KR100577503B1 - Fluid-flow control valve - Google Patents

Abstract

FIELD OF THE INVENTION The present invention relates to a fluid flow control valve, in particular to properly control the flow rate of a pressurized working fluid generated by a hydraulic pump having a motive force and drive connection, such as an engine of an automobile, and to operate the working fluid with a hydraulic actuator such as a hydraulic power steering device. A fluid flow control valve for supplying a controlled flow of the

The fluid flow control valve according to the present invention for achieving the above object is formed so as to communicate with the inflow passage through which the pressurized fluid flows from the pump and the return passage through which a part of the pressurized fluid is returned to the oil tank and the inflow passage and the return passage. And a housing having a chamber having one end opened to install various components, and installed to be inserted into the chamber of the housing to be linearly driven according to the pressure of the pressurized fluid flowing into the inflow passage to open or close the return passage. A spool that is divided into a first pressure chamber on the inflow passage side and a second pressure chamber on the rear side, a spring provided with one end to the spool and the other end to the chamber of the housing to provide an elastic force for pushing the spool outward of the chamber; Installed and fixed at the inlet of the chamber and having a fluid passage therein. A first orifice communicating with the orifice is formed, and is formed to divide the first pressure chamber into a discharge pressure chamber communicating with the second pressure chamber through an inlet pressure chamber on the inflow passage side and a bypass passage formed in the housing. A connector formed with a passage so that the fluid passage communicates therewith, and a fluid passage formed inside the connector so as to be linearly movable along the axial direction, and having a fluid passage defining a fluid passage of the connector therein. A valve is formed to communicate with the first and second orifices, respectively, and the valve is formed so that the area of the passage communicating with the second orifice is reduced as the fluid pressure is moved. One end is caught inside the connector and the other end is caught by the valve. A spring provided to provide an elastic force to push the valve in a direction opposite to that of the hydraulic pressure; It is composed of a stopper installed in the connector to prevent separation.

Steering System, Hydraulic Pump, Fluid Flow Control Valve, Spool

Description

Fluid Flow Control Valve {FLUID-FLOW CONTROL VALVE}             

1 is an exploded perspective view of a part of the components of the fluid flow control valve according to the present invention disassembled;

2 is a cross-sectional view of a fluid flow control valve according to the present invention, showing a state when the engine speed is the lowest;

3 is a cross-sectional view of a fluid flow control valve according to the present invention, in which the rotation speed of the engine is increased rather than the state shown in FIG.

4 is a cross-sectional view of a fluid flow control valve according to the present invention, in which the rotational speed of the engine is increased rather than the state shown in FIG. 3, and the spool is further moved to immediately before the return passage is opened.

5 is a cross-sectional view of a fluid flow control valve according to the present invention, in which the rotation speed of the engine is greater than that shown in FIG. 4 and the return passage is partially opened.

6 is a cross-sectional view of the fluid flow control valve according to the present invention, in which the rotation speed of the engine is increased than the state shown in FIG. 5 so that the return passage is further opened and the valve of the connector moves so that the cross-sectional area of the second orifice starts to decrease. Drawing showing status,

7 is a cross-sectional view of the fluid flow control valve according to the present invention, in which the rotation speed of the engine is further increased than the state shown in FIG. 6 so that the spool and the valve move further so that the return passage is more opened and the second orifice starts to close. Drawing showing status,

8 is a cross-sectional view of a fluid flow control valve according to the present invention, in which the rotation speed of the engine is increased from the state shown in FIG.

9 is a graph showing a change in discharge flow rate of the working fluid controlled according to the engine speed in the fluid flow valve according to the present invention;

10 is a graph showing a change in the cross-sectional area of the orifice which is a fluid passage flowing into the valve according to the engine speed in the fluid flow valve according to the present invention.

<Explanation of symbols on main parts of the drawings>

1 housing 2 return passage

3: inflow passage 4: bypass

10, 20, Connector 30: Valve

50: spool

FIELD OF THE INVENTION The present invention relates to a fluid flow control valve, in particular to properly control the flow rate of a pressurized working fluid generated by a hydraulic pump having a motive force and drive connection, such as an engine of an automobile, and operating fluid with a hydraulic actuator such as a hydraulic power steering device. A fluid flow control valve for supplying a controlled flow of the

The automobile is a representative vehicle of modern times, which is a combination of many parts, it takes a lot of devices and many parts that make up the car. In such a vehicle, a driver rotates a steering wheel to adjust a driving direction of the vehicle, and a wheel connected to the steering wheel is rotated so that the running direction is adjusted. A steering device that adjusts the driving direction of such a vehicle is called a steering device. The steering device includes a steering wheel, a steering shaft, a steering gear, and a pitman arm. , A drag link, a tie rod, and a steering arm. Among these steering devices, there is a power steering device having a pump for supplying hydraulic pressure for assisting the rotational force of the steering wheel provided by the driver so that the driver can easily rotate the steering wheel. It is operated according to the rotation of the engine to pressurize and supply the fluid. A control valve is installed to control the pressurized fluid supplied from such a pump, which serves to control the flow rate according to the rotation speed of the engine.

Such a control valve should have characteristics such that the flow rate supplied at the low speed rotation of the engine is maximized and controlled at a lower state at the high speed rotation of the engine.

The control valve is usually formed integrally with the pump, and the components of the control valve are inserted into the housing formed in the pump. In the housing of the control valve, an inflow passage through which pressurized fluid flows from the pump and a return passage through which the controlled flow rate flows out into the oil tank are formed, and the return passage is controlled by a spool provided with elastic force by a spring. The pressurized fluid introduced into the inflow passage is partially returned through the return passage as the engine speed increases, and the portion is discharged through the discharge passage as the working fluid. Then, the cross-sectional area of the orifice which is the passage of the pressurized fluid discharged to the discharge passage is changed according to the movement of the valve to control the flow rate.

Most of the control valves have the above-described configuration, and the prior art can be exemplified by Korean Patent Registration No. 217526.

The above patent is configured to control the flow rate of the pressurized fluid flowing from the pump and discharged into the working fluid by the movement of the spool and the movement of the valve of the connector assembly. That is, at a low speed, the spool blocks the return passage so that most of the pressurized fluid is discharged as the working fluid, the valve is positioned at the home position, and the discharge passage is operated to the maximum, and at high speed, the spool opens the return passage. The valve also controls the flow rate of the discharged working fluid in such a way that the discharge passage becomes smaller while the valve also compresses the spring.

However, the conventional control valve has a problem in that the configuration is complicated and the manufacturing cost increases because not only many parts are used but also various passages must be formed in the housing in order to exhibit the response characteristics of the control valve described above.

The present invention has been made to solve the above problems of the prior art, an object of the present invention is to provide a fluid flow control valve that can accurately represent the response characteristics of the control valve in a simple configuration.

The fluid flow control valve according to the present invention is configured to communicate with an inflow passage through which pressurized fluid flows from a pump, a return passage through which a part of the pressurized fluid returns to an oil tank, and the inflow passage and a return passage, and various components are installed. A housing having an open end and a chamber installed at the end thereof so as to be inserted into the chamber of the housing to be linearly driven according to the pressure of the pressurized fluid flowing into the inflow passage, thereby opening or closing the return passage and opening the chamber to a first pressure on the inflow passage side. A spool that is divided into a seal and a second pressure chamber in the rear, a spring provided at one end to the spool and the other end to the chamber of the housing to provide an elastic force for pushing the spool outward of the chamber, and installed and fixed at the inlet of the chamber And a fluid passage therein, the first orifice and the second orifice communicating with the fluid passage, respectively. A piece is formed and formed so as to divide the first pressure chamber into a discharge pressure chamber communicating with the second pressure chamber through an inlet pressure chamber on the inflow passage side and a bypass passage formed in the housing, and a passage is formed so that the fluid passage communicates with the discharge pressure chamber. A connector formed and a fluid passage formed in the connector so as to be linearly movable along the axial direction and having a fluid passage formed therein to form a fluid passage of the connector and communicating the fluid passage to the first and second orifices of the connector A valve is formed so that the area of the passage communicating with the second orifice decreases as it is moved by the fluid pressure, and one end is installed to the inside of the connector and the other end to the valve so that the hydraulic pressure acts on the valve. A spring providing an elastic force pushing in the opposite direction to prevent the valve from being detached from the connector; It characterized in that it comprises a stopper installed in the rotor.

In addition, the valve is formed in a cylindrical shape with the front open, is installed to be movable along the axial direction inside the connector, the front end is formed with a step to reduce the outer diameter of a predetermined length, so that one end is caught on the step It is preferable that the rear end face is formed with a hole communicating with the first orifice, and in the outer diameter of the center is formed an annular groove and a hole communicating with the annular groove and the inner fluid passage to communicate with the second orifice.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

1 is an exploded perspective view of a part of components of a fluid flow control valve according to the present invention in an exploded state, and FIG. 2 is a cross-sectional view of the fluid flow control valve according to the present invention, wherein the engine speed is the lowest. 3 is a cross-sectional view of a fluid flow control valve according to the present invention, in which the rotation speed of the engine is increased rather than the state shown in FIG. 2 and the spool starts to move slightly, FIG. FIG. 5 is a cross-sectional view of a fluid flow control valve according to an embodiment of the present invention, in which a rotation speed of the engine is increased rather than the state shown in FIG. Fig. 6 is a cross-sectional view of a state in which the engine speed is greater than that shown in Fig. 4 and the return passage is partially open. Fig. 6 is a fluid flow according to the present invention. Fig. 7 is a cross-sectional view of the control valve, in which the engine speed is increased than the state shown in Fig. 5 so that the return passage is further opened and the valve of the connector is moved so that the cross-sectional area of the second orifice starts to decrease. A cross-sectional view of a fluid flow control valve according to the present invention, in which the engine speed is further increased than the state shown in FIG. 6 so that the spool and the valve move further so that the return passage is further opened and the second orifice starts to close. 8 is a cross-sectional view of a fluid flow control valve according to the present invention, in which the rotation speed of the engine is increased from the state shown in FIG. 7 to show the state in which the spool and the valve are moved to the maximum, and FIG. A graph showing a change in the discharge flow rate of the working fluid controlled according to the engine speed in the flow valve, FIG. 10 is a fluid flow valve according to the present invention. Therefore, it is a graph showing the change of the cross-sectional area of the orifice which is the fluid passage flowing into the valve according to the engine speed.

The fluid flow control valve according to the present invention is configured such that the pressurized fluid flowing from the pump has a response characteristic according to the engine speed shown in FIGS. 9 and 10 as described above. That is, when the discharge flow rate is low according to the engine speed, it is rapidly increased and then maintains the maximum discharge amount for a certain period of time, and then when the engine speed becomes higher, the discharge flow rate is reversed and then maintains the constant discharge amount again. It is configured to have. This is because steering requires a lot of power at low speeds while driving a car and less force at high speeds than at low speeds.

Fluid flow control valve according to the present invention is configured to exhibit the above-described response characteristics, as shown in Figure 1 in the chamber formed in the housing 1, the spring 60, the spool 50, and the valve ( The connectors 10 and 20 formed of the front member 10 and the rear member 20 on which the 30 is installed are inserted in order, and the connectors 10 and 20 are installed to be fixed to the inlet of the chamber. The chamber is formed in the housing 1, and the housing 1 is generally manufactured to be formed integrally with the housing of the pump.

One end of the spring 60, which provides a force for pushing the spool 50 toward the inlet of the chamber, is installed at the inner end of the chamber and the other end is mounted at one side of the spool 50, and the spool 50 is installed inside the chamber. It is installed to move in a straight line along the axial direction while being in close contact with the. Thus, while the spool 50 is installed to be linearly movable along the axial direction, the connectors 10 and 20 are installed to be fixed to the inlet of the chamber. The connectors 10 and 20 are formed of two members integrally, the front member 10 of the connector is connected to the steering device, and the rear member 20 is integrally fixed to the front member 10. At the same time, the screw portion 21 serves to be fixed to the housing, and the valve 30 is installed therein to adjust the flow rate discharged through the discharge port 11 together with the valve 30.

2 to 8 show the state in which the spool 50 and the connectors 10 and 20 are assembled, and FIG. 2 shows the state when the engine speed N is low. As shown in FIG. 2, the housing 1 has an inflow passage 3 through which pressurized fluid is introduced from the pump and a return passage 2 so that the fluid can be returned to the suction port of the hydraulic pump according to the movement of the spool 50. ) Is formed. In addition, the housing chamber is formed with a second diameter portion into which the spool 50 is fitted and a first diameter portion having a larger diameter than the second diameter portion and into which the connectors 10 and 20 are inserted and fixed, and the spool 50 is The return passage 2 communicates with the second diameter portion, and the inflow passage 3 communicates with the first diameter portions of the connectors 10 and 20. In addition, the spool 50 is inserted into the second diameter part so that the bypass is formed in the housing 1 in communication with the first pressure chamber 6 into which the pressurized fluid flows from the pump and the discharge port 11 discharged from the pump. The second pressure chamber 7 communicates with each other through (4, 5). In addition, the outer surface of the rear member 20 of the connector is formed with a screw portion 21 along the circumferential direction, the screw portion 21 to fix the connector (10, 20) to the housing (1), the first pressure The chamber 6 is divided into an inflow pressure chamber 6a and a discharge pressure chamber 8.

The connectors 10 and 20 are formed so that a fluid passage is formed at the center thereof and fixedly installed at the inlet of the chamber. The front member 10 of the connector is installed to protrude from the housing 1 to the rear of the connector. A fluid flow passage is formed in the center of the member 20, and the valve 30 is installed in the passage through which the fluid flows in a straight line along the axial direction, and the rear end surface of the member 20 allows the valve 30 to be inserted therein. Two slots 26, which are open and slightly spaced apart from each other, about 180 degrees, are formed to face each other, and a hole 23 penetrated between the two slots 26 is formed in the hole 23. The stopper pin 70 is fitted. A second orifice is formed in communication with the first pressure chamber 6 at a distance from the two slots 26.

A screw portion 21 is formed in a cylindrical shape at a predetermined distance away from the front member 10 of the connector.

The two slots 26 and the hole 34 form a first orifice, and the hole 24 communicating with the inlet pressure chamber 6a forms the second orifice together with the hole 36 of the valve. That is, the fluid flowing through the inflow passage 3 is introduced into the fluid passages 31 and 33 of the valve 30 through the first and second orifices. A screw portion 21 fitted into the chamber is formed from the hole 24 of the second orifice, and the hole for allowing the fluid passages 31 and 33 of the connectors 10 and 20 to communicate with the discharge pressure chamber 8 ( 25) is formed.

The valve 30 is inserted into the rear member 20 of the connector and installed to move in a straight line along the axial direction. The front end surface is formed in a cylindrical shape, and the rear end surface has a hole of the first orifice ( The pressurized fluid flowing through the valve 34 is introduced into the fluid passages 31 and 33 inside the valve 30, and the second orifice is connected to the connector at the position where the valve 30 is caught by the stopper pin 70. And an annular groove 35 communicating with the hole 24 of the rear member 20 of the rear member 20 and a hole 36 for communicating the annular groove 35 with the fluid passage 33. As the length of the outer diameter is reduced to form a step, the other end of the spring 40 is caught. As shown in FIG. 8, the third orifice 37 is sealed by the seal of the spring 40 in a state in which the valve 30 is pushed so that the front end surfaces of the valve 30 are caught by the connectors 10 and 20. It is formed to prevent.

It serves to communicate the fluid passage 31 and the discharge pressure chamber (8).

The spool 50 has an annular groove 51 formed on an outer surface thereof, and two holes 52 penetrate at right angles so as to communicate with the inside of the spool 50. When the engine is rotated at low speed, a landing portion 59 is formed in the chamber between the inflow passage 3 and the return passage 2 to seal the space between the inflow passages 3 and the return passages. . A relief valve device is installed in the interior 53 of the spool 50, and, like the conventional relief valve, includes a spring 55, a pusher 54, a ball valve 56, and a plug 57. The oil filter 58 is fitted in the plug 57. That is, if the discharge pressure increases rapidly, the second pressure chamber 7 also rises rapidly accordingly, so that a sudden increase in pressure passes through the central orifice of the plug 57 while compressing the spring 55. By pressing the valve 56 and the pusher 54, the fluid in the second pressure chamber 7 flows through the hole 52 and the annular groove 51 to the return passage 2, thereby controlling the sudden increase in the discharge pressure. To prevent damage to the equipment.

Referring to the operation of the fluid flow control valve according to the present invention configured as described above are as follows. 2 to 8 sequentially show a state that appears as the engine speed N increases.

2 and 3 are cross-sectional views of the control valve in a low speed state with the engine driven, and show the operation in the following areas in the graphs of FIGS. 9 and 10. That is, the total amount of fluid introduced through the inflow passage 3 from the pump is moved to the inlet pressure chamber 6a of the first pressure chamber 6, and then the hole 36 of the first orifice and the valve 30 It flows into the fluid passage 33 through the hole 34 and into the fluid passage 33 through the hole 24, the annular groove 35, and the hole 36 of the second orifice. The fluids are all discharged and moved through the discharge port 11 of the front member 10 of the connector. 3 is a state in which the engine speed N is slightly increased compared to FIG. 2, and the spool 50 is slightly moved inward while overcoming the elastic force of the spring 60 by the pressure of the increased fluid. .

4 is a cross-sectional view showing the state of the control valve in the vicinity of ① in the graphs of FIGS. 9 and 10, in which the fluid flowing into the inlet pressure chamber 6a is discharged through the discharge port 11. 50 is moved further to the inside, and the state immediately before the return passage 2 is opened. Thus, the discharged flow rate gradually increases until this time. Up to this state, as shown in FIG. 10, it can be seen that the cross-sectional area of the orifice through which the fluid passes is kept constant.

5 is a cross-sectional view of the control valve in the state between ① and ② in FIGS. 9 and 10. When the engine speed N is further increased and the pressure of the pressurized fluid flowing from the pump is increased, the spool ( 50) is pushed further into the chamber, and part of the return passage 2 is opened. Of course, the cross-sectional area of the orifice that guides the fluid to the fluid passages 31 and 33 inside the valve 30 is maintained at a constant cross-sectional area as shown in FIG. 10 because the valve 30 is not moved. . Since a part of the return passage 2 is opened and a part of the fluid flowing into the inflow passage 3 is returned to the oil tank through the return passage 2, only the rest other than the fluid discharged to the return passage 2 is returned. It discharges through this discharge port 11, As a result, the discharge volume discharged like the graph shown in FIG. 9 is kept constant. This state represents the maximum value of the discharged flow rate.

6 shows that the engine speed N is further increased to increase the pressure of the fluid flowing through the inflow passage 3, thereby increasing the flow rate returned through the return passage 2, and the valve 30 is spring-loaded. It shows the state which the flow volume which flows in through the 2nd orifice starts to decrease, pushing 40 in the direction of the discharge port 11, compressing. That is, as shown in FIG. 10, the cross-sectional area of the second orifice is reduced, so that the overall orifice cross-sectional area is reduced, and as a result, the discharged flow rate Q is uniformly reduced as shown in FIG. 9. ).

FIG. 7 is a cross-sectional view of a control valve showing a state near the ③ in the graph of FIG. 9, and the flow rate passing through the second orifice becomes zero because the valve 30 is further moved by pressure and the second orifice is closed. It can be seen that only the hole 34 of the first orifice starts to flow the fluid, and the spool 50 also moves inward to increase the return flow rate. In this state, when the engine speed N increases, the valve 30 moves further forward as shown in FIG. 8, and the flow rate through the second orifice becomes zero as in the state of FIG. 7 and all discharge flow rates. Passes through only the first orifice 34. In addition, as shown in FIG. 10, the cross-sectional area of the orifice flowing into the fluid passage 33 is maintained to be the same as the cross-sectional area of the first orifice.

In this way, the fluid flow control valve according to the present invention is installed so that the valve formed in a simple shape is caught by the stopper pin, and is formed to have a hole communicating with the first and second orifices therein. 2 Controls the flow of fluid by adjusting the flow rate flowing through the orifice.

The present invention is not limited to the above embodiments and may be variously modified and implemented by those skilled in the art without departing from the technical gist of the present invention.

Claims (3)

The housing is provided with an inflow passage through which pressurized fluid flows from a pump, a return passage through which a part of the pressurized fluid returns to the oil tank, and a chamber open at one end so that various parts are installed and connected to the inflow passage and the return passage. And a spool installed to be inserted into the chamber of the housing so as to be linearly driven according to the pressure of the pressurized fluid flowing into the inflow passage, thereby opening or closing the return passage and dividing the chamber into a first pressure chamber on the inflow passage side and a second pressure chamber on the rear side. And a spring provided at one end to the spool and the other end to the chamber of the housing to provide an elastic force for pushing the spool outward of the chamber, and fixed to the inlet of the chamber and having a fluid passage therein. A first orifice and a second orifice are formed to communicate with each other through the fluid passage, and the first pressure chamber is introduced into the inflow passage. A connector formed to be divided into a discharge pressure chamber communicating with the second pressure chamber through a bypass passage formed in the inlet pressure chamber on the side of the housing and having a fluid passage communicating with the discharge pressure chamber, and an axial direction inside the connector; And a fluid passage formed therein to be linearly movable and having a fluid passage therein for forming a fluid passage of the connector, and a passage for communicating the fluid passage to the first and second orifices of the connector, respectively. A valve formed to reduce the area of the passage communicating with the second orifice, a spring that is provided to be caught by the inside of the connector and the other end by the valve to provide an elastic force to push the valve in a direction opposite to the hydraulic pressure; At the rear of the connector while the valve is assembled to prevent separation of the valve. Fluid flow control valve, comprising a step of including a stopper pin is installed fitted with both ends of the generated holes. The method of claim 1, The valve is formed in a cylindrical shape with the front open, the connector is installed to be movable along the axial direction, the front end is formed with a step to reduce the outer diameter of a predetermined length, the spring pushing the valve to the step It is formed to take one end of, the rear end is formed with a hole in communication with the fluid passage of the connector, the outer diameter of the center is formed with an annular groove and a hole in communication with the annular groove and the fluid passage so as to communicate with the fluid passage Fluid flow control valve. delete

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