A combined rocker arm system for in-cylinder braking of an internal combustion engine

Abstract

The present invention discloses a combined rocker arm system 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, wherein the camshaft is correspondingly provided with an intake cam, an exhaust cam and a brake cam, wherein the brake rocker arm assembly is provided with a brake, and the brake cooperates with a brake pin provided on an exhaust valve bridge; wherein the exhaust rocker arm assembly comprises a front exhaust rocker arm and a rear exhaust rocker arm, wherein a hydraulic tappet assembly is provided between the front exhaust rocker arm and the rear exhaust rocker arm, and wherein a control valve assembly is provided on the exhaust rocker arm assembly. The advantages of the present invention are: the internal combustion engine can achieve the purpose of high-power braking, the structure is reasonable, the braking reliability and safety can be improved, the engine noise can be reduced, and the NVH can be 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 system. 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 system for in-cylinder braking of an internal combustion engine, so that the internal combustion engine can achieve the purpose of high-power braking. Its structure is reasonable, and it can improve braking reliability and safety, increase engine braking power, reduce engine noise, and improve NVH.

[0008] The technical solution of the present invention is achieved in this way:

[0009] An internal combustion engine cylinder brake combined rocker arm system, comprising a rocker arm shaft and a camshaft, 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, the camshaft is correspondingly provided with an intake cam, an exhaust cam and a brake cam, the brake rocker arm assembly is provided with a brake, 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;

[0010] The exhaust rocker arm assembly includes a front exhaust rocker arm and a rear exhaust rocker arm, a hydraulic tappet assembly is arranged between the front exhaust rocker arm and the rear exhaust rocker arm, the hydraulic tappet assembly includes a tappet housing, a tappet, a connecting ball head and a sliding connection piece, the tappet housing is fixed to the front exhaust rocker arm, the sliding connection piece is abutted against the rear exhaust rocker arm, one end of the connecting ball head is assembled on the tappet, and the other end is matched with the sliding connection piece, the tappet is provided with a tappet oil passage, a one-way valve steel ball is assembled on the tappet oil passage, and a tappet support spring is arranged between the tappet and the tappet housing;

[0011] The exhaust rocker arm assembly is also provided with a control valve assembly, the control valve assembly includes a control valve core, and a control valve return spring is provided between the control valve core and the exhaust rocker arm assembly.

[0012] The measures to further optimize this technical solution are:

[0013] As an improvement, a roller assembly is provided at the rear end of the rear exhaust rocker arm, 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 in tangential cooperation with the exhaust cam.

[0014] 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.

[0015] 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.

[0016] 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.

[0017] As an improvement, 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.

[0018] As an improvement, a brake pin cooperating with the tappet of the brake is provided on the exhaust valve bridge.

[0019] As an improvement, the upper end of the brake pin is provided with an anti-slip portion, or the lower end of the position where the brake pin is installed on the exhaust valve bridge is provided with an anti-slip portion.

[0020] 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.

[0021] 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.

[0022] The advantages of the present invention compared with the prior art are:

[0023] The invention discloses an internal combustion engine cylinder brake combined rocker arm system, which has a reasonable structure and includes an intake rocker arm assembly, an exhaust rocker arm assembly, and a brake rocker arm assembly, wherein the exhaust rocker arm assembly includes a front exhaust rocker arm, a rear exhaust rocker arm, and a hydraulic tappet assembly, and a control valve assembly is arranged in the exhaust rocker arm assembly, so that the structure is more reasonable and compact. At the same time, the exhaust rocker arm assembly has a clearance compensation function through the arrangement of the hydraulic tappet assembly, so that the engine manufacturing company does not need to adjust the valve clearance when assembling the exhaust rocker arm assembly, and the user does not need to adjust the exhaust valve clearance in the future, which reduces the operating cost, improves the operating efficiency of the engine, and solves the potential risk of exhaust valve bridge jumping caused by poor exhaust valve follow-up due to cylinder braking, which can reduce the noise of engine operation and improve NVH. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a three-dimensional structural diagram of the present invention;

[0025] Figure 2 It is a schematic cross-sectional view of the brake structure of the internal combustion engine of the present invention when it is in an ignition state;

[0026] Figure 3 yes Figure 2 Enlarged view of part A in the middle;

[0027] Figure 4 It is a schematic cross-sectional view of the brake structure of the internal combustion engine cylinder in a braking state according to the present invention;

[0028] Figure 5 yes Figure 4 Enlarged view of middle part B;

[0029] Figure 6 is a schematic cross-sectional view of the exhaust rocker arm assembly of the present invention;

[0030] Figure 7 yes Figure 6 Enlarged view of middle C;

[0031] Figure 8 It is a schematic cross-sectional view of the exhaust rocker arm assembly of the internal combustion engine of the present invention under ignition state;

[0032] Fig. 9 yes Figure 8 Enlarged view of the middle D part;

[0033] Fig.10 It is a schematic cross-sectional view of the exhaust rocker arm assembly of the internal combustion engine in a braking state of the present invention;

[0034] Fig.11 yes Fig.10 Enlarged view of middle E part;

[0035] Fig.12 It is a structural schematic diagram of the brake of the present invention;

[0036] Fig.13 It is one of the structural schematic diagrams of the exhaust valve bridge assembly of the present invention;

[0037] Fig.14 This is the second schematic diagram of the exhaust valve bridge assembly structure of the present invention;

[0038] Fig.15 This is the third schematic diagram of the exhaust valve bridge assembly structure of the present invention.

[0039] The names of the reference numerals in the accompanying drawings of the present invention are:

[0040] 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, front exhaust rocker arm 12a, rear exhaust rocker arm 12b, tappet housing 12c, tappet 12d, connecting ball head 12e, sliding connection 12f, tappet oil passage 12h, one-way valve steel ball 12i, tappet support spring 12j, control valve spool 12k, control valve return spring 12l, hydraulic tappet low-pressure oil chamber 12m, hydraulic tappet high-pressure oil chamber 12n, control valve high-pressure oil chamber 12o, 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 34, steel ball 35, one-way valve spring 36, screw plug 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, solenoid valve assembly 8, roller assembly 91, spring pressure plate 92, spring 93, spring seat 94. DETAILED DESCRIPTION

[0041] The present invention is further described in detail below in conjunction with the accompanying drawings:

[0042] 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.

[0043] 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.

[0044] 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.

[0045] like Figures 1 to 15 As shown, a combined rocker arm system 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 8. 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 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, and the end of the exhaust rocker arm assembly 12 cooperates with the exhaust valve assembly 7 via the exhaust valve bridge 6. The brake 3 cooperates with a brake pin 61 provided on the exhaust valve bridge 6.

[0046] The exhaust rocker arm assembly 12 includes a front exhaust rocker arm 12a and a rear exhaust rocker arm 12b, a hydraulic tappet assembly is arranged between the front exhaust rocker arm 12a and the rear exhaust rocker arm 12b, the hydraulic tappet assembly includes a tappet housing 12c, a tappet 12d, a connecting ball head 12e and a sliding connection 12f, the tappet housing 12c is fixed to the front exhaust rocker arm 12a, the sliding connection 12f is abutted against the rear exhaust rocker arm 12b, one end of the connecting ball head 12e is assembled on the tappet 12d, and the other end is matched with the sliding connection 12f, a tappet oil passage 12h is arranged on the tappet 12d, a one-way valve steel ball 12i is assembled on the tappet oil passage 12h, and a tappet support spring 12j is arranged between the tappet 12d and the tappet housing 12c. In the hydraulic tappet assembly, a hydraulic tappet low-pressure oil chamber 12m and a hydraulic tappet high-pressure oil chamber 12n are respectively formed on both sides of the one-way valve steel ball 12i.

[0047] A control valve assembly is also provided on the exhaust rocker arm assembly 12, and the control valve assembly includes a control valve core 12k. A control valve return spring 12l is provided between one end of the control valve core 12k and the exhaust rocker arm assembly 12, and a control valve high-pressure oil chamber 12o is formed between the other end face of the control valve core 12k and the exhaust rocker arm assembly 12.

[0048] The rocker shaft 1 is provided with a rocker shaft lubricating oil passage 1a and a rocker shaft braking oil passage 1b, and the brake rocker arm assembly 13 is provided with a brake rocker arm braking oil passage 13a.

[0049] A roller assembly 91 is provided at the rear end of the rear exhaust rocker arm 12b, and a pressure plate spring assembly consisting of a spring pressure plate 92, a spring 93 and a spring seat 94 is provided above the roller assembly 91. Under the action of the pressure plate spring assembly, the roller assembly 91 is always tangentially matched with the exhaust cam 22.

[0050] like Fig.12As shown, the brake 3 includes a brake valve housing 31, on which a brake valve oil inlet hole 31a is radially arranged, and 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, and the push rod 32 can be axially movably assembled in the upper part of the brake valve housing 31, and 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 brake locking nut 3a is arranged at the upper end of the brake valve housing 31.

[0051] 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.

[0052] 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.

[0053] A return spring seat 33 a is disposed below the push rod 33 , and a return spring 33 b is disposed between the return spring seat 33 a and the push rod 33 .

[0054] In this embodiment, the exhaust valve bridge 6 is designed with three structures, one of which is as follows: Fig.13 As 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.14 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.15As 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.

[0055] 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 .

[0056] 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 .

[0057] Working principle:

[0058] (1) Brake clearance adjustment:

[0059] When the exhaust valve is closed, adjust the brake clearance. The specific adjustment process is as follows:

[0060] 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.

[0061] (2) Exhaust valve bridge assembly:

[0062] The exhaust valve bridge 6 is a key component for reliable realization of the braking function in the engine cylinder.

[0063] 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.

[0064] (3) Under normal operating conditions of the internal combustion engine:

[0065] Intake rocker arm assembly 11:

[0066] 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.

[0067] Exhaust rocker arm assembly 12:

[0068] During normal operation, the lubricating oil quickly enters the rocker shaft lubricating oil passage 1a, enters the hydraulic tappet low-pressure oil chamber 12m through the oil inlet passage, and enters the tappet oil passage 12h to open the one-way valve steel ball 12i, allowing the lubricating oil to enter the hydraulic tappet high-pressure oil chamber 12n. Under the joint action of the tappet support spring 12j and the high-pressure oil in the hydraulic tappet high-pressure oil chamber 12n, the tappet 12d, the connecting ball head 12e, and the sliding connector 12f quickly move to the rear exhaust rocker arm 12b, and at the same time, the rear exhaust rocker arm 12b cooperates with the rotation of the pin shaft to quickly push and rotate the front exhaust rocker arm 12a. On the rear exhaust rocker arm 12b, under the action of the spring pressure plate 92, the spring 93, and the spring seat 94, the roller assembly 91 and the exhaust cam 22 are always tangent during the movement, so that the sliding member at the front end of the exhaust rocker arm assembly 12 is tangent to the exhaust valve bridge 6, and the gap between the sliding member and the exhaust valve bridge 6 is quickly eliminated to form a rigid body, so that the exhaust rocker arm assembly 12 and the exhaust valve bridge 6 are operated without gap and the valve clearance is continuously automatically compensated. At this time, under the action of the exhaust cam 22, the exhaust rocker arm assembly 12 operates according to the profile track of the exhaust cam 22, and through the exhaust valve bridge 6, the exhaust valve assembly 7 operates in a normal state.

[0069] Brake rocker arm assembly 13:

[0070] Under the action of the brake rocker arm roller return spring sheet (it can also be a pressure plate spring assembly), the roller assembly of the brake rocker arm assembly 13 is always tangent to the brake cam 23 during operation, so that the brake rocker arm assembly 13 runs along the trajectory of the brake cam 23.

[0071] 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.

[0072] (4) When the internal combustion engine exhaust brake is in operation:

[0073] Intake rocker arm assembly 11:

[0074] Under the action of the intake cam 21 , the intake rocker arm assembly 11 operates according to the profile track of the intake cam 21 , and through the intake valve bridge 4 , the intake valve assembly 5 still operates in a normal state.

[0075] Exhaust rocker arm assembly 12:

[0076] When the internal combustion engine needs to perform in-cylinder exhaust brake work, the solenoid valve assembly 8 is started, so that the brake high-pressure oil enters the control valve high-pressure oil chamber 12o through the rocker shaft brake oil passage 1b in the rocker shaft 1, and the control valve spool 12k quickly compresses the control valve return spring 12l. At this time, the lubricating oil is cut off from entering the hydraulic tappet low-pressure oil chamber 12m, and the hydraulic tappet high-pressure oil chamber 12n cannot be replenished with lubricating oil. At the same time, the high-pressure oil in the hydraulic tappet high-pressure oil chamber 12n is drained through the oil drain passage. Under the action of the spring pressure plate 92, the spring 93, and the spring seat 94 on the rear exhaust rocker arm 12b, the roller assembly 91 and the exhaust cam 22 are always tangent during the movement.

[0077] At this time, the tappet 12d installed on the front exhaust rocker arm 12a is connected to the ball head 12e and the sliding connection 12f, and under the joint action of the tappet support spring 12j and the rear exhaust rocker arm 12b, the tappet 12d reciprocates in the tappet housing 12c. Due to the loss of the rigidity of the hydraulic tappet assembly, the sliding member at the front end of the front exhaust rocker arm 12a cannot open the exhaust valve bridge 6, thereby achieving the purpose of the exhaust rocker arm assembly 12 being unable to open the non-braking end exhaust valve during braking, so that the internal combustion engine can achieve the purpose of high-power braking and increase the life of the exhaust valve 71 and the exhaust valve bridge 6.

[0078] Since the exhaust rocker arm assembly 12 adopts the stop valve compensation technology, the exhaust valve bridge 6 will not have the potential risk of jumping out under braking, and the engine noise is reduced and the NVH is improved.

[0079] Brake rocker arm assembly 13:

[0080] When the internal combustion engine needs to perform in-cylinder exhaust braking, the solenoid valve assembly 8 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. At the same time, the steel ball 35 engaged with the conical surface 31b is opened, and the one-way valve spring 36 on the one-way valve seat 34 is compressed, so that the high-pressure oil quickly enters the upper 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. 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, entering the cylinder braking operation. At this time, under the action of the brake rocker arm roller return spring sheet (it can also be a 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.

[0081] (5) When the exhaust brake of the internal combustion engine is released:

[0082] Intake rocker arm assembly 11:

[0083] Under the action of the intake cam 21 , the intake rocker arm assembly 11 operates according to the profile track of the intake cam 21 , and through the intake valve bridge 4 , the intake valve assembly 5 still operates in a normal state.

[0084] Exhaust rocker arm assembly 12:

[0085] When the internal combustion engine needs to cancel the in-cylinder exhaust brake, the solenoid valve assembly 8 is closed, so that the brake high-pressure oil cannot enter the control valve high-pressure oil chamber 12o through the rocker shaft brake oil passage 1b in the rocker shaft 1. At this time, there is no lubricating oil pressure in the control valve high-pressure oil chamber 12o, so that the control valve core 12k is quickly reset under the action of the control valve return spring 12l.

[0086] At this time, the exhaust rocker arm oil drain channel is quickly cut off, so that the hydraulic tappet high-pressure oil chamber 12n resumes function and enters a normal working state. At the same time, the lubricating oil quickly enters the rocker arm shaft lubricating oil channel 1a, enters the hydraulic tappet low-pressure oil chamber 12m through the oil inlet channel, passes through the tappet oil channel 12h, opens the one-way valve steel ball 12i, and the lubricating oil enters the hydraulic tappet high-pressure oil chamber 12n. Under the joint action of the high-pressure oil in the hydraulic tappet high-pressure oil chamber 12n and the tappet support spring 12j, the front exhaust rocker arm 12a is quickly pushed to rotate through the tappet 12d, the connecting ball head 12e, the sliding connector 12f, and the rotation of the rear exhaust rocker arm 12b and the pin shaft. On the rear exhaust rocker arm 12b, under the action of the spring pressure plate 92, the spring 93, and the spring seat 94, the roller assembly 91 and the exhaust cam 22 are always tangent during the movement, so that the sliding member at the front end of the exhaust rocker arm assembly 12 is tangent to the exhaust valve bridge 6, and the gap between the sliding member and the exhaust valve bridge 6 is quickly eliminated to form a rigid body, so that the exhaust rocker arm assembly 12 and the exhaust valve bridge 6 are operated without gap and the valve clearance is continuously automatically compensated. At this time, under the action of the exhaust cam 22, the exhaust rocker arm assembly 12 operates according to the profile track of the exhaust cam 22, and through the exhaust valve bridge 6, the exhaust valve assembly 7 operates in a normal state.

[0087] Brake rocker arm assembly 13:

[0088] When the internal combustion engine needs to cancel the in-cylinder exhaust brake, the solenoid valve assembly 8 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, 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 solenoid valve oil discharge hole through the oil channel, and the original ignition working state of the internal combustion engine is restored.

[0089] At this time, the exhaust valve 71 on the brake side moves upward quickly under the action of the exhaust valve spring 72, restores the original working state of the brake pin 61, and maintains the original gap with the lower end surface of the tappet 33. At this time, under the action of the brake rocker roller return spring sheet (or the pressure plate spring assembly), the brake rocker assembly 13 makes the roller assembly of the brake rocker assembly 13 and the brake cam 23 always tangent during the operation, so that the brake rocker 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.

[0090] The internal combustion engine cylinder brake combined rocker arm system of the present invention enables the internal combustion engine to achieve high-power braking, has a reasonable structure, and the exhaust rocker arm assembly includes a front exhaust rocker arm, a rear exhaust rocker arm and a hydraulic tappet assembly, making the structure more reasonable and compact. At the same time, the exhaust rocker arm assembly has an automatic exhaust valve clearance compensation function through the arrangement of the hydraulic tappet assembly, so that the engine manufacturing company does not need to adjust the exhaust valve clearance when assembling the exhaust rocker arm assembly, and the user does not need to adjust the exhaust valve clearance in the future, which reduces the operating cost, improves the operating efficiency of the engine, and solves the potential risk of exhaust valve bridge jumping caused by poor exhaust valve follow-up due to cylinder braking, which can reduce the noise of engine operation and improve NVH.

[0091] 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 system, 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 (8), 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) includes a front exhaust rocker arm (12a) and a rear exhaust rocker arm (12b), a hydraulic tappet assembly is arranged between the front exhaust rocker arm (12a) and the rear exhaust rocker arm (12b), the hydraulic tappet assembly includes a tappet housing (12c), a tappet (12d), a connecting ball head (12e) and a sliding connection (12f), the tappet housing (12c) is fixed on the front exhaust rocker arm (12a), and the sliding connection (12f) is abutted against the rear exhaust rocker arm (12b) , one end of the connecting ball head (12e) is assembled on the tappet (12d), and the other end cooperates with the sliding connection (12f), the tappet (12d) is provided with a tappet oil passage (12h), a one-way valve steel ball (12i) is installed on the tappet oil passage (12h), a tappet support spring (12j) is arranged between the tappet (12d) and the tappet housing (12c), and a hydraulic tappet low-pressure oil chamber (12m) and a hydraulic tappet high-pressure oil chamber (12n) are respectively formed on both sides of the one-way valve steel ball (12i); The exhaust rocker arm assembly (12) is also provided with a control valve assembly, the control valve assembly comprising a control valve core (12k), a control valve return spring (12l) is provided between one end of the control valve core (12k) and the exhaust rocker arm assembly (12), and a control valve high-pressure oil chamber (12o) is formed between the other end of the control valve core (12k) and the exhaust rocker arm assembly (12); When the internal combustion engine needs to perform in-cylinder exhaust braking, the solenoid valve assembly (8) is started, and the brake high-pressure oil enters the control valve high-pressure oil chamber (12o) through the rocker shaft brake oil passage (1b) in the rocker shaft (1), causing the control valve core (12k) to compress the control valve return spring (12l), cutting off the lubricating oil from entering the hydraulic tappet low-pressure oil chamber (12m), and the high-pressure oil in the hydraulic tappet high-pressure oil chamber (12n) is drained through the oil drain passage.

2. The internal combustion engine cylinder brake combined rocker arm system according to claim 1, characterized in that: A roller assembly (91) is arranged at the rear end of the rear exhaust rocker arm (12b), and a pressure plate spring assembly consisting of a spring pressure plate (92), a spring (93) and a spring seat (94) is arranged above the roller assembly (91). Under the action of the pressure plate spring assembly, the roller assembly (91) is always tangentially matched with the exhaust cam (22).

3. The internal combustion engine cylinder brake combined rocker arm system according to claim 2, 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), and 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), 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).

4. The internal combustion engine cylinder brake combined rocker arm system according to claim 3, 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).

5. The internal combustion engine cylinder brake combined rocker arm system according to claim 4, 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).

6. The internal combustion engine cylinder brake combined rocker arm system according to claim 5, characterized in that: 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).

7. An internal combustion engine cylinder brake combined rocker arm system according to any one of claims 1 to 6, characterized in that: The exhaust valve bridge (6) is provided with a brake pin (61) which matches with the tappet (33) of the brake (3).

8. The internal combustion engine cylinder brake combined rocker arm system according to claim 7, characterized in that: The upper end of the brake pin (61) is provided with an anti-slipping 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-slipping portion (61a).

9. The internal combustion engine cylinder brake combined rocker arm system 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 internal combustion engine cylinder brake combined rocker arm system 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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