Internal combustion engine cylinder braking device

Abstract

The present invention relates to an internal combustion engine cylinder brake device, comprising an exhaust valve bridge, on which an exhaust valve is installed; a rocker arm, one end of which is connected to a cam; a valve adjustment bolt, the upper end of which is connected to the other end of the rocker arm, and the lower end of which is connected to a mounting seat located above the exhaust valve bridge through a ball head structure; a movable seat, which is arranged in the exhaust valve bridge and can move up and down relatively to each other, and the movable seat maintains a tendency to abut against the lower end surface of the mounting seat under the action of a fourth elastic member; an oil channel, which can switchably connect a lubricating oil inlet or a high-pressure oil inlet with the rocker arm, the valve adjustment bolt, the mounting seat, the movable seat and finally the exhaust valve bridge in sequence; an elastic valve stem driven by the fourth elastic member; a stroke limiting component, which is arranged on the cylinder head; when the cylinder brake takes effect, the movable seat moves upward, the exhaust valve bridge moves downward, the lower part of the elastic valve stem abuts against the stroke limiting component, and the elastic valve stem opens the outlet to leak high-pressure oil, thereby improving the accuracy and reliability of the exhaust valve clearance.

Description

Technical Field

[0001] The invention belongs to the technical field of vehicle engine exhaust brake, and in particular relates to an in-cylinder brake device for an internal combustion engine. Background Art

[0002] With the continuous development of my country's road transportation, various medium and large passenger cars, medium and heavy commercial vehicles have entered the transportation field of different industries. Safety during transportation is our top priority. The braking performance of automobiles during transportation is very important, especially when driving on a long downhill slope, the driving safety is even more not optimistic. Because on a long downhill slope, the driver has to frequently use the brakes to brake and slow down, which causes the brakes to overheat, causing the brake efficiency to gradually decrease and fail. The situation is more serious on rugged mountain roads with long slopes. Some medium and heavy commercial vehicles use a large water tank to force cooling of the brake hubs. This will accelerate the serious consequences of fatigue cracking of the hubs, which will directly threaten the safety of vehicle driving. Especially in the cold winter, the brake hubs are forced to cool by water, and the cooling water flows to the ground and freezes, which directly causes major safety hazards to the driving and life of the vehicles behind.

[0003] In order to ensure the safety of medium and large passenger cars, medium and heavy commercial vehicles on long downhill and rugged mountain roads, and to improve transportation conditions, although there are many braking methods, in order to take into account the reliability, safety and economy of braking of moving vehicles, it is urgent to explore and seek the optimal solution for internal combustion engine cylinder braking.

[0004] In response to the above problems, the Chinese utility model patent with patent number CN200820018742.7 (publication number CN201184224Y) discloses the "Exhaust Valve Braking Device for Four-Valve Engine", which includes an exhaust valve, an exhaust valve bridge, a rocker arm structure installed on the cylinder head for opening the exhaust valve, a power device fixed below the rocker arm structure for driving the rocker arm structure to rotate, a valve adjustment bolt assembly located above the exhaust valve bridge for sealing and draining oil, and a cylinder block and cylinder head oil passage. The braking device reduces the work done by the gas in the combustion chamber on the piston by controlling the exhaust valve to remain open, improves the braking power, and reduces the speed of the entire vehicle; it helps to reduce the speed of the vehicle when it is going downhill for a long time.

[0005] However, the structure of the brake device can only improve the braking efficiency. During the use of the internal combustion engine, problems such as noise caused by gaps and high-pressure oil impacting the exhaust valve bridge due to air in the oil channel are also important issues that plague designers. Summary of the invention

[0006] The first technical problem to be solved by the present invention is to provide an internal combustion engine cylinder brake device which improves the braking effect by causing a small amount of brake high-pressure oil to leak in response to the current status of the prior art.

[0007] The second technical problem to be solved by the present invention is to provide an internal combustion engine cylinder brake device which can reduce the gap to reduce the noise in view of the current status of the prior art.

[0008] The third technical problem to be solved by the present invention is to provide an in-cylinder brake device for an internal combustion engine without air in the oil passage in view of the current status of the prior art.

[0009] The technical solution adopted by the present invention to solve the above three technical problems is: an internal combustion engine cylinder brake device, comprising

[0010] an exhaust valve bridge on which exhaust valves are mounted;

[0011] A rocker arm, one end of which is connected to the cam;

[0012] The valve adjustment bolt has an upper end connected to the other end of the rocker arm, and a lower end connected to a mounting seat located above the exhaust valve bridge through a ball head structure;

[0013] It is characterized by that it also includes

[0014] A movable seat is arranged in the exhaust valve bridge and can move up and down relatively to each other, and the movable seat maintains a tendency to abut against the lower end surface of the mounting seat under the action of a fourth elastic member;

[0015] The oil passage can switchably connect the lubricating oil inlet or the high-pressure oil inlet with the rocker arm, the valve adjustment bolt, the mounting seat, the movable seat and the exhaust valve bridge in sequence;

[0016] An elastic valve stem driven by a fourth elastic member is disposed in the exhaust valve bridge and extends downward through an outlet of the oil passage;

[0017] The stroke limit component is arranged on the cylinder head. When the cylinder brake takes effect, the movable seat moves upward, the exhaust valve bridge moves downward, the lower part of the elastic valve stem contacts the stroke limit component, and the elastic valve stem opens the outlet to leak high-pressure oil.

[0018] In order to enable the oil passage to switchably connect the lubricating oil inlet or the high-pressure oil inlet with the rocker arm, the valve adjustment bolt, the mounting seat, the movable seat and finally the exhaust valve bridge in sequence, the oil passage includes a first oil passage arranged on the rocker arm, two second oil passages for respectively supplying the lubricating oil and the high-pressure oil to flow into the first oil passage, and a third oil passage that passes through the valve adjustment bolt and the mounting seat in sequence, and a fourth oil passage that passes through the movable seat and the bottom of the exhaust valve bridge in sequence. When one of the second oil passages is fluidically connected to the first oil passage, the other second oil passage is disconnected from the first oil passage, and the third oil passage is connected between the first oil passage and the fourth oil passage.

[0019] In order to enable the elastic valve stem to open and close the outlet, the elastic valve stem includes a limit rod movably arranged in the outlet of the fourth oil channel and a shielding portion radially formed on the upper end of the limit rod, the shielding portion is located in the fourth oil channel and can shield the outlet, and the travel limit component is a column arranged below the exhaust valve bridge and can abut against the lower end of the limit rod. In this way, when the exhaust valve bridge moves downward and the limit rod and the column abut against each other, the exhaust valve bridge continues to move downward for a very small stroke, and the limit rod will move slightly upward relative to the exhaust valve bridge, so that the outlet has a smaller opening, so that a small amount of brake high-pressure oil leaks from the outlet; and when the pressure decreases or disappears, the exhaust valve bridge moves upward under the action of the valve spring, the outlet will be shielded by the shielding portion again, and the exhaust valve bridge continues to move upward, which will drive the elastic valve stem to move upward accordingly.

[0020] From the foregoing, it can be seen that the structural design of the braking device is ingenious and reasonable. When the exhaust valve bridge moves upward, the outlet of the fourth oil channel can be automatically closed by the elastic valve stem, and there is no need to set a driving component that drives the elastic valve stem to close the outlet, so fewer components are involved; and the stroke limit component is a column, which has a simple structure.

[0021] In order to ensure that the lubricating oil or brake high-pressure oil entering the third oil channel can only flow into the fourth oil channel and cannot flow back from the fourth oil channel to the third oil channel, the movable seat is provided with a first one-way valve located in the fourth oil channel, the first one-way valve includes a U-shaped first valve seat, a first valve ball arranged in the first valve seat, and a first elastic member acting on the first valve ball, the first valve ball is arranged adjacent to the inlet of the fourth oil channel, and the first elastic member enables the first valve ball to maintain a tendency to cover the inlet.

[0022] In order to facilitate the setting of the fourth elastic member and enable the force exerted by the fourth elastic member to act directly or indirectly on the movable seat, a limit groove is provided on the inner wall of the movable seat, and a limit flange that can resist the top wall and bottom wall of the limit groove is formed on the outer wall of the first valve seat. The fourth elastic member is a spring, one end of which resists the elastic valve stem and the other end resists the limit flange; the fourth elastic member can also play the role of enabling the elastic valve stem to cover the opening of the fourth oil channel.

[0023] In order to disconnect the other second oil passage from the first oil passage when one of the second oil passages is in fluid communication with the first oil passage, the two second oil passages are respectively a lubricating oil passage in fluid communication with the lubricating oil inlet and a high-pressure oil passage in fluid communication with the high-pressure oil inlet, a second one-way valve is provided between the first oil passage and the lubricating oil passage to allow only lubricating oil to flow from the lubricating oil passage to the first oil passage, and a third one-way valve is provided between the first oil passage and the high-pressure oil passage to allow only high-pressure oil to flow from the high-pressure oil passage to the first oil passage. In this way, when the lubricating oil flows into the first oil passage, due to the action of the third one-way valve, there is no high-pressure oil at this time, and the lubricating oil will not flow into the high-pressure oil passage; when the high-pressure oil flows into the first oil passage, due to the action of the second one-way valve, the lubricating oil cannot flow into the first oil passage.

[0024] The second one-way valve can have various structural forms. Preferably, the second one-way valve includes a second valve body arranged on the rocker arm, the second valve body is provided with a second channel connecting the lubricating oil channel and the first oil channel, the second channel is provided with a second valve seat, a second valve ball arranged in the second valve seat, and a second elastic member acting on the second valve ball, the second elastic member enables the second valve ball to maintain a tendency to block the port of the second channel close to the lubricating oil channel.

[0025] The third one-way valve can have various structural forms. Preferably, the third one-way valve includes a third valve body arranged on the rocker arm, and the third valve body is provided with a third channel connecting the high-pressure oil channel and the first oil channel. A third valve ball and a third elastic member acting on the third valve ball are arranged in the third channel, and the third elastic member enables the third valve ball to maintain a tendency to block the port of the third channel close to the high-pressure oil channel.

[0026] In order to facilitate the entry of lubricating oil or high-pressure oil, the rocker arm is arranged on the rocker arm shaft, and the rocker arm shaft is provided with a lubricating oil inlet fluidly connected to the lubricating oil channel and a high-pressure oil inlet fluidly connected to the high-pressure oil channel.

[0027] Preferably, a bushing is provided between the rocker arm and the rocker arm shaft, and the bushing is provided with a first through hole connecting the lubricating oil inlet and the lubricating oil channel, and a second through hole connecting the high-pressure oil inlet and the high-pressure oil channel. A bushing is required for a steel rocker arm, and this rocker arm bushing may not be used if other materials with good friction performance are used.

[0028] In order to make the movable seat and the exhaust valve bridge cooperate well, a movable seat hole is provided on the exhaust valve bridge, and the movable seat can be movably arranged in the movable seat hole, and the movable seat hole is connected with the oil channel located on the exhaust valve bridge.

[0029] The structure is simple, the lower end of the valve adjustment bolt is a ball head structure, and the mounting seat is provided with a ball socket adapted to the ball head structure. In this way, the ball head structure is directly formed on the valve adjustment bolt without being separately provided.

[0030] Compared with the prior art, the advantages of the present invention are as follows: 1. The brake device of the present invention is provided with an elastic valve stem capable of blocking or opening the outlet of the fourth oil channel. When the brake high-pressure oil enters the oil channel and the exhaust valve bridge moves downward under the pressure of the high-pressure oil, the elastic valve stem can open the outlet to a smaller opening, thereby causing a small amount of brake high-pressure oil to leak, thereby improving the accuracy and reliability of the exhaust valve clearance. In this way, by changing the action of the engine exhaust valve, when the compression stroke is about to end, the exhaust valve is opened to discharge high-pressure gas into the exhaust pipe, releasing energy, turning the engine into an energy-absorbing air compressor, consuming the kinetic energy and potential energy of the entire vehicle, and the internal combustion engine brakes in a compression-release manner, thereby greatly improving and improving the braking reliability, safety and economy of the moving vehicle; in addition, the exhaust valve can be opened again at the end of the intake to recoil the high back-pressure gas (air during braking) of the entire vehicle into the cylinder, thereby further improving the braking power;

[0031] 2. Because the lubricating oil fills the gap inside the movable seat, the gap is overcome, and the movable seat maintains a tendency to abut against the lower end surface of the mounting seat under the elastic action of the fourth elastic member, and the mounting seat is connected to the valve adjustment bolt, so that there is no gap between the mounting seat and the movable seat, and if there is a gap between the cam and the rocker arm, the rocker arm will also swing slightly under the action of the force applied by the movable seat to the mounting seat to overcome the gap. In this way, under normal operating conditions of the internal combustion engine, the valve clearance is extremely small (almost to zero clearance), which reduces the noise of the entire transmission chain of the rocker arm mechanism, improves the NVH performance, and also increases the service life of the entire transmission chain parts of the rocker arm mechanism of the internal combustion engine.

[0032] 3. When the internal combustion engine is in exhaust brake operation, the entire oil channel is filled with lubricating oil before switching to the brake operation condition. When the oil channel quickly enters the brake high-pressure oil (except the lubricating oil channel and the second one-way valve), in this state, there is no air in the entire oil channel (air is compressible), so the brake high-pressure oil will not instantly impact the exhaust valve bridge, which also improves the timeliness, reliability and safety of exhaust brake.

[0033] It can be seen from the above that the brake device of the present invention can achieve the above effects while satisfying the normal exhaust brake function. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 It is a structural schematic diagram of an embodiment of the present invention;

[0035] Figure 2 for Figure 1Schematic diagram of the oil circuit (under the exhaust brake operating condition of the internal combustion engine);

[0036] Figure 3 for Figure 1 Schematic diagram of the oil circuit (under normal operating conditions of the internal combustion engine);

[0037] Figure 4 for Figure 1 A schematic diagram of the structure of the exhaust valve bridge, the first one-way valve, and the movable seat;

[0038] Figure 5 for Figure 1 A schematic diagram of the structure of the second one-way valve in FIG.

[0039] Figure 6 for Figure 1 Schematic diagram of the structure of the third one-way valve in FIG. DETAILED DESCRIPTION

[0040] The present invention is further described in detail below with reference to the accompanying drawings.

[0041] like Figures 1 to 6 As shown, the in-cylinder braking device of an internal combustion engine of this preferred embodiment can be applied to an in-cylinder braking device of a two-valve or multi-valve structure, including an exhaust valve bridge 1, a rocker arm 2, a valve adjustment bolt 4, a movable seat 12, an oil channel, an elastic valve stem 5 and a stroke limit component 6.

[0042] The exhaust valve bridge 1 is equipped with an exhaust valve 11, which is movably inserted on the valve seat ring 111. The rocker arm 2 is arranged on the rocker arm shaft 24, and one end of the rocker arm 2 is connected to the cam 3 through the roller 26. The upper end of the valve adjustment bolt 4 is connected to the other end of the rocker arm 2 and fixed by a nut 43, and the lower end is connected to the mounting seat 41 through a ball head structure. The mounting seat 41 is located above the exhaust valve bridge 1. This part is the prior art and will not be described in detail here. In this embodiment, the lower end of the valve adjustment bolt 4 is a ball head structure 44, and the mounting seat 41 is provided with a ball socket 411 adapted to the ball head structure.

[0043] A movable seat hole 14 is opened on the exhaust valve bridge 1, and the movable seat 12 can be movably arranged in the movable seat hole 14. The exhaust valve bridge 1 and the movable seat 12 can move up and down relatively, and the movable seat 12 maintains a tendency to move upward and resist the lower end surface of the mounting seat 41 under the action of the fourth elastic member 120.

[0044] The oil passages include a first oil passage 21, a second oil passage, a third oil passage 42 and a fourth oil passage 13. The second oil passages have two passages for supplying lubricating oil and high-pressure oil to flow into the first oil passage 21 respectively. When one of the second oil passages is fluidly connected to the first oil passage 21, the other second oil passage is disconnected from the first oil passage 21. The third oil passage 42 passes through the valve adjustment bolt 4 and the mounting seat 41 in sequence. The fourth oil passage 13 passes through the movable seat 12 and the bottom of the exhaust valve bridge 1 in sequence. The first oil passage 21 and the two second oil passages are all arranged on the rocker arm 2. The third oil passage 42 is connected between the first oil passage 21 and the fourth oil passage 13. The fourth oil passage 13 is connected to the movable seat hole 14.

[0045] In this embodiment, the two second oil passages are respectively a lubricating oil passage 22 and a high-pressure oil passage 23. The rocker arm shaft 24 is provided with a lubricating oil inlet 241 in fluid communication with the lubricating oil passage 22 and a high-pressure oil inlet 242 in fluid communication with the high-pressure oil passage 23. A second one-way valve 8 is provided between the first oil passage 21 and the lubricating oil passage 22, which only allows lubricating oil to flow from the lubricating oil passage 22 into the first oil passage 21. A one-way valve 8 is provided between the first oil passage 21 and the high-pressure oil passage 23, which only allows high-pressure oil to flow from the high-pressure oil passage 23 into the first oil passage 21. The third one-way valve 9 of the first oil passage 21, when the lubricating oil flows into the first oil passage 21, due to the action of the third one-way valve 9, there is no high-pressure oil at this time, and the lubricating oil will not flow into the high-pressure oil passage 23, so as to prevent the lubricating oil from leaking; when the high-pressure oil flows into the first oil passage 21 through the high-pressure oil passage 23, due to the action of the second one-way valve 8, the high-pressure oil will not flow into the lubricating oil passage 22 through the first oil passage 21, thereby realizing that when one of the second oil passages is fluidly connected with the first oil passage 21, the other second oil passage is disconnected from the first oil passage 21.

[0046] As can be seen from the above, the oil passage can switchably connect the lubricating oil inlet 241 or the high-pressure oil inlet 242 with the rocker arm 2, the valve adjustment bolt 4, the mounting seat 41, the movable seat 12 and the exhaust valve bridge 1 in sequence. In addition, the oil passages in this embodiment can be directly connected to each other or connected through other branch oil passages.

[0047] In this embodiment, the second one-way valve 8 includes a second valve body 81 arranged on the rocker arm 2, and a second channel 811 connecting the lubricating oil channel 22 and the first oil channel 21 is opened on the second valve body 81. A U-shaped second valve seat 80, a second valve ball 82 arranged in the second valve seat 80, and a second elastic member 83 acting on the second valve ball 82 are arranged in the second channel 811. The two ends of the second elastic member 83 respectively abut against the second valve seat 80 and the second valve ball 82, so that the second valve ball 82 maintains a tendency to block the port of the second channel 811 close to the lubricating oil channel 22.

[0048] The third one-way valve 9 includes a third valve body 91 arranged on the rocker arm 2, and a third channel 911 connecting the high-pressure oil channel 23 and the first oil channel 21 is opened on the third valve body 91. A third valve ball 92 and a third elastic member 93 acting on the third valve ball 92 are arranged in the third channel 911. The two ends of the third elastic member 93 respectively abut against the rocker arm 2 and the third valve ball 92, so that the third valve ball 92 keeps the tendency of blocking the port of the third channel 911 close to the high-pressure oil channel 23. The third channel 911 and the first oil channel 21 can be provided with an oil channel branch 27.

[0049] For the rocker arm 2 made of steel material, a bushing 25 needs to be provided between the rocker arm 2 and the rocker arm shaft 24. To ensure the connectivity of the oil passage, the bushing 25 is provided with a first through hole connecting the lubricating oil inlet 241 and the lubricating oil passage 22 and a second through hole connecting the high-pressure oil inlet 242 and the high-pressure oil passage 23.

[0050] A first one-way valve 7 located in the fourth oil passage 13 is provided in the movable seat 12. The first one-way valve 7 includes a U-shaped first valve seat 71, a first valve ball 72 provided in the first valve seat 71, and a first elastic member 73 acting on the first valve ball 72. The first valve ball 72 is provided adjacent to the inlet 132 of the fourth oil passage 13. The first elastic member 73 is a spring, and its two ends are respectively against the first valve seat 71 and the first valve ball 72, so that the first valve ball 72 maintains a tendency to cover the inlet 132, so that the lubricating oil or brake high-pressure oil entering the third oil passage 42 can only flow into the fourth oil passage 13, and cannot flow back from the fourth oil passage 13 to the third oil passage 42.

[0051] A limiting groove 121 is provided on the inner wall of the movable seat 12, and a limiting flange 711 that can abut against the top wall and bottom wall of the limiting groove 121 is formed on the outer wall of the first valve seat 71. The fourth elastic member 120 is a spring, one end of which abuts against the elastic valve stem 5, and the other end abuts against the limiting flange 711. When the first valve seat 71 abuts against the top wall of the limiting groove 121, the force of the fourth elastic member 120 acting on the first valve seat 71 will be transmitted to the movable seat 12, so that the movable seat 12 always maintains a tendency to abut against the mounting seat 41.

[0052] In this embodiment, the elastic valve stem 5 includes a limiting rod 51 movably inserted into the outlet 131 of the fourth oil channel 13 and a shielding portion 52 radially formed at the upper end of the limiting rod 51. The shielding portion 52 is located in the fourth oil channel 13 and can shield or open the outlet 131.

[0053] The stroke limit component 6 is a column arranged below the exhaust valve bridge 1 and can abut against the lower end of the limit rod 51. The column is arranged on the upper end surface 61 of the cylinder head. When the in-cylinder brake takes effect and the exhaust valve opening setting program is working, the exhaust valve bridge 1 moves downward, and the lower side of the elastic valve stem 5 abuts against the stroke limit component 6, and the elastic valve stem 5 opens the outlet 131 to leak high-pressure oil.

[0054] In other words, when the exhaust valve bridge 1 moves downward and the limit rod 51 and the stroke limit component 6 are in contact with each other, the exhaust valve bridge 1 continues to move downward a very small stroke. Because the stroke limit component 6 is a fixed part and will not move downward, a slight relative movement will occur between the exhaust valve bridge 1 and the elastic valve stem 5, which will cause the outlet 131 to be opened a very small degree, and a small amount of brake high-pressure oil will leak from the outlet 131; and when the pressure decreases or disappears, the exhaust valve bridge 1 moves upward under the action of the valve spring, the outlet 131 will be blocked by the blocking portion 52 again, and the exhaust valve bridge 1 will continue to move upward, which will drive the elastic valve stem 5 to move upward accordingly.

[0055] The working process of the internal combustion engine cylinder brake device of this embodiment is as follows:

[0056] Under normal operating conditions of the internal combustion engine:

[0057] The cam 3 drives the rocker arm 2, and through the valve adjustment bolt 4 and the mounting seat 41, drives the exhaust valve bridge 1 and the exhaust valve 11 to perform normal operations.

[0058] like Figure 3 As shown, when the second one-way valve 8 is open (the third one-way valve 9 is closed at this time), the lubricating oil of the internal combustion engine passes through the lubricating oil inlet 241 on the rocker shaft 24, the first through hole on the bushing 25, the lubricating oil channel 22, the second one-way valve 8 in sequence into the first oil channel 21, and then passes through the third oil channel 42 to enter the fourth oil channel 13 of the exhaust valve bridge 1. At this time, the rocker arm 2 makes a high-speed swinging motion, and the first valve ball 72 of the first one-way valve 7 allows oil to enter the fourth oil passage 13. Under the kinetic energy of the high-speed swinging of the rocker arm, the first valve ball 72 is in a slight opening and closing state (the first valve ball 72 slightly opens the inlet 132 of the fourth oil passage 13 under the action of its own gravity). At the same time, the movable seat 12 moves upward under the action of the fourth elastic member 120 and abuts against the lower end surface of the mounting seat 41. A small amount of lubricating oil will pass through the first one-way valve 7 to fill the gap space inside the movable seat 12, and because the movable seat 12 always maintains a tendency to abut against the lower end surface of the mounting seat 41 under the elastic action of the fourth elastic member 120. In this way, there is no gap between the mounting seat 41 and the movable seat 12, and the mounting seat 41 is connected to the valve adjustment bolt 4. If there is a gap between the cam 3 and the rocker arm 2, the rocker arm 2 will also swing slightly under the action of the force applied by the movable seat 12 to the mounting seat 41 to overcome the gap. In this way, when the internal combustion engine is operating normally, the noise of the entire transmission chain of the rocker arm 2 is reduced due to the extremely small valve clearance (almost zero clearance), the NVH performance is improved, and the service life of the entire transmission chain parts of the internal combustion engine rocker arm 2 is also increased, thereby greatly eliminating the valve clearance and the clearance between the cam 3 and the roller 26, and at the same time supplementing the clearance of the entire transmission chain after wear.

[0059] In addition, since the working pressure of the lubricating oil in the rocker arm 2 is extremely small at this time, when the valve is normally closed, the exhaust valve 11 will not be pushed away from the valve seat ring 111. At the same time, the friction surface between the exhaust valve bridge 1 and the exhaust valve 11 is also lubricated. Since the valve clearance is extremely small, the noise of the entire transmission chain of the rocker arm 2 is reduced.

[0060] The oil circuit of the internal combustion engine under normal operating conditions is as follows Figure 3 As shown by the dashed arrow in .

[0061] Under the operating conditions of the internal combustion engine exhaust brake:

[0062] like Figure 2 As shown, when the exhaust brake is working, the brake high-pressure oil of the internal combustion engine enters the first oil channel 21 through the high-pressure oil inlet 242 on the rocker shaft 24, the second through hole on the bushing 25, the high-pressure oil channel 23, and the third one-way valve 9 in sequence when the third one-way valve 9 is opened (at this time, the second one-way valve 8 is in a closed state under the action of the high-pressure oil). Then the brake high-pressure oil quickly opens the first one-way valve 7 through the third oil channel 42, and continuously and quickly injects high-pressure oil into the fourth oil channel 13 inside the movable seat 12. Under the pressure of the high-pressure oil, the movable seat 12 quickly moves upward and always abuts against the lower end surface of the mounting seat 41, and the exhaust valve The bridge 1 is forced to move downward quickly. When the exhaust valve bridge 1 moves downward and the bottom of the limit rod 51 on the elastic valve stem 5 hits the travel limit component 6, a slight relative movement occurs between the exhaust valve bridge 1 and the elastic valve stem 5, causing the outlet 131 of the fourth oil channel 13 to open a very small opening, and a small amount of brake high-pressure oil is released. At this time, the first valve ball 72 is basically in a closed state, but because the inlet 132 of the fourth oil channel 13 cannot be absolutely closed, the brake high-pressure oil will continue to enter the fourth oil channel 13 of the movable seat 12. The exhaust valve bridge 1 enters a balance in this state, allowing the exhaust brake of the internal combustion engine cylinder brake structure device to operate normally.

[0063] Under this operating condition, the lubricating oil of the internal combustion engine still operates according to the normal operating conditions of the internal combustion engine, but it cannot enter the first oil channel 21 through the second one-way valve 8. Therefore, when the brake high-pressure oil enters the first oil channel 21, there is no air in the entire oil channel, so there will be no phenomenon of high-pressure oil instantly impacting the exhaust valve bridge 1, and the timeliness, reliability and safety of exhaust braking are also improved.

[0064] The oil circuit under the condition of exhaust brake operation of the internal combustion engine is as follows Figure 2 As shown by the dashed arrow in .

[0065] When the exhaust brake of the internal combustion engine is released:

[0066] The lubricating oil of the internal combustion engine still operates according to the normal operating conditions of the internal combustion engine, but it cannot enter the first oil channel 21 through the second one-way valve 8. When the internal combustion engine cuts off the brake high-pressure oil from entering the exhaust valve bridge 1, the rocker arm 2 of the internal combustion engine is still swinging and operating normally. After the brake high-pressure oil is lost inside the movable seat 12, the brake high-pressure oil will leak out between the ball head structure of the valve adjustment bolt 4 and the ball socket of the mounting seat 41, between the bottom surface of the mounting seat 41 and the upper end surface of the movable seat 12, and between the movable seat 12 and the movable seat hole 14, causing the movable seat 12 to lose pressure quickly and sink. The exhaust valve bridge 1 rises rapidly under the action of the valve spring (not shown in the figure), and the elastic valve stem 5 leaves the travel limit component 6, so that the outlet 131 of the fourth oil channel 13 is closed. At the same time, the first valve ball 72 and the second valve ball 82 are opened, so that the lubricating oil can enter and return to the state as shown in the figure. Figure 3 The operating state of the internal combustion engine shown is normal operation.

Claims

1. An internal combustion engine cylinder brake device, comprising An exhaust valve bridge (1) on which an exhaust valve (11) is mounted; A rocker arm (2), one end of which is connected to a cam (3); A valve adjustment bolt (4), the upper end of which is connected to the other end of the rocker arm (2), and the lower end of which is connected to a mounting seat (41) located above the exhaust valve bridge (1) via a ball head structure; It is characterized in that Also includes A movable seat (12) is disposed in the exhaust valve bridge (1) and can move up and down relative to each other. The movable seat (12) maintains a tendency to abut against the lower end surface of the mounting seat (41) under the action of a fourth elastic member (120); An oil passage, which can switchably connect the lubricating oil inlet (241) or the high-pressure oil inlet (242) with the rocker arm (2), the valve adjustment bolt (4), the mounting seat (41), the movable seat (12) and finally the exhaust valve bridge (1) in sequence; An elastic valve stem (5) driven by a fourth elastic member (120) is disposed in the exhaust valve bridge (1) and extends downward through an outlet (131) of the oil passage; The stroke limiting component (6) is arranged on the cylinder head (61). When the cylinder brake is in effect, the movable seat (12) moves upward, the exhaust valve bridge (1) moves downward, the lower part of the elastic valve stem (5) contacts the stroke limiting component (6), so that a slight relative movement occurs between the exhaust valve bridge (1) and the elastic valve stem (5), and the elastic valve stem (5) opens the outlet (131) to leak high-pressure oil. The oil passage comprises a first oil passage (21) provided on the rocker arm (2), two second oil passages for respectively supplying lubricating oil and high-pressure oil to flow into the first oil passage (21), a third oil passage (42) sequentially penetrating the valve adjustment bolt (4) and the mounting seat (41), and a fourth oil passage (13) sequentially penetrating the movable seat (12) and the bottom of the exhaust valve bridge (1); when one of the second oil passages is in fluid communication with the first oil passage (21), the other second oil passage is disconnected from the first oil passage (21), and the third oil passage (42) is connected between the first oil passage (21) and the fourth oil passage (13); The elastic valve stem (5) comprises a limit rod (51) movably arranged in the outlet (131) of the fourth oil passage (13) and a shielding portion (52) radially formed on the upper end of the limit rod (51), the shielding portion (52) being located in the fourth oil passage (13) and capable of shielding the outlet (131), and the stroke limit component (6) being a column arranged below the exhaust valve bridge (1) and capable of abutting against the lower end of the limit rod (51); The movable seat (12) is provided with a first one-way valve (7) located in the fourth oil passage (13), the first one-way valve (7) comprising a U-shaped first valve seat (71), a first valve ball (72) arranged in the first valve seat (71), and a first elastic member (73) acting on the first valve ball (72), the first valve ball (72) being arranged adjacent to the inlet (132) of the fourth oil passage (13), and the first elastic member (73) enabling the first valve ball (72) to maintain a tendency to cover the inlet (132); The two second oil passages are respectively a lubricating oil passage (22) in fluid communication with the lubricating oil inlet (241) and a high-pressure oil passage (23) in fluid communication with the high-pressure oil inlet (242); a second one-way valve (8) is provided between the first oil passage (21) and the lubricating oil passage (22) for allowing only lubricating oil to flow from the lubricating oil passage (22) into the first oil passage (21); and a third one-way valve (9) is provided between the first oil passage (21) and the high-pressure oil passage (23) for allowing only brake high-pressure oil to flow from the high-pressure oil passage (23) into the first oil passage (21).

2. The internal combustion engine cylinder brake device according to claim 1, characterized in that: A limiting groove (121) is provided on the inner wall of the movable seat (12); a limiting flange (711) capable of abutting against the top wall and the bottom wall of the limiting groove (121) is formed on the outer wall of the first valve seat (71); the fourth elastic member (120) is a spring, one end of which abuts against the elastic valve stem (5) and the other end of which abuts against the limiting flange (711).

3. The internal combustion engine cylinder brake device according to claim 1, characterized in that: The second one-way valve (8) comprises a second valve body (81) arranged on the rocker arm (2); a second passage (811) connecting the lubricating oil passage (22) and the first oil passage (21) is opened on the second valve body (81); a second valve seat (80) is arranged in the second passage (811); a second valve ball (82) arranged in the second valve seat (80) and a second elastic member (83) acting on the second valve ball (82); the second elastic member (83) enables the second valve ball (82) to maintain a tendency to block the port of the second passage (811) close to the lubricating oil passage (22).

4. The internal combustion engine cylinder brake device according to claim 1, characterized in that: The third one-way valve (9) comprises a third valve body (91) arranged on the rocker arm (2); a third passage (911) connecting the high-pressure oil passage (23) and the first oil passage (21) is opened on the third valve body (91); a third valve ball (92) and a third elastic member (93) acting on the third valve ball (92) are arranged in the third passage (911); the third elastic member (93) enables the third valve ball (92) to maintain a tendency to block the port of the third passage (911) close to the high-pressure oil passage (23).

5. The internal combustion engine cylinder brake device according to claim 1, characterized in that: A bushing (25) is provided between the rocker arm (2) and the rocker arm shaft (24), and the bushing (25) is provided with a first through hole connecting the lubricating oil inlet (241) and the lubricating oil passage (22), and a second through hole connecting the high-pressure oil inlet (242) and the high-pressure oil passage (23).

6. The internal combustion engine cylinder brake device according to claim 1, characterized in that: The exhaust valve bridge (1) is provided with a movable seat hole (14), the movable seat (12) is movably arranged in the movable seat hole (14), and the movable seat hole (14) is connected to an oil passage located on the exhaust valve bridge (1).

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