Engine braking device having return function, and engine

Abstract

An engine braking device having a return function, and an engine. The engine braking device comprises: a camshaft (10), comprising an auxiliary cam (11) having a non-working surface (111) and a working surface (112) thereon; a brake rocker arm (20) and a rocker arm shaft (30), the brake rocker arm (20) being provided with a limiting portion thereon; a movable unit (40), comprising a sliding portion (41) and a rolling portion (42); a rocker arm support (50), provided with a first connection portion (51); a return spring bracket (60), one end thereof being connected to the first connection portion (51), and the other end thereof being provided with a return spring seat (70); and an elastic member (80), arranged transversely and clamped between the return spring seat (70) and the limiting portion. During engine braking, when the rolling portion (42) is in contact with the non-working surface (111), the distance between the return spring seat (70) and the limiting portion is minimal; and during engine braking, when the rolling portion (42) is in contact with the working surface (112), the distance between the return spring seat (70) and the limiting portion is maximal. In said engine, the elastic member (80) is arranged transversely, thereby reducing the overall vertical dimension of the entire engine braking device.

Description

An engine braking device with return function and an engine Technical Field

[0001] This invention belongs to the field of automotive parts technology, and relates to an engine braking device, particularly an engine braking device and engine with a return function. Background Technology

[0002] Engine braking technology refers to the braking effect on a vehicle caused by the driver releasing the accelerator pedal and clutch during driving. This effect utilizes the compression resistance generated during the engine's compression stroke, along with intake and exhaust resistance and friction, to apply braking force to the drive wheels. Engine braking effectively reduces the frequency of use of the service brakes. When driving down long slopes or on steep roads such as rugged mountain roads, using engine braking can prevent the brake pads from overheating due to prolonged brake use, which could lead to a decrease in braking force or even complete loss of effectiveness.

[0003] Patent application (CN202110941484.X) discloses an energy-saving and consumption-reducing engine braking device, including a movable unit 40 and a control mechanism. The movable unit 40 is movably disposed 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 move, so that the movable unit 40 has a first position that is in contact with the auxiliary cam 11 and a second position that is separated from the auxiliary cam 11.

[0004] Although the aforementioned engine braking device achieves energy saving and consumption reduction, the entire engine braking device is relatively large in the vertical direction. After installation, there is a possibility of collision with the engine cover, which may affect the engine braking effect. Technical issues

[0005] The purpose of this invention is to address the aforementioned problems in existing technologies by proposing an engine braking device that can effectively reduce vertical dimensions while ensuring braking performance. Technical solutions

[0006] The objective of this invention can be achieved through the following technical solution: an engine braking device with a return function, comprising:

[0007] A camshaft, including an auxiliary cam, and having a non-working surface and a working surface on the outer contour of the auxiliary cam, wherein the distance between the working surface and the center of the base circle of the auxiliary cam is greater than the distance between the non-working surface and the center of the base circle of the auxiliary cam;

[0008] The braking rocker arm and rocker arm shaft are fitted by a shaft hole, and a limiting part is provided on the braking rocker arm. The axial direction of the rocker arm shaft is parallel to the axial direction of the cam shaft.

[0009] The movable unit includes a sliding part that slides onto one end of the brake rocker arm and a rolling part connected to the sliding part. The movement of the sliding part causes the rolling part to have a gap with the working surface on the outer contour of the auxiliary cam, or 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 two ends that mate with the camshaft and the rocker arm shaft holes respectively, and a first connecting part is provided on the rocker arm support;

[0011] The return spring bracket has one end connected to the first connecting part and the other end provided with a return spring seat, which is disposed opposite to the limiting part. The rocker arm is restricted to rotate in the direction close to the camshaft by the return spring seat.

[0012] The elastic element is arranged laterally and is sandwiched between the return spring seat and the limiting part. One end of the elastic element is connected to the return spring seat, and the other end of the elastic element abuts against the limiting part. The direction in which the elastic element is compressed or released is consistent with the swing direction of the brake rocker arm.

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

[0014] When the engine brakes, the rolling part contacts the outer contour of the auxiliary cam. As the working surface and non-working surface on the auxiliary cam alternately contact the rolling part, the brake rocker arm swings back and forth around the rocker arm axis. When the rolling part contacts the non-working surface, the distance between the return spring seat and the limit part is the smallest; when the rolling part contacts the working surface, the distance between the return spring seat and the limit part is the largest.

[0015] In the aforementioned engine braking device with a return function, the limiting part includes a first cavity disposed on the brake rocker arm. The opening of the first cavity is away from the position of the rocker arm shaft, and the first cavity includes a first cavity wall and a second cavity wall. The return spring seat abuts against the second cavity wall, and the elastic element abuts against the first cavity wall. When the engine brakes and the rolling part contacts the non-working surface, the return spring seat abuts against the second cavity wall; when the engine brakes and the rolling part contacts the working surface, the return spring seat separates from the second cavity wall.

[0016] In the aforementioned engine braking device with a return function, a raised portion is provided on the return spring bracket, and a second recess is provided on the raised portion. The position of the second recess is opposite to that of the first recess, and the opening direction of the second recess is opposite to that of the first recess. The second recess and the first recess are joined together to form a closed cavity, and the elastic element is located in the closed cavity. There is a gap between the bottom of the second recess and the plane where the opening of the first recess is located.

[0017] In the aforementioned engine braking device with return function, the second cavity and the first cavity are integrated on the brake rocker arm, wherein the side of the limiting part is provided with a closed structure.

[0018] In the aforementioned engine braking device with a return function, 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 the first abutment surface and the second abutment surface. The second abutment surface abuts against the second cavity wall, and a positioning part is provided on one side of the first abutment surface. One end of the elastic member is nested and fixed with the positioning part, and the other end of the elastic member abuts against the first cavity wall.

[0019] In the aforementioned engine braking device with return function, the positioning part is either a boss or a groove. When the positioning part is a boss, one end of the elastic member is sleeved on the boss and abuts against the first abutting surface; when the positioning part 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 aforementioned engine braking device with a return function, 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. Each of the two rocker arm supports is provided with a first connecting part. The return spring bracket is plate-shaped, and each end of the return spring bracket is provided with a first connecting hole. The two ends of the return spring bracket are connected to the two first connecting parts respectively by fasteners passing through the first connecting holes. The two sides of the opening end of the second cavity are respectively located on both sides of the braking rocker arm.

[0021] In the aforementioned engine braking device with a return function, the first connecting part includes a support bolt screwed onto 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, comprising:

[0023] A camshaft, including an auxiliary cam, and having a non-working surface and a working surface on the outer contour of the auxiliary cam, wherein the distance between the working surface and the center of the base circle of the auxiliary cam is greater than the distance between the non-working surface and the center of the base circle of the auxiliary cam;

[0024] The braking rocker arm and rocker arm shaft are fitted by a shaft hole, and a limiting part is provided on the braking rocker arm. The axial direction of the rocker arm shaft is parallel to the axial direction of the cam shaft, and a second connecting part is provided on the rocker arm shaft.

[0025] The movable unit includes a sliding part that slides onto one end of the brake rocker arm and a rolling part connected to the sliding part. The movement of the sliding part causes the rolling part to have a gap with the working surface on the outer contour of the auxiliary cam, or 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 two ends that mate with the camshaft and the rocker arm shaft bore, respectively.

[0027] The return spring bracket has one end connected to the second connecting part and the other end provided with a return spring seat, which is disposed opposite to the limiting part. The rocker arm is restricted to rotate in the direction close to the camshaft by the return spring seat.

[0028] The elastic element is arranged laterally and is sandwiched between the return spring seat and the limiting part. One end of the elastic element is connected to the return spring seat, and the other end of the elastic element abuts against the limiting part. The direction in which the elastic element is compressed or released is consistent with the swing direction of the brake rocker arm.

[0029] When the engine is running normally, there is a gap between the rolling part and the working surface of the auxiliary cam, and the elastic element is in a compressed and stored energy state.

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

[0031] In the aforementioned engine braking device with a return function, the limiting part includes a first cavity disposed on the brake rocker arm. The opening of the first cavity is away from the position of the rocker arm shaft, and the first cavity includes a first cavity wall and a second cavity wall. The return spring seat abuts against the second cavity wall, and the elastic element abuts against the first cavity wall. When the engine brakes and the rolling part contacts the non-working surface, the return spring seat abuts against the second cavity wall; when the engine brakes and the rolling part contacts the working surface, the return spring seat separates from the second cavity wall.

[0032] In the aforementioned engine braking device with a return function, a raised portion is provided on the return spring bracket, and a second recess is provided on the raised portion. The position of the second recess is opposite to that of the first recess, and the opening direction of the second recess is opposite to that of the first recess. The second recess and the first recess are joined together to form a closed cavity, and the elastic element is located in the closed cavity. There is a gap between the bottom of the second recess and the plane where the opening of the first recess is located.

[0033] In the aforementioned engine braking device with return function, the second cavity and the first cavity are integrated on the brake rocker arm, wherein the side of the limiting part is provided with a closed structure.

[0034] In the aforementioned engine braking device with a return function, 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. The return spring bracket is plate-shaped, and each end of the return spring bracket is provided with a first connecting hole. 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 cavity are respectively located on both sides of the braking rocker arm.

[0035] In the aforementioned engine braking device with a return function, the second connecting part includes a mounting plane and a second connecting hole is provided on the mounting plane, wherein a fastener is screwed into the second connecting hole via a return spring bracket.

[0036] In the aforementioned engine braking device with a return function, there are two second connection holes, and the two second connection holes are arranged side by side.

[0037] The present invention also provides an engine, characterized in that it includes the aforementioned engine braking device with a return function. Beneficial effects

[0038] Compared with the prior art, the present invention has the following beneficial effects:

[0039] (1) The present invention provides an engine braking device with a return function, which sets the elastic element laterally, thereby reducing the overall size of the engine braking device in the vertical direction, avoiding the situation that it cannot be installed or will collide with other parts in the engine after installation. In addition, by setting the limiting part, the relative clearance between the rolling part and the camshaft can be precisely controlled when the engine is working normally, reducing friction work and reducing the fuel consumption of the entire engine. Moreover, the setting of the limiting part can prevent the elastic element from twisting or bending when it is compressed or released, thereby improving the braking effect of the engine braking device.

[0040] (2) The limiting part is set as a concave cavity structure, and the elastic element is arranged laterally in the concave cavity structure. The two ends of the elastic element are clamped between the first cavity wall and the return spring seat, and indirectly clamped between the first cavity wall and the second cavity wall, thereby improving the straightness of the elastic element when it is compressed or released.

[0041] (3) By setting a positioning part on the return spring seat, the radial degree of freedom of the elastic element during the movement can be limited, and the elastic element can be prevented from sliding relative to the return spring seat when it is compressed or released. In addition, the positioning part can also be used as a connection and fixation between the elastic element and the return spring seat, so that the return spring bracket and the elastic element form a "whole" and improve the assembly efficiency of the engine braking device. Attached Figure Description

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

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

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

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

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

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

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

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

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

[0051] In the picture,

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

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

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

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

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

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

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

[0059] 80. Elastic components. Embodiments of the present invention

[0060] Detailed Implementation

[0061] The following are specific embodiments of the present invention, which are described in conjunction with the accompanying drawings. However, the present invention is not limited to these embodiments.

[0062] It should be noted that all directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of the present invention are only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indication will also change accordingly.

[0063] As shown in Figures 1 to 9, the present invention provides an engine braking device with a return function, comprising:

[0064] The camshaft 10 includes an auxiliary cam 11, and a non-working surface 111 and a working surface 112 are provided on the outer contour of the auxiliary cam 11, wherein the distance between the working surface 112 and the center of the base circle of the auxiliary cam 11 is greater than the distance between the non-working surface 111 and the center of the base circle of the auxiliary cam 11.

[0065] The braking rocker arm 20 and the rocker arm shaft 30 are fitted by a shaft hole, and a limiting part is provided on the braking rocker arm 20. The axial direction of the rocker arm shaft 30 is parallel to the axial direction of the cam shaft 10.

[0066] The movable unit 40 includes a sliding part 41 that slides onto one end of the brake rocker arm 20, and a rolling part 42 connected to the sliding part 41. The movement of the sliding part 41 causes the rolling part 42 to have a gap with the working surface 112 on the outer contour of the auxiliary cam 11, or to contact the outer contour of the auxiliary cam 11. The axial direction of the rolling part 42 is parallel to the axial direction of the camshaft 10.

[0067] The rocker arm support 50 has two ends that are respectively engaged with the shaft holes of the camshaft 10 and the rocker arm shaft 30, and a first connecting part 51 is provided on the rocker arm support 50;

[0068] The return spring bracket 60 is connected to the first connecting part 51 at one end and a return spring seat 70 is provided at the other end. The return spring seat 70 is disposed opposite to the limiting part. The rocker arm 20 is restricted to rotate in the direction close to the camshaft 10 by the return spring seat 70.

[0069] The elastic element 80 is arranged laterally and is sandwiched between the return spring seat 70 and the limiting part. One end of the elastic element 80 is connected to the return spring seat 70, and the other end of the elastic element 80 abuts against the limiting part. The direction in which the elastic element 80 is compressed or released is consistent with the swing direction of the brake rocker arm.

[0070] When the engine is working normally, there is a gap between the rolling part 42 and the working surface 112 of the auxiliary cam 11, and the elastic element 80 is in a compressed energy storage state.

[0071] When the engine brakes, the rolling part 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 part 42, the brake rocker arm 20 swings back and forth around the rocker arm shaft 30. When the rolling part 42 contacts the non-working surface 111, the distance between the return spring seat 70 and the limiting part is the smallest; when the rolling part 42 contacts the working surface 112, the distance between the return spring seat 70 and the limiting part is the largest.

[0072] In the prior art, the elastic element 80 connected to the return spring bracket 60 is arranged vertically. This structural arrangement makes the overall size of the entire engine braking device in the vertical direction large, which may cause the engine braking device to collide with the engine cover after assembly, or may make it impossible to install the engine braking device.

[0073] The present invention provides an engine braking device with a return function, which sets the elastic element 80 laterally, thereby reducing the overall size of the engine braking device in the vertical direction and avoiding situations where it cannot be installed or collides with other components in the engine after installation. In addition, by setting a limiting part, the relative clearance between the rolling part 42 and the camshaft 10 can be precisely controlled when the engine is working normally, reducing friction work and reducing the fuel consumption of the entire engine. Moreover, the setting of the limiting part can prevent the elastic element 80 from twisting or bending when it is compressed or released, thereby improving the braking effect of the engine braking device.

[0074] It is worth mentioning that, as described in the above embodiment, one end of the return spring bracket 60 is connected to the first connecting portion 51 of the rocker arm support 50 by a fastener. Similarly, one end of the return spring bracket 60 can be connected to the second connecting portion 31 of the rocker arm shaft 30 by a fastener. The reason why the return spring bracket 60 can be connected to either the rocker arm support 50 or the rocker arm shaft 30 is that when the engine is braking, the braking rocker arm 20 is in motion, while the return spring bracket 60 is in a stationary state. In the engine braking device, regardless of whether the engine is in normal operation or braking state, the rocker arm support 50 and the rocker arm shaft 30 are both in a stationary state. Therefore, the return spring bracket 60 can also be in a stationary state by connecting to either the rocker arm support 50 or the rocker arm shaft 30.

[0075] 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 element 80 is connected to the return spring seat 70. When the engine is in braking state, the elastic element 80 is constantly being compressed or released. During the compression or release process, the elastic element 80 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 connecting part 51 or the second connecting part 31), then the return spring bracket 60 will have a similar "cantilever beam" structure after being fixed. Moreover, the return spring bracket 60 is plate-shaped and is prone to "shaking" under the dynamic action of the elastic element 80, thereby affecting the braking effect of the engine braking device. Therefore, in order to prevent the return spring bracket 60 from "vibrating" during the compression or release of the elastic element 80, the return spring bracket 60 needs to be "reinforced". Thus, in this embodiment, when the return spring bracket 60 is connected to the rocker arm support 50, two rocker arm supports 50 are provided, and the two rocker arm supports 50 are positioned at both ends of the camshaft 10 along the axial direction of the camshaft 10. Each of the two rocker arm supports 50 has a first connecting part 51, and the line connecting the two first connecting parts 51 is parallel to the axial direction of the camshaft 10. Thus, both ends of the return spring bracket 60 are respectively connected to the two first connecting parts 51, and the return spring seat 70 is positioned between the two ends of the return spring bracket 60.

[0076] Similarly, when the return spring bracket 60 is connected to the rocker arm shaft 30, there are two second connecting parts 31, which are arranged at both ends of the rocker arm shaft 30 along the axial direction of the rocker arm shaft 30. The two ends of the return spring bracket 60 are respectively connected to the two second connecting parts 31, and the return spring seat 70 is arranged between the two ends of the return spring bracket 60.

[0077] In addition, it is worth mentioning that when each rocker arm support 50 is provided with a first connecting part 51, the types of rocker arm supports 50 can be reduced, making management easier; when each rocker arm shaft 30 is provided with a second connecting part 31 at both ends, the rocker arm shaft 30 can be designed to prevent mistakes, thus accelerating the assembly speed of the entire engine braking device.

[0078] Preferably, the first connecting part 51 includes a support bolt screwed onto the rocker arm support 50, and both ends of the return spring bracket 60 are provided with first connecting holes 61. The connection between the return spring bracket 60 and the rocker arm support 50 can be completed by passing a fastener through the first connecting hole 61 and screwing it into the support bolt, which makes disassembly and assembly relatively convenient.

[0079] Preferably, the second connecting part 31 includes a mounting plane 311 and a second connecting hole 312 is provided on the mounting plane 311. Both ends of the return spring bracket 60 are provided with first connecting holes 61. 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, making disassembly and assembly relatively convenient.

[0080] It is worth mentioning that when the return spring bracket 60 is connected to the rocker arm shaft 30, the second connecting hole 312 is not directly opened on the rocker arm shaft 30. Instead, the mounting surface 311 is first set on the rocker arm shaft 30, and then the second connecting hole 312 is set on the mounting surface 311. The advantage of this is that when the return spring bracket 60 is connected to the rocker arm shaft 30, the contact area between the return spring bracket 60 and the rocker arm shaft 30 is increased, thereby improving the reliability of the connection between the two. In addition, regarding the processing technology of the second connecting hole 312, compared with processing holes on a "curved surface", processing on a "flat surface" is more convenient and the hole diameter is more precise.

[0081] More preferably, each second connecting part 31 has two second connecting holes 312, and the two second connecting holes 312 are arranged side by side, so as to adapt to different sizes of return spring brackets 60 and improve the flexibility of the connection of return spring brackets 60.

[0082] In addition, by providing two second connecting holes 312, the return spring bracket 60 can also achieve a "misaligned connection" when connected to the second connecting 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 connecting hole 312 near one end of the rocker arm shaft 30, and the other end is connected to the second connecting hole 312 away from the other end of the rocker arm shaft 30. "Symmetrical connection" means that both ends of the return spring bracket 60 are simultaneously connected to the second connecting holes 312 near the corresponding ends of the rocker arm shaft 30, or simultaneously connected to the second connecting holes 312 away from the corresponding ends of the rocker arm shaft 30.

[0083] Preferably, the limiting part includes a first cavity 21 disposed on the brake rocker arm 20. The opening of the first cavity 21 is away from the position where the rocker arm shaft 30 is located. The first cavity 21 includes a first cavity wall 211 and a second cavity wall 212. 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 the engine brakes and the rolling part 42 contacts the non-working surface 111, the return spring seat 70 abuts against the second cavity wall 212. When the engine brakes and the rolling part 42 contacts the working surface 112, the return spring seat 70 separates from the second cavity wall 212.

[0084] It is worth mentioning that, as shown in the figure, when the engine is working normally, the elastic element 80 is in an energy-storing state, which can cause the brake rocker arm 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 arm 20 can be limited, so that when the movable unit 40 on the brake rocker arm 20 is not extended, there is a gap between the rolling part 42 connected to the movable unit 40 and the working surface 112 on the auxiliary cam 11, and the size of this gap can be strictly controlled. When the engine is braking, the movable unit 40 extends and the rolling part 42 contacts the outer contour of the auxiliary cam 11. As the rolling part 42 continuously passes through the working surface 112 and the non-working surface 111 on the auxiliary cam 11, the return spring seat 70 continuously contacts or separates from the second cavity wall 212, while the elastic element 80 is continuously compressed or released.

[0085] In this embodiment, the limiting part is configured as a concave cavity structure, and the elastic member 80 is laterally disposed in the concave cavity structure. The two ends of the elastic member 80 are clamped between the first cavity wall 211 and the return spring seat 70, and 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.

[0086] In addition, the two sides of the opening of the first concave cavity 21 can be treated at the same height, or there can be a height difference between the two, and there is no strict limitation on it.

[0087] It is worth mentioning that the limiting part is integrally set with the brake rocker arm 20.

[0088] Preferably, the return spring bracket 60 is provided with a raised portion, and the raised portion is provided with a second cavity 62. The position of the second cavity 62 is opposite to the position of the first cavity 21, and the opening direction of the second cavity 62 is opposite to the opening direction of the first cavity 21. The second cavity 62 and the first cavity 21 are spliced ​​together to form a closed cavity, and the elastic element 80 is located in the closed cavity. There is a gap between the bottom of the second cavity 62 and the plane where the opening of the first cavity 21 is located.

[0089] It is worth mentioning that the first cavity 21 on the braking rocker arm 20 is U-shaped, meaning that a first cavity wall 211 and a second cavity wall 212 are provided in the reciprocating swing direction of the braking rocker arm 20, while no corresponding cavity walls are provided on either side along the axial direction of the rocker arm shaft 30. Therefore, to prevent the elastic element 80 from "running out" of the first cavity 21 during compression or release, a second cavity 62 is provided on the return spring bracket 60, and the position of the second cavity 62 corresponds to the position of the first cavity 21. The opening direction of the second cavity 62 is opposite to the opening direction of the first cavity 21, forming a kind of "interlocking" relationship. The two cavity walls on the second cavity 62 are arranged along the axial direction of the rocker arm shaft 30. This makes the position where the elastic element 80 is located connected by the first cavity 21 and the second cavity 62 into a closed cavity, thereby avoiding the risk of the elastic element 80 "running out".

[0090] Alternatively, the two walls of the second cavity 62 can also be set on the brake rocker arm 20. In this way, the side of the first cavity 21 on the brake rocker arm 20 is a closed structure, and the second cavity 62 is not set on the return spring bracket 60. This arrangement can also achieve the "full enclosure" of the elastic element 80 and improve the reliability of the elastic element 80 during use.

[0091] Preferably, the return spring seat 70 is connected to the edge of the raised portion, and the two sides of the return spring seat 70 along the compression direction of the elastic member 80 are respectively the first abutment surface 71 and the second abutment surface 72. The second abutment surface 72 abuts against the second cavity wall 212. A positioning part 73 is provided on one side of the first abutment surface 71, and one end of the elastic member 80 is nested and fixed with the positioning part 73, while the other end of the elastic member 80 abuts against the first cavity wall 211.

[0092] In this embodiment, by providing a positioning part 73 on the return spring seat 70, the radial degree of freedom of the elastic member 80 during movement can be limited, preventing the elastic member 80 from sliding relative to the return spring seat 70 when compressed or released. In addition, the positioning part 73 can also serve as a connection and fixation between the elastic member 80 and the return spring seat 70, so that the return spring bracket 60 and the elastic member 80 form a "whole", improving the assembly efficiency of the engine braking device.

[0093] It is worth mentioning that the positioning part 73 is either a boss or a groove. When the positioning part 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 part 73 is a groove, one end of the elastic member 80 is embedded in the groove and abuts against the bottom of the groove.

[0094] In addition, the return spring bracket 60 is plate-shaped and has multiple bends to improve the overall strength of the return spring bracket 60. The return spring seat 70 is connected to the return spring bracket 60 by welding, or the return spring seat 70 is formed by bending the edge of the return spring bracket 60. Both of these methods are acceptable, but not limited to the two methods mentioned above.

[0095] It should be noted that in this invention, the use of terms such as "first," "second," and "a" is for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified. The terms "connection," "fixed," etc., should be interpreted broadly. For example, "fixed" can mean a fixed connection, a detachable connection, or an integral part; it can mean a mechanical connection or an electrical connection; it can mean a direct connection or an indirect connection through an intermediate medium; it can mean the internal communication of two elements or the interaction between two elements, unless otherwise explicitly specified. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0096] Furthermore, the technical solutions of the various embodiments of the present invention can be combined with each other, but only if they are feasible for those skilled in the art. If the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such combination of technical solutions does not exist and is not within the scope of protection claimed by the present invention.

[0097] The specific embodiments described herein are merely illustrative of the spirit of the invention. Those skilled in the art to which this invention pertains may make various modifications or additions to the described specific embodiments or use similar methods to substitute them, without departing from the spirit of the invention or exceeding the scope defined by the appended claims.

Claims

1. An engine braking device with a return function, characterized in that, include: A camshaft, including an auxiliary cam, and having a non-working surface and a working surface on the outer contour of the auxiliary cam, wherein the distance between the working surface and the center of the base circle of the auxiliary cam is greater than the distance between the non-working surface and the center of the base circle of the auxiliary cam; The braking rocker arm and rocker arm shaft are fitted by a shaft hole, and a limiting part is provided on the braking rocker arm. The axial direction of the rocker arm shaft is parallel to the axial direction of the cam shaft. The movable unit includes a sliding part that slides onto one end of the brake rocker arm and a rolling part connected to the sliding part. The movement of the sliding part causes the rolling part to have a gap with the working surface on the outer contour of the auxiliary cam, or 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. The rocker arm support has two ends that mate with the camshaft and the rocker arm shaft holes respectively, and a first connecting part is provided on the rocker arm support; The return spring bracket has one end connected to the first connecting part and the other end provided with a return spring seat, which is disposed opposite to the limiting part. The rocker arm is restricted to rotate in the direction close to the camshaft by the return spring seat. The elastic element is arranged laterally and is sandwiched between the return spring seat and the limiting part. One end of the elastic element is connected to the return spring seat, and the other end of the elastic element abuts against the limiting part. The direction in which the elastic element is compressed or released is consistent with the swing direction of the brake rocker arm. When the engine is running normally, there is a gap between the rolling part and the working surface of the auxiliary cam, and the elastic element is in a compressed and stored energy state. When the engine brakes, the rolling part contacts the outer contour of the auxiliary cam. As the working surface and non-working surface on the auxiliary cam alternately contact the rolling part, the brake rocker arm swings back and forth around the rocker arm axis. When the rolling part contacts the non-working surface, the distance between the return spring seat and the limit part is the smallest; when the rolling part contacts the working surface, the distance between the return spring seat and the limit part is the largest.

2. The engine braking device with return function according to claim 1, characterized in that, The limiting part includes a first cavity disposed on the brake rocker arm. The opening of the first cavity is away from the position where the rocker arm shaft is located. The first cavity includes a first cavity wall and a second cavity wall. The return spring seat abuts against the second cavity wall, and the elastic element abuts against the first cavity wall. When the engine brakes and the rolling part contacts the non-working surface, the return spring seat abuts against the second cavity wall. When the engine brakes and the rolling part contacts the working surface, the return spring seat separates from the second cavity wall.

3. The engine braking device with return function according to claim 2, characterized in that, The return spring bracket is provided with a raised part, and the raised part is provided with a second cavity. The position of the second cavity is opposite to that of the first cavity, and the opening direction of the second cavity is opposite to that of the first cavity. The second cavity and the first cavity are spliced ​​together to form a closed cavity, and the elastic element is located in the closed cavity. There is a gap between the bottom of the second cavity and the plane where the opening of the first cavity is located.

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

5. The engine braking device with return function according to claim 3, characterized in that, The return spring seat is connected to the edge of the raised part, and the two sides of the return spring seat along the compression direction of the elastic member are respectively the first abutting surface and the second abutting surface. The second abutting surface abuts against the second cavity wall. A positioning part is provided on one side of the first abutting surface, and one end of the elastic member is nested and fixed with the positioning part, while the other end of the elastic member abuts against the first cavity wall.

6. The engine braking device with return function according to claim 5, characterized in that, The positioning part can be a boss or a groove. When the positioning part is a boss, one end of the elastic member is sleeved on the boss and abuts against the first abutting surface. When the positioning part is a groove, one end of the elastic member is embedded in the groove and abuts against the bottom of the groove.

7. The engine braking device with return function according to claim 4, characterized in that, There are two rocker arm supports, which are located at both ends of the camshaft along the axial direction of the camshaft. Each rocker arm support has a first connecting part. The return spring bracket is plate-shaped and has a first connecting hole at each end. Fasteners are used to connect the two ends of the return spring bracket to the two first connecting parts respectively through the first connecting holes. The two sides of the opening end of the second cavity are located on both sides of the braking rocker arm.

8. The engine braking device with return function according to claim 1, characterized in that, The first connecting part includes a support bolt screwed onto the rocker arm support, and a 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.

9. An engine braking device with a return function, characterized in that, include: A camshaft, including an auxiliary cam, and having a non-working surface and a working surface on the outer contour of the auxiliary cam, wherein the distance between the working surface and the center of the base circle of the auxiliary cam is greater than the distance between the non-working surface and the center of the base circle of the auxiliary cam; The braking rocker arm and rocker arm shaft are fitted by a shaft hole, and a limiting part is provided on the braking rocker arm. The axial direction of the rocker arm shaft is parallel to the axial direction of the cam shaft, and a second connecting part is provided on the rocker arm shaft. The movable unit includes a sliding part that slides onto one end of the brake rocker arm and a rolling part connected to the sliding part. The movement of the sliding part causes the rolling part to have a gap with the working surface on the outer contour of the auxiliary cam, or 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. The rocker arm support has two ends that mate with the camshaft and the rocker arm shaft bore, respectively. The return spring bracket has one end connected to the second connecting part and the other end provided with a return spring seat, which is disposed opposite to the limiting part. The rocker arm is restricted to rotate in the direction close to the camshaft by the return spring seat. The elastic element is arranged laterally and is sandwiched between the return spring seat and the limiting part. One end of the elastic element is connected to the return spring seat, and the other end of the elastic element abuts against the limiting part. The direction in which the elastic element is compressed or released is consistent with the swing direction of the brake rocker arm. When the engine is running normally, there is a gap between the rolling part and the working surface of the auxiliary cam, and the elastic element is in a compressed and stored energy state. When the engine brakes, the rolling part contacts the outer contour of the auxiliary cam. As the working surface and non-working surface on the auxiliary cam alternately contact the rolling part, the brake rocker arm swings back and forth around the rocker arm axis. When the rolling part contacts the non-working surface, the distance between the return spring seat and the limit part is the smallest; when the rolling part contacts the working surface, the distance between the return spring seat and the limit part is the largest.

10. The engine braking device with return function according to claim 9, characterized in that, The limiting part includes a first cavity disposed on the brake rocker arm. The opening of the first cavity is away from the position where the rocker arm shaft is located. The first cavity includes a first cavity wall and a second cavity wall. The return spring seat abuts against the second cavity wall, and the elastic element abuts against the first cavity wall. When the engine brakes and the rolling part contacts the non-working surface, the return spring seat abuts against the second cavity wall. When the engine brakes and the rolling part contacts the working surface, the return spring seat separates from the second cavity wall.

11. The engine braking device with return function according to claim 10, characterized in that, The return spring bracket is provided with a raised part, and the raised part is provided with a second cavity. The position of the second cavity is opposite to that of the first cavity, and the opening direction of the second cavity is opposite to that of the first cavity. The second cavity and the first cavity are spliced ​​together to form a closed cavity, and the elastic element is located in the closed cavity. There is a gap between the bottom of the second cavity and the plane where the opening of the first cavity is located.

12. The engine braking device with return function according to claim 11, characterized in that, The second cavity is integrated with the first cavity on the brake rocker arm, wherein the side of the limiting part is a closed structure.

13. The engine braking device with return function according to claim 11, 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. The return spring bracket is plate-shaped and has a first connecting hole at each end. The two ends of the return spring bracket are connected to the two second connecting parts respectively by fasteners passing through the first connecting holes. The two sides of the opening end of the second cavity are located on both sides of the braking rocker arm.

14. The engine braking device with return function according to claim 9, characterized in that, The second connecting part includes a mounting plane and a second connecting hole is provided on the mounting plane, wherein a fastener is screwed into the second connecting hole via a return spring bracket.

15. The engine braking device with return function according to claim 14, characterized in that, There are two second connection holes, and the two second connection holes are arranged side by side.

16. An engine, characterized in that, include: The engine braking device with return function as described in claim 1 or 9.

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