39 results about "Compression release" patented technology

The invention relates to the field of piston type internal combustion engines, in particular to a heavy-duty engine with a mechanical valve and two piston assemblies. According to the variable hydraulic exhaust valve mechanism of the heavy-duty engine, the hydraulic energy storage assembly and the mechanical valve are arranged, so that the heavy-duty engine using the variable hydraulic exhaust valve mechanism can be switched between a four-stroke ignition mode main lifting mode and a two-stroke compression release brake compression mode; meanwhile, mechanical valves used by multiple cylinders can be driven in a centralized mode by arranging one pilot electromagnetic valve.

An engine brake reset valve includes a cylindrical housing body having an end and a central cavity therein. The reset valve includes a first valve part attached to a second valve part, wherein the central cavity is sized to receive the first valve part and the second valve part. The first and second valve parts are movable within the central cavity between open and closed positions. When the second valve part is in a closed position, the second valve part engages and blocks the central orifice to prevent fluid pressure from entering the central orifice. When the second valve part is in an open position, the second valve part moves away from the central orifice to enable fluid pressure to enter the central orifice.

This invention relates to the field of heat dissipation airflow mesh technology, and provides an airflow mesh for passive airflow cooling, including a pipe assembly, a clamping assembly, and an adjusting assembly. The pipe assembly includes a main pipe, a secondary pipe, an adjusting pipe, a vertical plate, and a horizontal plate. The clamping assembly, sleeved on the outer wall of the adjusting pipe, includes a fixed plate, a movable part, a rotating plate, and a support block. The adjusting assembly is located at one end of the main pipe and inside the main and secondary pipes, and includes a motor, a rotating shaft located at the output end of the motor, a drive bevel gear sleeved on the end of the rotating shaft away from the motor, a rotating part located on the end of the drive bevel gear away from the rotating shaft, and a spiral part sleeved on the rotating part. The function of the pipe assembly is to connect traditional heat dissipation pipes in sections, and through the combined effect of the septum effect and Bernoulli's principle, to compress the gaseous working fluid and release heat, which is conducted away through the metal thermally conductive material, thereby reducing the temperature of the airflow after it passes through by approximately 50 watts / m² / m / s.

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.

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.

The invention discloses a supercharged engine and a vehicle, the supercharged engine comprises a cylinder, an exhaust passage and a cooling pipe, the cooling pipe comprises a main pipe and a branch pipe, the main pipe is communicated with a cold air supply device, one end of the branch pipe is communicated with the main pipe, the other end of the branch pipe is communicated with the cylinder, and a valve is arranged on the main pipe and / or the branch pipe. In the power stroke of secondary compression release braking, an exhaust valve of an exhaust passage is opened, exhaust backward flowing is carried out, meanwhile, a valve of a cooling pipe is opened, the cooling pipe supplies cold air into an air cylinder and provides charge for secondary compression release, meanwhile, the cold air is mixed with high-temperature waste of exhaust backward flowing, and the temperature of gas in the air cylinder is reduced. The temperature of the air in the air cylinder is reduced, the exhaust stroke of secondary compression release braking and the temperature after the piston moves upwards to the top dead center are also reduced and are lower than the temperature which can damage the oil sprayer, so that the risk of damage to the oil sprayer is reduced, correspondingly, the thermal load borne by the exhaust valve is also reduced, and the working reliability of the exhaust valve is ensured.

A compression-release engine brake system for operating at least one exhaust valve of an engine during an engine braking operation. The brake system comprises a lost motion exhaust rocker assembly and a dual stage hydraulic solenoid valve. The exhaust rocker assembly includes an exhaust rocker arm and a compression brake control module (CBCM). The CBCM maintains the at least one exhaust valve open when in the engine braking operation. The CBCM includes a casing, an actuation piston disposed outside the casing so as to define an actuation piston cavity, a reset check valve, and a compression brake actuator disposed in the casing. The actuation piston reciprocates relative to the casing. The compression brake actuator includes a control piston that engages the check valve when deactivated so as to unlock the actuation piston cavity and disengages from the check valve when activated so as to lock the actuation piston cavity.

The present invention provides a compression release device, which relates to the field of aerospace technology. The compression release device includes a locking assembly and an unlocking assembly. The locking assembly includes a locking rope, a locking sleeve, a petal clamp, a compression rod and a fixed seat. The fixed seat is slidably connected to the locking sleeve. The locking rope is used to lock the locking sleeve on the fixed seat. The locking sleeve is used to be sleeved on the petal clamp. The petal clamp has a closed state and a separated state. When the petal clamp is in the closed state, the petal clamp clamps the compression rod. When the petal clamp is in the separated state, the petal clamp is separated from the compression rod. The unlocking assembly is used to disconnect the locking rope to separate the locking sleeve from the fixed seat. The present invention locks the petal clamp by the locking sleeve, can withstand a greater preload, is not limited to small satellites, and improves applicability. The method of disconnecting the locking rope by the unlocking assembly is safer and more environmentally friendly than the design of pyrotechnic products, can be reused, and reduces impact force.

To provide an engine control device that can rapidly raise the temperature of the catalyst and maintain an appropriate temperature. [Solution] An engine control device for controlling an engine, wherein when the catalyst temperature of a catalyst that purifies the exhaust gas of the engine is below a first threshold temperature, it performs compression release control to stop fuel injection from the injector in selected cylinders, which are some of the cylinders among a plurality of cylinders of the engine, and increase the amount of fuel injected in non-selected cylinders different from the selected cylinders, and when the catalyst temperature is above the first threshold temperature, it performs Miller cycle control to operate the intake valve to reduce the amount of intake air in all of the plurality of cylinders compared to when the temperature is below the first threshold temperature, and to control the amount of fuel injected.

The utility model is applicable to the field of screw air compressors, and provides a screw air compressor heat energy recovery device which comprises a case, a compression assembly arranged in the case and a heat recovery assembly arranged in the case, the case comprises a water tank, an air inlet, an air outlet, a liquid inlet and a liquid outlet, the compression assembly comprises a driving screw and a driven screw, and the heat recovery assembly comprises a heat recovery assembly. The heat recovery assembly comprises an air distribution plate, a plurality of heat dissipation pipes and an air collection pipe, the water tank is filled with water through a liquid inlet, air can be sucked from an air inlet during rotation by rotating a driving screw rod and a driven screw rod which are meshed with each other, and then the air is discharged into the air distribution plate from an air guide pipe after being rotationally compressed, so that the air pressure is increased, and the heat recovery efficiency is improved. The compressed high-temperature air releases heat through the heat dissipation pipe to enter water to heat the water, then heat energy of the air is recycled, the compressed air releasing the heat is discharged from the air outlet through the air collection pipe, and hot water is discharged from the liquid outlet.

The present invention relates to the field of piston internal combustion engines. A heavy-duty engine with cylinders switchable between single-valve and dual-valve actuation is provided. By providing a cam member with a unique cam profile and combining the cam member with a control assembly, a continuously variable hydraulic valvetrain can be switched between single-valve and dual-valve actuation. Furthermore, by providing a control assembly comprising multiple valve members located in different positions, dual-valve exhaust main lift or cylinder deactivation, as well as single-valve compression release braking and early exhaust valve opening and closing, are further implemented.

The utility model belongs to the technical field of vehicles, and discloses a valve driving device and a vehicle. The valve driving device comprises a rocker arm and an adjusting assembly, a containing cavity is formed in the rocker arm, the adjusting assembly comprises an adjusting piece, an adjusting valve, a brake piston and a reset piece, the adjusting piece and the brake piston are slidably arranged at the two ends of a piston body respectively, and the first end of the adjusting piece and the first end of the brake piston are oppositely arranged; the adjusting valve is arranged between the adjusting piece and the brake piston, the adjusting valve slides along the rocker arm and can adjust the lift of the air valve abutting against the brake piston, and the reset piece can guarantee normal reset of the adjusting valve. According to the valve driving device and the vehicle, the air inlet amount of the valve in the air inlet stroke can be increased, the braking power released through first-time compression of high-power braking is improved, the valve driving device can be opened again in the working stroke, fresh air enters a cylinder, and the proportion of fresh air released through second-time compression of high-power braking is increased; and the heat load released by second-time compression in high-power braking is reduced.

A compression-release engine brake system for operating at least one exhaust valve of an engine during an engine braking operation. The brake system comprises a lost motion exhaust rocker assembly and a dual stage hydraulic solenoid valve. The exhaust rocker assembly includes an exhaust rocker arm and a compression brake control module (CBCM). The CBCM maintains the at least one exhaust valve open when in the engine braking operation. The CBCM includes a casing, an actuation piston disposed outside the casing so as to define an actuation piston cavity, a reset check valve, and a compression brake actuator disposed in the casing. The actuation piston reciprocates relative to the casing. The compression brake actuator includes a control piston that engages the check valve when deactivated so as to unlock the actuation piston cavity and disengages from the check valve when activated so as to lock the actuation piston cavity.

The utility model discloses a spring compression and release electric reciprocating device of adjustable output force value relates to mechanical device technical field. It includes the device ontology, and the ontology contains with the ejection trigger gear that reduction motor output shaft links to each other, is installed in the gear on the limit sliding block trigger dial, the connecting module, the limit sliding block of small spring area pull rod, and the connecting module is connected with the pull rod reduction motor, and the bottom is equipped with hollow adjusting bolt, and the pull rod is covered in the connecting module and bolt, and the module top end resistance touches the limit baffle ring of pull rod upper end portion, and the hollow adjusting bolt outer wall cover precision locking nut (diagonal set locking use fixed small hole), and the pull rod and bolt combination outer circle cover big spring, and big spring upper end connects precision locking nut, and lower end is equipped with fixed base, and pull rod bottom end is equipped with the head of spring. The device realizes spring compression release automation, and the structure is compact, can adjust output force value, is applicable to spring impactor, mortar penetration instrument, orthopedics dismantles nail and automobile sheet metal scene.

The present application relates to the technical field of space release mechanism, and particularly relates to a fuse type compression release mechanism. The fuse type compression release mechanism provided by the present application comprises a compression seat, a compression bushing, a compression structure, a tensioning rope and a fuse assembly. The compression bushing is arranged between the compression structure and the compression seat. The tensioning rope is used to connect the compression seat and the compression structure, so as to compress the compression bushing on the compression seat. The fuse assembly comprises a resistance wire, which is used to fuse the tensioning rope. The present application realizes compression locking by using the physical tensioning force of the tensioning rope, and realizes release by fusing the tensioning rope through the resistance wire in the fuse assembly. The present application has simple structure and high reliability. Since the fuse type tensioning rope is adopted, the present application does not need to rely on the action of triggering powder, has small impact during release, does not produce harmful gas, and can be reused by replacing the tensioning rope.

The application designs a high-load high-precision light loading device for solar wing ground assembly, which is composed of a loading assembly and a fine adjustment assembly, the loading assembly includes a loading interface module and a driving module, wherein the loading interface module is installed at the front end of the driving module, the loading interface module is used to ensure that the steel belt in the compression release device is uniformly stressed during loading, and the driving module provides driving force for the whole loading assembly and ensures high-precision loading; the loading assembly is driven by a servo motor, and motion conversion is realized by using a ball screw transmission, and the loading motion is transmitted to the compression release device through a transmission chain, aiming to meet the ground loading demand of single-point accurate loading during the compression assembly of the circular solar wing; the fine adjustment mechanism is used to realize the fine adjustment of the assembly position of the loading device and the target of unloading the gravity of the loading device.

The application belongs to the technical field of material grinding and crushing, and particularly relates to a crushing device for fish meal processing, which comprises an automatic pulse spraying system, a double-path spraying pipe, a screen grading mechanism and a grinding and crushing mechanism. The automatic pulse spraying system comprises a gas compression assembly, a jet gas valve assembly, a wind pump assembly and a spraying shell. The gas compression assembly is rotationally arranged in the spraying shell. The jet gas valve assembly is symmetrically arranged in the gas compression assembly. The wind pump assembly is arranged on the spraying shell. In the process of continuously conveying materials through airflow, the device can also intermittently generate pulse airflow with increased pressure. On the one hand, the device can reduce the contact between powder materials and the pipe wall. On the other hand, the device can also strip the materials that have been attached. Through the structural design of the automatic pulse spraying system, the device can automatically complete the gas compression release and turning of the compression chamber while the central rotating shaft of the wind pump body rotates.

The present invention discloses an emergency release device for a connecting shaft, which relates to the field of motor test benches, and comprises: a first end, wherein at least one first slot is provided on the outer periphery of the first end; a second end, wherein at least one second slot is provided on the outer periphery of the second end; a separation mechanism, which is arranged between the first end and the second end, and the separation mechanism comprises a movable clamping member, wherein both ends of the clamping member respectively cooperate with the first slot and the second slot; the release device is compressed and released by the clamping member in the separation mechanism, and both ends of the clamping member are quickly separated from the first slot and the second slot, so that the vehicle can be quickly released, thereby saving the progress of the test and subsequent tests.

The present application relates to the field of aerospace technology, in particular to a kind of deployment testing device under thermal vacuum environment, including support mechanism, sliding mechanism and compression release mechanism;Support mechanism is placed in fixed surface, sliding mechanism is arranged on the upper surface of support mechanism, lifting mechanism is arranged at one end of support mechanism, and is connected with sliding mechanism, sliding mechanism is used to guide when lifting mechanism is deployed;Compression release mechanism is at least one and is arranged in support mechanism, and is communicated with power supply, initially, compression release mechanism is used to compress lifting mechanism, after power on, compression release mechanism releases lifting mechanism.The deployment testing device under thermal vacuum environment provided by the present application significantly improves the accuracy and reliability of test results, and provides strong guarantee for the effectiveness of solar wing on-orbit deployment.

The present invention provides a compression release device, comprising: a shell, a pushing mechanism, a self-locking mechanism, a triggering and tightening mechanism, and a claw mechanism. The released body is mounted on the top of the shell and is clamped by the retracted claw mechanism. The bottom of the pushing mechanism is mounted on the bottom plate of the shell through a thruster, and the top of the pushing mechanism is connected to the self-locking mechanism through a linkage rod. The triggering and tightening mechanism is mounted on at least one side of the pushing mechanism, and is used to extend after being triggered to press the pushing mechanism in a pre-tightened position, or retract after being triggered to release the pressure on the pushing mechanism. The claw mechanism is arranged on the side of the triggering and tightening mechanism away from the thruster, and is connected to the self-locking mechanism by an action rod. The self-locking mechanism is configured to self-lock when it is parallel to the action rod, and release the self-locking when the parallel state is broken; the compression release device of the present invention does not need to be triggered and released by pyrotechnics, so it can be repeatedly tested and used, greatly improving reliability.

The utility model relates to the technical field of masonry strength detection, concretely refers to a kind of masonry strength on-site detection device, including handle part, the handle part one side is fixed with support, slidingly connected with movable frame on the handle part, working spring is further connected between the movable frame and handle part, while rotating drum is rotated on the movable frame, pressure release sliding slot is opened on the rotating drum side wall, sliding block is arranged on the support, the sliding block slides along pressure release sliding slot, receiving cylinder is rotatably installed on the support and located in the front end of rotating drum, a plurality of receiving holes for inserting and placing measuring nail are opened on the receiving cylinder, connecting rod is fixed on the movable frame, the protruding plate is fixed on the front end of connecting rod after passing through the center of rotating drum, the protruding rod is fixed on the front end of protruding plate, multiple measuring nails can be filled simultaneously, the compression release of working spring and the conversion push-out of measuring nail are carried out synchronously by using motor to drive power shaft to rotate, a large amount of operation time is saved.

The invention relates to the technical field of spaceflight, in particular to an unfolding test device in a thermal vacuum environment, which comprises a supporting mechanism, a sliding mechanism and a pressing and releasing mechanism, the supporting mechanism is placed on the fixed face, the sliding mechanism is arranged on the upper surface of the supporting mechanism, the lifting mechanism is arranged at one end of the supporting mechanism and connected with the sliding mechanism, and the sliding mechanism is used for guiding the lifting mechanism when the lifting mechanism is unfolded. The at least one pressing and releasing mechanism is arranged on the supporting mechanism and communicated with the power source, at the beginning, the pressing and releasing mechanism is used for pressing the lifting mechanism, and after being powered on, the pressing and releasing mechanism releases the lifting mechanism. According to the unfolding test device in the thermal vacuum environment, the accuracy and the reliability of a test result are remarkably improved, and a powerful guarantee is provided for the effectiveness of solar wing on-orbit unfolding.

The invention discloses a production device and process of a molding material for casting, and particularly relates to the technical field of casting, the production device comprises a rack, a vibration feeding hopper, a discharging conveying belt, a driving motor and a jaw breaking box mechanism, and a movable jaw mechanism and a buffer pneumatic mechanism are arranged in the jaw breaking box mechanism. Through mutual cooperation of the jaw box breaking mechanism, the movable jaw mechanism, the transmission mechanism and the buffer pneumatic mechanism, a movable toothed plate capable of sliding left and right on a movable jaw plate and a fixed toothed plate form dynamic staggered engagement, and are horizontally staggered with tooth peaks of the fixed jaw plate in reciprocating motion to synchronously generate a shearing friction effect, so that fine materials are effectively prevented from escaping from tooth seams, and the service life of the fine materials is prolonged. The crushing ratio and the finished product granularity uniformity are improved; meanwhile, the movable jaw plate reciprocates to drive the buffer rod to drive the air cylinder to conduct air compression-release circulation, high-pressure airflow is directionally jetted to the root of the movable toothed plate through the air distribution pipe, accumulated scraps at the tooth root are removed in real time through the ventilation characteristic of the unilateral dispersion air pipe, and continuous and stable operation of equipment is guaranteed.

The application discloses a kind of side one-way exhaust shoes of built-in air guide channel, it is related to shoe technical field, including vamp, exhaust mechanism and shoelace, the bottom of vamp is integrally die casting and is formed with exhaust mechanism, exhaust mechanism is set, through the action of foot sole treading and lifting driving air bag compression release, first one-way valve and second one-way valve are pushed using air pressure difference to realize one-way conduction, realize the one-way air guide effect of directional exhaust of hot gas and moisture in shoe, effective barrier of outside mud and dust, continuously keep dry in shoe;Sealing mechanism is set, long-term stable waterproof dustproof sealing between shoe sole and non-slip pad is realized by a variety of material layers, and the problem of seepage water into ash, fitting failure is eliminated.

The invention relates to the technical field of rubber and plastic mixing processing, in particular to a continuous internal mixer unit based on a wedge-shaped rotor, which comprises a motor, the output end of the motor is provided with a gear box, the output end of the gear box is provided with a feeding machine, the output end of the feeding machine is provided with an internal mixer, the output end of the internal mixer is provided with a double-screw extruder, and the output end of the double-screw extruder is provided with a wedge-shaped rotor. And a discharging bin is arranged at the output end of the double-screw extruder. According to the invention, the wedge-shaped rotor structure of the internal mixer is connected in series with the twin-screw extruder, so that the combination of efficient dispersion and mixing and continuous production is realized, the unique geometric design of the wedge-shaped rotor forms a compression-release area, the shearing and kneading effects are enhanced, and the wedge-shaped rotor is matched with twin-screw extrusion to further homogenize the material and exhaust the gas; an intelligent heat dissipation system is adopted for a motor, a cylindrical cam mechanism is driven through internal mixing load fluctuation, an automatic valve and a heat dissipation fan are linked through a pressure sensor, a crossed air channel is formed, heat dissipation according to needs is achieved, and automatic closing and dust prevention are achieved during shutdown.

The invention relates to the field of combustion engines. A heavy duty combustion engine is provided. The heavy-duty combustion engine includes a variable hydraulic valve mechanism by combining a single cam member having a dedicated cam profile, a valve return brake assembly, and a switching solenoid valve, two-stroke compression release braking with two exhaust valves opened at the same time and advanced opening and closing of the exhaust valves in a normal ignition mode are achieved; specifically, the cam profile of the cam member is provided with four continuous ramp-up stages, so that the four continuous ramp-up stages cover a compression release lift in a CRB 1.5 compression release braking mode, an early exhaust valve opening / closing in an ignition mode, and an exhaust main lift in a normal ignition mode.

The present invention discloses a compression release type in-cylinder braking system for an engine, which includes a valve train, an oil cylinder device, an oil pumping device and an oil supply device. The oil cylinder device and the oil pumping device of each cylinder are connected through a pressure transmission oil circuit. The pressure transmission oil circuit is connected to the oil supply device through a low-pressure relief valve, and an air release valve is provided at the high end of the oil circuit system. During in-cylinder braking, the air release valve is closed, the electromagnetic reversing valve is energized, and engine oil with a pressure of P1 is supplied to the pressure transmission oil circuit. The cam abuts against and pushes the oil pumping device to pump high-pressure oil to the oil cylinder device to push the rocker arm to open the valve, thereby realizing in-cylinder braking. During non-in-cylinder braking, the air release valve is opened, the electromagnetic reversing valve is de-energized, and engine oil with a pressure of P2 is supplied to the pressure transmission oil circuit, where P1 > P2. The oil cylinder device and the oil pumping device return to their original positions respectively, and the cam is disengaged from the oil pumping device. The compression release type in-cylinder braking system of the present invention has stable and reliable operation, a simple oil circuit structure, and is not limited by the number of engine cylinders.

The invention discloses a mechanical braking and in-cylinder compression release braking combined control method and system, and relates to the technical field of service braking. Comprising the following steps: collecting historical data, setting an activation condition, dividing scenes according to a vehicle speed difference value, a road gradient and a road adhesion coefficient, marking priorities, and generating scene labels; the method comprises the following steps: collecting real-time data of a vehicle, a driving condition and operation, and preprocessing the collected real-time data; according to the technical key points, historical data are analyzed, labels are given to different scenes, the problems that in the current brake technology, the starting precision is insufficient, and the applicable scene is single are solved, braking can be accurately started under various conditions, data are collected through active input, automatic judgment and scene adaptation, and the braking precision is improved. Scenes are divided in combination with the vehicle speed difference, the gradient and the road condition, response is rapid, accuracy is high, false triggering can be effectively avoided, meanwhile, an accurate scene basis is provided for a subsequent control strategy, and the method has a good use prospect.

A mechanical clutch boosting structure of a clutch relates to the technical field of boosting structures and comprises a side plate, a clutch brake pedal arm is hinged to the side plate, an elastic component is hinged to the side plate, the swing end of a boosting rocker arm is hinged to the pressing end of the elastic component, and when the clutch brake pedal arm is in an initial state, the elastic component pushes the clutch brake pedal arm outwards; when the clutch brake pedal arm is stepped down, the power-assisted rocker arm swings downwards to compress the elastic assembly to a polar point, and the clutch brake pedal arm is located at a first-stage power-assisted position; when the clutch brake pedal arm is continuously treaded down, the power assisting rocker arm crosses the first-stage power assisting position, the elastic assembly is compressed and released to push the power assisting rocker arm to swing upwards, and the clutch brake pedal arm is driven to be located at the second-stage power assisting position. The power assisting structure solves the problems that normal operation of a hydraulic oil cylinder in a power assisting structure in the prior art depends on pressure provided by a hydraulic system, if the pressure of the hydraulic system is too high, adverse effects can be generated on the service life of related components, and oil leakage and abnormal sound are prone to occurring.

The present invention relates to the field of combustion engines. The present invention provides a heavy-duty combustion engine. The heavy-duty combustion engine includes a variable hydraulic valvetrain. The variable hydraulic valvetrain combines a single cam member with a dedicated cam profile, a valve return brake assembly, and a switching solenoid valve to achieve two-stroke compression-release braking with simultaneous opening of both exhaust valves, as well as early exhaust valve opening and closing in normal ignition mode. Specifically, the cam profile of the cam member is configured to comprise four consecutive ramp-up stages, so that the four consecutive ramp-up stages encompass the compression release lift in the CRB1.5 compression-release braking mode, the early exhaust valve opening / closing in the ignition mode, and the exhaust main lift in the normal ignition mode.