CN108278137B

CN108278137B - Hydraulic variable valve driving device and system

Info

Publication number: CN108278137B
Application number: CN201810134123.2A
Authority: CN
Inventors: 李彦飞; 赵会军; 袁宝良; 李晓娟; 熊淦
Original assignee: FAW Group Corp
Current assignee: FAW Group Corp
Priority date: 2018-02-09
Filing date: 2018-02-09
Publication date: 2021-03-05
Anticipated expiration: 2038-02-09
Also published as: CN108278137A

Abstract

The invention relates to the technical field of internal combustion engines, and particularly discloses a hydraulic variable valve driving device, wherein the hydraulic variable valve driving device comprises: the high-pressure stabilizing source comprises a high-pressure stabilizing source, a low-pressure accumulating mechanism, a two-position four-way valve, a valve driver and a valve, wherein the output end of the high-pressure stabilizing source is connected with a port P of the two-position four-way valve, the low-pressure accumulating mechanism is connected with a port T of the two-position four-way valve, an upper oil inlet of the valve driver is connected with a port A of the two-position four-way valve, a lower oil inlet of the valve driver is connected with a port B of the two-position four-way valve, and. The invention also discloses a hydraulic variable valve driving system. The hydraulic variable valve driving device provided by the invention can flexibly control the opening and closing of the valve.

Description

Hydraulic variable valve driving device and system

Technical Field

The invention relates to the technical field of internal combustion engines, in particular to a hydraulic variable valve driving device and a hydraulic variable valve driving system comprising the same.

Background

In the prior art, in order to open and close the valves, there are several solutions, one of which is the philadelphite solution (US 8230830B 2), for example, as shown in fig. 1, in which a cam 10 drives a finger-shaped rocker arm 7, pushing a hydraulic piston 6 in compression, creating a high pressure in the piston chamber. When the electromagnetic valve 11 is opened, hydraulic oil enters the pressure accumulation cavity 12 and the hydraulic brake 4 through the electromagnetic valve, all oil paths are kept smooth at the moment, the pressure of the pressure accumulation cavity is kept low all the time due to the variable volume of the pressure accumulation cavity, and the air valve 2 is in a closed state; when the electromagnetic valve is closed, the high-low pressure cavity is disconnected, and the hydraulic oil in the hydraulic piston cavity is only communicated with the valve braking cavity. The oil cavity of the actuator is filled with engine oil, when the cam pushes the hydraulic piston to move downwards, the oil pressure is increased, and the hydraulic oil pushes the plunger of the hydraulic brake 4 to move downwards, so that the valve is pushed to open; when the valve is required to be seated, the electromagnetic valve is only required to be opened, the oil cavity of the hydraulic brake is communicated with the pressure accumulation cavity, the pressure in the high-pressure cavity is rapidly reduced, and the valve is seated under the action of the spring force. Therefore, the opening and closing time of the valve is flexibly changed by controlling the opening and closing of the electromagnetic valve. But the closing process is not controllable because the driving force for valve closing comes from the valve spring. The closing process of the valve is not controllable, so that the closing duration of the valve is prolonged at high speed. Since the valve spring force is constant at a fixed compression, the speed at which the valve closes is proportional to the spring force, i.e. the time required for the valve to close from maximum lift is fixed. This results in different rotational speeds, different crankshaft angles being required for closing the valve, and a much longer duration of valve closure at high speed. And because the hydraulic pressure for opening the valve is generated by driving the plunger through the cam, the variation range of the valve opening time is limited, the range of the valve with the lift is limited by the cam wrap angle, and the valve with the lift can only have the lift within the range of the cam wrap angle.

Alternatively, the cylinder may be a cylinder (chinese patent No. CN 1820123a), for example, as shown in fig. 2, a cam 200 drives a master piston 110, the master piston 110 is connected to a slave piston 120 through a passage 130, hydraulic oil is supplied to the system through a check valve 140, a control valve 150 is connected to an oil passage 130, and the slave piston 120 is connected to a valve 300. In operation, the cam drives the master piston 110 to move, creating a high pressure in the oil passage 130, driving the slave piston to move, and ultimately driving the valve to move. During the lift of the cam, when the valve is required to be closed, the control valve 150 is opened, the pressure in the oil passage 130 is reduced, the slave piston is returned, and the valve is closed. This realizes the variation of the valve lift by controlling the opening and closing of the control valve 150. The valve opening time is limited to the cam profile, the valve opening can be realized only in the cam rising section, and the valve opening can not be realized in the range of the wrap angles of other cams. The valve is closed through the action of a valve spring, the movement speed of the valve is uncontrollable when the valve is closed, and the closing duration of the valve at high speed is greatly prolonged.

In effectively controlling the valve seating velocity, there are various proposals, one of which is the philadelphite proposal (US 2003/0172890), and as shown in fig. 3, the control of the valve seating velocity is achieved by controlling the change in the hydraulic oil flow area when the valve is closed. The specific method is that the hydraulic oil in the high-pressure cavity C enters the plunger cavity through the one-way valve 32, the small hole 320 and the notch 42, and pushes the plunger 21 to move downwards, so as to push the valve to open. When the valve is closed, the valve 8 pushes the plunger 21 to move upwards under the action of the valve spring, and the plunger 21 presses hydraulic oil in the plunger cavity out of the high-pressure cavity C. With the reduction of the valve lift, the hydraulic oil in the plunger cavity flows out through the notch 42 and the small hole 320, the flow resistance is small, and the valve movement speed is high; then the slit 42 is closed and the hydraulic oil flows out only through the small hole 320, the flow resistance increases and the valve movement speed decreases. However, the motion speed of the valve closing is greatly influenced by the temperature, and the viscosity of hydraulic oil is increased at low temperature, so that the valve closing duration is prolonged. And the structure is complex, and the processing and manufacturing difficulty is high.

Another type is a homovalvular system (EP 1869294B 1), as shown in fig. 4, by the cooperation of the cylindrical hole 280 and the conical surface 225, when the valve is about to be seated, the flow area of the hydraulic oil is gradually reduced with the decrease of the valve lift, the flow resistance is increased, and the valve movement speed is reduced, thereby realizing the control of the valve seating speed. The valve block 280 with the cylindrical hole is pressed on the slide block 230 through the spring 260, and the conical valve core 225 is pressed on the valve block 280 through the spring 270. When the valve is closed, the valve pushes the slider 230, so that the cone of the valve core 225 gradually enters the cylindrical hole of the valve block 280, the slider 230 moves upwards along with the closing of the valve, the flow area of fluid passing through the inner hole of the valve block 280 is gradually reduced, the flow resistance is increased, the ascending speed of the valve block 280 is reduced, and the purpose of reducing the seating speed of the valve is achieved. However, due to the large influence of temperature, the viscosity of hydraulic oil is increased at low temperature, and the valve closing duration is prolonged. And when the valve is in a small lift, the flow area changes too quickly, which can make it difficult to effectively control the valve seating velocity.

Therefore, how to provide a driving device capable of flexibly controlling the opening and closing of the valve becomes a technical problem to be solved by those skilled in the art.

Disclosure of Invention

The present invention is directed to solve at least one of the problems of the prior art, and provides a hydraulic variable valve actuation device and a hydraulic variable valve actuation system including the same, so as to solve the problems of the prior art.

As a first aspect of the present invention, there is provided a hydraulic variable valve driving device, wherein the hydraulic variable valve driving device includes: a high-pressure stabilizing source, a low-pressure accumulating mechanism, a two-position four-way valve, a valve driver and a valve,

the output end of the high-pressure stabilizing source is connected with a port P of the two-position four-way valve, the low-pressure accumulating mechanism is connected with a port T of the two-position four-way valve, an upper oil inlet of the valve driver is connected with a port A of the two-position four-way valve, a lower oil inlet of the valve driver is connected with a port B of the two-position four-way valve, and a plunger of the valve driver is connected with the valve;

the communicating state of each port of the two-position four-way valve can control the high-pressure stabilizing source and the on-off of the upper pressure cavity and the lower pressure cavity of the valve driver, when hydraulic oil enters the upper pressure cavity of the valve driver, the valve driver can push the valve to be opened under the control of the high-pressure stabilizing source, when the hydraulic oil enters the lower pressure cavity of the valve driver, the valve driver can push the valve to be closed under the control of the high-pressure stabilizing source, and the low-pressure accumulation mechanism can temporarily store the hydraulic oil when the pressure state is switched by the high-pressure stabilizing source.

Preferably, when the port P of the two-position four-way valve is communicated with the port A and the port B is communicated with the port T, hydraulic oil can enter the upper pressure cavity of the valve driver, and when the port P of the two-position four-way valve is communicated with the port B and the port A is communicated with the port T, hydraulic oil can enter the lower pressure cavity of the valve driver.

Preferably, the valve actuator includes a housing, an upper spring seat, an upper spring, a plunger, a lower spring, and a lower spring seat, the upper spring seat, the upper spring, the plunger, the lower spring and the lower spring seat are all arranged in the shell, the upper spring seat is in interference fit with the shell, the upper spring seat is positioned at the upper end of the shell, and the upper spring seat is close to the position of the upper oil inlet, one end of the plunger is arranged in an inner hole of the upper spring seat, the lower spring seat is positioned at the lower end of the shell and is in interference fit with the shell, the other end of the plunger penetrates through the lower spring seat and extends out of the valve driver to be connected with the valve, the upper spring is arranged between the upper end of the plunger and the upper spring seat, and the lower spring is arranged between the lower end of the plunger and the lower spring seat.

Preferably, the lower spring seat is welded to the housing.

Preferably, the plunger comprises an upper cylinder, a plunger guide part and a lower cylinder, the upper cylinder is located at the upper end of the plunger guide part, the lower cylinder is located at the lower end of the plunger guide part, the upper cylinder penetrates into the inner hole of the upper spring seat, and the lower cylinder penetrates through the lower spring seat and extends out of the valve driver to be connected with the valve.

Preferably, a longitudinal slit having a length greater than that of the plunger guide is provided on an inner wall of the housing, the longitudinal slit being capable of communicating the upper pressure chamber and the lower pressure chamber when the plunger reaches a maximum stroke.

Preferably, four longitudinal slits are provided on the inner wall of the housing.

Preferably, go up the spring holder and be provided with the spring holder hole, the spring holder hole be used for with the upper portion cylinder matches, the side of going up the spring holder is provided with U type hole and round hole, U type hole with the round hole is used for the outflow of the hydraulic oil in the upper portion cylinder.

Preferably, the lower spring seat is provided with a lower spring seat inner hole, and the lower spring seat inner hole is matched with the lower cylinder through a matching part.

As a second aspect of the present invention, there is provided a hydraulic variable valve driving system, wherein the hydraulic variable valve driving system includes a control device and the hydraulic variable valve driving device described above, the control device is connected to a two-position four-way valve of the hydraulic variable valve driving device, and the control device is configured to control a communication state of the two-position four-way valve.

The hydraulic variable valve driving device provided by the invention controls the on-off of the high-pressure stabilizing source with stable pressure and the upper and lower cavities of the valve driver by controlling the two-position four-way valve, so that the valve can be opened and closed at any time. And because the valve is closed and is driven by hydraulic pressure, the parts such as a valve spring, a spring disc, a spring lock and the like on the engine can be eliminated, and the number of the parts is reduced.

Drawings

The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the principles of the invention and not to limit the invention. In the drawings:

FIG. 1 is a schematic diagram of a first structure of a Fieldett scheme of the prior art.

FIG. 2 is a first schematic diagram of a prior art Bibo strategy.

FIG. 3 is a schematic diagram of a second structure of the Fieldt protocol of the prior art.

FIG. 4 is a second schematic diagram of a prior art Bibo strategy.

Fig. 5 is a schematic sectional view showing a hydraulic variable valve actuating apparatus according to the present invention.

Fig. 6 is a schematic cross-sectional structure diagram of a valve actuator provided by the present invention.

Fig. 7 is a schematic cross-sectional structure diagram of the plunger provided by the present invention.

Fig. 8 is a schematic cross-sectional view of a longitudinal slit provided in the housing according to the present invention.

Fig. 9 is a schematic cross-sectional structure view of an upper spring seat provided by the present invention.

Fig. 10 is a schematic cross-sectional structure view of a lower spring seat provided by the present invention.

FIG. 11 is a graph illustrating the relationship between valve lift and flow area provided by the present invention.

Fig. 12 is a schematic structural view of a hydraulic variable valve actuation system provided by the present invention.

Detailed Description

The following detailed description of embodiments of the invention refers to the accompanying drawings. It should be understood that the detailed description and specific examples, while indicating the present invention, are given by way of illustration and explanation only, not limitation.

As a first aspect of the present invention, there is provided a hydraulic variable valve driving device 100, wherein, as shown in fig. 5 and 6, the hydraulic variable valve driving device includes: a high-pressure stabilizing source 1, a low-pressure accumulating mechanism 2, a two-position four-way valve 3, a valve driver 4 and a valve 5,

the output end of the high-pressure stabilizing source 1 is connected with a port P of the two-position four-way valve 3, the low-pressure accumulating mechanism 2 is connected with a port T of the two-position four-way valve 3, an upper oil inlet 11 of the valve driver 4 is connected with a port A of the two-position four-way valve 3, a lower oil inlet 13 of the valve driver 4 is connected with a port B of the two-position four-way valve, and a plunger 40 of the valve driver 4 is connected with the valve 5;

the communicating state of each port of the two-position four-way valve 3 can control the high-pressure stabilizing source 1 and the on-off of the upper pressure cavity and the lower pressure cavity of the valve driver 4, when hydraulic oil enters the upper pressure cavity 41 of the valve driver 4, the valve driver 4 can push the valve 5 under the control of the high-pressure stabilizing source 1 to be opened, when the hydraulic oil enters the lower pressure cavity 42 of the valve driver 4, the valve driver 4 can push the valve 5 to be closed under the control of the high-pressure stabilizing source 1, and the low-pressure accumulation mechanism 2 can temporarily store the hydraulic oil when the pressure state of the high-pressure stabilizing source 1 is switched.

Specifically, when the port P and the port a of the two-position four-way valve 3 are communicated, and the port B and the port T are communicated, hydraulic oil can enter the upper pressure chamber of the valve actuator 4, and when the port P and the port B of the two-position four-way valve 3 are communicated, and the port a and the port T are communicated, hydraulic oil can enter the lower pressure chamber of the valve actuator 4.

The working principle of the hydraulic variable valve driving device is as follows: the valves are driven to open and close by hydraulic pressure. The specific working process is to control the on-off of the high-pressure stabilizing source 1 with stable pressure and the upper and lower cavities of the valve driver 4 by controlling the two-position four-way valve 3. When the port P of the two-position four-way valve 3 is communicated with the port A and the port B is communicated with the port T, hydraulic oil enters an upper pressure cavity 41 in the valve driver 4 to push the valve to open; when the port P of the two-position four-way valve 3 is communicated with the port B and the port A is communicated with the port T, hydraulic oil enters a lower pressure cavity 42 in the valve driver 4 to push the valve to close. Thus, the valve 5 can be opened and closed at any time by controlling the position of the two-position four-way valve 3.

It should be noted that the high-pressure regulator 1 includes, but is not limited to, a source for providing stable hydraulic pressure by using an oil pump.

As a specific embodiment of the valve actuator 4, as shown in fig. 6, the valve actuator 4 includes a housing 10, an upper spring seat 20, an upper spring 30, a plunger 40, a lower spring 50, and a lower spring seat 60, the upper spring seat 20, the upper spring 30, the plunger 40, the lower spring 50, and the lower spring seat 60 are all installed in the housing 10, the upper spring seat 20 is in interference fit with the housing 10, the upper spring seat 20 is located at the upper end of the housing 10, the upper spring seat 20 is close to the upper oil inlet 11, one end of the plunger 40 is installed in an inner hole of the upper spring seat 20, the lower spring seat 60 is located at the lower end of the housing 10, the lower spring seat 60 is in interference fit with the housing 10, and the other end of the plunger 40 passes through the lower spring seat 60 and extends out of the valve actuator 4 to be connected to the valve 5, the upper spring 30 is installed at a position where the upper end of the plunger 40 contacts the upper spring seat 20, and the lower spring 50 is installed at a position between the lower end of the plunger 40 and the lower spring seat 60.

Preferably, lower spring seat 60 is welded to housing 10.

Specifically, the upper spring seat 20 and the upper spring 30 are installed in the housing 10 in this order from below the housing 10, and the upper spring seat 20 is interference-fitted with the housing 10. The plunger 40 is installed in the housing 10 from below the housing 10. The lower spring 50 is installed in the housing 10 from below the housing 10. Lower spring seat 60 is installed in housing 10 from bottom to top, lower spring seat 60 and housing 10 are in interference fit, and after lower spring seat 60 is installed, lower spring seat 60 and housing 10 are welded together. The valve 5 is attached to the cylinder head in such a way that the valve 5 is connected to the plunger 40. In the initial state, the valve 5 is kept closed by the spring force of the lower spring 50.

The specific working principle is as follows: the upper oil inlet 11 and the lower oil inlet 13 are respectively communicated with the A, B position of the two-position four-way valve 3, the pressure stabilizing source 1 is connected with the P position of the two-position four-way valve, and the low-pressure oil drainage port is T.

1) At the time of shutdown

When not electrified, the initial position of the two-position four-way valve 3 is that the port P is communicated with the port B, and the port A is communicated with the port T. At this time, since there is no pressure in the high pressure source 1 and the low pressure accumulating mechanism 2, the upper and lower pressure chambers of the valve actuator 4 also have no pressure, the elastic force of the lower spring 50 is larger than that of the upper spring 30, and the valve 5 is kept closed by the lower spring 50.

2) Eliminating influence of valve deformation

When the valve is closed, the port P of the two-position four-way valve 3 is communicated with the port B, and the port A is communicated with the port T. The lower pressure cavity 42 of the valve driver 4 is communicated with the high-pressure stabilizing source 1, when the valve 5 is lengthened due to temperature change, the plunger 40 moves upwards, hydraulic oil in the lower pressure cavity 42 is rapidly supplemented, and therefore the influence of deformation of the valve 5 is eliminated.

3) Valve opening

And a port P of the two-position four-way valve 3 is communicated with a port A, and a port B is communicated with a port T. The high-pressure stabilizing source 1 is communicated with an upper oil inlet 11 of the valve driver 4, the pressure above the plunger 40 is greater than the pressure below the plunger 40, and the plunger 40 moves downwards under the action of hydraulic pressure to push the valve 5 to open; the lower pressure chamber 42 is communicated with the lower oil inlet 13, and the plunger 40 moves downwards to push out the hydraulic oil in the lower pressure chamber 42 into the low-pressure accumulation mechanism 2. The speed of movement of the plunger 40 and valve 5 is dependent on the pressure within the high pressure regulator 1, with the higher the pressure the faster the response of the valve 5 movement.

4) When the valve is opened to the maximum position

First, as the opening height of the valve 5 increases, the compression height of the upper spring 30 decreases, the spring force decreases, the compression height of the lower spring 50 increases, the spring force increases, the lower spring 50 is a variable rate spring, and the spring force of the lower spring 50 increases abruptly at the point where the valve 5 is about to reach the maximum lift, thereby reducing the impact of the plunger 40 on the lower spring seat 60.

In addition, when the valve 5 reaches the maximum lift, the two-position four-way valve 3 is controlled, so that the upper pressure cavity 41 is disconnected from the high-pressure stabilizing source 1, the lower pressure cavity 42 is communicated with the high-pressure stabilizing source 1, the pressure of the upper pressure cavity 41 is reduced, the pressure of the lower pressure cavity 42 is increased, the pressure of the lower pressure cavity 42 is greater than that of the upper pressure cavity 41, and the lift of the valve 5 is reduced.

It should be noted that when the valve 5 is opened, the valve 5 is separated from a valve seat 80 on the engine, and when the valve 5 is closed, the valve 5 is in contact with the valve seat 80 on the engine, and the valve seat 80 on the engine is used to improve the sealing between the valve 5 and the engine.

Specifically, as shown in fig. 7, the plunger 40 includes an upper cylinder 401, a plunger guide 402, and a lower cylinder 403, the upper cylinder 401 is located at the upper end of the plunger guide 402, the lower cylinder 403 is located at the lower end of the plunger guide 402, the upper cylinder 401 penetrates into the inner hole of the upper spring seat 20, and the lower cylinder 403 extends out of the valve actuator 4 through the lower spring seat 60 and is connected to the valve 5.

It should be noted that, as shown in fig. 11, in the matching form of the upper spring seat 20 and the upper cylinder 401, as the plunger 40 moves upward, a change curve of the flow area between the upper spring seat 20 and the upper cylinder 401 along with the displacement of the plunger is specifically: as the valve lift is decreased, the flow area gradually decreases, including but not limited to the features shown in fig. 11, where the flow area remains constant first, then decreases rapidly, and finally decreases slowly.

Further specifically, as shown in fig. 8, a longitudinal slit 12 is provided on the inner wall of the housing 10, the length of the longitudinal slit 12 is greater than the length of the plunger guide 402, and the longitudinal slit 12 is capable of communicating the upper pressure chamber 41 and the lower pressure chamber 42 when the plunger 40 reaches the maximum stroke.

Preferably, four longitudinal slits 12 are provided on the inner wall of the housing 10.

It will be appreciated that the inner wall of the housing 10 is designed with a longitudinal slit 12 having a length greater than the length of the guide 402 of the plunger 40. The function of the longitudinal cut 12 is to prevent the valve lift from exceeding the maximum design lift. When the valve reaches the maximum lift and the position of the two-position four-way valve is not switched, the pressure of the upper pressure cavity 41 is still larger than that of the lower pressure cavity 42, once the valve exceeds the maximum lift, the four notches on the inner wall of the shell 10 are communicated with the upper pressure cavity and the lower pressure cavity, the pressure of the upper pressure cavity 41 is rapidly reduced, the pressure of the upper pressure cavity and the pressure of the lower pressure cavity are balanced, and as the resultant force direction of the upper spring force and the lower spring force applied to the plunger 4 is upward, the plunger gradually stops descending and starts ascending, the valve lift is reduced, and therefore.

And a port P of the two-position four-way valve 3 is communicated with a port B, and a port A is communicated with a port T. The high-pressure stabilizing source 1 is communicated with the lower oil inlet 13, the lower pressure cavity 42 is communicated with the high-pressure source, the pressure of the upper pressure cavity 41 is reduced, the pressure of the lower pressure cavity 42 is increased, the plunger 40 and the valve 70 move upwards under the combined action of the hydraulic pressure and the spring force (the upper spring 30 and the lower spring 50 are both in a compressed state, the lower spring force is greater than the upper spring force), the hydraulic oil in the upper plunger cavity is pushed out to the oil drainage cavity 2, and finally the valve is closed.

Specifically, as shown in fig. 9, the upper spring seat 20 is provided with a spring seat inner hole 23, the spring seat inner hole 23 is used for being matched with the upper cylinder 401, a U-shaped hole 21 and a circular hole 22 are provided on a side surface of the upper spring seat 20, and the U-shaped hole 21 and the circular hole 22 are used for flowing out of hydraulic oil in the upper cylinder 401.

Specifically, as shown in fig. 10, the lower spring seat 60 is provided with a lower spring seat inner hole 61, and a coupling is arranged between the lower spring seat inner hole 61 and the lower cylinder 403.

When the valve is to be closed, in order to prevent the valve 5 from being seated at an excessive speed, an oil passage with a special structure is designed on the upper spring seat 20, so that when the valve lift is small, the upper cylinder 401 of the plunger 40 enters the spring seat inner hole 23 of the upper spring seat 20, the plunger 40 moves upwards along with the reduction of the valve lift, hydraulic oil in the upper pressure cavity 41 flows out through the U-shaped hole 22 and the small circular hole 21 on the side of the upper spring seat 20, the flow resistance is increased, and the movement speed of the plunger 40 and the valve 70 is reduced.

As the valve lift is further reduced, the plunger 40 is further raised, the hydraulic oil in the upper pressure chamber 41 can only flow out through the circular hole 21, and the flow resistance is further increased due to the small diameter of the circular hole, so that the upward speed of the plunger 40 is reduced, and the speed of seating the valve is further reduced.

Since the upper spring 30 is a variable rate spring, the rate of the upper spring becomes large when the valve is about to close, and when the plunger 40 moves upward, the downward pressure of the spring on the plunger increases greatly, which reduces the valve seating velocity and relieves the impact of the valve on the valve seat.

The plunger 40 is installed into the housing 10 from below to above, the lower spring 50 and the lower spring seat 60 are installed into the housing 10 from below to above, the lower spring seat 60 and the housing 10 are fixed by a special jig, and then the lower spring seat 60 and the housing 10 are welded together. The lower spring seat inner bore 61 and the lower cylinder 403 are a clearance fit.

It should also be noted that in fig. 10, the lower spring seat 60 includes a first feature 62 and a second feature 63, where the first feature 62 and the second feature 63 are critical dimension features, a spring needs to be installed on the first feature 62, and the second feature 63 has a sealing function.

Therefore, the hydraulic variable valve driving device provided by the invention can realize the opening and closing of the valve at any time and control the opening duration of the valve because the opening and closing of the valve are driven by hydraulic pressure. Therefore, the accurate control of the air intake and exhaust amount of the engine can be realized, and the accurate control of the residual waste gas in the cylinder can be further realized, so that the aims of optimizing combustion, improving heat efficiency and reducing harmful emission of the engine are fulfilled. In addition, the hydraulic variable valve driving device provided by the invention can also effectively control the valve seating speed, so that the valve seating impact is reduced, and the system reliability is improved; the reduction in valve seating velocity reduces the impact of the valve with the valve seat insert, thereby reducing engine vibration noise.

As a second aspect of the present invention, there is provided a hydraulic variable valve driving system, wherein, as shown in fig. 12, the hydraulic variable valve driving system 200 includes a control device 110 and the hydraulic variable valve driving device 100 described above, the control device 110 is connected to a two-position four-way valve of the hydraulic variable valve driving device 100, and the control device 110 is used for controlling a communication state of the two-position four-way valve.

According to the hydraulic variable valve driving system provided by the invention, the high-pressure stabilizing source with stable pressure and the upper and lower cavities of the valve driver are controlled to be switched on and off by controlling the two-position four-way valve, so that the valve can be opened and closed at any time. And because the valve is closed and is driven by hydraulic pressure, the parts such as a valve spring, a spring disc, a spring lock and the like on the engine can be eliminated, and the number of the parts is reduced.

It will be understood that the above embodiments are merely exemplary embodiments taken to illustrate the principles of the present invention, which is not limited thereto. It will be apparent to those skilled in the art that various modifications and improvements can be made without departing from the spirit and substance of the invention, and these modifications and improvements are also considered to be within the scope of the invention.

Claims

1. A hydraulic variable valve driving device, characterized by comprising: a high-pressure stabilizing source, a low-pressure accumulating mechanism, a two-position four-way valve, a valve driver and a valve,

the communication state of each port of the two-position four-way valve can control the on-off of the high-pressure stabilizing source and the upper and lower pressure cavities of the valve driver, when hydraulic oil enters the upper pressure cavity of the valve driver, the valve driver can push the valve to open under the control of the high-pressure stabilizing source, when hydraulic oil enters the lower pressure cavity of the valve driver, the valve driver can push the valve to close under the control of the high-pressure stabilizing source, and the low-pressure accumulation mechanism can temporarily store the hydraulic oil when the high-pressure stabilizing source switches the pressure state;

the valve driver comprises a shell, an upper spring seat, an upper spring, a plunger, a lower spring and a lower spring seat, the upper spring seat, the upper spring, the plunger, the lower spring and the lower spring seat are all arranged in the shell, the upper spring seat is in interference fit with the shell, the upper spring seat is positioned at the upper end of the shell, and the upper spring seat is close to the position of the upper oil inlet, one end of the plunger is arranged in an inner hole of the upper spring seat, the lower spring seat is positioned at the lower end of the shell and is in interference fit with the shell, the other end of the plunger penetrates through the lower spring seat and extends out of the valve driver to be connected with the valve, the upper spring is arranged between the upper end of the plunger and the upper spring seat, and the lower spring is arranged between the lower end of the plunger and the lower spring seat;

the plunger comprises an upper cylinder, a plunger guide part and a lower cylinder, the upper cylinder is positioned at the upper end of the plunger guide part, the lower cylinder is positioned at the lower end of the plunger guide part, the upper cylinder penetrates into an inner hole of the upper spring seat, and the lower cylinder penetrates through the lower spring seat and extends out of the valve driver to be connected with the valve;

the inner wall of the shell is provided with a longitudinal cut, the length of the longitudinal cut is larger than that of the plunger guiding part, and the longitudinal cut can communicate the upper pressure cavity and the lower pressure cavity when the plunger reaches the maximum stroke.

2. The hydraulic variable valve actuation device according to claim 1, wherein when port P of the two-position four-way valve communicates with port a and port B communicates with port T, hydraulic oil can enter an upper pressure chamber of the valve actuator, and when port P of the two-position four-way valve communicates with port B and port a communicates with port T, hydraulic oil can enter a lower pressure chamber of the valve actuator.

3. The hydraulic variable valve actuation device according to claim 1, wherein the lower spring seat is welded to the housing.

4. The hydraulic variable valve actuation device according to claim 1, wherein four longitudinal slits are provided on the inner wall of the housing.

5. The hydraulic variable valve actuation device according to claim 1, characterized in that the upper spring seat is provided with a spring seat inner hole for matching with the upper cylinder, and a side surface of the upper spring seat is provided with a U-shaped hole and a circular hole for outflow of hydraulic oil in the upper cylinder.

6. The hydraulic variable valve actuation device according to claim 1, wherein the lower spring seat is provided with a lower spring seat inner bore, and a mating member is provided between the lower spring seat inner bore and the lower cylinder.

7. A hydraulic variable valve driving system characterized by comprising a control device and the hydraulic variable valve driving device according to any one of claims 1 to 6, the control device being connected to a two-position four-way valve of the hydraulic variable valve driving device, the control device being configured to control a communication state of the two-position four-way valve.