CN223089378U - Hydraulic tappet assembly mechanism - Google Patents
Hydraulic tappet assembly mechanism Download PDFInfo
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- CN223089378U CN223089378U CN202422287562.0U CN202422287562U CN223089378U CN 223089378 U CN223089378 U CN 223089378U CN 202422287562 U CN202422287562 U CN 202422287562U CN 223089378 U CN223089378 U CN 223089378U
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Abstract
The utility model discloses a hydraulic tappet assembly mechanism which comprises a tappet connecting part arranged at one end of a rocker arm, wherein the tappet connecting part is provided with a first oil way communicated with an engine oil way of an engine, a bowl seat is arranged at the end part of the tappet connecting part facing the hydraulic tappet, the hydraulic tappet is arranged on a valve bridge, the bottom of the bowl seat is abutted against the hydraulic tappet, a limiting hole communicated with the first oil way and an oil inlet of the hydraulic tappet is arranged at the bottom of the bowl seat, when an engine is braked in a cylinder, an oil drainage gap is formed between the bowl seat and the hydraulic tappet, at the moment, the end surface of the hydraulic tappet facing the bowl seat is an inclined surface, hydraulic oil flowing out of the limiting hole flows away along the inclined surface and cannot flow into an oil inlet of the hydraulic tappet, the hydraulic tappet is not stretched any more due to continuous supply of hydraulic oil, when the braking is finished, the valve is closed, the hydraulic tappet is immediately restored to a normal working state, and the assembly mechanism can be matched with a braking system in the cylinder of the engine well, so that the engine can keep a high-performance working state.
Description
Technical Field
The utility model relates to the technical field of engines, in particular to a hydraulic tappet assembly mechanism.
Background
In the valve train of the engine, the hydraulic tappet can be arranged on any transmission part between the cam and the valve, is used for transmitting the thrust of the cam shaft to the push rod (or the valve rod) and bearing the lateral force applied when the cam shaft rotates, and can automatically compensate the valve clearance, cancel the related parts for adjusting the valve clearance and eliminate noise and impact caused by the valve clearance relative to the mechanical tappet.
Among the in-cylinder braking technologies of the engine, the compression release type braking technology is the technology with the best engine braking performance at present, and the basic principle is that when the engine is towed backward, the piston compresses in-cylinder gas in the process of the ascending of the compression stroke piston, and braking power is generated. Before compression top dead center, the compression release type braking device drives the exhaust valve to open a certain opening degree, the compressed high-temperature high-pressure charge in the cylinder is discharged, at the moment, the pressure in the cylinder is rapidly reduced, after a certain crank angle is passed, the exhaust valve is closed again, the piston moves downwards, the work of the charge in the cylinder on the piston is greatly reduced because the charge in the cylinder is greatly reduced, and the reverse braking power of the charge in the cylinder on the piston is reduced or eliminated.
When the in-cylinder brake system is applied to a dual-valve train, a rocker arm drives two valves (two intake valves or two exhaust valves) simultaneously through a valve bridge, but when an engine is braked in a cylinder, the in-cylinder brake mechanism alone drives one valve to open, and if a conventional hydraulic tappet is arranged on the valve train, for example, the hydraulic tappet disclosed in patent application CN111472859a, the following problems may occur:
when the in-cylinder braking state is achieved, one valve is driven to be opened by the in-cylinder braking mechanism, the valve bridge moves downwards, the rocker arm does not move relatively, the hydraulic tappet stretches at the moment and automatically compensates a gap formed by the descending of the valve bridge, when the in-cylinder braking is finished, the valve is closed, and at the moment, the valve cannot be completely closed due to the fact that the hydraulic tappet is not shortened, so that the valve cannot be sealed in the subsequent working process, compressed gas in the cylinder leaks, and the in-cylinder braking effect is reduced or even fails.
Patent application CN111535893a discloses a braking system in the cylinder of an engine and a hydraulic tappet matched with the braking system, and proposes a solution, in the braking process in the cylinder, the hydraulic oil communication oil way of the hydraulic tappet is cut off, and the compression spring in the hydraulic tappet is replaced by an extension spring, so that the hydraulic tappet is not elongated any more, the problem of air leakage caused by valve elongation is solved, but in the braking process in the cylinder, under the combined action of valve spring force and camshaft thrust, the hydraulic tappet is continuously shortened when the valve is opened, gaps are generated between the hydraulic tappet and the valve (or other parts such as a valve bridge), and the valve is closed in the exhaust stroke, so that the service life of a moving part is influenced.
Disclosure of utility model
The utility model aims to provide a hydraulic tappet assembly mechanism.
In order to solve the technical problems, the hydraulic tappet assembly mechanism comprises a tappet connecting portion arranged at one end of a rocker arm and a valve bridge, wherein the tappet connecting portion is provided with a first oil way communicated with an engine oil way of an engine, a bowl seat is arranged at the end portion, facing the hydraulic tappet, of the tappet connecting portion, the hydraulic tappet is arranged on the valve bridge, the bottom of the bowl seat is abutted against the hydraulic tappet, and a limiting hole for communicating the first oil way with an oil inlet of the hydraulic tappet is arranged at the bottom of the bowl seat.
Preferably, the valve bridge is provided with a mounting hole, the hydraulic tappet is mounted in the mounting hole, and the valve bridge is also used as a tappet body of the hydraulic tappet.
Preferably, the hydraulic tappet comprises a plunger and a pressure relief assembly, a hydraulic cavity facing the opening of the pressure relief assembly is arranged in the plunger, an oil inlet of the hydraulic tappet is arranged on the plunger, the oil inlet is communicated with the hydraulic cavity and the flow limiting hole, a one-way valve opening towards the hydraulic cavity is arranged between the oil inlet and the hydraulic cavity, the pressure relief assembly comprises a pressure relief channel communicated with the hydraulic cavity, and a pressure relief control valve is arranged in the pressure relief channel.
Preferably, the pressure relief control valve comprises a valve seat, the pressure relief channel comprises a stepped hole communicated with the hydraulic cavity, the valve seat is arranged in the stepped hole, the pressure relief channel further comprises a pressure relief hole communicated with the stepped hole, a sealing conical surface is arranged between the stepped hole and the pressure relief hole, a valve core matched with the sealing conical surface is arranged between the valve seat and the pressure relief hole, and a pressure relief spring for pushing the valve core away from the sealing conical surface is arranged in the pressure relief hole.
Preferably, an oil passing gap is arranged between the valve seat and the step hole, and the oil passing gap is communicated with the hydraulic cavity and the pressure relief hole.
Preferably, the valve seat is provided with an oil passing hole for communicating the hydraulic cavity with the pressure relief hole.
Preferably, the valve core is a spherical valve core.
Preferably, the pressure relief hole communicates with the oil pan.
Preferably, an extension spring is installed in the hydraulic cavity, one end of the extension spring is fixedly connected with the inner wall of the hydraulic cavity, and the other end of the extension spring is fixedly connected with the inner wall of the mounting hole.
Preferably, a compression spring is mounted between the rocker arm and the valve bridge, surrounding the tappet connection and the bowl seat.
The beneficial effects of the application are as follows:
The hydraulic tappet assembly mechanism comprises a tappet connecting part arranged at one end of a rocker arm and a valve bridge, wherein the tappet connecting part is provided with a first oil way communicated with an engine oil way of an engine, a bowl seat is arranged at the end part of the tappet connecting part, which faces the hydraulic tappet, the hydraulic tappet is arranged on the valve bridge, the bottom of the bowl seat is abutted against the valve bridge, the bottom of the bowl seat is provided with a limiting hole communicated with the first oil way and an oil inlet of the hydraulic tappet, an oil drainage gap is formed between the bowl seat and the hydraulic tappet when an engine brakes in a cylinder, at the moment, the end face of the hydraulic tappet, which faces the bowl seat, is an inclined plane, hydraulic oil flowing out of the limiting hole flows along the inclined plane and does not flow into an oil inlet of the hydraulic tappet, the hydraulic tappet is not continuously supplied and does not stretch any more, when a brake is finished, the valve is closed, the hydraulic tappet immediately returns to a normal working state, and the assembly mechanism can well cooperate with an internal brake system of the engine to ensure the working state of the engine to keep high performance.
Drawings
The following drawings are only for purposes of illustration and explanation of the present utility model and are not intended to limit the scope of the utility model. Wherein:
FIG. 1 is a schematic diagram of a first embodiment of the present utility model;
FIG. 2 is a second schematic structural diagram of the first embodiment of the present utility model;
FIG. 3 is an enlarged view of FIG. 2 at I;
FIG. 4 is a schematic diagram of a second embodiment of the present utility model;
FIG. 5 is an enlarged view at II in FIG. 4;
FIG. 6 is a schematic view of a third embodiment of the present utility model;
FIG. 7 is an enlarged view at III in FIG. 6;
FIG. 8 is a graph of valve travel during braking of the present utility model;
In the figure, the valve comprises a rocker 11, a push rod 12, a cam 13, a valve bridge 14, a screw 15, a first oil way 16, a bowl seat 17, a limiting hole 18, a plunger 21, an oil inlet 22, a hydraulic cavity 23, a one-way valve 24, a pressure relief channel 31, a valve seat 32, a sealing conical surface 33, a valve core 34, a pressure relief spring 35, a 4-extension spring 5, a compression spring 61 and a valve rod 62.
Detailed Description
The utility model is further illustrated in the following, in conjunction with the accompanying drawings and examples. In the following detailed description, certain exemplary embodiments of the present utility model are described by way of illustration only. It is needless to say that the person skilled in the art realizes that the described embodiments may be modified in various different ways without departing from the spirit and scope of the utility model. Accordingly, the drawings and description are to be regarded as illustrative in nature and not as restrictive in scope.
As shown in fig. 1, 2 and 3, a push rod 12 is mounted at one end of a rocker arm 11, the other end of the rocker arm 11 is connected with a valve bridge 14 through the hydraulic tappet assembly mechanism, and the push rod 12 is in mating contact with a cam 13. A set of valve assemblies are respectively installed at both ends of the valve bridge 14, the valve assemblies comprise valve rods 61 for connecting the valve bridge 14 and the valves, and valve springs 62 are installed on the valve rods 61.
The hydraulic tappet assembly mechanism comprises a tappet connecting part arranged at one end of a rocker arm 11 and between a valve bridge 14, wherein a screw 15 is arranged at one end of the rocker arm 11, the screw 15 is the tappet connecting part, the screw 15 is used for adjusting a valve clearance, the screw 15 is in threaded connection with the rocker arm 11, a screw 15 can be replaced by a bolt, the tappet connecting part is provided with a first oil way 16 communicated with an engine oil way of an engine, a bowl seat 17 is arranged at the end of the tappet connecting part facing the hydraulic tappet, the hydraulic tappet is arranged on the valve bridge 14, the bottom of the bowl seat 17 is propped against the hydraulic tappet, the bowl seat 17 adopts a foot bowl seat 17, and a flow limiting hole 18 which is communicated with the first oil way 16 and the hydraulic tappet 22 is arranged at the bottom of the bowl seat 17.
The valve bridge 14 is provided with a mounting hole, the hydraulic tappet is mounted in the mounting hole, and the valve bridge 14 also serves as a tappet body of the hydraulic tappet. The hydraulic tappet comprises a plunger 21 and a pressure relief assembly, wherein the plunger 21 is slidably arranged in the mounting hole, a hydraulic cavity 23 which faces the opening of the pressure relief assembly is arranged in the plunger 21, an oil inlet 22 of the hydraulic tappet is arranged on the plunger 21, the oil inlet 22 is communicated with the hydraulic cavity 23 and the flow limiting hole 18, a one-way valve 24 which is opened towards the hydraulic cavity 23 is arranged between the oil inlet 22 and the hydraulic cavity 23, the pressure relief assembly comprises a pressure relief channel 31 which is communicated with the hydraulic cavity 23, and a pressure relief control valve is arranged in the pressure relief channel 31.
The pressure relief control valve comprises a valve seat 32, the pressure relief channel 31 comprises a stepped hole communicated with the hydraulic cavity 23, the valve seat 32 is arranged in the stepped hole, the pressure relief channel 31 further comprises a pressure relief hole communicated with the stepped hole, a sealing conical surface 33 is arranged between the stepped hole and the pressure relief hole, a valve core 34 matched with the sealing conical surface 33 is arranged between the valve seat 32 and the pressure relief hole, and a pressure relief spring 35 for pushing the valve core 34 away from the sealing conical surface 33 is arranged in the pressure relief hole. The valve core 34 is a spherical valve core 34, and the spherical valve core 34 is matched with the sealing conical surface 33.
An oil passing gap for communicating the hydraulic cavity 23 with the pressure relief hole is arranged between the valve seat 32 and the step hole. It is possible to ensure smooth flow into the relief passage 31 in the hydraulic pressure chamber 23. Or the valve seat 32 is provided with an oil passing hole (not shown in the figure) which is communicated with the hydraulic cavity 23 and the pressure relief hole, and the oil passing hole has the same function as the oil passing gap, so that the oil in the hydraulic cavity 23 can conveniently enter the pressure relief channel 31. The pressure relief hole is communicated with the oil pan.
Working principle:
When the cam 13 does not work (the cam 13 does not rotate to a working surface), since the hydraulic tappet is not acted by the opening pressure of the valve at the moment, the valve core 34 of the pressure relief control valve is propped away from the sealing conical surface 33 of the pressure relief channel 31 by the pressure relief spring 35 to form an oil leakage gap, engine oil enters the hydraulic cavity 23 through the oil inlet 22 and the one-way valve 24 and slowly leaks through the gap between the pressure relief valve core 34 and the sealing conical surface 33, at the moment, the plunger 21 of the hydraulic tappet is close to the cam 13 and the valve under the action of the engine oil pressure, the valve gap is eliminated, and the effects of expansion and contraction and the like of all parts are automatically compensated in a telescopic mode. When the cam 13 works (the cam 13 rotates to a working surface), the oil pressure of the hydraulic cavity 23 is increased, the pressure relief valve core 34 overcomes the elasticity of the pressure relief spring 35, the hydraulic cavity 23 becomes a closed cavity, and compared with a traditional hydraulic tappet (working length is shortened), no matter how the rotation speed of the engine changes, the relative position of the tappet body and the plunger 21 cannot change, and the performance of the engine is ensured.
In the braking process in the cylinder, at the moment of the action of braking force F, one valve sinks, the valve bridge 14 moves simultaneously, a drain gap is generated between the plunger 21 and the bowl seat 17, the plane where the plunger 21 contacts with the bowl seat 17 is inclined, hydraulic oil flowing into the hydraulic tappet through the bowl seat 17 is discharged from the drain gap, the hydraulic tappet is not continuously supplied with hydraulic oil, the pressure in the hydraulic cavity 23 is relatively increased, the one-way valve 24 at the oil inlet 22 of the plunger 21 is closed, the hydraulic tappet is not stretched any more, the valve gap is not changed, F is zero after the braking is finished, the valve is closed under the action of valve spring force, the bowl seat 17 is continuously supplied with the hydraulic tappet, and the hydraulic tappet is restored to the normal working state. The hydraulic tappet can eliminate the valve clearance in the subsequent intake stroke and exhaust stroke, and the valve can be normally opened.
In the process of releasing the pressure of the hydraulic oil from the oil release gap, the flow limiting hole 18 has two functions, namely, the oil quantity of the released oil is reduced, the oil quantity flowing out of the flow limiting hole 18 can be controlled to be released through the oil release gap, and excessive oil cannot enter the hydraulic cavity 23 of the hydraulic tappet to cause the hydraulic tappet to stretch.
Compared with the prior art, the hydraulic tappet has the advantages that the return spring in the hydraulic cavity 23 of the hydraulic tappet is omitted, and the hydraulic tappet is simpler in structure because the extension is only provided by the pressure of hydraulic oil. The assembly mechanism can be well matched with an in-cylinder braking system of the engine, and the engine is ensured to maintain a high-performance working state.
The difference between this embodiment and the first embodiment is that, as shown in fig. 4 and 5, an extension spring 4 is installed in the hydraulic chamber 23, one end of the extension spring 4 is fixedly connected with the inner wall of the hydraulic chamber 23, and the other end of the extension spring 4 is fixedly connected with the inner wall of the mounting hole.
In the first embodiment, the hydraulic tappet length is kept unchanged by using the pressure of the hydraulic oil in the hydraulic cavity 23, in this embodiment, the extension spring 4 is installed between the plunger 21 and the valve bridge 14, that is, the extension spring 4 is installed in the hydraulic cavity 23, and when the pressure in the hydraulic cavity 23 increases, the extension spring 4 can apply elastic force to the plunger 21, so that the hydraulic tappet length is kept unchanged, and the valve clearance is ensured to be unchanged.
The present embodiment is different from the first embodiment in that, as shown in fig. 6 and 7, a compression spring 5 is installed between the rocker arm 11 and the valve bridge 14 to surround the tappet connection portion and the bowl seat 17.
In this embodiment, the compression spring 5 reaches the maximum state in the moment of braking, and the oil drainage effect is ensured.
Fig. 8 is a graph of throttle displacement versus time or crank angle during operation, from which the operating state of the valve during normal engine operation and in-cylinder braking can be clearly seen.
The foregoing has shown and described the basic principles, main features and advantages of the present utility model. It will be understood by those skilled in the art that the present utility model is not limited to the embodiments described above, and that the above embodiments and descriptions are merely illustrative of the principles of the present utility model, and various changes and modifications may be made without departing from the spirit and scope of the utility model, which is defined in the appended claims.
Claims (10)
1. The hydraulic tappet assembly mechanism comprises a tappet connecting portion arranged at one end of a rocker arm and a valve bridge, wherein the tappet connecting portion is provided with a first oil way communicated with an engine oil way of an engine, a bowl seat is arranged at the end portion, facing the hydraulic tappet, of the tappet connecting portion, the hydraulic tappet is arranged on the valve bridge, and the bottom of the bowl seat is abutted against the hydraulic tappet.
2. The hydraulic tappet assembly mechanism of claim 1, wherein the valve bridge has mounting holes, the hydraulic tappet is mounted in the mounting holes, and the valve bridge doubles as a tappet body of the hydraulic tappet.
3. The hydraulic tappet assembly mechanism of claim 2, wherein the hydraulic tappet comprises a plunger and a pressure relief assembly, a hydraulic cavity facing the opening of the pressure relief assembly is arranged in the plunger, an oil inlet of the hydraulic tappet is arranged on the plunger, the oil inlet is communicated with the hydraulic cavity and the flow limiting hole, a one-way valve opening towards the hydraulic cavity is arranged between the oil inlet and the hydraulic cavity, the pressure relief assembly comprises a pressure relief channel communicated with the hydraulic cavity, and a pressure relief control valve is arranged in the pressure relief channel.
4. The hydraulic tappet assembly mechanism of claim 3, wherein the pressure relief control valve comprises a valve seat, the pressure relief channel comprises a stepped hole communicated with the hydraulic cavity, the valve seat is arranged in the stepped hole, the pressure relief channel further comprises a pressure relief hole communicated with the stepped hole, a sealing conical surface is arranged between the stepped hole and the pressure relief hole, a valve core matched with the sealing conical surface is arranged between the valve seat and the pressure relief hole, and a pressure relief spring for pushing the valve core away from the sealing conical surface is arranged in the pressure relief hole.
5. The hydraulic tappet assembly device of claim 4, wherein an oil passage gap is provided between the valve seat and the stepped bore to communicate the hydraulic chamber and the relief bore.
6. The hydraulic tappet assembly device as set forth in claim 4, wherein said valve seat is provided with an oil passage hole communicating said hydraulic chamber with said relief hole.
7. The hydraulic tappet assembly mechanism of claim 4, wherein the spool is a ball spool.
8. The hydraulic lifter assembly mechanism of claim 4, wherein the relief aperture communicates with the oil pan.
9. The hydraulic tappet assembly device as set forth in any one of claims 3-8, wherein an extension spring is installed in the hydraulic chamber, one end of the extension spring is fixedly connected with an inner wall of the hydraulic chamber, and the other end of the extension spring is fixedly connected with an inner wall of the mounting hole.
10. The hydraulic lifter assembly mechanism according to any one of claims 3 to 8, characterized in that a compression spring is installed between the rocker arm and the valve bridge, surrounding the lifter connection and the bowl.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202422287562.0U CN223089378U (en) | 2024-09-19 | 2024-09-19 | Hydraulic tappet assembly mechanism |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202422287562.0U CN223089378U (en) | 2024-09-19 | 2024-09-19 | Hydraulic tappet assembly mechanism |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN223089378U true CN223089378U (en) | 2025-07-11 |
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ID=96295790
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202422287562.0U Active CN223089378U (en) | 2024-09-19 | 2024-09-19 | Hydraulic tappet assembly mechanism |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN223089378U (en) |
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- 2024-09-19 CN CN202422287562.0U patent/CN223089378U/en active Active
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