Fully variable electro-hydraulic valve system

Abstract

The fully-variable electro-hydraulic valve system comprises a cam shaft, a valve assembly, a hydraulic cylinder and a buffering and pressure stabilizing device, the buffering and pressure stabilizing device comprises a buffering cavity, one end of the buffering cavity communicates with an engine oil way of an engine through a one-way valve, and the other end of the buffering cavity is provided with a buffering plunger, a buffering spring and / or an overflow oil way; oil inlet and outlet holes are formed in the cavity wall of the buffer cavity, electromagnetic switch valves of cylinders of the engine are connected with the oil inlet and outlet holes through hydraulic oil branches of the cylinders, and all the cylinders of the engine share one set of buffer pressure stabilizing device; when the full-variable electro-hydraulic valve system works, pressure fluctuation of hydraulic oil in an engine oil way cannot be caused, oil pressure of the engine oil way is stable, pressure fluctuation of the hydraulic oil in the buffer cavity is within a certain range, and normal work of all cylinder variable valve systems and normal operation of an engine are guaranteed.

Description

Technical Field

[0001] This invention relates to the field of engine valve mechanism technology, and in particular to a fully variable electro-hydraulic valve system that controls valve movement through a combination of solenoid valves and camshaft. Background Technology

[0002] Fully Variable Valve System (FVVS) enables continuous variation of valve maximum lift, valve opening duration angle, and valve timing, which is of great significance for energy saving and emission reduction in engines. FVVS technology has become one of the important development directions of new internal combustion engine technologies.

[0003] Chinese utility model patent CN209053652U discloses a fully variable electro-hydraulic valve mechanism that controls valve movement through a combination of a camshaft and a solenoid valve, offering both fast response and convenient control. Chinese invention patent application number 202410429291.X also relates to a fully variable electro-hydraulic valve system. Both patents utilize solenoid valve control. When the solenoid valve disconnects the oil circuit, the cam drives the plunger, which in turn pushes the piston through the hydraulic oil in the hydraulic chamber, opening the valve. When the solenoid valve connects the oil circuit, the hydraulic oil in the hydraulic chamber first flows into the engine oil circuit, and the piston moves towards the closing direction under the force of the valve spring. After a certain point (e.g., the cam rotates, causing the plunger to descend to its maximum stroke position and the valve closes, at which point the piston stops moving upward), the hydraulic oil in the engine oil circuit flows back into the hydraulic chamber through the solenoid valve... This process repeats. Because the variable valve system repeatedly moves hydraulic oil in and out of the engine oil circuit, it causes pressure fluctuations in the hydraulic oil, negatively impacting the lubrication of bearings, connecting rod bearings, etc. Summary of the Invention

[0004] In view of this, the technical problem to be solved by the present invention is to provide a fully variable electro-hydraulic valve system to avoid hydraulic oil pressure fluctuations in the engine oil circuit and ensure stable oil pressure in the engine oil circuit.

[0005] To solve the above-mentioned technical problems, the technical solution of the present invention is: a fully variable electro-hydraulic valve system, comprising: a camshaft and valve assembly, a hydraulic cylinder, and a buffer pressure stabilizing device; the hydraulic cylinder includes a sliding sleeve, a plunger, a piston, and a return spring; the sliding sleeve is fixed relative to the engine; the plunger and the piston are respectively in sliding sealing cooperation with the sliding sleeve; the plunger is controlled by the cam surface of the camshaft; the piston abuts against the valve assembly; within the sliding sleeve, the space between the plunger and the piston forms a sealed hydraulic chamber; the return spring is clamped between the plunger and the piston; the sliding sleeve has an oil passage. The oil passage is connected to an electromagnetic switch valve; the buffer pressure stabilizing device includes a buffer chamber, one end of which is provided with an oil inlet, which is connected to the engine oil circuit through a one-way valve; the other end of the buffer chamber is provided with a buffer plunger and a buffer spring abutting against the buffer plunger; the wall of the buffer chamber is provided with inlet and outlet oil holes for hydraulic oil to flow into or out of the buffer chamber, and the number of inlet and outlet oil holes is consistent with the number of engine cylinders; the electromagnetic switch valve of each cylinder of the engine is connected to each of the inlet and outlet oil holes through the hydraulic oil branch of each cylinder, and all cylinders of the engine share one set of the buffer pressure stabilizing device.

[0006] Furthermore, the buffer chamber is provided with an overflow hole in its wall. The overflow hole is connected to the oil pan of the engine through an overflow oil passage. When the hydraulic oil pressure in the buffer chamber is less than a set value, the buffer plunger closes the overflow hole; when the hydraulic oil pressure in the buffer chamber is greater than the set value, the overflow hole opens.

[0007] Furthermore, an overflow valve is provided in the overflow oil circuit.

[0008] To solve the above-mentioned technical problems, the technical solution of the present invention can also be: a fully variable electro-hydraulic valve system, comprising: a camshaft and valve assembly, a hydraulic cylinder, and a buffer pressure stabilizing device; the hydraulic cylinder includes a sliding sleeve, a plunger, a piston, and a return spring; the sliding sleeve is fixed relative to the engine; the plunger and the piston are respectively in sliding sealing cooperation with the sliding sleeve; the plunger is controlled by the cam surface of the camshaft; the piston abuts against the valve assembly; within the sliding sleeve, the space between the plunger and the piston forms a sealed hydraulic chamber; the return spring is clamped between the plunger and the piston; the sliding sleeve has an oil passage hole, and the oil passage hole is connected to... The electromagnetic switching valve; the buffer pressure stabilizing device includes a buffer chamber, one end of which is provided with an oil inlet, which is connected to the engine oil circuit through a one-way valve, and the other end of which is provided with an overflow hole, which is connected to the engine oil pan through an overflow oil circuit, in which an overflow valve is provided; the wall of the buffer chamber is provided with inlet and outlet holes for hydraulic oil to flow into or out of the buffer chamber, and the number of inlet and outlet holes is consistent with the number of engine cylinders; the electromagnetic switching valve of each cylinder of the engine is connected to each of the inlet and outlet holes through the hydraulic oil branch of each cylinder, and all cylinders of the engine share one set of the buffer pressure stabilizing device.

[0009] After adopting the above technical solution, the beneficial effects of the present invention are as follows:

[0010] Because the fully variable electro-hydraulic valve system of the present invention includes a camshaft, valve assembly, hydraulic cylinder, and a buffer pressure stabilizing device, the buffer pressure stabilizing device includes a buffer chamber. One end of the buffer chamber is connected to the engine oil circuit through a one-way valve, and the other end of the buffer chamber is provided with a buffer plunger, a buffer spring, and / or an overflow oil circuit. The wall of the buffer chamber is provided with inlet and outlet oil holes. The solenoid valves of each cylinder of the engine are connected to the inlet and outlet oil holes through the hydraulic oil branches of each cylinder. All cylinders of the engine share a set of buffer pressure stabilizing devices. During operation, due to the action of the one-way valve, the engine oil in the engine oil circuit can only flow into the buffer chamber in one direction, while the hydraulic oil in the buffer chamber cannot flow back to the engine oil circuit, thus preventing engine damage. The hydraulic oil pressure fluctuations in the oil circuit ensure the stability of the engine oil pressure, avoiding adverse effects on the lubrication of bearings, connecting rod bearings, etc., and facilitating normal engine operation. The hydraulic oil in each cylinder's hydraulic chamber flows into or out of the buffer chamber through the hydraulic oil branch of each cylinder, causing pressure fluctuations in the buffer chamber. When the pressure in the buffer chamber increases (hydraulic oil from the branch flows into the buffer chamber), the hydraulic oil pushes the buffer plunger to move and / or releases pressure through the overflow oil circuit, reducing the pressure. When the pressure in the buffer chamber decreases, the engine oil in the oil circuit flows into the buffer chamber through the one-way valve, keeping the pressure fluctuations in the buffer chamber within a certain range and ensuring the normal operation of the variable valve system in each cylinder. Attached Figure Description

[0011] Figure 1This is a schematic diagram of the fully variable electro-hydraulic valve system of Embodiment 1 of the present invention;

[0012] Figure 2 This is a schematic diagram of the fully variable electro-hydraulic valve system of Embodiment 2 of the present invention;

[0013] Figure 3 This is a schematic diagram of the fully variable electro-hydraulic valve system of Embodiment 3 of the present invention;

[0014] Figure 4 This is a schematic diagram of the fully variable electro-hydraulic valve system of Embodiment 4 of the present invention (overflow hole closed);

[0015] Figure 5 This is a schematic diagram of the fully variable electro-hydraulic valve system of Embodiment 4 of the present invention (overflow hole open state);

[0016] In the diagram: 101, Camshaft; 102, Piston; 103, Sliding Sleeve; 104, Return Spring; 105, Piston; 106, Valve Assembly; 107, Solenoid Valve; Q, Hydraulic Chamber;

[0017] 201, Buffer chamber; 201A, Oil inlet; 201B, Oil inlet / outlet; 201C, Overflow port; 202, Check valve; 203, Buffer plunger; 204, Buffer spring; 205, Overflow valve; L1, Hydraulic oil branch of cylinder 1;

[0018] L2, hydraulic oil branch for cylinder 2; L3, hydraulic oil branch for cylinder 3; L4, hydraulic oil branch for cylinder 4; L5, hydraulic oil branch for cylinder 5; L6, hydraulic oil branch for cylinder 6. Detailed Implementation

[0019] The present invention will now be further described in a non-limiting manner with reference to the accompanying drawings and embodiments.

[0020] Example 1

[0021] like Figure 1 As shown, the fully variable electro-hydraulic valve system of this invention includes: a camshaft 101, a valve assembly 106, a hydraulic cylinder, and a buffer pressure stabilizing device.

[0022] The hydraulic cylinder includes a sliding sleeve 103, a plunger 102, a piston 105, and a return spring 104. The sliding sleeve 103 is fixed relative to the engine. The plunger 102 and the piston 105 are respectively slidably sealed with the sliding sleeve 103. The plunger 102 is controlled by the cam surface of the camshaft 101. The piston 105 abuts against the valve assembly 106. In the sliding sleeve 103, the space between the plunger 102 and the piston 105 forms a sealed hydraulic chamber Q. The return spring 104 is clamped between the plunger 102 and the piston 105. The sliding sleeve 103 has an oil passage hole, which is connected to the solenoid valve 107.

[0023] The buffer pressure stabilizing device includes a buffer chamber 201. An oil inlet 201A is provided at one end of the buffer chamber 201. The oil inlet 201A is connected to the engine oil circuit through a one-way valve 202. The other end of the buffer chamber 201 is an open end. A buffer plunger 203 and a buffer spring 204 are provided at the open end. One end of the buffer spring 204 abuts against the buffer plunger 203, and the other end of the buffer spring 204 abuts against or is connected to the engine. The cavity wall of the buffer chamber 201 is provided with oil inlet and outlet holes 201B for hydraulic oil to flow into or out of the buffer chamber 201. The number of oil inlet and outlet holes 201B is the same as the number of engine cylinders.

[0024] The electromagnetic switching valve 107 of each cylinder of the engine is connected to each inlet and outlet oil port 201B through the hydraulic oil branch of each cylinder, and all cylinders of the engine share the same set of buffer pressure stabilizing device.

[0025] The diagram illustrates a six-cylinder engine as an example. Specifically, the solenoid valve 107 of cylinder 1 is connected to its corresponding inlet / outlet port 201B via the cylinder 1 hydraulic oil branch L1; the solenoid valve of cylinder 2 is connected to its corresponding inlet / outlet port via the cylinder 2 hydraulic oil branch L2; the solenoid valve of cylinder 3 is connected to its corresponding inlet / outlet port via the cylinder 3 hydraulic oil branch L3; the solenoid valve of cylinder 4 is connected to its corresponding inlet / outlet port via the cylinder 4 hydraulic oil branch L4; the solenoid valve of cylinder 5 is connected to its corresponding inlet / outlet port via the cylinder 5 hydraulic oil branch L5; and the solenoid valve of cylinder 6 is connected to its corresponding inlet / outlet port via the cylinder 6 hydraulic oil branch L6.

[0026] Obviously, the attached diagram is only illustrative and is not limited to a six-cylinder engine; the number of cylinders in an engine can be increased or decreased.

[0027] In the fully variable electro-hydraulic valve system of this invention, during operation, due to the function of the one-way valve 202, the engine oil in the engine oil circuit can only flow into the buffer chamber 201 in one direction, while the hydraulic oil in the buffer chamber 201 cannot flow back to the engine oil circuit. This prevents fluctuations in the hydraulic oil pressure of the engine oil circuit, ensuring the stability of the engine oil pressure and avoiding adverse effects on the lubrication of bearings, connecting rod bearings, etc., thus facilitating the normal operation of the engine.

[0028] Hydraulic oil in the hydraulic chamber Q of each cylinder flows into or out of the buffer chamber 201 through the hydraulic oil branch of each cylinder, causing pressure fluctuations in the hydraulic oil in the buffer chamber 201. When the pressure in the buffer chamber 201 increases (hydraulic oil from the branch flows into the buffer chamber), the hydraulic oil pushes the buffer plunger 203 to move to the right as shown in the figure, reducing the pressure. When the pressure in the buffer chamber 201 decreases, the buffer plunger 203 moves to the left under the action of the buffer spring 204. At the same time, the engine oil in the engine oil circuit flows into the buffer chamber 201 through the one-way valve 202. Through the combined action of the buffer plunger 203 and the buffer spring 204, the pressure fluctuations of the hydraulic oil in the buffer chamber 201 are kept within a certain range, ensuring the normal operation of the variable valve system of each cylinder.

[0029] Example 2

[0030] like Figure 2 As shown, the structure of this embodiment is basically the same as that of embodiment 1, except that the other end of the buffer chamber 201 is not provided with a buffer plunger and a buffer spring. The other end of the buffer chamber 201 is closed, and an overflow hole 201C is provided on the cavity wall at or near the closed end. The overflow hole 201C is connected to the oil pan of the engine through an overflow oil passage, and an overflow valve 205 is provided in the overflow oil passage.

[0031] Furthermore, the opening pressure of the relief valve 205 is set to be greater than the pressure of the engine hydraulic oil and much less than the pressure generated by the valve spring thrust on the hydraulic oil in the hydraulic chamber Q. For example, if the engine hydraulic oil pressure is 0.2-0.6 MPa and the pressure generated by the valve spring thrust on the hydraulic oil in the hydraulic chamber Q is greater than 2 MPa, the opening pressure of the relief valve 205 can be set to 0.8 MPa.

[0032] When all cylinders’ solenoid valve 107 is closed, the relief valve 205 is closed because the opening pressure of the relief valve 205 is greater than the engine hydraulic oil pressure.

[0033] When the solenoid valve 107 is opened and the hydraulic oil in the hydraulic chamber Q flows into the buffer chamber 201, the check valve 202 closes and the relief valve 205 opens, draining the hydraulic oil flowing out of the hydraulic chamber Q. When the solenoid valve 107 is opened and the hydraulic oil in the buffer chamber 201 flows into the hydraulic chamber Q, the relief valve 205 closes and the check valve 202 opens, allowing the engine oil circuit oil to flow into the buffer chamber 201 through the check valve 202, keeping the pressure fluctuation of the hydraulic oil in the buffer chamber 201 within a certain range, thus ensuring the normal operation of the variable valve system of each cylinder.

[0034] Example 3

[0035] like Figure 3As shown, this embodiment combines Embodiment 1 and Embodiment 2. The other end of the buffer chamber 201 is provided with a buffer plunger 203 and a buffer spring 204 that abuts against the buffer plunger 203. Furthermore, the cavity wall at the other end of the buffer chamber 201 is provided with an overflow hole 201C. The overflow hole 201C is connected to the oil pan of the engine through an overflow oil passage. An overflow valve 205 is provided in the overflow oil passage.

[0036] For example, if the engine hydraulic oil pressure is 0.2-0.6 MPa, and the pressure generated by the valve spring thrust on the hydraulic oil in the hydraulic chamber Q is greater than 2 MPa, the opening pressure of the relief valve 205 is set to 0.8 MPa. When the pressure in the buffer chamber 201 is between 0.2-0.8 MPa, the pressure fluctuation is stabilized by the buffer plunger 203. When the pressure in the buffer chamber 201 is greater than 0.8 MPa, the pressure greater than 0.8 MPa is released by the relief valve 205 to ensure the stability of the pressure in the buffer chamber 201.

[0037] Example 4

[0038] like Figure 4 As shown, in this embodiment, a buffer plunger 203 and a buffer spring 204 abutting against the buffer plunger 203 are provided at the other end of the buffer chamber 201. The cavity wall of the buffer chamber 201 is provided with an overflow hole 201C, which is connected to the oil pan of the engine through an overflow oil passage. No overflow valve is provided in the overflow oil passage, which is a simplification based on embodiment 3. The structure is simple and the cost is low. When the hydraulic oil pressure in the buffer chamber 201 is less than a set value (for example, set to 0.8MPa), the buffer plunger 203 closes the overflow hole 201C.

[0039] like Figure 5 As shown, when the hydraulic oil pressure in the buffer chamber 201 is greater than the set value, the overflow hole 201C opens to release the high-pressure hydraulic oil and ensure the stability of the pressure in the buffer chamber 201.

[0040] The above description is an example of a preferred embodiment of the present invention. All parts not described in detail are known technologies in the art. The scope of protection of the present invention is determined by the content of the claims. Any equivalent transformations based on the technical teachings of the present invention are within the scope of protection of the present invention.

Claims

1. A fully variable electro-hydraulic valve system, including: Camshaft and valve assembly; A hydraulic cylinder includes a sliding sleeve, a plunger, a piston, and a return spring. The sliding sleeve is fixed relative to the engine. The plunger and the piston are respectively in sliding sealing cooperation with the sliding sleeve. The plunger is controlled by the cam surface of the camshaft. The piston abuts against the valve assembly. A sealed hydraulic chamber is formed in the space between the plunger and the piston within the sliding sleeve. The return spring is clamped between the plunger and the piston. The sliding sleeve has an oil passage connected to an electromagnetic switching valve. The fully variable electro-hydraulic valve system further includes: A buffer pressure stabilizing device includes a buffer chamber, one end of which is provided with an oil inlet, which is connected to the engine oil circuit through a one-way valve. The other end of the buffer chamber is provided with a buffer plunger and a buffer spring that abuts against the buffer plunger. The wall of the buffer chamber is provided with inlet and outlet oil holes for hydraulic oil to flow into or out of the buffer chamber. The number of inlet and outlet oil holes is consistent with the number of engine cylinders. The electromagnetic switch valves of each cylinder of the engine are connected to the inlet and outlet ports through the hydraulic oil branch of each cylinder, and all cylinders of the engine share a set of buffer pressure stabilizing devices.

2. The fully variable electro-hydraulic valve system as described in claim 1, characterized in that, The buffer chamber is provided with an overflow hole in its wall. The overflow hole is connected to the oil pan of the engine through an overflow oil passage. When the hydraulic oil pressure in the buffer chamber is less than a set value, the buffer plunger closes the overflow hole; when the hydraulic oil pressure in the buffer chamber is greater than the set value, the overflow hole opens.

3. The fully variable electro-hydraulic valve system as described in claim 2, characterized in that, An overflow valve is installed in the overflow oil circuit.

4. Fully variable electro-hydraulic valve system, including: Camshaft and valve assembly; A hydraulic cylinder includes a sliding sleeve, a plunger, a piston, and a return spring. The sliding sleeve is fixed relative to the engine. The plunger and the piston are respectively in sliding sealing cooperation with the sliding sleeve. The plunger is controlled by the cam surface of the camshaft. The piston abuts against the valve assembly. A sealed hydraulic chamber is formed in the space between the plunger and the piston within the sliding sleeve. The return spring is clamped between the plunger and the piston. The sliding sleeve has an oil passage connected to an electromagnetic switching valve. The fully variable electro-hydraulic valve system further includes: A buffer pressure stabilizing device includes a buffer chamber. One end of the buffer chamber has an oil inlet, which is connected to the engine oil circuit via a one-way valve. The other end of the buffer chamber has an overflow hole, which is connected to the engine oil pan via an overflow oil circuit. An overflow valve is installed in the overflow oil circuit. The wall of the buffer chamber has inlet and outlet holes for hydraulic oil to flow into or out of the buffer chamber. The number of inlet and outlet holes is the same as the number of engine cylinders. The electromagnetic switch valves of each cylinder of the engine are connected to the inlet and outlet ports through the hydraulic oil branch of each cylinder, and all cylinders of the engine share a set of buffer pressure stabilizing devices.

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