby reducing the heat load in the cylinder and the intake and exhaust pipes. The main intake lift is retained, and the second intake also opens multiple intake valves, thus avoiding the problem of valve bridge tilting and falling off when opening a single intake valve, and its maximum lift can also be flexibly adjusted, thus increasing the gas charge in the cylinder, and obtaining a higher maximum cylinder pressure, further improving the engine's braking power.

[0086] In addition, an engine is also protected in an embodiment of the present application, including an engine secondary compression-release brake device, and the engine secondary compression-release brake device is the engine secondary compression-release brake device disclosed in the above embodiment. Therefore, the engine having the engine secondary compression-release brake device also has all the above-mentioned technical effects, which will not be repeated here one by one.

[0087] In addition, the present application protects a vehicle including an engine, and the engine is the engine disclosed in the above-mentioned embodiment, therefore, the vehicle having the engine also has all the above-mentioned technical effects.

[0088] The various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other.

[0089] The above description of the disclosed embodiments enables one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. An engine secondary compression release brake device, characterized in that: include: Intake valve assembly (1); An intake cam (4), the intake cam (1) comprising a base circle portion (43), a first raised portion (41) arranged on the base circle portion (43), and a second raised portion (42) connected to the base circle portion (43); An intake rocker arm (3), wherein the intake cam (4) is used to drive the intake rocker arm (3) to rotate so that the second end of the intake rocker arm (3) moves toward the intake valve assembly (1), and the first protrusion (41) is located within a range where the intake cam (4) and the intake rocker arm (3) abut against each other when the engine is in a power stroke; an actuator (2), the actuator (2) being located between the second end of the intake rocker arm (3) and the intake valve assembly (1), and being used to abut against the intake valve assembly (1) to drive the intake valve of the intake valve assembly (1) to open; the distance between the actuator (2) and the second end of the intake rocker arm (3) is adjustable; A driving mechanism (5), wherein the driving mechanism (5) is used to drive the actuator (2) to move relative to the second end of the intake rocker arm (3).

2. The engine secondary compression release brake device according to claim 1, characterized in that: The intake valve assembly (1) comprises: An intake valve bridge (12), wherein the actuator (2) is located between the intake valve bridge (2) and the second end of the intake rocker arm (3), and the actuator (2) is used to drive the intake valve bridge (12); An intake valve (11), wherein the intake valve bridge (12) is fixedly connected to the intake valve (11), and the intake valve bridge (12) connects at least two of the intake valves (11).

3. The engine secondary compression release brake device according to claim 2, characterized in that: The actuator (2) is mounted on the second end of the intake rocker arm (3), and the actuator (2) can move toward the intake valve assembly (1) relative to the intake rocker arm (3).

4. The engine secondary compression release brake device according to claim 3, characterized in that: The second end of the intake rocker arm (3) has a receiving groove, and the actuator (2) is installed in the receiving groove so as to be movable along the receiving groove, and the moving direction of the actuator (2) is the axial direction of the intake valve (11) of the intake valve assembly (1).

5. The engine secondary compression release brake device according to claim 4, characterized in that: The actuator (2) comprises: An execution body (21), the execution body (21) being movably installed in the receiving groove; An elephant foot (22), the elephant foot (22) being hinged to a side of the actuator body (21) close to the intake valve assembly (1), and the elephant foot (22) being used to fit with the intake valve bridge (12).

6. The engine secondary compression release brake device according to claim 5, characterized in that: One end of the execution body (21) close to the elephant foot (22) has a spherical surface, and the elephant foot (22) has a ball groove for engaging with the spherical surface.

7. The engine secondary compression release brake device according to claim 5, characterized in that: A reset spring for resetting the execution body (21) is arranged between the execution body (21) and the bottom of the accommodating groove.

8. The engine secondary compression release brake device according to claim 4, characterized in that: The driving mechanism (5) comprises: A brake oil circuit, the brake oil circuit comprising an oil inlet pipeline and an oil outlet pipeline, the output end of the oil inlet pipeline is communicated with the accommodating tank, and the input end of the oil outlet pipeline is communicated with the accommodating tank; A first solenoid valve, the first solenoid valve is used to control the on-off of the oil inlet pipeline; The second solenoid valve is used to control the on-off of the oil outlet pipeline.

9. The engine secondary compression release brake device according to any one of claims 1 to 8, characterized in that: When the driving mechanism (5) is in a first working state, the distance between the actuator (2) and the intake valve assembly (1) is L1; when the driving mechanism (5) is in a second working state, the distance between the actuator (2) and the intake valve assembly (1) is L2, and L1 is greater than L2; Along the radial direction of the intake cam (4), the protrusion dimension of the first protrusion (41) relative to the base circular portion (43) is greater than L2 and smaller than L1; Along the radial direction of the intake cam (4), the protrusion dimension of the second protruding position (42) relative to the base circular portion (43) is greater than L1.

10. An engine, comprising an engine secondary compression release brake device, characterized in that: The engine secondary compression release brake device is the engine secondary compression release brake device as claimed in any one of claims 1 to 9.

11. A vehicle comprising an engine, characterized in that: The engine is the engine as claimed in claim 10.

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