Engine braking device with returning and limiting functions and engine

Abstract

The invention provides an engine braking device with returning and limiting functions and an engine, and belongs to the technical field of automobile parts. The brake rocker arm and the rocker arm shaft are matched through a shaft hole, the side portion of the brake rocker arm extends in the horizontal direction to form an abutting platform, a limiting concave part is arranged on the outer surface of the rocker arm shaft, and a limiting convex part is arranged on the brake rocker arm; the rocker arm support is provided with a first connecting part; one end of the return spring support is connected with the first connecting part, 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 abutting platform, and the horizontal height of the return spring support is lower than the horizontal height of the upper surface of the brake rocker arm; the two ends of the first elastic piece are clamped between the other end of the return spring support and the abutting platform. According to the engine braking device, the size of the whole engine braking device in the vertical direction is reduced, and the structure is more compact.

Description

Technical Field

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

[0002] Engine braking technology refers to the process of braking the car by lifting the accelerator pedal and releasing the clutch while the car is driving, using the compression resistance generated during the engine compression stroke, as well as the braking force formed by the intake and exhaust resistance and friction on the drive wheels. The application of engine braking technology effectively reduces the frequency of using the service brakes. When the vehicle is going down a long slope, rugged mountain roads and other steep roads, using engine braking can avoid the increase in the temperature of the brake friction plate due to long-term use of the brake, which causes the braking force to decrease or even lose its effect.

[0003] The 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 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 move so that the movable unit has a first position in which the movable unit maintains contact with the auxiliary cam, and a second position separated from the auxiliary cam.

[0004] Although the engine braking device described above achieves the effect of energy saving and consumption reduction, the entire engine braking device has a large size in the vertical direction. After installation, it may collide with the engine cover, affecting the engine braking effect. Summary of the invention

[0005] The purpose of the present invention is to address the above-mentioned problems in the prior art and to propose an engine braking device which can effectively reduce the vertical dimension and ensure the braking effect.

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

[0007] 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 of a base circle on the auxiliary cam is greater than a distance between the non-working surface and a center of a base circle on the auxiliary cam;

[0008] 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 cam shaft, wherein the side portion of the brake rocker arm extends in a horizontal direction to form an abutment platform, and 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 matched with the limiting recess is provided on the brake rocker arm, 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;

[0009] The rocker arm support has two ends 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 matched with the camshaft shaft hole;

[0010] 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;

[0011] A sliding unit is slidably connected to an 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 cam shaft;

[0012] 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;

[0013] 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;

[0014] 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 contact the roller alternately, the brake rocker arm swings back and forth around the rocker arm shaft, and the limiting protrusion swings back and forth in the limiting concave portion.

[0015] In the above-mentioned engine braking device with return and limit functions, the position of the concave-convex matching between the limiting concave part and the limiting convex part is located on the right half of the rocker shaft, wherein the extension line of the axis of the limiting convex part passes through the center of the cross section of the rocker shaft where the limiting convex part is located.

[0016] In the above-mentioned engine braking device with return and limit functions, the limiting recess is a limiting hole, the limiting protrusion is a limiting pin screwed on the braking 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.

[0017] In the above-mentioned engine braking device with return and limit functions, 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 the 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.

[0018] In the above-mentioned engine braking device with return and limit functions, 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, which is plug-matched with the fastener and mounts the return spring bracket on the rocker shaft. 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 that cooperates with the boss abuts against the surface of the return spring bracket.

[0019] In the above-mentioned engine braking device with return and limit functions, the first connecting part 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 by a fastener.

[0020] In the above-mentioned engine braking device with return and limit functions, the second connecting part 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 arranged on the first mounting plane.

[0021] In the above-mentioned engine brake device with return and limit functions, first mounting planes are arranged 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-mentioned engine braking device with return and limit functions, 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. 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.

[0023] The present invention also provides an engine braking device with return and limit functions, comprising:

[0024] 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 of a base circle on the auxiliary cam is greater than a distance between the non-working surface and a center of a base circle on the auxiliary cam;

[0025] 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 cam shaft, wherein the side portion of the brake rocker arm extends in a horizontal direction to form an abutment platform, and 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 matched with the limiting recess is provided on the brake rocker arm, 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;

[0026] The rocker arm support has two ends 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 matched with the camshaft shaft hole;

[0027] 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 the abutment platform is lower than the level of the upper surface of the brake rocker arm;

[0028] A sliding unit is slidably connected to an 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 cam shaft;

[0029] 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;

[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 contact the roller alternately, the brake rocker arm swings back and forth around the rocker arm shaft, and the limiting protrusion swings back and forth in the limiting concave portion.

[0031] In the above-mentioned engine braking device with return and limit functions, 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 abutment platform.

[0032] In the above-mentioned engine braking device with return and limit functions, a positioning convex portion or a positioning concave portion is arranged on the abutment platform, and a corresponding positioning concave portion or a positioning convex portion is arranged 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 convex portion and the positioning concave portion.

[0033] In the above-mentioned engine braking device with return and limit functions, the first connecting part 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 by a fastener.

[0034] In the above-mentioned engine braking device with return and limit functions, the second connecting part 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 arranged on the second mounting plane.

[0035] In the above-mentioned engine brake device with return and limit functions, second mounting planes are arranged 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, comprising the engine braking device with return and limit functions.

[0037] Compared with the prior art, the present invention has the following beneficial effects:

[0038] (1) The engine brake device with return and limit functions provided by the present invention reduces the vertical dimension of the entire engine brake device, making the structure more compact. In addition, through the concave-convex cooperation between the limit convex part and the limit concave part, on the one hand, it ensures that the roller and the auxiliary cam do not contact when the engine is working normally, thereby 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 portion is provided on the abutment platform to ensure that the elastic member always moves along the axial direction of the elastic member during the stretching or compression process without twisting or deflecting.

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

[0041] Figure 1 The invention discloses a structural schematic diagram of an engine braking device with return and limit functions.

[0042] Figure 2 The present invention is a schematic structural diagram of an engine braking device with return and limit functions when the engine is working normally.

[0043] Figure 3 The present invention is a structural schematic diagram of an engine braking device with return and limit functions in an engine braking state.

[0044] Figure 4 yes Figure 2 Enlarged view of part A.

[0045] Figure 5 yes Figure 3 Enlarged view of part B.

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

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

[0051] Fig.11 yes Fig.10 Schematic diagram of the structure of the rocker shaft shown in .

[0052] Fig.12 yes Fig.10Schematic diagram of the structure of the second elastic member shown in .

[0053] In the figure,

[0054] 10. camshaft; 11. auxiliary cam; 111. non-working surface; 112. working surface;

[0055] 20. Braking rocker arm; 21. Abutment platform; 211. Positioning portion; 22. Position limiting convex portion; 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 portion; 321, first mounting plane; 322, second mounting hole;

[0057] 40. rocker arm support; 41. first connecting portion; 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. a first elastic member;

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

[0062] The following are specific embodiments of the present invention and the accompanying drawings to further describe the technical solution of the present invention, but the present invention is not limited to these embodiments.

[0063] It should be noted that all directional indications in the embodiments of the present invention (such as up, down, left, right, front, back, etc.) are only used to explain the relative position relationship, movement status, etc. between the components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0064] Embodiment 1

[0065] like Figures 1 to 9 As shown, the present invention provides an engine braking device with return and limit functions, comprising:

[0066] A camshaft 10, comprising an auxiliary cam 11, wherein a non-working surface 111 and a working surface 112 are provided on the outer contour of the auxiliary cam 11, wherein a distance between the working surface 112 and the center of a base circle on the auxiliary cam 11 is greater than a distance between the non-working surface 111 and the center of a base circle on the auxiliary cam 11;

[0067] The brake rocker arm 20 and the rocker shaft 30 are matched through the shaft hole, and the brake rocker arm 20 can swing back and forth around the rocker shaft 30, and the axial direction of the rocker shaft 30 is parallel to the axial direction of the camshaft 10, wherein the side of the brake rocker arm 20 extends in the horizontal direction to form an abutment platform 21, and a limiting recess 31 is provided on the outer surface of the rocker shaft 30, and the two sides of the limiting recess 31 are respectively a first abutment A surface 311 and a first abutment B surface 312; the brake rocker arm 20 is provided with a limiting convex portion 22 that is matched with the limiting recess 31, and the two sides of the limiting convex portion 22 are respectively a second abutment A surface 221 and a second abutment B surface 222, and the relative distance between the second abutment A surface 221 and the second abutment B surface 222 is smaller than the relative distance between the first abutment A surface 311 and the first abutment B surface 312;

[0068] The rocker arm support 40 has two ends respectively matched with the shaft holes of the camshaft 10 and the rocker arm shaft 30, and the end of the rocker arm support 40 matched with the shaft hole of the camshaft 10 is provided with a first connecting portion 41;

[0069] A return spring bracket 50, one end of which is connected to the first connection portion 41 or the second connection portion 32 on the rocker arm shaft 30 through a fastener, wherein the level of the first connection portion 41 and the level of the second connection portion 32 are both higher than the level of the abutment platform 21, and the level of the return spring bracket 50 is lower than the level of the upper surface of the brake rocker arm 20;

[0070] A sliding unit 60 is slidably connected to an end of the brake rocker arm 20 corresponding to the auxiliary cam 11, and a roller 61 is provided on the sliding unit 60, wherein the axis direction of the roller 61 is parallel to the axis direction of the camshaft 10;

[0071] The first elastic member 70 has two ends clamped between the other end of the return spring bracket 50 and the abutment platform 21, and the extension direction of the first elastic member 70 is parallel to the line connecting the centers of the auxiliary cam 11 and the roller 61, wherein the axis of the first elastic member 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 member 70 is located between the roller 61 and the rocker arm shaft 30;

[0072] 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 A 311 and the second abutting surface A 221 abut against each other, and the first elastic member 70 is in an energy storage state;

[0073] When the engine brake is working, 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 contact the roller 61 alternately, the braking rocker arm 20 swings back and forth around the rocker arm shaft 30, and the limiting protrusion 22 swings back and forth in the limiting recess 31.

[0074] The engine braking device with return and limit functions provided by the present invention reduces the vertical size of the entire engine braking device, 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 and the auxiliary cam 11 do not contact each other when the engine is working normally, thereby reducing friction work and reducing engine fuel consumption. On the other hand, it can control the amplitude of the reciprocating swing of the braking rocker arm 20 when the engine is in the braking stage, thereby improving the braking effect.

[0075] It is further pointed out that the position of the concave-convex matching between the limiting concave portion 31 and the limiting convex portion 22 is located on the right half of the rocker arm shaft 30, wherein 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 recess 31 is a limiting hole, the limiting protrusion 22 is a limiting pin screwed on the brake rocker arm 20, and one end of the limiting pin passes through the limiting hole and extends into the rocker arm shaft 30, 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 311, the first abutment B surface 312, the second abutment A surface 221 and the second abutment B surface 222 are arranged in arc surfaces.

[0077] It is worth mentioning that when the engine is working normally, the first abutting surface A 311 and the second abutting surface A 221 abut each other, at this time, the first elastic member 70 is in the energy storage 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 the braking state, the roller 61 extends out under the action of the sliding unit 60 and contacts the outer contour of the auxiliary cam 11, and the abutment between the first abutting surface A 311 and the second abutting surface A 221 is released, and as the roller 61 alternately passes through the auxiliary cam 11 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 A surface 311 does not contact the second abutting A surface 221, and the first abutting B surface 312 does not contact the second abutting B surface 222. When the engine braking is completed and it turns 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, and the first abutting A surface 311 abuts the second abutting A surface 221 again.

[0078] Preferably, the return spring bracket 50 is arranged in a plate shape, and a first mounting hole 51 which is plug-fitted with a fastener and mounts the return spring bracket 50 on the rocker arm support 40 is arranged at one end of the return spring bracket 50, and a boss 52 is arranged at the other end of the return spring bracket 50, wherein an interference fit is formed between the boss 52 and the first elastic member 70, and the end of the first elastic member 70 which 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 boss 52 formed in this way is elastic and can form tension on the first elastic member 70, thereby completing the interference connection between the return spring bracket 50 and the first elastic member 70 and ensuring that the two are not separated, thereby improving the reliability of the connection between the two.

[0080] 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 shaft 30, and the horizontal height of the connection position between the return spring bracket 50 and the rocker 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 , wherein the first mounting hole 51 on the return spring bracket 50 is connected to the connecting hole 412 via 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 shaft 30 toward 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, wherein 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 shaft 30, a first mounting plane 321 for connecting the return spring bracket 50 is provided on the rocker shaft 30, and the first mounting plane 321 is formed by the downward depression of the arc surface of the rocker shaft 30, because in this way the position of the return spring bracket 50 on the first mounting plane 321 can be controlled to avoid relative slippage between the two when the two are connected, thereby improving the reliability of the connection between the two.

[0084] It is further pointed out that the first mounting planes 321 are provided at both ends of the rocker arm shaft 30 along the axial direction thereof, 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, the first mounting plane 321 is provided at each end of the rocker arm shaft 30 in order to achieve 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, so that the rocker arm shaft 30 is truly "symmetrically arranged" to ensure the efficiency of the assembly of the engine brake device.

[0086] Preferably, a positioning portion 211 is provided on the abutment platform 21, and the positioning portion 211 is nested with the first elastic member 70, and the radial freedom of the first elastic member 70 is limited by the positioning portion 211, wherein the positioning portion 211 is a concave cavity, or a positioning protrusion, wherein 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 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 abutment 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 axial direction of the first elastic member 70 during the stretching or compression process without twisting or deflecting.

[0088] In addition, a positioning portion 211 is provided on the abutting platform 21. 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 a concave cavity or a positioning protrusion, wherein the concave cavity refers to a cavity whose cavity mouth 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 configured to be circular, and the first elastic member 70 here is a cylindrical spring, which is generally also configured to be circular.

[0090] It is further pointed out that the positioning portion 211 is not limited to being integrally formed on the abutting platform 21 , but may 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] like Figures 1 to 12As shown, compared with the first embodiment, the difference between the present embodiment and the first embodiment is that the first elastic member 70 in the first embodiment is a columnar elastic member, while the second elastic member 80 in the present embodiment is a plate-shaped elastic member. Therefore, in the first embodiment, it is clearly pointed out that a return spring bracket 50 is added for the installation of the columnar elastic member, and one end of the return spring bracket 50 is connected to the first connecting portion 41 or the second connecting portion 32 on the rocker arm shaft 30 through a fastener, wherein 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 arm 20.

[0093] In the present embodiment, the return spring bracket 50 is not provided. Therefore, with regard to the installation of the plate-like elastic member, it is clearly pointed out that one end of the second elastic member 80 is connected to the first connecting portion 41 or the second connecting portion 32 on the rocker arm shaft 30 via a fastener, wherein 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 abutment platform 21, and the horizontal height of the end of the second elastic member 80 abutting against the abutment platform 21 is lower than the horizontal height of the upper surface of the braking rocker arm 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 higher than the horizontal heights of the abutment 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 lower than the horizontal heights of the abutment platform 21.

[0095] Regardless of whether it is the engine braking device in the first embodiment or the engine braking device in the second embodiment, the overall vertical dimension of the engine braking device can be reduced, making the structure more compact.

[0096] It is further pointed out that the second elastic member 80 is arranged in a Z-shaped plate shape, and the two ends of the second elastic member 80 are respectively a first connecting end 81 and a second connecting end 82, wherein the first connecting end 81 forms a surface-to-surface contact with the second mounting plane on the rocker shaft 30 and is connected and fixed by fasteners, and the second connecting end 82 forms a surface-to-surface contact with the abutment platform 21, wherein a fourth mounting hole is arranged on the second mounting plane.

[0097] In this embodiment, the second elastic member 80 is configured as a plate-like structure so that the second elastic member 80 is in surface contact with the abutment platform 21 and in surface contact with the second mounting plane. By increasing the contact area, the connection firmness and reliability of the second elastic member 80 are improved.

[0098] It is further pointed out that the structure of the second mounting plane and the fourth mounting hole arranged on the second mounting plane is the same as the structure of the first mounting plane 321 and the second mounting hole 322 arranged 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.

[0099] It is further pointed out that in addition to direct surface-to-surface contact between the abutment platform 21 and the second connecting end 82 of the second elastic member 80, a positioning protrusion or a positioning recess may be provided on the abutment platform 21, and a corresponding positioning recess or a positioning protrusion may be provided on the second connecting end 82 of the second elastic member 80, wherein the relative sliding between the abutment platform 21 and the second connecting end 82 of the second elastic member 80 is limited by the concave-convex cooperation between the positioning protrusion and the positioning recess.

[0100] It is worth mentioning that the role of the positioning protrusion and the positioning recess provided on the abutting platform 21 and the second elastic member 80 is the same as the role of the positioning portion 211 provided in the first embodiment, and therefore, it will not be described in detail here.

[0101] It should be noted that in the present invention, descriptions such as "first", "second", "one", etc. are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "multiple" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined. The terms "connected", "fixed", etc. should be understood in a broad sense. For example, "fixed" can be a fixed connection, a detachable connection, or an integral whole; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to the 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 ordinary technicians in the field can implement it. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0103] The specific embodiments described herein are merely examples of the spirit of the present invention. Those skilled in the art may make various modifications or additions to the specific embodiments described or replace them in similar ways, but they 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 of a base circle on the auxiliary cam is greater than a distance between the non-working surface and a center 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 cam shaft, wherein the side portion of the brake rocker arm extends in a horizontal direction to form an abutment platform, and 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 matched with the limiting recess is provided on the brake rocker arm, 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; The rocker arm support has two ends 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 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 is slidably connected to an 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 cam shaft; 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. As the working surface and the non-working surface on the auxiliary cam contact the roller alternately, the brake rocker arm swings back and forth around the rocker arm shaft, and the limiting protrusion swings back and forth in the limiting concave portion.

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 abutting A surface, the first abutting B surface, the second abutting A surface and the second abutting 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 which is plugged into and cooperates with a fastener and installs the return spring bracket on the rocker arm support is arranged at one end of the return spring bracket, 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 which cooperates 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, which is plugged into and matched with the fastener and mounts the return spring bracket on the rocker shaft. 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 that cooperates 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 through 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 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 rocker arm shaft is provided with first mounting planes at both ends 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. 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 of a base circle on the auxiliary cam is greater than a distance between the non-working surface and a center 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 cam shaft, wherein the side portion of the brake rocker arm extends in a horizontal direction to form an abutment platform, and 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 matched with the limiting recess is provided on the brake rocker arm, 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; The rocker arm support has two ends 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 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 the abutment platform is lower than the level of the upper surface of the brake rocker arm; A sliding unit is slidably connected to an 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 cam 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 second elastic member is in a deformed state; 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 contact the roller alternately, the brake rocker arm swings back and forth around the rocker arm shaft, and the limiting protrusion swings back and forth in the limiting concave portion.

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 contact with the rocker arm shaft and is connected and fixed by a fastener, and the second connecting end forms a surface contact with the abutment 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 a 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 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 second mounting planes at both ends along the axial direction thereof, and the second mounting 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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