GB2568621A - Variable valve tappet - Google Patents
Variable valve tappet Download PDFInfo
- Publication number
- GB2568621A GB2568621A GB1903051.9A GB201903051A GB2568621A GB 2568621 A GB2568621 A GB 2568621A GB 201903051 A GB201903051 A GB 201903051A GB 2568621 A GB2568621 A GB 2568621A
- Authority
- GB
- United Kingdom
- Prior art keywords
- tappet
- oil
- base
- valve
- push rod
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
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Classifications
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01L—CYCLICALLY OPERATING VALVES FOR MACHINES OR ENGINES
- F01L1/00—Valve-gear or valve arrangements, e.g. lift-valve gear
- F01L1/12—Transmitting gear between valve drive and valve
- F01L1/14—Tappets; Push rods
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01L—CYCLICALLY OPERATING VALVES FOR MACHINES OR ENGINES
- F01L1/00—Valve-gear or valve arrangements, e.g. lift-valve gear
- F01L1/12—Transmitting gear between valve drive and valve
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01L—CYCLICALLY OPERATING VALVES FOR MACHINES OR ENGINES
- F01L1/00—Valve-gear or valve arrangements, e.g. lift-valve gear
- F01L1/20—Adjusting or compensating clearance
- F01L1/22—Adjusting or compensating clearance automatically, e.g. mechanically
- F01L1/24—Adjusting or compensating clearance automatically, e.g. mechanically by fluid means, e.g. hydraulically
- F01L1/245—Hydraulic tappets
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01L—CYCLICALLY OPERATING VALVES FOR MACHINES OR ENGINES
- F01L1/00—Valve-gear or valve arrangements, e.g. lift-valve gear
- F01L1/20—Adjusting or compensating clearance
- F01L1/22—Adjusting or compensating clearance automatically, e.g. mechanically
- F01L1/24—Adjusting or compensating clearance automatically, e.g. mechanically by fluid means, e.g. hydraulically
- F01L1/245—Hydraulic tappets
- F01L1/25—Hydraulic tappets between cam and valve stem
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01L—CYCLICALLY OPERATING VALVES FOR MACHINES OR ENGINES
- F01L1/00—Valve-gear or valve arrangements, e.g. lift-valve gear
- F01L1/34—Valve-gear or valve arrangements, e.g. lift-valve gear characterised by the provision of means for changing the timing of the valves without changing the duration of opening and without affecting the magnitude of the valve lift
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01L—CYCLICALLY OPERATING VALVES FOR MACHINES OR ENGINES
- F01L13/00—Modifications of valve-gear to facilitate reversing, braking, starting, changing compression ratio, or other specific operations
- F01L13/0015—Modifications of valve-gear to facilitate reversing, braking, starting, changing compression ratio, or other specific operations for optimising engine performances by modifying valve lift according to various working parameters, e.g. rotational speed, load, torque
- F01L13/0031—Modifications of valve-gear to facilitate reversing, braking, starting, changing compression ratio, or other specific operations for optimising engine performances by modifying valve lift according to various working parameters, e.g. rotational speed, load, torque by modification of tappet or pushrod length
Landscapes
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Valve Device For Special Equipments (AREA)
- Valve-Gear Or Valve Arrangements (AREA)
Abstract
A variable valve tappet, comprising a tappet base (9) and a holder (12). The tappet base (9) is of a cylinder structure having a T-shaped hollow cylindrical groove provided on an upper portion thereof, and a tappet sleeve (14) being of a hollow cylinder structure is fit over the tappet base (9). The tappet further comprises a valve push rod base (16) being of a cylinder structure. An additional lift cavity (20) is formed between the lower surface of the valve push rod base (16) and the tappet base (9). The holder (12) is of a hollow cylindrical structure. The upper surface of the valve push rod base (16) extends outwards along the outer edge of the cylinder to match the inner surface of the holder (12), so that an oil storage cavity (17) is formed between the upper surface of the valve push rod base (16) and the inner surface of the holder (12). An oil pumping cavity (11) is formed among the outer surface of the holder (12), the inner surface of the tappet sleeve (14), and the tappet base (9). A tappet spring (19) is provided in the oil pumping cavity (11) outside the valve push rod base (16). The tappet sleeve (14) is provided with an oil inlet (8) connected to an oil supply system, and an oil return port (22) connected to an oil return system. The upper surface of the valve push rod base (16) is connected to a valve push rod (15). A cam (1) is provided directly below the tappet base (9). The variable valve tappet can achieve valve timing and lift control in operating situations where an engine have different speeds, and features low costs, high applicability, and high stability.
Description
Technical Field
The present invention relates to the technical field of engine valve trains, in particular to a variable valve tappet.
Background Art
Most of the traditional valve trains use a camshaft to drive the intake and exhaust valves, and the timing and control of the valve phase are achieved by way of the mechanical transmission between crankshafts and camshafts, and camshafts and the valves. While the design of a cam is selected according to the comprehensive evaluation value of each indicator of the engine under various working conditions, it can only meet the performance requirements of the engine under certain working conditions, and cannot reach the optimal performance of the engine under various working conditions. Compared to the traditional engine valve train technology, variable valve technology is able to provide optimal valve timing or lift under the working conditions of various engine speeds so as to meet the requirements of engine dynamics, economy and emissions. Faced with two major problems of energy saving, emission reduction and environmental pollution, variable valve technology has become one of the key technologies for internal combustion engine to achieve efficient and clean combustion technology that have been studied by many researchers. However, most of the existing variable valve mechanisms can only achieve certain local functions such as early valve opening, late closing and the like, and cannot be continuously adjusted under the full working conditions of the engine, thereby limiting the optimal performance of the engine.
Summary of the Invention
The present invention provides a variable valve tappet capable of achieving valve timing and lift control under working conditions of various engine speeds.
The technical solution employed by the present invention is as follows: a variable valve tappet, comprising a tappet base and a holder; the tappet base is of a cylinder structure having a T-shaped hollow cylindrical groove provided on an upper portion thereof, a tappet sleeve being of a hollow cylindrical structure is fitted over an outer side of the tappet base, an outer surface of the tappet base fits with an inner surface of the tappet sleeve; the tappet further comprises a valve push rod base being of a cylindrical structure, a lower outer surface thereof fits with an inner surface of a small cylindrical groove of a hollow portion inside the tappet base, an additional lift cavity is formed between the lower surface thereof and the tappet base, the structure of the holder is one of a hollow cylinder, an upper surface thereof extends outwards along an outer edge of the cylinder to connect to the inner surface of the tappet sleeve, a lower surface thereof extends inwards along an inner edge of the cylinder to fit with an outer surface of the valve push rod base; an upper surface of the valve push rod base extends outwards along an outer edge of the cylinder to fit with an inner surface of the holder, and form an oil storage cavity with the inner surface of the holder; the additional lift cavity communicates with the oil storage cavity; an outer surface of the holder, the inner surface of the tappet sleeve and the tappet base therebetween form an oil pumping cavity; a tappet spring is provided in the oil pumping cavity outside the valve push rod base; the tappet sleeve is provided with an oil inlet port in communication with an oil supply system and an oil return port in communication with an oil return system; the oil inlet port communicates with the oil pumping cavity, the oil return port communicates with the additional lift cavity, the oil pumping cavity communicates with the oil storage cavity via an oil inlet check valve; the tappet base is further provided with a pressure limiting oil passage in communication with the additional lift cavity; the upper surface of the valve push rod base is connected to a valve push rod; and a cam is provided directly below the tappet base.
Further, the diameter of a lower portion of the valve push rod base is smaller than the diameter of an upper portion thereof, so as to form a two-stepped cylinder; an outer surface of the lower portion of the two-stepped cylinder fits with the inner surface of a small cylindrical groove of a hollow portion inside the tappet base, and an outer surface of the upper portion of the two-stepped cylinder fits with a portion of a lower surface of the holder extending inwards along the inner edge of the cylinder.
Further, the upper surface of the valve push rod base is provided with a “concave” spherical surface recessing into an interior thereof, which fits with the lower surface of the valve push rod.
Further, the tappet base is provided with two oil grooves which are not connected to each other along a moving direction thereof, wherein one of the oil grooves is connected to the oil inlet port, and an upper end thereof is connected to the oil pumping cavity via an oil inlet oil passage on the tappet base; the other oil groove is connected to the oil return port, and an upper end thereof is connected to the additional lift cavity via an oil return oil passage on the tappet base.
Further, a portion of the surface of the holder extending inwards along the inner edge of the cylinder is provided with the oil inlet check valve in communication with the oil pumping cavity and the oil storage cavity.
Further, the pressure limiting oil passage is provided with a pressure limiting valve.
Further, the holder is connected to the tappet sleeve via a fixation screw.
Further, the valve push rod base is provided with a hydraulic oil passage, and the hydraulic oil passage is connected to the oil storage cavity and the additional lift cavity.
Further, the tappet sleeve, the tappet base, the holder and the valve push rod base are arranged coaxially.
The present invention has the following advantageous effects:
(1) The present invention can achieve the valve timing and lift control under working conditions of various engine speeds.
(2) In the present invention, the work required for the oil pressure for generating an additional lift is provided by the motion of a cam, so as to eliminate the need for an additional high-pressure oil pump, thereby simplifying the system and saving costs;
(3) In the present invention, by way of changing the volumes of the oil storage cavity and the additional lift cavity, the additional lift value at the maximum valve lift time can be dynamically adjusted, so as to protect the valve assembly and maximise the time-area value of the valve lift curve.
(4) The present invention can be applied to various types of valve control mechanisms, and thus has high applicability.
(5) In the present invention, the additional lift curve depends on the mechanical structure, the oil inlet solenoid valve and the return oil solenoid valve, and thus has high reliability.
Brief Description of the Drawings
Figure 1 is a schematic view of the structure of the present invention.
In the figure, 1- cam, 2- oil pan, 3- engine oil cleaning filter, 4- low pressure oil pump, 5oil inlet solenoid valve, 6- pressure regulation valve, 7- overflow valve, 8- oil inlet port, 9- tappet base, 10- oil inlet oil passage, 11- oil pumping cavity, 12- holder, 13- positioning screw, 14tappet sleeve, 15- valve push rod, 16- valve push rod base, 17- oil storage cavity, 18- oil inlet check valve, 19- tappet spring, 20- additional lift cavity, 21- oil return oil passage, 22- oil return port, 23- oil return solenoid valve, 24- pressure limit valve, 25- pressure limiting oil passage.
Description of the Embodiments
The present invention will be further described below in reference with the accompanying drawings and specific embodiments.
As shown in Figure 1, variable valve tappet, characterised in that: the variable valve tappet comprises a tappet base 9 and a holder 12; the tappet base 9 is of a cylinder structure having a T-shaped (in other words an inverted “ ιπι ” shaped) hollow cylindrical groove or tank provided on an upper portion thereof, a tappet sleeve 14 being of a hollow cylindrical structure is fitted over an outer side of the tappet base 9, an outer surface of the tappet base 9 fits with an inner surface of the tappet sleeve 14; the tappet further comprises a valve push rod base 16 being of a cylindrical structure, a lower outer surface thereof fits with inner surface of a small cylindrical groove or tank of a hollow portion inside the tappet base 9, an additional lift cavity 20 is formed between the lower surface thereof and the tappet base 9, the structure of the holder 12 is one of a hollow cylinder, an upper surface thereof extends outwards along an outer edge of the cylinder to connect to the inner surface of the tappet sleeve 14, a lower surface thereof extends inwards along an inner edge of the cylinder to fit with an outer surface of the valve push rod base 16; an upper surface of the valve push rod base 16 extends outwards along an outer edge of the cylinder to fit with an inner surface of the holder 12, and form an oil storage cavity 17 with the inner surface of the holder 12; the additional lift cavity 20 communicates with the oil storage cavity 17; an outer surface of the holder 12, the inner surface of the tappet sleeve 14 and the tappet base 9 therebetween form an oil pumping cavity 11; a tappet spring 19 is provided in the oil pumping cavity 11 outside the valve push rod base 16; the tappet sleeve 14 is provided with an oil inlet port 8 in communication with an oil supply system and an oil return port 22 in communication with an oil return system; the oil inlet port 8 communicates with the oil pumping cavity 11, the oil return port 22 communicates with the additional lift cavity 20, the oil pumping cavity 11 communicates with the oil storage cavity 17 via an oil inlet check valve 18; the tappet base 9 is further provided with a pressure limiting oil passage 25 in communication with the additional lift cavity 20; the upper surface of the valve push rod base 16 is connected to a valve push rod 15; and a cam 1 is provided directly below the tappet base 9.
Further, the diameter of a lower portion of the valve push rod base 16 is smaller than the diameter of an upper portion thereof, so as to form a two-stepped cylinder; an outer surface of the lower portion of the two-stepped cylinder fits with the inner surface of a small cylindrical groove or tank of a hollow portion inside the tappet base 9, and an outer surface of the upper portion of the two-stepped cylinder fits with a portion of a lower surface of the holder 12 extending inwards along the inner edge of the cylinder; the upper surface of the valve push rod base 16 extends outwards along the outer edge of the two-stepped cylinder and forms a seal surface with the inner surface of the holder 12, the outer surface of the upper portion of the twostepped cylinder and the portion of the lower surface of the holder 12 extending inwards along the inner edge of the cylinder form a seal surface, and outer surface of the lower portion of the two-stepped cylinder and the inner surface of the small cylinder groove of the hollow portion inside the tappet base 9 also form a seal surface.
Further, the upper surface of the valve push rod base 16 is provided with a “concave” spherical surface recessing into an interior thereof, which fits with the lower surface of the valve push rod 15.
Further, the tappet base 9 is provided with two oil grooves which are not connected to each other along a moving direction thereof, wherein one of the oil grooves is connected to the oil inlet port 8, and an upper end thereof is connected to the oil pumping cavity 11 via an oil inlet oil passage 10 on the tappet base 9; the other oil groove is connected to the oil return port 22, and an upper end thereof is connected to the additional lift cavity 20 via an oil return oil passage 21 on the tappet base 9. During the moving course of the tappet base 9, the oil groove keeps in communication with the oil return port 22. In addition, two ends of the oil groove are arc shaped.
Further, a portion of the surface of the holder 12 extending inwards along the inner edge of the cylinder is provided with the oil inlet check valve 18 in communication with the oil pumping cavity 11 and the oil storage cavity 17. The oil inlet check valve 18 provided herein can ensure that the hydraulic oil is only allowed to enter oil storage cavity 17 through the oil pumping cavity 11, and is not allowed to flow back.
Further, the pressure limiting oil passage 25 is provided with a pressure limiting valve 24. In this way, it is ensured that the additional lift generated by the additional lift chamber 20 is not greater than the maximum valve additional lift in any case.
Further, the holder 12 is connected to the tappet sleeve 14 via a fixation screw 13. The tappet sleeve 14 is machined to have a threaded through hole, and the portion on the upper surface of the holder 12 extending outwards along the outer edge of the cylinder is provided with a threaded hole that fits the threaded through hole of the tappet sleeve 14.
Further, the valve push rod base 16 is provided with a hydraulic oil passage, and the hydraulic oil passage is connected to the oil storage cavity 17 and the additional lift cavity 20. In this way, it is ensured that the oil storage cavity 17 is in communication with the additional lift cavity 20 under any condition.
Further, the tappet sleeve 14, the tappet base 9, the holder 12 and the valve push rod base 16 are arranged coaxially.
When in use, the oil inlet port 8 is connected to the oil inlet system through the oil inlet solenoid valve 5, the oil return port 22 is connected to the oil return system through the oil return solenoid valve 23; in which the oil inlet system includes the engine oil cleaning filter 3 and the overflow valve 7 which are connected to the oil pan 2, the engine oil cleaning filter 3 is connected to the low pressure oil pump 4, the low pressure oil pump 4 is connected to the pressure regulation valve 6, and the pressure regulation valve 6 is connected to the oil inlet solenoid valve 5.
In operation, the pressure limit value of the pressure limit valve 24 is obtained through the calculation method as follows:
In the above equation, k is the stiffness of the valve spring, Δ/ is the maximum additional lift of the valve, 5 is the force receiving area of the valve push rod 15 in the additional lift cavity 20, L is the original lift of the valve, Fk is the spring force when the total lift of the valve is maximum, Po is the pressure limit value of the pressure limit valve 24. In use, it only needs that the pressure limit value of the pressure limit valve 24 is only required to be slightly greater than Po.
The variable valve tappet working process includes the following parts:
I. The additional lift generation process with the target value being the maximum additional lift value
1. The oil inlet solenoid valve 5 and the oil return solenoid valve 23 are first opened, when the tappet base 9 descends with the cam 1, since the tappet sleeve 14 and the holder 12 are fixedly connected, a negative pressure is formed in the oil pumping cavity 11 due to the increase of its volume Vi, and the hydraulic oil fills the oil pumping cavity 11 via the oil supply system, the oil inlet port 8 and the oil inlet oil passage 10; the valve push rod base 16 descends with the tappet base 9, and the volume V2 of the oil storage cavity 17 is reduced, so the hydraulic oil in the oil storage cavity 17 flows towards the additional lift cavity 20, and then enters the oil return system via the oil return oil passage 21; during this process, the volume V3 of the additional lift cavity 20 remains unchanged, and the valve lift line depends on the lift process curve the cam.
2. The oil inlet solenoid valve 5 and the oil return solenoid valve 23 are then closed, and the tappet base 9 moves upward under the action of the cam 1, thereby “pressing” the oil pumping cavity 11, and the volume Vi of the oil pumping cavity 11 is reduced, and the pressure pi is increased, so the hydraulic oil enters the oil storage cavity 17 and the additional lift cavity 20 via the oil inlet check valve 18, and the volume V2 and the pressure P2 of the oil storage cavity 17 increase, and the volume V3 and the pressure ps of the additional lift cavity 20 increase as well; so the valve push rod base 16 and the tappet base 9 are relatively displaced, that is, an additional lift is generated; after the valve reaches the maximum additional lift, the pressure p3 of the additional lift cavity 20 exceeds the opening pressure value of the pressure limit valve 24, so the pressure limit valve 24 is opened, and the hydraulic oil flows through the pressure limit valve and returns to the oil return system, and the additional lift maintains dynamic balance.
3. When the cam 1 descends, the volume Vi of the oil pumping cavity 11 increases, and the hydraulic oil enters the oil pumping cavity 11 through the oil supply system, at this time point, the volume V2 of the oil storage cavity 17 decreases, so the hydraulic oil flows to the additional lift cavity 20 through the oil storage cavity 17, the volume V2 of the additional lift cavity 20 increases, and the valve additional lift slowly increases;
The valve additional lift increase amount Δ/s depends on S2/S3, where S2 is the equivalent area of the oil storage cavity 17, and S3 is the equivalent area of the additional lift cavity 20, when the oil return solenoid valve 23 is opened, the hydraulic oil enters the oil return system and flows back to the hydraulic oil groove, so the valve additional lift disappears.
II. Additional lift generation process with target value less than the maximum additional lift value
1. The oil inlet solenoid valve 5 and the oil return solenoid valve 23 are first opened, when the tappet base 9 descends with the cam 1, since the tappet sleeve 14 and the holder 12 are fixedly connected, a negative pressure is formed in the oil pumping cavity 11 due to the increase of its volume Vi, and the hydraulic oil fills the oil pumping cavity 11 via the oil supply system, the oil inlet port 8 and the oil inlet oil passage 10; the valve push rod base 16 descends, the volume U of the oil storage cavity 17 is reduced, so the hydraulic oil in the oil storage cavity 17 flows towards the additional lift cavity 20, and then enters the oil return system via the oil return oil passage 21; during this process, the volume V3 of the additional lift cavity 20 remains unchanged, and the valve lift line depends on the lift process curve the cam.
2. The oil inlet solenoid valve 5 and the oil return solenoid valve 23 are then closed, and the tappet base 9 moves upward under the action of the cam 1, thereby “pressing” the oil pumping cavity 11, and the volume Vi of the oil pumping cavity 11 is reduced, and the pressure pi is increased, so the hydraulic oil enters the oil storage cavity 17 and the additional lift cavity 20 via the oil inlet check valve 18, and the volume V2 and the pressure P2 of the oil storage cavity 17 increase, and the volume V3 and the pressure ps of the additional lift cavity 20 increase as well; so the valve push rod base 16 and the tappet base 9 are relatively displaced, that is, an additional lift is generated; after the valve reaches the target additional lift, the oil inlet solenoid valve 5 is opened, the cam 1 continues to ascend, and the hydraulic oil in the oil pumping cavity 11 flows back to the hydraulic oil groove via the oil inlet system, at this time point, the volume V2 of the oil storage cavity 17 increases, and the hydraulic oil flows into the oil storage cavity 17 via the additional lift cavity 20, the volume V3 of the additional lift cavity 20 decreases, so the valve additional lift is slowly reduced; from the following equation:
AV 2 - AV3 χ,Δ/.» ~ , that is, it can be seen that the valve additional lift reduction amount ΔΛ depends on S2/S3.
3. When the cam 1 descends, the volume Vi of the oil pumping cavity 11 increases, and the hydraulic oil enters the oil pumping cavity 11 through the oil supply system, at this time point, the volume V2 of the oil storage cavity 17 decreases, so the hydraulic oil flows to the additional lift cavity 20 through the oil storage cavity 17, the volume V3 of the additional lift cavity 20 increases, and the valve additional lift slowly increases;
Thus it can be known that the valve additional lift increase amount Δ/3 depends on S2/S3. When the oil return solenoid valve 23 is opened, the valve additional lift disappears.
III. No additional lift is generated before cam 1 reaches a stop point and additional lift is generated in the descending phase of cam 1
1. First, the oil inlet solenoid valve 5 and the oil return solenoid valve 23 are opened. When the tappet base 9 descends with the cam 1, since the tappet sleeve 14 and the holder 12 are fixedly connected, a negative pressure is formed in the oil pumping cavity 11 due to the increase of its volume Vi. The hydraulic oil fills the oil pumping cavity 11 via the oil supply system, the oil inlet port 8 and the oil inlet oil passage 10. The valve push rod base 16 descends, the volume V2 of the oil storage cavity 17 is reduced, so the hydraulic oil in the oil storage cavity 17 flows towards the additional lift cavity 20, and then enters the oil return system via the oil return oil passage 21. During this process, the volume V3 of the additional lift cavity 20 remains unchanged, and the valve lift line depends on the lift process curve the cam.
2. The oil inlet solenoid valve 5 is opened and the oil return solenoid valve 23 is closed, the tappet base 9 moves upward under the action of the cam 1, thereby “pressing” the oil pumping cavity 11. The volume Vi of the oil pumping cavity 11 is reduced, and the pressure pi is maintained to a pressure value close to that of the hydraulic oil groove. The valve push rod base 16 moves upward under the pushing of the tappet base 9, the volume V2 of the oil storage chamber increases, while the volume V3 of the additional lift cavity 20 remains unchanged, so the pressure p2 becomes smaller. A part of the hydraulic oil within the oil pumping cavity 11 is drawn to the oil storage chamber 17 through the oil inlet check valve 18, and the valve push rod seat 16 and the tappet base 9 are not displaced relatively, that is, no additional lift is generated until the cam 1 lift reaches a maximum value.
3. When the cam 1 descends, the volume Vi of the oil pumping cavity 11 increases, and the hydraulic oil enters the oil pumping cavity 11 through the oil supply system, at this time point, the volume V2 of the oil storage cavity 17 decreases, so the hydraulic oil flows to the additional lift cavity 20 through the oil storage cavity 17, the volume V3 of the additional lift cavity 20 increases, and the valve additional lift slowly increases;
Thus, it can be known that the valve additional lift increase amount Δ/s is dependent on S2/S3. When the oil return solenoid valve 23 is opened, the valve additional lift disappears.
IV. No additional lift is generated
In the case when the additional lift is not required to be generated, the oil inlet solenoid valve 5 and the oil return solenoid valve 23 are kept open, and the valve operates according to the cam 1 type line of the original machine.
The present invention can achieve the valve timing and lift control under working conditions with different engine speeds, and the work required for generating the oil pressure of the additional lift is provided by the movement of the cam 1 without an additional high-pressure oil pump, which simplifies the system and saves costs. The additional lift curve depends on the mechanical structure and the oil inlet solenoid valve and the oil return solenoid valve, and the reliability is high; moreover, by means of designing suitable areas of the oil storage cavity 17 and the additional lift cavity 20, the additional lift at the time point of the maximum valve lift can be dynamically adjusted, such that the valve train components are protected, so as to protect the valve assembly and maximise the time area value of the valve lift curve. In addition, the present invention can be applied to various types of valve control mechanisms with high applicability.
The above is only some preferred embodiments of the present invention, and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.
Claims (9)
1. A variable valve tappet, characterised in that: the variable valve tappet comprises a tappet base (9) and a holder (12); the tappet base (9) is of a cylinder structure having a T-shaped hollow cylindrical groove provided on an upper portion thereof, a tappet sleeve (14) being of a hollow cylindrical structure is fitted over an outer side of the tappet base (9), an outer surface of the tappet base (9) fits with an inner surface of the tappet sleeve (14); the tappet further comprises a valve push rod base (16) being of a cylindrical structure, a lower outer surface thereof fits with an inner surface of a small cylindrical groove of a hollow portion inside the tappet base (9), an additional lift cavity (20) is formed between the lower surface thereof and the tappet base (9), the structure of the holder (12) is one of a hollow cylinder, an upper surface thereof extends outwards along an outer edge of the cylinder to connect to the inner surface of the tappet sleeve (14), a lower surface thereof extends inwards along an inner edge of the cylinder to fit with an outer surface of the valve push rod base (16); an upper surface of the valve push rod base (16) extends outwards along an outer edge of the cylinder to fit with an inner surface of the holder (12), and form an oil storage cavity (17) with the inner surface of the holder (12); the additional lift cavity (20) communicates with the oil storage cavity (17); an outer surface of the holder (12), the inner surface of the tappet sleeve (14), and the tappet base (9) therebetween form an oil pumping cavity (11); a tappet spring (19) is provided in the oil pumping cavity (11) outside the valve push rod base (16); the tappet sleeve (14) is provided with an oil inlet port (8) in communication with an oil supply system and an oil return port (22) in communication with an oil return system; the oil inlet port (8) communicates with the oil pumping cavity (11), the oil return port (22) communicates with the additional lift cavity (20), the oil pumping cavity (11) communicates with the oil storage cavity (17) via an oil inlet check valve (18); the tappet base (9) is further provided with a pressure limiting oil passage (25) in communication with the additional lift cavity (20); the upper surface of the valve push rod base (16) is connected to a valve push rod (15); and a cam (1) is provided directly below the tappet base (9).
2. A variable valve tappet according to claim 1, characterised in that the diameter of a lower portion of the valve push rod base (16) is smaller than the diameter of an upper portion thereof, so as to form a two-stepped cylinder; an outer surface of the lower portion of the two-stepped cylinder fits with the inner surface of a small cylindrical groove of a hollow portion inside the tappet base (9), and an outer surface of the upper portion of the twostepped cylinder fits with a portion of a lower surface of the holder (12) extending inwards along the inner edge of the cylinder.
3. A variable valve tappet according to claim 1, characterised in that the upper surface of the valve push rod base (16) is provided with a “concave” spherical surface recessing into an interior thereof, which fits with the lower surface of the valve push rod (15).
4. A variable valve tappet according to claim 1, characterised in that the tappet base (9) is provided with two oil grooves which are not connected to each other along a moving direction thereof, wherein one of the oil grooves is connected to the oil inlet port (8), and an upper end thereof is connected to the oil pumping cavity (11) via an oil inlet oil passage (10) on the tappet base (9); the other oil groove is connected to the oil return port (22), and an upper end thereof is connected to the additional lift cavity (20) via an oil return oil passage (21) on the tappet base (9).
5. A variable valve tappet according to claim 1, characterised in that a portion of the surface of the holder (12) extending inwards along the inner edge of the cylinder is provided with the oil inlet check valve (18) in communication with the oil pumping cavity (11) and the oil storage cavity (17).
6. A variable valve tappet according to claim 1, characterised in that the pressure limiting oil passage (25) is provided with a pressure limiting valve (24).
7. A variable valve tappet according to claim 1, characterised in that the holder (12) is connected to the tappet sleeve (14) via a fixation screw (13).
8. A variable valve tappet according to claim 1, characterised in that the valve push rod base (16) is provided with a hydraulic oil passage, and the hydraulic oil passage is connected to the oil storage cavity (17) and the additional lift cavity (20).
5
9. A variable valve tappet according to claim 1, characterised in that the tappet sleeve (14), the tappet base (9), the holder (12) and the valve push rod base (16) are arranged coaxially.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201610841364.1A CN106285811B (en) | 2016-09-22 | 2016-09-22 | A kind of changeable air valve tappet |
| PCT/CN2016/102665 WO2018053892A1 (en) | 2016-09-22 | 2016-10-20 | Variable valve tappet |
Publications (3)
| Publication Number | Publication Date |
|---|---|
| GB201903051D0 GB201903051D0 (en) | 2019-04-24 |
| GB2568621A true GB2568621A (en) | 2019-05-22 |
| GB2568621B GB2568621B (en) | 2019-10-09 |
Family
ID=57712651
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB1903051.9A Expired - Fee Related GB2568621B (en) | 2016-09-22 | 2016-10-20 | Variable valve tappet |
Country Status (4)
| Country | Link |
|---|---|
| CN (1) | CN106285811B (en) |
| CA (1) | CA3034548C (en) |
| GB (1) | GB2568621B (en) |
| WO (1) | WO2018053892A1 (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN116201620B (en) * | 2023-01-31 | 2024-05-17 | 重庆长安汽车股份有限公司 | Hydraulic tappet, engine and vehicle |
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| GB566959A (en) * | 1944-06-16 | 1945-01-22 | Thomas Hindle | Improvements in tappet mechanism for actuating poppet or like valves for internal combustion and other engines |
| GB627281A (en) * | 1947-09-18 | 1949-08-04 | Bernard Michael Francis Samuel | Improvements in or relating to hydraulic tappets |
| JPS54155309A (en) * | 1978-05-27 | 1979-12-07 | Nissan Motor Co Ltd | Valve moving system for internal combustion engine |
| US4258671A (en) * | 1978-03-13 | 1981-03-31 | Toyota Jidosha Kogyo Kabushiki Kaisha | Variable valve lift mechanism used in an internal combustion engine |
| JPS59147806A (en) * | 1983-02-10 | 1984-08-24 | Isuzu Motors Ltd | Valve opening and closing control device in internal-combustion engine |
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| CN104564206A (en) * | 2015-01-23 | 2015-04-29 | 吉林大学 | Cam-driven hydraulic fully variably valve mechanism of internal combustion engine |
| CN206071662U (en) * | 2016-09-22 | 2017-04-05 | 西华大学 | A kind of changeable air valve tappet |
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| DE19804323A1 (en) * | 1998-02-04 | 1999-08-05 | Schaeffler Waelzlager Ohg | Motor vehicle gas change valve tappet switching |
| US6357406B1 (en) * | 2000-11-22 | 2002-03-19 | Borgwarner Inc. | Variable valve actuation system |
| KR100534833B1 (en) * | 2004-03-26 | 2005-12-08 | 현대자동차주식회사 | A variable valve lift apparatus of engine in automobile |
| CN103742216A (en) * | 2014-01-24 | 2014-04-23 | 赵迎生 | Lift-variable hydraulic tappet |
| CN104454070B (en) * | 2014-10-27 | 2017-03-01 | 中北大学 | A kind of electric-controlled hydraulic governor motion of the valve stroke continuous variable based on camshaft |
| CN104481625A (en) * | 2014-11-13 | 2015-04-01 | 浙江师范大学 | Variable valve timing system |
-
2016
- 2016-09-22 CN CN201610841364.1A patent/CN106285811B/en active Active
- 2016-10-20 GB GB1903051.9A patent/GB2568621B/en not_active Expired - Fee Related
- 2016-10-20 CA CA3034548A patent/CA3034548C/en not_active Expired - Fee Related
- 2016-10-20 WO PCT/CN2016/102665 patent/WO2018053892A1/en active Application Filing
Patent Citations (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB566959A (en) * | 1944-06-16 | 1945-01-22 | Thomas Hindle | Improvements in tappet mechanism for actuating poppet or like valves for internal combustion and other engines |
| GB627281A (en) * | 1947-09-18 | 1949-08-04 | Bernard Michael Francis Samuel | Improvements in or relating to hydraulic tappets |
| US4258671A (en) * | 1978-03-13 | 1981-03-31 | Toyota Jidosha Kogyo Kabushiki Kaisha | Variable valve lift mechanism used in an internal combustion engine |
| JPS54155309A (en) * | 1978-05-27 | 1979-12-07 | Nissan Motor Co Ltd | Valve moving system for internal combustion engine |
| JPS59147806A (en) * | 1983-02-10 | 1984-08-24 | Isuzu Motors Ltd | Valve opening and closing control device in internal-combustion engine |
| EP0323591A2 (en) * | 1987-12-17 | 1989-07-12 | Klöckner-Humboldt-Deutz Aktiengesellschaft | Double-point timing device |
| CN101479445A (en) * | 2006-06-30 | 2009-07-08 | 瓦特西拉芬兰有限公司 | Control arrangement for a gas exchange valve in a piston engine and method of controlling a gas exchange valve in a piston engine |
| CN201588701U (en) * | 2009-12-11 | 2010-09-22 | 吴爽 | Stepless variable valve lifting mechanism |
| CN104564206A (en) * | 2015-01-23 | 2015-04-29 | 吉林大学 | Cam-driven hydraulic fully variably valve mechanism of internal combustion engine |
| CN206071662U (en) * | 2016-09-22 | 2017-04-05 | 西华大学 | A kind of changeable air valve tappet |
Also Published As
| Publication number | Publication date |
|---|---|
| CN106285811A (en) | 2017-01-04 |
| CN106285811B (en) | 2018-10-19 |
| CA3034548C (en) | 2019-06-04 |
| CA3034548A1 (en) | 2018-03-29 |
| GB2568621B (en) | 2019-10-09 |
| GB201903051D0 (en) | 2019-04-24 |
| WO2018053892A1 (en) | 2018-03-29 |
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