Engine braking device having return and limit functions, and engine
By designing an engine braking device with return and limit functions, and utilizing the cooperation of the limit protrusion and concave part, the problem of the device being too large and colliding with the engine cover was solved, resulting in a more compact structure and better braking effect.
Patent Information
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- ZHEJIANG LIMING INTELLIGENT MFG CO LTD
- Filing Date
- 2025-04-03
- Publication Date
- 2026-06-18
AI Technical Summary
The existing engine braking system is too large in the vertical direction, which may cause it to collide with the engine cover and affect the braking effect.
An engine braking device with return and limit functions was designed. Through the combination structure of camshaft, braking rocker arm, rocker arm shaft, rocker arm support, return spring bracket and sliding unit, the vertical dimension of the device is reduced by the convex-concave fit of the limit protrusion and the limit recess, and the swing amplitude of the rocker arm is controlled during the braking phase.
It effectively reduces the vertical dimension of the engine braking device, reduces frictional power consumption, improves braking effect, and ensures that the rollers and cams do not contact each other when the device is working normally, thus enhancing the compactness and reliability of the structure.
Smart Images
Figure CN2025087232_18062026_PF_FP_ABST
Abstract
Description
An engine braking device and engine with return and limit functions Technical Field
[0001] This invention belongs to the field of automotive parts technology, and relates to an engine braking device, particularly an engine braking device and engine with return and limit functions. Background Technology
[0002] Engine braking technology refers to the braking effect on a vehicle caused by the driver releasing the accelerator pedal and clutch during driving. This effect utilizes the compression resistance generated during the engine's compression stroke, along with intake and exhaust resistance and friction, to apply braking force to the drive wheels. Engine braking effectively reduces the frequency of use of the service brakes. When driving down long slopes or on steep roads such as rugged mountain roads, using engine braking can prevent the brake pads from overheating due to prolonged brake use, which could lead to a decrease in braking force or even complete loss of effectiveness.
[0003] Patent application (CN202110941484.X) discloses an energy-saving and consumption-reducing engine braking device, including a movable unit and a control mechanism. The movable unit is movably disposed at the rear end of the auxiliary rocker arm and corresponds to the auxiliary cam. The control mechanism can drive the movable unit to move, so that the movable unit has a first position that is in contact with the auxiliary cam and a second position that is separated from the auxiliary cam.
[0004] Although the aforementioned engine braking device achieves energy saving and consumption reduction, the entire engine braking device is relatively large in the vertical direction. After installation, there is a possibility of collision with the engine cover, which may affect the engine braking effect. Summary of the Invention
[0005] The purpose of this invention is to address the aforementioned problems in existing technologies by proposing an engine braking device that can effectively reduce vertical dimensions while ensuring braking performance.
[0006] The objective of this invention can be achieved through the following technical solution: an engine braking device with return and limit functions, comprising:
[0007] A camshaft, including an auxiliary cam, and having a non-working surface and a working surface on the outer contour of the auxiliary cam, wherein the distance between the working surface and the center of the base circle of the auxiliary cam is greater than the distance between the non-working surface and the center of the base circle of the auxiliary cam;
[0008] A braking rocker arm and a rocker arm shaft are fitted through a shaft hole, and the braking rocker arm can reciprocate around the rocker arm shaft. The axial direction of the rocker arm shaft is parallel to the axial direction of the cam shaft. The side of the braking rocker arm extends horizontally to form an abutment platform. A limiting recess is provided on the outer surface of the rocker arm shaft, and the two sides of the limiting recess are a first abutment A surface and a first abutment B surface, respectively. The braking rocker arm is provided with a limiting protrusion that fits into the limiting recess. The two sides of the limiting protrusion are a second abutment A surface and a second abutment B surface, respectively. The relative distance between the second abutment A surface and the second abutment B surface is less than the relative distance between the first abutment A surface and the first abutment B surface.
[0009] The rocker arm support has two ends that mate with the camshaft and the rocker arm shaft respectively, and the end of the rocker arm support that mates with the camshaft shaft is provided with a first connecting part;
[0010] The return spring bracket is connected at one end to the first connecting part or to the second connecting part on the rocker arm shaft via a fastener. The horizontal height of the first connecting part and the horizontal height of the second connecting part are both higher than the horizontal height of the abutment platform, and the horizontal height of the return spring bracket is lower than the horizontal height of the upper surface of the brake rocker arm.
[0011] A sliding unit is slidably connected to one end of the brake rocker arm corresponding to the auxiliary cam, and the sliding unit is provided with a roller, wherein the axis of the roller is parallel to the axis of the camshaft.
[0012] The first elastic element is clamped at both ends between the other end of the return spring bracket and the abutment platform. The axis of the first elastic element is offset to one side of the line connecting the centers of the auxiliary cam and the roller, and the first elastic element is located between the roller and the rocker arm shaft.
[0013] When the engine is working normally, there is a gap between the working surface of the roller and the auxiliary cam, and the first abutting surface A and the second abutting surface A abut against each other, and the first elastic element is in an energy storage state.
[0014] When the engine brake is engaged, the roller contacts the outer contour of the auxiliary cam. As the working surface and non-working surface on the auxiliary cam alternately contact the roller, the brake rocker arm swings back and forth around the rocker arm axis, and the limiting protrusion swings back and forth within the limiting recess.
[0015] In the aforementioned engine braking device with return and limit functions, the position of the convex-concave fit between the limit recess and the limit protrusion is located on the right half of the rocker arm shaft, wherein the extension line of the axis of the limit protrusion passes through the center of the cross-section of the rocker arm shaft where the limit protrusion is located.
[0016] In the aforementioned engine braking device with return and limit functions, the limit recess is a limit hole, the limit protrusion is a limit pin screwed onto the brake rocker arm, and one end of the limit pin passes through the limit hole and extends into the rocker arm shaft. The diameter of the limit hole is larger than the diameter of the end of the limit pin that is inserted into the limit hole, and the first abutment A surface, the first abutment B surface, the second abutment A surface, and the second abutment B surface are arc-shaped.
[0017] In the aforementioned engine braking device with return and limit functions, the return spring bracket is plate-shaped, and one end of the return spring bracket is provided with a first mounting hole for inserting and engaging with a fastener and mounting the return spring bracket on the rocker arm support. The other end of the return spring bracket is provided with a boss, wherein the boss and the first elastic member form an interference fit, and the end of the first elastic member that engages with the boss abuts against the surface of the return spring bracket.
[0018] In the aforementioned engine braking device with return and limit functions, the return spring bracket is plate-shaped, and one end of the return spring bracket is provided with a first mounting hole for inserting and engaging with a fastener and mounting the return spring bracket on the rocker arm shaft. The other end of the return spring bracket is provided with a boss, wherein the boss and the first elastic member form an interference fit, and the end of the first elastic member that engages with the boss abuts against the surface of the return spring bracket.
[0019] In the aforementioned engine braking device with return and limit functions, the first connecting part includes a connecting post, and a connecting hole is provided in the connecting post. The first mounting hole on the return spring bracket is connected to the connecting hole by a fastener.
[0020] In the aforementioned engine braking device with return and limit functions, the second connecting part includes a first mounting plane formed by a downward recess on the rocker arm shaft facing the return spring bracket, and the horizontal height of the first mounting plane is higher than the horizontal height of the abutment platform. A second mounting hole connected to the return spring bracket is provided on the first mounting plane.
[0021] In the aforementioned engine braking device with return and limit functions, a first mounting plane is provided at both ends of the rocker arm shaft along its axial direction, and the first mounting planes at both ends of the rocker arm shaft are on the same horizontal plane.
[0022] In the aforementioned engine braking device with return and limit functions, a positioning part is provided on the abutment platform. The positioning part is nested and cooperates with the first elastic member. The radial degree of freedom of the first elastic member is limited by the positioning part. The positioning part is either a cavity or a positioning protrusion. When the positioning part is a cavity, one end of the first elastic member is embedded in the cavity and abuts against the bottom of the cavity. When the positioning part is a positioning protrusion, one end of the first elastic member is nested with the positioning protrusion and abuts against the surface of the abutment platform.
[0023] The present invention also provides an engine braking device with return and limit functions, comprising:
[0024] A camshaft, including an auxiliary cam, and having a non-working surface and a working surface on the outer contour of the auxiliary cam, wherein the distance between the working surface and the center of the base circle of the auxiliary cam is greater than the distance between the non-working surface and the center of the base circle of the auxiliary cam;
[0025] A braking rocker arm and a rocker arm shaft are fitted through a shaft hole, and the braking rocker arm can reciprocate around the rocker arm shaft. The axial direction of the rocker arm shaft is parallel to the axial direction of the cam shaft. The side of the braking rocker arm extends horizontally to form an abutment platform. A limiting recess is provided on the outer surface of the rocker arm shaft, and the two sides of the limiting recess are a first abutment A surface and a first abutment B surface, respectively. The braking rocker arm is provided with a limiting protrusion that fits into the limiting recess. The two sides of the limiting protrusion are a second abutment A surface and a second abutment B surface, respectively. The relative distance between the second abutment A surface and the second abutment B surface is less than the relative distance between the first abutment A surface and the first abutment B surface.
[0026] The rocker arm support has two ends that mate with the camshaft and the rocker arm shaft respectively, and the end of the rocker arm support that mates with the camshaft shaft is provided with a first connecting part;
[0027] The second elastic element has one end connected to the first connecting part by a fastener, or connected to the second connecting part on the rocker arm shaft. The horizontal height of the first connecting part and the horizontal height of the second connecting part are both lower than the horizontal height of the abutting platform, and the horizontal height of the end of the second elastic element that abuts the abutting platform is lower than the horizontal height of the upper surface of the braking rocker arm.
[0028] A sliding unit is slidably connected to one end of the brake rocker arm corresponding to the auxiliary cam, and the sliding unit is provided with a roller, wherein the axis of the roller is parallel to the axis of the camshaft.
[0029] When the engine is working normally, there is a gap between the roller and the working surface of the auxiliary cam, and the first abutting surface A and the second abutting surface A abut against each other, and the second elastic element is in a deformed state.
[0030] When the engine brake is engaged, the roller contacts the outer contour of the auxiliary cam. As the working surface and non-working surface on the auxiliary cam alternately contact the roller, the brake rocker arm swings back and forth around the rocker arm axis, and the limiting protrusion swings back and forth within the limiting recess.
[0031] In the aforementioned engine braking device with return and limit functions, the second elastic element is arranged in a Z-shaped plate shape, and the two ends of the second elastic element are the first connecting end and the second connecting end, respectively. The first connecting end forms surface-to-surface contact with the rocker arm shaft and is connected and fixed by fasteners, while the second connecting end forms surface-to-surface contact with the abutment platform.
[0032] In the aforementioned engine braking device with return and limit functions, a positioning protrusion or a positioning recess is provided on the abutment platform, and a corresponding positioning recess or positioning protrusion is provided on the second connecting end of the second elastic member. The relative sliding between the abutment platform and the second connecting end of the second elastic member is limited by the convex-concave fit between the positioning protrusion and the positioning recess.
[0033] In the aforementioned engine braking device with return and limit functions, the first connecting part includes a connecting post, and a connecting hole is provided in the connecting post. The third mounting hole on the second elastic member is connected to the connecting hole by a fastener.
[0034] In the aforementioned engine braking device with return and limit functions, the second connecting part includes a second mounting plane formed by a downward recess on the rocker arm shaft facing the second elastic member, and the horizontal height of the second mounting plane is lower than the horizontal height of the abutment platform. A fourth mounting hole connected to the second elastic member is provided on the second mounting plane.
[0035] In the aforementioned engine braking device with return and limit functions, a second mounting plane is provided at both ends of the rocker arm shaft along its axial direction, and the second mounting planes at both ends of the rocker arm shaft are on the same horizontal plane.
[0036] The present invention also provides an engine, including the aforementioned engine braking device with return and limit functions.
[0037] Compared with the prior art, the beneficial effects of the present invention are as follows:
[0038] (1) The engine braking device with return and limit functions provided by the present invention reduces the vertical dimension of the entire engine braking device, making the structure more compact. In addition, through the convex-concave fit between the limit protrusion and the limit recess, on the one hand, it ensures that the roller and the auxiliary cam do not contact each other when the engine is working normally, reducing friction work and reducing engine fuel consumption. On the other hand, it can control the amplitude of the reciprocating swing of the brake rocker arm when the engine is in the braking stage, thereby improving the braking effect.
[0039] (2) The positioning part is set on the contact platform to ensure that the elastic element always moves along the axis of the elastic element during the stretching or compression process, without twisting or deviating.
[0040] (3) The elastic element is set as a plate structure so that the elastic element is in contact with both the surface of the abutting platform and the surface of the second mounting plane. By increasing the contact area, the firmness of the connection of the elastic element and the reliability of its use are improved. Attached Figure Description
[0041] Figure 1 is a schematic diagram of the structure of an engine braking device with return and limit functions according to the present invention.
[0042] Figure 2 is a schematic diagram of the structure of an engine braking device with return and limit functions of the present invention when the engine is working normally.
[0043] Figure 3 is a schematic diagram of the structure of an engine braking device with return and limit functions in the engine braking state according to the present invention.
[0044] Figure 4 is an enlarged view of part A in Figure 2.
[0045] Figure 5 is an enlarged view of part B in Figure 3.
[0046] Figure 6 is a schematic diagram of the braking rocker arm in a preferred embodiment of the present invention.
[0047] Figure 7 is a schematic diagram of the rocker arm shaft in a preferred embodiment of the present invention.
[0048] Figure 8 is a schematic diagram of the return spring bracket in a preferred embodiment of the present invention.
[0049] Figure 9 is a cross-sectional view of the return spring bracket and the first elastic element in a preferred embodiment of the present invention.
[0050] Figure 10 is a schematic diagram of another embodiment of an engine braking device with return and limit functions according to the present invention.
[0051] Figure 11 is a schematic diagram of the rocker arm shaft shown in Figure 10.
[0052] Figure 12 is a schematic diagram of the structure of the second elastic element shown in Figure 10.
[0053] In the picture,
[0054] 10. Camshaft; 11. Auxiliary cam; 111. Non-working surface; 112. Working surface;
[0055] 20. Brake rocker arm; 21. Abutment platform; 211. Positioning part; 22. Limiting protrusion; 221. Second abutment surface A; 222. Second abutment surface B;
[0056] 30. Rocker arm shaft; 31. Limiting recess; 311. First abutting surface A; 312. First abutting surface B; 32. Second connecting part; 321. First mounting plane; 322. Second mounting hole;
[0057] 40. Rocker arm support; 41. First connecting part; 411. Connecting column; 412. Connecting hole;
[0058] 50. Return spring bracket; 51. First mounting hole; 52. Boss;
[0059] 60. Sliding unit; 61. Roller;
[0060] 70. First elastic element;
[0061] 80. Second elastic element; 81. First connecting end; 82. Second connecting end; 83. Third mounting hole. Detailed Implementation
[0062] The following are specific embodiments of the present invention, which are described in conjunction with the accompanying drawings. However, the present invention is not limited to these embodiments.
[0063] It should be noted that all directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of the present invention are only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indication will also change accordingly. Example 1
[0064] As shown in Figures 1 to 9, the present invention provides an engine braking device with return and limit functions, comprising:
[0065] The camshaft 10 includes an auxiliary cam 11, and a non-working surface 111 and a working surface 112 are provided on the outer contour of the auxiliary cam 11, wherein the distance between the working surface 112 and the center of the base circle of the auxiliary cam 11 is greater than the distance between the non-working surface 111 and the center of the base circle of the auxiliary cam 11.
[0066] The braking rocker arm 20 and the rocker arm shaft 30 are connected by a shaft hole, and the braking rocker arm 20 can swing back and forth around the rocker arm shaft 30. The axial direction of the rocker arm shaft 30 is parallel to the axial direction of the cam shaft 10. The side of the braking rocker arm 20 extends horizontally to form an abutment platform 21. A limiting recess 31 is provided on the outer surface of the rocker arm shaft 30, and the two sides of the limiting recess 31 are a first abutment A surface 311 and a first abutment B surface 312, respectively. The braking rocker arm 20 is provided with a limiting protrusion 22 that cooperates with the limiting recess 31. The two sides of the limiting protrusion 22 are a second abutment A surface 221 and a second abutment B surface 222, respectively. The relative distance between the second abutment A surface 221 and the second abutment B surface 222 is less than the relative distance between the first abutment A surface 311 and the first abutment B surface 312.
[0067] The rocker arm support 40 has two ends that are respectively engaged with the shaft holes of the camshaft 10 and the rocker arm shaft 30, and a first connecting part 41 is provided on the end of the rocker arm support 40 that is engaged with the shaft hole of the camshaft 10.
[0068] The return spring bracket 50 is connected at one end to the first connecting part 41 by a fastener, or to the second connecting part 32 on the rocker arm shaft 30. The horizontal height of the first connecting part 41 and the horizontal height of the second connecting part 32 are both higher than the horizontal height of the abutment platform 21, and the horizontal height of the return spring bracket 50 is lower than the horizontal height of the upper surface of the brake rocker arm 20.
[0069] The sliding unit 60 is slidably connected to one end of the brake rocker arm 20 corresponding to the auxiliary cam 11, and the sliding unit 60 is provided with a roller 61, wherein the axial direction of the roller 61 is parallel to the axial direction of the camshaft 10.
[0070] The first elastic element 70 is clamped at both ends between the other end of the return spring bracket 50 and the abutment platform 21, and the extension and retraction direction of the first elastic element 70 is parallel to the line connecting the centers of the auxiliary cam 11 and the roller 61. The axis of the first elastic element 70 is offset to one side of the line connecting the centers of the auxiliary cam 11 and the roller 61, and the first elastic element 70 is located between the roller 61 and the rocker arm shaft 30.
[0071] When the engine is working normally, there is a gap between the roller 61 and the working surface 112 of the auxiliary cam 11, and the first abutting surface 311 and the second abutting surface 221 abut against each other, and the first elastic element 70 is in an energy storage state.
[0072] When the engine brake is engaged, the roller 61 contacts the outer contour of the auxiliary cam 11. As the working surface 112 and the non-working surface 111 on the auxiliary cam 11 alternately contact the roller 61, the brake rocker arm 20 swings back and forth around the rocker arm shaft 30, and the limiting protrusion 22 swings back and forth within the limiting recess 31.
[0073] The present invention provides an engine braking device with return and limit functions, which reduces the vertical dimension of the entire engine braking device, making the structure more compact. In addition, through the convex-concave fit between the limit protrusion 22 and the limit recess 31, it ensures that the roller 61 and the auxiliary cam 11 do not contact each other when the engine is working normally, reducing friction work and reducing engine fuel consumption. On the other hand, it can control the amplitude of the reciprocating swing of the brake rocker arm 20 when the engine is in the braking stage, thereby improving the braking effect.
[0074] Furthermore, the position of the concave-convex fit between the limiting recess 31 and the limiting protrusion 22 is located on the right half of the rocker arm shaft 30, wherein the extension line of the axis of the limiting protrusion 22 passes through the center of the cross-section of the rocker arm shaft 30 where the limiting protrusion 22 is located.
[0075] Preferably, the limiting recess 31 is a limiting hole, and the limiting protrusion 22 is a limiting pin screwed onto the braking rocker arm 20. One end of the limiting pin passes through the limiting hole and extends into the rocker arm shaft 30. The diameter of the limiting hole is larger than the diameter of the end of the limiting pin that is inserted into the limiting hole. The first abutting surface A 311, the first abutting surface B 312, the second abutting surface A 221, and the second abutting surface B 222 are arranged in an arc shape.
[0076] It is worth mentioning that when the engine is operating normally, the first abutting surface 311 and the second abutting surface 221 abut against each other. At this time, the first elastic element 70 is in an energy-storing state, and the roller 61 does not contact the working surface 112 on the auxiliary cam 11 under the action of the sliding unit 60. When the engine is in a braking state, the roller 61 extends under the action of the sliding unit 60 and contacts the outer contour of the auxiliary cam 11, releasing the abutment between the first abutting surface 311 and the second abutting surface 221. As the roller 61 alternately passes the auxiliary cam 11... The working surface 112 and non-working surface 111 on the upper part, the limiting protrusion 22 swings back and forth in the limiting recess 31, and during the reciprocating swing of the limiting protrusion 22, the first abutting surface A 311 and the second abutting surface A 221 do not contact each other, the first abutting surface B 312 and the second abutting surface B 222 do not contact each other. When the engine braking is completed and it returns to normal operation, the roller 61 retracts under the action of the sliding unit 60 and forms a gap with the working surface 112 of the auxiliary cam 11 again. At the same time, the first abutting surface A 311 and the second abutting surface A 221 abut again.
[0077] Preferably, the return spring bracket 50 is plate-shaped, and one end of the return spring bracket 50 is provided with a first mounting hole 51 for inserting and engaging with a fastener and mounting the return spring bracket 50 onto the rocker arm support 40. The other end of the return spring bracket 50 is provided with a boss 52, wherein the boss 52 and the first elastic member 70 form an interference fit, and the end of the first elastic member 70 that engages with the boss 52 abuts against the surface of the return spring bracket 50.
[0078] In this embodiment, the boss 52 on the return spring bracket 50 is generally formed by riveting. The boss 52 formed in this way is elastic and can tension the first elastic member 70, complete the interference connection between the return spring bracket 50 and the first elastic member 70, and ensure that the two do not separate, thereby improving the reliability of the connection between the two.
[0079] It is worth mentioning that one end of the first mounting hole 51 on the return spring bracket 50 can also be connected to the rocker arm shaft 30, and the horizontal height of the connection position between the return spring bracket 50 and the rocker arm shaft 30 is also higher than the horizontal height of the abutment platform 21.
[0080] Preferably, the first connecting part 41 includes a connecting post 411, and a connecting hole 412 is provided in the connecting post 411, wherein the first mounting hole 51 on the return spring bracket 50 and the connecting hole 412 are connected by fasteners.
[0081] Preferably, the second connecting part 32 includes a first mounting plane 321 formed by a downward recess on the rocker arm shaft 30 facing the return spring bracket 50, and the horizontal height of the first mounting plane 321 is higher than the horizontal height of the abutment platform 21. A second mounting hole 322 connected to the return spring bracket 50 is provided on the first mounting plane 321.
[0082] It is worth mentioning that when one end of the return spring bracket 50 is connected to the rocker arm shaft 30, the reason why a first mounting surface 321 for connecting the return spring bracket 50 is provided on the rocker arm shaft 30, and the first mounting surface 321 is formed by the downward concavity of the arc surface of the rocker arm shaft 30, is that this can control the position of the positioning return spring bracket 50 on the first mounting surface 321, avoid relative slippage between the two when they are connected, thereby improving the reliability of the connection between the two.
[0083] Furthermore, it is pointed out that both ends of the rocker arm shaft 30 along its axial direction are provided with a first mounting surface 321, and the first mounting surfaces 321 at both ends of the rocker arm shaft 30 are on the same horizontal plane.
[0084] In this embodiment, a first mounting surface 321 is provided at each end of the rocker arm shaft 30 to prevent foolproof installation of the rocker arm shaft 30. It is worth mentioning that a limiting recess 31 is also provided at each end of the rocker arm shaft 30, thus achieving a true "symmetrical arrangement" of the rocker arm shaft 30 and ensuring the efficiency of engine braking device assembly.
[0085] Preferably, the abutment platform 21 is provided with a positioning part 211, which is nested and cooperates with the first elastic member 70. The positioning part 211 limits the radial degree of freedom of the first elastic member 70. The positioning part 211 is either a cavity or a positioning protrusion. When the positioning part 211 is a cavity, one end of the first elastic member 70 is embedded in the cavity and abuts against the bottom of the cavity. When the positioning part 211 is a positioning protrusion, one end of the first elastic member 70 is nested with the positioning protrusion and abuts against the surface of the abutment platform 21.
[0086] It is worth mentioning that the positioning part 211 is provided on the abutment platform 21 to ensure that the first elastic member 70 always moves along the axis of the first elastic member 70 during the process of extension or compression, without twisting or deviating.
[0087] Furthermore, a positioning part 211 is provided on the abutment platform 21. To reduce assembly parts and improve assembly efficiency, it is best to directly integrate the positioning part 211 onto the abutment platform 21. Therefore, the positioning part 211 can be either a cavity or a positioning protrusion. A cavity refers to a cavity whose opening is flush with the upper surface of the abutment platform 21, and whose bottom is lower than the upper surface of the abutment platform 21. A positioning protrusion refers to a step whose bottom is flush with the upper surface of the abutment platform 21, and whose top is higher than the upper surface of the abutment platform 21. When the positioning part 211 is a cavity, the first elastic member 70 is inserted into the positioning part 211; when the positioning part 211 is a positioning protrusion, the positioning part 211 is inserted into the first elastic member 70.
[0088] Therefore, in order to increase the contact area between the positioning part 211 and the first elastic member 70, the positioning part 211 is generally set to be circular, and the first elastic member 70 here is a cylindrical spring, which is also generally set to be circular.
[0089] Furthermore, it is pointed out that the positioning part 211 is not limited to being integrally formed on the abutting platform 21, but can also be installed on the abutting platform 21 through a certain structure to achieve the effect of positioning the first elastic element 70. Example 2
[0090] As shown in Figures 1 to 12, the difference between this embodiment and Embodiment 1 is that the first elastic element 70 in Embodiment 1 is a cylindrical elastic element, while the second elastic element 80 in this embodiment is a plate-shaped elastic element. Therefore, in Embodiment 1, for the installation of the cylindrical elastic element, it is clearly stated that a return spring bracket 50 is added, and one end of the return spring bracket 50 is connected to the first connecting part 41 by a fastener, or connected to the second connecting part 32 on the rocker arm shaft 30. The horizontal height of the first connecting part 41 and the horizontal height of the second connecting part 32 are both higher than the horizontal height of the abutment platform 21, and the horizontal height of the return spring bracket 50 is lower than the horizontal height of the upper surface of the braking rocker arm 20.
[0091] In this embodiment, no return spring bracket 50 is provided. Therefore, regarding the installation of the plate-shaped elastic element, it is clearly stated that one end of the second elastic element 80 is connected to the first connecting part 41 by a fastener, or connected to the second connecting part 32 on the rocker arm shaft 30. The horizontal height of the first connecting part 41 and the horizontal height of the second connecting part 32 are both lower than the horizontal height of the abutting platform 21, and the horizontal height of the end of the second elastic element 80 that abuts the abutting platform 21 is lower than the horizontal height of the upper surface of the braking rocker arm 20.
[0092] It is worth mentioning that when the first elastic element 70 is a cylindrical second elastic element, the horizontal height of the first connecting part 41 and the second connecting part 32 is higher than the horizontal height of the abutting platform 21; when the second elastic element 80 is a plate-shaped elastic element, the horizontal height of the first connecting part 41 and the second connecting part 32 is lower than the horizontal height of the abutting platform 21.
[0093] Both the engine braking device in Embodiment 1 and the engine braking device in Embodiment 2 can reduce the overall vertical dimension of the engine braking device, making the structure more compact.
[0094] Furthermore, the second elastic member 80 is arranged in a Z-shaped plate shape, and the two ends of the second elastic member 80 are the first connecting end 81 and the second connecting end 82, respectively. The first connecting end 81 forms a surface-to-surface contact with the second mounting plane on the rocker arm shaft 30 and is connected and fixed by fasteners. The second connecting end 82 forms a surface-to-surface contact with the abutment platform 21. A fourth mounting hole is provided on the second mounting plane.
[0095] In this embodiment, the second elastic member 80 is configured as a plate-like structure, thereby increasing the contact area and improving the connection strength and reliability of the second elastic member 80, regardless of whether it is in contact with the surface of the abutment platform 21 or the surface of the second mounting plane.
[0096] Furthermore, the structure of the second mounting plane and the fourth mounting hole provided on the second mounting plane is the same as the structure of the first mounting plane 321 and the second mounting hole 322 provided on the first mounting plane 321, wherein the second elastic member 80 is provided with a third mounting hole 83 connected to the fourth mounting hole.
[0097] Furthermore, in addition to direct surface-to-surface contact, the abutting platform 21 and the second connecting end 82 of the second elastic member 80 can also have a positioning protrusion or a positioning recess on the abutting platform 21, and a corresponding positioning recess or positioning protrusion on the second connecting end 82 of the second elastic member 80. The relative sliding between the abutting platform 21 and the second connecting end 82 of the second elastic member 80 is limited by the convex-concave fit between the positioning protrusion and the positioning recess.
[0098] It is worth mentioning that the function of providing the positioning protrusion and positioning recess on the abutting platform 21 and the second elastic member 80 is the same as the function of providing the positioning part 211 in Embodiment 1, so it will not be described in detail here.
[0099] It should be noted that in this invention, the use of terms such as "first," "second," and "a" is for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified. The terms "connection," "fixed," etc., should be interpreted broadly. For example, "fixed" can mean a fixed connection, a detachable connection, or an integral part; it can mean a mechanical connection or an electrical connection; it can mean a direct connection or an indirect connection through an intermediate medium; it can mean the internal communication of two elements or the interaction between two elements, unless otherwise explicitly specified. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.
[0100] Furthermore, the technical solutions of the various embodiments of the present invention can be combined with each other, but only if they are feasible for those skilled in the art. If the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such combination of technical solutions does not exist and is not within the scope of protection claimed by the present invention.
[0101] The specific embodiments described herein are merely illustrative of the spirit of the invention. Those skilled in the art to which this invention pertains may make various modifications or additions to the described specific embodiments or use similar methods to substitute them, without departing from the spirit of the invention or exceeding the scope defined by the appended claims.
Claims
1. An engine braking device with return and limit functions, characterized in that, include: A camshaft, including an auxiliary cam, and having a non-working surface and a working surface on the outer contour of the auxiliary cam, wherein the distance between the working surface and the center of the base circle of the auxiliary cam is greater than the distance between the non-working surface and the center of the base circle of the auxiliary cam; A braking rocker arm and a rocker arm shaft are fitted through a shaft hole, and the braking rocker arm can reciprocate around the rocker arm shaft. The axial direction of the rocker arm shaft is parallel to the axial direction of the cam shaft. The side of the braking rocker arm extends horizontally to form an abutment platform. A limiting recess is provided on the outer surface of the rocker arm shaft, and the two sides of the limiting recess are a first abutment A surface and a first abutment B surface, respectively. The braking rocker arm is provided with a limiting protrusion that fits into the limiting recess. The two sides of the limiting protrusion are a second abutment A surface and a second abutment B surface, respectively. The relative distance between the second abutment A surface and the second abutment B surface is less than the relative distance between the first abutment A surface and the first abutment B surface. The rocker arm support has two ends that mate with the camshaft and the rocker arm shaft respectively, and the end of the rocker arm support that mates with the camshaft shaft is provided with a first connecting part; The return spring bracket is connected at one end to the first connecting part or to the second connecting part on the rocker arm shaft via a fastener. The horizontal height of the first connecting part and the horizontal height of the second connecting part are both higher than the horizontal height of the abutment platform, and the horizontal height of the return spring bracket is lower than the horizontal height of the upper surface of the brake rocker arm. A sliding unit is slidably connected to one end of the brake rocker arm corresponding to the auxiliary cam, and the sliding unit is provided with a roller, wherein the axis of the roller is parallel to the axis of the camshaft. The first elastic element is clamped at both ends between the other end of the return spring bracket and the abutment platform. The axis of the first elastic element is offset to one side of the line connecting the centers of the auxiliary cam and the roller, and the first elastic element is located between the roller and the rocker arm shaft. When the engine is working normally, there is a gap between the working surface of the roller and the auxiliary cam, and the first abutting surface A and the second abutting surface A abut against each other, and the first elastic element is in an energy storage state. When the engine brake is engaged, the roller contacts the outer contour of the auxiliary cam. As the working surface and non-working surface on the auxiliary cam alternately contact the roller, the brake rocker arm swings back and forth around the rocker arm axis, and the limiting protrusion swings back and forth within the limiting recess.
2. The engine braking device with return and limit functions according to claim 1, characterized in that, The position of the concave-convex fit between the limiting recess and the limiting protrusion is located on the right half of the rocker arm shaft, wherein the extension line of the axis of the limiting protrusion passes through the center of the cross-section of the rocker arm shaft where the limiting protrusion is located.
3. The engine braking device with return and limit functions according to claim 1, characterized in that, The limiting recess is a limiting hole, and the limiting protrusion is a limiting pin screwed onto the brake rocker arm. One end of the limiting pin passes through the limiting hole and extends into the rocker arm shaft. The diameter of the limiting hole is larger than the diameter of the end of the limiting pin that is inserted into the limiting hole. The first abutting surface A, the first abutting surface B, the second abutting surface A, and the second abutting surface B are arc-shaped.
4. The engine braking device with return and limit functions according to any one of claims 1 to 3, characterized in that, The return spring bracket is plate-shaped, and one end of the return spring bracket is provided with a first mounting hole for inserting and engaging with a fastener and mounting the return spring bracket on the rocker arm support. The other end of the return spring bracket is provided with a boss, wherein the boss and the first elastic member form an interference fit, and the end of the first elastic member that engages with the boss abuts against the surface of the return spring bracket.
5. The engine braking device with return and limit functions according to any one of claims 1-3, characterized in that, The return spring bracket is plate-shaped, and one end of the return spring bracket is provided with a first mounting hole for inserting and engaging with a fastener and mounting the return spring bracket on the rocker arm shaft. The other end of the return spring bracket is provided with a boss, wherein the boss and the first elastic member form an interference fit, and the end of the first elastic member that engages with the boss abuts against the surface of the return spring bracket.
6. The engine braking device with return and limit functions according to claim 1, characterized in that, The first connecting part includes a connecting post, and a connecting hole is provided in the connecting post, wherein the first mounting hole on the return spring bracket and the connecting hole are connected by fasteners.
7. The engine braking device with return and limit functions according to claim 1, characterized in that, The second connecting part includes a first mounting plane formed by a downward recess on the rocker arm shaft facing the return spring bracket, and the horizontal height of the first mounting plane is higher than the horizontal height of the abutment platform. A second mounting hole connected to the return spring bracket is provided on the first mounting plane.
8. The engine braking device with return and limit functions according to claim 7, characterized in that, Both ends of the rocker arm shaft along its axial direction are provided with a first mounting plane, and the first mounting planes at both ends of the rocker arm shaft are on the same horizontal plane.
9. The engine braking device with return and limit functions according to claim 1, characterized in that, A positioning part is provided on the abutment platform. The positioning part is nested and cooperates with the first elastic member. The radial degree of freedom of the first elastic member is limited by the positioning part. The positioning part is either a cavity or a positioning protrusion. When the positioning part is a cavity, one end of the first elastic member is embedded in the cavity and abuts against the bottom of the cavity. When the positioning part is a positioning protrusion, one end of the first elastic member is nested with the positioning protrusion and abuts against the surface of the abutment platform.
10. An engine braking device with return and limit functions, characterized in that, include: A camshaft, including an auxiliary cam, and having a non-working surface and a working surface on the outer contour of the auxiliary cam, wherein the distance between the working surface and the center of the base circle of the auxiliary cam is greater than the distance between the non-working surface and the center of the base circle of the auxiliary cam; A braking rocker arm and a rocker arm shaft are fitted through a shaft hole, and the braking rocker arm can reciprocate around the rocker arm shaft. The axial direction of the rocker arm shaft is parallel to the axial direction of the cam shaft. The side of the braking rocker arm extends horizontally to form an abutment platform. A limiting recess is provided on the outer surface of the rocker arm shaft, and the two sides of the limiting recess are a first abutment A surface and a first abutment B surface, respectively. The braking rocker arm is provided with a limiting protrusion that fits into the limiting recess. The two sides of the limiting protrusion are a second abutment A surface and a second abutment B surface, respectively. The relative distance between the second abutment A surface and the second abutment B surface is less than the relative distance between the first abutment A surface and the first abutment B surface. The rocker arm support has two ends that mate with the camshaft and the rocker arm shaft respectively, and the end of the rocker arm support that mates with the camshaft shaft is provided with a first connecting part; The second elastic element has one end connected to the first connecting part by a fastener, or connected to the second connecting part on the rocker arm shaft. The horizontal height of the first connecting part and the horizontal height of the second connecting part are both lower than the horizontal height of the abutting platform, and the horizontal height of the end of the second elastic element that abuts the abutting platform is lower than the horizontal height of the upper surface of the braking rocker arm. A sliding unit is slidably connected to one end of the brake rocker arm corresponding to the auxiliary cam, and the sliding unit is provided with a roller, wherein the axis of the roller is parallel to the axis of the camshaft. When the engine is working normally, there is a gap between the roller and the working surface of the auxiliary cam, and the first abutting surface A and the second abutting surface A abut against each other, and the second elastic element is in a deformed state. When the engine brake is engaged, the roller contacts the outer contour of the auxiliary cam. As the working surface and non-working surface on the auxiliary cam alternately contact the roller, the brake rocker arm swings back and forth around the rocker arm axis, and the limiting protrusion swings back and forth within the limiting recess.
11. The engine braking device with return and limit functions according to claim 10, characterized in that, The second elastic element is arranged in a Z-shaped plate shape, and the two ends of the second elastic element are the first connecting end and the second connecting end, respectively. The first connecting end forms a surface-to-surface contact with the rocker arm shaft and is connected and fixed by fasteners, while the second connecting end is in surface-to-surface contact with the abutment platform.
12. The engine braking device with return and limit functions according to claim 11, characterized in that, The abutting platform is provided with a positioning protrusion or a positioning recess, and the second connecting end of the second elastic member is provided with a corresponding positioning recess or a positioning protrusion. The relative sliding between the abutting platform and the second connecting end of the second elastic member is limited by the convex-concave fit between the positioning protrusion and the positioning recess.
13. The engine braking device with return and limit functions according to claim 10, characterized in that, The first connecting part includes a connecting post, and a connecting hole is provided in the connecting post, wherein the third mounting hole on the second elastic member is connected to the connecting hole by a fastener.
14. The engine braking device with return and limit functions according to claim 10, characterized in that, The second connecting part includes a second mounting plane formed by a downward recess on the side of the rocker arm shaft facing the second elastic member, and the horizontal height of the second mounting plane is lower than the horizontal height of the abutment platform. A fourth mounting hole connected to the second elastic member is provided on the second mounting plane.
15. The engine braking device with return and limit functions according to claim 14, characterized in that, The rocker arm shaft has a second mounting surface at both ends along its axial direction, and the second mounting surfaces at both ends of the rocker arm shaft are on the same horizontal plane.
16. An engine, characterized in that, The engine braking device with return and limit functions as described in claim 1 or 10.