KR101623222B1 - Variable valve timing system using hydraulic system - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a variable valve timing device using a hydraulic pressure, and an object thereof is to provide a variable valve timing device using hydraulic pressure capable of controlling an oil pressure applied to an upper plunger in accordance with a flow of oil pressure, .
The present invention is characterized in that an upper chamber and a lower chamber are formed in a barrel housing, an upper plunger connected to a valve assembly is provided in the upper chamber, a lower plunger is vertically moved by a cam profile in the lower chamber, And the lower chamber are connected by a plurality of flow paths,
An open valve and a close valve are provided on one side flow path connected to the upper chamber and the lower chamber to adjust the intake timing and the exhaust timing of the valve by controlling the up and down movement of the upper plunger through the hydraulic flow control of the upper chamber and the lower chamber. .

Description

[0001] The present invention relates to a variable valve timing system using hydraulic pressure,

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a variable valve timing device using hydraulic pressure, and more particularly, to a variable valve timing device using hydraulic pressure capable of adjusting a valve timing by the flow of hydraulic pressure in accordance with an operation of an open valve and a close valve.

As the age of environmentally friendly and highly efficient engines is approaching, the performance of various engines is demanding. The performance of the engine is determined by the explosion of the fuel, the suction of the air and the discharge timing of the exhaust gas. In order to optimize the intake and exhaust in the engine, different valve timing is required depending on the speed of the engine. And the like, the timing of the opening and closing of the intake and exhaust valves changes the timing of the variable valve timing of the engine so as to optimize the thermal efficiency and the output and improve the fuel efficiency.

As a general technique related to the variable valve timing device, there is a device for changing the phase of the cam to advance the opening timing of the valve to advanced or retarded. In the conventional engine, The cam profile controls the opening and closing of the valve using the combustion drive system.

However, such a variable valve timing device can not be changed during the operation of the engine unless the cam is changed. The variable valve timing device is provided with a helical gear type, a torsional spline type, a vane type, or an electrohydraulic type at the front end portion of the camshaft The cam phase change mechanism is required to be provided, which has a disadvantage in that the configuration becomes very complicated and the size of the cylinder head portion becomes uneven.

As another example of the variable valve timing device, there is known a device that changes the structure of the valve lift mechanism to change the open duration and the opening / closing timing of the valve. However, such a device is also structurally complicated and has various problems such as increasing the volume of the cylinder head portion.

In order to solve the above problems, there has been proposed a variable valve timing overhead valve device (10-2010-0107082), which is a patent application filed by the applicant of the present invention, namely a change in valve clearance and a contact between a push rod and a rocker arm By changing the timing of the valve so that the contact point of the roller to the cam can be moved without changing the position, it can be easily applied to the overhead valve devices of heavy and large engines for marine and industrial applications, An overhead valve device for variable valve timing which is usefully applicable to an overhead valve device of a small engine such as an automobile engine,

There is a variable valve timing device (10-2011-0042228) which is a helical cut type plunger capable of adjusting a valve timing by vertically moving a plunger formed by symmetrical two helical cut faces by hydraulic pressure.

An object of the present invention is to provide a variable valve timing device using hydraulic pressure capable of controlling an intake timing and an exhaust timing by controlling an oil pressure applied to an upper plunger in accordance with a flow of hydraulic pressure .

It is still another object of the present invention to provide a variable valve timing device using hydraulic pressure capable of improving the performance of the engine by changing the valve timing timing according to the load or rotation speed required by the engine.

The present invention is characterized in that an upper chamber and a lower chamber are formed in a barrel housing, an upper plunger connected to a valve is installed in the upper chamber, a lower plunger is installed in the lower chamber to move along a campfile, The lower chamber is connected by a plurality of flow paths and an open valve and a close valve are provided in the flow path to control the up and down movement of the upper plunger through the hydraulic flow control of the upper chamber and the lower chamber, Respectively.

As described above, according to the present invention, the hydraulic pressure delivered to the upper plunger is controlled by the open valve and the close valve, so that the optimal valve timing can be adjusted in accordance with the engine load and the number of revolutions without a separate mechanism.

Further, according to the present invention, a plurality of flow paths connecting the upper chamber and the lower chamber can be adjusted by an open valve and a close valve, so that the timing of the four steps can be adjusted. Further, Do.

Further, it is possible to improve the performance of the engine by changing the point of time according to the load (load) or the rpm required by the engine, and the thermal efficiency can be improved and the fuel consumption rate can be reduced by this effect.

In addition, in the conventional mechanical valve train system, since the movement of the valve is determined by the profile of the cam, the opening and closing timing of the valve is difficult to change unless the shape of the cam is changed. However, There are many effects such as having various valve timing and duration with fixed profile alone.

1 is an illustration showing a configuration according to the present invention;
Figure 2 is an exemplary illustration of an internal configuration according to the present invention.
Fig. 3 is an exemplary diagram showing a hydraulic circuit according to the present invention. Fig.
Fig. 4 is an exemplary view showing an operating state in the open state of the closing valve of the present invention
5 is an exemplary view showing an operating state in the closed state of the open / closed valve of the present invention
6 is an exemplary view showing an operating state in the open / closed valve open state of the present invention
7 is an exemplary view showing an operating state in an open valve state of the present invention

FIG. 1 is an exemplary view showing a configuration according to the present invention, FIG. 2 is an exemplary view showing an internal configuration according to the present invention, FIG. 3 is an exemplary view showing a hydraulic circuit according to the present invention,

The present invention provides an upper chamber 11 and a lower chamber 12 in a barrel housing 10 and an upper plunger 20 connected to a push rod 91 in the upper chamber 11, A lower plunger 30 is disposed in the chamber 12 to move along a cam profile and the upper chamber 11 and the lower chamber 12 are connected by a plurality of flow paths, A close valve 50 is provided to control the up and down movement of the upper plunger 20 through the hydraulic flow control of the upper chamber 11 and the lower chamber 12 to adjust the intake timing and the exhaust timing of the valve .

That is, according to the present invention, there are provided a barrel housing 10 having an upper chamber 11 formed on an upper portion thereof and a lower chamber 12 formed on a lower portion thereof,

An upper plunger 20 inserted into the upper chamber 11 and connected to the push rod 91;

A lower plunger (30) inserted into the lower chamber (12) and connected to the lower roller assembly (80) by a cam profile to move up and down;

A spring 61 is supported by the upper plunger 20 and a lower spring 62 is supported by the lower plunger 30 and an immersion rod emergency rod, 60);

A supply passage 70 for supplying L.O into the lower chamber 12;

A first flow path 71 having one side connected to the supply flow path 70 and the other side connected to the upper chamber 11 and having a first check valve 71a;

An open channel 41 connected to the lower chamber 12 to be positioned below the supply channel 70 and having an open valve 40;

A second flow path 72 connected to the upper chamber 11 and having a second check valve 72a;

An upper return flow passage 51 having one side connected to the second flow path 72 and the other side connected to the lower chamber 12 and having a close valve 50;

A lower return flow path 73 disposed below the upper return flow path 51 and having one side connected to the second flow path 72 and the other side connected to the lower chamber 12;

And a spill port 74 connected to the lower chamber 12 so as to be positioned below the lower return flow path 73 and discharging the LO.

The barrel housing 10 includes an upper chamber 11, a lower chamber 12, a first flow path 71, a second flow path 72, an open flow path 41, an upper return flow path 51, A flow path 73, a spill port 74, and the like are formed.

The barrel housing 10 may be formed separately from the housing body 13 and the flow path block 14 for the sake of workability. When the barrel housing 10 is separately formed, the housing body 13 is provided with the upper chamber 11, And the lower chamber 12 are formed in the upper and lower return passages 71 and 74. The first and second return passages 71 and 72, the open passage 41, the upper return passage 51, the lower return passage 73, Is connected to the housing main body 13 and the flow path block 14.

The upper plunger 20 receives hydraulic pressure from the lower plunger 30 and moves up and down in the upper chamber 11 to move the push rod 91 of the valve assembly 90 to open and close the valve. An actuating plunger 21 connected to the push rod 91 is connected to the upper plunger 20.

The lower plunger 30 is connected to a roller assembly 80 moved along the cam profile, and is moved up and down in the lower chamber 12 by the cam profile.

The immersion rod 60 is inserted into the barrel housing 10 such that the upper portion thereof is located in the upper chamber 11 and the lower portion is located in the lower chamber 12. The upper plunger 20 and the lower plunger 30, Respectively, by springs 61 and 62, respectively.

Such an emergency load 60 is intended to have advantages in restoring the hydraulic pressure and the system by minimizing the engine driving without sudden stopping of the engine upon failure of the hydraulic pressure when the hydraulic pressure fails.

That is, under normal conditions, the immersion rod will not make metal contact with the upper and lower plungers, which is realized through the buffering action of the spring. More specifically, when an abnormality occurs in the hydraulic flow, the distance held between the upper and lower plungers in a normal state is lost (spring compression), and the lower plunger, the immersion rod, and the upper plunger are brought into metal contact, As shown in FIG. This can not deliver 100% of the normal motion of the cam perfectly, but it can realize the shape that enables minimum engine driving. This is possible by determining the distance between items.

The supply passage 70 has a check valve 70a for preventing the backflow of the LO in the lower chamber 12 by a flow path for supplying the LO into the lower chamber 12. [ The spill port 74 is a flow path for discharging the LO in the lower chamber 12 and the LO supplied through the supply flow path 70 is discharged through the spill port 74.

The first channel 71 is connected to the supply channel 70 so as to communicate with the lower chamber 12 and the other channel is connected to the upper chamber 11. The high pressure fluid A first check valve 71a is provided to prevent backflow of the refrigerant.

The open channel 41 is connected to the lower chamber 12 so as to be located below the supply channel 70 and is formed in the barrel housing 10 and is opened and closed by the open valve 40, And discharging the LO to the outside.

The second flow path 72 is for returning the high pressure fluid in the upper chamber 11 to the lower chamber 12 and is connected to the upper chamber 11 at one side and the other side to the lower chamber 12 The second return passage 51 is formed in the barrel housing 10 so as to be connected to the upper portion of the upper return passage 51 and the upper portion of the upper return passage 51, A check valve 72a is provided.

The upper return flow passage 51 is opened and closed by the operation of the close valve 50 to return the high pressure fluid returned from the upper chamber 11 through the second flow passage 72 into the lower chamber 12. At this time, the upper return flow passage 51 is connected to the lower chamber 12 so as to be located at a position where the lower plunger 30 is not blocked by the upper plunger 30 even when the lower plunger 30 reaches the maximum.

The open valve (40) and the close valve (50) operate through an engine governor and are controlled by control air or electrical signals. In other words, in the governor, the engine controls the load and the RPM. The optimum intake valve timing is set at each required load so that the governor (load) Governor can operate an open close valve using control air or electrical signals.

The lower return channel 73 is opened by the lower plunger 30 moving up and down in the lower chamber 12 and returns to the lower chamber 12 a high-pressure fluid returned through the second flow channel 72. That is, when the one end of the lower portion communicating with the lower chamber is opened by the lower plunger 30, the high-pressure fluid returned into the second flow path 72 through the second check valve 72a is supplied to the lower chamber 12).

Reference numeral 17 denotes a middle housing, reference numeral 18 denotes a lower housing, and reference numeral 85 denotes a cam.

Hereinafter, the flow of the LO according to the operation of the open valve and the close valve of the present invention and the operation state of the upper plunger accordingly will be described in detail with reference to FIGS.

FIG. 4 is a view showing an example of the operating state in the open state of the closing valve of the present invention, that is, in the normal opening & normal closing driving sequence, that is, when the closing valve is opened Is shown.

The lower plunger 30 rises to close the spill port 74 to terminate the LO discharge through the spill port and to close the first check valve 71 of the first flow path 71. [ The valve 71a is opened so that the LO in the lower chamber 12 flows into the upper chamber 11 through the first flow path 71. [ At this time, since the pressure of the lower chamber 12 is equal to or higher than the pressure of the upper chamber 11 in the second flow path 72, the return (upper and lower return) of the LO through the upper return flow path 51 and the lower upper part does not occur So that the upper plunger 20 is raised. At this time, the lower plunger 30 does not block the upper return line 51 even when the lower plunger 30 reaches the maximum.

The lower plunger 30 starts to descend and the pressure of the lower chamber 12 is lowered so that the second check valve 72a of the second flow path 72 And the LO returns to the lower chamber 12 through the upper return flow path 51.

The LO in the upper chamber 11 is introduced into the lower chamber 12 by the return of the LO through the upper return channel 51 so that the upper plunger 20 It begins to descend.

When the lower plunger 30 is further lowered, the upper portion of the upper plunger 20 is opened and the return of the LO through the upper portion of the lower portion is started, thereby returning the upper plunger 20 to the initial start state.

FIG. 5 is a view illustrating an operation state of the open / close valve in the closed state according to an embodiment of the present invention. In the normal open & late closing drive sequence, Are all closed.

The lower plunger 30 rises to close the spill port 74 to terminate the LO port of the spill port and to close the spill port of the first flow path 71. [ The first check valve 71a is opened so that the LO in the lower chamber 12 flows into the upper chamber 11. [ At this time, since the pressure of the lower chamber 12 is equal to or higher than the pressure of the upper chamber 11 in the second flow path 72, the return (upper and lower return) of the LO occurs through the upper return flow path 51 and the lower upper part So that the upper plunger 20 is raised.

At this time, the lower plunger 30 does not block the upper return line 51 even when the lower plunger 30 reaches the maximum.

The lower plunger 30 begins to descend when the cam descending section starts, but the upper return flow path 51 is closed by the close control valve 50 so that the upper return flow path 51 is closed The lower pressure of the lower chamber 12 is lowered so that the lowering pressure is partially complemented through the supply line 71 and the lower plunger 30 ) Continues to descend.

At this time, the upper plunger 20 is not lowered until the lower return of the LO is made through the lower portion, and the lower plunger 30 is further lowered, so that the LO The upper plunger 20 starts to descend and return to the starting position for the first time.

FIG. 6 is an exemplary view showing an operating state in the open / close valve open state according to the present invention, and is a flow chart showing a sequence of operations for late opening and normal closing, that is, an open and close valve Are all open.

The lower plunger 30 rises and the spill port 74 is closed to shut off the LO port of the spill port and then the open control valve The LO in the lower chamber 12 flows out through the open channel 41 and the LO does not enter the first channel 71. [

The first check valve 71a of the first flow path 71 is opened by the oil pressure and the first check valve 71a is opened through the first flow path 71 to the lower chamber 12 are introduced into the upper chamber 11. Since the pressure of the lower chamber 12 in the second flow path 72 is equal to or higher than the pressure of the upper chamber 11, the second check valve 72a of the second flow path 72 causes the upper return flow path 51 and the lower return path 51, Upper & lower return of LO through the upper part does not occur, so that the upper plunger 20 is raised.

At this time, the lower plunger 30 does not block the upper return line 51 even when the lower plunger 30 reaches the maximum.

The lower plunger 30 starts to descend and the pressure of the lower chamber 12 is lowered so that the second check valve 72a of the second flow path 72 The LO in the upper chamber 11 flows into the lower chamber 12 through the upper return line 51 and the upper plunger 20 moves down .

Further, when the cam is further lowered, the lower plunger 30 is lowered by the lowering of the lower plunger 30, and the lower return of the LO is started through the upper portion of the lower plunger 30, State.

FIG. 7 is a view showing an example of the operating state in the open valve state of the present invention. In the order of the late opening and late closing operation, that is, when the open valve is open Is shown.

The lower plunger 30 rises and the spill port 74 is closed to shut off the LO port of the spill port, The LO does not enter the first flow path 71 because the LO flows out through the open flow path 40 by opening the open control valve 41.

The first check valve 71a of the first flow path 71 is opened and the lower chamber 12 is opened through the first flow path 71. As a result, ) Flows into the upper chamber 11. Since the pressure of the lower chamber 12 is equal to or higher than the pressure of the upper chamber 11 in the second flow path 72, the second return flow path 51 and the second return flow path are formed by the second check valve 72a of the second flow path 72, An upper and lower return of the LO through the upper portion of the lower portion is not caused, thereby causing the upper plunger 20 to rise.

When the lowering plunger 30 starts to descend, the upper return flow path 51 is closed by the close control valve 50 and the upper return flow path 51 is closed, The lower pressure is lowered in the lower chamber 12 so that the lowering pressure is partially complemented through the supply line HP 71 and the lower plunger , 30) continue to descend.

At this time, the upper plunger 20 is not lowered until the lower return of the LO is made through the lower portion, and the lower plunger 30 is further lowered, so that the LO The upper plunger 20 starts to descend and return to the starting position for the first time.

4 to 7 illustrate four timing adjustments by an open valve and a close valve. The present invention is not limited to this, as more various timing adjustments are possible through expansion of the number of flow paths.

In addition, the present invention is not limited to the above-described specific preferred embodiments, and various changes and modifications may be made without departing from the scope of the present invention as defined in the appended claims. It is to be understood that such changes and modifications are within the scope of the claims.

(10): barrel housing
(11): upper chamber
(12): a lower chamber (13): a housing body
(14): Euro block
(20): upper plunger
(21): Actuating pluger
(30): lower plunger
(40): open control valve
(41): Open channel
(50): a close control valve
(51): upper return line
(60): Emergency rod
(61, 62): spring
(70): supply path (HP supply)
(71): first flow path (71a): first check valve
(72): second flow path (72a): second check valve
(73): Lower return channel
(74): spill port
(80): a roller assembly
(90): valve assembly
(91): a push rod
(100): variable valve timing device

Claims (4)

A lower plunger is provided in the lower chamber to move up and down by a cam profile, and the upper and lower chambers are provided in the upper chamber and the lower chamber, respectively, Are connected by a plurality of flow paths,
The barrel housing is divided into a housing main body and a flow path block,
An open valve and a close valve are provided on one side flow path connected to the upper chamber and the lower chamber to adjust the intake timing and exhaust timing of the valve by controlling the up and down movement of the upper plunger through the hydraulic flow control of the upper chamber and the lower chamber. Wherein the variable valve timing device comprises:
The method of claim 1,
The variable valve timing device includes:
A barrel housing having an upper chamber formed at an upper portion thereof and a lower chamber formed at a lower portion thereof,
An upper plunger inserted into the upper chamber and connected to the push rod;
A lower plunger inserted into the lower chamber and connected to the lower roller assembly by a lower portion to move up and down by a cam profile;
An emergency rod which is supported by the upper plunger in an upper portion and is supported by another spring at a lower plunger, and which is installed from the upper chamber to the lower chamber;
A supply passage for supplying the LO into the lower chamber;
A first flow path having one side connected to the supply passage and the other side connected to the upper chamber and having a first check valve;
An open channel connected to the lower chamber so as to be positioned below the supply channel and having an open valve;
A second flow path connected to the upper chamber and having a second check valve;
An upper return flow path having one side connected to the second flow path and the other side connected to the lower chamber and having a close valve;
A lower return channel installed to be positioned below the upper return channel, one side connected to the second flow path and the other side connected to the lower chamber;
And a spill port connected to the lower chamber so as to be positioned below the lower return flow channel and discharging the LO.
The method of claim 2,
Wherein the upper return channel is connected to the lower chamber so that the upper return channel is located at a position where the lower plunger is not blocked by the lower plunger even when the lower plunger reaches the maximum.
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