OIL CONTROL VALVE

Abstract

As an oil control valve controlling oil pressure of a first hydraulic pressure chamber and a second hydraulic pressure chamber formed inside of a first electric hydraulic valve (EHV) device and a second EHV device, respectively, which are driven by a first cam and a second cam and include lower parts to which a first valve and a second valve are respectively connected, the oil control valve includes: a body including a communication hole having a first end in communication with the first hydraulic pressure chamber and a second end in communication with the second hydraulic pressure chamber; a hollow lower frame formed or fixedly mounted at the lower end part of the body and having an upper part communicating with the communication hole and a lower part communicating with an oil gallery supplying oil by disposing an upper end height at an inner space of the communication hole; and a pin frame disposed between an actuator moving up and down and the lower frame so as to vertically penetrate the communication hole and in contact with or separated from the upper part of the lower frame, wherein one end and the other end of the communication hole are in communication when the pin frame and the lower frame are in contact.

Description

CROSS REFERENCE TO RELATED APPLICATION

This application claims priority to and the benefit of Korean Patent Application No. 10-2018-0159341 filed in the Korean Intellectual Property Office on Dec. 11, 2018, the entire contents of which are incorporated herein by reference.

BACKGROUND

(a) Field of Disclosure

The present disclosure relates to an oil control valve (OCV). More particularly, the present disclosure relates to an oil control valve that prevents an occurrence of lift deviations between two valves of the same type.

(b) Description of the Related Art

A variable valve control technology is one field for improving efficiency of automobile engines.

Generally, intake and exhaust of an engine are controlled by adjusting opening and closing timing of valves by a shape of a cam and a phase difference between the cams.

A variable valve timing (VVT) means adjusts the opening and closing timing of the valves to control an overlap section in which an intake valve and an exhaust valve are simultaneously open, and a variable valve lift (VVL) means adjusts a valve lift to control an intake air amount.

As the VVT means evolved into a continuous variable valve timing (CVVT) means, the VVL means evolved into a continuous variable valve lift (CVVL) means, and a mechanical electric hydraulic valve train (MEHV) means has been developed and actively applied to a vehicle engine.

The MEHV means is a combination of a mechanical valve mechanism and an electric hydraulic valve (EHV), and controls the valve lift by using oil pressure.

Generally, the MEHV system operates two electric hydraulic valve (EHV) devices having the same structure, and two valves of the same type (intake or exhaust) respectively connected to the above-described devices by using one oil control valve (OCV).

The EHV device is generally driven by a mechanical cam, and a hydraulic pressure chamber is formed in the EHV device, and as the oil is supplied to the hydraulic pressure chamber through the OCV or the oil is discharged from the hydraulic pressure chamber, the driving effect by the cam is controlled. That is, if the cam drives the EHV device in the state in which sufficient oil is supplied to the EHV device, the valve connected to the EHV device operates, resulting in the valve lift. However, if the cam drives the EHV device in a state in which the oil is drained from the EHV device, the valves connected to the EHV device do not work.

The conventional MEHV systems use the OCV configured to allow two EHV devices to communicate with each other for smooth supply of the oil. Therefore, when there is an oil pressure difference between the two EHV devices, oil pulsation may occur between the two EHV devices, and as a result, a lift deviation occurs between the two valves respectively connected to two EHV devices.

FIG. 5 is a graph showing a valve lift according to a cam angle when a conventional oil control valve is applied.

Referring to FIG. 5, the lift deviation appears between the left and right valves. In this state, an imbalance of combustions of the engine cylinders may occur, and the fuel consumption, emission, or knocking characteristics may deteriorate.

The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.

SUMMARY

The present disclosure provides an oil control valve for preventing a lift deviation between two valves.

An oil control valve controlling oil pressure of a first hydraulic pressure chamber and a second hydraulic pressure chamber formed inside of a first electric hydraulic valve (EHV) device and a second EHV device, respectively, which are driven by a first cam and a second cam and include lower parts to which a first valve and a second valve are respectively connected, may include a body including a communication hole having a first end in communication with the first hydraulic pressure chamber and a second end in communication with the second hydraulic pressure chamber; a hollow lower frame formed or fixedly mounted at the lower end part of the body and having an upper part communicating with the communication hole and a lower part communicating with an oil gallery supplying oil by disposing an upper end height at an inner space of the communication hole; and a pin frame disposed between an actuator moving up and down and the hollow lower frame so as to vertically penetrate the communication hole and in contact with or separated from the upper part of the lower frame, wherein each end of the communication hole are not communicated when the pin frame and the hollow lower frame are in contact.

The pin frame may be hollow, and the oil control valve may further include a spring acting as a restoring force to the pin frame as the upper end is connected to the upper part of the pin frame and the lower end is connected to a supporting part formed at an inner space of the lower frame.

The actuator may be operated up and down by a solenoid.

The pin frame may be integrally formed with the lower end part of the actuator.

The lower frame, the communication hole, and the pin frame may each have a cylinder shape, and a diameter of the lower frame and the pin frame may be larger than a diameter of the communication hole.

A chamfer may be formed along an external circumference surface of the lower end of the pin frame in the pin frame, and a chamfer surface may be formed at the upper end of the lower frame so as to maintain a fixed and air-tight state by meeting the chamfer.

In the oil control valve according to an exemplary embodiment of the present disclosure, when the pin frame is separated from the lower frame, as the oil is drained from the first EHV device and the second EHV device, the first valve and the second valve may not be operated despite the operation of the first cam and the second cam.

In the oil control valve, when the pin frame is in contact with the lower frame, the first valve and the second valve may be operated by the operation of the first cam and the second cam.

As described above, according to the present disclosure, since the lift profiles between the two valves are equal to each other, the fuel efficiency and the emission may be improved, and the occurrence of knocking may be reduced.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a schematic diagram of a valve train structure mounted with an oil control valve according to an exemplary embodiment of the present disclosure.

FIG. 2 is a side view of a valve train structure mounted with an oil control valve according to an exemplary embodiment of the present disclosure.

FIG. 3 is a cross-sectional view along a line A-A of an oil control valve according to an exemplary embodiment of the present disclosure.

FIG. 4 is a cross-sectional view along a line B-B of an oil control valve according to an exemplary embodiment of the present disclosure.

FIG. 5 is a graph showing a valve lift according to a cam angle when a conventional oil control valve is applied.

FIG. 6 is a graph showing a valve lift according to a cam angle when an oil control valve according to an exemplary embodiment of the present disclosure.

DETAILED DESCRIPTION

The present disclosure will be described more fully hereinafter with reference to the accompanying drawings, in which an exemplary embodiment of the disclosure is shown.

The exemplary embodiment is an example of the present disclosure and can be modified in various ways by those skilled in the art, so the scope of the present disclosure is not limited to the exemplary embodiment to be described below.

Through the present specification, unless explicitly described otherwise, “including” any components will be understood to imply the inclusion of other components but not the exclusion of any other components. Further, the names of the components do not limit their function.

FIG. 1 is a schematic diagram of a valve train structure mounted with an oil control valve according to an exemplary embodiment of the present disclosure.

FIG. 2 is a side view of a valve train structure mounted with an oil control valve according to an exemplary embodiment of the present disclosure.

Referring to FIG. 1 and FIG. 2, an oil control valve 10 according to an exemplary embodiment is configured to control oil pressure of a first hydraulic pressure chamber 21a and a second hydraulic pressure chamber 22a formed inside of a first electric hydraulic valve (EHV) device 21 and a second EHV device 22, respectively. The first EHV device 21 and the second EHV device 22 are driven by a first cam 1 and a second cam 2, respectively, and a first valve 3 and a second valve 4 are connected to the lower parts thereof, respectively. Therefore, the operation of the first valve 3 and the second valve 4 is controlled by the oil control valve 10.

The oil control valve 10 may include a body 30 having a communication hole 312 including a first end 31 communicating with the first hydraulic pressure chamber 21a and a second end 32 communicating with the second hydraulic pressure chamber 22a. The body 30 further includes a hollow lower frame 40 formed or fixedly mounted at the lower end part of the body 30, and having an upper part communicating with the communication hole 312. A lower part of the body 30 communicates with an oil gallery 34 supplying oil by disposing an upper end height at an inner space of the communication hole 312. A pin frame 50 is disposed between an actuator 15 moving up and down and the lower frame 40 so as to vertically penetrate the communication hole 312 and in contact with or separated from the upper end of the lower frame 40.

The oil control valve 10 is configured so that the first and second ends 31, 32 of the communication hole 312 do not communicate with each other when the pin frame 50 and the lower frame 40 are in contact with each other. That is, the ends are blocked by the lower frame 40 and the pin frame 50.

To this end, the lower frame 40, the communication hole 312, and the pin frame 50 may have a cylinder shape, and the lower frame 40 and the pin frame 50 may have a greater diameter than the diameter of the communication hole 312. However, the exemplary embodiment is not limited thereto, and in the contact between the lower frame 40 and the pin frame 50, as long as the lower frame 40 and the pin frame 50 block the inside of the communication hole 312 so that the first and second ends 31, 32 of the communication hole do not communicate with each other, any structure is allowed.

The first hydraulic pressure chamber 21a and the first end 31 of the communication hole 312 may communicate by way of a left pipe 5 and the second hydraulic pressure chamber 22a, and the second end 32 of the communication hole 312 may be communicated by way of a right pipe 6. In this case, the left and right pipes 5 and 6 may be formed in a cylinder head 7. The oil control valve 10 is typically mounted on the cylinder head 7.

The mechanism by which the first and second hydraulic pressure chambers 21a and 22 as are formed in the first and second EHV devices 21 and 22, respectively, are well known to those skilled in the art and thus the detailed description is omitted.

When the pin frame 50 is separated from the upper end of the lower frame 40, the first and second EHV devices 21 and 22 may communicate with each other through the first and second hydraulic pressure chambers 21a and 22a, the right and left pipes 5 and 6, and the communication hole 312.

Also, referring to FIG. 2, the valve train structure mounted with the oil control valve 10 according to an exemplary embodiment may further include an accumulator 25 formed in the cylinder head 7. In this case, when the oil control valve 10 is open, that is, when the pin frame 50 is separated from the lower frame 40, the valve train structure may be formed so that the oil in the first and second EHV devices 21 and 22 may be accumulated in the accumulator 25. By the oil flow to the accumulator 25, the first and second valves 3 and 4 are closed despite the actions of the first and second cams 1 and 2.

Referring to FIG. 1, in the oil control valve 10 according to an exemplary embodiment, the pin frame 50 may be hollow. Also, the oil control valve 10, as the upper end is connected to the upper part of the pin frame 50 and the lower end is connected to a supporting part 35 formed in the inner space of the lower frame 40, may further include a spring 60 acting as a restoring force to the pin frame 50.

The actuator 15, which is disposed within the oil control valve 10, may be operated up and down by the solenoid. In this case, when the current is applied to the oil control valve 10, the actuator 15 is operated up or down.

Thus, when the actuator 15 is operated downward and the pin frame 50 is in contact with the lower frame 40, the spring 60 may be compressed, and when the actuator 15 is actuated upward so that the pin frame 50 is separated from the lower frame 40, the spring 60 may be extended. When the current applied to the oil control valve 10 is disconnected, the pin frame 50 may be returned to its initial position by the restoring force of the compressed or extended spring 60.

The pin frame 50 may be integrally formed with the lower end of the actuator 15, but it is not necessarily so. The pin frame 50 may be a part that is separate from the actuator 15. The pin frame 50 may be selectively in contact with or separated from the lower frame 40 by the actuator 15 and the spring 60.

FIG. 3 is a cross-sectional view of along a line A-A of an oil control valve according to an exemplary embodiment of the present disclosure.

FIG. 4 is a cross-sectional view of along a line B-B of an oil control valve according to an exemplary embodiment of the present disclosure.

Referring to FIG. 3 and FIG. 4, in the oil control valve 10 according to an exemplary embodiment of the present disclosure, a chamfer 52 may be formed along an external circumference surface of the lower end of the pin frame 50 in the pin frame 50, and a chamfer surface 42 may be formed at the upper end of the lower frame 40 so as to maintain the fixed and air-tight condition by meeting the chamfer 52. The combination of the chamfer 52 and the chamfer surface 42 may ensure completion of the fixing state of the pin frame 50 and the lower frame 40 and the air-tight state between the first end 31 and the second end 32 of the communication hole 312.

FIG. 3 and FIG. 4 both show the state in which the lower frame 40 and the pin frame 50 are separated from each other. The oil may be supplied to the first and second EHV devices 21 and 22 through this separation gap and the communication hole 312, or the oil may be drained from the first and second EHV devices 21 and 22 to the accumulator 25.

Referring to FIG. 1, FIG. 3, and FIG. 4, the oil control valve 10 according to an exemplary embodiment of the present disclosure is configured so that the first valve 3 and the second valve 4 are not operated despite the operation of the first cam 1 and the second cam 2 as the oil is drained from the first EHV device 21 and the second EHV device 22 when the pin frame 50 is separated from the lower frame 40.

The oil control valve 10 is configured so that the first valve 3 and the second valve 4 are operated by the operation of the first cam 1 and the second cam 2 when the pin frame 50 is in contact with the lower frame 40.

FIG. 6 is a graph showing a valve lift according to a cam angle when an oil control valve according to an exemplary embodiment of the present disclosure.

Referring to FIG. 6, if the oil control valve 10 is used, it may be confirmed that the lift of the first and second valves 3 and 4 is substantially coincident. This is because the first and second EHV devices 21 and 22 communicate with each other when the communication hole 312 is not blocked by the lower frame 40 and the pin frame 50 such that the pressure becomes equal, and the first and second EHV devices 21 and 22 are fluidly separated from each other and operate independently at the same pressure in case of the blocking.

While this disclosure has been described in connection with what is presently considered to be practical exemplary embodiments, it is to be understood that the disclosure is not limited to the disclosed embodiments. On the contrary, it is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims.

Claims

1. An oil control valve controlling oil pressure of a first hydraulic pressure chamber and a second hydraulic pressure chamber formed inside of a first electric hydraulic valve (EHV) device and a second EHV device, respectively, which are driven by a first cam and a second cam and include lower parts to which a first valve and a second valve are respectively connected, comprising: a body including a communication hole having a first end in communication with the first hydraulic pressure chamber and a second end in communication with the second hydraulic pressure chamber;a hollow lower frame formed or fixedly mounted at a lower end part of the body, the hollow lower frame having an upper part communicating with the communication hole and a lower part communicating with an oil gallery supplying oil by disposing an upper end height at an inner space of the communication hole; anda pin frame disposed between an actuator moving up and down and the hollow lower frame so as to vertically penetrate the communication hole and in contact with or separated from the upper part of the hollow lower frame,wherein the first end and the second end of the communication hole are not communicated with each other when the pin frame and the hollow lower frame are in contact with each other.

2. The oil control valve of claim 1, wherein the pin frame is hollow, andthe oil control valve further includes a spring acting as a restoring force to the pin frame as the upper end is connected to an upper part of the pin frame and the lower end is connected to a supporting part formed at an inner space of the hollow lower frame.

3. The oil control valve of claim 1, wherein the actuator is operated up and down by a solenoid.

4. The oil control valve of claim 1, wherein the pin frame is integrally formed with the lower end part of the actuator.

5. The oil control valve of claim 1, wherein the hollow lower frame, the communication hole, and the pin frame each have a cylinder shape, and a diameter of the hollow lower frame and the pin frame is larger than a diameter of the communication hole.

6. The oil control valve of claim 1, wherein a chamfer is formed along an external circumference surface of a lower end of the pin frame in the pin frame, anda chamfer surface is formed at the upper end of the lower frame so as to maintain a fixed and air-tight state by meeting the chamfer.

7. The oil control valve of claim 1, wherein when the pin frame is separated from the lower frame, as the oil is drained from the first EHV device and the second EHV device, the first valve and the second valve are not operated despite the operation of the first cam and the second cam.

8. The oil control valve of claim 1, wherein when the pin frame is in contact with the hollow lower frame, the first valve and the second valve are operated by the operation of the first cam and the second cam.