Engine-specific hydraulic lost rocker arm brake and engine thereof

Abstract

The present invention relates to the technical field of valve drive devices, and in particular to an engine-specific hydraulic lost rocker arm brake and its engine, the brake comprising a brake cam, a brake rocker arm and a self-unlocking locking unit, the self-unlocking locking unit having a locking block and a locking elastic element, wherein the self-unlocking locking unit locks the brake rocker arm sleeved on the rocker arm shaft by the locking block when the engine is working, thereby fixing the brake rocker arm, thereby avoiding the noise and wear problems caused by the easy swing of the brake rocker arm when the engine is working, and in the process of supplying oil to the brake oil circuit by the oil supply circuit to extend the piston during engine braking, the locking block will be pushed by the oil in the oil supply circuit to displace and automatically unlock the brake rocker arm, thereby restoring the rotatable characteristic of the brake rocker arm, so that the brake cam can drive the brake valve to complete the brake lift through the brake rocker arm, and the whole process does not require additional control operations, and the control is simple.

Description

Technical Field

[0001] The present invention relates to the technical field of valve drive devices, in particular to a hydraulic type lost motion rocker arm brake dedicated to an engine, and also to an engine comprising the hydraulic type lost motion rocker arm brake dedicated to the engine. Background Art

[0002] The efficient, continuous and stable deceleration performance engine brake can effectively brake the engine and slow down the vehicle. In the development and research of such engine brake, there are still many deficiencies. For example, a four-stroke internal combustion engine valve mechanism and its exhaust cam are disclosed in the Chinese patent with publication number CN210003346U, which records that the integrated rocker arm is rotatably mounted on the rocker arm shaft, the exhaust cam is arranged on the camshaft, the integrated rocker arm includes an exhaust rocker arm and a brake rocker arm integrated together, and a piston driven by a hydraulic control device is arranged at the front end of the brake rocker arm. The piston retracts during positive power and extends to press down one of the exhaust valves during braking.

[0003] The problem with this type of engine valve mechanism is that when braking, the exhaust cam needs to drive the brake rocker arm to rotate around the rocker arm shaft through its rotation, and the piston pushes the valve as the brake rocker arm rotates. Although the brake rocker arm does not participate in the work when the engine is working normally, the brake rocker arm installed on the rocker arm shaft will easily swing, resulting in increased noise, friction consumption of positive working energy, and easy wear of the brake rocker arm. Summary of the invention

[0004] The technical problem to be solved by the present invention is: in order to solve the problem that the engine brake in the prior art is easy to swing and cause noise and wear, a hydraulic lost arm brake dedicated to an engine is provided, and an engine including the above-mentioned hydraulic lost arm brake dedicated to the engine is also provided.

[0005] The technical solution adopted by the present invention to solve the technical problem is: a hydraulic type lost rocker arm brake dedicated to an engine, comprising:

[0006] A brake cam having a base circle portion and a brake lift boss protruding from the base circle portion;

[0007] A brake rocker arm, comprising a cam follower unit, a brake oil circuit, a shaft hole and a piston hole, wherein a piston is slidably mounted in the piston hole, the shaft hole of the brake rocker arm is sleeved on a rocker arm shaft of the engine, the rocker arm shaft is located between the cam follower unit and the piston, and the brake oil circuit is communicated with the piston hole;

[0008] and a self-unlocking locking unit, comprising a locking block and a locking elastic element, wherein the brake rocker arm has a sliding hole, the locking block is slidably mounted in the sliding hole, and the locking elastic element is used to push the locking block to move toward the rocker arm shaft;

[0009] The locking elastic element pushes the locking block to move until the locking block cooperates with the limiting swing structure of the rocker arm shaft, and the braking rocker arm is locked on the rocker arm shaft by the locking block;

[0010] The oil supply circuit supplies oil, and the oil in the oil supply circuit pushes the locking block, so that the locking block overcomes the elastic force of the locking elastic element and leaves the limiting swing structure to unlock the brake rocker arm, and the oil in the oil supply circuit enters the piston hole through the brake oil circuit to push the piston to extend toward the brake valve direction, so that when the cam follower unit contacts the brake cam, the rotating brake cam and the cam follower unit slide or roll to cooperate to drive the brake rocker arm to rotate, and the piston rotates with the brake rocker arm to provide power for the engine's brake valve to move relative to the valve bridge.

[0011] Furthermore, the brake rocker arm also has a pressure relief oil circuit connected to the brake oil circuit, and the oil drain port of the pressure relief oil circuit extends to the inner wall of the sliding hole;

[0012] When the brake rocker arm is locked on the rocker arm shaft by the locking block, the locking block blocks the oil supply path, so that the oil supply path is not connected to the brake oil path, and the locking block is away from the oil drain port, so that the oil drain port is open;

[0013] When the locking block unlocks the brake rocker arm, the locking block releases the blockage of the oil supply path, so that the oil supply path is connected to the brake oil path, and the locking block moves to the oil drain port to block the oil drain port.

[0014] Furthermore, the swing limiting structure is a locking groove opened on the rocker shaft, and a locking protrusion extends from one end of the locking block close to the rocker shaft. When the locking protrusion is embedded in the locking groove, the braking rocker is locked on the rocker shaft by the locking block.

[0015] Furthermore, when the locking protrusion is embedded in the locking groove, a gap is left between the locking protrusion and the locking groove on one side or both sides in the rotation direction of the brake rocker arm;

[0016] The locking protrusion has a positioning portion at one end close to the locking groove, the bottom of the locking groove has a positioning surface matching the positioning portion, and the cross-sectional area of ​​the positioning portion gradually decreases along the direction from the locking block to the rocker arm shaft;

[0017] When the positioning portion is embedded in the positioning surface so that the locking protrusion is guided and positioned in the locking groove, the brake rocker arm is locked on the rocker arm shaft by the locking block.

[0018] Furthermore, the positioning portion is in a spherical cap shape, a hemispherical shape, a V shape, an arc shape or a cone shape.

[0019] Furthermore, the outlet of the oil supply circuit is located at the bottom of the locking groove, the oil supply circuit is connected with the brake oil circuit through the locking groove, and the locking protrusion blocks the outlet of the oil supply circuit when it abuts against the bottom of the locking groove.

[0020] Furthermore, one end of the sliding hole extends to the outer wall surface of the brake rocker arm, and the other end extends to the inner wall surface of the shaft hole. The end of the locking elastic element away from the rocker arm shaft presses against the brake rocker arm, and the end of the locking elastic element close to the rocker arm shaft presses against the locking block.

[0021] Furthermore, the oil supply circuit and / or the brake oil circuit is provided with a one-way component, and the one-way component is used to allow oil to flow from the oil supply circuit to the brake oil circuit, but prevent oil from flowing from the brake oil circuit to the oil supply circuit.

[0022] Furthermore, the one-way component is arranged on the brake oil circuit;

[0023] The one-way assembly includes a fastener, a valve elastic element and a valve core. The brake oil circuit has at least one section of a variable diameter hole along its extension trajectory. The variable diameter hole has a fine hole section and a coarse hole section that are connected to each other. The cross-sectional area of ​​the coarse hole section is larger than the cross-sectional area of ​​the fine hole section. A step surface is formed between the fine hole section and the coarse hole section. The fastener is detachably fixed on the brake rocker arm and blocks one end of the coarse hole section away from the fine hole section.

[0024] The valve elastic element and the valve core are located in the coarse hole section, one end of the valve elastic element abuts against the fastener or the brake rocker arm, and the other end abuts against the valve core, and the valve core abuts against the step surface to block the connection between the fine hole section and the coarse hole section.

[0025] Furthermore, the brake rocker arm is provided with a brake elastic element for moving the piston in a direction away from the brake valve;

[0026] When the oil in the brake oil circuit causes the piston to overcome the elastic force of the brake elastic element, the oil in the brake oil circuit pushes the piston to extend toward the brake valve to an open position; when the pressure relief oil circuit releases oil, the brake elastic element drives the piston to retract.

[0027] Furthermore, when the braking rocker arm is locked on the rocker arm shaft by the locking block, the braking cam is separated from the cam follower unit, so that the braking cam does not contact the cam follower unit during the rotation process.

[0028] Furthermore, when the positive power rocker arm of the engine does not drive the valve bridge to move and the oil supply circuit supplies oil to unlock the brake rocker arm, when the brake cam rotates to the point where the base circle is directly opposite the cam follower unit, the oil in the brake oil circuit pushes the piston to extend to abut the brake valve, thereby forcing the brake rocker arm to rotate and causing the cam follower unit to contact the base circle; when the brake cam rotates to the point where the brake lift boss slides or rolls with the cam follower unit, the brake lift boss drives the brake rocker arm to rotate, and the piston rotates with the brake rocker arm to provide power for the engine's brake valve to move relative to the valve bridge.

[0029] The present invention also provides an engine, comprising the above-mentioned engine-specific hydraulic lost arm brake.

[0030] The beneficial effects of the present invention are as follows: the engine-specific hydraulic lost rocker arm brake of the present invention uses a self-unlocking locking unit to lock the brake rocker arm sleeved on the rocker arm shaft by a locking block when the engine is working, so as to fix the brake rocker arm, thereby avoiding the noise and wear problems caused by the easy swing of the brake rocker arm when the engine is working, and in the process of supplying oil to the brake oil circuit by the oil supply circuit to extend the piston during engine braking, the locking block will be pushed by the oil in the oil supply circuit to displace and automatically unlock the brake rocker arm, thereby restoring the rotatable characteristics of the brake rocker arm, so that the brake cam can drive the brake valve to complete the brake lift through the brake rocker arm, and the whole process does not require additional control operations, and the control is simple. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] The present invention is further described below in conjunction with the accompanying drawings and embodiments.

[0032] Figure 1 It is a schematic diagram of the brake rocker arm of the engine-specific hydraulic lost rocker arm brake of the present invention when being locked;

[0033] Figure 2 is a schematic diagram of a self-unlocking locking unit in the present invention;

[0034] Figure 3 It is a schematic diagram of the piston being mounted on the brake rocker arm;

[0035] Figure 4 It is a three-dimensional schematic diagram of the engine-specific hydraulic lost rocker arm brake of the present invention;

[0036] Figure 5 It is a schematic diagram of the cooperation between the base circle of the brake cam and the cam follower unit when the brake rocker arm of the present invention is unlocked;

[0037] Figure 6 It is a schematic diagram of the cooperation between the brake lift boss of the brake cam and the cam follower unit when the brake rocker arm of the present invention is unlocked;

[0038] Figure 7 It is a schematic diagram of the locking block of the present invention extending into the locking groove but the positioning portion has not yet contacted the positioning surface.

[0039] In the figure: 1, brake cam, 1-1, base circle, 1-2, brake lift boss;

[0040] 2. Braking rocker arm, 2-1. Cam follower unit, 2-2. Braking oil circuit, 2-21. Variable diameter hole, 2-211. Coarse hole section, 2-212. Fine hole section, 2-3. Pressure relief oil circuit, 2-31. Oil drain port, 2-4. Shaft hole, 2-5. Piston hole, 2-6. Sliding hole;

[0041] 3. Self-unlocking locking unit, 3-1. Locking block, 3-11. Locking protrusion, 3-111. Positioning portion, 3-12. Spring cavity, 3-2. Locking elastic element, 3-3. Gap, 3-4. First limiting member;

[0042] 4. Piston, 41. Inner hole;

[0043] 5. Braking elastic element;

[0044] 6. The second limiter;

[0045] 7, rocker arm shaft, 7-1, swing limiting structure, 7-11, locking groove, 7-111, positioning surface, 7-2, oil supply passage, 7-21, outlet;

[0046] 8. One-way assembly, 8-1. Valve core, 8-2. Valve elastic element;

[0047] 9. Positive power cam, 10. Positive power rocker arm, 11. Valve bridge, 12. Brake valve, 13. Valve pin, 14. Non-brake valve, 15. Adjusting bolt, 16. Camshaft. DETAILED DESCRIPTION

[0048] The present invention will now be described in further detail with reference to the accompanying drawings. These drawings are simplified schematic diagrams that only illustrate the basic structure of the present invention in a schematic manner, and therefore only show the components related to the present invention, and directions and references (e.g., up, down, left, right, etc.) may only be used to help describe the features in the drawings. Therefore, the following specific embodiments are not to be taken in a limiting sense, and the scope of the subject matter claimed is limited only by the attached claims and their equivalents.

[0049] like Figure 1-6 As shown, a hydraulic type lost motion rocker arm brake for an engine comprises a brake cam 1, a brake rocker arm 2 and a self-unlocking locking unit 3; the engine is a four-stroke engine, a part of the exhaust valves in the valve group of the engine are brake valves 12, and another part of the exhaust valves are non-brake valves 14;

[0050] The brake cam 1 has a base circle 1-1 and a brake lift boss 1-2 protruding from the base circle 1-1. The brake cam 1 can be installed on one side of the positive power cam 9 of the engine. The camshaft 16 of the engine drives the positive power cam 9 and the brake cam 1 to rotate. The brake cam 1 has at least one brake lift boss 1-2; for example, there are two brake lift bosses 1-2, one brake lift boss 1-2 is a brake BGR lift boss, which enables the brake valve 12 to perform an exhaust gas recirculation operation to compress more gas and improve the braking power; the other brake lift boss 1-2 is a brake CR lift boss, which performs a compression release operation to achieve braking;

[0051] The brake rocker arm 2 has a cam follower unit 2-1, a brake oil circuit 2-2, an axial hole 2-4 and a piston hole 2-5. A piston 4 is slidably installed in the piston hole 2-5. The axial hole 2-4 of the brake rocker arm 2 is sleeved on the rocker arm shaft 7 of the engine. When braking, the brake cam 1 rotates one circle with the cam shaft 16, and the base circle 1-1 and the brake lift boss 1-2 will pass through the cam follower unit 2-1 one by one. The rocker arm shaft 7 is located between the cam follower unit 2-1 and the piston 4. The brake oil circuit 2-2 is connected with the piston hole 2-5. When the brake oil circuit 2-2 is oiled, the piston 4 extends;

[0052] It is worth noting that the cam follower unit 2-1 can be the outer wall surface of the brake rocker arm 2 away from the piston 4. At this time, when the brake cam 1 and the cam follower unit 2-1 are matched, the brake cam 1 and the outer wall surface of the cam follower unit 2-1 are in contact, and the brake cam 1 and the cam follower unit 2-1 can be regarded as a sliding match;

[0053] The cam follower unit 2-1 may also be a roller rotatably mounted on the brake rocker arm 2. In this case, when the brake cam 1 and the cam follower unit 2-1 are in cooperation, the brake cam 1 and the roller of the cam follower unit 2-1 are in contact, and the brake cam 1 and the cam follower unit 2-1 can be regarded as rolling cooperation.

[0054] The cam follower unit 2-1 can also be an elastically retractable component installed on the brake rocker arm 2. At this time, when the brake cam 1 and the cam follower unit 2-1 are matched, the brake cam 1 and the cam follower unit 2-1 are in contact, and the brake cam 1 and the cam follower unit 2-1 can be regarded as a sliding match.

[0055] The self-unlocking locking unit 3 has a locking block 3-1 and a locking elastic element 3-2. The brake rocker arm 2 has a sliding hole 2-6. The locking block 3-1 is slidably installed in the sliding hole 2-6. The locking elastic element 3-2 is used to push the locking block 3-1 to move toward the rocker arm shaft 7. The valve bridge 11 of the engine can be specifically located below the piston 4. A valve pin 13 can be fixed on the brake valve 12. The valve pin 13 is movably installed on the valve bridge 11 and can protrude upward from the upper surface of the valve bridge 11. When the piston 4 moves, the brake valve 12 is driven to move by pushing the valve pin 13.

[0056] The structure in which the positive power cam 9 drives the valve bridge 11 to move through the positive power rocker arm 10 when the positive power cam 9 rotates is a conventional technology. For example, when the positive power cam 9 rotates to its base circle and cooperates with the positive power rocker arm 10, the positive power rocker arm 10 and the valve bridge 11 do not move. In the process of the positive power cam 9 rotating to the positive power lift, the positive power lift drives the valve bridge 11 to move through the rotation of the positive power rocker arm 10 installed on the rocker arm shaft 7, and at the same time opens the non-braking valve 14 and the braking valve 12 on the valve bridge 11, completing the normal valve positive power lift.

[0057] The locking elastic element 3-2 pushes the locking block 3-1 to move until the locking block 3-1 cooperates with the limiting swing structure 7-1 of the rocker shaft 7, and the braking rocker arm 2 is locked on the rocker shaft 7 by the locking block 3-1;

[0058] The oil supply circuit 7-2 supplies oil, and the oil in the oil supply circuit 7-2 pushes the locking block 3-1, so that the locking block 3-1 overcomes the elastic force of the locking elastic element 3-2 and leaves the limiting swing structure 7-1 to unlock the brake rocker arm 2, and the oil in the oil supply circuit 7-2 enters the piston hole 2-5 through the brake oil circuit 2-2 to push the piston 4 to extend toward the brake valve 12. When the cam follower unit 2-1 contacts the brake cam 1, the rotating brake cam 1 slides or rolls with the cam follower unit 2-1 to drive the brake rocker arm 2 to rotate, and the piston 4 rotates with the brake rocker arm 2 to provide power for the engine's brake valve 12 to move relative to the valve bridge 11.

[0059] In the present embodiment, the self-unlocking locking unit 3 locks the brake rocker arm 2 mounted on the rocker shaft 7 through the locking block 3-1 when the engine is working, so as to fix the brake rocker arm 2, thereby avoiding the noise and wear caused by the easy swing of the brake rocker arm 2 when the engine is working. Moreover, when the engine is braking, the oil supply line 7-2 is used to supply oil to the brake oil line 2-2 to extend the piston 4. The locking block 3-1 will be pushed by the oil in the oil supply line 7-2 to displace and automatically unlock the brake rocker arm 2, thereby restoring the rotatable characteristics of the brake rocker arm 2, so that the brake cam 1 can drive the brake valve 12 to complete the brake lift through the brake rocker arm 2. The whole process does not require additional control operations and is simple to control.

[0060] In order to better understand the engine-specific hydraulic lost rocker arm brake in this embodiment, it is further explained and illustrated below;

[0061] In some examples, the brake rocker arm 2 further has a pressure relief oil circuit 2-3 connected to the brake oil circuit 2-2, and the oil drain port 2-31 of the pressure relief oil circuit 2-3 extends to the inner wall of the sliding hole 2-6;

[0062] When the brake rocker arm 2 is locked on the rocker arm shaft 7 by the locking block 3-1, the locking block 3-1 blocks the oil supply path 7-2, so that the oil supply path 7-2 is not connected with the brake oil path 2-2, and the locking block 3-1 is away from the oil drain port 2-31, so that the oil drain port 2-31 is opened; after the oil drain port 2-31 is opened, the oil in the brake oil path 2-2 can flow out from the oil drain port 2-31, and the piston 4 is no longer affected by the hydraulic pressure in the brake oil path 2-2, so that the piston 4 can retract and separate from the valve pin 13, thereby realizing automatic oil drain;

[0063] When the locking block 3-1 unlocks the brake rocker arm 2, the locking block 3-1 releases the blockage on the oil supply path 7-2, so that the oil supply path 7-2 is connected to the brake oil path 2-2, and the locking block 3-1 moves to the oil drain port 2-31 to block the oil drain port 2-31; after the pressure relief oil path 2-3 is blocked, the brake oil path 2-2 will be locked (the brake oil path 2-2 maintains pressure), and the oil in the brake oil path 2-2 will stop the piston 4 from retracting and become a rigid body. In this way, the piston 4 rotating with the brake rocker arm 2 can rigidly push the valve pin 13 to drive the brake valve 12 to move.

[0064] The oil drain port 2-31 is extended to the inner wall of the sliding hole 2-6 and matched with the movable design of the locking block 3-1, so that the locking block 3-1 can also be used to realize the self-pressure maintaining or oil draining function of the brake oil circuit 2-2. The brake oil circuit 2-2 does not need additional pressure maintaining or oil draining operations, thereby simplifying the structure.

[0065] In some examples, the limiting swing structure 7-1 is a locking groove 7-11 opened on the rocker shaft 7, and a locking protrusion 3-11 extends from one end of the locking block 3-1 close to the rocker shaft 7. When the locking protrusion 3-11 is embedded in the locking groove 7-11, the braking rocker arm 2 is locked on the rocker shaft 7 by the locking block 3-1; the design of embedding the locking protrusion 3-11 in the locking groove 7-11 can effectively improve the locking effect of the braking rocker arm 2; it is worth noting that the limiting swing structure 7-1 can also be a plane, arc surface or spherical surface, etc. set on the rocker shaft 7.

[0066] In some examples, when the locking protrusion 3-11 is inserted into the locking groove 7-11, a gap 3-3 is left between the locking protrusion 3-11 and the locking groove 7-11 on one side or both sides in the rotation direction of the brake rocker arm 2, which facilitates the locking protrusion 3-11 to smoothly enter the locking groove 7-11;

[0067] The locking protrusion 3-11 has a positioning portion 3-111 at one end close to the locking groove 7-11, and the bottom of the locking groove 7-11 has a positioning surface 7-111 matching the positioning portion 3-111. The cross-sectional area of ​​the positioning portion 3-111 gradually decreases along the direction from the locking block 3-1 to the rocker shaft 7. The positioning portion 3-111 can be, but is not limited to, a spherical crown type, a hemispherical type, a V-type, an arc type or a conical type. Taking the positioning portion 3-111 as a spherical crown type as an example, the positioning surface 7-111 matching the positioning portion 3-111 is also a spherical crown type; the cross-sections of the locking block 3-1 and the locking protrusion 3-11 can be of any shape, and this embodiment does not limit this. Specifically, the cross-sections of the locking block 3-1 and the locking protrusion 3-11 are both circular, the outer diameter of the locking block 3-1 can be larger than the outer diameter of the locking protrusion 3-11, and the outer diameter of the locking protrusion 3-11 is greater than or equal to the outer diameter of the positioning portion 3-111;

[0068] When the positioning portion 3-111 is embedded in the positioning surface 7-111 and the locking protrusion 3-11 is introduced and positioned in the locking groove 7-11, the brake rocker arm 2 is locked on the rocker arm shaft 7 by the locking block 3-1.

[0069] When the brake is closed, the positioning function between the positioning portion 3-111 and the positioning surface 7-111 is utilized, and the positioning portion 3-111 presses the positioning surface 7-111 under the action of the locking elastic element 3-2, so as to achieve accurate resetting of the brake rocker arm 2 and ensure the consistency of the position of the brake rocker arm 2 when it is fixed; and Figure 7 As shown, before the locking block 3-1 is inserted into the locking groove 7-11 and is not locked completely, the smaller positioning portion 3-111 at the lower end of the locking block 3-1 is inserted into the locking groove 7-1 in advance, which can prevent the rocker arm 2 from swinging excessively and help the rocker arm 2 to achieve quick locking.

[0070] In some examples, the outlet 7-21 of the oil supply circuit 7-2 is located at the bottom of the locking groove 7-11, and the oil supply circuit 7-2 is connected to the brake oil circuit 2-2 through the locking groove 7-11. When the locking protrusion 3-11 abuts against the bottom of the locking groove 7-11, the outlet 7-21 of the oil supply circuit 7-2 is blocked; thereby, on the one hand, the locking block 3-1 will be displaced in advance by the oil in the oil supply circuit 7-2 to unlock the brake rocker arm 2, thereby restoring the rotatable property of the brake rocker arm 2 to prevent the oil from directly entering the brake oil circuit 2-2; on the other hand, the blocking of the outlet 7-21 of the oil supply circuit 7-2 by the locking block 3-1 reduces oil leakage.

[0071] In some examples, one end of the sliding hole 2-6 extends to the outer wall surface of the brake rocker arm 2, and the other end extends to the inner wall surface of the shaft hole 2-4. The oil in the pressure relief oil circuit 2-3 flows into the sliding hole 2-6 through the oil drain port 2-31, and then flows out from the sliding hole 2-6 to one end of the outer wall surface of the brake rocker arm 2 to drain the oil. The end of the locking elastic element 3-2 away from the rocker arm shaft 7 presses against the brake rocker arm 2, and the end of the locking elastic element 3-2 close to the rocker arm shaft 7 presses against the locking block 3-1; the locking elastic element Component 3-2 may be a spring, and a spring cavity 3-12 may be provided at one end of the locking block 3-1 away from the rocker shaft 7. A portion of the locking elastic element 3-2 is located in the spring cavity 3-12, and one end of the locking elastic element 3-2 close to the rocker shaft 7 abuts against the bottom of the spring cavity 3-12. A first limiting component 3-4 is provided at one end of the sliding hole 2-6 away from the rocker shaft 7, and one end of the locking elastic element 3-2 away from the rocker shaft 7 abuts against the first limiting component 3-4. The first limiting component 3-4 may be a spring retaining ring.

[0072] In some examples, a one-way component 8 is provided on the oil supply circuit 7-2 and / or the brake oil circuit 2-2. The one-way component 8 can adopt any one-way valve in the prior art. The one-way component 8 is used to allow oil to flow from the oil supply circuit 7-2 to the brake oil circuit 2-2, but prevent oil from flowing from the brake oil circuit 2-2 to the oil supply circuit 7-2; when the piston 4 pushes the brake valve 12, the one-way component 8 prevents oil from flowing from the brake oil circuit 2-2 to the oil supply circuit 7-2, and the oil in the brake oil circuit 2-2 can be regarded as a rigid body, thereby preventing the piston 4 from retracting during power transmission.

[0073] In some examples, the one-way component 8 is disposed on the brake oil circuit 2 - 2 ;

[0074] The one-way component 8 includes a fastener, a valve elastic element 8-2 and a valve core 8-1. The valve elastic element 8-2 can be a spring, and the valve core 8-1 can be spherical. The brake oil circuit 2-2 has at least one section of a variable diameter hole 2-21 along its extension trajectory. The variable diameter hole 2-21 has a fine hole section 2-212 and a coarse hole section 2-211 that are connected to each other. The cross-sectional area of ​​the coarse hole section 2-211 is larger than the cross-sectional area of ​​the fine hole section 2-212. A step surface is formed between the fine hole section 2-212 and the coarse hole section 2-211. The fastener is detachably fixed on the brake rocker arm 2 and blocks one end of the coarse hole section 2-211 away from the fine hole section 2-212. The fastener can be specifically threadedly connected to the brake rocker arm 2.

[0075] The valve elastic element 8-2 and the valve core 8-1 are located in the coarse hole section 2-211, one end of the valve elastic element 8-2 abuts against the fastener or the brake rocker arm 2, and the other end abuts against the valve core 8-1, and the valve core 8-1 abuts against the step surface to block the connection between the fine hole section 2-212 and the coarse hole section 2-211;

[0076] When the oil supply circuit 7-2 supplies oil, the valve core 8-1 is pushed by the oil, the valve elastic element 8-2 is compressed, and the oil flows through the connection between the fine hole section 2-212 and the coarse hole section 2-211 to continue to flow to the brake oil circuit 2-2 and the piston hole 2-5; when the piston 4 pushes the brake valve 12, the valve core 8-1 presses against the step surface again to block the connection between the fine hole section 2-212 and the coarse hole section 2-211, and the locked brake oil circuit 2-2 stops the piston 4 from retracting and becomes a rigid body.

[0077] In some examples, a brake elastic element 5 for moving the piston 4 away from the brake valve 12 is provided on the brake rocker arm 2, and the brake elastic element 5 may be a spring;

[0078] When the oil in the brake oil circuit 2-2 causes the piston 4 to overcome the elastic force of the brake elastic element 5, the oil in the brake oil circuit 2-2 pushes the piston 4 to extend toward the brake valve 12 to the open position; when the pressure relief oil circuit 2-3 is drained, the brake elastic element 5 drives the piston 4 to retract; through the setting of the brake elastic element 5, after the brake oil circuit 2-2 is drained, the brake elastic element 5 can automatically drive the piston 4 to retract through the elastic force.

[0079] Specifically, the piston hole 2-5 is arranged on the brake rocker arm 2 and opens downward, the piston 4 is coaxially slidably installed in the piston hole 2-5, and an adjusting bolt 15 can also be arranged between the piston 4 and the piston hole 2-5 to adjust the installation position of the piston 4 on the brake rocker arm 2. The piston 4 has an inner hole 41 opening upward, and the lower end of the adjusting bolt 15 extends into the inner hole 41 of the piston 4 and abuts against the lower end of the adjusting bolt 15. The upper end of the braking elastic element 5 abuts against the second limiting member 6 at the upper end of the inner hole 41 of the piston 4. The second limiting member 6 can be a spring retaining ring, so that the piston 4 can move upward under the action of the braking elastic element 5, that is, drive the piston 4 to retract.

[0080] In some examples, when the brake rocker arm 2 is locked on the rocker arm shaft 7 by the locking block 3-1, the brake cam 1 is separated from the cam follower unit 2-1, so that the brake cam 1 does not contact the cam follower unit 2-1 during rotation; to avoid wear between the brake cam 1 and the cam follower unit 2-1 and increase the service life.

[0081] In some examples, when the positive power rocker arm 10 of the engine does not drive the valve bridge 11 to move, and the oil supply circuit 7-2 supplies oil to unlock the brake rocker arm 2, when the brake cam 1 rotates to the point where the base circle 1-1 is directly opposite to the cam follower unit 2-1, the oil in the brake oil circuit 2-2 pushes the piston 4 to extend to abut the brake valve 12, thereby forcing the brake rocker arm 2 to rotate and causing the cam follower unit 2-1 to contact the base circle 1-1; when the brake cam 1 rotates to the point where the brake lift boss 1-2 slides or rolls with the cam follower unit 2-1, the brake lift boss 1-2 drives the brake rocker arm 2 to rotate, and the piston 4 rotates with the brake rocker arm 2 to provide power for the engine's brake valve 12 to move relative to the valve bridge 11.

[0082] In some examples, an engine includes the engine-specific hydraulic lost arm brake described above.

[0083] The working principle of the engine-specific hydraulic lost rocker arm brake of the above embodiment is:

[0084] 1) The solenoid valve of the engine is closed, and the oil supply circuit 7-2 stops supplying oil: there is no oil pressure in the brake oil circuit 2-2, and the locking elastic element 3-2 pushes the locking block 3-1 down to the locking groove 7-11. The positioning portion 3-111 of the locking block 3-1 abuts against and embeds into the positioning surface 7-111 of the rocker shaft 7. The outlet 7-21 of the oil supply circuit 7-2 is blocked by the locking block 3-1, and the oil drain port 2-31 is opened, that is, the locking block 3-1 is in the closed position, and the brake rocker 2 is locked on the rocker shaft 7 by the locking block 3-1 and remains stationary. The brake cam 1 is separated from the cam follower unit 2-1, and the brake elastic element 5 retracts the piston 4 to the closed position through elastic force;

[0085] During the rotation of the brake cam 1 and the positive power cam 9 along with the camshaft 16 of the engine, the lift of the brake cam 1 will not be transmitted to the brake valve 12 through the brake rocker arm 2; during the rotation of the positive power cam 9 to the positive power lift, the positive power lift drives the valve bridge 11 to move through the rotation of the positive power rocker arm 10, and simultaneously opens the non-brake valve 14 and the brake valve 12, completing the normal valve positive power lift.

[0086] 2) The solenoid valve of the engine is opened, and the oil supply circuit 7-2 supplies oil. The oil pushes the locking block 3-1 in advance until the locking block 3-1 is positioned to block the oil drain port 2-31, that is, the locking block 3-1 reaches the open position, the brake rocker arm 2 is unlocked, and after the oil enters the locking groove 7-11, it will flow to the brake oil circuit 2-2, the valve core 8-1 of the one-way component 8 is in the open position, and then the oil in the brake oil circuit 2-2 flows into the piston hole 2-5, and the oil in the piston hole 2-5 causes the piston 4 to overcome the elastic force of the brake elastic element 5 and extend;

[0087] When the positive power rocker arm 10 of the engine does not drive the valve bridge 11 to move, the brake cam 1 and the positive power cam 9 rotate with the camshaft 16 of the engine. When the brake cam 1 rotates to the point where the base circle 1-1 is directly opposite to the cam follower unit 2-1, the oil in the brake oil circuit 2-2 pushes the piston 4 to extend and abut the valve pin 13 of the brake valve 12, thereby forcing the brake rocker arm 2 to rotate and causing the cam follower unit 2-1 to contact the base circle 1-1; when the brake cam 1 rotates to the point where the brake lift boss 1-2 slides or rolls with the cam follower unit 2-1, the brake lift boss 1-2 drives the brake rocker arm 2 to rotate, and the piston 4 pushes the valve pin 13 downward as the brake rocker arm 2 rotates, causing the brake valve 12 where the valve pin 13 is located to move downward relative to the valve bridge 11, thereby pushing the brake valve 12 to complete the brake lift.

[0088] The above-mentioned ideal embodiments of the present invention are for inspiration. Through the above-mentioned description, relevant staff can make various changes and modifications without departing from the technical idea of ​​the present invention. The technical scope of the present invention is not limited to the contents of the specification, and its technical scope must be determined according to the scope of the claims.

Claims

1. A hydraulic loss-type rocker arm brake for an engine, characterized in that: include: A brake cam (1) comprising a base circle portion (1-1) and a brake lift boss (1-2) protruding from the base circle portion (1-1); A brake rocker arm (2) comprising a cam follower unit (2-1), a brake oil circuit (2-2), an axial hole (2-4) and a piston hole (2-5); a piston (4) is slidably mounted in the piston hole (2-5); the axial hole (2-4) of the brake rocker arm (2) is sleeved on a rocker arm shaft (7) of an engine; the rocker arm shaft (7) is located between the cam follower unit (2-1) and the piston (4); and the brake oil circuit (2-2) is in communication with the piston hole (2-5); and a self-unlocking locking unit (3), comprising a locking block (3-1) and a locking elastic element (3-2), wherein the brake rocker arm (2) has a sliding hole (2-6), the locking block (3-1) is slidably mounted in the sliding hole (2-6), and the locking elastic element (3-2) is used to push the locking block (3-1) to move toward the rocker arm shaft (7); When the locking elastic element (3-2) pushes the locking block (3-1) to move until the locking block (3-1) cooperates with the swing limiting structure (7-1) of the rocker shaft (7), the braking rocker arm (2) is locked on the rocker shaft (7) by the locking block (3-1); The oil supply path (7-2) supplies oil, and the oil in the oil supply path (7-2) pushes the locking block (3-1), so that the locking block (3-1) overcomes the elastic force of the locking elastic element (3-2) and leaves the swing limiting structure (7-1), thereby unlocking the brake rocker arm (2), and the oil in the oil supply path (7-2) enters the piston hole (2-5) through the brake oil path (2-2), thereby pushing the piston (4) to extend in the direction of the brake valve (12), so that when the cam follower unit (2-1) contacts the brake cam (1), the rotating brake cam (1) and the cam follower unit (2-1) slide or roll to drive the brake rocker arm (2) to rotate, and the piston (4) rotates with the brake rocker arm (2) to provide power for the engine's brake valve (12) to move relative to the valve bridge (11); The brake rocker arm (2) further comprises a pressure relief oil circuit (2-3) connected to the brake oil circuit (2-2), and an oil drain port (2-31) of the pressure relief oil circuit (2-3) extends to the inner wall of the sliding hole (2-6); When the brake rocker arm (2) is locked on the rocker arm shaft (7) by the locking block (3-1), the locking block (3-1) blocks the oil supply path (7-2), so that the oil supply path (7-2) is disconnected from the brake oil path (2-2), and the locking block (3-1) is away from the oil drain port (2-31), so that the oil drain port (2-31) is open; When the locking block (3-1) unlocks the brake rocker arm (2), the locking block (3-1) releases the blockage of the oil supply path (7-2), allowing the oil supply path (7-2) to communicate with the brake oil path (2-2), and the locking block (3-1) moves to the oil drain port (2-31) to block the oil drain port (2-31).

2. The engine-specific hydraulic lost rocker arm brake according to claim 1, characterized in that: The swing limiting structure (7-1) is a locking groove (7-11) formed on the rocker shaft (7); a locking protrusion (3-11) extends from one end of the locking block (3-1) close to the rocker shaft (7); when the locking protrusion (3-11) is embedded in the locking groove (7-11), the brake rocker arm (2) is locked on the rocker shaft (7) by the locking block (3-1).

3. The engine-specific hydraulic lost rocker arm brake according to claim 2, characterized in that: When the locking protrusion (3-11) is embedded in the locking groove (7-11), a gap (3-3) is left between the locking protrusion (3-11) and the locking groove (7-11) on one side or both sides in the rotation direction of the braking rocker arm (2); One end of the locking protrusion (3-11) close to the locking groove (7-11) has a positioning portion (3-111), the bottom of the locking groove (7-11) has a positioning surface (7-111) matching the positioning portion (3-111), and the cross-sectional area of ​​the positioning portion (3-111) gradually decreases along the direction from the locking block (3-1) to the rocker arm shaft (7); When the positioning portion (3-111) is embedded in the positioning surface (7-111) and the locking protrusion (3-11) is guided and positioned in the locking groove (7-11), the brake rocker arm (2) is locked on the rocker arm shaft (7) by the locking block (3-1).

4. The engine-specific hydraulic lost rocker arm brake according to claim 3, characterized in that: The positioning portion (3-111) is in a spherical cap shape, a hemispherical shape, a V shape, an arc shape or a cone shape.

5. The engine-specific hydraulic lost rocker arm brake according to claim 3, characterized in that: The outlet (7-21) of the oil supply path (7-2) is located at the bottom of the locking groove (7-11); the oil supply path (7-2) is connected to the brake oil path (2-2) through the locking groove (7-11); and the locking protrusion (3-11) blocks the outlet (7-21) of the oil supply path (7-2) when it abuts against the bottom of the locking groove (7-11).

6. The engine-specific hydraulic lost rocker arm brake according to claim 1, characterized in that: One end of the sliding hole (2-6) extends to the outer wall surface of the brake rocker arm (2), and the other end extends to the inner wall surface of the shaft hole (2-4); one end of the locking elastic element (3-2) away from the rocker arm shaft (7) abuts against the brake rocker arm (2), and one end of the locking elastic element (3-2) close to the rocker arm shaft (7) abuts against the locking block (3-1).

7. The engine-specific hydraulic lost rocker arm brake according to claim 1, characterized in that: A one-way component (8) is provided on the oil supply circuit (7-2) or / and the brake oil circuit (2-2), and the one-way component (8) is used to allow oil to flow from the oil supply circuit (7-2) to the brake oil circuit (2-2), but prevent oil from flowing from the brake oil circuit (2-2) to the oil supply circuit (7-2).

8. The engine-specific hydraulic lost rocker arm brake according to claim 7, characterized in that: The one-way component (8) is arranged on the brake oil circuit (2-2); The one-way component (8) comprises a fastener, a valve elastic element (8-2) and a valve core (8-1); the brake oil circuit (2-2) has at least one section of a variable diameter hole (2-21) along its extension trajectory; the variable diameter hole (2-21) has a fine hole section (2-212) and a coarse hole section (2-211) that are connected to each other; the cross-sectional area of ​​the coarse hole section (2-211) is larger than the cross-sectional area of ​​the fine hole section (2-212); a step surface is formed between the fine hole section (2-212) and the coarse hole section (2-211); the fastener is detachably fixed to the brake rocker arm (2) and blocks an end of the coarse hole section (2-211) away from the fine hole section (2-212); The valve elastic element (8-2) and the valve core (8-1) are located in the coarse hole section (2-211); one end of the valve elastic element (8-2) abuts against the fastener or the brake rocker arm (2), and the other end abuts against the valve core (8-1); the valve core (8-1) abuts against the step surface to block the connection between the fine hole section (2-212) and the coarse hole section (2-211).

9. The engine-specific hydraulic lost rocker arm brake according to claim 1, characterized in that: The brake rocker arm (2) is provided with a brake elastic element (5) for moving the piston (4) in a direction away from the brake valve (12); When the oil in the brake oil circuit (2-2) causes the piston (4) to overcome the elastic force of the brake elastic element (5), the oil in the brake oil circuit (2-2) pushes the piston (4) to extend toward the brake valve (12) to an open position; when the pressure relief oil circuit (2-3) releases oil, the brake elastic element (5) drives the piston (4) to retract.

10. The engine-specific hydraulic lost rocker arm brake according to claim 9, characterized in that: When the braking rocker arm (2) is locked on the rocker arm shaft (7) by the locking block (3-1), the braking cam (1) is separated from the cam follower unit (2-1), so that the braking cam (1) does not contact the cam follower unit (2-1) during the rotation process.

11. The engine-specific hydraulic lost rocker arm brake according to claim 10, characterized in that: When the positive power rocker arm (10) of the engine does not drive the valve bridge (11) to move, and the oil supply path (7-2) supplies oil to unlock the brake rocker arm (2), when the brake cam (1) rotates to the point where the base circle (1-1) is directly opposite to the cam follower unit (2-1), the oil in the brake oil path (2-2) pushes the piston (4) to extend to abut against the brake valve (12), thereby forcing the brake rocker arm (2) to rotate and causing the cam follower unit (2-1) to contact the base circle (1-1); when the brake cam (1) rotates to the point where the brake lift boss (1-2) and the cam follower unit (2-1) slide or roll together, the brake lift boss (1-2) drives the brake rocker arm (2) to rotate, and the piston (4) rotates with the brake rocker arm (2) to provide power for the engine's brake valve (12) to move relative to the valve bridge (11).

12. An engine, characterized in that: It comprises the engine-specific hydraulic lost arm brake as described in any one of claims 1-11.

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