An engine secondary compression release brake device, an engine and a vehicle

Abstract

This invention discloses an engine secondary compression release braking device, an engine, and a vehicle, comprising: an intake valve assembly; an intake cam including a base circle, a first convex portion, and a second convex portion; an intake rocker arm, the intake cam driving the intake rocker arm to rotate, causing the second end of the intake rocker arm to move toward the intake valve assembly, the engine being in its power stroke during the first convex portion abutting against the intake rocker arm; an actuator located between the second end of the intake rocker arm and the intake valve assembly, used to abut against the intake valve assembly and drive the intake valve of the intake valve assembly to open; and a drive mechanism used to drive the actuator to move relative to the second end of the intake rocker arm. During the engine's power stroke, the intake valve allows air to enter, ensuring the amount of gas in the cylinder during the engine's secondary compression release, thereby ensuring the engine's braking power; the intake valve also reduces the temperature of the gas entering the cylinder, thereby reducing the thermal load on the engine's fuel injectors, intake valves, and exhaust valves.

Description

Technical Field

[0001] This invention relates to the technical field of engine braking, and particularly to an engine secondary compression release braking device, an engine, and a vehicle. Background Technology

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

[0003] Existing engine secondary compression release braking methods involve opening the exhaust port during the engine's power stroke and using exhaust backflow to replenish air into the cylinder. However, because the temperature of the compressed gas at the exhaust valve is relatively high, exhaust backflow increases the thermal load on the cylinder, intake manifold, and exhaust manifold, which can easily damage the fuel injectors and reduce the reliability of the exhaust valve.

[0004] Therefore, it is necessary to provide a secondary compression release braking device for an engine to reduce the intake air temperature during the engine's power stroke, thereby reducing the thermal load on the engine's cylinders, intake manifold, and exhaust manifold. Summary of the Invention

[0005] In view of this, the present invention provides an engine secondary compression release braking device to reduce the intake air temperature during the engine's power stroke, thereby reducing the thermal load on the engine's cylinders, intake manifold, and exhaust manifold. Furthermore, the present invention also provides an engine and a vehicle incorporating the aforementioned engine secondary compression release braking device.

[0006] To achieve the above objectives, the present invention provides the following technical solution:

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

[0008] Intake valve assembly;

[0009] An intake cam, the intake cam including a base circle portion, a first protrusion disposed on the base circle portion and a second protrusion 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 during the engine's power stroke;

[0011] An 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 drive mechanism for driving the actuator to move relative to the second end of the intake rocker arm.

[0013] Preferably, in the above-mentioned engine secondary compression release braking 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] An intake valve, wherein 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-described engine secondary compression release braking device, the actuator is mounted on the second end of the intake rocker arm, and the actuator is movable relative to the intake rocker arm toward the intake valve assembly.

[0017] Preferably, in the above-mentioned engine secondary compression release braking device, the second end of the intake rocker arm has a receiving groove, the actuator is movably mounted in the receiving groove 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 braking device, the actuator includes:

[0019] An execution body is movably installed within the receiving slot;

[0020] The elephant foot is hinged to the side of the actuator body near the intake valve assembly and is used to fit against the intake valve bridge.

[0021] Preferably, in the above-described engine secondary compression release braking device, the end of the actuator near 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 braking device, a reset spring for resetting the actuator is provided between the actuator body and the bottom of the receiving groove.

[0023] Preferably, in the above-mentioned engine secondary compression release braking device, the drive mechanism includes:

[0024] The brake fluid circuit includes an inlet pipe and an outlet pipe, the output end of the inlet pipe is connected to the receiving groove, and the input end of the outlet pipe is connected to the receiving groove.

[0025] The first solenoid valve is used to control the opening and closing of the oil inlet pipeline;

[0026] The second solenoid valve is used to control the opening and closing of the oil outlet pipeline.

[0027] Preferably, in the above-mentioned engine secondary compression release braking device, when the drive mechanism is in the first working state, the distance between the actuator and the intake valve assembly is L1; when the drive 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 first protrusion protrudes by a dimension greater than L2 and less than L1 relative to the base circle.

[0029] Along the radial direction of the intake cam, the second protrusion protrudes more than L1 relative to the base circle.

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

[0031] A vehicle includes an engine, said engine being the engine described above.

[0032] This invention discloses an engine secondary compression release braking device. A drive mechanism changes the position of the actuator relative to the intake valve assembly, and a first protrusion is provided on the intake cam. During engine operation, when the crankshaft rotates to the power stroke, the first protrusion drives the intake rocker arm to rotate, and the actuator drives the intake valve to open, allowing air to enter the cylinder for a second compression release. In this embodiment, the intake valve ensures sufficient gas volume in the cylinder during the second compression release, thus guaranteeing the engine's braking power. Furthermore, the intake valve reduces the temperature of the gas entering the cylinder, thereby reducing the thermal load on the engine's fuel injectors, intake valves, and exhaust valves. Attached Figure Description

[0033] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0034] Figure 1 The valve lift curve is the engine secondary compression release braking method disclosed in the existing embodiments;

[0035] Figure 2 This is the valve lift curve of the engine secondary compression release braking method disclosed in the embodiments of the present invention;

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

[0037] Figure 4 This is a schematic diagram of the engine secondary compression release braking device disclosed in the embodiment of the present invention in the engine braking open state;

[0038] Figure 5 This is a schematic diagram of the structure of the actuator disclosed in the embodiments of the present invention;

[0039] Figure 6 This is a schematic diagram of the intake cam disclosed in an embodiment of the present invention. Detailed Implementation

[0040] This invention discloses a secondary compression release braking device for an engine to reduce the intake air temperature during the engine's power stroke, thereby reducing the thermal load on the engine's cylinders, intake manifold, and exhaust manifold. Furthermore, this invention also discloses an engine and a vehicle incorporating the aforementioned secondary compression release braking device.

[0041] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

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

[0043] like Figure 1 As shown, in some embodiments, the secondary compression release braking of the engine is achieved by: the exhaust main lift during the engine's positive stroke disappearing in advance, while the intake main lift is retained; and the opening and closing of a single exhaust valve during the entire engine stroke is controlled by an additional exhaust cam and exhaust rocker arm mechanism. The opening positions of the exhaust valves include: opening near the piston's top dead center to release high-pressure gas; and opening during the expansion stroke to allow exhaust gas to backflow into the cylinder, providing charge for the second compression release.

[0044] Specifically, Figure 1 The braking process of an engine: When the crankshaft angle is around 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. The braking exhaust stroke is relatively large, that is, the exhaust valve is in the open state. The air compressed by the piston is discharged through the exhaust valve, thus completing the first compression release.

[0045] As the crankshaft angle increases, the piston begins to descend, 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, allowing exhaust gas to flow back into the cylinder. This continues until the crankshaft rotates to around 180°, at which point the gas flowing back into the cylinder provides the charge for the engine's second compression stroke. It should be noted that because the exhaust valve opens at the end of the compression stroke, the compressed air is expelled through the exhaust valve, preventing the compressed gas from pushing the piston to do work; this completes the engine's first compression stroke.

[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 and exhaust valves are closed, and the piston compresses the gas flowing back into the cylinder. When the piston moves upward to near 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 engine completes its second compression and release.

[0047] As the crankshaft angle increases further, the piston begins to descend, and the engine enters the intake stroke (also known as the intake stroke). During this process, the intake valve is open and the exhaust valve is closed. 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, both the intake and exhaust valves are closed, and the fresh air in the cylinder is compressed until the piston moves to top dead center. At this point, the engine enters the end of the compression stroke, and the exhaust valve opens to release the compressed gas.

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

[0050] Based on the engine's operating process described above, it can be seen that during the secondary compression and release braking process, the second intake of air into the cylinder is achieved through exhaust backflow. Because the temperature of the compressed gas at the exhaust valve is relatively high, exhaust backflow increases the thermal load on the cylinder, intake manifold, and exhaust manifold, potentially damaging the fuel injectors. Furthermore, the high thermal load on the exhaust valve reduces its reliability.

[0051] In addition, during the exhaust stroke of the engine, when the piston reaches top dead center, the exhaust valve opens to release compressed gas, and the intake valve opens to allow fresh air to enter. That is, the intake and exhaust valves open overlapping, which can easily cause high-pressure and high-temperature gas at the exhaust valve to backflow into the intake pipe, damaging components such as the intake heating grille, intake pressure and temperature sensor, and intake throttle valve.

[0052] Based on the above issues, such as Figure 2 As shown in the embodiments of this application, a secondary compression release braking method for an engine is disclosed. This method involves opening the intake valve and closing the exhaust valve during the engine's power stroke, thereby allowing air to enter the cylinder through the intake valve and replenishing the cylinder's air supply. Compared to backflow of gas through the exhaust valve, this method allows cooler gas to enter the cylinder, thus reducing the impact of thermal load.

[0053] Specifically, Figure 2 The braking process of the engine is as follows: when the crankshaft angle is around 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. The braking exhaust stroke is relatively large, that is, the exhaust valve is in the open state. The air compressed by the piston is discharged through the exhaust valve, thus completing the first compression release.

[0054] As the crankshaft angle increases, the piston begins to descend, 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 engine cylinders and provide charge for the engine's second compression stroke. It should be noted that because the exhaust valve opens at the end of the compression stroke, the compressed air is expelled through the exhaust valve, preventing the compressed gas from pushing the piston to do work; this completes the engine's first compression stroke.

[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 and exhaust valves are closed, and the piston compresses the gas in the cylinder. When the piston moves upward to near 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 engine completes its second compression and release.

[0056] As the crankshaft angle increases further, the piston begins to descend, and the engine enters the intake stroke (also known as the intake stroke). During this process, the intake valve is open and the exhaust valve is closed. 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, both the intake and exhaust valves are closed, and the fresh air in the cylinder is compressed until the piston moves to top dead center. At this point, the engine enters the end of the compression stroke, and the exhaust valve opens to release the compressed gas.

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

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

[0060] The following describes the device that enables the engine to take in air using the intake valve during the power stroke.

[0061] like Figure 3 and Figure 4 As shown in the embodiments of this application, the engine secondary compression release braking device 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 both intake valves 11.

[0063] The intake cam 4 abuts against the first end of the intake rocker arm 3, driving the intake rocker arm 3 to rotate. The second end of the intake rocker arm 3 abuts against the intake valve bridge 12, driving the intake valve 11 to control the opening and closing of the intake passage of the cylinder. In some embodiments, the intake cam 4 and the intake rocker arm 3 can directly contact each other, or they can abut against each other via a push rod. During the rotation of the intake cam 4, the push rod is driven to move vertically, and the push rod drives the intake rocker arm 3 to rotate.

[0064] In this embodiment, the second end of the intake rocker arm 3 is provided with an actuator 2. The actuator 2 is telescopic 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 may also be mounted on the intake valve assembly 1, and the actuator 2 is movable relative to the intake valve assembly 1 toward the intake rocker arm 3. Exemplarily, the actuator 2 is mounted on the intake valve bridge 12.

[0065] The drive mechanism 5 is connected to the actuator 2 and is used to control the extension and retraction of the actuator 2 relative to the intake rocker arm 3. It should be noted that the drive mechanism 5 has two operating states. In the first operating state, the distance between the actuator 2 and the intake valve bridge 12 is the initial distance, denoted as L1 in this application. In the second operating state, the distance between the actuator 2 and the intake valve bridge 12 changes; specifically, the actuator 2 moves towards the intake valve bridge 12, reducing the distance between them. In this application, the distance between the actuator 2 and the intake valve bridge 12 in the second operating state is denoted as L2.

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

[0067] When the engine is engaged and braking is applied, the drive mechanism 5 drives the actuator 2 to move relative to the intake rocker arm 3 closer to the intake valve bridge 12, thereby reducing the distance between the second end of the intake rocker arm 3 and the intake valve bridge 12. During the engine's power stroke, the intake cam 4 rotates to the position of the first protrusion 41 of the intake cam 4. The intake cam 4 drives the intake rocker arm 3 to rotate, causing the second end of the intake rocker arm 3 to abut against the intake valve bridge 12, and driving the intake valve bridge 12 to simultaneously apply force to both intake valves, causing both intake valves 11 to open, and the engine charges the cylinders through the intake valves 11.

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

[0069] When the engine is turned off and the brakes are applied, the drive mechanism 5 drives the actuator 2 to move away from the intake rocker arm 3 relative to the intake valve bridge 12, creating a gap between the actuator 2 and the intake valve bridge 12. It should be noted that the size of this gap must satisfy the following condition: 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, meaning the intake valve 11 will not open, thus ensuring the normal operation of the engine.

[0070] The engine secondary compression release braking device in this embodiment utilizes a drive mechanism 5 to change the position of the actuator 2 relative to the intake valve bridge 12. A first protrusion 41 is provided on the intake cam 4. When the engine is running in the braking state, the crankshaft rotates to the power stroke state, and the first protrusion 41 drives the intake rocker arm 3, causing the actuator 2 to abut against the intake valve bridge 12, thereby opening the intake valve 11. The intake valve 11 then supplies air to the cylinder, enabling the engine to perform a second compression release. In this embodiment, during the power stroke, the intake valve ensures sufficient gas volume in the cylinder during the second compression release, thus guaranteeing the engine's braking power. Furthermore, the intake valve reduces the temperature of the gas entering the cylinder, thereby reducing the thermal load on the engine's fuel injectors, intake valves, and exhaust valves.

[0071] In some embodiments, the second end of the intake rocker arm 3 has a receiving groove, and the actuator 2 is telescopically mounted 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 drive mechanism 5 includes, but is not limited to, a hydraulic system. When the engine is in the power stroke, the hydraulic system is activated, and the hydraulic fluid drives the actuator 2 in the receiving groove to move towards the intake valve bridge 12, thereby reducing the distance between the actuator 2 and the intake valve bridge 12.

[0072] The structure of the hydraulic system can be configured according to different needs, as long as it can drive the actuator 2. For example, the drive mechanism 5 includes: a brake oil circuit, a first solenoid valve, and a second solenoid valve. The brake oil circuit includes an inlet pipe and an outlet pipe. The output end of the inlet pipe is connected to the receiving groove, and the input end of the outlet pipe is connected to the receiving groove. The specific structure of the inlet and outlet pipes can be configured according to different needs. The first solenoid valve controls the opening and closing of the inlet pipe, and the second solenoid valve controls the opening and closing of the outlet pipe. When the drive mechanism 5 is in the first working state, the first solenoid valve closes the inlet pipe, and the second solenoid valve opens the outlet pipe; the actuator 2 does not move within the receiving groove. When the drive mechanism 5 is in the second working state, the first solenoid valve opens the inlet pipe, and the second solenoid valve closes the outlet pipe; the actuator 2 moves within the receiving groove.

[0073] In other alternative embodiments, the drive mechanism 5 may also be an electromagnetic structure, which changes the position of the actuator 2 by gaining or losing electricity in the electromagnetic structure. For example, the drive mechanism 5 is a magnetic structure, and the actuator 2 is a magnetically attached metal component.

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

[0075] Combination Figures 3 to 5As shown, the execution mechanism 2 in this embodiment includes an execution body 21 and an elephant foot 22.

[0076] The actuator 21 includes, but is not limited to, a piston, which is movably mounted in the receiving groove of the intake rocker arm 3. A foot 22 is hinged to the side of the actuator 21 near the intake valve bridge 12. The foot 22 is hinged to the actuator 21, thereby ensuring that the lower surface of the foot 22 is always parallel and in contact with the intake valve bridge 12 during the process of driving the intake valve to open and the intake rocker arm 3 to rotate.

[0077] The end of the actuator 21 near the elephant foot 22 is spherical, and the elephant foot 22 has a spherical groove that connects with the spherical surface. The elephant foot 22 is hinged to the actuator 21 through the cooperation of the spherical surface and the spherical groove.

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

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

[0080] The base circle portion 43 and the second protrusion 42 form the main structure of the intake cam 4. The first protrusion 41 is disposed on the base circle portion 43 and protrudes from the base circle portion 43. The second protrusion 42 is eccentrically arranged relative to the rotation center of the intake cam 4, that is, the second protrusion 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; under the driving action, the intake cam rotates to the second protrusion position 42 and abuts against the intake rocker arm 3, driving the intake rocker arm 3 to rotate, thereby opening the intake valve 11.

[0082] It should be noted that, along the radial direction of the intake cam 4, the first protrusion 41 protrudes beyond the base circle 43 by a larger dimension than L2 (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 protrusion 41 abuts against the intake rocker arm 3, the actuator 2 can drive the intake valve bridge 12 to move, thereby opening the intake valve 11. Furthermore, the first protrusion 41 protrudes less 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), ensuring that when the engine is in the off-braking state, 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, i.e., the intake valve 11 will not open, thus ensuring the normal operation of the engine.

[0083] Along the radial direction of the intake cam 4, the second protrusion 42 protrudes more than L1 relative to the base circle portion 43, so as to ensure that during the process of the second protrusion 42 abutting against the intake rocker arm 3, the actuator 2 can abut against the intake valve bridge 12, so that the intake valve 11 can be opened.

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

[0085] As can be seen from the above embodiments, the engine secondary compression release braking device in this application eliminates the in-cylinder intake form of exhaust backflow, and still uses intake valve 11 to supplement the gas charge in the cylinder, thus reducing the thermal load in the cylinder and the intake and exhaust pipes. It retains the main intake lift, and the second intake also involves opening multiple intake valves, thus avoiding the valve bridge tilting and detachment problems that occur when opening a single intake valve. Its maximum lift can also be flexibly adjusted, thereby increasing the in-cylinder gas charge, achieving a higher maximum cylinder pressure, and further improving the engine's braking power.

[0086] Furthermore, this application also protects an engine, including an engine secondary compression release braking device, and the engine secondary compression release braking device is the engine secondary compression release braking device disclosed in the above embodiments. Therefore, the engine with the engine secondary compression release braking device also has all the above-mentioned technical effects, which will not be described in detail here.

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

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

[0089] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those 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 invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. An engine secondary compression release braking device, characterized in that, include: Intake valve assembly (1); The intake cam (4) includes a base circle portion (43), a first protrusion (41) disposed on the base circle portion (43), and a second protrusion (42) connected to the base circle portion (43). The intake rocker arm (3) 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 the range where the intake cam (4) and the intake rocker arm (3) abut against each other during the power stroke of the engine. An actuator (2) is located between the second end of the intake rocker arm (3) and the intake valve assembly (1), and is 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 drive mechanism (5) is used to drive the actuator (2) to move relative to the second end of the intake rocker arm (3); When the drive mechanism (5) is in the first working state, the distance between the actuator (2) and the intake valve assembly (1) is L1; when the drive mechanism (5) is in the 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 first protrusion (41) protrudes from the base circle (43) by a dimension greater than L2 and less than L1; Along the radial direction of the intake cam (4), the second protrusion (42) protrudes more than L1 relative to the base circle (43).

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

3. The engine secondary compression release braking 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) is movable relative to the intake rocker arm (3) toward the intake valve assembly (1).

4. The engine secondary compression release braking 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 movable along the receiving groove and is installed in 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 braking device according to claim 4, characterized in that, The actuator (2) includes: An execution body (21) is movably installed in the receiving slot; Elephant foot (22), which is hinged to the side of the actuator (21) near the intake valve assembly (1), and the elephant foot (22) is used to fit against the intake valve bridge (12).

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

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

8. The engine secondary compression release braking device according to claim 4, characterized in that, The drive mechanism (5) includes: The brake fluid circuit includes an inlet pipe and an outlet pipe, the output end of the inlet pipe is connected to the receiving groove, and the input end of the outlet pipe is connected to the receiving groove. The first solenoid valve is used to control the opening and closing of the oil inlet pipeline; The second solenoid valve is used to control the opening and closing of the oil outlet pipeline.

9. An engine, comprising a secondary compression release braking device, characterized in that, The engine secondary compression release braking device is the engine secondary compression release braking device as described in any one of claims 1 to 8.

10. A vehicle, comprising an engine, characterized in that, The engine is the engine as described in claim 9.

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