Auxiliary valve drive mechanism
Patent Information
- Application Number
- CN202380059751.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Priority Date
- 2022-09-07
- Filing Date
- 2023-09-06
- Publication Date
- 2025-04-04
AI Technical Summary
Traditional engine brakes have problems such as increased height, weight, high cost, deformation, large inertia and slow response of the braking system due to hydraulic drive.
A fixed-chain auxiliary valve drive mechanism is adopted, including a box body, a connecting rod, a starting piston and a driving piston. The engine oil pressure acts on the starting piston, and the connecting rod and driving piston move in a plane along the guide groove, reducing hydraulic control and cost. Improve reaction speed and avoid liquid deformation and leakage.
It achieves the reduction of engine height and weight, lowers costs, improves response speed, enhances mechanism reliability and durability, avoids valve lift being affected by oil temperature, oil pressure and air content, and designs smaller valve lift values.
Smart Images
Figure CN119768593A_ABST
Abstract
Description
Auxiliary valve drive mechanism Technical Field
[0001] The present invention relates to the field of machinery, in particular to an engine, and more particularly to an auxiliary valve driving mechanism of an engine. Background Art
[0002] Conventional valve actuation methods for vehicle engines are well known in the art and have been used for over a century. However, due to additional requirements for engine emissions and engine braking (which can also assist in shifting), an increasing number of engines require the addition of auxiliary valve motions, such as those for exhaust gas recirculation and engine braking, in addition to conventional valve motion. Engine brakes, in particular, have become essential for heavy-duty commercial vehicle engines.
[0003] Traditional engine brakes are box-type, hydraulically actuated mechanisms mounted on top of the engine. Installing these engine brakes requires a gasket between the cylinder and valve cover, adding additional height, weight, and cost to the engine. These issues arise from treating the engine brake system as an additional accessory rather than an integral or integrated component.
[0004] Another drawback of traditional hydraulically actuated engine brakes is the hydraulic system's compressibility, or deformation. This is related to the fluid's flexibility. High flexibility results in a significant reduction in brake valve lift. This reduction in valve lift leads to an increase in valve load, which in turn leads to even greater flexibility, creating a vicious cycle. Furthermore, the reduction in valve lift caused by hydraulic deformation increases with increasing engine speed, directly counter to the desired brake valve lift trend required for engine braking performance. To reduce hydraulic flexibility, a large-diameter hydraulic piston must be used, increasing its size and weight. Furthermore, the oil flow required to extend or retract the large-diameter piston increases the inertia and response of the braking system.
[0005] Summary of the Invention
[0006] The object of the present invention is to provide a fixed-chain auxiliary valve drive mechanism, which is intended to solve the technical problem in the prior art that the overhead mounting method of the engine brake system increases the height, weight and manufacturing cost of the engine, and at the same time solve the technical problems of brake system deformation, large inertia and slow response existing in the hydraulically driven engine brake.
[0007] The auxiliary valve driving mechanism of the present invention comprises a housing, a connecting rod, a starting piston and a driving piston. The housing is provided with a starting piston hole and a driving piston hole which intersect vertically. The starting piston hole is provided with a starting piston. A driving piston is provided in the driving piston hole, and the connecting rod includes a connecting rod 1 and a connecting rod 2. The end face of the first end of the connecting rod 1 is connected to the box body through a rotating pair, and the end face of the second end of the connecting rod 1 and the end face of the first end of the connecting rod 2 are connected through a rotating pair. A rotating pair is provided between the end face of the second end of the connecting rod 2 and the end face 1 of the driving piston, and the end face 2 of the driving piston is located above the valve of the engine. It is characterized in that: a guide groove is provided at one end of the starting piston, the second end of the connecting rod 1 and the first end of the connecting rod 2 are located in the guide groove, and the connecting rod 1 and the connecting rod 2 make planar motion along the guide groove between the "closed" position and the "open" position. In the "closed" position, the connecting rod 1 and the connecting rod 2 form an angle, and the end face 2 of the driving piston leaves the engine valve; in the "open" position, the connecting rod 1 and the connecting rod 2 are located on the same axis, and the end face 2 of the driving piston is close to the engine valve.
[0008] Furthermore, a fluid channel is provided in the housing, which connects the starting piston hole with the engine oil fluid network. The pressure of the oil acts on the non-guide groove end of the starting piston in the starting piston hole, and the starting piston pushes connecting rod 1 and connecting rod 2 from the "closed" position to the "open" position along the guide groove in the housing.
[0009] Furthermore, a portion of the end surface of the starting piston is recessed inwardly along the axial direction of the starting piston to form a guide groove, and the guide groove penetrates the starting piston along the radial direction of the starting piston.
[0010] Furthermore, the bottom of the guide groove is provided with an arcuate surface matching the second end of the connecting rod one and the first end of the connecting rod two, and limiting surfaces are provided on both sides of the arcuate surface. The arcuate surface abuts against the connecting rod one and / or the connecting rod two and pushes the connecting rod one and the connecting rod two from the "closed" position to the "open" position between the two limiting surfaces.
[0011] Furthermore, the auxiliary valve driving mechanism also includes a connecting rod positioning mechanism, and the connecting rod positioning mechanism enables the connecting rod 1 and the connecting rod 2 to be located on the same axis when in the "open" position.
[0012] Furthermore, the connecting rod positioning mechanism includes a hollow cylinder, and one end surface of the hollow cylinder contacts the connecting rod 1 and the connecting rod 2 in the "open" position.
[0013] Furthermore, the auxiliary valve driving mechanism also includes a return mechanism, which pushes the connecting rod 1 and the connecting rod 2 from the "open" position to the "closed" position along the guide groove in the box body.
[0014] Furthermore, the return mechanism includes a return spring and a return piston, and the return spring acts on the connecting rod through the return piston.
[0015] Furthermore, the auxiliary valve drive mechanism also includes a drive piston spring, which acts on the drive piston so that the rotational pair between the end face 1 of the drive piston and the end face of the second end of the connecting rod 2 always remains connected.
[0016] Furthermore, the three revolving pairs are all spherical revolving pairs.
[0017] Furthermore, a valve clearance adjusting screw is provided on the box body, and the bottom surface of the valve clearance adjusting screw cooperates with the end surface of the first end of the connecting rod to form a rotating pair.
[0018] Furthermore, the box is a rocker arm of the engine.
[0019] Furthermore, the box is a valve bridge of the engine.
[0020] Compared with the existing technology, the effects of the present invention are positive and obvious. The present invention can be integrated with the engine, thereby reducing the height, volume and weight of the engine; there is no need to use a hydraulic control valve, which reduces costs and shortens reaction time; there is no liquid bearing, and there is no leakage, deformation and load fluctuation caused by high oil pressure and high oil temperature. The valve lift is not affected by oil temperature, oil pressure and air content, and the designed valve lift can obtain a smaller value, reducing the gap between the engine piston and the air valve. In addition, the ball head of the connecting rod and the inner piston are in line contact, which is better than the traditional point contact and improves the reliability and durability of the mechanism. In the present invention, a guide groove is provided at one end of the starting piston, which not only allows connecting rod one and connecting rod two to move along the guide groove in a plane between the "closed" position and the "open" position, but also extends the service life of connecting rod one and / or connecting rod two. BRIEF DESCRIPTION OF THE DRAWINGS
[0021] FIG1 is a schematic diagram of a housing of an auxiliary valve driving mechanism embodiment of the present invention.
[0022] FIG2 is a schematic diagram of an auxiliary valve driving mechanism embodiment of the present invention in a “closed” position.
[0023] FIG3 is a schematic diagram of an auxiliary valve driving mechanism embodiment of the present invention in an “open” position.
[0024] FIG4 is a cross-sectional view of a starting piston of an auxiliary valve driving mechanism embodiment of the present invention. DETAILED DESCRIPTION
[0025] The preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings so that the objects, features and advantages of the present invention can be more clearly understood. It should be understood that the embodiments shown in the accompanying drawings are not intended to limit the scope of the present invention, but are only intended to illustrate the essential spirit of the technical solutions of the present invention.
[0026] In the following description, for the purpose of illustrating the various disclosed embodiments, certain specific details are set forth in order to provide a thorough understanding of the various disclosed embodiments. However, those skilled in the relevant art will recognize that the embodiments may be practiced without one or more of these specific details. In other cases, well-known devices, structures, and techniques associated with this application may not be shown or described in detail to avoid unnecessarily obscuring the description of the embodiments.
[0027] References throughout this specification to "one embodiment" or "an embodiment" indicate that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment. Thus, the appearances of "in one embodiment" or "in an embodiment" in various places throughout this specification are not necessarily all referring to the same embodiment. Furthermore, the particular features, structures, or characteristics may be combined in any manner in one or more embodiments.
[0028] In the following description, in order to clearly show the structure and working mode of the present invention, many directional words will be used for description, but words such as "front", "back", "left", "right", "outside", "inside", "outward", "inward", "up", and "down" should be understood as convenient terms and should not be understood as restrictive terms.
[0029] As shown in Figures 1, 2, and 3, an auxiliary valve actuation mechanism 100 of the present invention includes a housing 210 (the housing shown in Figure 1 is part of an engine rocker arm, which is assembled to the engine rocker arm shaft (not shown) through a hole 212), connecting rods (Figures 2 and 3 include connecting rod 184 and connecting rod 2 186), a starting piston 162, and a driving piston 130. A starting piston hole 260 and a driving piston hole 190 are defined in the housing 210, intersecting each other. The starting piston 162 is positioned in the starting piston hole 260, and the driving piston 130 is positioned in the driving piston hole 190. The end face of the first end of connecting rod 184 is connected to the box body 210 (shown here is the adjusting screw 110 fixed on the box body 210) through a rotating pair 122, the end face of the second end of connecting rod 184 and the end face of the first end of connecting rod 2 186 are connected through a rotating pair 125, and a rotating pair 128 is provided between the end face of the second end of connecting rod 2 186 and the end face 1 (top) of the driving piston 130, and the end face 2 (bottom) 131 of the driving piston 130 is located above the engine valve (not shown).
[0030] The three revolute pairs 122, 125, and 128 illustrated in this embodiment are all spherical revolute pairs (a ball head and a ball socket). The revolute pair 125 is used for illustration. The implementation of the revolute pairs 122 and 128 can refer to the revolute pair 125. Referring to FIG2 , the ball head of the revolute pair 125 is disposed on the first connecting rod 184, and the ball socket of the second revolute pair 125 is disposed on the second connecting rod 186. In other implementations, the ball socket of the revolute pair 125 can also be disposed on the first connecting rod 184, and the ball head of the revolute pair 125 can also be disposed on the second connecting rod 186. In other implementations, the revolute pair 125 can also include two ball sockets and a ball head disposed between the two ball sockets, wherein the two ball sockets are disposed on the first connecting rod 184 and the second connecting rod 186, respectively.
[0031] One end 134 of the priming piston 162 is provided with a guide groove 137 (see Figures 2, 3, and 4). The width of guide groove 137 is equal to or slightly larger than the diameters of connecting rods 184 and 186 (connecting rods 1 and 2 have the same diameter). The second end of connecting rod 184 and the first end of connecting rod 2 186 are located within the guide groove. They move in a plane (a first plane) along guide groove 137 between the "closed" position (Figure 2) and the "open" position (Figure 3). In the "closed" position, the return spring 156 of the return mechanism, via the return piston (or push rod) 188, pushes connecting rods 184 and 186 along guide groove 137 toward the "closed" tilted position (Figure 2, where connecting rods 184 and 186 form an angle). The priming piston 162 rests against the bottom surface 246 (Figure 1) of the priming piston hole 260. At the same time, the driving piston spring 177 causes the driving piston 130 to move upward, and its bottom surface (end surface 2) 131 is separated from the engine valve (not shown).
[0032] It should be noted that:
[0033] First, FIG4 is a cross-sectional view of a starting piston of an auxiliary valve driving mechanism embodiment of the present invention, wherein the plane of the cross section is perpendicular to the first plane.
[0034] Second, referring to FIG. 4 , the width of the guide groove 137 refers to the distance between the upper and lower parts of the guide groove 137 .
[0035] In the prior art, the guide groove is not located on the starting piston, resulting in direct contact between connecting rod 1 and / or connecting rod 2 and the end surface of the starting piston. This means that when the starting piston and connecting rod 1 and / or connecting rod 2 engage with force, connecting rod 1 and / or connecting rod 2 and the starting piston form point contact. Furthermore, the force between connecting rod 1 and / or connecting rod 2 and the starting piston is relatively large, making connecting rod 1 and / or connecting rod 2 susceptible to damage during use. For example, referring to FIG2 , assuming starting piston 162 lacks guide groove 137, when starting piston 162 and connecting rod 1 and connecting rod 2 engage with force, the ball head of connecting rod 1 184 forms point contact with the end surface of starting piston 162, making connecting rod 1 184 susceptible to damage.
[0036] Through the design of the present invention, a guide groove is provided at the starting piston, which not only allows connecting rod one and connecting rod two to move along the guide groove in a plane between the "closed" position and the "open" position, but also can extend the service life of connecting rod one and / or connecting rod two.
[0037] In one embodiment of the present invention, referring to Figures 2, 3 and 4, a portion of the end surface of the starting piston 162 is recessed inward along the axial direction of the starting piston 162 to form a guide groove 137, and the guide groove 137 passes through the starting piston 162 along the radial direction of the starting piston 162.
[0038] With this design, the opening of the guide groove is located at the end face of the starting piston, which is easy to process, and allows the connecting rod 1 and the connecting rod 2 to move in a plane along the guide groove between the "closed" position and the "open" position.
[0039] In one embodiment of the present invention, referring to Figures 2, 3 and 4, the bottom of the guide groove 137 is provided with an arcuate surface 1371 that matches the second end of the connecting rod 184 and the first end of the connecting rod 2 186, and limiting surfaces 1372 are provided on both sides of the arcuate surface 1371. The arcuate surface 1371 abuts against the connecting rod 1 184 and / or the connecting rod 2 186 and pushes the connecting rod 1 184 and the connecting rod 2 186 from the "closed" position to the "open" position between the two limiting surfaces 1372.
[0040] Through such a design, when the starting piston has a strong effect on connecting rod one and / or connecting rod two, connecting rod one and / or connecting rod two are in line contact with the starting piston. It can be understood that connecting rod one and / or connecting rod two are in line contact with the arc surface. Compared with the point contact in the prior art, the service life of connecting rod one and / or connecting rod two can be extended.
[0041] It should be noted that, referring to Figures 2, 3 and 4:
[0042] First, in this embodiment, connecting rod 184 and connecting rod 2 186 have the same or substantially the same diameter. The second end of connecting rod 184 includes a ball head, and the first end of connecting rod 2 186 includes a socket. Arc surface 1371 matches the ball head and socket. When arc surface 1371 pushes connecting rod 184 and connecting rod 2 186 from the "closed" position to the "open" position, there is a force acting between arc surface 1371 and the ball head in the initial stage. In other words, there is a force acting between arc surface 1371 and connecting rod 1 184. When the "open" position is approaching, arc surface 1371 may act on both connecting rod 1 184 and connecting rod 2 186. In other embodiments, the ball head may be located at the second end of connecting rod 2 186. The force relationship can be referred to above and will not be repeated here. In other embodiments, those skilled in the art may know that when there is a simple modification to the mechanical connection method, the force relationship between the arc surface 1371 and the connecting rod 1 184 and the connecting rod 2 186 is slightly different, but the function of the arc surface 1371 remains unchanged, that is, when the pressure of the engine oil acts on the non-guide groove end of the starting piston 162 in the starting piston hole 260, the arc surface 1371 of the guide groove 137 in the starting piston 162 and the connecting rod 1 184 and / or the connecting rod 2 186 have a force effect, and push the connecting rod 1 184 and the connecting rod 2 186 from the "closed" position to the "open" position along the guide groove 137 in the box body.
[0043] Second, the distance between the two limiting surfaces 1372 is equal to the width of the guide groove 137 mentioned above.
[0044] When the auxiliary valve actuator 100 needs to be started, the engine's oil fluid network (not shown) supplies oil to the starting piston hole 260 through the fluid channel 214 provided in the housing (rocker arm) 210 (see FIG1 ). The oil pressure acts on the non-guide groove end 139 of the starting piston 162, overcoming the forces of the return spring 156 and the drive piston spring 177, and pushing the connecting rod 184 and the connecting rod 2 182 along the guide groove 137 from the "closed" inclined position to the "open" position (see the "upright" position in FIG3 ). In the "open" position, the connecting rod 184 and the connecting rod 2 186 are located on the same axis, the drive piston 130 moves downward, and its bottom surface (end surface 2) 131 approaches the engine valve (not shown).
[0045] The auxiliary valve actuation mechanism 100 of the present invention also includes a connecting rod positioning mechanism that ensures that connecting rod 184 and connecting rod 2 186 are coaxial when in the "open" position (see Figure 3). The connecting rod positioning mechanism includes a hollow cylinder 164 (illustrated here as a screw plug), one end surface 146 of which contacts connecting rod 184 and connecting rod 2 186 in the "open" position. The hollow cylinder 164 contains a return mechanism, whose inner bore 144 serves as a guide for a return piston 188.
[0046] Adjustment screw 110, mounted on housing 210, is used to adjust the initial vertical position (valve clearance) of drive piston 130 within drive piston bore 190. If adjustment of the initial position of drive piston 130 is not necessary, adjustment screw 110 is not required. In this case, the end surface of the first end of connecting rod 184 directly forms a revolute joint 122 with housing (rocker arm) 210.
[0047] The working process of this embodiment is as follows: when the auxiliary valve drive mechanism 100 needs to work, the engine valve drive control mechanism (not shown) starts the oil supply, and the engine oil is supplied to the starting piston hole 260 (see Figure 1) through the engine oil fluid network (not shown) of the engine via the fluid channel 214 in the housing (rocker arm) 210. The pressure of the engine oil acts on the starting piston 162 (the end surface 139 is subjected to the oil pressure), overcoming the force of the driving piston spring 177 and the return spring 156, and pushing the connecting rod 184 and the connecting rod 2 182 along the guide groove 137 from the "closed" position (the inclined, angled position in Figure 2) to the "open" position (the coaxial, upright position in Figure 3). The driving piston 130 connected to the bottom of the connecting rod 2 186 changes from the retracted position to the extended position, and its bottom surface (end surface 2) 131 is close to (connected to) the engine valve below, and the valve drive mechanism 100 switches from the non-operating position to the operating position. At this time, the movement of the engine cam (not shown) is transmitted to the engine valve through the rocker arm 210 and the valve drive mechanism 100 in the operating position in the rocker arm, generating the required auxiliary valve movement, such as the valve movement for engine braking.
[0048] When the auxiliary valve drive mechanism 100 is no longer required to operate, the engine brake control mechanism closes and unloads oil. The starting piston 162 is no longer subject to oil pressure and, under the action of the return spring 156 and the drive piston spring 177, returns to its original position, resting on the bottom surface 246 of the starting piston hole 260. Connecting rod 184 and connecting rod 2 186 return from their upright position to an inclined position. Drive piston 130, under the action of drive piston spring 177, retracts upward within vertical hole 190, separating its bottom surface (end surface 2) 131 from the underlying engine valve, creating a certain gap. This causes the movement of the engine cam (not shown) to be skipped and unable to be transmitted to the engine valve, resulting in no auxiliary valve movement.
[0049] The embodiments of the present invention are intended to illustrate the present invention rather than to limit it. In fact, those familiar with the art can easily modify and change the present invention within the scope and principle of the present invention. For example, a certain part of the function illustrated or described in a specific mechanism can be used in another specific mechanism, thereby obtaining a new mechanism. The housing in the embodiment can be not only a rocker arm, but also a valve bridge or even a fixed housing. In addition, the revolving pairs formed between connecting rod 1 and the housing (adjusting screw), between connecting rod 1 and connecting rod 2, and between connecting rod 2 and the drive piston can be cylindrical or other links in addition to being spherical. There are also different ways to guide and position the connecting rod. In addition to generating valve movement for engine braking, the auxiliary valve drive mechanism of the present invention can also generate other types of variable valve movement. Therefore, the present invention will include the above-mentioned modifications and changes as long as they fall within the scope of the attached claims or equivalent to the claimed rights.
[0050] While the preferred embodiments of the present invention have been described in detail above, it should be understood that, after reading the above teachings of the present invention, those skilled in the art may make various changes or modifications to the present invention. Such equivalents also fall within the scope of the claims appended hereto.
Claims
1. An auxiliary valve drive mechanism, comprising a housing, a connecting rod, a starting piston and a driving piston, wherein the housing is provided with a starting piston hole and a driving piston hole intersecting perpendicularly, the starting piston hole is provided with the starting piston, the driving piston hole is provided with the driving piston, the connecting rod comprises a first connecting rod and a second connecting rod, a first end face of the first connecting rod is connected to the housing via a revolute pair, a second end face of the first connecting rod is connected to the first end face of the second connecting rod via a revolute pair, a revolute pair is provided between the second end face of the second connecting rod and the end face 1 of the driving piston, and the end face 2 of the driving piston is located above the engine valve, characterized in that: A guide groove is provided at one end of the starting piston, and the second end of the connecting rod one and the first end of the connecting rod two are located in the guide groove. The connecting rod one and the connecting rod two make planar motion along the guide groove between the "closed" position and the "open" position. In the "closed" position, the connecting rod one and the connecting rod two form an angle, and the end face two of the driving piston leaves the engine valve; in the "open" position, the connecting rod one and the connecting rod two are located on the same axis, and the end face two of the driving piston is close to the engine valve.
2. The auxiliary valve drive mechanism according to claim 1, wherein: A fluid channel is provided in the housing, and the fluid channel connects the starting piston hole with the engine oil fluid network. The pressure of the engine oil acts on the end of the starting piston in the starting piston hole that is not the guide groove, and the starting piston pushes the connecting rod 1 and the connecting rod 2 in the housing along the guide groove from the "closed" position to the "open" position.
3. The auxiliary valve drive mechanism according to claim 1, wherein: A portion of the end surface of the starting piston is recessed inwardly along the axial direction of the starting piston to form a guide groove, and the guide groove penetrates the starting piston along the radial direction of the starting piston.
4. The auxiliary valve drive mechanism according to claim 1, wherein: The bottom of the guide groove is provided with an arcuate surface matching the second end of the connecting rod one and the first end of the connecting rod two, and limiting surfaces are provided on both sides of the arcuate surface. The arcuate surface abuts against the connecting rod one and / or the connecting rod two and pushes the connecting rod one and the connecting rod two from the "closed" position to the "open" position between the two limiting surfaces.
5. The auxiliary valve drive mechanism according to claim 1, wherein: The auxiliary valve driving mechanism further includes a connecting rod positioning mechanism, wherein the connecting rod positioning mechanism enables the connecting rod 1 and the connecting rod 2 to be located on the same axis when in the “open” position.
6. The auxiliary valve driving mechanism according to claim 5, wherein: The connecting rod positioning mechanism includes a hollow cylinder, one end surface of which contacts the connecting rod 1 and the connecting rod 2 in the "open" position.
7. The auxiliary valve driving mechanism according to claim 1, wherein: The auxiliary valve driving mechanism further includes a return mechanism, which pushes the connecting rod 1 and the connecting rod 2 from the "open" position to the "closed" position along the guide groove in the box body.
8. The auxiliary valve driving mechanism according to claim 7, wherein: The return mechanism includes a return spring and a return piston, and the return spring acts on the connecting rod through the return piston.
9. The auxiliary valve driving mechanism according to claim 1, wherein: The auxiliary valve driving mechanism further includes a driving piston spring, which acts on the driving piston so that the rotational pair between the first end face of the driving piston and the second end face of the connecting rod 2 is always kept connected.
10. The auxiliary valve driving mechanism according to claim 1, wherein: The three revolving pairs are all spherical revolving pairs.
11. The auxiliary valve driving mechanism according to claim 1, wherein: The box body is provided with a valve clearance adjusting screw, and the bottom surface of the valve clearance adjusting screw and the first end surface of the connecting rod 1 cooperate to form a rotating pair.
12. The auxiliary valve driving mechanism according to claim 1, wherein: The box body is the rocker arm of the engine.
13. The auxiliary valve driving mechanism according to claim 1, wherein: The box body is the valve bridge of the engine.