An engine braking device and an engine with a return and limit function

Abstract

The present invention provides an engine braking device and an engine with a function of returning to position and limiting position, belonging to the technical field of automotive parts, including: a camshaft, which includes an auxiliary cam; a braking rocker arm and a rocker arm shaft that are in shaft-hole fit, wherein a contact platform extends horizontally along the side of the braking rocker arm, a limiting recess is provided on the outer surface of the rocker arm shaft, and a limiting protrusion is provided on the braking rocker arm; a rocker arm support provided with a first connecting portion; a return spring support, one end of which is connected to the first connecting portion, wherein the horizontal height of the first connecting portion and the horizontal height of the second connecting portion are both higher than the horizontal height of the contact platform, and the horizontal height of the return spring support is lower than the horizontal height of the upper surface of the braking rocker arm; a first elastic member, the two ends of which are clamped between the other end of the return spring support and the contact platform. The present invention reduces the size of the entire engine braking device in the vertical direction, making the structure more compact.

Description

Technical Field

[0001] The present invention belongs to the technical field of automotive parts, and relates to an engine braking device, in particular to an engine braking device and an engine with a return and limit function. Background Art

[0002] Engine braking technology refers to that during the driving process of an automobile, the driver lifts the accelerator pedal and releases the clutch, and uses the compression resistance generated during the compression stroke of the engine, as well as the intake and exhaust resistance and friction to form a braking force on the driving wheels, so as to brake the automobile. The application of engine braking technology effectively reduces the use frequency of the service brake. When the whole vehicle is on steep roads such as long downhill slopes and rough mountain roads, using engine braking can avoid the temperature rise of the brake friction pads caused by long-term use of the brake, resulting in a decrease in braking force or even loss of function.

[0003] Patent application (CN202110941484.X) discloses an energy-saving and consumption-reducing engine braking device, which includes a movable unit and a control mechanism. The movable unit is movably arranged at the rear end of the auxiliary rocker arm and corresponds to the auxiliary cam; the control mechanism can drive the movable unit to act, so that the movable unit has a first position in contact with the auxiliary cam and a second position separated from the auxiliary cam.

[0004] For the above-mentioned engine braking device, although the effect of energy saving and consumption reduction is achieved, the overall size of the engine braking device in the vertical direction is relatively large. After installation, there may be a situation of collision with the engine hood, which affects the engine braking effect. Summary of the Invention

[0005] The purpose of the present invention is to address the above problems existing in the prior art, and propose an engine braking device that can effectively reduce the size in the vertical direction and ensure the braking effect.

[0006] The purpose of the present invention can be achieved by the following technical solutions: An engine braking device with a return and limit function, comprising:

[0007] A camshaft, the camshaft includes an auxiliary cam, and a non-working surface and a working surface are provided on the outer contour of the auxiliary cam. Among them, the distance between the working surface and the center of the base circle on the auxiliary cam is greater than the distance between the non-working surface and the center of the base circle on the auxiliary cam;

[0008] A brake rocker arm and a rocker arm shaft are in shaft - hole fit, and the brake rocker arm can swing reciprocally around the rocker arm shaft. The axis direction of the rocker arm shaft is parallel to the axis direction of the camshaft. Among them, a contact platform is formed by the side part of the brake rocker arm extending horizontally. A limiting recess is arranged on the outer surface of the rocker arm shaft, and the two sides of the limiting recess are respectively a first contact A - surface and a first contact B - surface; a limiting protrusion which is in concave - convex fit with the limiting recess is arranged on the brake rocker arm. The two sides of the limiting protrusion are respectively a second contact A - surface and a second contact B - surface, and the relative distance between the second contact A - surface and the second contact B - surface is less than the relative distance between the first contact A - surface and the first contact B - surface;

[0009] A rocker arm support, the two ends of which are in shaft - hole fit with the camshaft and the rocker arm shaft respectively, and a first connecting part is arranged at one end of the rocker arm support which is in fit with the camshaft hole;

[0010] A return spring support, one end of which is connected to the first connecting part through a fastener or connected to a second connecting part on the rocker arm shaft. Among them, the horizontal height where the first connecting part is located and the horizontal height where the second connecting part is located are both higher than the horizontal height where the contact platform is located, and the horizontal height where the return spring support is located 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 a roller is arranged on the sliding unit. Among them, the axis direction of the roller is parallel to the axis direction of the camshaft;

[0012] A first elastic member is clamped between the other end of the return spring support and the contact platform at both ends. Among them, the axis of the first elastic member is offset to one side of the center - line connecting the centers of the auxiliary cam and the roller, and the first elastic member is located between the roller and the rocker arm shaft;

[0013] Among them, when the engine is working normally, there is a gap between the roller and the working surface of the auxiliary cam, and the first contact A - surface and the second contact A - surface are in contact with each other, and the first elastic member is in an energy - storage state;

[0014] When the engine brake is working, the roller is in contact with the outer contour of the auxiliary cam. As the working surface and the non - working surface on the auxiliary cam alternately contact the roller, the brake rocker arm swings reciprocally around the rocker arm shaft, and the limiting protrusion swings reciprocally in the limiting recess.

[0015] In the above - mentioned engine brake device with return and limiting functions, the position of the concave - convex fit between the limiting recess and the limiting protrusion is located on the right - hand side of the rocker arm shaft. Among them, 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.

[0016] In the above-described engine braking device with a return and a limit function, the limiting recess is a limiting hole, the limiting protrusion is a limiting pin screwed onto the braking rocker arm, and one end of the limiting pin passes through the limiting hole and extends into the rocker arm shaft. Among them, the diameter of the limiting hole is larger than the diameter of the end of the limiting pin that is inserted and mated with the limiting hole, and the first abutting surface A, the first abutting surface B, the second abutting surface A, and the second abutting surface B are arranged in an arc shape.

[0017] In the above-described engine braking device with a return and a limit function, the return spring bracket is arranged in a plate shape, and at one end of the return spring bracket, there is a first mounting hole that is inserted and mated with a fastener and mounts the return spring bracket on the rocker arm support. At the other end of the return spring bracket, there is a boss. Among them, an interference nested fit is formed between the boss and the first elastic member, and the end of the first elastic member that is mated with the boss abuts against the surface of the return spring bracket.

[0018] In the above-described engine braking device with a return and a limit function, the return spring bracket is arranged in a plate shape, and at one end of the return spring bracket, there is a first mounting hole that is inserted and mated with a fastener and mounts the return spring bracket on the rocker arm shaft. At the other end of the return spring bracket, there is a boss. Among them, an interference nested fit is formed between the boss and the first elastic member, and the end of the first elastic member that is mated with the boss abuts against the surface of the return spring bracket.

[0019] In the above-described engine braking device with a return and a limit function, the first connecting portion includes a connecting column, and a connecting hole is provided in the connecting column. Among them, the first mounting hole on the return spring bracket and the connecting hole are connected by a fastener.

[0020] In the above-described engine braking device with a return and a limit function, the second connecting portion includes a first mounting plane formed by a downward depression on one side of 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 abutting platform. Among them, a second mounting hole connected to the return spring bracket is provided on the first mounting plane.

[0021] In the above-described engine braking device with a return and a limit function, first mounting planes are 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 above-described engine braking device with a return and limit function, a positioning portion is provided on the abutting platform. The positioning portion is nested and cooperated with the first elastic member, and the radial freedom degree of the first elastic member is limited by the positioning portion. Wherein, the positioning portion is a concave cavity or a positioning protrusion. When the positioning portion is a concave cavity, one end of the first elastic member is embedded in the concave cavity and abuts against the bottom of the concave cavity; when the positioning portion is a positioning protrusion, one end of the first elastic member is nested with the positioning protrusion and abuts against the surface of the abutting platform.

[0023] The present invention also provides an engine braking device with a return and limit function, including:

[0024] A camshaft, the camshaft includes an auxiliary cam, and a non-working surface and a working surface are provided on the outer contour of the auxiliary cam. Wherein, the distance between the working surface and the center of the base circle on the auxiliary cam is greater than the distance between the non-working surface and the center of the base circle on the auxiliary cam;

[0025] A brake rocker arm and a rocker arm shaft that are in shaft hole fit, and the brake rocker arm can swing reciprocally around the rocker arm shaft. The axis direction of the rocker arm shaft is parallel to the axis direction of the camshaft. Wherein, a side portion of the brake rocker arm extends horizontally to form an abutting platform, a limiting concave portion is provided on the outer surface of the rocker arm shaft, and both sides of the limiting concave portion are a first abutting surface A and a first abutting surface B respectively; a limiting convex portion that is in concave-convex fit with the limiting concave portion is provided on the brake rocker arm. Both sides of the limiting convex portion are a second abutting surface A and a second abutting surface B respectively, and the relative distance between the second abutting surface A and the second abutting surface B is less than the relative distance between the first abutting surface A and the first abutting surface B;

[0026] A rocker arm support, the two ends are respectively in shaft hole fit with the camshaft and the rocker arm shaft, and a first connecting portion is provided at one end of the rocker arm support that is in shaft hole fit with the camshaft;

[0027] A second elastic member, one end is connected to the first connecting portion through a fastener, or connected to a second connecting portion on the rocker arm shaft. Wherein, the horizontal height where the first connecting portion is located and the horizontal height where the second connecting portion is located are both lower than the horizontal height where the abutting platform is located, and the horizontal height where the end of the second elastic member that abuts against the abutting platform is located is lower than the horizontal height of the upper surface of the brake rocker arm;

[0028] A sliding unit, slidably connected to one end of the brake rocker arm corresponding to the auxiliary cam, and a roller is provided on the sliding unit. Wherein, the axis direction of the roller is parallel to the axis direction of the camshaft;

[0029] Wherein, 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 member is in a deformed state;

[0030] When the engine brake is working, the roller contacts the outer contour of the auxiliary cam. As the working surface and the non-working surface on the auxiliary cam alternately contact the roller, the brake rocker arm swings reciprocally around the rocker arm shaft, and the limiting convex portion swings reciprocally within the limiting concave portion.

[0031] In the above engine brake device with a return and limiting function, the second elastic member is arranged in a Z-shaped plate form, and the two ends of the second elastic member are respectively a first connection end and a second connection end. Among them, the first connection end forms a surface-to-surface contact with the rocker arm shaft and is fixedly connected through a fastener, and the second connection end forms a surface-to-surface contact with the abutting platform.

[0032] In the above engine brake device with a return and limiting function, a positioning convex portion or a positioning concave portion is provided on the abutting platform, and a corresponding positioning concave portion or positioning convex portion is provided on the second connection end of the second elastic member. Among them, the relative sliding between the abutting platform and the second connection end of the second elastic member is limited by the concave-convex fit between the positioning convex portion and the positioning concave portion.

[0033] In the above engine brake device with a return and limiting function, the first connection portion includes a connecting column, and a connection hole is provided in the connecting column. Among them, the third mounting hole on the second elastic member is connected to the connection hole through a fastener.

[0034] In the above engine brake device with a return and limiting function, the second connection portion includes a second mounting plane formed by a depression on one 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 abutting platform. Among them, a fourth mounting hole connected to the second elastic member is provided on the second mounting plane.

[0035] In the above engine brake device with a return and limiting function, second mounting planes are 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 above engine brake device with a return and limiting function.

[0037] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0038] (1). The engine brake device with a return and limiting function provided by the present invention reduces the size of the entire engine brake device in the vertical direction, making the structure more compact. In addition, through the concave-convex fit between the limiting convex portion and the limiting concave portion, on the one hand, it ensures that the roller and the auxiliary cam do not contact during the normal operation of the engine, reduces the friction work, and reduces the fuel consumption of the engine. On the other hand, it can control the amplitude of the reciprocating swing of the brake rocker arm during the braking stage of the engine, improving the braking effect.

[0039] (2) A positioning portion is provided on the abutting platform to ensure that the elastic member always moves along the axial direction of the elastic member during the process of stretching or compressing, without torsion or deviation.

[0040] (3) The elastic member is configured as a plate-like structure, so that the elastic member not only contacts the abutting platform surface-to-surface, but also contacts the second installation plane surface-to-surface, and the connection firmness and reliability in use of the elastic member are improved by increasing the contact area. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 It is a schematic structural diagram of an engine braking device with a return and limit function according to the present invention.

[0042] Figure 2 It is a schematic structural diagram of an engine braking device with a return and limit function according to the present invention when the engine is operating normally.

[0043] Figure 3 It is a schematic structural diagram of an engine braking device with a return and limit function according to the present invention when the engine is in the engine braking state.

[0044] Figure 4 It is Figure 2 An enlarged view of part A in

[0045] Figure 5 It is Figure 3 An enlarged view of part B in

[0046] Figure 6 It is a schematic structural diagram of a braking rocker arm in a preferred embodiment of the present invention.

[0047] Figure 7 It is a schematic structural diagram of a rocker arm shaft in a preferred embodiment of the present invention.

[0048] Figure 8 It is a schematic structural diagram of a return spring bracket in a preferred embodiment of the present invention.

[0049] Figure 9 It is a cross-sectional view of the cooperation between a return spring bracket and a first elastic member in a preferred embodiment of the present invention.

[0050] Figure 10 It is a schematic structural diagram of another embodiment of an engine braking device with a return and limit function according to the present invention.

[0051] Figure 11 It is Figure 10 A schematic structural diagram of the rocker arm shaft shown in

[0052] Figure 12 It is Figure 10Schematic structural diagram of the second elastic member shown in the figure.

[0053] In the figure,

[0054] 10. Camshaft; 11. Auxiliary cam; 111. Non-working surface; 112. Working surface;

[0055] 20. Brake rocker arm; 21. Contact platform; 211. Positioning part; 22. Limit convex part; 221. Second contact A surface; 222. Second contact B surface;

[0056] 30. Rocker shaft; 31. Limit recess; 311. First contact A surface; 312. First contact B surface; 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 support; 51. First mounting hole; 52. Boss;

[0059] 60. Sliding unit; 61. Roller;

[0060] 70. First elastic member;

[0061] 80. Second elastic member; 81. First connecting end; 82. Second connecting end; 83. Third mounting hole. Specific embodiments

[0062] The following are specific embodiments of the present invention and in conjunction with the accompanying drawings, the technical solutions of the present invention will be further described, but 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...) in the embodiments of the present invention are only used to explain the relative positional relationship and movement conditions between components in a specific posture (as shown in the drawings). If the specific posture changes, the directional indications will also change accordingly.

[0064] Embodiment 1

[0065] As Figures 1 to 9 shown, an engine braking device with a return and limit function provided by the present invention includes:

[0066] A camshaft 10, 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. Among them, the distance between the working surface 112 and the base circle center of the auxiliary cam 11 is greater than the distance between the non-working surface 111 and the base circle center of the auxiliary cam 11;

[0067] A brake rocker arm 20 and a rocker arm shaft 30 are in shaft - hole fit, and the brake rocker arm 20 can swing reciprocally around the rocker arm shaft 30. The axial direction of the rocker arm shaft 30 is parallel to the axial direction of the camshaft 10. Among them, a contact platform 21 is formed by the side part of the brake rocker arm 20 extending horizontally. A limiting recess 31 is arranged on the outer surface of the rocker arm shaft 30, and the two sides of the limiting recess 31 are respectively a first contact A - surface 311 and a first contact B - surface 312; A limiting convex part 22 which is in concave - convex fit with the limiting recess 31 is arranged on the brake rocker arm 20. The two sides of the limiting convex part 22 are respectively a second contact A - surface 221 and a second contact B - surface 222, and the relative distance between the second contact A - surface 221 and the second contact B - surface 222 is less than the relative distance between the first contact A - surface 311 and the first contact B - surface 312;

[0068] A rocker arm support 40 is in shaft - hole fit with the camshaft 10 and the rocker arm shaft 30 at both ends respectively, and a first connecting part 41 is arranged at one end of the rocker arm support 40 which is in shaft - hole fit with the camshaft 10;

[0069] A return spring support 50 is connected to the first connecting part 41 through a fastener at one end, or is connected to a second connecting part 32 on the rocker arm shaft 30. Among them, the horizontal height where the first connecting part 41 is located and the horizontal height where the second connecting part 32 is located are both higher than the horizontal height where the contact platform 21 is located, and the horizontal height where the return spring support 50 is located is lower than the horizontal height of the upper surface of the brake rocker arm 20;

[0070] A sliding unit 60 is slidably connected to one end of the brake rocker arm 20 corresponding to the auxiliary cam 11, and a roller 61 is arranged on the sliding unit 60. Among them, the axial direction of the roller 61 is parallel to the axial direction of the camshaft 10;

[0071] A first elastic member 70 is clamped between the other end of the return spring support 50 and the contact platform 21 at both ends, and the telescopic direction of the first elastic member 70 is parallel to the center - line connection of the auxiliary cam 11 and the roller 61. Among them, the axis of the first elastic member 70 is offset to one side of the center - line connection of the auxiliary cam 11 and the roller 61, and the first elastic member 70 is located between the roller 61 and the rocker arm shaft 30;

[0072] Among them, 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 contact A - surface 311 and the second contact A - surface 221 are in contact with each other, and the first elastic member 70 is in an energy - storage state;

[0073] When the engine braking works, 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 braking rocker arm 20 swings reciprocally around the rocker arm shaft 30, and the limiting convex portion 22 swings reciprocally within the limiting concave portion 31.

[0074] An engine braking device with a return and limiting function provided by the present invention reduces the size of the entire engine braking device in the vertical direction, making the structure more compact. In addition, through the concave-convex cooperation between the limiting convex portion 22 and the limiting concave portion 31, on the one hand, it ensures that the roller 61 does not contact the auxiliary cam 11 during the normal operation of the engine, reducing the friction work and the fuel consumption of the engine. On the other hand, it can control the amplitude of the reciprocal swing of the braking rocker arm 20 during the braking stage of the engine, improving the braking effect.

[0075] It is further pointed out that the position of the concave-convex cooperation between the limiting concave portion 31 and the limiting convex portion 22 is located on the right half side of the rocker arm shaft 30. Among them, the extension line of the axis of the limiting convex portion 22 passes through the center of the cross-section of the rocker arm shaft 30 where the limiting convex portion 22 is located.

[0076] Preferably, the limiting concave portion 31 is a limiting hole, the limiting convex portion 22 is a limiting pin screwed on the braking rocker arm 20, and one end of the limiting pin passes through the limiting hole and extends into the rocker arm shaft 30. Among them, the diameter of the limiting hole is larger than the diameter of the end of the limiting pin that is inserted and matched with the limiting hole, and the first abutting A surface 311, the first abutting B surface 312, the second abutting A surface 221, and the second abutting B surface 222 are arranged in an arc shape.

[0077] It is worth mentioning that when the engine is working normally, the first abutting A surface 311 and the second abutting A surface 221 abut against each other. At this time, the first elastic member 70 is in an energy storage state, and the roller 61 does not contact the working surface 112 of the auxiliary cam 11 under the action of the sliding unit 60. When the engine is in the braking state, the roller 61 extends out and contacts the outer contour of the auxiliary cam 11 under the action of the sliding unit 60, and the abutment between the first abutting A surface 311 and the second abutting A surface 221 is released. As the roller 61 alternately passes through the working surface 112 and the non-working surface 111 of the auxiliary cam 11, the limiting convex portion 22 swings reciprocally within the limiting concave portion 31. And during the reciprocal swing of the limiting convex portion 22, the first abutting A surface 311 and the second abutting A surface 221 do not contact, and the first abutting B surface 312 and the second abutting B surface 222 do not contact. When the engine braking is completed and it turns back to the normal working state, 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 A surface 311 and the second abutting A surface 221 abut against each other again.

[0078] Preferably, the return spring bracket 50 is arranged in a plate shape, and a first mounting hole 51 for inserting and cooperating with a fastener and mounting the return spring bracket 50 on the rocker arm support 40 is provided at one end of the return spring bracket 50. A boss 52 is provided at the other end of the return spring bracket 50. Among them, an interference nested fit is formed between the boss 52 and the first elastic member 70, and one end of the first elastic member 70 that cooperates with the boss 52 abuts against the surface of the return spring bracket 50.

[0079] In this embodiment, the boss 52 on the return spring bracket 50 is generally formed by riveting. The formed boss 52 has elasticity, can form tension on 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, improving the reliability of the connection between the two.

[0080] It is worth mentioning that one end where the first mounting hole 51 on the return spring bracket 50 is provided 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.

[0081] Preferably, the first connecting portion 41 includes a connecting column 411, and a connecting hole 412 is provided in the connecting column 411. Among them, the first mounting hole 51 on the return spring bracket 50 is connected to the connecting hole 412 through a fastener.

[0082] Preferably, the second connecting portion 32 includes a first mounting plane 321 formed by a downward depression on one side of 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. Among them, a second mounting hole 322 connected to the return spring bracket 50 is provided on the first mounting plane 321.

[0083] It is worth mentioning that when one end of the return spring bracket 50 is connected to the rocker arm shaft 30, the reason for providing the first mounting plane 321 for connecting the return spring bracket 50 on the rocker arm shaft 30, and the first mounting plane 321 is formed by a downward depression from the arc surface of the rocker arm shaft 30, is that this can control and position the position of the return spring bracket 50 on the first mounting plane 321, avoid relative slippage between the two when they are connected, and thus improve the reliability of the connection between the two.

[0084] Furthermore, first mounting planes 321 are provided at both ends of the rocker arm shaft 30 along its axial direction, and the first mounting planes 321 at both ends of the rocker arm shaft 30 are on the same horizontal plane.

[0085] In this embodiment, a first mounting plane 321 is provided at each end of the rocker shaft 30 to achieve anti-fool installation of the rocker shaft 30. It is worth mentioning that a limiting recess 31 is also provided at each end of the rocker shaft 30, so that a true "symmetrical arrangement" of the rocker shaft 30 is achieved, ensuring the assembly efficiency of the engine braking device.

[0086] Preferably, a positioning portion 211 is provided on the abutting platform 21. The positioning portion 211 is nested and matched with the first elastic member 70 to limit the radial degree of freedom of the first elastic member 70 through the positioning portion 211. Among them, the positioning portion 211 is a concave cavity or a positioning protrusion. When the positioning portion 211 is a concave cavity, one end of the first elastic member 70 is embedded in the concave cavity and abuts against the bottom of the concave cavity; when the positioning portion 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 abutting platform 21.

[0087] It is worth mentioning that the positioning portion 211 is provided on the abutting platform 21 to ensure that the first elastic member 70 always moves along the axis direction of the first elastic member 70 during the process of stretching or compressing, without torsion or deviation.

[0088] In addition, in order to reduce the number of assembled parts and improve the assembly efficiency, it is best to directly integrate the positioning portion 211 on the abutting platform 21. Therefore, the positioning portion 211 can be selected as a concave cavity or a positioning protrusion. Among them, the concave cavity refers to a cavity whose cavity opening is flush with the upper surface of the abutting platform 21 and whose cavity bottom is lower than the upper surface of the abutting platform 21. The positioning protrusion refers to a step whose bottom is flush with the upper surface of the abutting platform 21 and whose top is higher than the upper surface of the abutting platform 21. When the positioning portion 211 is a concave cavity, the first elastic member 70 is inserted into the positioning portion 211; when the positioning portion 211 is a positioning protrusion, the positioning portion 211 is inserted into the first elastic member 70.

[0089] Therefore, in order to increase the contact area between the positioning portion 211 and the first elastic member 70, the positioning portion 211 is generally set to be circular, and the first elastic member 70 here is a cylindrical spring, which is generally also circularly arranged.

[0090] It is further pointed out that the positioning portion 211 is not limited to being integrally formed on the abutting platform 21, and can also be installed on the abutting platform 21 through a certain structure to achieve the effect of positioning the first elastic member 70.

[0091] Embodiment 2

[0092] Such as Figures 1 to 12As shown, compared with the first embodiment, the difference in this embodiment is that the first elastic member 70 in the first embodiment is a cylindrical elastic member, while the second elastic member 80 in this embodiment is a plate-shaped elastic member. Therefore, for the installation of the cylindrical elastic member in the first embodiment, it is clearly pointed out that a return spring bracket 50 is added, and one end of the return spring bracket 50 is connected to the first connecting portion 41 through a fastener, or connected to the second connecting portion 32 on the rocker shaft 30. Among them, the horizontal height of the first connecting portion 41 and the horizontal height of the second connecting portion 32 are both higher than the horizontal height of the abutting 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 20.

[0093] In this embodiment, the return spring bracket 50 is not provided. Therefore, for the installation of the plate-shaped elastic member, it is clearly pointed out that one end of the second elastic member 80 is connected to the first connecting portion 41 through a fastener, or connected to the second connecting portion 32 on the rocker shaft 30. Among them, the horizontal height of the first connecting portion 41 and the horizontal height of the second connecting portion 32 are both lower than the horizontal height of the abutting platform 21, and the horizontal height of the end of the second elastic member 80 that abuts against the abutting platform 21 is lower than the horizontal height of the upper surface of the brake rocker 20.

[0094] It is worth mentioning that when the first elastic member 70 is a cylindrical second elastic member, the horizontal heights of the first connecting portion 41 and the second connecting portion 32 are both higher than the horizontal height of the abutting platform 21; when the second elastic member 80 is a plate-shaped elastic member, the horizontal heights of the first connecting portion 41 and the second connecting portion 32 are both lower than the horizontal height of the abutting platform 21.

[0095] Whether it is the engine braking device in the first embodiment or the engine braking device in the second embodiment, both can reduce the overall vertical dimension of the engine braking device, making the structure more compact.

[0096] Furthermore, it is pointed out that the second elastic member 80 is arranged in a Z-shaped plate, and the two ends of the second elastic member 80 are respectively a first connection end 81 and a second connection end 82. Among them, the first connection end 81 forms a surface-to-surface contact with the second installation plane on the rocker shaft 30 and is fixedly connected through a fastener, and the second connection end 82 forms a surface-to-surface contact with the abutting platform 21. Among them, a fourth installation hole is provided on the second installation plane.

[0097] In this embodiment, the second elastic member 80 is arranged in a plate-shaped structure, so as to realize that the second elastic member 80 not only forms a surface-to-surface contact with the abutting platform 21, but also forms a surface-to-surface contact with the second installation plane, and improves the firmness of the connection and the reliability of use of the second elastic member 80 by increasing the contact area.

[0098] It is further pointed out that the structure of the second mounting plane and the fourth mounting hole provided on the second mounting plane is the same as that of the first mounting plane 321 and the second mounting hole 322 provided on the first mounting plane 321. Among them, a third mounting hole 83 connected to the fourth mounting hole is provided on the second elastic member 80.

[0099] It is further pointed out that in addition to directly adopting surface-to-surface contact between the abutting platform 21 and the second connecting end 82 of the second elastic member 80, a positioning convex portion or a positioning concave portion may be provided on the abutting platform 21, and a corresponding positioning concave portion or positioning convex portion is provided on the second connecting end 82 of the second elastic member 80. Among them, the relative sliding between the abutting platform 21 and the second connecting end 82 of the second elastic member 80 is limited by the concave-convex fit between the positioning convex portion and the positioning concave portion.

[0100] It is worth mentioning that the function of providing the positioning convex portion and the positioning concave portion on the abutting platform 21 and the second elastic member 80 is the same as that of providing the positioning portion 211 in the first embodiment. Therefore, it will not be elaborated here.

[0101] It should be noted that in the present invention, descriptions such as "first", "second", and "one" are only for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include at least one such feature. In the description of the present invention, the meaning of "a plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined. Terms such as "connection" and "fixation" should be understood in a broad sense. For example, "fixation" may be a fixed connection, a detachable connection, or integrated; it may be a mechanical connection or an electrical connection; it may be directly connected or indirectly connected through an intermediate medium, and may be the internal communication of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0102] In addition, the technical solutions between the various embodiments of the present invention can be combined with each other, but it must be based on the fact that those of ordinary skill in the art can implement them. When the combination of technical solutions results in contradictions or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the protection scope required by the present invention.

[0103] The specific embodiments described herein are only illustrative of the spirit of the present invention. Those skilled in the art of the present invention can make various modifications or supplements to the described specific embodiments or use similar methods to replace them, but will not deviate from the spirit of the present invention or exceed the scope defined by the appended claims.

Claims

1. An engine braking device with return and limit functions, characterized in that: include: A camshaft, the camshaft comprising an auxiliary cam, wherein a non-working surface and a working surface are provided on the outer contour of the auxiliary cam, wherein a distance between the working surface and a center point of a base circle on the auxiliary cam is greater than a distance between the non-working surface and a center point of a base circle on the auxiliary cam; A brake rocker arm and a rocker arm shaft matched through an axial hole, and the brake rocker arm can swing back and forth around the rocker arm shaft, and the axial direction of the rocker arm shaft is parallel to the axial direction of the camshaft, wherein the side portion of the brake rocker arm extends in a horizontal direction 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 respectively a first abutment A surface and a first abutment B surface; a limiting convex portion is provided on the brake rocker arm that is concave-convexly matched with the limiting recess, and the two sides of the limiting convex portion are respectively a second abutment A surface and a second abutment B surface, and the relative distance between the second abutment A surface and the second abutment B surface is smaller than the relative distance between the first abutment A surface and the first abutment B surface; A rocker arm support, both ends of which are respectively matched with the camshaft and the rocker arm shaft hole, and a first connecting portion is provided on one end of the rocker arm support that is matched with the camshaft shaft hole; a return spring bracket, one end of which is connected to the first connection portion, or to the second connection portion on the rocker arm shaft, through a fastener, wherein the level of the first connection portion and the level of the second connection portion are both higher than the level of the abutment platform, and the level of the return spring bracket is lower than the level of the upper surface of the brake rocker arm; a sliding unit, slidably connected to an end of the brake rocker arm corresponding to the auxiliary cam, and provided with a roller, wherein the axis direction of the roller is parallel to the axis direction of the camshaft; A first elastic member, both ends of which are clamped between the other end of the return spring bracket and the abutment platform, wherein the axis of the first elastic member is offset to one side of a line connecting the centers of the auxiliary cam and the roller, and the first elastic member is located between the roller and the rocker arm shaft; Wherein, when the engine works 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 each other, and the first elastic member is in an energy storage state; When the engine brake is working, the roller contacts the outer contour of the auxiliary cam, and as the working surface and the non-working surface on the auxiliary cam contact the roller alternately, the braking rocker arm swings back and forth around the rocker arm shaft, and the limiting protrusion swings back and forth in 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 matching between the limiting concave portion and the limiting convex portion is located on the right half of the rocker arm shaft, wherein the extension line of the axis of the limiting convex portion passes through the center of the cross section of the rocker arm shaft where the limiting convex portion 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, the limiting protrusion is a limiting pin screwed on the brake rocker arm, and one end of the limiting pin passes through the limiting hole and extends into the rocker arm shaft, wherein the aperture of the limiting hole is larger than the diameter of one end of the limiting pin that is plugged into the limiting hole, and the first abutment A surface, the first abutment B surface, the second abutment A surface and the second abutment B surface are arranged in arc surfaces.

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 arranged in a plate shape, and a first mounting hole is arranged at one end of the return spring bracket for plugging and cooperating with a fastener and mounting the return spring bracket on the rocker arm support, and a boss is arranged at the other end of the return spring bracket, wherein an interference fit is formed between the boss and the first elastic member, and the end of the first elastic member cooperating 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 to 3, characterized in that: The return spring bracket is arranged in a plate shape, and a first mounting hole is arranged at one end of the return spring bracket for plugging and cooperating with a fastener and mounting the return spring bracket on the rocker arm shaft, and a boss is arranged at the other end of the return spring bracket, wherein an interference fit is formed between the boss and the first elastic member, and the end of the first elastic member cooperating 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 portion includes a connecting column, and a connecting hole is arranged in the connecting column, wherein the first mounting hole on the return spring bracket is connected to the connecting hole via a fastener.

7. The engine braking device with return and limit functions according to claim 1, characterized in that: The second connecting portion includes a first mounting plane formed by a downward depression on one side of the rocker arm shaft toward the return spring bracket, and the horizontal height of the first mounting plane is higher than the horizontal height of the abutment platform, wherein 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: The first mounting planes are arranged at both ends of the rocker arm shaft along the axial direction thereof, 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 portion is provided on the abutment platform, and the positioning portion is nested with the first elastic member, and the radial freedom of the first elastic member is limited by the positioning portion, wherein the positioning portion is a concave cavity or a positioning protrusion, and when the positioning portion is a concave cavity, one end of the first elastic member is embedded in the concave cavity and abuts against the bottom of the cavity; when the positioning portion 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, the camshaft comprising an auxiliary cam, wherein a non-working surface and a working surface are provided on the outer contour of the auxiliary cam, wherein a distance between the working surface and a center point of a base circle on the auxiliary cam is greater than a distance between the non-working surface and a center point of a base circle on the auxiliary cam; A brake rocker arm and a rocker arm shaft matched through an axial hole, and the brake rocker arm can swing back and forth around the rocker arm shaft, and the axial direction of the rocker arm shaft is parallel to the axial direction of the camshaft, wherein the side portion of the brake rocker arm extends in a horizontal direction 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 respectively a first abutment A surface and a first abutment B surface; a limiting convex portion is provided on the brake rocker arm that is concave-convexly matched with the limiting recess, and the two sides of the limiting convex portion are respectively a second abutment A surface and a second abutment B surface, and the relative distance between the second abutment A surface and the second abutment B surface is smaller than the relative distance between the first abutment A surface and the first abutment B surface; A rocker arm support, both ends of which are respectively matched with the camshaft and the rocker arm shaft hole, and a first connecting portion is provided on one end of the rocker arm support that is matched with the camshaft shaft hole; A second elastic member, one end of which is connected to the first connection portion, or to the second connection portion on the rocker arm shaft, through a fastener, wherein the level of the first connection portion and the level of the second connection portion are both lower than the level of the abutment platform, and the level of the end of the second elastic member abutting against the abutment platform is lower than the level of the upper surface of the brake rocker arm; a sliding unit, slidably connected to an end of the brake rocker arm corresponding to the auxiliary cam, and provided with a roller, wherein the axis direction of the roller is parallel to the axis direction of the camshaft; Wherein, when the engine works 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 each other, and the second elastic member is in a deformed state; When the engine brake is working, the roller contacts the outer contour of the auxiliary cam, and as the working surface and the non-working surface on the auxiliary cam contact the roller alternately, the braking rocker arm swings back and forth around the rocker arm shaft, and the limiting protrusion swings back and forth in the limiting recess.

11. The engine braking device with return and limit functions according to claim 10, characterized in that: The second elastic member is arranged in a Z-shaped plate shape, and the two ends of the second elastic member are respectively a first connecting end and a second connecting end, wherein the first connecting end forms a surface-to-surface contact with the rocker arm shaft and is connected and fixed by a fastener, and the second connecting end forms a surface-to-surface contact with the abutting platform.

12. The engine braking device with return and limit functions according to claim 11, characterized in that: A positioning protrusion or a positioning recess is provided on the abutment platform, and a corresponding positioning recess or the positioning protrusion is provided on the second connecting end of the second elastic member, wherein the relative sliding between the abutment platform and the second connecting end of the second elastic member is limited by the concave-convex cooperation 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 portion includes a connecting column, and a connecting hole is arranged in the connecting column, wherein the third mounting hole on the second elastic member is connected to the connecting hole via a fastener.

14. The engine braking device with return and limit functions according to claim 10, characterized in that: The second connecting portion includes a second mounting plane formed by a downward depression on one side of the rocker arm shaft toward the second elastic member, and the horizontal height of the second mounting plane is lower than the horizontal height of the abutment platform, wherein 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 is provided with a second installation plane at both ends along the axial direction thereof, and the second installation planes at both ends of the rocker arm shaft are on the same horizontal plane.

16. An engine, characterized in that: The invention comprises the engine braking device with return and limit functions as described in claim 1 or 10.

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