CN218882313U

CN218882313U - Electric control hydraulic exhaust valve brake device of diesel engine

Info

Publication number: CN218882313U
Application number: CN202223401881.7U
Authority: CN
Inventors: 孙超; 孙沫; 李晓刚; 邢海军; 郑帅; 李海彬; 张永胜
Original assignee: Dongfeng Chaoyang Diesel Co Ltd
Current assignee: Dongfeng Chaoyang Diesel Co Ltd
Priority date: 2022-12-19
Filing date: 2022-12-19
Publication date: 2023-04-18
Anticipated expiration: 2032-12-19

Abstract

The utility model discloses an automatically controlled hydraulic pressure exhaust valve arresting gear of diesel engine, this arresting gear install on the inside rocker arm seat of engine rocking arm room cover, the stopper support is integral, and internally arranged has the oil duct, communicates with each other with engine pressure machine oil to break-make through solenoid valve control machine oil. The upper edge of the exhaust valve rocker arm of each cylinder is provided with a hydraulic piston corresponding to the position of the exhaust valve, when the exhaust valve is required to brake, an exhaust brake switch is opened, the electromagnetic valve is opened, and engine pressure engine oil enters a brake main oil duct. The main oil duct is communicated with a hydraulic piston above an exhaust valve rocker of each cylinder on the braking device, and the hydraulic piston of each cylinder extends out for a section of stroke under the pressure of oil to press the upper edge of the exhaust valve rocker to prevent the exhaust valve from being completely closed. During the compression stroke, the air is exhausted while being compressed in the air cylinder, and the piston is rebounded due to the fact that no pressure gas exists during the expansion stroke, so that pumping loss is generated, the automobile is decelerated by means of engine braking, and a larger braking effect is achieved.

Description

Electric control hydraulic exhaust valve brake device of diesel engine

Technical Field

The utility model belongs to the engine structure technique, concretely relates to automatically controlled hydraulic pressure exhaust valve arresting gear.

Background

Exhaust valve braking is a device mounted on an engine to assist in braking and decelerating a vehicle. Because the total mass of the heavy-duty truck is large and the inertia is large, a very strong braking force is needed to control the speed of the truck when the truck descends, and at the moment, a driver must frequently or for a long time step on a brake (main brake for driving) to reduce the speed of the truck. However, when a driver of a bicycle is frequently used for braking, a large amount of heat is generated by violent friction between the friction plate and the brake drum, and the heat cannot be dissipated in a short time, so that the phenomenon of brake heat fading occurs at this time, the braking force is reduced sharply, and the driving safety is influenced.

Although most trucks are equipped with an exhaust brake butterfly valve to assist braking, the braking mode only generates braking force by closing an exhaust pipeline and increasing exhaust back pressure, the braking power provided by the braking mode is limited, and the braking performance may not meet the requirement. Particularly, the condition that a heavy-load truck cannot brake the truck frequently occurs in a long downhill section in a mountainous area. Too high a speed of a vehicle not only can cause a driving safety problem, but also improper gear selection of a gearbox can cause overspeed of an engine and damage the engine.

The utility model provides an automatically controlled hydraulic pressure exhaust valve arresting gear slows down the speed of a motor vehicle at the independent control beyond vehicle main braking system, belongs to the auxiliary brake who improves driving safety. When the vehicle does not need to be braked and decelerated, the engine is in a normal working state, and when the vehicle needs auxiliary braking and deceleration under the conditions of heavy load, long slope and the like, a driver steps on the brake to brake actively and simultaneously turns on the auxiliary brake switch to enable the auxiliary brake device to act. The engine at this time is equivalent to an air compressor, and not only does not work externally, but also resistance is generated, which hinders the operation of the piston link mechanism. The principle is that pumping loss is generated through the throttling action of an exhaust valve braking device, kinetic energy of vehicle operation is absorbed, and the purposes of reducing vehicle speed and preventing the vehicle from operating are achieved.

The exhaust valve braking device can generate larger braking force to reduce the vehicle speed, thereby reducing the use frequency and time of the wheel main brake, reducing the loss of friction plates and prolonging the service life of a braking system. Therefore, the safety of the large vehicle running on the mountain road is improved, the exhaust back pressure can be reduced, and the engine is protected.

Disclosure of Invention

The utility model aims at providing an automatically controlled hydraulic pressure exhaust valve arresting gear of diesel engine belongs to the independent control outside the vehicle main braking system, strengthens the auxiliary brake who improves brake function, also is called the braking in the jar.

The technical proposal adopted for realizing the purpose of the utility model is that the integral type electric control hydraulic exhaust valve braking device for the engine comprises: the exhaust valve brake device comprises an exhaust valve brake bracket, a front rocker arm seat, a middle rocker arm seat, an electromagnetic valve, a hydraulic piston, an exhaust valve rocker arm, an exhaust valve, a screw plug, a brake clearance adjusting screw, a bolt, a nut and the like. The design structure is as follows: the brake support is fixed on the middle rocker arm seat and the front rocker arm seat through bolts, a brake oil inlet channel is arranged at the front end of the brake support in the vertical direction, the oil channel is communicated with a vertical oil channel on the front rocker arm seat, and high-pressure engine oil from an engine enters the brake support through the front rocker arm seat. An electromagnetic valve oil inlet channel is horizontally arranged at the upper end of the brake oil inlet channel, the electromagnetic valve is also arranged in the middle of the front end of the brake support, the electromagnetic valve oil inlet channel is communicated with an oil inlet of the electromagnetic valve, and an oil outlet of the electromagnetic valve is communicated with an electromagnetic valve oil outlet channel and a brake main oil channel. Meanwhile, the main oil duct is communicated with the hydraulic pistons of the cylinders, and the main oil duct, the electromagnetic valve oil inlet duct and the electromagnetic valve oil outlet duct are plugged by a plug arranged at the front end of the brake support to seal the oil ducts in the brake. When the exhaust brake switch is opened, the electromagnetic valve communicates the oil inlet channel with the oil outlet channel, high-pressure engine oil of the engine enters the main oil channel of the brake through the electromagnetic valve, reaches the hydraulic piston of each cylinder, pushes the hydraulic piston to extend and move downwards, and presses the front end of the exhaust valve rocker arm, so that the exhaust valve is prevented from being closed.

The technical scheme of the brake clearance adjusting screw designed on the upper part of the hydraulic piston in the brake bracket is very important, and although the structure is simpler, the function of adjusting the brake clearance during the assembly of the engine is very large, and the operation is simple. The clearance between the hydraulic piston and the exhaust valve rocker arm can be conveniently adjusted only by rotating the adjusting screw clockwise or anticlockwise, and the adjusting screw is locked by the nut after the adjustment is finished.

The innovation points of the device are as follows: (1) The structure and the component mounting mode of the integral brake bracket; (2) an arrangement structure of an internal oil passage of the brake bracket; (3) the brake directly takes oil from the rocker arm seat; (4) controlling the on-off mode of the oil way by the electromagnetic valve; and (5) arranging the hydraulic piston on the brake.

The principle of the device is as follows: a set of integral electric control hydraulic exhaust valve braking device is arranged on the upper edge of a rocker arm inside a rocker arm chamber cover of the engine and is matched with an exhaust braking butterfly valve to work in a combined mode. The brake device is internally provided with an oil duct which is communicated with engine pressure oil and controls the on-off of the engine oil through a solenoid valve. The brake is controlled by an electromagnetic valve, and high-pressure engine oil led into the engine pushes a hydraulic piston to extend out, so that the seating of an exhaust valve is controlled, and the engine generates braking force by pumping loss to reduce the speed of the vehicle. The brake support with an integral structure is arranged on the rocker arm seat, oil is directly taken from the rocker arm seat, and the braking of the four hydraulic pistons is realized by opening the electromagnetic valve and the main oil duct communicated with the upper part of the pistons, so that the control of the exhaust valve braking device is realized.

The utility model discloses a characteristics and beneficial effect who produces are: by opening the exhaust brake control device (in a cab), larger braking force is generated to reduce the speed of the vehicle, the use frequency and time of the wheel main brake are effectively reduced, the loss of friction plates is reduced, the engine does not work outwards, and resistance is generated to hinder the operation of the piston connecting rod mechanism. The safety of large vehicles running on mountain roads is improved, exhaust back pressure can be reduced, and the engine is protected. The braking device has the characteristics of simple structure, convenient operation, large braking power and small change to the original engine.

Drawings

Fig. 1 is a top view of the principles and structure of the present invention.

Fig. 2 is a perspective view of the principle and structure of the present invention.

Fig. 3 is a sectional structural diagram of the integrated electronic control hydraulic exhaust valve braking device in the front view direction.

Fig. 4 is a sectional structure diagram of the side surface of the integrated electric control hydraulic exhaust valve braking device.

Fig. 5 is a diagram of the solenoid valve control oil circuit of the integrated electric control hydraulic exhaust valve braking device.

Detailed Description

The structure of the present invention will be further described with reference to the following embodiments, but the present invention is not limited to the following embodiments.

The electrically controlled hydraulic exhaust valve brake for diesel engine has the specific structure: the brake support 1 is fixed on a middle rocker arm seat 3 and a front rocker arm seat 4 through bolts 2, a brake oil inlet channel 5 is arranged at the front end of the brake support in the vertical direction and is communicated with a vertical oil channel 6 on the front rocker arm seat, and high-pressure engine oil from an engine enters the brake support through the front rocker arm seat. An electromagnetic valve oil inlet channel 7 is horizontally arranged at the upper end of the brake oil inlet channel, an electromagnetic valve 8 is arranged in the middle of the front end of the brake support, the electromagnetic valve oil inlet channel is communicated with an oil inlet 8-1 of the electromagnetic valve, an oil outlet 8-2 of the electromagnetic valve is communicated with an electromagnetic valve oil outlet channel 9 and a brake main oil channel 10, and meanwhile, the main oil channel is communicated with hydraulic pistons 11 of all cylinders.

The main oil duct, the electromagnetic valve oil inlet duct and the electromagnetic valve oil outlet duct are plugged by a plug 12 arranged at the front end of the brake bracket, so that the oil duct in the brake is closed (as shown in figure 5). When the exhaust brake switch is opened, the electromagnetic valve communicates the oil inlet channel with the oil outlet channel, the high-pressure engine oil of the engine enters the brake main oil channel through the electromagnetic valve, reaches the hydraulic piston of each cylinder, pushes the hydraulic piston to extend and move downwards, presses the front end of the exhaust valve rocker arm 13 (the exhaust valve rocker arm cannot rotate), and therefore the exhaust valve 14 is prevented from being closed (as shown in fig. 4).

In this way, the effect of compression and exhaust is generated in the cylinder at the compression stroke stage of the piston, no pressure gas rebounds the piston at the expansion stroke stage, and pumping loss is generated by the throttling action of the exhaust valve braking device. The engine at this time is equivalent to an air compressor, and not only does not work externally, but also can generate resistance. The air is pushed against the piston connecting rod mechanism to block the operation of the piston connecting rod mechanism and increase the friction resistance of the air compressor connecting rod. The invention uses the brake of the engine (or the action of the cylinder connecting rod) to decelerate the automobile, thereby achieving a greater brake effect.

When the exhaust brake switch is closed, the oil inlet of the brake is closed because the electromagnetic valve of the brake is closed, and engine oil cannot enter the brake. Meanwhile, an oil drain port 8-3 of the electromagnetic valve is opened, the pressure engine oil in the brake main oil gallery is drained through the oil drain port of the electromagnetic valve, the hydraulic piston retracts (moves upwards), and the brake stops working (as shown in figure 5). The exhaust valve is returned to be opened and closed normally, and the engine enters a normal operation working mode.

The upper part of the hydraulic piston in the brake bracket is provided with a brake clearance adjusting screw 16, the clearance between the hydraulic piston and the exhaust valve rocker arm is adjusted by the upward anticlockwise rotation or downward clockwise rotation of the adjusting screw, and the adjusting screw is fixed by a nut 15.

Three sections of large reinforcing ribs 1-1 are arranged in the horizontal direction between hydraulic piston holes of each cylinder at the top of the brake support and are connected, the brake support is provided with 9 bolt hole umbilicals 1-2, a vertical middle reinforcing rib 1-3 is arranged between the two bolt hole umbilicals of each cylinder, a vertical small reinforcing rib 1-4 is arranged between the hydraulic piston hole of each cylinder and the bolt hole umbilicals, three sections of inner reinforcing ribs 1-5 are horizontally arranged on the back surface of the brake support, and the inner reinforcing ribs are vertically and crossly connected with the large reinforcing ribs, the middle reinforcing ribs and the small reinforcing ribs and penetrate through the 9 bolt hole umbilicals to form a cross framework structure. The brake bracket is ensured to have sufficient strength and rigidity to withstand the force from the valve spring, and vibration and noise can be reduced. The umbilical and the brake bracket are made of the same casting, through holes are processed on the umbilical, and the mounting bolts penetrate through the umbilical.

In order to achieve better braking effect, the clearance between the brake hydraulic piston and the exhaust valve rocker arm (brake clearance) needs to be determined by calibration tests to be the best value. The brake clearance of different models is different and must be adjusted according to requirements. Too large or too small clearance of the brake can affect the braking performance of the brake, and too small clearance can lead to untight closing of an exhaust valve and power reduction of an engine during normal work and even lead to collision of the exhaust valve and a piston, so that the clearance needs to be adjusted according to the specified requirement. The engine with the exhaust valve brake needs to adjust the brake clearance to a specified design value during production and assembly, and needs to be adjusted periodically during use. The adjustment period of the brake clearance is the same as the valve clearance adjustment period, and the brake clearance and the valve clearance are required to be adjusted together when the engine is maintained, and the adjustment method is similar to the valve clearance adjustment method.

In the example of the 4BK engine, when the brake is actuated, the hydraulic piston is moved up and down by 1.8mm, and after the hydraulic piston passes through a brake gap of 0.8mm, the hydraulic piston is pressed against the exhaust rocker arm, so that the exhaust valve is opened by 1.0mm.

The clearance adjusting method between the hydraulic piston of the brake and the rocker arm of the exhaust valve comprises the following steps: after the exhaust valve clearance of each cylinder is adjusted according to normal requirements, a nut 15 at the upper end of a hydraulic piston of the brake is loosened, an adjusting screw 16 is rotated upwards and anticlockwise, and then the hydraulic piston is shifted to be away from an exhaust valve rocker arm so as to conveniently insert a feeler gauge. The lower end of the exhaust valve rocker arm is in contact with the upper end face of the exhaust valve, a clearance gauge of 0.8mm is placed between a platform at the upper end of the exhaust valve rocker arm and the hydraulic piston, the adjusting screw is screwed down to enable the bottom face of the hydraulic piston to be in contact with the clearance gauge, and then the nut is locked. The brake clearance may be adjusted first and then the exhaust valve clearance may be adjusted.

In order to ensure that the hydraulic piston of the exhaust valve brake can normally extend and maintain the state, the oil pressure at the inlet of the brake is required to be ensured to be more than or equal to 150KPa.

The brake support in the device is of a four-cylinder integrated type, each diesel engine is only provided with an integrated electric control hydraulic exhaust valve brake device, the material is HT200, the inner diameter of a brake oil inlet channel is 4mm, the inner diameter of a main oil channel is 5mm, and the outer diameter of the oil channel is 18mm.

The 4BK engine can send 69.4KW braking power when rated speed 2800rpm, the liter braking power is 18KW/L, exhaust backpressure is 182KPa this moment, satisfies the operation requirement.

The working process is as follows: the upper part of the rocker arm seat is fixed with an exhaust valve braking device by a bolt, and an oil duct is arranged in the braking device and is communicated with an engine oil channel on the rocker arm seat of the engine. A hydraulic piston is arranged at the top of each cylinder exhaust valve rocker arm (the position of an exhaust valve), when the exhaust valve is required to brake, an electromagnetic valve on a brake device is opened through an exhaust brake switch (in a cab), and engine pressure engine oil enters a brake main oil gallery through the electromagnetic valve. The main oil duct is communicated with the hydraulic piston at the upper part of the exhaust valve rocker arm of each cylinder on the braking device, and the hydraulic piston of each cylinder can extend for a section of stroke under the action of the engine oil pressure. Because the hydraulic piston extends out and presses the top of the front end of the rocker arm of the exhaust valve, the exhaust valve is prevented from being completely closed, and the additional control of the exhaust valve is realized.

The electric control hydraulic exhaust valve braking device is designed and developed according to the structure of the diesel engine, the design has great innovation, good use effect is obtained through test verification, and good economic benefit and social benefit are achieved.

Claims

1. The automatically controlled hydraulic pressure exhaust valve arresting gear of diesel engine includes: exhaust valve stopper support, preceding rocking arm seat, middle rocking arm seat, solenoid valve, hydraulic piston, exhaust valve rocking arm, stopper clearance adjusting screw, exhaust valve, plug, and bolt, nut, characterized by: a brake support (1) is fixed on a middle rocker arm seat (3) and a front rocker arm seat (4) through bolts (2), a brake oil inlet channel (5) is arranged at the front end of the brake support in the vertical direction and is communicated with a vertical oil channel (6) on the front rocker arm seat, high-pressure engine oil from an engine enters the brake support through the front rocker arm seat, an electromagnetic valve oil inlet channel (7) is horizontally arranged at the upper end of the brake oil inlet channel, an electromagnetic valve (8) is also arranged in the middle of the front end of the brake support and is communicated with an oil inlet (8-1) of the electromagnetic valve, an oil outlet (8-2) of the electromagnetic valve is communicated with an electromagnetic valve oil outlet channel (9) and a brake main oil channel (10), the main oil channel is communicated with hydraulic pistons (11) of cylinders, the main oil channel, the electromagnetic valve oil inlet channel and the electromagnetic valve oil outlet channel are blocked through a plug (12) arranged at the front end of the brake support, the internal oil channel of the brake is sealed, when an exhaust brake switch is opened, the electromagnetic valve communicates the oil inlet channel with the oil outlet channel and the hydraulic pistons of the engine enter the brake through the electromagnetic valve, the hydraulic pistons of the brake to push the hydraulic pistons to move down, so as to stop an exhaust valve (13) from pressing a front exhaust valve.

2. The electrically controlled hydraulic exhaust valve brake device of the diesel engine according to claim 1, characterized in that: and a brake clearance adjusting screw (16) is arranged at the upper part of the hydraulic piston in the brake bracket, the clearance between the hydraulic piston and the exhaust valve rocker arm is adjusted by the upward anticlockwise rotation or downward clockwise rotation of the adjusting screw, and the adjusting screw is fixed by a nut (15).

3. The electrically controlled hydraulic exhaust valve brake device of the diesel engine according to claim 1, characterized in that: the brake support is characterized in that three sections of large reinforcing ribs (1-1) are arranged in the horizontal direction between every two hydraulic piston holes in each cylinder at the top of the brake support and connected with each other, 9 bolt hole umbilicals (1-2) are arranged on the brake support, vertical middle reinforcing ribs (1-3) are arranged between every two bolt hole umbilicals in each cylinder, vertical small reinforcing ribs (1-4) are arranged between every two hydraulic piston holes in each cylinder and the bolt hole umbilicals, three sections of inner reinforcing ribs (1-5) are horizontally arranged on the back of the brake support, and the inner reinforcing ribs are vertically and cross-connected with the large reinforcing ribs, the middle reinforcing ribs and the small reinforcing ribs and penetrate through the 9 mounting bolt hole umbilicals to form a cross framework structure.