CN111828121A

CN111828121A - Internal combustion engine cylinder brake device

Info

Publication number: CN111828121A
Application number: CN202010823189.XA
Authority: CN
Inventors: 马振万
Original assignee: Individual
Current assignee: Individual
Priority date: 2020-08-17
Filing date: 2020-08-17
Publication date: 2020-10-27

Abstract

The invention relates to a cylinder brake device of an internal combustion engine, which comprises a rocker shaft; the air inlet rocker arm structure is rotatably arranged on the rocker arm shaft; the exhaust rocker arm structure comprises an exhaust valve bridge and an exhaust rocker arm assembly; the first brake rocker arm structure comprises a first brake rocker arm assembly, a second brake rocker arm assembly and a brake assembly, wherein the first brake rocker arm assembly comprises a first brake cam and a first brake rocker arm which is rotatably arranged on the rocker arm shaft; the first brake control valve component comprises a valve rod, is connected with the other end of the first brake rocker arm, can move up and down relative to the first brake rocker arm, and can move down to abut against the first exhaust valve under the action of high-pressure oil; the first elastic member keeps the valve rod moving upwards and having a tendency to have a gap with the top of the first exhaust valve. Therefore, the braking action of the first exhaust valve can be changed, the exhaust valve is opened in the compression stroke and the acting stage, high-pressure gas is discharged into the exhaust pipe, energy is released, the engine is changed into an air compressor absorbing energy, the kinetic energy and the potential energy of the whole vehicle are consumed, and the braking power is improved.

Description

Internal combustion engine cylinder brake device

Technical Field

The invention belongs to the technical field of exhaust braking of automotive engines, and particularly relates to an internal combustion engine cylinder braking device.

Background

With the continuous development of road transportation in China, various medium and heavy commercial automobiles enter the transportation field of different industries, and the safety in the transportation process is the first major thing of people. The braking performance of various medium and heavy commercial vehicles during transportation is very important, and the driving safety is not optimistic particularly when the vehicles are on a long downhill. When the driver is on a long downhill, the driver needs to frequently use the brake to brake and decelerate, so that the brake is overheated, and the braking efficiency of the brake is gradually reduced and fails. The long-gradient road is more serious when being added on a rugged mountain road, and a large water tank is arranged on the back of a medium-heavy commercial automobile for watering and forcibly cooling a brake hub, so that the severe consequence of fatigue cracking of the hub can be accelerated, and great threat can be certainly caused to the driving safety of the vehicle. Particularly in cold winter, the water which is used for watering the brake hub to carry out forced cooling flows to the ground to be frozen, and the serious potential safety hazard is directly caused to the running of vehicles behind.

At present, as the engine power of medium and heavy commercial automobiles is increasingly larger and the driving environment is also a very severe place, the requirement of driving and braking safety can not be met for the current engine braking power state, and therefore, the improvement of the engine braking power is a very important research subject.

In view of the above, chinese patent No. CN200910140029.9 (publication No. CN101624925B) discloses an internal combustion engine with an engine braking device and a valve lash compensation mechanism, wherein the internal combustion engine (1) has at least one combustion chamber from which exhaust gas can be discharged by means of at least one exhaust valve (3, 4). Furthermore, it comprises an engine brake device (2) having a hydraulic valve auxiliary control unit (19) which is integrated in a connecting mechanism (5, 6, 7) connecting the exhaust valve (3) to the camshaft and which holds the exhaust valve (3) in a temporarily open position when the engine brake device is actuated, and a hydraulic valve play compensation mechanism (37) for the exhaust valve (3, 4). The hydraulic valve clearance compensation device (37) is connected to a main oil circuit for supplying oil. The hydraulic valve auxiliary control unit (19) is connected to an auxiliary oil circuit which is provided in addition to the main oil circuit for the purpose of oil supply.

Although the structure of the braking device can improve the braking efficiency, the structure is complex, the failure rate is high, and meanwhile, the response time is long due to the complex structure, and the braking is not timely enough.

Disclosure of Invention

The invention aims to solve the technical problem of the prior art and provides an internal combustion engine cylinder braking device which is high in braking efficiency and simple in structure.

The technical scheme adopted by the invention for solving the technical problems is as follows: an in-cylinder brake device for an internal combustion engine, comprising

A rocker shaft;

the air inlet rocker arm structure is rotatably arranged on the rocker arm shaft;

an exhaust rocker arm structure comprising

The exhaust valve bridge comprises an exhaust valve bridge frame, two valves arranged on the exhaust valve bridge frame and two exhaust valve springs which respectively and correspondingly enable the two valves to keep upward moving trend, wherein the two valves are a first exhaust valve and a second exhaust valve respectively;

the exhaust rocker arm assembly comprises an exhaust cam and an exhaust rocker arm rotatably arranged on a rocker arm shaft, wherein one end of the exhaust rocker arm is connected with the exhaust cam, and the other end of the exhaust rocker arm is connected with the exhaust valve bridge;

characterized in that the braking device also comprises a first braking rocker arm structure, and the first braking rocker arm structure comprises

The first brake rocker arm assembly comprises a first brake cam and a first brake rocker arm rotatably mounted on the rocker arm shaft, the first brake rocker arm and the exhaust rocker arm are arranged at intervals along the axial direction of the rocker arm shaft, and one end of the first brake rocker arm is connected with the first brake cam;

a first brake control valve assembly comprising

The valve rod is connected with the other end of the first brake rocker arm, can move up and down relative to the first brake rocker arm and can move down to abut against the first exhaust valve under the action of high-pressure oil;

the first elastic piece acts on the valve rod to enable the valve rod to keep moving upwards and have the tendency of clearance with the top of the first exhaust valve.

In order to enable high-pressure oil to act on the valve stem in the event of braking, the first brake control valve assembly further comprises

The valve body is fixedly arranged in the first brake rocker arm, a first cavity and a second cavity which are communicated are formed in the valve body, an oil passing port which is communicated with the first cavity in a fluid mode is formed in the top of the valve body, the oil passing port of the valve body is communicated with an oil inlet on the rocker arm shaft in a fluid mode through an oil duct, and the valve rod is arranged in the second cavity in a vertically movable mode;

the plugging piece is positioned in the first cavity and is arranged at the oil passing port;

the second elastic piece acts on the plugging piece, so that the plugging piece keeps the trend of plugging the oil passing opening. Therefore, when the brake is performed, the blocking piece is acted by high-pressure oil, the oil passing opening is opened, and then the high-pressure oil enters the first chamber to push the valve rod to move downwards.

In order to facilitate the installation of the valve body and enable the valve rod to be well matched with the first exhaust valve, the other end of the first brake rocker arm is provided with an installation part, an accommodating cavity is arranged in the installation part, the valve body is arranged in the accommodating cavity, a first oil duct is arranged on the rocker shaft, a second oil duct is arranged on the first brake rocker arm, one end of the first oil duct is communicated with an oil inlet in a fluid mode, the other end of the first oil duct is communicated with a first end of the second oil duct in a fluid mode, a second end of the second oil duct extends into the accommodating cavity and is communicated with an oil outlet in a fluid mode, and the first oil duct and the second oil duct. Therefore, the oil way is short, and high-pressure oil can quickly flow into the valve body so as to brake in time.

In order to facilitate the valve rod to move downwards under the action of high-pressure oil, the valve rod comprises a transverse section and a vertical section connected with the bottom wall of the transverse section, the outer peripheral wall of the transverse section is adjacent to the inner peripheral wall of the second cavity, and the lower end of the vertical section can extend out of the accommodating cavity. Because the stressed area of the transverse section is larger, the valve rod is convenient to move downwards under stress. And a limiting ring which is positioned below the transverse section and can be abutted against the transverse section is arranged in the valve body, and when the transverse section is abutted against the limiting ring, the valve rod cannot continuously move downwards.

Because the valve is usually installed in the lower extreme of exhaust valve crane span structure, in order to make the valve rod can the application of force on first exhaust valve, first exhaust valve includes valve body and the connecting axle that links to each other with valve body's upper end, and the connecting axle is installed on the exhaust valve crane span structure, and the upper end of connecting axle is located the top of exhaust valve crane span structure to can offset with the lower extreme of vertical section.

In order to adjust the distance between the lower end of the valve rod and the first exhaust valve, the lower part of the accommodating cavity is provided with a check ring, the bottom of the valve body is provided with a limiting piece capable of abutting against the check ring, the first elastic piece is a spring, one end of the first elastic piece abuts against the transverse section, and the other end of the first elastic piece abuts against the limiting piece; and an adjusting screw with the lower end abutting against the top of the valve body is inserted into the mounting part and is locked on the mounting part through a locking nut. Therefore, the distance between the lower end of the valve rod and the first exhaust valve is adjusted by changing the installation depth of the adjusting screw.

In the process that high-pressure oil flows to the valve rod and flows back to the oil duct, the high-pressure oil needs to be exhausted, so that an exhaust hole is formed in the first brake rocker arm, one end of the exhaust hole penetrates through the peripheral wall of the first brake rocker arm, the other end of the exhaust hole is communicated with the second oil duct, and an exhaust part is connected to the exhaust hole in a threaded mode. Therefore, air and a small amount of high-pressure oil can flow out from a gap between the exhaust part and the exhaust hole, and after the high-pressure oil is discharged from the gap between the exhaust part and the exhaust hole, the high-pressure oil can be thrown onto other parts under the swinging action of the first brake rocker arm to lubricate other parts.

Preferably, the exhaust member is provided with a buffer hole to buffer high-pressure oil.

In order to ensure that the brake roller is tightly contacted with the first brake cam so that the first brake rocker arm swings under the driving of the first brake cam, the first brake rocker arm is connected with the first brake cam through the brake roller, and the brake roller keeps the trend of being contacted with the first brake cam under the action of a third elastic piece.

In order to further improve the braking efficiency, the intake rocker arm structure comprises

The air inlet rocker arm is rotatably arranged on the rocker arm shaft;

the intake valve bridge comprises an intake valve bridge connected with one end of the rocker shaft, two intake valves arranged on the intake valve bridge and intake valve springs respectively acting on the two intake valves to enable the corresponding intake valves to keep an upward movement trend, and the two intake valves are a first intake valve and a second intake valve respectively;

the braking device also comprises a second braking rocker arm structure which comprises

The second brake rocker arm assembly comprises a second brake cam and a second brake rocker arm which is rotatably arranged on the rocker arm shaft, the second brake rocker arm and the air inlet rocker arm are arranged at intervals along the axial direction of the rocker arm shaft, and one end of the second brake rocker arm is connected with the second brake cam;

a second brake control valve assembly comprising

The valve core is connected with the other end of the second brake rocker arm, can move up and down relative to the second brake rocker arm, and can move down to abut against the first inlet valve under the action of high-pressure oil;

and the fourth elastic element acts on the valve core to ensure that the valve core keeps moving upwards and has a tendency of having a gap with the top of the first air inlet valve. This corresponds to a four rocker arm configuration, the braking power will be higher.

Compared with the prior art, the invention has the advantages that: according to the invention, the first brake rocker arm assembly and the first brake control valve assembly are arranged, so that the brake action of one valve (a first exhaust valve) is changed, in a compression stroke stage (under the working condition of exhaust brake operation of an internal combustion engine), the exhaust valve is opened through the first brake cam, the first brake control valve assembly and the like, high-pressure gas is discharged into the exhaust pipe, energy is released, the engine is changed into an air compressor absorbing energy, the kinetic energy and the potential energy of the whole vehicle are consumed, and the brake power is improved; in the stage of ending air intake, the exhaust valve is opened again, high back pressure gas of the whole vehicle is flushed back into the cylinder, and the braking power is further improved; in addition, the first brake control valve assembly comprises the valve rod and the first elastic piece, so that the structure is relatively simple, and the failure rate is low.

Drawings

FIG. 1 is a schematic structural view of example 1 of the present invention;

fig. 2 is a cross-sectional view of fig. 1 (with a gap between the valve stem and the connecting shaft);

FIG. 3 is a cross-sectional view of FIG. 1 (with the valve stem abutting the connecting shaft);

FIG. 4 is a cross-sectional view of the first brake control valve assembly of FIG. 2;

fig. 5 is a schematic structural diagram of embodiment 2 of the present invention.

Detailed Description

The invention is described in further detail below with reference to the accompanying examples.

As shown in fig. 1 to 4, the internal combustion engine cylinder braking device of the preferred embodiment includes a rocker shaft 1, an intake rocker arm structure, an exhaust rocker arm structure and a first braking rocker arm structure, where the exhaust rocker arm structure includes an exhaust valve bridge and an exhaust rocker arm assembly, the first braking rocker arm structure includes a first braking rocker arm assembly and a first braking control valve assembly, and the rocker shaft 1 is located on one side of the exhaust valve bridge.

The exhaust valve bridge comprises an exhaust valve bridge frame 21, two valves arranged on the exhaust valve bridge frame 21 and two exhaust valve springs 23 which respectively enable the two valves to keep upward moving trend, wherein the two valves are a first exhaust valve 221 and a second exhaust valve 222 respectively, and each valve is movably inserted into a valve seat ring 24.

The exhaust rocker arm assembly comprises an exhaust cam (not shown in the figure) and an exhaust rocker arm 3 rotatably mounted on a rocker shaft 1, wherein one end of the exhaust rocker arm 3 is connected with the exhaust cam so as to be capable of swinging, the other end of the exhaust rocker arm 3 is connected with an exhaust valve bridge 21, in the embodiment, the exhaust rocker arm 3 is connected with the exhaust valve bridge 21 through a valve adjusting bolt 31 and a elephant foot 32, the elephant foot 32 is arranged on the exhaust valve bridge 21, the valve adjusting bolt 31 is inserted on the exhaust rocker arm 3 and is fixed through a nut 33, and the valve adjusting bolt 31 and the elephant foot 32 are connected through a ball head structure, which is the.

The first brake rocker arm assembly comprises a first brake cam 4 and a first brake rocker arm 5 rotatably mounted on the rocker arm shaft 1, the first brake rocker arm 5 and the exhaust rocker arm 3 are arranged at intervals along the axial direction of the rocker arm shaft 1, one end of the first brake rocker arm 5 is connected with the first brake cam 4, the other end of the first brake rocker arm is connected with a first brake control valve assembly, and the first brake control valve assembly comprises a valve rod 61, a first elastic piece 62, a valve body 63, a blocking piece 64 and a second elastic piece 65.

The other end of the first brake rocker arm 5 is provided with a mounting portion 51, a containing cavity 52 is arranged in the mounting portion 51, the valve body 63 is fixedly arranged in the containing cavity 52, a sealing ring 633 is arranged between the valve body 63 and the side wall of the containing cavity 52, and the sealing ring 633 plays roles of damping and sealing.

The valve body 63 has a first chamber 631 and a second chamber 634 communicated with each other inside, the top of the valve body 63 is provided with an oil passing port 632 in fluid communication with the first chamber 631, the oil passing port 632 of the valve body 63 is in fluid communication with an oil inlet 10 on the rocker arm shaft 1 through oil passages, in this embodiment, the rocker arm shaft 1 is provided with a first oil passage 11, the first brake rocker arm 5 is provided with a second oil passage 53, one end of the first oil passage 11 is in fluid communication with the oil inlet 10, and the other end of the first oil passage 11 can be in fluid communication with a first end of the second oil passage 53 (in the case of braking, the first brake rocker arm 5 swings to a position where the first oil passage 11 is in fluid communication with the second oil passage 53), a second end of the second oil passage 53 extends into the accommodating cavity 52 and is in fluid communication with the oil passing port 632, and the first oil passage.

The blocking piece 64 is spherical and located in the first chamber 631, the blocking piece 64 is disposed at the oil passing opening 632, and the second elastic piece 65 acts on the blocking piece 64 to keep the blocking piece 64 in a tendency of blocking the oil passing opening 632. Thus, when braking, the blocking member 64 is acted on by high pressure oil, which opens the oil through hole 632, and then enters the first chamber 631. In this embodiment, the second elastic member 65 is a spring, and two ends of the spring respectively abut against the blocking member 64 and a positioning member 66 fixed relative to the valve body 63.

The valve rod 61 can be arranged in the second cavity 634 in a vertically movable manner, the first exhaust valve 221 is located below the valve rod 61, the first exhaust valve 221 comprises a valve body 2211 and a connecting shaft 2212 connected with the upper end of the valve body 2211, the connecting shaft 2212 is fixedly installed on the exhaust valve bridge 21, the upper end of the connecting shaft 2212 is located above the exhaust valve bridge 21, and the upper end of the connecting shaft 2212 can abut against the lower end of the valve rod 61.

After the high pressure oil enters the first chamber 631 of the valve body 63 from the oil through port 632, the valve rod 61 can move downward to abut against the upper end of the connecting shaft 2212 under the action of the high pressure oil, and the valve rod 61 keeps moving upward to have a tendency of clearance with the top of the first exhaust valve 221 under the action of the first elastic member 62.

In this embodiment, the valve rod 61 includes a transverse section 611 and a vertical section 612 connected to the bottom wall of the transverse section 611, the outer peripheral wall of the transverse section 611 is adjacent to the inner peripheral wall of the second chamber 634, and the lower end of the vertical section 612 can extend out of the accommodating cavity 52. The structural design of the valve rod 61 has the advantages that: because the force-bearing area of the transverse section 611 is large, the valve rod 61 is forced to move downwards conveniently. The valve body 63 is provided with a limiting ring 68 below the transverse section 611, and when the transverse section 611 abuts against the limiting ring 68, the valve rod 61 moves to the lower limit position.

The lower part of the accommodating cavity 52 is provided with a retaining ring 54, the bottom of the valve body 63 is provided with a limiting member 67 which can abut against the retaining ring 54, the vertical section 612 can penetrate through the limiting member 67, the first elastic member 62 is a spring, one end of the first elastic member abuts against the transverse section 611, and the other end of the first elastic member abuts against the limiting member 67. An adjusting screw 55 with the lower end abutting against the top of the valve body 63 is inserted into the mounting portion 51, and the adjusting screw 55 is locked to the mounting portion 51 by a lock nut 56. Thus, by changing the installation depth of the adjustment screw 55, the distance between the lower end of the valve stem 61 and the first exhaust valve 221 is adjusted.

When high-pressure oil flows to the first chamber 631, air is contained in the high-pressure oil, so that exhaust is required, in addition, in the process that the high-pressure oil flows back to the oil passage from the valve body 63, if the electromagnetic valve does not have an oil drainage structure, pressure is not released in the backflow process, so that the valve rod 61 moves up slowly, an exhaust hole 57 is formed in the first brake rocker arm 5, one end of the exhaust hole 57 penetrates through the outer peripheral wall of the first brake rocker arm 5, the other end of the exhaust hole 57 is communicated with the second oil passage 53, an exhaust member 58 is connected in the exhaust hole 57 in a threaded manner, and a buffer hole 581 is formed in the exhaust member 58. When the high-pressure oil flows into the first chamber 631 along the oil passage, a part of the oil flows into the buffer hole 581, because a gap is inevitably formed at the threaded connection between the exhaust member 58 and the exhaust hole 57, air in the high-pressure oil and a part of the oil in the buffer hole 581 flow out of the exhaust hole 57 along the gap between the exhaust member 58 and the exhaust hole 57, and another part of the oil in the buffer hole 581 continues to flow into the oil return passage toward the valve body 63;

when the high-pressure oil in the valve body 63 flows back towards the oil inlet 10 along the oil passage, a small part of the high-pressure oil can also leak out from the gap between the exhaust part 58 and the exhaust hole 57, so that the purpose of pressure relief is achieved;

further, after the high-pressure oil leaks from the gap between the exhaust port 58 and the exhaust hole 57, the high-pressure oil is thrown to other components by the swinging action of the first brake rocker arm 5, and the other components can be lubricated.

First braking rocking arm 5 passes through brake roller 59 and links to each other with first brake cam 4, is equipped with locating rack 71 above first braking rocking arm 5, is equipped with third elastic component 7 between locating rack 71 and the first braking rocking arm 5, and third elastic component 7 is the spring, and both ends are supported respectively and are leaned on locating rack 71 and first braking rocking arm 5, make brake roller 59 remain the trend that contacts with first brake cam 4 all the time to make first braking rocking arm 5 swing under the drive of first brake cam 4.

If the first brake rocker arm 5 is made of steel, a bushing 8 may be disposed between the rocker shaft 1 and the first brake rocker arm 5, and the oil passage penetrates through the bushing 8, but the bushing 8 may not be disposed if other materials with good friction pair are used.

The intake rocker arm structure a of the present embodiment adopts a structure of the prior art, and includes an intake cam (not shown in the figure), an intake rocker arm 91 and an intake valve bridge, where the intake valve bridge includes an intake valve bridge 92 connected to one end of a rocker arm shaft 1, two intake valves mounted on the intake valve bridge 92, and an intake valve spring 95 acting on the two intake valves respectively to keep the corresponding intake valves moving upward, the two valves are a first intake valve 93 and a second intake valve 94, the intake rocker arm 91 is rotatably mounted on the rocker arm shaft 1 and is arranged at an interval with an exhaust rocker arm, one end of the intake rocker arm 91 is connected to the intake cam to be able to swing, and the other end of the intake rocker arm 91 is connected to the intake valve bridge 92.

The operation of the braking device of the embodiment is as follows:

under the working condition of normal operation of the internal combustion engine:

the intake rocker arm structure and the exhaust rocker arm structure operate in a normal state.

The first braking rocker arm 5 operates according to the profile track of the first braking cam 4 under the action of the first braking cam 4, and at the moment, because no high-pressure oil enters the oil duct, in this state, the valve rod 61 is not in contact with the connecting shaft 2212 of the first exhaust valve 221, and the normal operation of the structure of the exhaust rocker arm is not influenced.

Under the working condition of the exhaust brake operation of the internal combustion engine:

the intake rocker arm structure and the exhaust rocker arm structure still operate in a normal state.

As shown in fig. 3, when the internal combustion engine needs to perform exhaust braking operation, high-pressure oil of the internal combustion engine sequentially passes through the oil inlet 10, the oil passage and the oil through port 632 of the rocker shaft 1 (in the process, part of the high-pressure oil rapidly flows to the exhaust hole 57, and part of the air is exhausted from the gap between the exhaust member 58 and the exhaust hole 57), and then the opening block 64 is opened to enter the first chamber 631, under the action of high-pressure oil, the valve rod 61 moves down rapidly to the lower limit position against the limit ring 68, the first elastic element 62 is in a compressed state, and this operation state is continuously established, the valve stem 61 forces the first exhaust valve 221 to move down, so that the first exhaust valve 221 operates according to the double-lap type line locus of the exhaust cam and the first brake cam 4 (i.e., is simultaneously acted by the exhaust cam and the first brake cam 4), and enters a brake operation state.

Under the working condition of releasing the exhaust braking operation of the internal combustion engine:

As shown in fig. 2, when the internal combustion engine cuts off the high-pressure oil entering the first braking rocker arm 5, the high-pressure oil will leak downwards in the gap between the valve rod 61 and the valve body 63, and at the same time, because the first braking rocker arm 5 is in continuous swing operation, the blocking member 64 in the valve body 63 will slightly move under the action of gravity to open the oil through port 632 to a smaller opening degree, so that part of the high-pressure oil will be discharged from the oil through port 632, through the oil duct, the exhaust hole 57 and the oil discharge hole of the solenoid valve, the first exhaust valve 221 will move upwards under the action of the corresponding exhaust valve spring 23, the valve rod 61 will be pushed upwards, and the valve rod 61 will return upwards under the action of the first elastic member 62 at the same time until the top of the valve rod 61 abuts against the top wall of the second chamber 634, at this time, the connecting shaft 2212 and the valve rod 61 will maintain the original gap, and the first braking rocker arm structure will still operate as it, the working condition of the exhaust braking operation of the internal combustion engine is relieved.

This embodiment is equivalent to having three rocker arm structures: a first brake rocker arm structure, an intake rocker arm structure, and an exhaust rocker arm structure.

Example 2

Example 2 differs from example 1 in that: be provided with second braking rocker arm structure A, the structure of second braking rocker arm structure is the same with the structure of first braking rocker arm structure completely, and the difference lies in: the second brake rocker arm structure is matched with the air inlet rocker arm structure, a valve core in the second brake rocker arm assembly is equivalent to a valve rod in the first brake rocker arm assembly, and a fourth elastic piece in the second brake rocker arm assembly is equivalent to a first elastic piece in the first brake rocker arm assembly.

In other words, the second brake rocker arm assembly and the first brake rocker arm assembly have the same structure, the second brake control valve assembly and the first brake control valve assembly have the same structure, the second brake rocker arm assembly and the second brake control valve assembly are matched in the same way as the first brake rocker arm assembly and the first brake control valve assembly, the second brake control valve assembly and the first intake valve are matched in the same way as the first brake control valve assembly and the first exhaust valve, but the cam profile of the first brake cam and the cam profile of the second brake cam are different, and therefore, the description is omitted, and reference may be made to example 1.

This embodiment is equivalent to having four rocker arm structures: the brake system comprises a first brake rocker arm structure, a second brake rocker arm structure, an air inlet rocker arm structure and an exhaust rocker arm structure.

Claims

1. An in-cylinder brake device for an internal combustion engine, comprising

A rocker shaft (1);

the air inlet rocker arm structure is rotatably arranged on the rocker arm shaft (1);

an exhaust rocker arm structure comprising

The exhaust valve bridge comprises an exhaust valve bridge frame (21), two valves arranged on the exhaust valve bridge frame (21) and two exhaust valve springs (23) which respectively and correspondingly enable the two valves to keep upward moving trend, wherein the two valves are a first exhaust valve (221) and a second exhaust valve (222);

the exhaust rocker arm assembly comprises an exhaust cam and an exhaust rocker arm (3) rotatably mounted on a rocker arm shaft (1), one end of the exhaust rocker arm (3) is connected with the exhaust cam, and the other end of the exhaust rocker arm is connected with an exhaust valve bridge (21);

the method is characterized in that: the braking device further comprises a first braking rocker arm structure, and the first braking rocker arm structure comprises

The first brake rocker arm assembly comprises a first brake cam (4) and a first brake rocker arm (5) rotatably mounted on the rocker arm shaft (1), the first brake rocker arm (5) and the exhaust rocker arm (3) are axially arranged along the rocker arm shaft (1) at intervals, and one end of the first brake rocker arm (5) is connected with the first brake cam (4);

a first brake control valve assembly comprising

The valve rod (61) is connected with the other end of the first brake rocker arm (5), can move up and down relative to the first brake rocker arm (5), and can move down to abut against the first exhaust valve (221) under the action of high-pressure oil;

and a first elastic member (62) acting on the valve rod (61) to keep the valve rod (61) moving upwards and having a tendency to have a gap with the top of the first exhaust valve (221).

2. The in-cylinder brake apparatus for an internal combustion engine according to claim 1, characterized in that: the first brake control valve assembly further comprises

The valve body (63) is fixedly arranged in the first brake rocker arm (5), a first cavity (631) and a second cavity (634) which are communicated with each other are formed in the valve body (63), an oil passing port (632) which is communicated with the first cavity (631) in a fluid mode is formed in the top of the valve body (63), the oil passing port (632) of the valve body (63) is communicated with an oil inlet (10) in the rocker arm shaft (1) in a fluid mode through an oil duct, and the valve rod (61) can be arranged in the second cavity (634) in a vertically moving mode;

the blocking piece (64) is positioned in the first chamber (631) and arranged at the oil passing port (632);

and the second elastic piece (65) acts on the blocking piece (64) to ensure that the blocking piece (64) keeps the tendency of blocking the oil passing hole (632).

3. The in-cylinder brake apparatus for an internal combustion engine according to claim 2, characterized in that: the other end of first braking rocking arm (5) has installation department (51), be equipped with holding chamber (52) in installation department (51), valve body (63) are located in this holding chamber (52), be equipped with first oil duct (11) on rocking arm axle (1), be equipped with second oil duct (53) on first braking rocking arm (5), first oil duct (11) one end and oil inlet (10) fluid intercommunication, the other end can with the first end fluid intercommunication of second oil duct (53), the second end of second oil duct (53) extend to in holding chamber (52) and with cross hydraulic fluid intercommunication of hydraulic fluid port (632), first oil duct (11) and second oil duct (53) constitute jointly the oil duct.

4. The in-cylinder brake device for an internal combustion engine according to claim 3, characterized in that: the valve rod (61) comprises a transverse section (611) and a vertical section (612) connected with the bottom wall of the transverse section (611), the outer peripheral wall of the transverse section (611) is adjacent to the inner peripheral wall of the second chamber (634), and the lower end of the vertical section (612) can extend out of the accommodating cavity (52); and a limiting ring (68) which is positioned below the transverse section (611) and can be abutted against the transverse section (611) is arranged in the valve body (63).

5. The in-cylinder brake device for an internal combustion engine according to claim 4, characterized in that: the first exhaust valve (221) comprises a valve body (2211) and a connecting shaft (2212) connected with the upper end of the valve body (2211), the connecting shaft (2212) is mounted on the exhaust valve bridge (21), the upper end of the connecting shaft (2212) is located above the exhaust valve bridge (21), and the upper end of the connecting shaft (2212) can abut against the lower end of the vertical section (612).

6. The in-cylinder brake device for an internal combustion engine according to claim 4, characterized in that: a retaining ring (54) is arranged at the lower part of the accommodating cavity (52), a limiting piece (67) capable of abutting against the retaining ring (54) is arranged at the bottom of the valve body (63), the first elastic piece (62) is a spring, one end of the first elastic piece abuts against the transverse section (611), and the other end of the first elastic piece abuts against the limiting piece (67); and an adjusting screw (55) with the lower end abutting against the top of the valve body (63) is inserted into the mounting part (51), and the adjusting screw (55) is locked on the mounting part (51) through a locking nut (56).

7. The in-cylinder brake apparatus for an internal combustion engine according to claim 1, characterized in that: exhaust hole (57) has been seted up on first brake rocking arm (5), exhaust hole (57) one end link up the periphery wall of first brake rocking arm (5), and the other end is linked together with second oil duct (53), threaded connection has exhaust piece (58) in exhaust hole (57).

8. The in-cylinder brake apparatus for an internal combustion engine according to claim 7, characterized in that: the exhaust member (58) is provided with a buffer hole (581).

9. The in-cylinder brake apparatus for an internal combustion engine according to claim 1, characterized in that: the first braking rocker arm (5) is connected with the first braking cam (4) through a braking roller (59), and the braking roller (59) keeps the trend of contacting with the first braking cam (4) under the action of a third elastic member (7).

10. The in-cylinder brake device for an internal combustion engine according to any one of claims 1 to 9, wherein: the intake rocker arm structure comprises

The air inlet rocker arm is rotatably arranged on the rocker arm shaft;

a second brake control valve assembly comprising

and the fourth elastic element acts on the valve core to ensure that the valve core keeps moving upwards and has a tendency of having a gap with the top of the first air inlet valve.