Internal combustion engine in-cylinder brake combined rocker arm structure

Abstract

The invention discloses an internal combustion engine in-cylinder brake combined rocker arm structure which comprises a rocker arm shaft and a cam shaft, an air inlet rocker arm assembly, an exhaust rocker arm assembly, a brake rocker arm assembly and an electromagnetic valve assembly are assembled on the rocker arm shaft, and an air inlet cam, an exhaust cam and a brake cam are correspondingly arranged on the cam shaft. A brake is arranged on the brake rocker arm assembly, the end of the air inlet rocker arm assembly is matched with the air inlet valve assembly through an air inlet valve bridge, the end of the air outlet rocker arm assembly is matched with the air outlet valve assembly through an air outlet valve bridge, and the brake is matched with a brake pin arranged on the air outlet valve bridge. And a compensation type adjusting screw assembly is arranged on the exhaust rocker arm assembly. The exhaust valve bridge has the advantages that the structure is reasonable, the brake reliability and safety can be improved, the engine brake power is improved, the impact between the exhaust valve bridge and the end of the non-brake side valve rod is reduced, the engine noise is reduced, and the NVH is improved.

Description

Technical Field

[0001] The invention relates to the technical field of automobile internal combustion engine manufacturing, in particular to an internal combustion engine cylinder brake combined rocker arm structure. Background Art

[0002] With the continuous development of my country's road transportation, various medium and heavy-duty commercial vehicles have entered the transportation field of different industries, and safety during transportation is a top priority. The braking performance of various medium and heavy-duty commercial vehicles 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 brake to brake and slow down, which causes the brake to overheat, causing the brake efficiency to gradually decrease or even fail. The situation is more serious on rugged mountain roads with long slopes. Some medium and heavy-duty commercial vehicles will be equipped with a large water tank to water the brake hub for forced cooling. However, this will accelerate the serious consequences of wheel hub fatigue cracking, which directly poses a great threat to the safety of vehicle driving. In addition, in the cold winter, the water used to force cooling the brake hub will flow to the ground and freeze, which will cause major safety hazards to the driving of the following vehicles.

[0003] As the engine power of medium and heavy commercial vehicles is getting bigger and bigger, and the load is getting heavier, in some places with very harsh driving environment, the conventional braking power state of the engine can no longer meet the requirements of driving braking safety. Therefore, improving the engine braking performance, power and reliability is a very important research topic.

[0004] In order to improve the braking performance and power, an in-cylinder brake device was designed before. For details, see the patent application with application number CN202010823189.X. The in-cylinder brake device in the application includes a rocker arm shaft; an intake rocker arm structure, which is rotatably mounted on the rocker arm shaft; an exhaust rocker arm structure, including an exhaust valve bridge and an exhaust rocker arm assembly; a first brake rocker arm structure including a first brake rocker arm assembly, including a first brake cam and a first brake rocker arm rotatably mounted on the rocker arm shaft; a first brake control valve assembly, including a valve stem, which is connected to the other end of the first brake rocker arm and can move up and down relative to the first brake rocker arm, and can move downward to abut against the first exhaust valve under the action of high-pressure oil; a first elastic member, which keeps the valve stem moving upward and has a gap with the top of the first exhaust valve. In this way, the braking action of the first exhaust valve can be changed, the exhaust valve is opened in the compression stroke stage, and the high-pressure gas is discharged 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 improving the braking power.

[0005] Another in-cylinder brake device has been designed before, see the patent application with application number CN202010180539.5 for details. The in-cylinder brake device of this application includes 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, 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 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 even the exhaust valve bridge in sequence; an elastic valve stem driven by the fourth elastic member; a stroke limit component, which is arranged on the cylinder head; when the in-cylinder brake is effective, the movable seat moves upward, the exhaust valve bridge moves downward, the lower part of the elastic valve stem conflicts with the stroke limit component, and the elastic valve stem opens the outlet to leak high-pressure oil, thereby improving the accuracy and reliability of the exhaust brake.

[0006] However, in subsequent production and research, it was found that their structures still had room for improvement and their performance still had room for improvement, so the structure of the internal combustion engine cylinder brake rocker arm system was further improved. Summary of the invention

[0007] The purpose of the present invention is to make up for the above-mentioned deficiencies and disclose to the public a combined rocker arm structure for in-cylinder braking of an internal combustion engine, which has a reasonable structure and can improve braking reliability and safety, increase engine braking power, reduce the collision between the exhaust valve bridge and the non-braking side valve stem end, reduce engine noise, and improve NVH.

[0008] The technical solution of the present invention is achieved in this way: A combined rocker arm structure for in-cylinder braking of an internal combustion engine, comprising a rocker arm shaft and a camshaft, wherein the rocker arm shaft is equipped with an intake rocker arm assembly, an exhaust rocker arm assembly, a brake rocker arm assembly and a solenoid valve assembly, and the camshaft is correspondingly provided with an intake cam, an exhaust cam and a brake cam, wherein the brake is provided on the brake rocker arm assembly, the end of the intake rocker arm assembly is matched with the intake valve assembly via an intake valve bridge, the end of the exhaust rocker arm assembly is matched with the exhaust valve assembly via an exhaust valve bridge, and the brake is matched with a brake pin provided on the exhaust valve bridge; the exhaust rocker arm assembly is provided with an adjusting screw assembly, the adjusting screw assembly comprises an adjusting screw connected to the exhaust rocker arm assembly, the adjusting screw is connected with a locking nut, the lower end of the adjusting screw is connected with a rocker arm ball head, and the rocker arm ball head is connected with a sliding connector; A roller assembly is provided at the rear end of the brake rocker arm assembly, a spring seat is provided below the rear end of the brake rocker arm assembly, a pressure plate spring assembly consisting of a spring pressure plate and a spring is provided above the spring seat, the spring is provided between the spring pressure plate and the spring seat, and the roller assembly is always tangentially matched with the exhaust cam under the action of the pressure plate spring assembly.

[0009] The measures to further optimize this technical solution are: As an improvement, the adjustment screw assembly is replaced by a compensating adjustment screw assembly, which includes an adjustment screw connected to the exhaust rocker arm assembly, a locking nut connected to the adjustment screw, a rocker arm ball head connected to the lower end of the adjustment screw, a support spring arranged between the rocker arm ball head and the exhaust rocker arm assembly, a sliding connection connected to the rocker arm ball head, an inner cavity formed between the rocker arm ball head and the exhaust rocker arm assembly, and a mixing oil inlet hole and a mixing breathing hole communicating with the inner cavity are arranged on the exhaust rocker arm assembly.

[0010] As an improvement, the mixed oil inlet hole and the mixed breathing hole are arranged at the same generatrix position of the adjusting screw.

[0011] As an improvement, the mixed oil inlet hole is arranged on one generatrix of the adjusting screw, and the mixed breathing hole is arranged on another generatrix of the adjusting screw, and the angle between the two generatrixes is °.

[0012] As an improvement, a roller assembly is provided at the rear end of the exhaust rocker arm assembly, and a pressure plate spring assembly consisting of a spring pressure plate, a spring and a spring seat is provided above the roller assembly. Under the action of the pressure plate spring assembly, the roller assembly is always tangentially matched with the exhaust cam.

[0013] As an improvement, the brake includes a brake valve housing, a brake valve oil inlet hole is radially arranged on the brake valve housing, and an oil drain hole is arranged on the brake rocker arm assembly. A one-way valve assembly and a push rod matching the one-way valve assembly are assembled in the brake valve housing, and the push rod can be axially movably assembled in the upper part of the brake valve housing, and a push rod is assembled in the lower part of the brake valve housing, and the lower end of the push rod extends out of the brake valve housing, a return spring seat is arranged below the push rod, and a return spring is arranged between the return spring seat and the push rod.

[0014] As an improvement, the one-way valve assembly includes a one-way valve seat, a steel ball and a one-way valve spring. The one-way valve seat is fixed in the brake valve housing, the steel ball is abutted against the push rod, the one-way valve spring is arranged between the steel ball and the one-way valve seat, and the brake valve housing is provided with a conical surface that cooperates with the steel ball.

[0015] As an improvement, the specific structure in which the push rod can be axially movably assembled in the brake valve housing is as follows: a screw plug is fixed to the upper end of the brake valve housing, and a push rod spring is arranged between the screw plug and the push rod.

[0016] As an improvement, a brake pin cooperating with the brake tappet is provided on the exhaust valve bridge, an anti-slip portion is provided at the upper end of the brake pin, or an anti-slip portion is provided at the lower end of the position where the brake pin is installed on the exhaust valve bridge.

[0017] As an improvement, the intake valve assembly includes an intake valve, an intake valve spring and an intake valve seat ring. The intake valve passes through the intake valve seat ring and corresponds to the intake valve bridge. The intake valve spring sleeve is mounted on the outer periphery of the intake valve.

[0018] As an improvement, the exhaust valve assembly includes an exhaust valve, an exhaust valve spring and an exhaust valve seat ring. The exhaust valve passes through the exhaust valve seat ring and corresponds to the exhaust valve bridge. The exhaust valve spring sleeve is mounted on the outer periphery of the exhaust valve.

[0019] The advantages of the present invention compared with the prior art are: The combined rocker arm structure for in-cylinder braking of an internal combustion engine of the present invention has a reasonable structure. By arranging a brake on the braking rocker arm assembly, the braking power of the engine is improved. By arranging a compensating adjustment screw assembly on the exhaust rocker arm assembly, the collision between the exhaust valve bridge and the end of the valve stem on the non-brake side is reduced, the noise of engine operation is reduced, the NVH is improved, and the operating reliability and stability of the engine are further improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a three-dimensional structural diagram of the present invention; Figure 2 It is a schematic cross-sectional view of the in-cylinder brake structure of the internal combustion engine under ignition state of the present invention; Figure 3 yes Figure 2 Enlarged view of part A in the middle; Figure 4 It is a schematic cross-sectional structural diagram of the in-cylinder braking structure of the internal combustion engine in the in-cylinder braking state of the present invention; Figure 5 yes Figure 4 Enlarged view of middle part B; Figure 6 It is a schematic diagram of the structure of the brake of the present invention; Figure 7 It is one of the structural schematic diagrams of the compensating adjustment screw assembly of the present invention; Figure 8 This is the second structural schematic diagram of the compensating adjustment screw assembly of the present invention; Fig. 9It is one of the structural schematic diagrams of the exhaust valve bridge assembly of the present invention; Fig.10 This is the second schematic diagram of the exhaust valve bridge assembly structure of the present invention; Fig.11 This is the third schematic diagram of the exhaust valve bridge assembly structure of the present invention.

[0021] The names of the reference numerals in the accompanying drawings of the present invention are: Rocker arm shaft 1, rocker arm shaft lubricating oil passage 1a, rocker arm shaft brake oil passage 1b, intake rocker arm assembly 11, exhaust rocker arm assembly 12, mixed oil inlet hole 12a, mixed breathing hole 12b, brake rocker arm assembly 13, brake rocker arm brake oil passage 13a, oil drain hole 13b, camshaft 2, intake cam 21, exhaust cam 22, brake cam 23, brake 3, brake locking nut 3a, brake valve housing 31, brake valve oil inlet hole 31a, conical surface 31b, push rod 32, push rod 33, return spring seat 33a, return spring 33b, one-way valve seat 3 4, steel ball 35, one-way valve spring 36, plug screw 37, push rod spring 38, retaining ring 39, intake valve bridge 4, intake valve assembly 5, intake valve 51, intake valve spring 52, intake valve seat ring 53, exhaust valve bridge 6, brake pin 61, anti-slip portion 61a, exhaust valve assembly 7, exhaust valve 71, exhaust valve spring 72, exhaust valve seat ring 73, inner cavity 8a, adjustment screw 81, locking nut 82, rocker arm ball head 83, support spring 84, sliding connector 85, solenoid valve assembly 9, roller assembly 91, spring pressure plate 92, spring 93, spring seat 94. DETAILED DESCRIPTION

[0022] The present invention is further described in detail below in conjunction with the accompanying drawings: The following description is used to disclose the present invention so that those skilled in the art can implement the present invention. The preferred embodiments described below are only examples, and those skilled in the art can think of other obvious variations. The basic principles of the present invention defined in the following description can be used for other embodiments, variations, improvements, equivalents, and other technical solutions that do not deviate from the spirit and scope of the present invention.

[0023] Those skilled in the art should understand that, in the disclosure of the present invention, the directions or positions indicated by the terms "longitudinal", "lateral", "up", "down", "left", "right", "front", "back", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc. are based on the directions or positional relationships shown in the accompanying drawings, which are only simplified descriptions for the convenience of describing the present invention, and do not indicate or imply that the device or component referred to must have a specific direction, be constructed and operated in a specific direction. Therefore, the above terms should not be understood as limitations on the present invention.

[0024] It is to be understood that the term "one" should be understood as "at least one" or "one or more", that is, in one embodiment, the number of an element may be one, while in another embodiment, the number of the element may be multiple, and the term "one" should not be understood as a limitation on the quantity.

[0025] like Figures 1 to 11 As shown, a combined rocker arm structure for in-cylinder braking of an internal combustion engine includes a rocker arm shaft 1 and a camshaft 2. The rocker arm shaft 1 is equipped with an intake rocker arm assembly 11, an exhaust rocker arm assembly 12, a brake rocker arm assembly 13 and a solenoid valve assembly 9. The camshaft 2 is correspondingly provided with an intake cam 21, an exhaust cam 22 and a brake cam 23. The brake rocker arm assembly 13 is characterized in that a brake 3 is provided on the brake rocker arm assembly 13, the end of the intake rocker arm assembly 11 cooperates with the intake valve assembly 5 via the intake valve bridge 4, and the The end of the exhaust rocker arm assembly 12 cooperates with the exhaust valve assembly 7 via the exhaust valve bridge 6, and the brake 3 cooperates with the brake pin 61 arranged on the exhaust valve bridge 6; the exhaust rocker arm assembly 12 is provided with an adjusting screw assembly, and the adjusting screw assembly includes an adjusting screw 81 connected to the exhaust rocker arm assembly 12, and the adjusting screw 81 is connected to a locking nut 82, and the lower end of the adjusting screw 81 is connected to a rocker arm ball head 83, and the rocker arm ball head 83 is connected to a sliding connection 85; A roller assembly 91 is provided at the rear end of the brake rocker arm assembly 13, and a spring seat 94 is provided below the rear end of the brake rocker arm assembly 13. A pressure plate spring assembly consisting of a spring pressure plate 92 and a spring 93 is provided above the spring seat 94. The spring 93 is provided between the spring pressure plate 92 and the spring seat 94. Under the action of the pressure plate spring assembly, the roller assembly 91 is always tangentially matched with the exhaust cam 22.

[0026] The rocker shaft 1 is provided with a rocker shaft lubricating oil passage 1a and a rocker shaft braking oil passage 1b.

[0027] As a further improvement, the adjusting screw assembly is replaced by a compensating adjusting screw assembly, which includes an adjusting screw 81 connected to the exhaust rocker arm assembly 12, a locking nut 82 being connected to the adjusting screw 81, a rocker arm ball head 83 being connected to the lower end thereof, a supporting spring 84 being arranged between the rocker arm ball head 83 and the exhaust rocker arm assembly 12, a sliding connection 85 being connected to the rocker arm ball head 83, an inner cavity 8a being formed between the rocker arm ball head 83 and the exhaust rocker arm assembly 12, and a mixing oil inlet hole 12a and a mixing breathing hole 12b being arranged on the exhaust rocker arm assembly 12 and communicating with the inner cavity 8a.

[0028] In this embodiment, the compensating adjustment screw assembly is designed with two structures, such as Figure 7As shown in FIG. 1 , one of the structures is that the mixed oil inlet hole 12a and the mixed breathing hole 12b are arranged at the same generatrix position of the adjustment screw 81, that is, the mixed oil inlet hole 12a and the mixed breathing hole 12b are arranged on the same side. Figure 8 As shown, another structure is shown, the mixed oil inlet hole 12a is arranged on a busbar of the adjusting screw 81, and the mixed breathing hole 12b is arranged on another busbar of the adjusting screw 81, and the angle between the two busbars is 180°, that is, the mixed oil inlet hole 12a is arranged on the opposite side of the mixed breathing hole 12b.

[0029] like Figure 6 As shown, the brake 3 includes a brake valve housing 31, a brake valve oil inlet hole 31a is radially arranged on the brake valve housing 31, and an oil drain hole 13b is arranged on the brake rocker arm assembly 13. A check valve assembly and a push rod 32 matched with the check valve assembly are assembled in the brake valve housing 31, and the push rod 32 can be axially movably assembled in the upper part of the brake valve housing 31. A push rod 33 is assembled in the lower part of the brake valve housing 31, and the lower end of the push rod 33 extends out of the brake valve housing 31. A return spring seat 33a is arranged below the push rod 33, and a return spring 33b is arranged between the return spring seat 33a and the push rod 33. A brake locking nut 3a is arranged at the upper end of the brake valve housing 31.

[0030] The one-way valve assembly includes a one-way valve seat 34, a steel ball 35 and a one-way valve spring 36. The one-way valve seat 34 is fixed in the brake valve housing 31. The steel ball 35 is matched with the push rod 32. The one-way valve spring 36 is arranged between the steel ball 35 and the one-way valve seat 34. The brake valve housing 31 is provided with a conical surface 31b matched with the steel ball 35. After the one-way valve seat 34 is assembled, a hole wire retaining ring is used for limiting and fixing.

[0031] The specific structure of the push rod 32 being axially movable and assembled in the brake valve housing 31 is as follows: a screw plug 37 is fixed to the upper end of the brake valve housing 31, and a push rod spring 38 is arranged between the screw plug 37 and the push rod 32. Similarly, the outer side of the screw plug 37 is limited by a hole wire retaining ring. A retaining ring 39 is arranged at the lower end of the brake valve housing 31.

[0032] The exhaust valve bridge 6 is provided with a brake pin 61 that matches the tappet 33 of the brake 3, and the upper end of the brake pin 61 is provided with an anti-slip portion 61a, or the lower end of the position where the brake pin 61 is installed on the exhaust valve bridge 6 is provided with an anti-slip portion 61a. In this embodiment, the exhaust valve bridge 6 is designed with three structures, one of which is as follows: Fig. 9As shown, the exhaust valve bridge 6 is provided with a brake pin 61 that matches the tappet 33 of the brake 3, and the upper end of the brake pin 61 is provided with an anti-slip portion 61a, and the surface of the non-brake side of the valve bridge that abuts against the exhaust valve can be a plane, a spherical surface, or a cylindrical surface. Fig.10 As shown, a brake pin 61 is provided on the exhaust valve bridge 6 to match the tappet 33 of the brake 3. The upper part of the brake pin 61 is a cylindrical structure. The lower end of the exhaust valve bridge 6 where the brake pin 61 is installed is provided with an anti-slip portion 61a. The surface of the exhaust valve bridge 6 that abuts against the exhaust valve on the non-braking side can be a plane, a spherical surface, or a cylindrical surface. In this structure, the surface of the valve bridge that abuts against the exhaust valve on the non-braking side is a plane. Third, as Fig.11 As shown, similarly, a brake pin 61 cooperating with the push rod 33 of the brake 3 is provided on the exhaust valve bridge 6, and an anti-slip portion 61a is provided at the lower end of the exhaust valve bridge 6 where the brake pin 61 is installed. In this structure, the surface of the non-braking side of the exhaust valve bridge 6 that abuts against the exhaust valve is a cylindrical surface.

[0033] The intake valve assembly 5 includes an intake valve 51 , an intake valve spring 52 and an intake valve seat ring 53 . The intake valve 51 passes through the intake valve seat ring 53 and corresponds to the intake valve bridge 4 . The intake valve spring 52 is sleeved on the outer periphery of the intake valve 51 .

[0034] The exhaust valve assembly 7 includes an exhaust valve 71 , an exhaust valve spring 72 and an exhaust valve seat ring 73 . The exhaust valve 71 passes through the exhaust valve seat ring 73 and corresponds to the exhaust valve bridge 6 . The exhaust valve spring 72 is sleeved on the outer periphery of the exhaust valve 71 .

[0035] Working principle: (1) Brake clearance adjustment: When the exhaust valve is closed, adjust the brake clearance. The specific adjustment process is as follows: First, loosen the brake lock nut 3a so that the plug 37 can be turned up and down. Since a hole wire retaining ring is installed on the upper end of the plug 37, the plug 37 will not loosen when it is turned up and down, and can directly drive the brake valve housing 31 to rotate, so that the brake valve housing 31 can move up and down. The push rod 33 moves up and down synchronously close to the brake valve housing 31 under the action of the return spring 33b. The return spring 33b has a support point on the return spring seat 33a to ensure the stability of the return spring 33b. The return spring seat 33a is fixed to the brake rocker assembly 13 with a hole wire retaining ring. At this time, put the feeler gauge for setting the brake clearance between the brake pin 61 of the exhaust valve bridge 6 and the push rod 33 of the brake 3. Screw the plug 37 downward until it is screwed to the thickness of the feeler gauge for setting the brake clearance, and then tighten the brake lock nut 3a.

[0036] (2) Exhaust valve clearance adjustment: When the exhaust valve is closed, adjust the compensating adjustment screw assembly on the exhaust rocker arm assembly 12: First, loosen the locking nut 82, screw the adjusting screw 81 upward, and drive the rocker ball head 83 to move upward, thereby driving the sliding connection 85 to move upward. As the rocker ball head 83 moves upward, the support spring 84 is compressed, so that the exhaust valve setting clearance feeler gauge can be placed between the exhaust valve bridge 6 and the sliding connection 85. Then screw the adjusting screw 81 downward, so that the rocker ball head 83 and the sliding connection 85 move downward together, and the lower end plane of the adjusting screw 81 abuts against the rocker ball head 83, so that the rocker ball head 83 and the sliding connection 85 move downward together, until it is screwed to the thickness of the exhaust valve setting clearance feeler gauge, and then lock the locking nut 82.

[0037] In the present invention, the main function of the compensating adjustment screw assembly is that under the working condition of exhaust brake operation in the cylinder of the internal combustion engine, the rocker arm ball head 83, under the action of the support spring 84, can quickly compensate for the gap between the exhaust valve bridge 6 and the sliding connection 85 during braking, prevent the exhaust valve bridge from jumping out due to excessive valve clearance during braking, reduce the impact force on the exhaust valve bridge 6 during braking, and ensure lubrication between the exhaust valve bridge 6 and the sliding connection 85. During the rapid movement of the rocker arm ball head 83, lubricating oil enters from the mixed oil inlet hole 12a, and the gas generated when the rocker arm ball head 83 moves upward is discharged from the mixed breathing hole 12b.

[0038] (3) Exhaust valve bridge assembly: The exhaust valve bridge 6 is a key component for reliable realization of the braking function in the engine cylinder.

[0039] A brake pin 61 is provided at one end of the exhaust valve bridge 6. The end provided with the brake pin 61 is the brake end, and the other end is the non-brake end. The bottom surface of the non-brake end can be a plane, a spherical surface, a cylindrical surface, a round hole or a waist-shaped hole, which can be selected and set according to different brake structures. By setting the anti-slip portion 61a, the brake pin 61 and the exhaust valve bridge 6 can be reliably assembled together, ensuring the safety and reliability of the engine operation.

[0040] (4) Under normal operating conditions of the internal combustion engine: Intake rocker arm assembly 11: During normal operation, the intake rocker arm assembly 11 operates according to the profile track of the intake cam 21 under the action of the intake cam 21, and through the intake valve bridge 4, the intake valve assembly 5 operates in a normal state.

[0041] Exhaust rocker arm assembly 12: During normal operation, the exhaust rocker arm assembly 12 operates according to the profile track of the exhaust cam 22 under the action of the exhaust cam 22, and through the exhaust valve bridge 6, the exhaust valve assembly 7 operates in a normal state.

[0042] Brake rocker arm assembly 13: Under the action of the pressure plate spring assembly, the roller assembly of the brake rocker arm assembly 13 and the brake cam 23 are always tangent during operation, so that the brake rocker arm assembly 13 runs along the track of the brake cam 23.

[0043] In this state, since the brake control oil does not enter the brake rocker arm brake oil channel 13a, the tappet 33 does not collide with the brake pin 61, and the normal operation of the exhaust rocker arm assembly 12 and the exhaust valve assembly 7 is not affected.

[0044] (4) When the internal combustion engine exhaust brake is in operation: Intake rocker arm assembly 11: During normal operation, the intake rocker arm assembly 11 operates according to the profile track of the intake cam 21 under the action of the intake cam 21, and through the intake valve bridge 4, the intake valve assembly 5 operates in a normal state.

[0045] Exhaust rocker arm assembly 12: During normal operation, the exhaust rocker arm assembly 12 operates according to the profile track of the exhaust cam 22 under the action of the exhaust cam 22, and through the exhaust valve bridge 6, the exhaust valve assembly 7 operates in a normal state.

[0046] Brake rocker arm assembly 13: When the internal combustion engine needs to perform in-cylinder exhaust braking, the solenoid valve assembly 9 is started, so that the brake high-pressure oil passes through the rocker shaft brake oil channel 1b in the rocker shaft 1, and enters the brake 3 through the brake rocker brake oil channel 13a, so that the push rod 32 overcomes the elastic force of the push rod spring 38 and moves upward, and at the same time opens the steel ball 35 engaged with the conical surface 31b, compresses the one-way valve spring 36 on the one-way valve seat 34, so that the high-pressure oil quickly enters the oil chamber of the brake 3, so that the push rod 33 overcomes the elastic force of the return spring 33b, and quickly moves downward to the retaining ring 39, and the push rod 33 is against the brake pin 61 on the exhaust valve bridge 6, forcing the brake pin 61 to move downward, so that the exhaust brake side valve operates according to the cam profile trajectory of the brake cam 23, and continues to establish this working state, and enters the in-cylinder braking operation. At this time, under the action of the pressure plate spring assembly, the roller assembly of the brake rocker arm assembly 13 and the brake cam 23 are always tangent during operation, so that the brake rocker arm assembly 13 runs along the trajectory of the brake cam 23.

[0047] (6) When the exhaust brake of the internal combustion engine is released: Intake rocker arm assembly 11: During normal operation, the intake rocker arm assembly 11 operates according to the profile track of the intake cam 21 under the action of the intake cam 21, and through the intake valve bridge 4, the intake valve assembly 5 operates in a normal state.

[0048] Exhaust rocker arm assembly 12: During normal operation, the exhaust rocker arm assembly 12 operates according to the profile track of the exhaust cam 22 under the action of the exhaust cam 22, and through the exhaust valve bridge 6, the exhaust valve assembly 7 operates in a normal state.

[0049] Brake rocker arm assembly 13: When the internal combustion engine needs to cancel the in-cylinder exhaust brake, the solenoid valve assembly 9 is closed. At this time, the push rod 32 of the brake 3 moves downward rapidly under the action of the push rod spring 38, overcomes the elastic force of the one-way valve spring 36, and quickly pushes open the steel ball 35 in the brake 3. At the same time, the push rod 33 in the brake 3, under the action of the return spring 33b, moves upward rapidly and abuts against the bottom of the brake valve housing 31. The high-pressure oil is quickly discharged from the brake rocker arm brake oil channel 13a through the oil channel. The original ignition working state of the internal combustion engine is restored.

[0050] At this time, the exhaust valve 71 on the brake side moves upward quickly under the action of the exhaust valve spring 72, restoring the original working state of the brake pin 61 and maintaining the original gap with the lower end surface of the tappet 33. At this time, under the action of the pressure plate spring assembly, the roller assembly of the brake rocker arm assembly 13 and the brake cam 23 are always tangent during the operation, so that the brake rocker arm assembly 13 runs along the track of the brake cam 23. In this state, the exhaust brake operation of the internal combustion engine is released.

[0051] The combined rocker arm structure for in-cylinder braking of an internal combustion engine of the present invention has a reasonable structure. By arranging a brake on the braking rocker arm assembly, the braking power of the engine is improved. By arranging a compensating adjustment screw assembly on the exhaust rocker arm assembly, the collision between the exhaust valve bridge and the end of the valve stem on the non-brake side is reduced, the noise of engine operation is reduced, the NVH is improved, and the operating reliability and stability of the engine are further improved.

[0052] The above are only preferred embodiments of the present invention, and are not intended to limit the implementation methods and protection scope of the present invention. Those skilled in the art should be aware that all solutions obtained by equivalent substitutions and obvious changes made using the description and illustrations of the present invention should be included in the protection scope of the present invention.

Claims

1. An internal combustion engine cylinder brake combined rocker arm structure, comprising a rocker arm shaft (1) and a camshaft (2), wherein the rocker arm shaft (1) is equipped with an intake rocker arm assembly (11), an exhaust rocker arm assembly (12), a brake rocker arm assembly (13) and a solenoid valve assembly (9), and the camshaft (2) is correspondingly provided with an intake cam (21), an exhaust cam (22) and a brake cam (23), wherein: The brake rocker arm assembly (13) is provided with a brake (3), the end of the intake rocker arm assembly (11) cooperates with the intake valve assembly (5) via the intake valve bridge (4), the end of the exhaust rocker arm assembly (12) cooperates with the exhaust valve assembly (7) via the exhaust valve bridge (6), and the brake (3) cooperates with a brake pin (61) provided on the exhaust valve bridge (6); the exhaust rocker arm assembly (12) is provided with an adjustment screw assembly, the adjustment screw assembly includes an adjustment screw (81) connected to the exhaust rocker arm assembly (12), the adjustment screw (81) is connected to a locking nut (82), the lower end of the adjustment screw (81) is connected to a rocker arm ball head (83), and the rocker arm ball head (83) is connected to a sliding connection (85); A roller assembly (91) is arranged at the rear end of the brake rocker arm assembly (13); a spring seat (94) is arranged below the rear end of the brake rocker arm assembly (13); a pressure plate spring assembly consisting of a spring pressure plate (92) and a spring (93) is arranged above the spring seat (94); the spring (93) is arranged between the spring pressure plate (92) and the spring seat (94); and the roller assembly (91) is always tangentially matched with the exhaust cam (22) under the action of the pressure plate spring assembly.

2. The internal combustion engine cylinder brake combined rocker arm structure according to claim 1, characterized in that: The adjusting screw assembly is replaced by a compensating adjusting screw assembly, which includes an adjusting screw (81) connected to the exhaust rocker arm assembly (12), the adjusting screw (81) is connected to a locking nut (82), the lower end of the adjusting screw (81) is connected to a rocker arm ball head (83), a supporting spring (84) is provided between the rocker arm ball head (83) and the exhaust rocker arm assembly (12), a sliding connection (85) is connected to the rocker arm ball head (83), an inner cavity (8a) is formed between the rocker arm ball head (83) and the exhaust rocker arm assembly (12), and the exhaust rocker arm assembly (12) is provided with a mixing oil inlet hole (12a) and a mixing breathing hole (12b) which are communicated with the inner cavity (8a).

3. The internal combustion engine cylinder brake combined rocker arm structure according to claim 2, characterized in that: The mixed oil inlet hole (12a) and the mixed breathing hole (12b) are arranged at the same generatrix position of the adjustment screw (81).

4. The internal combustion engine cylinder brake combined rocker arm structure according to claim 2, characterized in that: The mixing oil inlet hole (12a) is arranged on one generatrix of the adjusting screw (61), and the mixing breathing hole (12b) is arranged on another generatrix of the adjusting screw (61), and the angle between the two generatrixes is 180°.

5. The combined rocker arm structure for in-cylinder braking of an internal combustion engine according to claim 3 or 4, characterized in that: The brake (3) comprises a brake valve housing (31), a brake valve oil inlet hole (31a) is radially arranged on the brake valve housing (31), an oil drain hole (13b) is arranged on the brake rocker arm assembly (13), a one-way valve assembly and a push rod (32) matched with the one-way valve assembly are assembled in the brake valve housing (31), the push rod (32) can be axially movably assembled in the upper part of the brake valve housing (31), a push rod (33) is assembled in the lower part of the brake valve housing (31), the lower end of the push rod (33) extends out of the brake valve housing (31), a return spring seat (33a) is arranged below the push rod (33), and a return spring (33b) is arranged between the return spring seat (33a) and the push rod (33).

6. The internal combustion engine cylinder brake combined rocker arm structure according to claim 5, characterized in that: The one-way valve assembly comprises a one-way valve seat (34), a steel ball (35) and a one-way valve spring (36); the one-way valve seat (34) is fixed in a brake valve housing (31); the steel ball (35) is abutted against a push rod (32); the one-way valve spring (36) is arranged between the steel ball (35) and the one-way valve seat (34); and a conical surface (31b) matching with the steel ball (35) is arranged on the brake valve housing (31).

7. The internal combustion engine cylinder brake combined rocker arm structure according to claim 6, characterized in that: The specific structure of the push rod (32) being axially movable and assembled in the brake valve housing (31) is as follows: a screw plug (37) is fixed to the upper end of the brake valve housing (31), and a push rod spring (38) is arranged between the screw plug (37) and the push rod (32).

8. The combined rocker arm structure for in-cylinder braking of an internal combustion engine according to claim 7, characterized in that: The exhaust valve bridge (6) is provided with a brake pin (61) matched with the tappet (33) of the brake (3), and the upper end of the brake pin (61) is provided with an anti-slip portion (61a), or the lower end of the position where the brake pin (61) is installed on the exhaust valve bridge (6) is provided with an anti-slip portion (61a).

9. The internal combustion engine cylinder brake combined rocker arm structure according to claim 8, characterized in that: The intake valve assembly (5) comprises an intake valve (51), an intake valve spring (52) and an intake valve seat ring (53); the intake valve (51) passes through the intake valve seat ring (53) and corresponds to the intake valve bridge (4); the intake valve spring (52) is sleeved on the outer periphery of the intake valve (51).

10. The combined rocker arm structure for in-cylinder braking of an internal combustion engine according to claim 8, characterized in that: The exhaust valve assembly (7) comprises an exhaust valve (71), an exhaust valve spring (72) and an exhaust valve seat ring (73); the exhaust valve (71) passes through the exhaust valve seat ring (73) and corresponds to the exhaust valve bridge (6); the exhaust valve spring (72) is sleeved on the outer periphery of the exhaust valve (71).

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