Engine brake device with time-delay active oil drain function and braking method thereof

Abstract

The application relates to the technical field of engines, in particular to an engine braking device with a delay active oil leakage function and a braking method thereof, which comprises a braking rocker arm, a shell is connected to the braking rocker arm, a high-pressure cavity is arranged in the shell, a piston is slidably connected in the high-pressure cavity, and an active oil leakage assembly is arranged on the shell and the piston. The active oil leakage assembly with the delay active oil leakage function is arranged in the engine braking device, the time relaxation effect of a driving spring in the force process is utilized, the high-pressure cavity is kept in a closed state for a predetermined time in the initial stage of engine braking, the oil pressure in the high-pressure cavity continuously increases, the valve opening stroke is increased, and the engine braking power is effectively improved; after the delay time is exceeded, the active oil leakage assembly is automatically triggered, the high-pressure cavity is communicated with an oil leakage cavity, the oil pressure in the high-pressure cavity is timely released, and impact on the braking device and related components caused by excessively high pressure is avoided.

Description

Technical Field

[0001] This invention relates to the field of engine technology, specifically to an engine braking device and braking method with a delayed active oil drain function. Background Technology

[0002] Engine braking systems, as a technology that utilizes the engine's own resistance to achieve auxiliary braking of vehicles, have been widely used in medium and heavy-duty vehicles. Existing engine braking systems typically achieve a braking effect by controlling valve opening during engine braking, causing significant pumping losses in the cylinder during compression and exhaust. In this type of engine braking system, a high-pressure chamber is often incorporated within the brake rocker arm or related actuator, and the hydraulic pressure of lubricating oil is used to open the valves to obtain the required braking power.

[0003] However, in practical applications, existing engine braking systems typically face the following problems: On the one hand, to improve braking performance, it is necessary to increase the hydraulic pressure in the high-pressure chamber as much as possible during the initial braking phase to increase the valve opening stroke; on the other hand, when the pressure in the high-pressure chamber continues to rise, it easily places higher demands on the structural strength and reliability of the braking system, and may even lead to component impact, fatigue, or damage. Therefore, existing technologies often employ passive pressure relief methods such as pressure relief valves or overflow valves, which provide pressure relief protection after the pressure in the high-pressure chamber reaches a preset threshold. However, these methods usually release pressure as soon as the threshold is reached, making it difficult to simultaneously improve braking performance during the initial braking phase.

[0004] Furthermore, some existing technologies control the timing of oil release by adding control mechanisms or employing complex hydraulic control logic. However, these solutions are structurally complex, costly to control, and their stability and reliability under high-speed engine conditions still need improvement. Therefore, achieving a reasonable balance between maintaining high pressure during the initial braking phase and subsequent safe oil release without significantly increasing system complexity remains a pressing technical problem in the field of engine braking systems. Summary of the Invention

[0005] The purpose of this invention is to provide an engine braking device and braking method with a delayed active oil drain function, aiming to solve the technical problems mentioned in the background art.

[0006] To achieve the above objectives, the present invention provides the following technical solution:

[0007] An engine braking device with a delayed active oil drain function includes a brake rocker arm, a housing connected to the brake rocker arm, a high-pressure chamber inside the housing, a piston slidably connected inside the high-pressure chamber, an active oil drain assembly jointly provided on the housing and the piston, the active oil drain assembly including an oil drain chamber opened in the housing, an oil drain spring and a bidirectional moving member provided in the oil drain chamber, an end cap provided at one end of the bidirectional moving member, and the active oil drain assembly further including a first limiting surface for limiting the axial movement stroke of the bidirectional moving member.

[0008] Furthermore, during engine braking, the bidirectional moving part and the end cap at one end maintain a non-connected state between the high-pressure chamber and the oil drain chamber in the initial stage of braking, and after a predetermined response delay, overcomes the elastic force of the oil drain spring and undergoes axial displacement under the limitation of the first limiting surface, so that the high-pressure chamber and the oil drain chamber are connected, thereby realizing delayed active oil drain.

[0009] Furthermore, a first connecting member is provided in the oil drain chamber, and the two ends of the oil drain spring abut against the first connecting member and the end cap respectively. The driving spring is sleeved on the outer periphery of the bidirectional moving member, and the two ends of the driving spring abut against the end cap and the piston respectively.

[0010] Furthermore, the active oil drain assembly also includes a first spring mounting groove formed on the piston surface, the drive spring being disposed in the first spring mounting groove, and one end of the drive spring abutting against the bottom of the first spring mounting groove.

[0011] Furthermore, the active oil drain assembly also includes a guide groove formed on the piston surface, and a guide rod is provided at the end of the bidirectional moving member away from the end cap, and the guide rod is axially inserted into the guide groove.

[0012] Furthermore, the first limiting surface is disposed within the oil drain cavity and located on the axial movement path of the end cover, thereby limiting the maximum axial displacement of the bidirectional moving component and the end cover toward the side closer to the oil drain cavity.

[0013] Furthermore, the brake rocker arm has an oil hole and an annular oil groove communicating with the oil hole inside, and an oil inlet assembly is provided on the housing. The annular oil groove is used to provide lubricating oil to the oil inlet assembly.

[0014] Furthermore, a pressure relief assembly is provided on the housing, which is used to relieve pressure in the high-pressure chamber.

[0015] Furthermore, a locking nut is provided on the brake rocker arm. The locking nut is used to fix the housing on the brake rocker arm, and after the housing is fixedly installed, the oil inlet assembly is connected to the annular oil groove.

[0016] Furthermore, a braking method for an engine braking device with a delayed active oil discharge function, the method comprising:

[0017] S1, Under engine braking conditions, the brake rocker arm drives the piston to move into the high-pressure chamber under the drive of the engine, so that the lubricating oil in the high-pressure chamber is compressed to build up the high-pressure oil pressure required for braking, and pushes the valve bridge to open the valve.

[0018] S2, within the time t after the piston begins to compress the high-pressure chamber, the piston displacement is transmitted to the bidirectional moving part through the drive spring. Due to the elastic deformation of the drive spring and the delay effect of its force transmission, the bidirectional moving part and the end cover do not undergo axial displacement that would connect the high-pressure chamber and the oil drain chamber within the time t. Thus, the high-pressure chamber and the oil drain chamber remain in a non-connected state within the time t, so as to maintain the high-pressure oil pressure in the high-pressure chamber and continue to increase the valve opening stroke.

[0019] S3, when the piston continues to move and exceeds the time t, the elastic deformation of the drive spring reaches the predetermined state and overcomes the elastic force of the drain spring, thereby pushing the bidirectional moving part and the end cover to undergo axial displacement and cross the first limiting surface, so that the high pressure chamber and the drain chamber are connected.

[0020] S4 After the high-pressure chamber and the drain chamber are connected, the lubricating oil in the high-pressure chamber is actively released through the drain chamber to reduce the oil pressure in the high-pressure chamber. This ensures the engine braking effect while preventing the pressure in the high-pressure chamber from continuously increasing and causing damage to the engine braking device.

[0021] The present invention provides an engine braking device and braking method with a delayed active oil drain function, which has the following beneficial effects:

[0022] This invention incorporates an active oil drain component with a delayed active oil drain function into the engine braking system. Utilizing the time relaxation effect of the drive spring during the force application process, the high-pressure chamber remains sealed for a predetermined time during the initial stage of engine braking, thereby continuously increasing the oil pressure within the high-pressure chamber. This increases the valve opening stroke and effectively enhances engine braking power. After the delay period, the active oil drain component automatically triggers, connecting the high-pressure chamber and the drain chamber, promptly releasing the oil pressure within the high-pressure chamber and preventing impact and damage to the braking system and related components due to excessive pressure. This invention achieves a balance between improved braking performance and structural safety without requiring additional control mechanisms or complex control logic. It features a simple structure, high reliability, and is easily applicable to existing engine platforms. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of an engine braking device with a delayed active oil drain function.

[0024] Figure 2 This is a front sectional view of an engine braking device with delayed active oil discharge function under working compression state.

[0025] Figure 3 This is a front sectional view of the housing of an engine braking device with a delayed active oil drain function.

[0026] Figure 4 This is a front sectional view of a piston in an engine braking device with a delayed active oil drain function.

[0027] Figure 5 This is a front sectional view of the end cover, bidirectional moving parts, and guide rod of an engine braking device with delayed active oil drain function.

[0028] Figure 6 This is a front sectional view of an engine braking device with delayed active oil drain function in its non-operating state.

[0029] Figure 7 This is a side sectional view of an engine braking device with a delayed active oil drain function in its initial working state.

[0030] Figure 8 This is a schematic diagram of the brake rocker arm and housing in an engine braking device with a delayed active oil drain function.

[0031] Figure 9 This is a schematic diagram of a braking system that includes an engine braking device with a delayed active oil discharge function.

[0032] Figure 10 This is a partial cross-sectional view of an active oil draining assembly in another embodiment of the present invention, which uses an oil draining control steel ball to replace a bidirectional moving part.

[0033] In the diagram: 1. Brake rocker arm; 2. Housing; 3. Active oil drain assembly; 31. First connecting piece; 32. Oil drain spring; 33. End cap; 34. Oil drain chamber; 35. Bidirectional moving part; 36. Guide rod; 37. Guide groove; 38. First spring mounting slot; 39. First limiting surface; 310. Drive spring; 311. Oil drain control ball; 4. Oil inlet assembly; 41. Oil inlet chamber plug; 42. Oil inlet chamber; 43. Oil inlet hole; 44. Second limiting surface; 5. Oil inlet steel ball; 46. Oil inlet chamber spring; 47. Second connecting piece; 5. Pressure relief assembly; 51. Third connecting piece; 52. Pressure relief chamber spring; 53. Pressure relief steel ball; 54. Third limiting surface; 55. Pressure relief chamber; 6. Annular oil groove; 7. Locking nut; 8. Piston; 9. Oil hole; 10. High pressure chamber; 11. Fixing plate; 12. High pressure chamber spring; 13. Valve bridge; 14. Valve spring; 15. Valve stem A; 16. Valve stem B; 17. Cylinder. Detailed Implementation

[0034] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0035] The specific implementation of the present invention will be described in detail below with reference to specific embodiments.

[0036] like Figures 1-9 As shown, an embodiment of the present invention provides an engine braking device with a delayed active oil drain function, including a braking rocker arm 1. The engine braking device is installed on the cylinder 17 of the engine and is used in conjunction with the valve mechanism of the engine as an actuator in the engine braking system. The overall structure, installation method and connection relationship with the valve mechanism of the engine braking system are conventional technologies known in the art. The improvement of the present invention does not lie in the engine braking system itself, but in the active oil drain structure and its working mechanism inside the braking device.

[0037] A housing 2 is connected to the brake rocker arm 1. A locking bolt 7 is provided on the top of the housing 2 to ensure stable installation between the housing 2 and the brake rocker arm 1, thereby guaranteeing the reliability of the relative positions of the components during engine braking. A fixing plate 11 is provided at the bottom of the housing 2 to limit the movement between the housing 2 and the piston 8. A high-pressure chamber 10 is provided inside the housing 2, and the piston 8 is slidably connected inside the high-pressure chamber 10. During engine braking, the reciprocating motion of the piston 8 applies pressure to the lubricating oil in the high-pressure chamber 10, thereby creating a high-pressure oil environment for valve braking. An active oil drain assembly 3 is provided on both the housing 2 and the piston 8. This active oil drain assembly 3 is used to adjust the oil pressure in the high-pressure chamber 10 when predetermined conditions are met, and is a key component for realizing the delayed active oil drain function.

[0038] The active oil drain assembly 3 includes an oil drain chamber 34 formed within the housing 2. The oil drain chamber 34 is used to receive and drain lubricating oil from the high-pressure chamber 10 when it is in communication with the high-pressure chamber 10. An oil drain spring 32 and a bidirectional moving member 35 are disposed within the oil drain chamber 34. The bidirectional moving member 35 is preferably a bidirectional moving rod. The oil drain spring 32 applies a restoring force to the bidirectional moving member 35 to ensure it maintains its initial position when not draining oil. One end of the bidirectional moving member 35 is provided with an end cap 33, which moves in conjunction with the bidirectional moving member 35 and forms a cooperative relationship with the oil drain chamber 34 and the high-pressure chamber 10. The active oil drain assembly 3 also includes a first limiting surface 39 for limiting the axial movement stroke of the bidirectional moving member 35. The first limiting surface 39 is disposed within the oil drain chamber 34 and located on the axial movement path of the end cap 33, limiting the maximum axial displacement of the bidirectional moving member 35 and the end cap 33 towards the side closer to the oil drain chamber 34, thereby preventing overtravel of the bidirectional moving member 35 and ensuring the stability and reliability of the active oil drain process.

[0039] During engine braking, the bidirectional moving part 35 and its end cap 33 keep the high-pressure chamber 10 and the oil drain chamber 34 in a non-connected state in the initial stage of braking. At this time, the lubricating oil in the high-pressure chamber 10 is in a closed and compressed state to continuously provide the braking force required by the valve mechanism. After a predetermined response delay, it overcomes the elastic force of the oil drain spring 32 and undergoes axial displacement under the limitation of the first limiting surface 39, so that the high-pressure chamber 10 and the oil drain chamber 34 are connected, thereby realizing delayed active oil drain, so that the oil pressure in the high-pressure chamber 10 is released after the expected braking effect is achieved.

[0040] The oil drain chamber 34 is provided with a first connector 31, which is used to provide stable installation and force support for the oil drain spring 32. The two ends of the oil drain spring 32 abut against the first connector 31 and the end cap 33 respectively. The drive spring 310 is sleeved on the outer periphery of the bidirectional moving member 35. The drive spring 310 is used to transmit the movement of the piston 8 to the bidirectional moving member 35 with a delay, and the two ends of the drive spring 310 abut against the end cap 33 and the piston 8 respectively.

[0041] The active oil drain assembly 3 also includes a first spring mounting groove 38 formed on the surface of the piston 8. The first spring mounting groove 38 is used to position and limit the drive spring 310. The drive spring 310 is set in the first spring mounting groove 38, and one end of the drive spring 310 abuts against the bottom of the first spring mounting groove 38 to ensure that the drive spring 310 is subjected to uniform force and works stably during the movement of the piston 8.

[0042] The active oil drain assembly 3 also includes a guide groove 37 formed on the surface of the piston 8. The guide groove 37 is used to constrain the movement direction of the bidirectional moving part 35. A guide rod 36 is provided at the end of the bidirectional moving part 35 away from the end cover 33, and the guide rod 36 is axially inserted in the guide groove 37, thereby ensuring that the bidirectional moving part 35 moves only axially during operation, avoiding deviation or jamming, and further improving the reliability of the delayed active oil drain process.

[0043] The piston 8 is configured to drive the bidirectional moving member 35 to move axially against the elastic force of the oil drain spring 32 during the movement, so as to control the oil draining action of the active oil draining assembly 3.

[0044] In one embodiment of the present invention, such as Figure 9 As shown, the engine braking system includes an engine body, a valve mechanism, and an engine braking device mounted on the valve mechanism. The brake rocker arm 1 is mounted on the cylinder 17 via the engine's original rocker arm shaft or support structure and cooperates with the valve bridge 13. The valve bridge 13 connects the valve stem A15 and the valve stem B16, and the valve stem A15 and the valve stem B16 are respectively connected to the corresponding valve and valve spring 14. The housing 2 is fixedly mounted on the brake rocker arm 1 by a locking nut 7, and a stable assembly relationship is formed between the housing 2 and the brake rocker arm 1. The overall structural form and installation method of the above-mentioned engine braking system are all prior art and are not considered as inventive points in this invention.

[0045] In engine braking mode, the engine switches to braking mode, causing the brake rocker arm 1 to move under the action of the cam mechanism or corresponding drive mechanism. The brake rocker arm 1 drives the housing 2 mounted on it and the piston 8 inside the housing 2 to move into the high-pressure chamber 10, thereby compressing the lubricating oil in the high-pressure chamber 10. Under the action of the increased oil pressure in the high-pressure chamber 10, the piston 8 applies a force to the valve bridge 13 through the housing 2. The valve bridge 13 overcomes the elastic force of the valve spring 14 and moves downward, causing the valve to open. Thus, the pumping loss generated during the valve opening process is used to achieve engine braking. The basic working process of this engine braking is also in the prior art.

[0046] During the aforementioned engine braking process, the present invention provides an active oil drain assembly 3 on the housing 2 and the piston 8, which enables a delayed connection between the high-pressure chamber 10 and the oil drain chamber 34. In the initial stage of braking, when the piston 8 begins to compress the high-pressure chamber 10, the displacement of the piston 8 is transmitted to the bidirectional moving member 35 through the drive spring 310. Due to the elastic deformation of the drive spring 310 and the delayed effect of its force transmission, the bidirectional moving member 35 and its end cap 33 do not undergo axial displacement sufficient to connect the high-pressure chamber 10 and the oil drain chamber 34 for a period of time. Thus, the high-pressure chamber 10 remains sealed during this time, and the oil pressure in the high-pressure chamber 10 continues to rise, allowing the valve to obtain a larger opening stroke and improving the engine braking effect.

[0047] As the piston 8 continues to move, when the elastic deformation of the drive spring 310 reaches the predetermined state and overcomes the elastic force of the drain spring 32, the bidirectional moving part 35 and the end cover 33 undergo axial displacement under the limitation of the first limiting surface 39, so that the high pressure chamber 10 is connected to the drain chamber 34. The lubricating oil in the high pressure chamber 10 is actively released through the drain chamber 34, thereby reducing the oil pressure in the high pressure chamber 10 and preventing the pressure in the high pressure chamber 10 from continuously increasing and causing damage to the engine braking device and related components.

[0048] In one embodiment of the present invention, the delay is related not only to the elastic deformation stroke of the drive spring 310, but also to the time relaxation effect of the drive spring 310 during the force application process. Specifically, when the piston 8 begins to move into the high-pressure chamber 10 and applies a load to the drive spring 310, the drive spring 310 will not immediately transmit the load completely to the bidirectional moving member 35 in a short period of time. Instead, due to the elastic recovery characteristics of the material itself and the internal stress release process, it exhibits a relaxation behavior in which the force transmission gradually builds up over time, thus forming a natural response delay within the time t after the piston 8 begins to move. During this time t, the bidirectional moving member 35 and the end cap 33 remain in their initial positions, and the high-pressure chamber 10 and the oil drain chamber 34 remain in a non-connected state. When the relaxation process of the drive spring 310 is completed and a stable force transmission state is gradually established, its output force overcomes the elastic force of the oil drain spring 32, pushing the bidirectional moving member 35 and the end cap 33 to undergo axial displacement, thereby realizing the connection between the high-pressure chamber 10 and the oil drain chamber 34. Therefore, by utilizing the time relaxation effect of the drive spring 310, the present invention achieves the function of delaying the maintenance of pressure in the high-pressure chamber 10 and then actively draining oil without adding an additional control structure.

[0049] In another embodiment, the active oil drain assembly can also employ a simplified structure. For example... Figure 10 As shown, the bidirectional moving component 35 in the original active oil drain assembly is omitted, and the related switching structure is replaced with an oil drain control ball 311. The oil drain control ball 311 moves along a set direction under the action of oil pressure and / or the action of an elastic element to open or close the active oil drain channel, thereby achieving the delayed active oil drain function. Compared with the structure using bidirectional moving components 35 and 37, this embodiment has a simpler structure, fewer parts, which helps reduce processing and assembly difficulty and improve operational reliability.

[0050] Through the above structure and working process, the present invention has at least the following beneficial effects:

[0051] 1. During the initial stage of engine braking, delayed active oil discharge maintains and continues to increase the oil pressure in the high-pressure chamber for a certain period of time, thereby increasing the valve opening stroke and improving engine braking power.

[0052] 2. After the predetermined delay is reached, the pressure in the high-pressure chamber is reduced in time by actively draining oil, which effectively avoids structural impact and reliability problems caused by excessive pressure in the braking device;

[0053] 3. The delay effect is naturally formed by the elastic deformation and force transmission characteristics of the drive spring, without the need for additional control mechanisms. It has a simple structure, high reliability, and is easy to promote and apply on existing engine platforms.

[0054] In this embodiment, the brake rocker arm 1 has an oil hole 9 and an annular oil groove 6 communicating with the oil hole 9 inside. The housing 2 is provided with an oil inlet assembly 4, and the annular oil groove 6 is used to provide lubricating oil to the oil inlet assembly 4. The brake rocker arm 1 is provided with a locking nut 7, which is used to fix the housing 2 on the brake rocker arm 1, and after the housing 2 is fixedly installed, the oil inlet assembly 4 communicates with the annular oil groove 6.

[0055] 4. In each engine braking cycle, after the piston 8 contacts the valve bridge 13 and the valve bridge 13 reaches the predetermined downward position, the active oil drain assembly 3 connects the high-pressure chamber 10 with the oil drain chamber 34, allowing the lubricating oil in the high-pressure chamber 10 to be released through the oil drain chamber 34. The oil pressure in the high-pressure chamber 10 is reduced in time, and the piston 8 can return to its initial position under the reset action of the high-pressure chamber spring 12, the valve bridge 13, and the valve spring 14. This avoids the piston 8 continuously squeezing the valve bridge 13 in the next intake or compression stroke, and prevents the valve bridge 13 from abnormally opening the valves corresponding to valve stem A15 and / or valve stem B16. This ensures that the cylinder 17 effectively compresses the intake gas in the next compression stroke, so that the gas discharged in the subsequent braking exhaust stage has a higher temperature, pressure, and energy, thereby improving the engine's braking power.

[0056] The oil hole 9 and the annular oil groove 6 form a lubricating oil supply channel inside the brake rocker arm 1. When the engine is running, lubricating oil enters the annular oil groove 6 through the oil hole 9 and is distributed circumferentially inside the brake rocker arm 1 along the annular oil groove 6, thereby providing a stable source of lubricating oil for the housing 2 mounted on the brake rocker arm 1. By connecting the annular oil groove 6 to the oil inlet assembly 4, lubricating oil can enter the interior of the housing 2 for supplying oil and lubricating the high-pressure chamber 10 and related moving parts, so as to ensure the normal operation of the engine braking device during operation.

[0057] The oil inlet assembly 4 is mounted on the housing 2. The oil inlet assembly 4 includes an oil inlet chamber 42, an oil inlet hole 43, an oil inlet steel ball 45, and an oil inlet chamber spring 46. The oil inlet chamber 42 is formed inside the housing 2 and is correspondingly arranged with the annular oil groove 6. The oil inlet steel ball 45 and the oil inlet chamber spring 46 together form a one-way oil inlet structure. When the lubricating oil pressure in the annular oil groove 6 is greater than the pressure in the oil inlet chamber 42, the lubricating oil pushes the oil inlet steel ball 45 to overcome the elastic force of the oil inlet chamber spring 46 and enter the oil inlet chamber 42, thereby replenishing the high-pressure chamber 10 with lubricating oil. When the pressure in the high-pressure chamber 10 increases, the oil inlet steel ball 45 returns to its original position under the action of the oil inlet chamber spring 46 and blocks the oil inlet hole 43 to prevent the lubricating oil in the high-pressure chamber 10 from flowing out in reverse.

[0058] The locking nut 7 is used to reliably fix the housing 2 onto the brake rocker arm 1, and after assembly, ensure that the oil inlet component 4 on the housing 2 and the annular oil groove 6 inside the brake rocker arm 1 form a corresponding communication relationship, thereby realizing the automatic supply of lubricating oil from the brake rocker arm 1 to the inside of the housing 2 without adding an additional oil circuit structure.

[0059] In this embodiment, a pressure relief assembly 5 is provided on the housing 2, which is used to relieve pressure in the high-pressure chamber 10.

[0060] The pressure relief assembly 5 is installed on the housing 2 and communicates with the high-pressure chamber 10. It is used to relieve pressure in the high-pressure chamber 10 when the oil pressure in the high-pressure chamber 10 rises abnormally, thereby preventing excessive pressure in the high-pressure chamber 10 from causing structural damage to the engine braking device. By installing the pressure relief assembly 5, the oil pressure in the high-pressure chamber 10 can be passively released under abnormal operating conditions, thereby improving the overall safety and reliability of the engine braking device.

[0061] In this embodiment, the pressure relief assembly 5 includes a pressure relief chamber 55, a pressure relief steel ball 53, and a pressure relief chamber spring 52. The pressure relief chamber 55 is formed inside the housing 2 and communicates with the high-pressure chamber 10. The pressure relief steel ball 53 and the pressure relief chamber spring 52 cooperate to form a one-way pressure relief structure. When the oil pressure in the high-pressure chamber 10 exceeds a predetermined threshold, the oil in the high-pressure chamber 10 pushes the pressure relief steel ball 53 to overcome the elastic force of the pressure relief chamber spring 52 and open the pressure relief passage, so that the oil in the high-pressure chamber 10 is released through the pressure relief chamber 55, thereby reducing the oil pressure in the high-pressure chamber 10. When the oil pressure in the high-pressure chamber 10 returns to the normal range, the pressure relief steel ball 53 returns to its original position under the action of the pressure relief chamber spring 52 and blocks the pressure relief passage to prevent the oil from continuously leaking out.

[0062] In this embodiment, the pressure relief component 5 serves as a safety protection structure and is functionally independent of the active oil drain component 3. The active oil drain component 3 is used to actively drain oil from the high-pressure chamber 10 according to a predetermined delay logic during engine braking, while the pressure relief component 5 only works passively under abnormal pressure conditions to prevent excessive pressure in the high-pressure chamber 10.

[0063] like Figures 1-9 As shown, in one embodiment of the present invention, a braking method for an engine braking device with a delayed active oil discharge function includes:

[0064] S1, Under engine braking conditions, the brake rocker arm 1 drives the piston 8 to move into the high-pressure chamber 10 under the drive of the engine, so that the lubricating oil in the high-pressure chamber 10 is compressed to establish the high-pressure oil pressure required for braking, and pushes the valve bridge 13 to open the valve.

[0065] S2, within the time t after the piston 8 begins to compress the high-pressure chamber 10, the displacement of the piston 8 is transmitted to the bidirectional moving part 35 through the drive spring 310. Due to the elastic deformation of the drive spring 310 and the delay effect of its force transmission, the bidirectional moving part 35 and the end cover 33 do not undergo axial displacement that would connect the high-pressure chamber 10 and the oil drain chamber 34 within the time t. Thus, the high-pressure chamber 10 and the oil drain chamber 34 remain in a non-connected state within the time t, so as to maintain the high-pressure oil pressure in the high-pressure chamber 10 and continue to increase the valve opening stroke.

[0066] S3, when the piston 8 continues to move and exceeds time t, the elastic deformation of the drive spring 310 reaches the predetermined state and overcomes the elastic force of the drain spring 32, thereby pushing the bidirectional moving part 35 and the end cover 33 to undergo axial displacement and cross the first limiting surface 39, so that the high pressure chamber 10 and the drain chamber 34 are connected.

[0067] S4 After the high-pressure chamber 10 is connected to the oil drain chamber 34, the lubricating oil in the high-pressure chamber 10 is actively released through the oil drain chamber 34 to reduce the oil pressure in the high-pressure chamber 10, thereby ensuring the engine braking effect while avoiding damage to the engine braking device caused by the continuous increase of pressure in the high-pressure chamber 10.

[0068] Specifically, under engine braking conditions, the brake rocker arm 1 drives the housing 2 to move towards the valve bridge 13. After the piston 8 contacts the valve bridge 13, the piston 8 moves relative to the housing 2 and acts on the lubricating oil in the high-pressure chamber 10. In the initial stage of this movement, the active oil drain assembly 3 keeps the high-pressure chamber 10 and the oil drain chamber 34 in a non-connected state. When the piston 8 contacts the valve bridge 13 and pushes the valve bridge 13 down to the predetermined lowest position against the elastic force of the valve spring 14, the valve bridge 13 begins to move upward under the restoring action of the valve spring 14. At this time, the delayed force transmission of the drive spring 310 to the bidirectional moving member 35 reaches the predetermined state. The bidirectional moving member 35 and the end cap 33 overcome the elastic force of the oil drain spring 32 and cross the first limiting surface 39, so that the high-pressure chamber 10 and the oil drain chamber 34 are connected. After the lubricating oil in the high-pressure chamber 10 is released through the drain chamber 34, the hydraulic support of the high-pressure chamber 10 on the piston 8 decreases, allowing the piston 8 to return to its original position under the action of the high-pressure chamber spring 12 and the valve mechanism's reset force. The valve bridge 13 then drives the valves corresponding to valve stems A15 and B16 to close. This drain sequence ensures that the predetermined valve opening and exhaust release are completed in the current braking cycle, while preventing the piston 8 from remaining in the extended position and affecting the next compression cycle. This improves the amount of gas compression energy released and the engine braking power in each braking cycle.

[0069] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. An engine braking device with a delayed active oil drain function, comprising a brake rocker arm (1), characterized in that, The brake rocker arm (1) is connected to a housing (2), and a high-pressure chamber (10) is provided inside the housing (2). A piston (8) is slidably connected inside the high-pressure chamber (10). An active oil drain assembly (3) is provided on both the housing (2) and the piston (8). The active oil drain assembly (3) includes an oil drain chamber (34) opened inside the housing (2). An oil drain spring (32) and a bidirectional moving member (35) are provided inside the oil drain chamber (34). An end cap (33) is provided at one end of the bidirectional moving member (35). The active oil drain assembly (3) also includes a first limiting surface (39) for limiting the axial movement stroke of the bidirectional moving member (35).

2. An engine braking device with delayed active oil discharge function according to claim 1, characterized in that, During engine braking, the bidirectional moving part (35) and its end cap (33) maintain the high pressure chamber (10) and the oil drain chamber (34) in a non-connected state in the initial stage of braking. After a predetermined response delay, it overcomes the elastic force of the oil drain spring (32) and undergoes axial displacement under the limitation of the first limiting surface (39) so that the high pressure chamber (10) and the oil drain chamber (34) are connected, thereby realizing delayed active oil drain.

3. An engine braking device with delayed active oil discharge function according to claim 1, characterized in that, The oil drain chamber (34) is provided with a first connector (31), and the two ends of the oil drain spring (32) abut against the first connector (31) and the end cap (33) respectively. The drive spring (310) is sleeved on the outer periphery of the bidirectional moving part (35), and the two ends of the drive spring (310) abut against the end cap (33) and the piston (8) respectively.

4. An engine braking device with delayed active oil discharge function according to claim 3, characterized in that, The active oil drain assembly (3) further includes a first spring mounting groove (38) formed on the surface of the piston (8), the drive spring (310) is disposed in the first spring mounting groove (38), and one end of the drive spring (310) abuts against the bottom of the first spring mounting groove (38).

5. An engine braking device with delayed active oil discharge function according to claim 1, characterized in that, The active oil drain assembly (3) also includes a guide groove (37) formed on the surface of the piston (8). A guide rod (36) is provided at one end of the bidirectional moving part (35) away from the end cap (33), and the guide rod (36) is axially inserted into the guide groove (37).

6. An engine braking device with delayed active oil discharge function according to claim 1, characterized in that, The first limiting surface (39) is disposed in the oil drain cavity (34) and located on the axial movement path of the end cover (33), and is used to limit the maximum axial displacement of the bidirectional moving part (35) and the end cover (33) towards the side closer to the oil drain cavity (34).

7. An engine braking device with delayed active oil drain function according to claim 1, characterized in that, The brake rocker arm (1) has an oil hole (9) and an annular oil groove (6) communicating with the oil hole (9) inside. The housing (2) is provided with an oil inlet assembly (4). The annular oil groove (6) is used to provide lubricating oil to the oil inlet assembly (4).

8. An engine braking device with delayed active oil discharge function according to claim 1, characterized in that, The housing (2) is provided with a pressure relief assembly (5), which is used to relieve pressure in the high-pressure chamber (10).

9. An engine braking device with delayed active oil discharge function according to any one of claims 7-8, characterized in that, A locking nut (7) is provided on the brake rocker arm (1). The locking nut (7) is used to fix the housing (2) on the brake rocker arm (1) and after the housing (2) is fixedly installed, the oil inlet assembly (4) is connected to the annular oil groove (6).

10. A braking method for an engine braking device with a delayed active oil discharge function, characterized in that, The method includes: S1, Under engine braking conditions, the brake rocker arm (1) drives the piston (8) to move into the high-pressure chamber (10) under the drive of the engine, so that the lubricating oil in the high-pressure chamber (10) is compressed to establish the high-pressure oil pressure required for braking, and pushes the valve bridge (13) to open the valve. S2, within the time t after the piston (8) begins to compress the high-pressure chamber (10), the displacement of the piston (8) is transmitted to the bidirectional moving part (35) through the drive spring (310). Due to the elastic deformation of the drive spring (310) and the delay effect of its force transmission, the bidirectional moving part (35) and the end cover (33) do not undergo axial displacement that connects the high-pressure chamber (10) and the drain chamber (34) within the time t. Thus, the high-pressure chamber (10) and the drain chamber (34) remain in a non-connected state within the time t, so as to maintain the high-pressure oil pressure in the high-pressure chamber (10) and continue to increase the valve opening stroke. S3, when the piston (8) continues to move and exceeds the time t, the elastic deformation of the drive spring (310) reaches the predetermined state and overcomes the elastic force of the drain spring (32), thereby pushing the bidirectional moving part (35) and the end cover (33) to undergo axial displacement and cross the first limiting surface (39), so that the high pressure chamber (10) and the drain chamber (34) are connected. S4 After the high pressure chamber (10) and the oil drain chamber (34) are connected, the lubricating oil in the high pressure chamber (10) is actively released through the oil drain chamber (34) to reduce the oil pressure in the high pressure chamber (10), thereby ensuring the engine braking effect while avoiding the continuous increase of pressure in the high pressure chamber (10) from damaging the engine braking device.

Images