Valve actuating mechanism and automobile
By combining a large-lift, large-wrap intake camshaft design with a three-position four-way oil control valve, intake valve control is optimized, solving the problem of low engine combustion efficiency, achieving improved combustion efficiency and reduced fuel consumption, while also reducing harmful gas emissions.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- SAIC GENERAL MOTORS
- Filing Date
- 2025-06-09
- Publication Date
- 2026-05-22
AI Technical Summary
Existing engines have low combustion efficiency and cannot effectively utilize the high pressure of exhaust gases after combustion, resulting in high fuel consumption.
It adopts a large lift and large wrap angle intake camshaft design, combined with small bearing caps with wing features and stamped rocker arms, to enhance the lubrication of valves and roller rocker arms, and realizes the position adjustment of intake phaser through three-position four-way oil control valve to optimize the opening and closing timing of intake valves.
It improves engine combustion efficiency, reduces fuel consumption, and reduces harmful gas emissions, meeting stricter environmental standards.
Smart Images
Figure CN224266488U_ABST
Abstract
Description
Technical Field
[0001] This application relates to the automotive field, and more specifically, to a valve train and an automobile having such a valve train. Background Technology
[0002] The primary function of the engine's valve train is to convert the rotational motion of the camshaft into the linear motion of the valves. According to the engine's working cycle and firing order, it opens and closes the intake and exhaust valves in each cylinder at set times, controlling the airflow into and out of the combustion chamber, and maintaining the combustion chamber's seal when necessary, thus achieving the engine's working cycle. A secondary function of the valve train is to drive the high-pressure fuel pump.
[0003] By extending the power stroke and shortening the compression stroke, the expansion ratio is made greater than the compression ratio, thereby improving thermal efficiency. Specifically, during the compression stroke, the piston moves from bottom dead center to top dead center, the intake and exhaust valves close, the volume of gas in the cylinder decreases and the pressure increases, reaching a compression state. During the power stroke, the piston moves from top dead center to bottom dead center, the intake and exhaust valves close, the volume of gas in the cylinder increases and the pressure decreases, ultimately performing work. By delaying the closing of the intake valve, some of the air-fuel mixture is expelled during the piston's compression stroke, reducing the intake volume and making the expansion ratio greater than the compression ratio. This allows for more effective utilization of the high pressure remaining in the exhaust gases after combustion, improving combustion efficiency and reducing fuel consumption. This is the Atkinson cycle, often used in hybrid engines. Summary of the Invention
[0004] The main technical problem this application aims to solve is how to improve the combustion efficiency of an engine.
[0005] To solve the above-mentioned technical problems, this application provides a valve train mechanism, which includes an intake camshaft, a roller rocker arm that drives a valve to move linearly, and an intake camshaft that includes an intake cam strip with a base circle radius of 16 mm and a maximum lift of 6-7 mm.
[0006] According to one aspect of this application, the valve train includes an intake phaser for adjusting the opening and closing of the intake valve.
[0007] According to one aspect of the valve train, the intake phaser is fastened to the intake camshaft via an oil control valve. The oil control valve has threads on its outer circumference and is a three-position four-way valve. The position of the intake phaser can be controlled by controlling the position of the valve core of the oil control valve.
[0008] According to one aspect of this application, the valve train includes a hydraulic tappet, and the roller rocker arm contacts the intake valve at one end and the hydraulic tappet at the other end.
[0009] According to one aspect of this application, the valve train includes a valve spring, the lower end face of which is mounted on a valve stem seal, and the upper end face of which contacts a valve spring seat, the valve spring causing the intake valve to tend to enter a closed state.
[0010] According to one aspect of this application, the valve train includes an exhaust camshaft, the exhaust camshaft includes an exhaust camshaft with a base circle radius of 16 mm and a maximum lift of 5-6 mm.
[0011] According to one aspect of this application, the valve train includes an exhaust sprocket for driving the exhaust camshaft, and the exhaust sprocket is fastened to the exhaust camshaft by an exhaust sprocket bolt.
[0012] According to one aspect of the valve train, the intake camshaft includes at least one pair of intake cam flaps, with a small bearing between the pair of intake cam flaps for mounting the intake camshaft, the small bearing having protrusions on both sides facing the intake cam flaps.
[0013] According to one aspect of the present application, an oil hole is provided at the ball socket of the roller rocker arm, and the oil hole points towards the outer ring of the roller.
[0014] On the other hand, this application provides an automobile that includes the valve train described in any of the preceding aspects. Attached Figure Description
[0015] The disclosure of this application is illustrated with reference to the accompanying drawings. It should be understood that the drawings are for illustrative purposes only and are not intended to limit the scope of protection of this application. Wherein:
[0016] Figure 1 A perspective view schematically illustrates a gas distribution mechanism according to one embodiment of this application;
[0017] Figure 2 The cross-sectional view schematically shows Figure 1 The gas distribution mechanism in the middle;
[0018] Figure 3 A stereoscopic diagram schematically shows the contents of Figure 1 The engine with a valve train;
[0019] Figure 4 Schematic representation Figure 1 The small cover of the valve train;
[0020] Figure 5 Schematic representation Figure 1The roller rocker arm of the valve train;
[0021] Figure 6 Schematic representation Figure 1 The contact surface of the intake phaser of the valve train facing the intake camshaft;
[0022] Figure 7 Schematic representation Figure 1 The oil passage of the oil control valve in the valve train. Detailed Implementation
[0023] The embodiments of this application will now be described in detail with reference to the accompanying drawings. Those skilled in the art will appreciate that these descriptions are merely descriptive and exemplary and should not be construed as limiting the scope of protection of this application.
[0024] Please see Figures 1 to 3 As shown, a valve train according to a specific embodiment of this application includes: an intake valve 1, an exhaust valve 2, a valve spring 3, a spring seat 4, a locking clip 5, a roller rocker arm 6, a hydraulic tappet 7, an intake camshaft 8, an exhaust camshaft 9, an intake phaser 10, an exhaust sprocket 11, an oil control valve 12, an exhaust sprocket bolt 13, a cylinder head 14, an intake valve oil seal 15, and an exhaust valve oil seal 16.
[0025] Intake valve 1 and exhaust valve 2 are mounted on the seat ring of cylinder head 14. Intake valve oil seal 15 and exhaust valve oil seal 16 are mounted on the oil seal mounting surface of cylinder head 14. The lower end face of valve spring 3 contacts the back of intake valve oil seal 15 and exhaust valve oil seal 16 respectively. The upper end face of valve spring 3 is engaged with the locking groove of intake valve 1 rod end and the locking groove of exhaust valve 2 rod end through spring seat 4 and locking clip 5 respectively to fix the phase position.
[0026] Hydraulic tappets 7 are installed on the right sides of intake valve 1 and exhaust valve 2, respectively, forming a 10° angle with each valve. Roller rocker arms 6 are installed on intake valve 1, exhaust valve 2, and hydraulic tappets 7. As intake camshaft 8 and exhaust camshaft 9 rotate, the camshaft lift of intake camshaft 8 and exhaust camshaft 9 changes, driving the roller rocker arms 6 to move, ultimately converting the rotational motion of intake camshaft 8 and exhaust camshaft 9 into linear motion of intake valve 1 and exhaust valve 2.
[0027] The intake valve 1 has an angle of 15.5° with the vertical direction, and the exhaust valve 2 has an angle of 21.5° with the vertical direction. The roller rocker arm 6 housing is stamped, and there is an oil injection hole at the ball joint of the roller rocker arm. Figure 5 As shown, the oil hole points to the outer ring of the rocker arm roller, and the valve end housing of the roller rocker arm has an open structure. This can shorten the oil passage for splash lubrication of the valve stem end face and enhance the wear resistance of the roller rocker arm.
[0028] The intake camshaft valve 19 has a base circle radius of 16mm and a maximum lift of 6-7mm. The exhaust camshaft valve 20 has a base circle radius of 16mm and a maximum lift of 5-6mm. Based on the relative positions of the intake valve 1, exhaust valve 2, roller rocker arm 6, and hydraulic tappet 7, the intake valve can achieve a maximum lift of 10-15mm, a 1mm wrap angle of 242°, early lock-up, and an IMOP between 450 and 560°. The exhaust valve can achieve a maximum lift of 9-14mm, a 1mm wrap angle of 184°, and an EMOP between 220 and 280°.
[0029] An exemplary operating process is as follows: First, the camshaft rotates, the tip of the camshaft vane contacts the roller end of the rocker arm, the rocker arm rotates around the hydraulic tappet fulcrum, and the other end presses down on the valve stem. Then, the valve opens against the spring force, the intake manifold opens, and when the camshaft vane tip passes its highest point, the valve spring pushes the valve to close, the rocker arm returns to its original position, and the hydraulic tappet dynamically adjusts to always maintain no clearance between the rocker arm and the cam / valve. The outer contour of the camshaft vane dynamically contacts the rolling bearing of the rocker arm, converting the rotational motion of the camshaft into the reciprocating motion of the rocker arm, ultimately pushing the valve to open / close. The profile of the camshaft vane precisely controls the valve opening timing, speed, lift, and duration. Lift refers to the maximum vertical displacement that pushes the valve away from the seat when the cam rotates. The lift curve is a function graph of the valve lift changing with the cam angle. The profile determines the lift; the outer contour profile of the camshaft vane (base circle - opening segment - apex - closing segment - base circle) directly maps to the lift curve. Higher lift increases intake / exhaust flow and improves high-speed power.
[0030] A larger valve lift and wrap angle result in a more "full" valve profile. This is amplified through the rocker arm transmission, resulting in a larger lift and wrap angle. The larger base circle radius of this size reduces contact stress. A larger wrap angle and lift mean a longer effective valve opening time and area, improving high-speed charging efficiency. Under some low loads, delayed intake valve closing reduces pumping losses.
[0031] The intake camshaft 8 and exhaust camshaft 9 are mounted on the cylinder head 14 via bearing caps, wherein the small bearing caps 17 have protrusions (wing features) on both sides, such as... Figure 4 As shown, without interference, the length of the two ends of the wing can be as close as possible to the width of the camshaft journal. The small bearing cover wing feature has a drainage function, which can easily make the lubricating oil at the journal splash onto the outer ring of the roller rocker arm 6. Under the action of centrifugal force, the lubricating oil on the outer ring of the roller rocker arm 6 can reach the valve stem end face, play a lubricating role, and enhance the wear resistance of the valve and the roller rocker arm.
[0032] The intake phaser 10 is positioned relative to the intake camshaft 8 via a locating pin, and the exhaust sprocket 11 is positioned relative to the exhaust camshaft 9 via a locating pin. The intake phaser 10 is secured to the intake camshaft 8 via an oil control valve 12. The exhaust sprocket 11 is secured to the exhaust camshaft 9 via an exhaust sprocket bolt 13. The contact surfaces between the intake phaser 10 and the exhaust sprocket 11 and the intake camshaft 8 and exhaust camshaft 9 are laser-etched surfaces, such as... Figure 6 As shown, the coefficient of friction is increased.
[0033] The intake camshaft 8 has five circumferentially distributed oblique oil holes at its first journal. Oil from the main oil passage in the cylinder head enters the oil control valve 12 through the oil passage inside the bearing cap 18 and the oblique oil holes at the first journal. The phase adjustment of the intake phaser 10 is achieved by changing the position of the valve core of the oil control valve. The oil inlet of the oil control valve has a one-way valve to ensure that the oil inside the valve does not return to the main oil passage in the cylinder head. The valve core of the oil control valve has two one-way valves, allowing for oil recycling when the intake phaser 10 adjusts its phase.
[0034] Oil control valve oil passage such as Figure 7 As shown, when the valve core is in its initial position of 0mm, oil at the inlet P enters the phaser's B chamber through port B. Simultaneously, oil in phaser A chamber returns to port B through the oil control valve (port A) and then re-enters phaser B chamber. Port T is the drain channel. When the valve core is in the 1.5mm position, the oil circuit between port P, ports A, and B of the oil control valve is disconnected, and the phase position remains unchanged. When the valve core is in the 3mm position, oil at the inlet P enters phaser A chamber through port A. Simultaneously, oil in phaser B chamber returns to port A through the oil control valve (port B) and then re-enters phaser A chamber.
[0035] The intake phaser is locked in the most advanced position, and can be adjusted 50-90° CA (crankshaft angle) in the retard direction via the oil control valve. At high speeds and high loads, it controls the intake valve to close later, ensuring sufficient intake and allowing fresh air or combustible mixture to continue flowing in at the end of the compression stroke, providing ample oxygen for combustion. At low speeds and low loads, by delaying the intake valve closing, some of the mixture is expelled during the piston compression stroke, reducing the intake volume and making the expansion ratio greater than the compression ratio. This allows for more efficient use of the high pressure remaining in the exhaust gases after combustion, improving combustion thermal efficiency, reducing fuel consumption, ensuring the most efficient use of fuel, optimizing the combustion process, and reducing emissions of harmful gases such as nitrogen oxides and carbon monoxide. This helps vehicles meet stricter environmental emission standards and improves overall environmental performance.
[0036] According to one embodiment of this application, the intake valve and exhaust valve are mounted on the cylinder head valve seat ring, the valve stem portion mates with the valve guide, and the valve stem end face contacts the roller rocker arm. The lower end face of the valve spring is mounted on the valve stem seal, the valve stem seal is mounted on the cylinder head, and the upper end face of the valve spring contacts the valve spring seat. The valve spring seat is installed by a locking clip engaging with the valve stem end locking groove. The valve spring provides spring force to keep the valve in the closed state. The hydraulic tappet is mounted on the cylinder head, and the cylinder head has an oil passage supplying oil to the hydraulic tappet. One end of the roller rocker arm is mounted on the valve, and the other end is mounted on the hydraulic tappet.
[0037] Furthermore, the roller rocker arm housing is stamped, and there is an oil injection hole at the ball socket of the roller rocker arm, with the oil hole pointing towards the outer ring of the rocker arm roller. The roller rocker arm valve end housing has an open structure, which shortens the oil path for splash lubrication of the valve stem end face and enhances the wear resistance of the rocker arm.
[0038] The intake camshaft is installed on the intake side of the cylinder head. It is a semi-assembled camshaft, with the intake cam and shaft cast as a single piece. The signal wheel is press-fitted (heat-fitted) onto the shaft. The intake camshaft has four pairs of leaf springs, with a journal in the middle of each pair, which mates with the cylinder head and bearing cap. The front end of the intake camshaft is the large end piece, and the rear end is the signal wheel.
[0039] Furthermore, the intake camshaft's camshaft profile is designed based on Atkinson cycle requirements, with a base circle radius of 16mm and a maximum lift of 6-7mm. The large end component of the intake camshaft includes a first journal with five oblique oil holes, a positioning groove at the front end, and two thrust surfaces. The first journal mates with the cylinder head bearing cap and has two features for fixing the camshaft bearing torque.
[0040] The exhaust camshaft is mounted on the exhaust side of the cylinder head. It is a semi-assembled camshaft, with the exhaust cam and shaft cast as a single piece. The high-pressure oil pump cam is press-fitted (heat-fitted) onto the shaft. The exhaust camshaft has four pairs of leaflets, with a journal in the middle of each pair, which mates with the cylinder head and bearing cap. The front end of the exhaust camshaft is the large end piece, and the rear end is the high-pressure oil pump leaflet.
[0041] Furthermore, the exhaust camshaft has a base circle radius of 16mm and a maximum lift of 5-6mm. The high-pressure oil pump has a base circle radius of 20.3mm and a maximum lift of 4-6mm. The large end component of the exhaust camshaft includes a first journal, with a positioning groove at the front end and two thrust surfaces. The first journal is fitted with the cylinder head bearing cap.
[0042] The cylinder head bearing cap has wing-like features, and there are oil holes on the cylinder head camshaft seat. The wing-like features of the bearing cap have a guiding effect on the oil, making it easy for the oil at the camshaft journal to reach the outer ring of the rocker arm bearing, thus enhancing the lubrication of the rocker arm.
[0043] The intake phaser is positioned with the intake camshaft via a locating pin, and the plane on the intake phaser that mates with the intake camshaft has laser-etched features. The maximum adjustment angle of the intake phaser in the lag direction is 50-90°CA.
[0044] The exhaust sprocket is positioned with the exhaust camshaft via a locating pin, and the plane on which the exhaust sprocket mates with the exhaust camshaft has laser-etched features.
[0045] The intake-side oil control valve securely connects the intake phaser to the intake camshaft. The oil control valve has a threaded outer circumference, functioning as a bolt. Furthermore, the oil control valve is a three-position four-way valve. Based on its internal oil passage design, the position of the phaser and the circulation of oil are controlled by adjusting the position of the valve core.
[0046] The exhaust side sprocket is fastened to the exhaust camshaft by bolts.
[0047] The valve train according to this embodiment adopts a large lift and large wrap angle design, which can effectively improve the combustion thermal efficiency of the hybrid engine. The use of small valve caps with wing-like features and stamped rocker arms with oil holes improves the robustness against wear on the valves and roller rocker arms. The three-position four-way oil control valve enables self-circulation of oil within the phaser during phase adjustment, reducing oil consumption.
[0048] This application also includes an automobile with a valve train according to any one or more of the foregoing embodiments, the technical features and effects of which correspond to the foregoing description, and therefore will not be repeated here.
Claims
1. A gas distribution mechanism, characterized in that, The valve train includes an intake camshaft that drives a roller rocker arm, which in turn drives the intake valve to move linearly. The intake camshaft includes an intake camshaft with a base circle radius of 16 mm and a maximum lift of 6-7 mm.
2. The gas distribution mechanism according to claim 1, characterized in that, The valve train includes an intake phaser, which is used to adjust the opening and closing of the intake valve.
3. The gas distribution mechanism according to claim 2, characterized in that, The intake phaser is fastened to the intake camshaft via an oil control valve. The oil control valve has threads on its outer circumference and is a three-position four-way valve. The position of the intake phaser can be controlled by controlling the position of the valve core of the oil control valve.
4. The gas distribution mechanism according to claim 1, characterized in that, The valve train includes a hydraulic tappet, and the roller rocker arm contacts the intake valve at one end and the hydraulic tappet at the other end.
5. The gas distribution mechanism according to claim 1, characterized in that, The valve train includes a valve spring, the lower end face of which is mounted on the valve stem seal, and the upper end face of which is in contact with the valve spring seat. The valve spring causes the intake valve to tend to enter the closed state.
6. The gas distribution mechanism according to claim 1, characterized in that, The valve train includes an exhaust camshaft, which includes an exhaust camshaft plate. The base circle radius of the exhaust camshaft plate is 16mm, and the maximum lift is 5-6mm.
7. The gas distribution mechanism according to claim 6, characterized in that, The valve train includes an exhaust sprocket, which drives the exhaust camshaft and is fastened to the exhaust camshaft by an exhaust sprocket bolt.
8. The gas distribution mechanism according to claim 1, characterized in that, The intake camshaft includes at least one pair of intake cam plates, and a small bearing is provided between the pair of intake cam plates for mounting the intake camshaft. The small bearing has protrusions on both sides facing the intake cam plates.
9. The gas distribution mechanism according to claim 1, characterized in that, An oil hole is provided at the ball socket of the roller rocker arm, and the oil hole points to the outer ring of the roller.
10. A car, characterized in that, It includes a gas distribution mechanism according to any one of claims 1 to 9.