A hydraulic braking engine braking actuator and its application method

Abstract

The present invention discloses a hydraulic braking engine braking actuator, which includes a rocker arm body. A control unit and an execution unit are arranged on the rocker arm body. The axis of the control unit is perpendicular to the rotation direction of the rocker arm body. The execution unit includes an execution piston adjusting screw, an execution piston and an execution piston limit guide sleeve. The execution piston includes an execution piston upper body and an execution piston lower body. The head of the execution piston adjusting screw faces downward. The execution piston limit guide sleeve is slidably connected to the execution piston adjusting screw. An execution piston spring is arranged between the execution piston limit guide sleeve and the head of the execution piston adjusting screw. The execution piston upper body is sleeved on the execution piston adjusting screw. The execution piston lower body is fixed to the execution piston upper body from below. The top of the execution piston is communicated with an execution piston high-pressure oil passage, which can control the lift of the exhaust valve during braking, and at the same time, when not braking, it does not affect the execution mechanism of the exhaust valve lift at all.

Description

Technical Field

[0001] The present invention belongs to the field of valve drive of automobile engines, and more specifically relates to a hydraulic braking engine braking actuator and its application method. Background Art

[0002] With the rapid development of the logistics industry, the efficiency requirements for heavy-duty transport trucks are getting higher and higher. As the truck speed increases, the safety requirements become even higher. Without traditional in-cylinder engine braking, the vehicle's brake pedal needs to be used more frequently, and accidents often occur due to brake pedal failure. To improve the safety of freight trucks, auxiliary braking can be added to the vehicle to reduce the frequency of using the brake pedal, thus ensuring that the brake pedal is in the most recently used state at critical moments. Auxiliary brakes include hydraulic retarders, eddy current retarders, and in-cylinder engine braking. Among them, the first two have high costs and limited operating conditions, and thus have not been widely used. However, in-cylinder engine braking, because it is integrated in the engine and has the same lifespan as the engine, is the most suitable auxiliary braking method in terms of cost, quality, and function.

[0003] The so-called in-cylinder engine braking is to use the vehicle to reverse-drive the engine, convert the high-speed movement of the vehicle into the compressed air energy of the engine, and consume it with the exhaust heat energy of the engine. Therefore, to maximize in-cylinder engine braking, we need to open the exhaust valve at the end of engine intake to form exhaust gas backflow to increase the intake air volume, and at the same time discharge the compressed air near the top dead center of compression. To achieve the opening of the exhaust valve at a fixed moment, an actuator is required to perform this function.

[0004] The existing actuators for in-cylinder braking are mainly divided into mechanical valve drive and hydraulic valve drive. Among them, for mechanical valve drive, the entire structure rigidly transmits force, and the impact force of the system is large. For hydraulic valve drive, due to the compressibility of hydraulic oil, the system can absorb a certain amount of impact, thereby reducing system impact and improving reliability.

[0005] As disclosed in the Chinese patent with the application number 200820072612.1, an engine braking execution unit is characterized in that it consists of an exhaust rocker control valve spring seat, an exhaust rocker control valve spring, an exhaust rocker control valve plunger, a one-way valve assembly, an exhaust rocker braking plunger spring, an exhaust rocker braking plunger, and two circlips for holes. There are upper and lower chambers inside the rocker. In the upper chamber of the rocker, the exhaust rocker control valve plunger is first installed, then the exhaust rocker control valve spring, the exhaust rocker control valve spring seat is installed on the upper part of the spring, and finally it is fixed in the upper chamber of the rocker with a circlip for a hole. In the lower chamber of the rocker, the one-way valve assembly is first installed, which is press-fitted at the top of the lower chamber of the rocker, then the exhaust rocker braking plunger spring, then the exhaust rocker braking plunger, and finally it is fixed in the lower chamber with a circlip for a hole. The above-mentioned patent can squeeze the exhaust rocker braking plunger downward by a certain distance during braking and make it unable to slide. When the braking lift of the camshaft lifts the tappet, two valves can be opened simultaneously to achieve engine braking; during non-braking, the exhaust rocker braking plunger can slide up and down, and this sliding amount can offset the valve lift generated by the braking lift of the camshaft, that is, the camshaft cannot open the valve during the braking lift.

[0006] However, since the directions of the movement axes of the control valve plunger and the braking plunger are the same, and the rocker swings back and forth continuously, the control valve plunger is easily affected by the inertial force of the rocker movement, making the required control position unstable, affecting reliability and braking power; in addition, the initial position of the braking plunger cannot be adjusted as needed; the extension amount of the braking plunger during braking opening can only be controlled by the position of the circlip, and it is difficult to improve the control accuracy. These two factors affect the braking valve lift, and thus also affect the improvement and consistency of braking power. Summary of the Invention

[0007] Aiming at the deficiencies of the prior art, the present invention provides an actuator that can control the lift of the exhaust valve during braking and, at the same time, does not affect the lift of the exhaust valve at all during non-braking.

[0008] To achieve the above object, the present invention provides the following technical solution: An engine braking actuator with hydraulic braking, including a rocker body, a control unit and an execution unit are arranged on the rocker body, and the control unit includes a one-way valve assembly and a control piston assembly.

[0009] One-way valve assembly, which includes a one-way valve body and a one-way valve seal seat. The one-way valve seal seat is fixedly connected to the one-way valve body. A through hole is provided on the one-way valve seal seat. A one-way valve is arranged in the one-way valve body. A one-way valve spring is arranged on the side of the one-way valve facing away from the one-way valve seal seat. The one-way valve abuts against the through hole of the one-way valve seal seat. An oil flow hole is provided on the one-way valve body. An actuator piston high-pressure oil passage communicating with the oil flow hole is provided on the rocker arm body; Control piston assembly, which includes a control piston and a control piston push rod. The control piston push rod is fixedly connected to the control piston. The control piston push rod extends into the through hole of the one-way valve seal seat. A control piston inner spring is arranged on the side of the control piston facing away from the control piston push rod. An oil injection space is left between the control piston and the one-way valve seal seat. A brake oil inlet hole communicating with the oil injection space is provided on the rocker arm body;

[0010] The one-way valve assembly and the control piston assembly are coaxial, and the axis is perpendicular to the rotation direction of the rocker arm body;

[0011] Actuator unit, which includes an actuator piston adjusting screw, an actuator piston and an actuator piston limit guide sleeve. The actuator piston includes an actuator piston upper body and an actuator piston lower body. The head of the actuator piston adjusting screw faces downward. The inner side of the actuator piston limit guide sleeve is slidably connected to the actuator piston adjusting screw. An actuator piston spring is arranged between the actuator piston limit guide sleeve and the head of the actuator piston adjusting screw. The actuator piston upper body is sleeved on the actuator piston adjusting screw from top to bottom. The actuator piston lower body is fixedly connected to the actuator piston upper body from below. The actuator piston spring presses the top of the actuator piston limit guide sleeve against the actuator piston upper body. The top of the actuator piston communicates with the actuator piston high-pressure oil passage.

[0012] Furthermore, the actuator piston adjusting screw is threadedly connected to the rocker arm body.

[0013] Furthermore, the top end of the actuator piston adjusting screw extends out of the rocker arm body, and an actuator piston adjusting nut is connected to the top end of the actuator piston adjusting screw.

[0014] Furthermore, a first cavity and a second cavity are provided on the rocker arm body corresponding to the control piston. The diameter of the second cavity is larger than that of the first cavity. The control piston is located in the first cavity. The control piston inner spring extends from the second cavity to the first cavity. A control piston outer spring is arranged in the second cavity. The inner diameter of the control piston outer spring is smaller than the diameter of the first cavity. The outer diameter of the control piston outer spring is larger than the diameter of the first cavity.

[0015] Furthermore, the second cavity communicates with the outside.

[0016] Furthermore, the oil injection space is formed by a groove provided on the one-way valve seal seat. The groove is located on the side of the one-way valve seal seat facing the control piston. The groove communicates the through hole and the brake oil inlet hole.

[0017] Furthermore, the one-way valve body is fixedly connected to the one-way valve sealing seat by threads, and the one-way valve sealing seat is fixedly connected to the rocker arm body by threads.

[0018] An application method of a hydraulic braking engine braking actuator, wherein the rocker arm body is an independent braking rocker arm, and the braking rocker arm and the exhaust rocker arm assembly are arranged side by side and connected to the same exhaust rocker arm elephant foot assembly.

[0019] An application method of a hydraulic braking engine braking actuator, wherein the rocker arm body is an exhaust rocker arm assembly, and the control unit and the execution unit are integrated in the exhaust rocker arm assembly.

[0020] Compared with the prior art, the beneficial effects of the present invention are as follows: during braking, the actuating piston can move downward to a fixed position and cannot slide, restricting the lift of the exhaust valve; during non-braking, the hydraulic oil at the execution unit flows back, the execution unit is depressurized, and the actuating piston spring pushes up the limit guide sleeve and the actuating piston, and the actuating piston is at the highest position, which will not affect the lift of the exhaust valve. At the same time, the reciprocating swing of the rocker arm will not affect the control unit; the actuating piston adjusting screw at the execution unit can adjust the initial position of the actuating piston, and the gap between the actuating piston limit guide sleeve and the head of the actuating piston adjusting screw can precisely control the extension amount of the actuating piston, so that the best braking lift of the exhaust valve can be obtained during braking and the best braking power can be obtained. Description of the Drawings

[0021] Figure 1 It is a sectional view of the position of the control piston and the one-way valve when braking is closed;

[0022] Figure 2 It is a sectional view of the position of the control piston and the one-way valve when braking is opened;

[0023] Figure 3 It is a sectional structure diagram of the one-way valve assembly;

[0024] Figure 4 It is a three-dimensional structure diagram of the one-way valve assembly;

[0025] Figure 5 It is a sectional view of the actuating piston in the initial position (brake oil has not entered the execution unit);

[0026] Figure 6 It is a sectional view of the actuating piston in the compression position in the positive work state;

[0027] Figure 7 It is a sectional view of the actuating piston pushing the valve to open in the braking state;

[0028] Figure 8 It is a schematic structural diagram of a hydraulic braking engine braking actuator;

[0029] Figure 9 A side view of the brake actuator applied to a dedicated brake rocker arm;

[0030] Figure 10 A top view of the brake actuator applied to a dedicated brake rocker arm;

[0031] Figure 11 A side view of the brake actuator applied to an integrated brake exhaust rocker arm;

[0032] Figure 12 A top view of the brake actuator applied to an integrated brake exhaust rocker arm.

[0033] Reference numerals: 1, rocker arm body; 2, check valve assembly; 3, control unit; 4, check valve spring; 5, check valve; 6, oil chamber of check valve body; 7, high-pressure oil passage of actuator piston; 8, actuator unit; 9, check valve body; 10, check valve seal seat; 11, control piston push rod; 12, brake oil inlet hole; 13, control piston; 14, outer spring of control piston; 15, inner spring of control valve piston; 16, air release port; 17, control piston gasket; 18, circlip of control piston; 19, high-pressure oil chamber of actuator piston; 20, adjusting screw of actuator piston; 21, adjusting nut of actuator piston; 22, upper body of actuator piston; 23, spring of actuator piston; 24, limit guide sleeve of actuator piston; 25, lower body of actuator piston; 26, exhaust valve; 27, exhaust valve sliding pin; 29, elephant foot assembly of exhaust rocker arm; 30, rocker shaft mounting bolt; 31, bias leaf spring of brake rocker arm; 32, positioning pin; 33, actuator piston; 34, brake cam; 35, brake rocker arm assembly; 36, rocker shaft assembly; 37, exhaust rocker arm assembly; 39, exhaust cam; 40, intake rocker arm assembly; 41, through hole; 42, groove; 43, oil flow hole. Detailed implementation manners

[0034] Refer to Figures 1 to 12 to further illustrate an embodiment of the engine brake actuator with hydraulic braking of the present invention.

[0035] In the description of the present invention, it should be noted that for orientation terms, if there are terms such as "center", "lateral (X)", "longitudinal (Y)", "vertical (Z)", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", etc., indicating the orientation and position relationship is based on the orientation or position relationship shown in the drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and should not be construed as limiting the specific protection scope of the present invention.

[0036] In addition, terms such as "first" and "second" are only used for descriptive purposes and should not be construed as indicating or implying relative importance or implicitly specifying the quantity of technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include one or more such features. In the description of the present invention, the meanings of "several" and "a number of" are two or more, unless otherwise specifically defined.

[0037] A hydraulic braking engine braking actuator includes a rocker arm body 1, and a control unit 3 and an execution unit 8 are arranged on the rocker arm body 1.

[0038] The control unit 3 includes a one-way valve assembly 2 and a control piston 13 assembly.

[0039] The one-way valve assembly 2 includes a one-way valve body 9 and a one-way valve sealing seat 10. The one-way valve sealing seat 10 and the one-way valve body 9 are fixedly connected. A through hole 41 is formed in the one-way valve sealing seat 10. A one-way valve 5 is arranged in the one-way valve body 9. A one-way valve spring 4 is arranged on the side of the one-way valve 5 facing away from the one-way valve sealing seat 10. The one-way valve 5 abuts against the through hole 41 of the one-way valve sealing seat 10. An oil flow hole 43 is formed in the one-way valve body 9, and an execution piston high-pressure oil passage 7 communicating with the oil flow hole 43 is formed in the rocker arm body 1.

[0040] The control piston 13 assembly includes a control piston 13 and a control piston push rod 11. The control piston push rod 11 and the control piston 13 are fixedly connected. The control piston push rod 11 extends into the through hole 41 of the one-way valve sealing seat 10. A control piston inner spring 15 is arranged on the side of the control piston 13 facing away from the control piston push rod 11. An oil injection space is left between the control piston 13 and the one-way valve sealing seat 10, and a braking oil inlet hole 12 communicating with the oil injection space is formed in the rocker arm body 1.

[0041] The one-way valve assembly 2 and the control piston 13 assembly are coaxial, and the axis is perpendicular to the rotation direction of the rocker arm body 1; as Figure 10 and Figure 12 shown, that is, the axes of the one-way valve assembly 2 and the control piston 13 assembly are parallel to the rocker arm shaft.

[0042] The execution unit 8 includes an execution piston adjusting screw 20, an execution piston 33, and an execution piston limiting guide sleeve 24. The execution piston 33 includes an execution piston upper body 22 and an execution piston lower body 25. The head of the execution piston adjusting screw 20 faces downward. The inner side of the execution piston limiting guide sleeve 24 is slidably connected to the execution piston adjusting screw 20. An execution piston spring 23 is arranged between the execution piston limiting guide sleeve 24 and the head of the execution piston adjusting screw 20. The execution piston upper body 22 is sleeved on the execution piston adjusting screw 20 from top to bottom. The execution piston lower body 25 is fixed to the execution piston upper body 22 from below. The execution piston spring 23 presses the top of the execution piston limiting guide sleeve 24 against the execution piston upper body 22. The top of the execution piston 33 is communicated with the execution piston high-pressure oil passage 7.

[0043] In this embodiment, the execution piston lower body 25 and the execution piston upper body 22 are fixed to each other by interference fit.

[0044] As Figure 2 shown, there is a one-way valve body oil cavity 6 in the one-way valve body 9. The one-way valve 5 is located in the one-way valve body oil cavity 6. The oil flow hole 43 communicates the one-way valve body oil cavity 6 and the execution piston high-pressure oil passage 7; As Figure 3 and Figure 4 shown, preferably, an annular groove is formed on the outer wall of the one-way valve 5. The annular groove communicates the oil flow hole 43 and the execution piston high-pressure oil passage 7, and it is not necessary to align the oil flow hole 43 with the execution piston high-pressure oil passage 7 during installation.

[0045] In Figure 1 and Figure 2 the shown state, the one-way valve assembly 2 is located above, and the control piston 13 assembly is located below. The one-way valve assembly 2 is fixedly connected to the rocker arm body 1. The control piston 13 is hermetically and slidably connected to the rocker arm body 1. The control piston push rod 11 is interference-connected to the control piston 13.

[0046] As Figure 5 、 6 and 7 shown, in the execution unit 8 of this embodiment, the execution piston 33 is hermetically and slidably connected to the rocker arm body 1. An execution piston high-pressure oil cavity 19 is formed between the execution piston upper body 22 and the rocker arm body 1. The execution piston high-pressure oil cavity 19 is communicated with the execution piston high-pressure oil passage 7.

[0047] The specific working principle is as follows:

[0048] When the brake is opened: As Figure 2As shown, the brake fluid enters the oil filling space from the brake oil inlet hole 12. Under the action of the brake fluid pressure, the control piston 13 drives the control piston push rod 11 to move downward, separating the control piston push rod 11 from the one-way valve 5. As the brake fluid gradually enters, the brake fluid will push open the one-way valve 5 and enter the oil cavity 6 of the one-way valve body through the through hole 41, pass through the oil flow hole 43 and the annular groove and enter the high-pressure oil passage 7 of the actuating piston, and enter the actuating unit 8 through the high-pressure oil passage 7 of the actuating piston; as shown in Figure 7, at the actuating unit 8, the brake fluid fills the high-pressure oil cavity 19 of the actuating piston. The brake fluid pressure acts on the upper body 22 of the actuating piston, and the resulting hydraulic thrust overcomes the elastic force of the actuating piston spring 23 through the actuating piston limit guide sleeve 24 to push the whole actuating piston 33 downward by a set height. The lower end of the actuating piston limit guide sleeve 24 abuts against the head of the screw of the actuating piston 33, that is, the actuating piston 33 extends to the maximum distance.

[0049] As Figure 7 shown, when the rocker arm body 1 rotates towards the exhaust valve 26, the actuating piston 33 pushes the exhaust valve slide pin 27 and the exhaust valve 26. Due to the action of the spring force of the exhaust valve 26, the actuating piston 33 will reversely compress the brake fluid in the high-pressure oil cavity 19 of the actuating piston, thus forming high-pressure oil. The high-pressure oil enters the oil cavity 6 formed by the one-way valve 5 through the high-pressure oil passage 7 of the actuating piston and presses the one-way valve 5 against the one-way valve sealing seat 10, thus forming a sealed high-pressure oil cavity, so that the actuating piston 33 cannot continue to slide, and the exhaust valve 26 can be opened.

[0050] When the brake is closed, no brake fluid comes out of the brake oil inlet hole 12. Under the action of the inner spring 15 of the control piston, the control piston 13 pushes the one-way valve 5 away from the one-way valve sealing seat 10 through the control piston push rod 11. As Figure 1 shown in the state, under the action of the actuating piston spring 23, the actuating piston 33 and the actuating piston limit guide sleeve 24 move upward, so that the brake fluid in the high-pressure oil cavity 19 of the actuating piston enters the brake oil inlet hole 12 through the gap formed by the separation of the one-way valve 5 from the one-way valve sealing seat 10, and the brake fluid is drained back to the oil inlet passage. A high-pressure oil cavity cannot be formed in the high-pressure oil cavity 19 of the actuating piston, so that the actuating piston 33 is at the highest point. As Figure 5 and 6 shown in the state, when the rocker arm body 1 rotates towards the exhaust valve 26, the exhaust valve 26 will not be opened.

[0051] In this embodiment, preferably, the actuating piston adjusting screw 20 is threadedly connected to the rocker arm body 1. Preferably, the top end of the actuating piston adjusting screw 20 extends out of the rocker arm body 1, and an actuating piston adjusting nut 21 is connected to the top end of the actuating piston adjusting screw 20.

[0052] An operation hole is provided at the top end of the actuating piston adjusting screw 20. This operation hole can be in the shape of a multi-prism hole to facilitate turning the actuating piston adjusting screw 20 with a tool.

[0053] According to the opening degree that the exhaust valve 26 needs to be opened, that is, to control the lift of the exhaust valve 26, the braking lift of the exhaust valve 26 is determined by the lowest position of the actuating piston 33 at the initial stage of braking and the extension amount of the actuating piston 33 during braking; in the braking test, the lowest position of the actuating piston 33 can be set by adjusting the actuating piston adjusting nut 21 and the actuating piston adjusting screw 20; for example, by moving the actuating piston adjusting screw 20 downward by a certain distance or moving the actuating piston adjusting screw 20 upward by a certain distance to obtain the optimal lowest position of the actuating piston 33, that is, the braking lift of the exhaust valve 26 at the optimal braking power.

[0054] Preferably, in this embodiment, a primary cavity and a secondary cavity are provided at the corresponding position of the rocker arm body 1 for the control piston 13. The diameter of the secondary cavity is larger than that of the primary cavity. The control piston 13 is located in the primary cavity. The control piston inner spring 15 extends from the secondary cavity into the primary cavity. A control piston outer spring 14 is provided in the secondary cavity. The inner diameter of the control piston outer spring 14 is smaller than the diameter of the primary cavity, and the outer diameter of the control piston outer spring 14 is larger than the diameter of the primary cavity.

[0055] As Figure 1 and Figure 2 shown, the primary cavity is closer to the one-way valve assembly 2 than the secondary cavity. The primary cavity is located above the secondary cavity. The secondary cavity communicates with the outside. A control piston elastic retaining ring 18 is provided on the inner wall of the secondary cavity. A control piston gasket 17 is provided above the control piston elastic retaining ring 18. A vent hole 16 is provided on the control piston gasket 17 to communicate the secondary cavity with the outside. Both the control piston inner spring 15 and the control piston outer spring 14 abut against the control piston gasket 17.

[0056] When braking is closed, there is no high-pressure oil in the oil injection space. Under the action of the braking piston inner spring, the braking piston and the braking piston push rod move upward. At this time, the top end of the braking piston outer spring abuts against the top of the secondary cavity; when braking is opened, the braking oil is filled into the oil injection space to form high-pressure oil. The braking piston slides downward against the elastic force of the braking piston inner spring. When reaching the secondary cavity, the bottom end of the braking piston will contact the braking piston outer spring, and the braking piston outer spring can be used to buffer the pressure wave during oil inlet.

[0057] Preferably, in this embodiment, the oil injection space is formed by a groove 42 opened on the one-way valve sealing seat 10. The groove 42 is located on the side of the one-way valve sealing seat 10 facing the control piston 13. The groove 42 communicates with the through hole 41 and the braking oil inlet hole 12.

[0058] As Figure 3 and 4As shown in the figure, two grooves 42 are provided on the side of the one-way valve sealing seat 10 facing the control piston 13. The two grooves 42 radially penetrate through the one-way valve sealing seat 10, and at least one end of the grooves 42 communicates with the brake oil inlet hole 12. Of course, more grooves 42 can be provided, or they can be set in other shapes, such as Figure 1 As shown in the figure, when the control piston 13 reaches the high point, the control valve is pushed open, and the brake oil flows back to the brake oil inlet hole 12 through the through hole 41 and the groove 42.

[0059] In the preferred embodiment of the present invention, the one-way valve body 9 is fixedly connected to the one-way valve sealing seat 10 by a threaded connection, and the one-way valve sealing seat 10 is fixedly connected to the rocker arm body 1 by a threaded connection.

[0060] Such as Figure 9 and 10 As shown in the figure, an application method of a hydraulic braking engine braking actuator, wherein the rocker arm body 1 is an independent braking rocker arm assembly 35, and the braking rocker arm assembly 35 and the exhaust rocker arm assembly 37 are arranged side by side and connected to the same exhaust rocker arm elephant foot assembly 29.

[0061] The braking rocker arm biasing leaf spring 31 biases the braking rocker arm against the braking cam 34, so that it is in a constant contact state with the braking cam 34. The braking lift on the braking cam 34 is transmitted to the actuator unit 8 through the braking rocker arm.

[0062] After the braking rocker arm is installed, the gap between the actuator piston 33 and the exhaust valve sliding pin 27 is set by the actuator piston adjusting screw 20 and the actuator piston adjusting nut 21.

[0063] When the braking is turned on, the actuator comes into play, and the high-pressure oil chamber 19 of the actuator piston forms a high-pressure chamber, and the actuator piston 33 pushes the exhaust valve 26 to open; when the braking is turned off, the actuator does not work, and the braking oil in the high-pressure oil chamber 19 of the actuator piston drains back from the brake oil inlet hole 12 to the oil inlet passage, and the actuator piston 33 resets to the high point.

[0064] Among them, the braking rocker arm biasing leaf spring 31 is fixed on the rocker arm shaft assembly 36 by the rocker arm shaft mounting bolt 30, and the braking rocker arm biasing leaf spring 31 is prevented from disengaging from the braking rocker arm through the positioning pin 32 on the braking rocker arm, so as to ensure that the braking rocker arm is in a constant contact state with the braking cam 34.

[0065] Such as Figure 11 and 12 As shown in the figure, an application method of a hydraulic braking engine braking actuator, wherein the rocker arm body 1 is an exhaust rocker arm assembly 37, and the control unit 3 and the actuator unit 8 are integrated in the exhaust rocker arm assembly 37.

[0066] In Figure 12 next to the exhaust rocker arm assembly 37 is the intake rocker arm assembly 40.

[0067] At this time, the exhaust rocker arm assembly 37 is the rocker arm body 1, and the braking lift on the exhaust cam 39 is transmitted to the actuator through the exhaust rocker arm assembly 37. When the braking is opened, the actuator comes into play, and the high-pressure oil chamber 19 of the actuator piston forms a high-pressure chamber, and the actuator piston 33 pushes the exhaust valve 26 to open; when the braking is closed, the actuator does not work, and the braking oil in the high-pressure oil chamber 19 of the actuator piston drains back to the oil inlet passage from the braking oil inlet hole 12, and the actuator piston 33 resets to the high point.

[0068] The actuator of the present invention is easy to be arranged on various types of engines, and the hydraulic drive mechanism occupies a small space.

[0069] The above are only the preferred embodiments of the present invention, and the protection scope of the present invention is not limited to the above embodiments. All technical solutions falling within the idea of the present invention belong to the protection scope of the present invention. It should be pointed out that for those of ordinary skill in the art, several improvements and refinements made without departing from the principle of the present invention should also be regarded as the protection scope of the present invention.

Claims

1. A hydraulic braking engine braking actuator, including a rocker arm body, characterized in that, A control unit and an execution unit are provided on the rocker arm body. The control unit includes a one-way valve assembly and a control piston assembly. One-way valve assembly, which includes a one-way valve body and a one-way valve seal seat. The one-way valve seal seat and the one-way valve body are fixedly connected. A through hole is provided on the one-way valve seal seat. A one-way valve is provided inside the one-way valve body. A one-way valve spring is provided on the side of the one-way valve facing away from the one-way valve seal seat. The one-way valve abuts against the through hole of the one-way valve seal seat. An oil flow hole is provided on the one-way valve body. An execution piston high-pressure oil passage communicating with the oil flow hole is provided on the rocker arm body. Control piston assembly, which includes a control piston and a control piston push rod. The control piston push rod and the control piston are fixedly connected. The control piston push rod extends into the through hole of the one-way valve seal seat. A control piston inner spring is provided on the side of the control piston facing away from the control piston push rod. An oil injection space is left between the control piston and the one-way valve seal seat. A brake oil inlet hole communicating with the oil injection space is provided on the rocker arm body. The one-way valve assembly and the control piston assembly are coaxial, and the axis is perpendicular to the rotation direction of the rocker arm body. Execution unit, which includes an execution piston adjusting screw, an execution piston and an execution piston limiting guide sleeve. The execution piston includes an execution piston upper body and an execution piston lower body. The head of the execution piston adjusting screw faces downward. The inner side of the execution piston limiting guide sleeve is slidably connected to the execution piston adjusting screw. An execution piston spring is provided between the execution piston limiting guide sleeve and the head of the execution piston adjusting screw. The execution piston upper body is sleeved on the execution piston adjusting screw from top to bottom. The execution piston lower body is fixedly connected to the execution piston upper body from below. The execution piston spring abuts the top of the execution piston limiting guide sleeve against the execution piston upper body. The top of the execution piston communicates with the execution piston high-pressure oil passage. A first cavity and a second cavity are provided on the rocker arm body corresponding to the control piston. The diameter of the second cavity is larger than that of the first cavity. The control piston is located in the first cavity. The control piston inner spring extends from the second cavity to the first cavity. A control piston outer spring is provided in the second cavity. The inner diameter of the control piston outer spring is smaller than the diameter of the first cavity. The outer diameter of the control piston outer spring is larger than the diameter of the first cavity. The second cavity communicates with the outside. The oil injection space is formed by a groove provided on the one-way valve seal seat. The groove is located on the side of the one-way valve seal seat facing the control piston. The groove communicates the through hole and the brake oil inlet hole. The one-way valve body is fixedly connected to the one-way valve seal seat by threading. The one-way valve seal seat is fixedly connected to the rocker arm body by threading.

2. The hydraulic braking engine braking actuator according to claim 1, characterized in that: The execution piston adjusting screw is threadedly connected to the rocker arm body.

3. The hydraulic braking engine braking actuator according to claim 2, wherein: The top end of the execution piston adjusting screw extends out of the rocker arm body. An execution piston adjusting nut is connected to the top end of the execution piston adjusting screw.

4. A method for applying a hydraulic braking engine braking actuator according to any one of claims 1-3, characterized in that: The rocker arm body is an independent brake rocker arm. The brake rocker arm and the exhaust rocker arm assembly are arranged side by side and are connected to the same exhaust rocker arm foot assembly.

5. A method for applying a hydraulic braking engine braking actuator as described in any one of claims 1 - 3, characterized in that: The rocker arm body is an exhaust rocker arm assembly. The control unit and the execution unit are integrated into the exhaust rocker arm assembly.

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