Transverse piston type valve bridge arrangement with variable height

Abstract

A variable-height transverse piston valve bridge assembly arranged between a rocker arm (1) and a valve (2), wherein the center of the rocker arm (1) is provided with a rocker arm shaft (1.1), one end of the rocker arm (1) is provided with a rocker arm roller (3), the other end of the rocker arm (1) is provided with an adjusting pin (4), and the rocker arm roller (3) is in close contact with a cam disk (5), wherein the valve bridge arrangement further comprises a valve bridge (6), the valve bridge (6) encloses a piston (7), the piston (7) is in close connection with the adjusting bolt (4), the valve bridge (6) is provided with a valve groove (6.1), and one end of the valve (2) is arranged in the valve groove (6.1); wherein the valve bridge (6) is provided with a vertical piston cylinder (6.2) and a transverse plunger cylinder (6.3), the piston (7) is arranged in the vertical piston cylinder (6.2), a piston spring (7.1) is arranged between the piston (7) and the vertical piston cylinder (6.2), and the lower part of the vertical piston cylinder (6.2) is provided with a piston passage opening (6.4); wherein the transverse plunger cylinder (6.3) is arranged on the lower part of the vertical piston cylinder (6.2), the transverse plunger cylinder (6.3) is provided with a plunger (8) and a plug (9), a plunger spring (8.1) is arranged between the plunger (8) and the plug (9), the piston passage opening (6.4) is arranged in a radial direction of the plunger (8); wherein the rocker arm shaft (1.1) is provided with a rocker arm shaft control oil passage (1.1a), the rocker arm (1) is provided with a rocker arm oil passage (1a), the adjusting bolt (4) is provided with an adjusting bolt oil passage (4a), the piston (7) is provided with a piston oil passage (7a) and a piston valve bridge connection oil passage (7b), the valve bridge (6) is provided with a valve bridge oil passage (6a) and the transverse plunger cylinder (6.3) is provided with a plunger oil chamber (6.3a); wherein the rocker arm shaft control oil passage (1.1a) is connected to the plunger oil chamber (6.3a) successively via the rocker arm oil passage (1a), the adjusting bolt oil passage (4a), the piston oil passage (7a), the piston valve bridge connection oil passage (7b) and the valve bridge oil passage (6a); wherein the plunger (8) is arranged between the plunger oil chamber (6.3a) and the plug (9); characterized in that one end of the piston (7) is furthermore provided with a piston rod (7.2) and the piston spring (7.1) is pushed onto the piston rod (7.2); the plunger (8) is provided with a piston groove (8.2) and a piston bore (8.3), the piston groove (8.2) is opposite the piston rod (7.2) and the direction of the piston bore (8.3) is the same as that of the piston passage opening (6.4); and an annular grooved passage (6.2a) is formed between the valve bridge oil passage (6a) and the inner wall of the vertical piston cylinder (6.2), and the piston valve bridge connection oil passage (7b) is always in contact with the annular grooved passage (6.2a) when the piston (7) moves axially; wherein the piston bore (8.3) is arranged in the piston groove (8.2) and the valve bridge arrangement is configured such that in operation the piston rod (7.2) always projects into the piston groove (8.2) to prevent the plunger (8) from rotating due to the force between the inner wall of the piston groove (8.2) and the piston rod (7.2), so that the limiting effect on the plunger (8) is achieved, such that when the plunger (8) moves to the side of the plug (9), the piston rod (7.2) is opposite the piston bore (8.3); wherein the piston passage opening (6.4) radially penetrates the transverse plunger cylinder (6.3) and the valve bridge assembly is configured such that when the piston rod (7.2) is opposite the piston bore (8.3) and the cam disk (5) rotates to successively push the rocker arm (1), the adjusting bolt (4), an elephant's foot (10) and the piston (7), the piston rod (7.2) passes through the piston passage opening (6.4) and moves downwards without touching the plunger (8), and the valve bridge (6) does not push the valve (2) further until the piston spring sleeve (7.3) touches the lower surface of the vertical piston cylinder (6.2).

Description

Field of the invention

[0001] The present invention relates to the technical field of a valve mechanism for vehicle engines, in particular to a cross-piston type variable height valve bridge assembly. Background of the invention

[0002] The variable valve lift mechanism can generally be implemented using variable cams, variable rocker arms, and so on. The variable cam and variable rocker arms are structurally complex and must be implemented by changing the position of the cam or the force position of the rocker arm, which often requires complex transmission mechanisms and servo motors for control. Existing variable-height valve bridges are generally redesigned and adjusted using steel balls, pins, and so on.

[0003] Currently, variable valve lift technology is generally implemented using variable cams and variable rocker arms, which have a complex mechanism, are expensive, and have a low degree of customization. Existing variable-height valve bridges are generally converted and fixed by steel balls and pins. These parts have a small load area, high contact loads, easy wear, and poor reliability and durability.

[0004] The document DE102011052246A1 discloses a valve bridge arrangement of the transverse piston type. Summary of the invention

[0005] The purpose of the present invention is to provide a cross-piston type variable height valve bridge assembly which changes the operating height, force state and force area of ​​the valve bridge assembly by changing the relative position of the piston and the plunger, realizes the movement loss of the cam mechanism, and thereby realizes the variable valve lift with simple structure, small volume, light weight, good reliability and low cost.

[0006] The object is achieved by a valve bridge arrangement according to claim 1. Preferred embodiments are described in the dependent claims.

[0007] To achieve the above purpose, the present invention provides a cross-piston type variable height valve bridge assembly disposed between a rocker arm and a valve, wherein the center of the rocker arm is provided with a rocker shaft, one end of the rocker arm is provided with a rocker roller, the other end of the rocker arm is provided with an adjusting pin, and the rocker roller is in close contact with a cam plate; the valve bridge assembly further comprises a valve bridge, the valve bridge surrounds a piston, the piston is in close contact with the adjusting pin, the valve bridge is provided with a valve groove, and one end of the valve is disposed in the valve groove;the valve bridge is provided with a vertical piston cylinder and a transverse plunger cylinder, the piston is arranged in the vertical piston cylinder, a piston spring is arranged between the piston and the vertical piston cylinder, one end of the piston is further provided with a piston rod, the piston spring is pushed onto the piston rod and the lower part of the vertical piston cylinder is provided with a piston through-hole;the transverse plunger cylinder is arranged at the lower part of the vertical piston cylinder, the transverse plunger cylinder is provided with a plunger and a plug, a plunger spring is arranged between the plunger and the plug, the piston through hole is arranged in a radial direction of the plunger, the plunger is provided with a piston groove and a piston bore, the piston groove is opposite to the piston rod, and the direction of the piston bore is the same as that of the piston through hole; the rocker arm shaft is provided with a rocker arm shaft control oil passage, the rocker arm is provided with a rocker arm oil passage, the adjusting bolt is provided with an adjusting bolt oil passage, the piston is provided with a piston oil passage and a piston valve bridge connection oil passage, the valve bridge is provided with a valve bridge oil passage, and the transverse plunger cylinder is provided with a plunger oil chamber;The rocker arm shaft control oil passage communicates with the plunger oil chamber sequentially via the rocker arm oil passage, the adjusting pin oil passage, the piston oil passage, the piston valve bridge connecting oil passage, and the valve bridge oil passage; the plunger is disposed between the plunger oil chamber and the plug; and an annular groove passage is formed between the valve bridge oil passage and the inner wall of the vertical piston cylinder, and the piston valve bridge connecting oil passage always communicates with the annular groove passage when the piston moves axially. The outer side of the piston is provided with an annular groove passage so that the piston valve bridge connecting oil passage always communicates with the annular groove passage when the piston rotates.

[0008] Furthermore, one end of the piston is provided with an elephant foot, the adjusting bolt is arranged in the elephant foot, the elephant foot is provided with an elephant foot oil passage, and the adjusting bolt oil passage communicates with the piston oil passage through the elephant foot oil passage. In this way, under the action of the piston spring, the piston top is always in close contact with the elephant foot to ensure that sufficient engine oil can enter the piston oil passage from the elephant foot oil passage, preventing engine oil leakage and maintaining sufficient engine oil pressure, thereby quickly pushing the plunger to move in a locking direction to switch the state.

[0009] Furthermore, the opening of the vertical piston cylinder is provided with a retaining ring, and the piston is arranged in the retaining ring. Thus, in a free state, i.e., when the valve bridge assembly is not mounted on the engine, the valve bridge assembly is held in place as a whole to prevent the piston from jumping out of a piston cavity under the action of the piston spring.

[0010] Furthermore, one end of the piston is provided with a piston spring sleeve, and one end of the piston spring is housed in the piston spring sleeve. This utilizes the axial limiting effect of the piston spring sleeve to ensure that the piston spring does not overlap during operation, thus ensuring the service life of the piston spring.

[0011] Furthermore, one end of the plunger is provided with a plunger spring sleeve, and one end of the plunger spring is housed within the plunger spring sleeve. This utilizes the axial limiting effect of the plunger spring sleeve to ensure that the plunger spring does not overlap during operation, thus ensuring the service life of the plunger spring.

[0012] Furthermore, the plunger oil chamber is equipped with a plunger limiting plate, and the plunger fits tightly against the limiting plate. This allows the plunger limiting plate to limit excessive movement of the plunger, ensuring that the relative position of the plunger and the piston rod always remains within the reasonable design range under normal working conditions.

[0013] In addition, the valve bridge is provided with a plurality of valve grooves, each of which is provided with a valve, and the vertical piston cylinder is arranged in the center of the plurality of valve grooves. Such a structure can ensure the balance of forces on the entire valve bridge, making the structure even more rational.

[0014] According to the invention, the piston bore is arranged in the piston groove. When the height of the valve bridge needs to be lowered, the piston moves the smallest distance in the transverse plunger cylinder, thereby increasing the stability of the entire structure.

[0015] According to the invention, the piston through-hole penetrates the transverse plunger cylinder in a radial direction. This allows the piston rod, if long, to pass through the piston through-hole, and the piston through-hole can drain the engine oil leaking from the plunger oil passage and the piston valve bridge connecting oil passage into the center of the transverse plunger cylinder.

[0016] Preferably, the transverse plunger cylinder is provided with an oil drain port. This allows the oil drain port to be used to drain the engine oil leaking from the plunger and the air on the blocked side of the plunger.

[0017] The present invention has the following advantages: 1. By setting the variable height of the valve bridge to different values, the structure of the present invention can be used for variable valve displacement devices of various engines, high-performance braking devices of engines, or the integration of the two; 2. Compared with other similar actuators, it has the advantages of simple structure, easy installation and high reliability; 3. The valve bridge is universally applicable and can be used for all four-valve engines. Short description of the drawings Fig. 1 is a schematic representation of an installation structure according to the present invention; Fig. 2 is a schematic diagram of an installation structure under another operating condition of the present invention; Fig. 3 is a schematic representation of the internal structure of a valve bridge in the free state; Fig. 4 is a schematic representation of the internal structure of a valve bridge during valve clearance adjustment; Fig. 5 is a schematic diagram of the internal structure of a valve bridge during valve height switching; Fig. 6 is a schematic diagram of the internal structure of a valve bridge of Embodiment 2; Fig. 7 is a view of Fig. 6 from the left; Fig. 8 is a schematic diagram of the internal structure of a transverse plunger cylinder in Embodiment 2.

[0018] In the figures: 1-Rocker arm (comprising: 1a-Rocker arm oil passage, 1.1-Rocker arm shaft, and 1.1a-Rocker arm shaft control oil passage), 2-Valve, 3-Rocker arm roller, 4-Adjusting pin (comprising: 4a-Adjusting pin oil passage), 5-Cam disc, 6-Valve bridge (comprising: 6a-Valve bridge oil passage, 6.1-Valve grooves, 6.2-Vertical piston cylinder, 6.2a-Annular groove passage, 6.2.1-Retaining ring, 6.3-Transverse plunger cylinder, 6.3a-Plunger oil chamber, 6.3.1-Plunger limiting plate, 6.3.2-Oil drain hole, 6.4-Piston through hole), 7-Piston (comprising: 7a-piston oil passage, 7b-piston valve bridge connection oil passage, 7.1-piston spring, 7.2-piston rod, 7.3-piston spring sleeve), 8-plunger (comprising: 8.1-plunger spring, 8.2-piston groove, 8.3-piston bore, 8.4-plunger spring sleeve), 9-plug, 10-elephant foot (comprising: 10a-elephant foot oil passage). Detailed description of the drawings

[0019] The present invention will be described in more detail below with reference to the drawings in conjunction with the embodiments. Embodiment 1

[0020] As in the Fig. 1-5, the figure shows a cross-piston type variable height valve bridge assembly arranged between a rocker arm 1 and a valve 2, wherein the center of the rocker arm 1 is provided with a rocker shaft 1.1, one end of the rocker arm 1 is provided with a rocker roller 3, the other end of the rocker arm 1 is provided with an adjusting pin 4, and the rocker roller 3 is in close contact with a cam 5; the valve bridge assembly further comprises a valve bridge 6, the valve bridge 6 surrounds a piston 7, the piston 7 is in close contact with the adjusting pin 4, the valve bridge 6 is provided with a valve groove 6.1, and one end of the valve 2 is arranged in the valve groove 6.1; the valve bridge 6 is provided with a vertical piston cylinder 6.2 and a transverse plunger cylinder 6.3, the piston 7 is arranged in the vertical piston cylinder 6.2, a piston spring 7.1 is arranged between the piston 7 and the vertical piston cylinder 6.2, one end of the piston 7 is further provided with a piston rod 7.2, the piston spring 7.1 is pushed onto the piston rod 7.2, and the lower part of the vertical piston cylinder 6.2 is provided with a piston through-hole 6.4; The transverse plunger cylinder 6.3 is arranged at the lower part of the vertical piston cylinder 6.2. The transverse plunger cylinder 6.3 is provided with a plunger 8 and a plug 9, a plunger spring 8.1 is arranged between the plunger 8 and the plug 9, the piston through hole 6.4 is arranged in the radial direction of the plunger 8, the plunger 8 is provided with a piston groove 8.2 and a piston bore 8.3, the piston groove 8.2 is opposite to the piston rod 7.2, and the direction of the piston bore 8.3 is the same as that of the piston through hole 6.4; the rocker arm shaft 1.1 is provided with a rocker arm shaft control oil passage 1.1a, the rocker arm 1 is provided with a rocker arm oil passage 1a, the adjusting pin 4 is provided with an adjusting pin oil passage 4a, the piston 7 is provided with a piston oil passage 7a and a piston valve bridge connection oil passage 7b, the valve bridge 6 is provided with a valve bridge oil passage 6a, and the transverse plunger cylinder 6.3 is provided with a plunger oil chamber 6.3a; the rocker arm shaft control oil passage 1.1a communicates with the plunger oil chamber 6.3a sequentially via the rocker arm oil passage 1a, the adjusting pin oil passage 4a, the piston oil passage 7a, the piston valve bridge connection oil passage 7b, and the valve bridge oil passage 6a; the plunger 8 is arranged between the plunger oil chamber 6.3a and the plug 9; and between the valve bridge oil passage 6a and the inner wall of the vertical piston cylinder 6.2, an annular groove passage 6.2a, and the piston valve bridge connecting oil passage 7b is always in communication with the annular groove passage 6.2a when the piston 7 moves axially.

[0021] One end of the piston 7 is provided with an elephant foot 10, the adjusting bolt 4 is arranged in the elephant foot 10, the elephant foot 10 is provided with an elephant foot oil passage 10a, and the adjusting bolt oil passage 4a communicates with the piston oil passage 7a through the elephant foot oil passage 10a. The opening of the vertical piston cylinder 6.2 is provided with a retaining ring 6.2.1, and the piston 7 is arranged in the retaining ring 6.2.1. One end of the piston 7 is provided with a piston spring sleeve 7.3, and one end of the piston spring 7.1 is arranged in the piston spring sleeve 7.3. One end of the plunger 8 is provided with a plunger spring sleeve 8.4, and one end of the plunger spring 8.1 is arranged in the plunger spring sleeve 8.4. The plunger oil chamber 6.3a is provided with a plunger limiting plate 6.3.1, and the plunger 8 fits tightly against the plunger limiting plate 6.3.1. The valve bridge 6 is provided with a plurality of valve grooves 6.1, each valve groove 6.1 is provided with a valve 2, and the vertical piston cylinder 6.2 is arranged in the center of the plurality of valve grooves 6.1. The piston bore 8.3 is arranged in the piston groove 8.2. The piston through-hole 6.4 radially penetrates the transverse plunger cylinder 6.3. The transverse plunger cylinder 6.3 is provided with an oil drain hole 6.3.2.

[0022] Piston 7 is in a clearance fit with the vertical piston cylinder 6.2, and tappet 8 is in a clearance fit with the transverse plunger cylinder 6.3. The retaining ring 6.2.1 is press-fitted into the vertical piston cylinder 6.2 of the valve bridge 6 to limit the position of piston 7, and plug 9 is connected to the transverse plunger cylinder 6.3 by threads.

[0023] During operation, the piston rod 7.2 always projects into the piston groove 8.2 to prevent the plunger 8 from rotating by the force between the inner wall of the piston groove 8.2 and the piston rod 7.2, so that the limiting effect on the plunger 8 is achieved, so that when the plunger 8 moves to the side of the plug 9, the piston rod 7.2 is opposite the piston bore 8.3. Embodiment 2 (not covered by claim 1)

[0024] As in the Fig. 6-8, the remaining structures are the same as in Embodiment 1, except that the piston groove 8.2 on the plunger 8 is omitted, a bolt hole is provided on the side of the plunger 8, and a restricting groove is provided on the inner wall of the transverse plunger cylinder 6.3. The positioning pin is press-fitted into the bolt hole of the plunger, and at the same time, the other end of the positioning pin is inserted into the restricting groove. In this way, the positioning pin can prevent the plunger 8 from rotating along the axis to ensure that when the plunger moves toward the plug 9 under the engine oil pressure to contact the plug 9, the piston rod 7.2 faces the piston bore 8.3 and can smoothly enter the piston bore 8.3 through the piston through hole 6.4. At this time, in the normal operating state (iein the state where the valve bridge is high), the working surface of the plunger changes from the piston groove 8.2 to the outer wall of the plunger 8, and the piston rod 7.2 contacts the outer wall of the plunger 8 for movement and power transmission.

[0025] The cross-piston type variable height valve bridge assembly of the present invention is arranged on the valve mechanism of the engine, the solenoid valve controls the rocker shaft to control the opening and closing of the oil passage 1.1a, so that the plunger 8 is in different positions, so that the position of the piston 7 is changed, and then the movement law of the valve 2 is changed.

[0026] Actual use involves the following steps: 1. Free state

[0027] As in Fig. 3, that is, when the cross-piston type variable height valve bridge assembly of the present invention is not mounted on the engine, there is no engine oil in the piston oil passage 7a, the valve bridge oil passage 6a, and the plunger oil chamber 6.3a, or the engine oil pressure is 0. At this time, the plunger 8 moves to the right under the elastic force of the plunger spring 8.1 until the right side surface of the plunger 8 closely contacts the plunger restrictor plate 6.3.1 on the valve bridge 6. At this time, the piston rod 7.2 at the lower end of the piston 7 is opposite to the working surface (the outer wall of the piston groove 8.2 or the plunger 8) of the plunger 8, and the distance between the lower surface of the piston rod 7.2 and the working surface of the plunger 8 is A1.

[0028] At this time, the piston 7 moves upward under the elastic force of the piston spring 7.1 to closely fit the retaining ring 6.2.1, the distance between the piston spring sleeve 7.3 and the lower surface of the vertical piston cylinder 6.2 is B1, and the distance between the piston 7 and the retaining ring 6.2.1 is C1 = 0. The height of the valve bridge assembly is H. 2. Assembly state

[0029] As in Fig. As shown in Figure 4, after mounting the cross-piston type variable height valve bridge assembly of the present invention on the engine, the valve clearance is adjusted to X. At this time, the distance between the piston rod 7.2 and the working surface of the plunger 8 is A2=A1-X, the distance between the piston 7 and the retaining ring 6.2.1 changes to C2=C1+X=X, and the distance between the piston spring sleeve 7.3 and the lower surface of the vertical piston cylinder 6.2 changes to B2=B1-C2.

[0030] At this time, the piston 7 is pushed by the piston spring 7.1 to ensure that there is a clearance A2 between the piston 7 and the working surface of the plunger 8 when the rocker roller 3 is opposed to the base circle of the cam 5, so that the plunger 8 can slide smoothly to the left and right along the axial direction. 3. Normal operating condition

[0031] When the engine is in normal working condition, the solenoid valve does not turn on, the rocker arm shaft control oil passage 1.1a is depressurized, and the plunger 8 stays close to the plunger limiting plate 6.3.1 under the action of the plunger spring 8.1. When the cam 5 rotates, the rocker arm 1, the adjusting pin 4 and the elephant foot 10 are sequentially displaced, then the elephant foot 10 pushes the piston 7 downward, the piston rod 7.2 overcomes the elastic force of the piston spring 7.1 and contacts the working surface of the plunger 8, then the piston 7.2 pushes the plunger 8, the plunger 8 sequentially pushes the valve bridge 6 and the valve 2 to move the valve 2 downward. At this time, all the strokes of the cam 5 are transmitted to the valve 2. The working height of the valve bridge assembly is W=HX. 4. Reducing the height of the valve bridge

[0032] As in Fig.As shown, the solenoid valve turns on when the engine needs to reduce the valve lift, and the engine oil in the rocker arm shaft control oil passage 1.1a finally enters the plunger oil chamber 6.3a, successively through the rocker arm oil passage 1a, the adjusting pin oil passage 4a, the elephant foot oil passage 10a, the piston oil passage 7a, the piston valve bridge connecting oil passage 7b, and the valve bridge oil passage 6a. At this time, the plunger 8 is pushed to the left by the engine oil against the elastic force of the plunger spring 8.1 until the plunger spring sleeve 8.4 on the left side of the plunger 8 fits snugly against the plug 9.

[0033] At this time, the piston rod 7.2 is opposite the piston bore 8.3. When the cam 5 rotates to push the rocker arm 1, the adjusting pin 4, the elephant foot 10, and the piston 7 in sequence, the piston rod 7.2 passes through the piston through hole 6.4 and moves downward without touching the plunger 8, and the valve bridge 10 does not push the valve 2 further until the piston spring sleeve 7.3 touches the lower surface of the vertical piston cylinder 6.2.

[0034] In this way, the working height of the valve bridge arrangement is reduced to W=H-B2-X, and only a part of the stroke of the cam disc 5 is transmitted to the valve 2.

[0035] It should be noted that relationship terms such as "first" and "second" serve only to distinguish one entity or process from another entity or process in the present application and do not necessarily require or imply any such actual relationship or sequence between those entities or processes. Furthermore, the terms "include," "comprising," or other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus comprising a series of elements includes not only those elements but also those not expressly listed, or further includes elements inherent in the process, method, article, or apparatus. Unless otherwise limited, the elements defined by the phrase "comprising" include...“ do not exclude the presence of other similar elements in the process, method, article or device incorporating those elements.

Claims

[1] A cross-piston type variable height valve bridge assembly arranged between a rocker arm (1) and a valve (2), wherein the center of the rocker arm (1) is provided with a rocker shaft (1.1), one end of the rocker arm (1) is provided with a rocker roller (3), the other end of the rocker arm (1) is provided with an adjusting bolt (4), and the rocker roller (3) is in close contact with a cam disc (5), wherein the valve bridge arrangement further comprises a valve bridge (6), the valve bridge (6) encloses a piston (7), the piston (7) is in close connection with the adjusting bolt (4), the valve bridge (6) is provided with a valve groove (6.1), and one end of the valve (2) is arranged in the valve groove (6.1); wherein the valve bridge (6) is provided with a vertical piston cylinder (6.2) and a transverse plunger cylinder (6.3), the piston (7) is arranged in the vertical piston cylinder (6.2), a piston spring (7.1) is arranged between the piston (7) and the vertical piston cylinder (6.2), and the lower part of the vertical piston cylinder (6.2) is provided with a piston passage opening (6.4); wherein the transverse plunger cylinder (6.3) is arranged on the lower part of the vertical piston cylinder (6.2), the transverse plunger cylinder (6.3) is provided with a plunger (8) and a plug (9), a plunger spring (8.1) is arranged between the plunger (8) and the plug (9), the piston passage opening (6.4) is arranged in a radial direction of the plunger (8); wherein the rocker arm shaft (1.1) is provided with a rocker arm shaft control oil passage (1.1a), the rocker arm (1) is provided with a rocker arm oil passage (1a), the adjusting bolt (4) is provided with an adjusting bolt oil passage (4a), the piston (7) is provided with a piston oil passage (7a) and a piston valve bridge connection oil passage (7b), the valve bridge (6) is provided with a valve bridge oil passage (6a) and the transverse plunger cylinder (6.3) is provided with a plunger oil chamber (6.3a); wherein the rocker arm shaft control oil passage (1.1a) is connected to the plunger oil chamber (6.3a) sequentially via the rocker arm oil passage (1a), the adjusting pin oil passage (4a), the piston oil passage (7a), the piston valve bridge connection oil passage (7b) and the valve bridge oil passage (6a); wherein the plunger (8) is arranged between the plunger oil chamber (6.3a) and the plug (9); characterized by , that one end of the piston (7) is further provided with a piston rod (7.2) and the piston spring (7.1) is pushed onto the piston rod (7.2); the plunger (8) is provided with a piston groove (8.2) and a piston bore (8.3), the piston groove (8.2) is opposite the piston rod (7.2) and the direction of the piston bore (8.3) is the same as that of the piston through-hole (6.4); and an annular groove passage (6.2a) is formed between the valve bridge oil passage (6a) and the inner wall of the vertical piston cylinder (6.2), and the piston valve bridge connecting oil passage (7b) is always connected to the annular groove passage (6.2a) when the piston (7) moves axially; wherein the piston bore (8.3) is arranged in the piston groove (8.2) and the valve bridge arrangement is configured such that, in operation, the piston rod (7.2) always projects into the piston groove (8.2) to prevent the plunger (8) from rotating by the force between the inner wall of the piston groove (8.2) and the piston rod (7.2), so that the limiting effect on the plunger (8) is achieved, so that when the plunger (8) moves to the side of the plug (9), the piston rod (7.2) is opposite the piston bore (8.3); wherein the piston through-hole (6.4) radially penetrates the transverse plunger cylinder (6.3) and the valve bridge arrangement is configured such that when the piston rod (7.2) is opposite the piston bore (8.3) and the cam disc (5) rotates to successively push the rocker arm (1), the adjusting bolt (4), an elephant foot (10) and the piston (7), the piston rod (7.2) passes through the piston through-hole (6.4) and moves downwards without touching the plunger (8), and the valve bridge (6) does not push the valve (2) any further until the piston spring sleeve (7.3) touches the lower surface of the vertical piston cylinder (6.2). [2] The cross-piston type variable height valve bridge assembly according to claim 1, wherein one end of the piston (7) is provided with the elephant foot (10), the adjusting bolt (4) is arranged in the elephant foot (10), the elephant foot (10) is provided with an elephant foot oil passage (10a), and the adjusting bolt oil passage (4a) is communicated with the piston oil passage (7a) through the elephant foot oil passage (10a). [3] The variable height cross piston type valve bridge assembly according to claim 2, wherein the opening of the vertical piston cylinder (6.2) is provided with a retaining ring (6.2.1) and the piston (7) is arranged in the retaining ring (6.2.1). [4] The cross-piston type variable height valve bridge assembly according to claim 3, wherein one end of the piston (7) is provided with a piston spring sleeve (7.3) and one end of the piston spring (7.1) is arranged in the piston spring sleeve (7.3). [5] The cross-piston type variable height valve bridge assembly according to any one of claims 1 to 4, wherein one end of the plunger (8) is provided with a plunger spring sleeve (8.4), and one end of the plunger spring (8.1) is arranged in the plunger spring sleeve (8.4). [6] The cross-piston type variable height valve bridge assembly according to claim 5, wherein the plunger oil chamber (6.3a) is provided with a plunger limiting plate (6.3.1) and the plunger (8) is tightly fitted to the plunger limiting plate (6.3.1). [7] The cross-piston type variable height valve bridge assembly according to claim 6, wherein the valve bridge (6) is provided with a plurality of valve grooves (6.1), each valve groove (6.1) is respectively provided with the valve (2), and the vertical piston cylinder (6.2) is arranged in the center of the plurality of valve grooves (6.1). [8] The transverse piston type variable height valve bridge assembly according to claim 7, wherein the transverse plunger cylinder (6.3) is provided with an oil drain port (6.3.2).

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