Buffer mechanism of engine brake rocker arm

Abstract

The buffering mechanism of the engine braking rocker arm comprises an elastic body, the elastic body is arranged between the rocker arm and a rocker arm shaft, the elastic body abuts against the rocker arm and the rocker arm shaft, and elastic deformation of the elastic body exerts acting force between the rocker arm and the rocker arm shaft. When the rocker arm is driven to move, the motion resistance of the rocker arm on the rocker arm shaft is caused, the motion resistance keeps the rocker arm in two non-collision positions on the rocker arm shaft, and in the two non-collision positions, one end of the rocker arm avoids driving of an engine cam, and the other end of the rocker arm avoids acting with an engine valve. The rocker arm does not move in the ignition period of an engine, mechanism flying-off, friction and oil consumption are eliminated, and the use frequency is greatly reduced.

Description

TECHNICAL FIELD

[0001] The present embodiment relates to the field of machinery, and in particular to an engine, and more particularly to a buffer mechanism of an engine brake rocker arm. BACKGROUND

[0002] US Patent No. 5626116 (1997) discloses a dedicated brake rocker arm. The dedicated brake rocker arm houses a hydraulic brake actuation mechanism, including a hydraulic piston. When engine braking is not required, the hydraulic piston in the dedicated brake rocker arm is in a retracted position, the dedicated brake rocker arm is separated from the valve, the movement of the dedicated brake cam is skipped (lost), and no brake valve movement is generated; when engine braking is required, the hydraulic piston in the dedicated rocker arm is in an extended position, the dedicated rocker arm transmits the movement of the dedicated brake cam to one of the two exhaust valves, generating engine brake valve movement.

[0003] US Patent No. 5,975,251 (1999) discloses a locking device for a dedicated brake rocker arm. When not braking (firing), the dedicated brake rocker arm is locked on the rocker shaft, both ends are suspended, neither touching the brake cam nor hitting the brake valve. This locking device is used in the dedicated brake rocker arm of Cummins ISX engine, but it is found to be unreliable, the rocker arm will sway and impact on the rocker shaft, causing engine damage. Obviously, during braking, the rocker arm can rotate freely on the rocker shaft and cannot be positioned, and it is likely to collide with the cam or valve, resulting in poor reliability.

[0004] The existing dedicated brake rocker arm is biased on the cam by a spring and is driven by the cam. For example, the rocker arm in Chinese Utility Model Patent No. CN201666172U is biased on the brake cam by a spring installed between the bracket and the pressing plate, so a special spring bracket needs to be added to the engine, occupying a large space, and installation is not convenient, and the cost is high. Since the rocker arm is always driven by the brake cam (both during firing and braking), the rocker arm generates unnecessary movement during engine firing operation, greatly increasing the use frequency and wear and impact of the rocker arm. In addition, the spring must have a large pre-tightening force to maintain the engine brake rocker arm in contact with the cam (not fly off) during rotation of the cam shaft. SUMMARY

[0005] The engine brake rocker arm buffer mechanism of the present embodiment aims to solve the problems of poor reliability of the locking mechanism of the engine brake rocker arm, the need for a spring with large pre-tightening force and a special bracket, large space occupation, inconvenient installation, high cost, useless movement of the rocker arm during engine ignition operation, increased frequency of use, wear and tear and oil consumption in the prior art.

[0006] The engine brake rocker arm buffer mechanism of the present embodiment aims to solve the problems of poor reliability of the locking mechanism of the engine brake rocker arm, the need for a spring with large pre-tightening force and a special bracket, large space occupation, inconvenient installation, high cost, useless movement of the rocker arm during engine ignition operation, increased frequency of use, wear and tear and oil consumption in the prior art.

[0007] Optionally, the rocker arm is provided with a containing space, and the elastic body is arranged in the containing space and in abutment with the inner wall of the containing space and the rocker shaft.

[0008] Optionally, the containing space is a containing groove, the rocker arm comprises a rocker shaft mounting hole for mounting the rocker shaft, the containing groove is arranged in the rocker shaft mounting hole, and the elastic body is in abutment with the groove wall of the containing groove and the rocker shaft.

[0009] Optionally, the containing groove is a circumferential groove extending circumferentially along the rocker shaft mounting hole, the elastic body comprises an arc-shaped spring, the arc-shaped spring is arranged on one side of the rocker shaft and placed in the circumferential groove, and the arc-shaped spring comprises a bent protrusion arranged in the middle and two end portions.

[0010] The bent protrusion and the two end portions are in abutment with the groove wall of the circumferential groove and the rocker arm, respectively, or the bent protrusion and the two end portions are in abutment with the rocker arm and the groove wall of the circumferential groove, respectively.

[0011] Optionally, the elastic body comprises a leaf spring, and the leaf spring is arranged in a groove on the rocker arm.

[0012] Optionally, the containing groove is a circumferential groove extending circumferentially along the rocker shaft mounting hole, the elastic body comprises a C-shaped spring, the C-shaped spring is arranged on the outer side of the rocker shaft and placed in the circumferential groove in a surrounding manner, and the C-shaped spring comprises a bent protrusion arranged in the middle and two end portions.

[0013] The bent protrusion and the two ends are respectively in contact with the groove wall of the ring groove and the rocker arm, or the bent protrusion and the two ends are respectively in contact with the rocker arm and the groove wall of the ring groove.

[0014] Optionally, the C-type spring comprises a leaf spring or a steel wire spring.

[0015] Optionally, the accommodating space is an accommodating hole, the rocker arm comprises a rocker arm shaft mounting hole for mounting the rocker arm shaft, the accommodating hole intersects with the rocker arm shaft mounting hole, the hole wall of the accommodating hole and the hole wall of the rocker arm shaft mounting hole form a communicating connecting port, and the elastic body is arranged in the accommodating hole.

[0016] Part of the elastic body is in contact with the hole wall of the accommodating hole, and part of the elastic body is in contact with the rocker arm through the connecting port.

[0017] Optionally, the accommodating hole is arranged vertically to the rocker arm shaft mounting hole.

[0018] Optionally, the elastic body comprises an open elastic pin, an opening of the open elastic pin faces any one side of the two sides of the rocker arm, a cylindrical surface of the open elastic pin is in contact with the rocker arm shaft, an acting force between the rocker arm and the rocker arm shaft causes the open elastic pin to deform circumferentially, and the opening becomes smaller.

[0019] Optionally, the elastic body comprises a headed elastic pin, the headed elastic pin comprises an elastic pin body and an elastic pin head arranged at one end of the elastic pin body, a diameter of the elastic pin head is larger than a diameter of the elastic pin body, the elastic pin head is in contact with the hole wall of the accommodating hole, and the elastic pin body is in contact with the rocker arm shaft.

[0020] Optionally, the elastic body and the rocker arm are in contact and in contact, and / or the elastic body and the rocker arm shaft are in contact and in contact.

[0021] Compared with the prior art, the effect of the embodiment is positive and obvious. The rocker arm of the embodiment is positioned at a position not colliding with the brake cam and the engine valve, is not driven by the brake cam, has no movement in the non-braking (ignition) state of the engine, reduces wear and oil consumption, and enhances reliability and durability. In addition, the rocker arm buffering mechanism of the embodiment does not occupy space (especially does not increase height) and does not increase weight, has a compact structure, and is easy to install. BRIEF DESCRIPTION OF DRAWINGS

[0022] Figure 1 is a schematic view of the buffering mechanism of the engine brake rocker arm of embodiment 1, wherein the engine is in a braking (brake piston extended) state.

[0023] Figure 2 is a schematic view of the cushion mechanism of the engine brake rocker arm of Example 1, with the engine in the fire (brake piston retracted) condition.

[0024] Figure 3 is a schematic view of the elastomer of Example 1.

[0025] Figure 4 is a schematic view of the cushion mechanism of the engine brake rocker arm of Example 2, with the engine in the fire (brake piston retracted) condition rocker position.

[0026] Figure 5 is a schematic view of the cushion mechanism of the engine brake rocker arm of Example 3.

[0027] Figure 6 is a schematic view of the cushion mechanism of the engine brake rocker arm of Example 4. DETAILED DESCRIPTION

[0028] The above merely illustrates the embodiments of the present application by specific embodiments, and those skilled in the art can easily understand other advantages and effects of the present application from the content disclosed in the specification.

[0029] It should be understood that the structures, proportions, sizes, etc. shown in the drawings attached to the specification are merely used to understand and read by those skilled in the art in conjunction with the content disclosed in the specification, and do not define the limiting conditions for the implementation of the present application, so they do not have technical substantive significance. Any modification of the structure, change of the proportional relationship or adjustment of the size, without affecting the effects and purposes that can be produced by the present application, should still fall within the scope of the technical content disclosed by the present application. At the same time, the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer" and the like in the specification indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only used to facilitate the description of the embodiments of the present application and simplify the description, and therefore cannot be understood as indicating or implying that the devices or elements referred to must have a particular orientation, structure and operation. Therefore, it cannot be understood as a limitation on the embodiments of the present application. In addition, the terms "first", "second", "third" are only for descriptive purposes, and cannot be understood as indicating or implying relative importance.

[0030] In the description of the embodiments of the present application, it should be noted that unless specifically defined and limited otherwise, the terms "mount", "connected", "connection" should be understood broadly, for example, it can be fixed connection, or replaceable connection, or integral connection, it can be mechanical connection, or electrical connection, it can be direct connection, or indirect connection through intermediate medium, or internal connection of two elements. For those skilled in the art, the specific meaning of the above terms in the embodiments of the present application can be understood according to the specific circumstances.

[0031] Embodiment 1:

[0032] As shown in Figure 1 and Figure 2 , the engine brake rocker arm 210 (hereinafter referred to as rocker arm 210) is swingably arranged on the rocker shaft 205 (the engine exhaust rocker arm can be arranged side by side with the engine brake rocker arm 210 on the same rocker shaft, which is not shown here), one end of the rocker arm 210 (here, the roller 235, or the push rod mechanism) is provided with the cam (brake cam 230) of the engine, and the other end has the valve 301 (the valve rod of the valve 301 has a valve rod cap 405 on the upper surface, and the valve bridge 400 is pressed on the upper surface of the valve rod cap 405, and the exhaust rocker arm acts on the center of the valve bridge 400 to drive two exhaust valves) of the engine. The brake mechanism 100 is arranged in the rocker arm 210 above the valve 301.

[0033] When engine braking is required, the engine brake control mechanism (not shown) opens the oil supply, the brake mechanism 100 is opened, the brake piston 160 extends downward, and the rocker arm 210 is in the communication position as shown in Figure 1 . The valve 301 is connected through the valve rod cap 405 and the extended brake piston 160 (or directly connected through the valve bridge 400 and the extended brake piston 160); at the same time, the roller 235 is connected with the base circle 229 of the brake cam 230. The movement of the brake cam 230 on the brake cam 231 (there can also be EGR or BGR cam) is transmitted to the engine valve 301 through the rocker arm 210 and the brake piston 160 in the extended state in the rocker arm, and the required valve movement for engine braking is generated. Of course, the engine ignition valve movement (including exhaust valve movement) generated by the conventional valve driving mechanism (not shown) always exists and does not interfere with the brake valve movement (the opening phase and height of the ignition and brake valves are different).

[0034] In the conventional ignition (non-engine braking) operation, the engine brake control mechanism (not shown) is disconnected from the oil, the brake piston 160 is retracted, and the rocker arm 210 tends to (automatically positioned by the cam 230 and the valve 301 at both ends of the rocker arm 210) as shown in Figure 2The two non-impact positions shown, that is, one end of the rocker arm 210 is away from the driving of the cam 230 (the brake cam 231) and the other end is away from the action with the valve 301 (the valve cap 405), especially the gap 212 is formed between the rocker arm 210 and the base circle 229 of the brake cam 230 (the size of the gap 212 is not less than the lift of the brake cam, that is, not less than the height of the brake cam 231), so that the rocker arm 210 is not driven by the cam 230, the movement of the cam 230 is lost, and the valve movement of the engine brake is not generated. It is noted that the valve movement of the engine ignition (including the exhaust valve movement) is generated by the conventional valve driving mechanism (not shown) and is not affected by the engine brake.

[0035] In practical application, due to the bumping / vibration generated by the running of the vehicle, the rocker arm 210 in the engine ignition state in the two non-impact positions on the rocker arm shaft 205 may be disturbed, causing the rocker arm 210 to impact the cam 230 and / or the valve 301. In order to eliminate such disturbance, the buffer mechanism of the engine brake rocker arm of the embodiment is born. Figure 2

[0036] Referring to Figures 1 to 3 , the buffer mechanism 50 includes an elastic body 51, the elastic body 51 is located between the rocker arm 210 and the rocker arm shaft 205, the elastic body 51 is in abutment with the rocker arm 210 and the rocker arm shaft 205 respectively, the elastic body 51 can be in direct contact with the two, and the elastic deformation of the elastic body 51 applies a force between the rocker arm 210 and the rocker arm shaft 205, causing the movement resistance of the rocker arm 210 on the rocker arm shaft 205, keeping the rocker arm 210 in the "two non-impact" position on the rocker arm shaft 205. Figure 2 In this way, one end of the rocker arm 210 avoids the driving of the cam 230 (gap 212), and the other end of the rocker arm 210 avoids the action with the engine valve 301. Once the rocker arm 210 is not driven by the cam 230, there will be no flying off, and there is no need for a complex, large and expensive anti-flying mechanism. Abutment can be understood as forceful connection. The abutment can be direct contact and forceful connection (contact abutment), or non-direct contact and forceful connection, etc., and the contact can be fixed connection or non-fixed connection. Specifically, the elastic body and the rocker arm are in contact abutment, and / or the elastic body and the rocker arm shaft are in contact abutment. For example, the elastic body is in contact with A, A is in contact with the rocker arm, and the elastic body and the rocker arm are in non-contact abutment. For example, Figure 1 and Figure 2 The elastic body and the rocker arm are in contact abutment.

[0037] In an embodiment of the utility model, the rocker arm 210 is provided with a containing space, and the elastic body 51 is arranged in the containing space, and the elastic body 51 is in abutment with the inner wall of the containing space and the rocker arm shaft 205 respectively. ​

[0038] In an embodiment of the utility model, the accommodating space is an accommodating groove, the rocker arm 210 includes a rocker arm shaft mounting hole 2051 for mounting the rocker arm shaft, the accommodating groove is arranged in the rocker arm shaft mounting hole 2051, and the elastic body 51 abuts against the groove wall of the accommodating groove and the rocker arm shaft 205 respectively.

[0039] In an embodiment of the utility model, the accommodating groove is a circumferential groove 53 extending along the circumference of the rocker arm shaft mounting hole 2051, and the elastic body includes an arc-shaped spring 51, which is arranged on one side of the rocker arm shaft 205 and placed in the circumferential groove 53. The arc-shaped spring 51 includes a bent protruding part 511 arranged in the middle and two end parts 512, wherein the bent protruding part 511 and the two end parts 512 abut against the groove wall of the circumferential groove 53 and the rocker arm 210 respectively, or the bent protruding part 511 and the two end parts 512 abut against the rocker arm 210 and the groove wall of the circumferential groove 53 respectively. The bent protruding part 511 can abut against the bottom groove wall of the circumferential groove 53, and the two end parts 512 can abut against the rocker arm 210. It should be noted that the end part 512 refers to the region at both ends of the arc-shaped spring 51, which is not necessarily the most edge place, but can also be a certain distance from the most edge.

[0040] In an embodiment of the utility model, the arc-shaped spring 51 of the present embodiment can be a leaf spring ( Figure 3 ) arranged in the circumferential groove 53 on the rocker arm 210 ( Figure 1 and Figure 2 ), the width of the circumferential groove 53 is greater than the width of the arc-shaped spring 51, and the length of the circumferential groove 53 is greater than the length of the arc-shaped spring 51 after deformation. It should be noted that the buffer mechanism 50 increases the movement (rotation) resistance of the rocker arm 210 on the rocker arm shaft 205, which increases the friction work (beneficial to increase the engine braking power), but does not increase the fuel consumption of the engine, because the engine does not spray oil during engine braking, and the brake rocker arm 210 is stationary (no rotation, no friction work) during engine ignition.

[0041] Embodiment 2:

[0042] Figure 4 is a schematic view of the engine braking rocker arm buffer mechanism of embodiment 2 in the engine ignition (brake piston retraction) state. This embodiment only describes the differences from embodiment 1, and the commonalities are not described again.

[0043] The accommodating groove is a ring groove 54 extending along the circumference of the rocker shaft mounting hole 2051, and the ring groove 54 is a 360° ring groove. The elastic body includes a C-shaped spring 52, which is arranged around the outer side of the rocker shaft 205 and placed in the ring groove 54. The C-shaped spring 52 includes a bent protrusion 521 arranged in the middle and two end portions 522. The bent protrusion 521 and the two end portions 522 are respectively in abutment with the groove wall of the ring groove 54 and the rocker 205, or the bent protrusion 521 and the two end portions 522 are respectively in abutment with the rocker 205 and the groove wall of the ring groove 54.

[0044] The C-shaped spring 52 can include a leaf spring and a steel wire spring.

[0045] Embodiment 3:

[0046] This embodiment only illustrates the differences from Embodiment 1, and the commonalities will not be described again. Refer to Embodiment 1 for the commonalities. Figure 5 The accommodating space of this embodiment is an accommodating hole 74, the rocker 210 includes a rocker shaft mounting hole 2051 for mounting the rocker shaft, the accommodating hole 74 intersects with the rocker shaft mounting hole 2051, the hole wall of the accommodating hole 74 and the hole wall of the rocker shaft mounting hole 2051 form a connecting port 2052 in communication, and the elastic body is arranged in the accommodating hole 74. Part of the elastic body is in abutment with the hole wall of the accommodating hole 2051, and part of the elastic body is in abutment with the rocker 210 through the connecting port 202.

[0047] In an embodiment of the present application, the accommodating hole 74 is arranged perpendicularly to the rocker shaft mounting hole 2051.

[0048] In an embodiment of the present application, the elastic body includes an open elastic pin 72, the open elastic pin 72 includes an opening and a cylindrical surface, the cylindrical surface is provided with the opening, the opening of the open elastic pin 72 faces any one side of the two sides of the rocker 210, the cylindrical surface of the open elastic pin is in abutment with the rocker shaft, the force between the rocker and the rocker shaft causes the open elastic pin to be circumferentially deformed, and the opening becomes smaller.

[0049] It should be noted that the planes where the two sides of the rocker 210 are located are substantially perpendicular to the axial direction of the rocker shaft mounting hole 2051.

[0050] Embodiment 4:

[0051] Figure 6The engine brake rocker arm cushion mechanism of Example 4 is described below, with only the differences from Examples 1 and 3 being described, and the commonalities not being described. The cushion mechanism 80 includes a head-elastic pin 82, which includes a pin body 85 and a pin head 81 disposed at one end of the pin body 85, the pin head 81 having a larger diameter than the pin body 85, wherein the pin head 81 abuts the wall of the receiving hole 84, and the pin body 85 abuts the rocker shaft.

[0052] The head-elastic pin 82 is disposed in the receiving hole 84 in the rocker arm 210, the receiving hole 84 having the same diameter as the pin head 81 of the head-elastic pin 82. The receiving hole 84 is perpendicular to the rocker shaft 205, which can be understood as the receiving hole 84 being disposed perpendicular to the rocker shaft mounting hole 2051. It is noted that the head-elastic pin 82 is elastically (bendingly) deformed after the rocker arm 210 is mounted on the rocker shaft 205, thereby generating a force between the rocker arm 210 and the rocker shaft 205.

[0053] The above examples are intended to be illustrative only and are not intended to limit the present embodiments. Indeed, those skilled in the art can readily devise modifications and variations to the present embodiments without departing from the scope and spirit of the present embodiments. For example, a function described or illustrated in one specific mechanism can be used in another specific mechanism to obtain a new mechanism. The rocker arms in the examples can be other types of rocker arms besides engine brake rocker arms, such as EGR rocker arms or rocker arms for variable valve actuation of an engine. In addition, the engine brake mechanism in the rocker arms can be of different types, and besides the brake mechanism, other mechanisms such as EGR mechanisms can be used. Also, the location and mounting of the cushion mechanism can be different. In addition, the form and mounting of the elastic body can be different. Accordingly, the present embodiments are intended to embrace all such modifications and variations as long as they fall within the scope of the appended claims or the equivalents thereof.

Claims

1. A buffer mechanism for an engine brake rocker arm, characterized in that: The rocker arm is rotatably mounted on the rocker arm shaft of the engine. The buffer mechanism applies a force between the rocker arm and the rocker arm shaft to increase the movement resistance of the rocker arm on the rocker arm shaft and keep the rocker arm in a non-collision position on the rocker arm shaft. In the non-collision position, one end of the rocker arm avoids the drive of the engine cam and the other end of the rocker arm avoids the action of the engine valve. The buffer mechanism includes an elastic body disposed between the rocker arm and the rocker arm shaft. The elastic body abuts against the rocker arm and the rocker arm shaft respectively. The elastic deformation of the elastic body applies a force between the rocker arm and the rocker arm shaft.

2. The buffer mechanism of the engine brake rocker arm as described in claim 1, characterized in that: The rocker arm has a receiving space, and the elastic body is disposed in the receiving space. The elastic body abuts against the inner wall of the receiving space and the rocker arm shaft respectively.

3. The buffer mechanism of the engine brake rocker arm as described in claim 2, characterized in that: The accommodating space is an accommodating groove, the rocker arm includes a rocker arm shaft mounting hole for mounting the rocker arm shaft, the accommodating groove is disposed in the rocker arm shaft mounting hole, and the elastic body abuts against the groove wall of the accommodating groove and the rocker arm shaft respectively.

4. The buffer mechanism of the engine brake rocker arm as described in claim 3, characterized in that: The receiving groove is a circumferential groove extending circumferentially along the mounting hole of the rocker arm shaft. The elastic body includes an arc-shaped spring, which is disposed on one side of the rocker arm shaft and placed within the circumferential groove. The arc-shaped spring includes a curved protrusion in the middle and two ends. The curved protrusion abuts against the wall of the circumferential groove and the two ends abut against the rocker arm, or the curved protrusion abuts against the rocker arm and the two ends abut against the wall of the circumferential groove.

5. The buffer mechanism of the engine brake rocker arm as described in claim 1, characterized in that: The elastic body includes a leaf spring located in a slot on the rocker arm.

6. The buffer mechanism of the engine brake rocker arm as described in claim 3, characterized in that: The receiving groove is an annular groove extending circumferentially around the mounting hole of the rocker arm shaft. The elastic body includes a C-type spring, which is arranged in a ring around the outside of the rocker arm shaft and placed within the annular groove. The C-type spring includes a curved protrusion in the middle and two ends. The curved protrusion abuts against the wall of the annular groove and the two ends abut against the rocker arm, or the curved protrusion abuts against the rocker arm and the two ends abut against the wall of the annular groove.

7. The buffer mechanism of the engine brake rocker arm as described in claim 6, characterized in that: The C-type spring includes a leaf spring or a wire spring.

8. The buffer mechanism of the engine brake rocker arm as described in claim 2, characterized in that: The receiving space is a receiving hole, and the rocker arm includes a rocker arm shaft mounting hole for mounting the rocker arm shaft. The receiving hole intersects with the rocker arm shaft mounting hole, and the wall of the receiving hole and the wall of the rocker arm shaft mounting hole form a communicating connection. The elastic body is disposed within the receiving hole. A portion of the elastomer abuts against the wall of the receiving hole, and a portion of the elastomer abuts against the rocker arm through the connection port.

9. The buffer mechanism of the engine brake rocker arm as described in claim 8, characterized in that: The receiving hole is perpendicular to the rocker arm shaft mounting hole.

10. The buffer mechanism of the engine brake rocker arm as described in claim 8, characterized in that: The elastic body includes an open elastic pin, the opening of which faces either side of the rocker arm. The cylindrical surface of the open elastic pin abuts against the rocker arm shaft. The force between the rocker arm and the rocker arm shaft causes the open elastic pin to deform circumferentially, and the opening becomes smaller.

11. The buffer mechanism of the engine brake rocker arm as described in claim 8, characterized in that: The elastic body includes a headed elastic pin, which includes an elastic pin body and an elastic pin head disposed at one end of the elastic pin body. The diameter of the elastic pin head is larger than the diameter of the elastic pin body. The elastic pin head abuts against the wall of the receiving hole, and the elastic pin body abuts against the rocker arm shaft.

12. The buffer mechanism of the engine brake rocker arm as described in claim 8, characterized in that: The elastomer and the rocker arm are in contact, and / or the elastomer and the rocker arm shaft are in contact.

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