An engine braking device with a return function and an engine

Abstract

The present invention provides a engine braking device with a return function and an engine, belonging to the technical field of automotive parts, including: a camshaft, including an auxiliary cam, with its non-working surface and working surface; a braking rocker arm and a rocker arm shaft, and a limiting portion is provided on the braking rocker arm; a movable unit, including a sliding portion and a rolling portion; 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, and the other end is provided with a return spring seat; an elastic member, arranged horizontally and clamped between the return spring seat and the limiting portion; wherein, when the engine brakes and the rolling portion contacts the non-working surface, the distance between the return spring seat and the limiting portion is the smallest; when the engine brakes and the rolling portion contacts the working surface, the distance between the return spring seat and the limiting portion is the largest. The present invention arranges the elastic member horizontally, thereby overall reducing the overall size of the entire engine braking device in the vertical direction.

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 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 force 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, including a movable unit 40 and a control mechanism. The movable unit 40 is movably arranged at the rear end of the auxiliary rocker arm and corresponds to the auxiliary cam 11; the control mechanism can drive the movable unit 40 to act, so that the movable unit 40 has a first position in contact with the auxiliary cam 11 and a second position separated from the auxiliary cam 11.

[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 function, including:

[0007] A camshaft, which 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 braking rocker arm and a rocker arm shaft that are in shaft-hole fit, and a limiting portion is provided on the braking rocker arm. Among them, the axis direction of the rocker arm shaft is parallel to the axis direction of the camshaft;

[0009] The active unit includes a sliding part slidably connected to one end of the braking rocker arm and a rolling part connected to the sliding part. The movement of the sliding part causes a gap between the rolling part and the working surface on the outer contour of the auxiliary cam or the rolling part to contact the outer contour of the auxiliary cam. The axial direction of the rolling part is parallel to the axial direction of the camshaft.

[0010] The rocker arm support has its two ends respectively in shaft hole fits with the camshaft and the rocker arm shaft, and a first connecting part is provided on the rocker arm support.

[0011] The return spring support has one end connected to the first connecting part and a return spring seat provided at the other end. The return spring seat is disposed opposite to the limiting part. The rotation of the braking rocker arm in the direction close to the camshaft is limited by the return spring seat.

[0012] The elastic member is horizontally arranged and clamped between the return spring seat and the limiting part. One end of the elastic member is connected to the return spring seat, and the other end of the elastic member abuts against the limiting part. The direction in which the elastic member is compressed or released is the same as the swinging direction of the braking rocker arm.

[0013] When the engine is operating normally, there is a gap between the rolling part and the working surface of the auxiliary cam, and the elastic member is in a compressed energy storage state.

[0014] When engine braking is performed, the rolling part contacts the outer contour of the auxiliary cam. As the working surface and the non - working surface on the auxiliary cam alternately contact the rolling part, the braking rocker arm swings reciprocally around the rocker arm shaft. When the rolling part contacts the non - working surface, the distance between the return spring seat and the limiting part is the smallest; when the rolling part contacts the working surface, the distance between the return spring seat and the limiting part is the largest.

[0015] In the above - mentioned engine braking device with a return function, the limiting part includes a first concave cavity provided on the braking rocker arm. The opening of the first concave cavity faces away from the position where the rocker arm shaft is located. The first concave cavity includes a first cavity wall and a second cavity wall. The return spring seat abuts against the second cavity wall, and the elastic member abuts against the first cavity wall. When engine braking is performed and the rolling part contacts the non - working surface, the return spring seat abuts against the second cavity wall; when engine braking is performed and the rolling part contacts the working surface, the return spring seat is separated from the second cavity wall.

[0016] In the above - mentioned engine braking device with a return function, a raised part is provided on the return spring support, and a second concave cavity is provided on the raised part. The position of the second concave cavity is opposite to the position of the first concave cavity, and the opening direction of the second concave cavity is opposite to the opening direction of the first concave cavity. The second concave cavity and the first concave cavity are spliced into a closed cavity, and the elastic member is located in the closed cavity. There is a gap between the bottom of the second concave cavity and the plane where the opening of the first concave cavity is located.

[0017] In the above-described engine braking device with a return function, the second concave cavity and the first concave cavity are integrally provided on the brake rocker arm, wherein the side portion of the limiting portion is provided with a closed structure.

[0018] In the above-described engine braking device with a return function, the return spring seat is connected to the edge of the raised portion, and on both sides of the return spring seat along the compression direction of the elastic member are respectively a first abutting surface and a second abutting surface, wherein the second abutting surface abuts against the second cavity wall, a positioning portion is provided on one side of the first abutting surface, and one end of the elastic member is nested and fixed with the positioning portion, and the other end of the elastic member abuts against the first cavity wall.

[0019] In the above-described engine braking device with a return function, the positioning portion is a convex platform or a groove. When the positioning portion is a convex platform, one end of the elastic member is sleeved on the convex platform and abuts against the first abutting surface; when the positioning portion is a groove, one end of the elastic member is embedded in the groove and abuts against the bottom of the groove.

[0020] In the above-described engine braking device with a return function, the number of rocker arm supports is two, and the two rocker arm supports are arranged at both ends of the camshaft along the axial direction of the camshaft, and a first connecting portion is provided on each of the two rocker arm supports. The return spring bracket is provided in a plate shape, and first connecting holes are provided at both ends of the return spring bracket. The two ends of the return spring bracket are respectively connected to the two first connecting portions by fasteners passing through the first connecting holes, and both sides of the open end of the second concave cavity are respectively located on both sides of the brake rocker arm.

[0021] In the above-described engine braking device with a return function, the first connecting portion includes a support bolt screwed on the rocker arm support, and the return spring bracket abuts against one end of the support bolt, and the connection between the return spring bracket and the support bolt is completed by fasteners.

[0022] The present invention also provides an engine braking device with a return function, including:

[0023] 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;

[0024] A brake rocker arm and a rocker arm shaft that are in shaft-hole fit, and a limiting portion is provided on the brake rocker arm, wherein the axial direction of the rocker arm shaft is parallel to the axial direction of the camshaft, and a second connecting portion is provided on the rocker arm shaft;

[0025] The active unit includes a sliding part slidably connected to one end of the brake rocker arm and a rolling part connected to the sliding part. The movement of the sliding part causes a gap between the rolling part and the working surface on the outer contour of the auxiliary cam or the rolling part to contact the outer contour of the auxiliary cam. The axial direction of the rolling part is parallel to the axial direction of the camshaft;

[0026] The rocker arm support has its two ends respectively in shaft hole fits with the camshaft and the rocker arm shaft;

[0027] The return spring support has one end connected to the second connecting part and the other end provided with a return spring seat, and the return spring seat is arranged opposite to the limiting part. The rotation of the brake rocker arm along the direction close to the camshaft is limited by the return spring seat;

[0028] The elastic member is arranged horizontally and clamped between the return spring seat and the limiting part. One end of the elastic member is connected to the return spring seat and the other end abuts against the limiting part. The direction in which the elastic member is compressed or released is consistent with the swinging direction of the brake rocker arm;

[0029] When the engine is operating normally, there is a gap between the rolling part and the working surface of the auxiliary cam, and the elastic member is in a compressed energy storage state;

[0030] When engine braking is performed, the rolling part contacts the outer contour of the auxiliary cam. As the working surface and the non - working surface on the auxiliary cam alternately contact the rolling part, the brake rocker arm swings reciprocally around the rocker arm shaft. When the rolling part contacts the non - working surface, the distance between the return spring seat and the limiting part is the smallest; when the rolling part contacts the working surface, the distance between the return spring seat and the limiting part is the largest.

[0031] In the above - mentioned engine braking device with a return function, the limiting part includes a first concave cavity provided on the brake rocker arm. The opening of the first concave cavity faces away from the position where the rocker arm shaft is located, and the first concave cavity includes a first cavity wall and a second cavity wall. The return spring seat abuts against the second cavity wall, and the elastic member abuts against the first cavity wall. When engine braking is performed and the rolling part contacts the non - working surface, the return spring seat abuts against the second cavity wall; when engine braking is performed and the rolling part contacts the working surface, the return spring seat separates from the second cavity wall.

[0032] In the above - mentioned engine braking device with a return function, a raised part is provided on the return spring support, and a second concave cavity is provided on the raised part. The position of the second concave cavity is arranged opposite to the position of the first concave cavity, and the opening direction of the second concave cavity is opposite to the opening direction of the first concave cavity. The second concave cavity and the first concave cavity are spliced into a closed cavity, and the elastic member is located in the closed cavity. There is a gap between the bottom of the second concave cavity and the plane where the opening of the first concave cavity is located.

[0033] In the above-described engine braking device with a return function, the second concave cavity and the first concave cavity are integrally arranged on the braking rocker arm, wherein the side portion of the limiting portion is arranged in a closed structure.

[0034] In the above-described engine braking device with a return function, the number of the second connecting portions is two, and the two second connecting portions are distributed at both ends of the rocker shaft along the axial direction of the rocker shaft. The return spring bracket is arranged in a plate shape, and a first connecting hole is provided at each end of the return spring bracket. The two ends of the return spring bracket are respectively connected to the two second connecting portions by fasteners passing through the first connecting holes, and both sides of the opening end of the second concave cavity are respectively located on both sides of the braking rocker arm.

[0035] In the above-described engine braking device with a return function, the second connecting portion includes a mounting plane, and a second connecting hole is provided on the mounting plane. The return spring bracket is screwed into the second connecting hole through a fastener.

[0036] In the above-described engine braking device with a return function, the number of the second connecting holes is two, and the two second connecting holes are arranged side by side.

[0037] The present invention further provides an engine, which is characterized by including the above-described engine braking device with a return function.

[0038] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0039] (1) For the engine braking device with a return function provided by the present invention, the elastic member is arranged horizontally, so as to overall reduce the overall size of the entire engine braking device in the vertical direction, avoid the situation of being unable to install or colliding with other components in the engine after installation. In addition, by providing the limiting portion, the relative gap between the rolling portion and the camshaft during the normal operation of the engine can be accurately controlled, the friction work can be reduced, the fuel consumption of the entire engine can be reduced, and the setting of the limiting portion can prevent the elastic member from twisting or bending when being compressed or released, thereby improving the braking effect of the engine braking device.

[0040] (2) The limiting portion is arranged in a concave cavity structure, and the elastic member is horizontally arranged in the concave cavity structure, and both ends of the elastic member are clamped between the first cavity wall and the return spring seat, indirectly clamped between the first cavity wall and the second cavity wall, so as to improve the straightness of the elastic member when being compressed or released.

[0041] (3) By providing a positioning portion on the return spring seat, the radial degree of freedom of the elastic member during movement can be limited, preventing relative slippage between the elastic member and the return spring seat when the elastic member is compressed or released. Additionally, the positioning portion can also serve as a connection and fixation between the elastic member and the return spring seat, enabling the return spring bracket and the elastic member to form a "whole", thereby improving the assembly efficiency of the engine braking device. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 FIG. is a schematic structural diagram of an engine braking device with a return function according to the present invention.

[0043] Figure 2 FIG. is a schematic structural diagram of another perspective of an engine braking device with a return function according to the present invention.

[0044] Figure 3 FIG. is a schematic structural diagram of a braking rocker arm in a preferred embodiment of the present invention.

[0045] Figure 4 FIG. is a sectional view of an engine braking device with a return function according to the present invention during normal engine operation.

[0046] Figure 5 FIG. is a sectional view of an engine braking device with a return function according to the present invention during engine braking.

[0047] Figure 6 FIG. is an assembly diagram of a return spring bracket, a return spring seat, and an elastic member in a preferred embodiment of the present invention.

[0048] Figure 7 FIG. is a schematic structural diagram of a return spring bracket in a preferred embodiment of the present invention.

[0049] Figure 8 FIG. is a schematic structural diagram of a return spring seat in a preferred embodiment of the present invention.

[0050] Figure 9 FIG. is a schematic structural diagram of another perspective of a return spring seat in a preferred embodiment of the present invention.

[0051] In the figures,

[0052] 10. Camshaft; 11. Auxiliary cam; 111. Non-working surface; 112. Working surface;

[0053] 20. Braking rocker arm; 21. First cavity; 211. First cavity wall; 212. Second cavity wall;

[0054] 30. Rocker arm shaft; 31. Second connecting portion; 311. Mounting plane; 312. Second connecting hole;

[0055] 40. Active unit; 41. Sliding part; 42. Rolling part;

[0056] 50. Rocker arm support; 51. First connecting part;

[0057] 60. Return spring support; 61. First connecting hole; 62. Second concave cavity;

[0058] 70. Return spring seat; 71. First abutting surface; 72. Second abutting surface; 73. Positioning part;

[0059] 80. Elastic part. Detailed implementation mode

[0060] The following are specific embodiments of the present invention and in combination with the accompanying drawings, the technical solutions of the present invention are further described, but the present invention is not limited to these embodiments.

[0061] 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 position relationship and movement conditions between components in a specific posture (as shown in the accompanying drawings). If this specific posture changes, then the directional indications will also change accordingly.

[0062] As Figures 1 to 9 shown, a braking device for an engine with a return function provided by the present invention includes:

[0063] 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 on the auxiliary cam 11 is greater than the distance between the non-working surface 111 and the base circle center on the auxiliary cam 11;

[0064] A braking rocker arm 20 and a rocker arm shaft 30 that are shaft-hole matched, and a limiting part is provided on the braking rocker arm 20. Among them, the axial direction of the rocker arm shaft 30 is parallel to the axial direction of the camshaft 10;

[0065] An active unit 40, including a sliding part 41 slidably connected to one end of the braking rocker arm 20, and a rolling part 42 connected to the sliding part 41. And through the movement of the sliding part 41, there is a gap between the rolling part 42 and the working surface 112 on the outer contour of the auxiliary cam 11, or it is in contact with the outer contour of the auxiliary cam 11. Among them, the axial direction of the rolling part 42 is parallel to the axial direction of the camshaft 10;

[0066] A rocker arm support 50, the two ends are respectively shaft-hole matched with the camshaft 10 and the rocker arm shaft 30, and a first connecting part 51 is provided on the rocker arm support 50;

[0067] The return spring bracket 60 has one end connected to the first connection portion 51, and a return spring seat 70 is provided at the other end. The return spring seat 70 is disposed opposite to the limiting portion. Among them, the rotation of the brake rocker arm 20 along the direction close to the camshaft 10 is limited by the return spring seat 70;

[0068] The elastic member 80 is arranged horizontally and is clamped between the return spring seat 70 and the limiting portion. One end of the elastic member 80 is connected to the return spring seat 70, and the other end of the elastic member 80 abuts against the limiting portion. Among them, the direction in which the elastic member 80 is compressed or released is the same as the swinging direction of the brake rocker arm;

[0069] Among them, when the engine is working normally, there is a gap between the rolling portion 42 and the working surface 112 of the auxiliary cam 11, and the elastic member 80 is in a compressed energy storage state;

[0070] When engine braking is performed, the rolling portion 42 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 rolling portion 42, the brake rocker arm 20 swings reciprocally around the rocker arm shaft 30. When the rolling portion 42 contacts the non-working surface 111, the distance between the return spring seat 70 and the limiting portion is the smallest; when the rolling portion 42 contacts the working surface 112, the distance between the return spring seat 70 and the limiting portion is the largest.

[0071] In the prior art, the elastic member 80 connected to the return spring bracket 60 is arranged vertically. Such a structural arrangement makes the overall size of the entire engine braking device larger in the vertical direction, which may cause the engine braking device to collide with the engine hood after assembly, or may cause the engine braking device to be unable to be installed.

[0072] However, for an engine braking device with a return function provided by the present invention, the elastic member 80 is arranged horizontally, thereby reducing the overall size of the entire engine braking device in the vertical direction as a whole, avoiding the situation of being unable to be installed or colliding with other components in the engine after installation. In addition, by providing the limiting portion, the relative gap between the rolling portion 42 and the camshaft 10 during normal operation of the engine can be accurately controlled, the frictional work can be reduced, and the fuel consumption of the entire engine can be reduced. Moreover, the setting of the limiting portion can prevent the elastic member 80 from being twisted or bent when being compressed or released, thereby improving the braking effect of the engine braking device.

[0073] It is worth mentioning that, as can be seen from the description of the above embodiments, one end of the return spring bracket 60 is connected to the first connection portion 51 of the rocker arm support 50 through a fastener. Similarly, one end of the return spring bracket 60 can be connected to the second connection portion 31 of the rocker arm shaft 30 through a fastener. The reason why the return spring bracket 60 can be connected to the rocker arm support 50 or the rocker arm shaft 30 is that when the engine is in engine braking, the braking rocker arm 20 is in a moving state, while the return spring bracket 60 is in a static state. In the engine braking device, whether the engine is in normal operation or in the braking state, the rocker arm support 50 and the rocker arm shaft 30 are both in a static state. Therefore, the return spring bracket 60 can be in a static state by being connected to the rocker arm support 50 or the rocker arm shaft 30.

[0074] It is worth mentioning that the return spring seat 70 is connected to one end of the return spring bracket 60, and one end of the elastic member 80 is connected to the return spring seat 70. When the engine is in the braking state, the elastic member 80 is in a process of being continuously compressed or released. During the compression or release process of the elastic member 80, it will continuously press or pull the return spring seat 70. Although the return spring bracket 60 is in a fixed state and the return spring seat 70 is connected to the return spring bracket 60 and is also in a fixed state, if it is only fixed by one end of the return spring bracket 60 (the end connected to the first connection portion 51 or the second connection portion 31), then the return spring bracket 60 will be in a structure similar to a "cantilever beam" after being fixed. Moreover, the return spring bracket 60 is arranged in a plate shape and is prone to "jitter" under the dynamic action of the elastic member 80, thereby affecting the braking effect of the engine braking device. Therefore, in order to prevent the return spring bracket 60 from "jittering" during the compression or release process of the elastic member 80, the return spring bracket 60 needs to be "reinforced". So, in this embodiment, when the return spring bracket 60 is connected to the rocker arm support 50, the number of rocker arm supports 50 is set to two, and the two rocker arm supports 50 are arranged at both ends of the camshaft 10 along the axial direction of the camshaft 10. Among them, a first connection portion 51 is provided on each of the two rocker arm supports 50, and the connection line of the two first connection portions 51 is parallel to the axis of the camshaft 10. In this way, both ends of the return spring bracket 60 are correspondingly connected to the two first connection portions 51, and the return spring seat 70 is arranged between both ends of the return spring bracket 60.

[0075] Similarly, when the return spring bracket 60 is connected to the rocker arm shaft 30, the number of the second connection portions 31 is two, and they are arranged at both ends of the rocker arm shaft 30 along the axial direction of the rocker arm shaft 30. Among them, both ends of the return spring bracket 60 are correspondingly connected to the two second connection portions 31, and the return spring seat 70 is arranged between both ends of the return spring bracket 60.

[0076] In addition, it is worth mentioning that when a first connecting portion 51 is provided on each rocker arm support 50, the types of the rocker arm supports 50 can be reduced, which is convenient for management; when second connecting portions 31 are provided at both ends of each rocker shaft 30, a foolproof design of the rocker shaft 30 can be achieved, and the assembly speed of the entire engine braking device can be accelerated.

[0077] Preferably, the first connecting portion 51 includes a support bolt screwed onto the rocker arm support 50, and first connecting holes 61 are provided at both ends of the return spring bracket 60. Wherein, by passing a fastener through the first connecting hole 61 and screwing it into the support bolt, the connection between the return spring bracket 60 and the rocker arm support 50 can be completed, and the disassembly and assembly are relatively convenient.

[0078] Preferably, the second connecting portion 31 includes an installation plane 311, and second connecting holes 312 are provided on the installation plane 311. Wherein, first connecting holes 61 are provided at both ends of the return spring bracket 60. By passing a fastener through the first connecting hole 61 and screwing it into the second connecting hole 312, the connection between the return spring bracket 60 and the rocker arm can be completed, and the disassembly and assembly are relatively convenient.

[0079] It is worth mentioning that when the return spring bracket 60 is connected to the rocker shaft 30, the second connecting holes 312 are not directly formed on the rocker shaft 30. Instead, the installation plane 311 is first provided on the rocker shaft 30, and then the second connecting holes 312 are provided on the installation plane 311. The advantage of this is that when the return spring bracket 60 is connected to the rocker shaft 30, the contact area between the return spring bracket 60 and the rocker shaft 30 is increased, thereby improving the reliability of the connection between the two. In addition, regarding the processing technology of the second connecting holes 312, comparing the processing of holes on a "curved surface" and on a "plane", it is more convenient to process on a "plane", and the processing of the hole diameter is more accurate.

[0080] Further preferably, the number of the second connecting holes 312 in each second connecting portion 31 is two, and the two second connecting holes 312 are arranged side by side, so as to be able to adapt to the sizes of different return spring brackets 60 and improve the flexibility of the connection of the return spring brackets 60.

[0081] In addition, by providing two second connection holes 312, it is also possible to achieve a "misaligned connection" when the return spring bracket 60 is connected to the second connection holes 312, rather than a "symmetrical connection". Here, "misaligned connection" means that one end of the return spring bracket 60 is connected to the second connection hole 312 near one end of the rocker shaft 30, and the other end is connected to the second connection hole 312 far from the other end of the rocker shaft 30; "symmetrical connection" means that both ends of the return spring bracket 60 are simultaneously connected to the second connection hole 312 near the corresponding end of the rocker shaft 30, or simultaneously connected to the second connection hole 312 far from the corresponding end of the rocker shaft 30.

[0082] Preferably, the limiting portion includes a first concave cavity 21 provided on the brake rocker 20. The opening of the first concave cavity 21 faces away from the position where the rocker shaft 30 is located, and the first concave cavity 21 includes a first cavity wall 211 and a second cavity wall 212. Here, the return spring seat 70 abuts against the second cavity wall 212, and the elastic member 80 abuts against the first cavity wall 211. When engine braking occurs and the rolling portion 42 contacts the non-working surface 111, the return spring seat 70 abuts against the second cavity wall 212; when engine braking occurs and the rolling portion 42 contacts the working surface 112, the return spring seat 70 separates from the second cavity wall 212.

[0083] It is worth mentioning that as shown in the figure, when the engine is operating normally, the elastic member 80 is in an energy storage state and can cause the brake rocker 20 to rotate counterclockwise in the direction close to the camshaft 10. Due to the abutment between the return spring seat 70 and the second cavity wall 212, the rotation angle of the brake rocker 20 can be limited, so that when the moving unit 40 on the brake rocker 20 is not extended, there is a gap between the rolling portion 42 connected to the moving unit 40 and the working surface 112 of the auxiliary cam 11, and the size of this gap can be strictly controlled; when engine braking occurs, the moving unit 40 extends and the rolling portion 42 contacts the outer contour of the auxiliary cam 11. By continuously passing the rolling portion 42 through the working surface 112 and the non-working surface 111 of the auxiliary cam 11, the return spring seat 70 continuously contacts or separates from the second cavity wall 212, and at the same time, the elastic member 80 is continuously compressed or released.

[0084] In this embodiment, the limiting portion is arranged in a concave cavity structure, and the elastic member 80 is horizontally arranged in the concave cavity structure, and both ends of the elastic member 80 are clamped between the first cavity wall 211 and the return spring seat 70, indirectly clamped between the first cavity wall 211 and the second cavity wall 212, thereby improving the straightness of the elastic member 80 when it is compressed or released.

[0085] In addition, the two sides of the opening of the first concave cavity 21 can be made of equal height, or there can be a height difference between the two, which is acceptable and there is no strict limitation on it.

[0086] It is worth mentioning that the limiting portion is integrally provided with the brake swing arm 20.

[0087] Preferably, a raised portion is provided on the return spring bracket 60, and a second concave cavity 62 is provided on the raised portion. Among them, the position of the second concave cavity 62 is opposite to the position of the first concave cavity 21, and the opening direction of the second concave cavity 62 is opposite to the opening direction of the first concave cavity 21. A closed cavity is formed by splicing the second concave cavity 62 and the first concave cavity 21, and the elastic member 80 is located in the closed cavity. There is a gap between the bottom of the second concave cavity 62 and the plane where the orifice of the first concave cavity 21 is located.

[0088] It is worth mentioning that the first concave cavity 21 on the brake swing arm 20 is U-shaped, that is, a first cavity wall 211 and a second cavity wall 212 are provided in the reciprocating swing direction of the brake swing arm 20, and no corresponding cavity walls are provided on both sides along the axis direction of the swing arm shaft 30. Therefore, in order to prevent the elastic member 80 from "running out" of the first concave cavity 21 during the process of being compressed or released, a second concave cavity 62 is provided on the return spring bracket 60, and the position of the second concave cavity 62 corresponds to the position of the first concave cavity 21. Among them, the opening direction of the second concave cavity 62 is opposite to the opening direction of the first concave cavity 21, and the two form a relationship similar to "interlocking". The two cavity walls on the cavity wall of the second concave cavity 62 are arranged along the axis direction of the swing arm shaft 30, so that the position where the elastic member 80 is located is spliced into a closed cavity by the first concave cavity 21 and the second concave cavity 62, thereby avoiding the risk of the elastic member 80 being "run out".

[0089] In addition, there is another way, that is, the two cavity walls of the second concave cavity 62 are also provided on the brake swing arm 20, so that the side part of the first concave cavity 21 on the brake swing arm 20 is a closed structure, and the second concave cavity 62 is not provided on the return spring bracket 60. Such a setting can also achieve the "full enclosure" of the elastic member 80 and improve the reliability of the elastic member 80 during use.

[0090] Preferably, the return spring seat 70 is connected to the edge of the raised portion, and on both sides of the return spring seat 70 along the compression direction of the elastic member 80 are a first abutting surface 71 and a second abutting surface 72 respectively. Among them, the second abutting surface 72 abuts against the second cavity wall 212, a positioning portion 73 is provided on one side of the first abutting surface 71, and one end of the elastic member 80 is nested and fixed with the positioning portion 73, and the other end of the elastic member 80 abuts against the first cavity wall 211.

[0091] In this embodiment, by providing a positioning portion 73 on the return spring seat 70, the radial degree of freedom of the elastic member 80 during movement can be limited, preventing relative slippage between the elastic member 80 and the return spring seat 70 when the elastic member 80 is compressed or released. Additionally, the provision of the positioning portion 73 can also serve as the connection and fixation between the elastic member 80 and the return spring seat 70, enabling the return spring bracket 60 and the elastic member 80 to form an "integral body", thereby improving the assembly efficiency of the engine braking device.

[0092] It is worth mentioning that the positioning portion 73 is a boss or a groove. When the positioning portion 73 is a boss, one end of the elastic member 80 is sleeved on the boss and abuts against the first abutting surface 71; when the positioning portion 73 is a groove, one end of the elastic member 80 is embedded in the groove and abuts against the bottom of the groove.

[0093] In addition, the return spring bracket 60 is provided in a plate shape, and multiple bends are provided on the return spring bracket 60 to improve the strength of the entire return spring bracket 60. Among them, the return spring seat 70 and the return spring bracket 60 are connected by welding, or the return spring seat 70 is formed by bending the edge of the return spring bracket 60. Both of the above two methods are acceptable, but are not limited to the two methods described above.

[0094] It should be noted that in the present invention, descriptions such as "first", "second", and "one" are only for descriptive purposes and should not be construed as indicating or implying their relative importance or implicitly specifying the quantity of the indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include at least one of such features. In the description of the present invention, the meaning of "a plurality" is at least two, such as two, three, etc., unless otherwise specifically defined. Terms such as "connection" and "fixation" should be understood in a broad sense. For example, "fixation" can be a fixed connection, a detachable connection, or an integral body; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and can be the internal communication of two components or the interaction relationship between two components, 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.

[0095] 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 ability of those of ordinary skill in the art to implement. 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 scope of protection required by the present invention.

[0096] The specific embodiments described herein are merely illustrative of the spirit of the present invention. Those skilled in the art to which the present invention pertains can make various modifications or supplements to the described specific embodiments or use similar ways for substitution, without departing from the spirit of the present invention or exceeding the scope defined by the appended claims.

Claims

1. An engine brake device with a return function, 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 the shaft hole, and a limit portion is arranged on the brake rocker arm, wherein the axial direction of the rocker arm shaft is parallel to the axial direction of the cam shaft; The movable unit comprises a sliding part slidably connected to one end of the brake rocker arm, and a rolling part connected to the sliding part, and the sliding part moves so that a gap exists between the rolling part and a working surface on the outer contour of the auxiliary cam, or the rolling part contacts the outer contour of the auxiliary cam, wherein the axial direction of the rolling part is parallel to the axial direction of the cam shaft; The rocker arm support has two ends respectively matched with the camshaft and the rocker arm shaft holes, and a first connecting portion is provided on the rocker arm support; A return spring bracket, one end of which is connected to the first connecting portion, and the other end of which is provided with a return spring seat, and the return spring seat is arranged opposite to the limiting portion, wherein the brake rocker arm is limited to rotate in a direction close to the camshaft by the return spring seat; The elastic member is arranged in a transverse direction and clamped between the return spring seat and the limiting portion, and one end of the elastic member is connected to the return spring seat, and the other end of the elastic member is in contact with the limiting portion, wherein the direction in which the elastic member is compressed or released is consistent with the swing direction of the brake rocker arm; When the engine is working normally, there is a gap between the rolling part and the working surface of the auxiliary cam, and the elastic member is in a compressed energy storage state; When the engine brakes, the rolling part contacts the outer contour of the auxiliary cam, and as the working surface and the non-working surface on the auxiliary cam contact the rolling part alternately, the brake rocker arm swings back and forth around the rocker arm shaft. When the rolling part contacts the non-working surface, the distance between the return spring seat and the limiting part is the smallest; when the rolling part contacts the working surface, the distance between the return spring seat and the limiting part is the largest. The limiting portion includes a first concave cavity arranged on the braking rocker arm, the cavity mouth of the first concave cavity is away from the position where the rocker arm shaft is located, and the first concave cavity includes a first cavity wall and a second cavity wall, wherein the return spring seat abuts against the second cavity wall, and the elastic member abuts against the first cavity wall. When the engine brakes and the rolling portion contacts the non-working surface, the return spring seat abuts against the second cavity wall; when the engine brakes and the rolling portion contacts the working surface, the return spring seat is separated from the second cavity wall.

2. The engine brake device with return function according to claim 1, characterized in that: A raised portion is provided on the return spring bracket, and a second concave cavity is provided on the raised portion, wherein the position of the second concave cavity is arranged relative to the position of the first concave cavity, and the opening direction of the second concave cavity is opposite to the opening direction of the first concave cavity, and the second concave cavity and the first concave cavity are spliced ​​into a closed cavity, and the elastic member is located in the closed cavity, and there is a gap between the cavity bottom of the second concave cavity and the plane where the cavity opening of the first concave cavity is located.

3. The engine brake device with return function according to claim 2, characterized in that: The second cavity is integrated with the first cavity on the brake rocker arm, wherein the side portion of the limiting portion is arranged in a closed structure.

4. The engine brake device with return function according to claim 2, characterized in that: The return spring seat is connected to the edge of the raised portion, and the two sides of the return spring seat along the compression direction of the elastic member are respectively a first abutting surface and a second abutting surface, wherein the second abutting surface abuts against the second cavity wall, a positioning portion is provided on one side of the first abutting surface, and one end of the elastic member is nested and fixed with the positioning portion, and the other end of the elastic member abuts against the first cavity wall.

5. The engine brake device with return function according to claim 4, characterized in that: The positioning portion is a boss or a groove. When the positioning portion is a boss, one end of the elastic member is placed on the boss and abuts against the first abutting surface; when the positioning portion is a groove, one end of the elastic member is embedded in the groove and abuts against the bottom of the groove.

6. The engine brake device with return function according to claim 3, characterized in that: There are two rocker arm supports, and the two rocker arm supports are arranged at both ends of the camshaft along the axial direction of the camshaft, and a first connecting part is arranged on each of the two rocker arm supports, wherein the return spring support is arranged in a plate shape, and a first connecting hole is arranged at each end of the return spring support, and the two ends of the return spring support are respectively connected to the two first connecting parts by fasteners passing through the first connecting holes, and the two sides of the opening end of the second concave cavity are respectively located on both sides of the brake rocker arm.

7. The engine brake device with return function according to claim 1, characterized in that: The first connecting part includes a supporting bolt screwed on the rocker arm support, and the return spring bracket is abutted against one end of the supporting bolt, and the connection between the return spring bracket and the supporting bolt is completed by a fastener.

8. An engine brake device with a return function, 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 shaft matched through the shaft hole, and a limit portion is provided on the brake rocker arm, wherein the axial direction of the rocker shaft is parallel to the axial direction of the camshaft, and a second connecting portion is provided on the rocker shaft; The movable unit comprises a sliding part slidably connected to one end of the brake rocker arm, and a rolling part connected to the sliding part, and the sliding part moves so that a gap exists between the rolling part and a working surface on the outer contour of the auxiliary cam, or the rolling part contacts the outer contour of the auxiliary cam, wherein the axial direction of the rolling part is parallel to the axial direction of the cam shaft; The rocker arm support has two ends respectively matched with the camshaft and the rocker arm shaft holes; A return spring bracket, one end of which is connected to the second connecting portion, and the other end of which is provided with a return spring seat, and the return spring seat is arranged opposite to the limiting portion, wherein the return spring seat limits the braking rocker arm to rotate in a direction close to the camshaft; The elastic member is arranged in a transverse direction and clamped between the return spring seat and the limiting portion, and one end of the elastic member is connected to the return spring seat, and the other end of the elastic member is in contact with the limiting portion, wherein the direction in which the elastic member is compressed or released is consistent with the swing direction of the brake rocker arm; When the engine is working normally, there is a gap between the rolling part and the working surface of the auxiliary cam, and the elastic member is in a compressed energy storage state; When the engine brakes, the rolling part contacts the outer contour of the auxiliary cam, and as the working surface and the non-working surface on the auxiliary cam contact the rolling part alternately, the brake rocker arm swings back and forth around the rocker arm shaft. When the rolling part contacts the non-working surface, the distance between the return spring seat and the limiting part is the smallest; when the rolling part contacts the working surface, the distance between the return spring seat and the limiting part is the largest. The limiting portion includes a first concave cavity arranged on the braking rocker arm, the cavity mouth of the first concave cavity is away from the position where the rocker arm shaft is located, and the first concave cavity includes a first cavity wall and a second cavity wall, wherein the return spring seat abuts against the second cavity wall, and the elastic member abuts against the first cavity wall. When the engine brakes and the rolling portion contacts the non-working surface, the return spring seat abuts against the second cavity wall; when the engine brakes and the rolling portion contacts the working surface, the return spring seat is separated from the second cavity wall.

9. The engine brake device with return function according to claim 8, characterized in that: A raised portion is provided on the return spring bracket, and a second concave cavity is provided on the raised portion, wherein the position of the second concave cavity is arranged relative to the position of the first concave cavity, and the opening direction of the second concave cavity is opposite to the opening direction of the first concave cavity, and the second concave cavity and the first concave cavity are spliced ​​into a closed cavity, and the elastic member is located in the closed cavity, and there is a gap between the cavity bottom of the second concave cavity and the plane where the cavity opening of the first concave cavity is located.

10. The engine brake device with return function according to claim 9, characterized in that: The second cavity is integrated with the first cavity on the brake rocker arm, wherein the side portion of the limiting portion is arranged in a closed structure.

11. The engine brake device with return function according to claim 9, characterized in that: There are two second connecting parts, and the two second connecting parts are distributed at both ends of the rocker arm shaft along the axial direction of the rocker arm shaft, wherein the return spring bracket is arranged in a plate shape, and a first connecting hole is arranged at each end of the return spring bracket, and the two ends of the return spring bracket are respectively connected to the two second connecting parts by fasteners passing through the first connecting holes, and the two sides of the opening end of the second concave cavity are respectively located on both sides of the braking rocker arm.

12. The engine brake device with return function according to claim 8, characterized in that: The second connecting portion includes a mounting plane, and a second connecting hole is arranged on the mounting plane, wherein the fastener is screwed into the second connecting hole through the return spring bracket.

13. The engine brake device with return function according to claim 12, characterized in that: The number of the second connection holes is two, and the two second connection holes are arranged side by side.

14. An engine, characterized in that: include: An engine braking device with a return function as claimed in claim 1 or 8.

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