Reset type rocker arm braking device and vehicle

Abstract

The utility model relates to the technical field of engine braking, in particular to a reset type rocker arm braking device and a vehicle. The reset type rocker arm braking device comprises a rocker arm, and the second end of the rocker arm is provided with an exhaust cavity, a braking cavity, a one-way valve cavity and a reset cavity; the rocker arm shaft is provided with a first shaft oil duct and a second shaft oil duct. The rocker arm is provided with a first communicating oil duct, a second communicating oil duct, a third communicating oil duct, a fourth communicating oil duct and a fifth communicating oil duct. A blocking piece is arranged in the exhaust cavity, and a communicating channel is arranged on the blocking piece to divide the exhaust cavity into a first sub-cavity and a second sub-cavity which are communicated with each other; the first communicating oil duct is communicated between the first shaft oil duct and the one-way valve cavity, the second communicating oil duct is communicated between the second shaft oil duct and the reset cavity, the third communicating oil duct is communicated between the reset cavity and the second sub-cavity, the fourth communicating oil duct is communicated between the first sub-cavity and the brake cavity, and the fifth communicating oil duct is communicated between the one-way valve cavity and the brake cavity.

Description

Technical Field

[0001] The utility model relates to the technical field of engine braking, in particular to a reset rocker arm braking device and a vehicle. Background Art

[0002] During the driving of a vehicle, when passing through a downhill section, stepping on the brake for a long time will cause the brake to overheat, which will affect the service life of the brake over time. Rocker arm braking is a technology that realizes in-cylinder braking by opening the exhaust valve earlier or delaying it. The existing rocker arm braking device generally realizes the opening and closing of the braking function through a hydraulic tappet structure. The oil inlet rate of the braking chamber of the rocker arm braking device in the prior art is low, which will lead to unstable braking performance of the engine at high speeds and too high in-cylinder pressure, reducing the service life of the braking device. Summary of the Utility Model

[0003] The purpose of the utility model is to provide a reset rocker arm braking device and a vehicle, so as to solve to a certain extent the technical problem in the prior art that the oil inlet rate of the braking chamber of the rocker arm braking device is low, which will lead to unstable braking performance of the engine at high speeds and too high in-cylinder pressure, reducing the service life of the braking device.

[0004] The utility model provides a reset rocker arm braking device, comprising: a cam, along the circumferential direction of the cam, braking protrusions and exhaust protrusions are arranged on the cam at intervals, and the height of the braking protrusions is less than that of the exhaust protrusions; a rocker arm assembly, including a rocker arm, a rocker arm shaft and a roller; the rocker arm is rotatably connected to a cylinder block through the rocker arm shaft, the roller is rotatably arranged at the first end of the rocker arm, and an exhaust cavity, a braking cavity, a one-way valve cavity and a reset cavity are arranged at the second end of the rocker arm; a first shaft oil passage and a second shaft oil passage are arranged on the rocker arm shaft, and a first communication oil passage, a second communication oil passage, a third communication oil passage, a fourth communication oil passage and a fifth communication oil passage are arranged on the rocker arm; a stopper is arranged in the exhaust cavity, and a communication channel is arranged on the stopper to divide the exhaust cavity into a first sub-cavity and a second sub-cavity including communication; an exhaust valve assembly is arranged in the first sub-cavity, and the exhaust valve assembly is used for switching the communication channel between the first sub-cavity and the second sub-cavity; an exhaust assembly is arranged in the second sub-cavity, and the exhaust assembly is used for contacting an exhaust valve bridge, and a first set gap is arranged between the exhaust assembly and the stopper; a braking assembly is arranged in the braking cavity, and the braking assembly is used for contacting an exhaust valve pin; a one-way valve assembly is arranged in the one-way valve cavity, a reset assembly is arranged in the reset cavity, and an oil drain port is arranged on the reset cavity; the first communication oil passage communicates between the first shaft oil passage and the one-way valve cavity, the second communication oil passage communicates between the second shaft oil passage and the reset cavity, the third communication oil passage communicates between the reset cavity and the second sub-cavity, the fourth communication oil passage communicates between the first sub-cavity and the braking cavity, and the fifth communication oil passage communicates between the one-way valve cavity and the braking cavity.

[0005] Further, the stopper is an adjusting screw, an upper groove is arranged at the top of the adjusting screw, a lower groove is arranged at the bottom of the adjusting screw, the upper groove and the lower groove are communicated through the communication channel, the first sub-cavity is formed between the upper groove and the top of the exhaust cavity, and the second sub-cavity is formed between the lower groove and the bottom of the exhaust cavity; an internal thread is arranged on the inner wall of the upper groove; the top of the first sub-cavity is open, and a plug is arranged at the top of the first sub-cavity, and the plug is connected to the upper groove.

[0006] Further, the exhaust valve assembly includes a plugging member, a plugging spring and a push rod; the plugging spring is connected between the plug and the plugging member, and the plugging member is arranged in the upper groove; the push rod is located in the second sub-cavity, one end of the push rod is connected to the exhaust assembly, and the other end can pass through the communication channel to contact the plugging member.

[0007] Further, the exhaust assembly includes a sliding pin and a sliding pin spring; a sliding pin groove is provided at the top of the sliding pin, and the bottom of the sliding pin is spherical; the bottom of the ejector rod is inserted into the sliding pin groove, and the sliding pin spring is sleeved outside the ejector rod; one end of the sliding pin spring is connected to the bottom of the lower groove, and the other end is connected to the ejector rod.

[0008] Further, a brake bottom opening is provided at the bottom of the brake chamber; the brake assembly includes a brake piston, a brake spring, and a brake circlip; the cross-sectional area of the upper part of the brake piston is larger than that of the lower part of the brake piston to form a brake step on the brake piston; the brake spring is connected between the top of the brake chamber and the brake piston; the brake circlip is fixed at the brake bottom opening and is clamped on the brake step.

[0009] Further, the reset chamber is provided below the one-way valve chamber, and a communication chamber is provided between the reset chamber and the one-way valve chamber; the top of the communication chamber is communicated with the bottom of the one-way valve chamber, and the bottom of the communication chamber is communicated with the top of the reset chamber; the first communication oil passage is communicated with the middle of the communication chamber.

[0010] Further, the one-way valve chamber includes a one-way valve plug and a one-way valve spring; the one-way valve spring is connected between the top of the one-way valve chamber and the one-way valve plug to press the one-way valve plug against the bottom of the one-way valve chamber; the reset assembly includes a reset piston and a reset spring; the reset spring is connected between the bottom of the reset chamber and the reset piston; the top of the reset piston passes through the communication chamber and can contact the one-way valve plug.

[0011] Further, the reset piston includes a base portion and a rod portion connected to each other; the base portion slides in the reset chamber, and the rod portion can contact the one-way valve plug; a notch is provided at the edge of the top of the base portion.

[0012] Further, a one-way valve chamber top opening is provided at the top of the one-way valve chamber, and a one-way plug is provided at the one-way valve chamber top opening; a gasket is provided at the bottom of the one-way valve chamber, and the one-way valve plug can contact the gasket; a reset chamber bottom opening is provided at the bottom of the reset chamber, a reset gasket is provided at the reset chamber bottom opening, a reset circlip is provided on the reset gasket, and the reset spring is connected to the reset circlip.

[0013] The present utility model provides a vehicle, including: a cylinder block and the above-mentioned reset type rocker arm braking device, and the rocker arm shaft is connected to the cylinder block.

[0014] It should be understood that both the foregoing general description and the following detailed description are for purposes of illustration and example only and do not necessarily limit the present disclosure. The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate the subject matter of the present disclosure. At the same time, the specification and the drawings are used to explain the principles of the present disclosure. Description of the Drawings

[0015] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following will briefly introduce the drawings required for use in the description of the specific embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0016] Figure 1 Structural schematic diagram of the reset rocker arm braking device according to an embodiment of the present invention;

[0017] Figure 2 is Figure 1 Top view of the reset rocker arm braking device shown;

[0018] Figure 3 is Figure 1 Cross-sectional view at A-A of the reset rocker arm braking device in the braking state shown;

[0019] Figure 4 is Figure 1 Cross-sectional view at A-A of the reset rocker arm braking device during the reset process shown;

[0020] Figure 5 is Figure 1 Cross-sectional view at B-B of the reset rocker arm braking device in the normal working state of the engine shown;

[0021] Figure 6 is Figure 1 Cross-sectional view at B-B of the reset rocker arm braking device during the braking process shown;

[0022] Figure 7 is Figure 1 Cross-sectional view at B-B of the reset rocker arm braking device during the reset process shown;

[0023] Figure 8 is Figure 1 Cross-sectional view at C-C of the reset rocker arm braking device in the non-braking state shown;

[0024] Figure 9 is Figure 1 Cross-sectional view at C-C of the reset rocker arm braking device in the braking state shown.

[0025] Icon:

[0026] 1 - Cam; 101 - Braking projection; 102 - Exhaust projection;

[0027] 2 - Rocker arm; 201 - Braking chamber; 202 - Check valve chamber; 203 - Reset chamber; 204 - First sub - chamber; 205 - Second sub - chamber; 206 - First connecting oil passage; 207 - Second connecting oil passage; 208 - Third connecting oil passage; 209 - Fourth connecting oil passage; 210 - Fifth connecting oil passage; 211 - Connecting chamber; 212 - Lubricating groove; 213 - Stopper; 214 - Plug; 215 - Oil drain port;

[0028] 3 - Rocker arm shaft; 301 - First shaft oil passage; 302 - Second shaft oil passage;

[0029] 4 - Roller;

[0030] 5 - Exhaust valve assembly; 501 - Sealing member; 502 - Sealing spring; 504 - Push rod;

[0031] 6 - Exhaust assembly; 601 - Slide pin; 602 - Slide pin spring;

[0032] 7 - Braking assembly; 701 - Braking piston; 702 - Braking spring; 703 - Braking circlip;

[0033] 8 - Check valve assembly; 801 - Check valve plug; 802 - Check valve spring; 803 - Check valve plug; 804 - Gasket;

[0034] 9 - Reset assembly; 901 - Reset piston; 902 - Reset spring; 903 - Notch; 904 - Reset gasket; 905 - Reset circlip;

[0035] 10 - Exhaust valve bridge;

[0036] 20 - Exhaust valve pin. Detailed implementation mode

[0037] The technical solutions of the present utility model will be clearly and completely described below in conjunction with the accompanying drawings. Obviously, the described embodiments are part of the embodiments of the present utility model, rather than all of the embodiments.

[0038] The components of the embodiments of the present utility model usually described and shown in the drawings here can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present utility model provided in the drawings is not intended to limit the scope of the claimed present utility model, but merely represents the selected embodiments of the present utility model.

[0039] Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present utility model.

[0040] In the description of the present utility model, it should be noted that the orientation or positional relationship indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present utility model 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. Therefore, it should not be construed as a limitation to the present utility model. In addition, the terms "first", "second", "third", "fourth", "fifth" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0041] In the description of the present utility model, it should be noted that unless otherwise clearly specified and defined, the terms "mounted", "connected", "coupled" shall be construed in a broad sense. For example, it may be a fixed connection, a detachable connection, or an integral connection; it may be a mechanical connection or an electrical connection; it may be directly connected or indirectly connected through an intermediate medium, and it may be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present utility model can be understood according to specific situations.

[0042] In addition, terms such as "horizontal", "vertical", "overhanging" do not mean that the components are required to be absolutely horizontal or overhanging, but may be slightly inclined. For example, "horizontal" only means that its direction is more horizontal relative to "vertical", and does not mean that the structure must be completely horizontal, but may be slightly inclined.

[0043] Such as Figures 1 to 9As shown in the figure, the present utility model provides a reset rocker arm braking device, comprising: a cam 1, along the circumferential direction of the cam, braking protrusions 101 and exhaust protrusions 102 are arranged at intervals on the cam 1, and the height of the braking protrusion 101 is less than the height of the exhaust protrusion 102; a rocker arm assembly, comprising a rocker arm 2, a rocker arm shaft 3 and a roller 4; the rocker arm 2 is used for rotatably connecting with a cylinder block through the rocker arm shaft 3, the roller 4 is rotatably arranged at the first end of the rocker arm 2, and the second end of the rocker arm 2 is provided with an exhaust cavity, a braking cavity 201, a check valve cavity 202 and a reset cavity 203; the rocker arm shaft 3 is provided with a first shaft oil passage 301 and a second shaft oil passage 302, and the rocker arm 2 is provided with a first communication oil passage 206, a second communication oil passage 207, a third communication oil passage 208, a fourth communication oil passage 209 and a fifth communication oil passage 210; a stopper 213 is arranged in the exhaust cavity, and a communication channel is arranged on the stopper 213 to divide the exhaust cavity into a first sub-cavity 204 and a second sub-cavity 205 which are connected; an exhaust valve assembly 5 is arranged in the first sub-cavity 204, and the exhaust valve assembly 5 is used for switching the communication channel between the first sub-cavity 204 and the second sub-cavity 205; an exhaust assembly 6 is arranged in the second sub-cavity 205, and the exhaust assembly 6 is used for contacting an exhaust valve bridge 10, and a first set gap is arranged between the exhaust assembly 6 and the stopper 213; a braking assembly 7 is arranged in the braking cavity 201, and the braking assembly 7 is used for contacting an exhaust valve pin 20; a check valve assembly 8 is arranged in the check valve cavity 202, a reset assembly 9 is arranged in the reset cavity 203, and an oil drain port 215 is arranged on the reset cavity 203; the first communication oil passage 206 is communicated between the first shaft oil passage 301 and the check valve cavity 202, the second communication oil passage 207 is communicated between the second shaft oil passage 302 and the reset cavity 203, the third communication oil passage 208 is communicated between the reset cavity 203 and the second sub-cavity 205, the fourth communication oil passage 209 is communicated between the first sub-cavity 204 and the braking cavity 201, and the fifth communication oil passage 210 is communicated between the check valve cavity 202 and the braking cavity 201.

[0044] In this embodiment, when the engine is operating normally, the one-way valve assembly 8 maintains an open state of the passage between the one-way valve chamber 202 and the brake chamber 201; the engine oil in the cylinder enters the rocker shaft 3 through the first shaft oil passage 301, the first communication oil passage 206, the one-way valve chamber 202, and the fifth communication oil passage 210 and enters the one-way valve chamber 202. Part of the engine oil enters the second shaft oil passage 302 and the second communication oil passage 207 and then enters the reset chamber 203, and then enters the second sub-chamber 205 through the third communication oil passage 208, and the oil plays a lubricating role. The brake assembly 7 is always in contact with the exhaust valve pin 20, and the reset assembly 9 is in contact with the top of the reset chamber 203. When the cam rotates until the braking protrusion contacts the roller 4, since there is a first set clearance reserved between the exhaust assembly 6 and the stopper 213, and the lift generated by the braking protrusion is not sufficient to eliminate the first set clearance, the exhaust assembly 6 does not push the exhaust valve bridge 10 to move, and the exhaust valve cannot be opened to achieve the exhaust function. The one-way valve assembly 8 is in the open state. Therefore, when the brake assembly 7 is subjected to the acting force of the exhaust valve pin 20, the oil in the one-way valve flows back along the fourth communication oil passage 209, the first communication oil passage 206, and the first shaft oil passage 301. The brake chamber 201 cannot form a sealed chamber, and the brake assembly 7 cannot push the exhaust valve pin 20 to open the exhaust valve. At the same time, due to the acting force of the exhaust valve pin 20, the returned engine oil has a relatively high oil pressure. After the engine oil with a relatively high pressure flows back into the lubricating groove 212 between the rocker shaft 3 and the rocker 2, the lubricating effect can be improved and the wear between the rocker shaft 3 and the shaft hole can be reduced.

[0045] When the cam rotates until the exhaust protrusion contacts the roller 4, at this time the valve lift is relatively large. After the exhaust assembly 6 makes up for the reserved first set clearance, there is still enough valve lift to cause the exhaust valve to act, so as to open the exhaust valve to achieve the normal exhaust action. The exhaust valve pin 20 moves along with the exhaust valve bridge 10, so that the brake assembly 7 is disengaged from the exhaust valve pin 20.

[0046] When the braking is activated, braking fluid (fluid meeting certain pressure requirements) is supplied to the second shaft oil passage 302. The braking fluid enters the reset cavity 203 through the second communication oil passage 207. The fluid can enter the check valve cavity 202 through the reset cavity 203, and then enter the braking cavity 201 through the fifth communication oil passage 210. The fluid enters the second sub-cavity 205 after entering the third communication oil passage 208 from the reset cavity 203. At this time, the check valve assembly 8 closes the passage between the check valve cavity 202 and the braking cavity 201. The braking cavity 201 forms a sealed cavity. When the cam rotates to the braking protrusion, since the oil in the braking cavity 201 cannot be discharged, a hydraulic tappet structure is formed with the braking assembly 7 to open the exhaust valve to achieve braking. In each braking cycle, when the rocker arm 2 rotates through a certain angle, the exhaust valve assembly 5 opens, so that a sealed cavity cannot be formed in the braking cavity 201 and the braking fails to achieve the reset function. During the reset process, due to the acting force of the exhaust valve pin 20 on the braking assembly 7, the oil pressure of the braking fluid in the braking cavity 201 increases. The braking fluid flows through the braking cavity 201, the fourth communication oil passage 209, the second sub-cavity 205, the third communication oil passage 208, and the reset cavity 203 in sequence. At this time, the reset assembly 9 exposes the oil drain hole, and the braking fluid drains to the outside from the oil drain hole. After the reset process is completed, the exhaust and oil inlet processes are carried out. During the oil inlet stage, the exhaust valve pin resets, the braking piston no longer moves, and the rocker arm swings upward continuously as the cam swings, increasing the volume of the volume cavity. At this time, the volume in the check valve cavity 202 increases and the oil pressure decreases, and the braking fluid enters the check valve cavity 202 again.

[0047] In this embodiment, during the oil inlet process, the braking assembly 7 moves downward to increase the volume of the braking cavity 201, so that the oil pressure in the sealed cavity is lower than the oil pressure in the oil passage, accelerating the oil inlet rate. Thus, the braking performance of the engine can be stable at high speeds, avoiding excessive cylinder pressure and extending the service life of the braking device.

[0048] As Figure 3 and Figure 4 shown, the blocking member 213 is an adjusting screw. The top of the adjusting screw is provided with an upper groove, and the bottom of the adjusting screw is provided with a lower groove. The upper groove and the lower groove are communicated through a communication channel. The upper groove and the top of the exhaust cavity form a first sub-cavity 204, and the lower groove and the bottom of the exhaust cavity form a second sub-cavity 205; the inner wall of the upper groove is provided with an internal thread; the top of the first sub-cavity 204 is open, and a plug 214 is provided at the top of the first sub-cavity 204. The plug 214 is connected to the upper groove.

[0049] The structure of the blocking member 213 in this embodiment is convenient for installation and fixation in the exhaust cavity, and it is also convenient for the plug to block the top of the first sub-cavity 204.

[0050] As Figure 3 and Figure 4As shown in the figure, based on the above embodiments, further, the exhaust valve assembly 5 includes a plugging member 501, a plugging spring 502, and a push rod 504; the plugging spring 502 is connected between the plug 214 and the plugging member 501, and the plugging member 501 is disposed in the upper groove; the push rod 504 is located in the second sub-chamber 205, one end of the push rod 504 is connected to the exhaust assembly 6, and the other end can pass through the communication channel and contact the plugging member 501.

[0051] In the exhaust valve assembly 5 of this embodiment, instead of using a solenoid valve or an electric valve, a mechanical structure is adopted to realize the opening and closing of the communication channel, which has reliable installation and low cost.

[0052] As Figure 3 and Figure 4 shown in the figure, based on the above embodiments, further, the exhaust assembly 6 includes a sliding pin 601 and a sliding pin spring 602; a sliding pin groove is provided at the top of the sliding pin 601, and the bottom of the sliding pin 601 is spherical; the bottom of the push rod 504 is inserted into the sliding pin groove, and the sliding pin spring 602 is sleeved outside the push rod 504; one end of the sliding pin spring 602 is connected to the bottom of the lower groove, and the other end is connected to the push rod 504.

[0053] The structure in the exhaust chamber of this embodiment is compact and occupies less space.

[0054] As Figure 8 and Figure 9 shown in the figure, based on the above embodiments, further, a brake bottom opening is provided at the bottom of the brake chamber 201; the brake assembly 7 includes a brake piston 701, a brake spring 702, and a brake snap ring 703; the cross-sectional area of the upper part of the brake piston 701 is larger than that of the lower part of the brake piston 701 to form a brake step on the brake piston 701; the brake spring 702 is connected between the top of the brake chamber 201 and the brake piston 701; the brake snap ring 703 is fixed at the brake bottom opening and is clamped on the brake step. The brake assembly 7 provided in this embodiment has a simple structure.

[0055] As Figures 5 to 7 shown in the figure, based on the above embodiments, further, the reset chamber 203 is disposed below the check valve chamber 202, and a communication chamber 211 is provided between the reset chamber 203 and the check valve chamber 202; the top of the communication chamber 211 is communicated with the bottom of the check valve chamber 202, and the bottom of the communication chamber 211 is communicated with the top of the reset chamber 203; the first communication oil passage 206 is communicated with the middle of the communication chamber 211. Such a setting can make the structure of the reset type rocker brake device compact.

[0056] As Figures 5 to 7As shown, on the basis of the above embodiments, further, the one-way valve chamber 202 includes a one-way valve plug 801 and a one-way valve spring 802; the one-way valve spring 802 is connected between the top of the one-way valve chamber 202 and the one-way valve plug 801 to press the one-way valve plug 801 against the bottom of the one-way valve chamber 202; the reset assembly 9 includes a reset piston 901 and a reset spring 902; the reset spring 902 is connected between the bottom of the reset chamber 203 and the reset piston 901; the top of the reset piston 901 can contact the one-way valve plug 801 through the communication chamber 211.

[0057] In this embodiment, the one-way valve plug 801 in the one-way valve assembly 8 and the brake fluid are controlled by the reset piston 901 in the reset assembly 9 to open or close the fifth communication oil passage, making the structure of the reset rocker arm braking device compact.

[0058] As Figures 5 to 7 shown, on the basis of the above embodiments, further, the reset piston 901 includes a base portion and a rod portion connected to each other; the base portion slides in the reset chamber 203, and the rod portion can contact the one-way valve plug 801; a notch 903 is provided at the edge of the top of the base portion.

[0059] In this embodiment, by providing a notch at the top of the base portion, a larger space can be formed between the base portion and the top of the reset chamber 203, facilitating the movement of the reset piston 901 by the oil.

[0060] As Figures 5 to 7 shown, on the basis of the above embodiments, further, a one-way valve chamber 202 top opening is provided at the top of the one-way valve chamber 202, and a one-way plug 803 is provided at the one-way valve chamber 202 top opening; a gasket 804 is provided at the bottom of the one-way valve chamber 202, and the one-way valve plug 801 can contact the gasket 804; a reset chamber 203 bottom opening is provided at the bottom of the reset chamber 203, and a reset gasket 904 is provided at the reset chamber 203 bottom opening, a reset circlip 905 is provided on the reset gasket 904, and the reset spring 902 is connected to the reset circlip 905.

[0061] An electromagnetic valve can be provided on the rocker arm shaft 3 support, the rocker arm shaft 3 support is fixed to the cylinder block, and the electromagnetic valve controls the oil pressure entering the second shaft oil passage 302.

[0062] In some alternative solutions, the working process of the reset rocker arm braking device is as follows:

[0063] When the engine is operating normally, the one-way valve assembly 8 maintains an open state for the passage between the one-way valve chamber 202 and the brake chamber 201; the engine oil in the cylinder enters the rocker shaft 3 through the first shaft oil passage 301, the first communication oil passage 206, the one-way valve chamber 202, and the fifth communication oil passage 210 and enters the one-way valve chamber 202. Part of the engine oil will enter the second shaft oil passage 302 and the second communication oil passage 207 to enter the reset chamber 203, and then enter the second sub-chamber 205 through the third communication oil passage 208, and the oil plays a lubricating role. The brake piston 701 is always in contact with the exhaust valve pin 20 under the action of the brake spring 702, and the reset piston 901 is always in contact with the top of the reset chamber 203 under the action of the reset spring 902. At the same time, the rod portion of the reset piston 901 pushes open the one-way valve stopper 801, and the one-way valve assembly 8 is in an open state, that is, the passage between the one-way valve chamber 202 and the brake chamber 201 is opened. When the cam rotates until the brake projection contacts the roller 4, since there is a first set clearance reserved between the sliding pin 601 and the stopper 213 and the lift generated by the brake projection is not sufficient to eliminate the first set clearance, the sliding pin 601 cannot push the exhaust valve bridge 10 to open the exhaust valve to achieve the exhaust function. Since the one-way valve assembly 8 is in an open state, when the brake piston 701 is subjected to the force of the exhaust valve pin 20, the oil in the brake chamber 201 will flow back along the fifth communication oil passage 210, the one-way valve chamber 202, the communication chamber 211, the first communication oil passage 206, and the first shaft oil passage 301, and a sealed chamber cannot be formed. At this time, the exhaust valve will not open. At the same time, due to the force of the exhaust valve pin 20, the returned engine oil has a relatively high oil pressure. After the engine oil with a relatively high pressure flows back into the lubrication groove 212 between the rocker shaft 3 and the rocker 2, the lubrication effect can be improved and the wear between the rocker shaft 3 and the shaft hole can be reduced. When the cam rotates until the exhaust projection contacts the roller 4, at this time the valve lift is relatively large. After the sliding pin 601 makes up for the reserved first set clearance, there is still enough valve lift to make the exhaust valve act, so as to open the exhaust valve to achieve the normal exhaust action, and the brake piston 701 will be limited by the brake snap ring 703 and separated from the exhaust valve pin 20.

[0064] When the braking is activated, under the action of the solenoid valve, the braking oil enters the second shaft oil passage 302, the second communication oil passage 207, the reset chamber 203, the third communication oil passage 208 and the second sub-chamber 205; the braking oil can enter the one-way valve chamber 202 from the reset chamber 203 and then enter the braking chamber 201 through the fifth communication oil passage; under the action of the braking oil, the reset piston 901 will displace downward by a certain distance, but due to the action of the reset spring 902, the reset piston 901 still blocks the oil drain port 215. At the same time, due to the downward movement of the reset piston 901 and under the action of the one-way valve spring 802, the one-way valve plug 801 closes the fifth communication oil passage 210. At this time, the braking chamber 201 forms a sealed chamber. When the cam rotates to the braking protrusion, since the oil in the braking chamber 201 cannot be discharged, a hydraulic tappet structure is formed with the braking piston 701 to open the exhaust valve to achieve braking. In each braking cycle, when the rocker arm 2 rotates through a certain angle (when the roller is at the highest point near the braking protrusion), the exhaust plug 501 will contact the push rod 504, and under the action of the valve spring force and the cylinder pressure, the exhaust plug 501 moves upward, so that a sealed chamber cannot be formed in the braking chamber 201 and the braking fails to achieve the reset function (during the oil inlet process, the exhaust plug 501 is in the state of closing the communication channel; during the exhaust process, the exhaust plug 501 opens the communication channel, but in the non-braking state, the one-way valve plug 801 is in the normally open state, so whether the exhaust plug 501 is open or not does not affect the overall function). During the reset process, due to the force of the exhaust valve on the braking piston 701, the oil pressure of the braking oil in the braking valve increases, and the braking oil flows through the braking chamber 201, the fourth communication oil passage 209, the first sub-chamber 204, the second sub-chamber 205, the third communication oil passage 208, and the reset chamber 203 in sequence. Since the oil pressure in the reset chamber 203 is relatively high at this time, the reset piston 901 moves downward again to expose the oil drain hole, and the braking oil drains to the outside from the oil drain hole. After the reset process ends, it enters the braking oil inlet stage. In the oil inlet stage, the braking piston 701 moves downward under the action of the braking spring 702. At this time, the volume in the braking chamber 201 increases and the oil pressure decreases, and the braking oil enters the braking chamber 201 again. After the solenoid valve is closed, the oil pressure in the reset chamber 203 decreases, and the reset piston 901 resets under the action of the reset spring 902. At this time, the engine resumes normal operation.

[0065] The reset rocker arm braking device provided by the embodiment of the present invention can improve the oil inlet rate, make the braking performance more stable, reduce the in-cylinder pressure during braking and improve the overall reliability. The slip pin spring 602 is integrated in the slip pin 601, which can reduce the wear of the roller 4; the first shaft oil passage 301 is connected to the lubricating oil groove at the bottom of the shaft hole. When the oil in the sealed chamber is compressed, the oil pressure in the oil inlet passage will increase, improving the lubrication effect.

[0066] An embodiment of the present utility model further provides a vehicle, which includes a cylinder block and the reset rocker arm braking device of any one of the above technical solutions, and the rocker arm shaft 3 is connected to the cylinder block. Therefore, the vehicle has all the beneficial technical effects of the reset rocker arm braking device, and will not be elaborated herein.

[0067] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present utility model and are not intended to limit them; although the present utility model has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements on some or all of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present utility model. In the specification provided herein, a large number of specific details are described. However, it can be understood that the embodiments of the present utility model can be practiced without these specific details. In some instances, well-known methods, structures, and technologies have not been shown in detail so as not to obscure the understanding of this specification. In addition, those skilled in the art can understand that although some of the embodiments described herein include certain features included in other embodiments but not other features, the combination of the features of different embodiments means that it is within the scope of the present utility model and forms different embodiments.

Claims

1. A reset rocker arm braking device, characterized in that, Comprising: A cam, along the circumferential direction of the cam, braking protrusions and exhaust protrusions are spaced on the cam, and the height of the braking protrusion is less than the height of the exhaust protrusion; A rocker arm assembly, including a rocker arm, a rocker arm shaft and a roller; the rocker arm is rotatably connected to the cylinder block through the rocker arm shaft, the roller is rotatably arranged at the first end of the rocker arm, and an exhaust cavity, a braking cavity, a check valve cavity and a reset cavity are arranged at the second end of the rocker arm; a first shaft oil passage and a second shaft oil passage are arranged on the rocker arm shaft, and a first communication oil passage, a second communication oil passage, a third communication oil passage, a fourth communication oil passage and a fifth communication oil passage are arranged on the rocker arm; a stopper is arranged in the exhaust cavity, and a communication passage is arranged on the stopper to divide the exhaust cavity into a first sub-cavity and a second sub-cavity including a connection; An exhaust valve assembly is arranged in the first sub-cavity, and the exhaust valve assembly is used to switch the communication passage between the first sub-cavity and the second sub-cavity; an exhaust assembly is arranged in the second sub-cavity, and the exhaust assembly is used to contact the exhaust valve bridge, and a first set gap is arranged between the exhaust assembly and the stopper; a braking assembly is arranged in the braking cavity, and the braking assembly is used to contact the exhaust valve pin; a check valve assembly is arranged in the check valve cavity, a reset assembly is arranged in the reset cavity, and an oil drain port is arranged on the reset cavity; The first communication oil passage communicates between the first shaft oil passage and the check valve cavity, the second communication oil passage communicates between the second shaft oil passage and the reset cavity, the third communication oil passage communicates between the reset cavity and the second sub-cavity, the fourth communication oil passage communicates between the first sub-cavity and the braking cavity, and the fifth communication oil passage communicates between the check valve cavity and the braking cavity.

2. The reset rocker arm braking device according to claim 1, characterized in that The stopper is an adjusting screw, an upper groove is arranged at the top of the adjusting screw, a lower groove is arranged at the bottom of the adjusting screw, the upper groove and the lower groove are communicated through the communication passage, the upper groove and the top of the exhaust cavity form the first sub-cavity, and the lower groove and the bottom of the exhaust cavity form the second sub-cavity; internal threads are arranged on the inner wall of the upper groove; The top of the first sub-cavity is open, and a plug is arranged at the top of the first sub-cavity, and the plug is connected to the upper groove.

3. The reset rocker arm braking device according to claim 2, characterized in that The exhaust valve assembly includes a plugging member, a plugging spring and a push rod; The plugging spring is connected between the plug and the plugging member, and the plugging member is arranged in the upper groove; The push rod is located in the second sub-cavity, one end of the push rod is connected to the exhaust assembly, and the other end can pass through the communication passage and contact the plugging member.

4. The reset rocker arm braking device according to claim 3, characterized in that The exhaust assembly includes a sliding pin and a sliding pin spring; A sliding pin groove is arranged at the top of the sliding pin, and the bottom of the sliding pin is spherical; The bottom of the ejector rod is inserted into the slide pin groove, and the slide pin spring is sleeved outside the ejector rod; one end of the slide pin spring is connected to the bottom of the lower groove, and the other end is connected to the ejector rod.

5. The reset rocker arm braking device according to claim 1, wherein The bottom of the braking cavity is provided with a braking bottom opening; The braking assembly includes a braking piston, a braking spring, and a braking snap ring; The cross-sectional area of the upper part of the braking piston is larger than the cross-sectional area of the lower part of the braking piston, so as to form a braking step on the braking piston; The braking spring is connected between the top of the braking cavity and the braking piston; The braking snap ring is fixed at the braking bottom opening and is clamped on the braking step.

6. The reset rocker arm braking device according to any one of claims 1-5, wherein The reset cavity is arranged below the one-way valve cavity, and a communication cavity is provided between the reset cavity and the one-way valve cavity; the top of the communication cavity is communicated with the bottom of the one-way valve cavity, and the bottom of the communication cavity is communicated with the top of the reset cavity; The first communication oil passage is communicated with the middle of the communication cavity.

7. The reset rocker arm braking device according to claim 6, wherein The one-way valve cavity includes a one-way valve plug and a one-way valve spring; the one-way valve spring is connected between the top of the one-way valve cavity and the one-way valve plug to press the one-way valve plug against the bottom of the one-way valve cavity; The reset assembly includes a reset piston and a reset spring; the reset spring is connected between the bottom of the reset cavity and the reset piston; the top of the reset piston passes through the communication cavity and can contact the one-way valve plug.

8. The reset rocker arm braking device according to claim 7, wherein The reset piston includes a base portion and a rod portion connected to each other; the base portion slides in the reset cavity, and the rod portion can contact the one-way valve plug; A notch is provided at the edge of the top of the base portion.

9. The reset rocker arm braking device according to claim 7, wherein The top of the one-way valve cavity is provided with a one-way valve cavity top opening, and a one-way plug is provided at the one-way valve cavity top opening; a gasket is provided at the bottom of the one-way valve cavity, and the one-way valve plug can contact the gasket; The bottom of the reset cavity is provided with a reset cavity bottom opening, a reset gasket is provided at the reset cavity bottom opening, a reset snap ring is provided on the reset gasket, and the reset spring is connected to the reset snap ring.

10. A vehicle, characterized in that, Comprising: A cylinder block and the reset rocker arm braking device according to any one of claims 1-9, and the rocker arm shaft is connected to the cylinder block.

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