Fully variable electro-hydraulic valve system

Abstract

The utility model discloses a full-variable electro-hydraulic valve system which 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 is communicated 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] The utility model relates to the technical field of engine valve mechanisms, in particular to a fully variable electro-hydraulic valve system which controls valve movement through a solenoid valve and a camshaft. Background Art

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

[0003] Chinese utility model patent CN209053652U discloses a fully variable electro-hydraulic valve mechanism, which controls the valve movement through the camshaft and the solenoid valve, which not only has a fast response speed but also is easy to control. The Chinese invention patent application with application number 202410429291.X also involves a fully variable electro-hydraulic valve system. Both patent technologies are controlled by solenoid valves. When the solenoid valve disconnects the oil circuit, the cam drives the plunger to move and pushes the piston to move through the hydraulic oil in the hydraulic chamber to open the valve; when the solenoid valve connects the oil circuit, the hydraulic oil in the hydraulic chamber first flows out to the engine oil circuit, and the piston moves in the closing direction under the action of the valve spring force. At a certain moment (for example, the cam rotates to drive the plunger down to the maximum stroke position and the valve closing piston no longer moves up), the hydraulic oil in the engine oil circuit flows to the hydraulic chamber through the solenoid valve... Repeatedly, due to the repeated inflow and outflow of hydraulic oil into the engine oil circuit during the operation of the variable valve system, the hydraulic oil pressure in the engine oil circuit fluctuates, resulting in adverse effects on 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 utility model 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] In order to solve the above technical problems, the technical solution of the utility model is: a fully variable electro-hydraulic valve system, including: a camshaft and a valve assembly, a hydraulic cylinder, and a buffer pressure stabilizing device; the hydraulic cylinder includes a sleeve, a plunger, a piston and a return spring, the sleeve is fixed relative to the engine, the plunger and the piston are respectively slidably sealed with the sleeve, the plunger is controlled by the cam surface of the camshaft, the piston is pressed against the valve assembly, and the space between the plunger and the piston in the sleeve forms a sealed hydraulic chamber, and the return spring is clamped between the plunger and the piston; the sleeve is provided with a through hole An oil hole, the oil hole is connected to an electromagnetic switch valve; the buffer pressure stabilizing device includes a buffer chamber, one end of the buffer chamber is provided with an oil inlet hole, the oil inlet hole 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 against the buffer plunger, the cavity 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 the 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 each of the inlet and outlet oil holes through the hydraulic oil branches of each cylinder, and all cylinders of the engine share a set of the buffer pressure stabilizing device.

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

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

[0008] In order to solve the above technical problems, the technical solution of the utility model can also be: a fully variable electro-hydraulic valve system, including: a camshaft and a valve assembly, a hydraulic cylinder, and a buffer pressure stabilizing device; the hydraulic cylinder includes a sleeve, a plunger, a piston and a return spring, the sleeve is fixed relative to the engine, the plunger and the piston are respectively slidably sealed with the sleeve, the plunger is controlled by the cam surface of the camshaft, the piston is pressed against the valve assembly, and the space between the plunger and the piston in the sleeve forms a sealed hydraulic chamber, and the return spring is clamped between the plunger and the piston; the sleeve is provided with an oil hole, and the oil hole is connected to the There is an electromagnetic switch valve; the buffer pressure stabilizing device includes a buffer chamber, one end of the buffer chamber is provided with an oil inlet hole, the oil inlet hole is connected with the engine oil circuit through a one-way valve, the other end of the buffer chamber is provided with an overflow hole, the overflow hole is connected with the oil pan of the engine through an overflow oil circuit, and an overflow valve is provided in the overflow oil circuit; the cavity 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 the inlet and outlet holes is consistent with the number of engine cylinders; the electromagnetic switch valves of each cylinder of the engine are connected with each inlet and outlet hole through the hydraulic oil branch of each cylinder, and all cylinders of the engine share a set of the buffer pressure stabilizing device.

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

[0010] Since the fully variable electro-hydraulic valve system of the utility model includes a camshaft, a valve assembly, a 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 cavity wall of the buffer chamber is provided with oil inlet and outlet holes, and the electromagnetic switch valves of each cylinder of the engine are connected to each oil inlet and outlet hole through each cylinder hydraulic oil branch, and all cylinders of the engine share a set of buffer pressure-stabilizing devices; when working, due to the action of the one-way valve, the oil in the engine oil circuit can only flow into the buffer chamber in one direction, and the hydraulic oil in the buffer chamber cannot flow back to the engine oil circuit, thereby not causing the engine to The hydraulic oil pressure fluctuation in the engine oil circuit ensures the stability of the oil pressure in the engine oil circuit, avoids adverse effects on the lubrication of bearings, connecting rod bearings, etc., and is conducive to the normal operation of the engine; the hydraulic oil in the hydraulic chamber of each cylinder flows into or out of the buffer chamber through the hydraulic oil branches of each cylinder, causing fluctuations in the hydraulic oil pressure in the buffer chamber. When the pressure in the buffer chamber increases (the hydraulic oil in 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 to reduce the pressure; when the pressure in the buffer chamber decreases, the engine oil in the engine oil circuit flows into the buffer chamber through the one-way valve, so that the pressure fluctuation of the hydraulic oil in the buffer chamber is within a certain range, thereby ensuring the normal operation of the variable valve system of each cylinder. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 This is a schematic diagram of the structure of a fully variable electro-hydraulic valve system according to Embodiment 1 of the present utility model;

[0012] Figure 2 This is a schematic diagram of the structure of a fully variable electro-hydraulic valve system according to Embodiment 2 of the present utility model;

[0013] Figure 3 Schematic diagram of the structure of a fully variable electro-hydraulic valve system according to Embodiment 3 of the present utility model;

[0014] Figure 4 1 is a schematic diagram of the structure of a fully variable electro-hydraulic valve system according to Embodiment 4 of the present utility model (in a state where the overflow hole is closed);

[0015] Figure 5 Schematic diagram of the structure of the fully variable electro-hydraulic valve system of Embodiment 4 of the present utility model (with the overflow hole opened);

[0016] In the figure: 101, camshaft; 102, plunger; 103, sleeve; 104, return spring; 105, piston; 106, valve assembly; 107, solenoid switch valve; Q, hydraulic chamber;

[0017] 201, buffer chamber; 201A, oil inlet hole; 201B, oil inlet and outlet holes; 201C, overflow hole; 202, one-way valve; 203, buffer plunger; 204, buffer spring; 205, overflow valve; L1, 1 cylinder hydraulic oil branch;

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

[0019] The present invention is further described in a non-limiting manner below in conjunction with the accompanying drawings and embodiments.

[0020] Example 1

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

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

[0023] Among them, the buffering and pressure-stabilizing device includes a buffer chamber 201, at one end of which an oil inlet hole 201A is arranged, and the oil inlet hole 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, and the open end is provided with a buffer plunger 203 and a buffer spring 204. 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, and the number of the oil inlet and outlet holes 201B is consistent with the number of engine cylinders.

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

[0025] In the figure, a six-cylinder engine is used as an example, that is: the solenoid switch valve 107 of the engine cylinder 1 is connected to a corresponding oil inlet and outlet hole 201B through the cylinder 1 hydraulic oil branch L1, the solenoid switch valve of the 2nd cylinder is connected to a corresponding oil inlet and outlet hole through the cylinder 2 hydraulic oil branch L2, the solenoid switch valve of the 3rd cylinder is connected to a corresponding oil inlet and outlet hole through the cylinder 3 hydraulic oil branch L3, the solenoid switch valve of the 4th cylinder is connected to a corresponding oil inlet and outlet hole through the cylinder 4 hydraulic oil branch L4, the solenoid switch valve of the 5th cylinder is connected to a corresponding oil inlet and outlet hole through the cylinder 5 hydraulic oil branch L5, and the solenoid switch valve of the 6th cylinder is connected to a corresponding oil inlet and outlet hole through the cylinder 6 hydraulic oil branch L6.

[0026] Obviously, the drawings are only schematic and are not limited to six-cylinder engines, and the number of engine cylinders may be increased or decreased.

[0027] In the fully variable electro-hydraulic valve system of the embodiment of the utility model, during operation, due to the action of the one-way valve 202, the oil in the engine oil circuit can only flow into the buffer chamber 201 in one direction, and the hydraulic oil in the buffer chamber 201 cannot flow back to the engine oil circuit, thereby not causing fluctuations in the hydraulic oil pressure of the engine oil circuit, ensuring the stability of the oil pressure of the engine oil circuit, and further avoiding adverse effects on the lubrication of bearings, connecting rod bearings, etc., which is beneficial to the normal operation of the engine.

[0028] The hydraulic oil in the hydraulic chamber Q of each cylinder flows into or out of the buffer chamber 201 through the hydraulic oil branches of each cylinder, causing fluctuations in the hydraulic oil pressure in the buffer chamber 201. When the pressure in the buffer chamber 201 increases (the hydraulic oil of the branch flows into the buffer chamber), the hydraulic oil pushes the buffer plunger 203 to move rightward as shown in the figure to reduce the pressure. When the pressure in the buffer chamber 201 decreases, the buffer plunger 203 moves leftward under the action of the buffer spring 204, and the oil in the engine oil circuit flows into the buffer chamber 201 through the one-way valve 202. Through the joint action of the buffer plunger 203 and the buffer spring 204, the pressure fluctuation of the hydraulic oil in the buffer chamber 201 is within a certain range, thereby 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 no buffer plunger and buffer spring are provided at the other end of the buffer cavity 201. The other end of the buffer cavity 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 circuit, and an overflow valve 205 is provided in the overflow oil circuit.

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

[0032] When the electromagnetic switch valves 107 of all cylinders are 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 switch valve 107 is opened and the hydraulic oil in the hydraulic chamber Q flows into the buffer chamber 201, the one-way valve 202 is closed and the overflow valve 205 is opened to discharge the hydraulic oil flowing out of the hydraulic chamber Q; when the solenoid switch valve 107 is opened and the hydraulic oil in the buffer chamber 201 flows into the hydraulic chamber Q, the overflow valve 205 is closed and the one-way valve 202 is opened, and the oil in the engine oil circuit flows into the buffer chamber 201 through the one-way valve 202, so that the pressure fluctuation of the hydraulic oil in the buffer chamber 201 is within a certain range, thereby ensuring the normal operation of the variable valve system of each cylinder.

[0034] Example 3

[0035] like Figure 3 As shown, this embodiment is a combination of Embodiment 1 and Embodiment 2, and a buffer plunger 203 and a buffer spring 204 resting against the buffer plunger 203 are provided at the other end of the buffer chamber 201, and an overflow hole 201C is provided on the cavity wall at the other end of the buffer chamber 201, and the overflow hole 201C is connected to the oil pan of the engine through an overflow oil circuit, and an overflow valve 205 is provided in the overflow oil circuit.

[0036] For example, when the engine hydraulic oil pressure is 0.2-0.6MPa, the pressure exerted by the valve spring thrust on the hydraulic oil in the hydraulic chamber Q is greater than 2MPa, and the opening pressure of the relief valve 205 is set to 0.8MPa; when the pressure in the buffer chamber 201 is between 0.2-0.8MPa, the pressure fluctuation is stabilized by the buffer plunger 203; when the pressure in the buffer chamber 201 is greater than 0.8MPa, the pressure greater than 0.8MPa is unloaded 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 against the buffer plunger 203 are provided at the other end of the buffer chamber 201, and an overflow hole 201C is provided on the wall of the buffer chamber 201. The overflow hole 201C is connected to the oil pan of the engine through an overflow oil circuit, and no overflow valve is provided in the overflow oil circuit. This is a simplification based on Embodiment 3, with a simple structure and low cost. When the hydraulic oil pressure in the buffer chamber 201 is less than a set value (for example, set to 0.8 MPa), 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 discharge the high-pressure hydraulic oil to 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, and the parts not described in detail are all known technologies in the art. The protection scope of the present invention is based on the content of the claims, and any equivalent changes based on the technical inspiration of the present invention are within the protection scope of the present invention.

Claims

1. Fully variable electro-hydraulic valve system, including: camshafts and valve train assemblies; A hydraulic cylinder, the hydraulic cylinder comprises a sleeve, a plunger, a piston and a return spring, the sleeve is fixed relative to the engine, the plunger and the piston are respectively slidably sealed with the sleeve, the plunger is controlled by the cam surface of the camshaft, the piston abuts against the valve assembly, and in the 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 sleeve is provided with an oil hole, the oil hole is connected to an electromagnetic switch valve, and the fully variable electro-hydraulic valve system further comprises: A buffer pressure stabilizing device, the buffer pressure stabilizing device comprising a buffer chamber, one end of the buffer chamber is provided with an oil inlet hole, the oil inlet hole 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 leaning against the buffer plunger, the cavity 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 the 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 oil inlet and outlet holes through the hydraulic oil branch of each cylinder, and all cylinders of the engine share a set of the buffer pressure stabilizing device.

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

3. The fully variable electro-hydraulic valve system according to claim 2, characterized in that: An overflow valve is arranged in the overflow oil circuit.

4. Fully variable electro-hydraulic valve system, including: camshafts and valve train assemblies; A hydraulic cylinder, the hydraulic cylinder comprises a sleeve, a plunger, a piston and a return spring, the sleeve is fixed relative to the engine, the plunger and the piston are respectively slidably sealed with the sleeve, the plunger is controlled by the cam surface of the camshaft, the piston abuts against the valve assembly, and in the 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 sleeve is provided with an oil hole, the oil hole is connected to an electromagnetic switch valve, and the fully variable electro-hydraulic valve system further comprises: A buffering and pressure-stabilizing device, the buffering and pressure-stabilizing device comprising a buffering chamber, one end of the buffering chamber being provided with an oil inlet hole, the oil inlet hole being connected to the engine oil circuit through a one-way valve, the other end of the buffering chamber being provided with an overflow hole, the overflow hole being connected to the oil pan of the engine through an overflow oil circuit, the overflow oil circuit being provided with an overflow valve; the cavity wall of the buffering chamber being provided with inlet and outlet oil holes for hydraulic oil to flow into or out of the buffering chamber, the number of the inlet and outlet oil holes being consistent with the number of engine cylinders; The electromagnetic switch valve of each cylinder of the engine is connected to each of the oil inlet and outlet holes through the hydraulic oil branch of each cylinder, and all cylinders of the engine share a set of the buffer pressure stabilizing device.

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