KR100213156B1 - Intake valve open / close variable device of internal combustion engine - Google Patents

Abstract

In order to control the lift and open time of the intake valve according to the speed range of the engine to obtain high torque at medium to low speed and to improve the output at high speed, the cylinder head having a plurality of slits and the slits are independently located First, second, third, and fourth rocker arm shafts, which are completed with springs, rocker arms installed on the arm shafts, each having a low speed roller and a high speed roller at both ends thereof; And an intake cam shaft and a variable cam shaft which are in contact with the roller and cause displacement of the rocker arm. The rocker arm has a pressurization passage formed therein, and the pressurization passage has a chamber in which the piston having the medium and low speed roller is installed. And a passage communicating with the pressure passage through the rocker arm shaft, the pressure generated from the oil pump. And so as to supply or discharge the working provides a variable intake valve opening and closing apparatus of an internal combustion engine as specified that is configured to vary the hinge point of the rocker arm.

Description

Intake valve open / close variable device of internal combustion engine

Figure 1 is an exploded perspective view of the intake valve opening and closing variable apparatus according to the present invention.

2 is a side cross-sectional view of the variable means according to the present invention.

3 is a view for explaining a power transmission system of the intake valve opening and closing variable apparatus according to the present invention.

4 is a view for explaining the operation of the variable opening and closing apparatus according to the present invention.

5 is a view showing a valve lift curve of the opening and closing variable apparatus according to the present invention,

a is a diagram at low and medium speed,

b is a diagram of high speed.

6 is a view for explaining a valve lift curve by the conventional valve opening and closing device.

* Explanation of symbols for main parts of the drawings

2: cylinder head 4: intake valve

8: rocker arm 10, 12, 14, 16: rocker arm axis

18, 20, 22, 24: Slits 26, 38: Spring

28: passage 32: pressure passage

34: chamber 36: piston

40: medium and low speed roller 42: high speed roller

44: medium and low speed cam 46: high speed cam

The present invention relates to an intake valve opening / closing variable device of an internal combustion engine, and more particularly, to change the displacement of the intake side cam according to the speed range of the engine to obtain high torque at low and medium speeds, and to improve output at high speed. One intake valve opening and closing variable device.

In general, high-performance engines seek to change intake cylinders to increase intake efficiency and to change the intake flow state appropriately according to the engine state.

The precise opening and closing of the valve in accordance with the rotation of the crankshaft is called the valve opening and closing time. The opening and closing of the valve causes suction and compression of the mixer and discharge of the combustion gas.

The intake valve is opened immediately before the intake stroke of the piston, that is, the exhaust stroke, and closes after the bottom dead center of the intake stroke, thereby adjusting the valve opening and closing time.

This is to inject the mixer into the combustion chamber as much as possible by using the inertia of the intake air. For this purpose, there is an overlap period in which both the intake valve and the exhaust valve are open.

However, since there is a limit in increasing the inertia of the intake in this manner, a so-called variable valve system has been proposed that varies the opening and closing timing of the valve according to the speed range of the engine.

In terms of engine performance in general, the smaller the overlap section, the better. That is, in FIG. 6, it is preferable to reduce the area of the section C so that the closing point V1 of the exhaust valve is after the opening point V2 of the intake valve.

At low and medium speeds, the speed of intake is not fast, so the closing point (V3) of the intake valve must be fast so that new air sucked out does not go out again, and at high speed, the closing point (V3) of the intake valve is high. The later it closes to the limit, the better the suction efficiency.

Since these conditions cannot be satisfied in one fixed cam profile, if you design for high torque at low and medium speeds, you cannot expect high output in the high speed range, and if you design for maximum output in the high speed range, At low medium speeds, the torque is reduced.

In order to satisfy all these conditions, it is necessary to change the opening and closing timing and timing of the valve according to the speed range of the engine.

The present invention has been invented to solve the problems of the prior art as described above, an object of the present invention is to provide a variable valve opening and closing device that can vary the opening and closing time of the intake valve and the head of the valve in accordance with the engine speed range. It is.

In order to realize the object of the present invention as described above, the cylinder head having a plurality of slits, the first, second, third, fourth rocker arm shafts each independently positioned in the slit and supported by a spring, Rocker arms installed on the arm shafts, each having a low and low speed roller and a high speed roller at both ends thereof, and an intake cam shaft and a variable cam shaft in contact with the medium and low speed roller and the high speed roller to cause displacement of the rocker arm. The rocker arm is formed with a pressurized passage, and the pressurized passage is formed with a chamber in which the piston with the medium and low speed rollers is installed, and the rocker arm shaft has a passage communicating with the pressurized passage. To change the hinge point of the rocker arm by supplying or releasing pressure oil from the oil pump. It provides a variable intake valve opening and closing apparatus for an internal combustion engine, characterized in that that generated.

The piston in the chamber provides an intake valve opening and closing device of the internal combustion engine, characterized in that the spring is supported by a spring.

The rocker arm provides an intake valve opening and closing device of an internal combustion engine, characterized in that the rocker arm axis is varied at the center of rotation at low and medium speeds.

In addition, the rocker arm provides a variable intake valve opening and closing device of the internal combustion engine, characterized in that rotated around the point of contact between the medium and low speed roller and the medium and low speed cam at high speed.

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

1 is a view showing a state in which the valve opening and closing variable apparatus according to the present invention is installed in the cylinder head, reference numeral 2 designates a cylinder head.

The cylinder head 2 is provided with a plurality of intake valves 4 and exhaust valves 6 so as to open and close according to the rotational action of the rocker arm 8.

The rocker arm 8 described above is fitted to the rotor arm shaft, and the rocker arm of the present invention has a divided structure.

That is, it is divided into a first rocker arm shaft 10, a second rocker arm shaft 12, a third rocker arm shaft 14, a fourth rocker arm shaft 16, and the like.

And the respective rocker arms 8 are fitted to each of these rocker arm shafts, and these first, second, third and fourth rocker arm shafts 10, 12, 14, 16 are respectively mounted on the cylinder head 2; The slots 18, 20, 22, and 24 are formed to be liftable.

Therefore, these slits have the shape of a long hole that is formed long in the vertical direction, the springs 26 that elastically support the rocker arm axis is provided inward.

The rocker arm axes 10, 12, 14, 16 are fitted in the central portion of the rocker arm 8, which are upper side by a spring 26 located in a slit 18 formed in the cylinder head 2. It is supported in an elastic force.

The rocker arm shafts are configured such that oil passaged from an oil pump (not shown) may be introduced through the passage 28 in the longitudinal direction.

As such, the means by which the engine oil can be guided through the passage of the rocker arm shaft can be used as a conventional means used in the valve opening and closing variable stage, and thus, detailed description thereof is omitted.

The passage 28 of the first rocker arm shaft 10 has a coupling relationship capable of supplying oil to the pressure passage 32 formed in the rocker arm 8 through a bypass passage 30 drilled laterally. Is done.

A chamber 34 is formed above the end of the pressure passage 32 so that the piston 36 can be lifted up and down into the chamber.

The piston 36 is installed in a state where it is supported by the spring 38 and always receives an elastic force upward.

The piston 36 is provided with a middle low speed roller 40 so as to be rotated, and a high speed roller 42 is rotatably installed at a side opposite to the medium low speed roller 40.

The medium and low speed roller 40 is installed while maintaining contact with the medium and low speed cam 44, and the high speed roller 42 is installed while maintaining contact with the high speed cam 46.

The medium and low speed cam 44 and the high speed cam 46 are electrically driven by the intake cam shaft 48 provided with the high speed cam 46 and the intake cam shaft and the belt or chain, as shown in FIG. It is installed on the variable cam shaft 50 installed as possible so as to receive the rotational force of the crank shaft 52.

In the intake valve opening and closing variable device of the present invention, the driving force rotates the crank shaft 52 when the engine is driven, thereby allowing the intake cam shaft 48 and the exhaust cam shaft 49 to be driven through the timing belt V. Will rotate.

In this case, when the speed range of the engine is a low to medium speed section, the oil supplied to the passage 28 of the rocker arm shaft 10 is blocked.

This supply of oil can be achieved by installing a solenoid valve on the passageway leading to the passage 28 and allowing the solenoid valve to be controlled by the electronic control unit (ECU) on and off. The description is omitted.

If the oil is not supplied to the passage 28 of the rocker arm shaft 10 by the above-described action, the medium to low speed roller 40 installed on the rocker arm 8 is the portion of the spring 38 that pushes the piston 36 upwards. The state is supported only by the elastic force.

Therefore, when the intake cam shaft 48 is rotated, the high speed cam 46 rotates while maintaining the contact state with the high speed roller 42, and the medium and low speed cam 44 is in contact with the medium and low speed roller 40. The low and medium speed roller 40 is absorbed by the rotation of the cam while the spring 38 is compressed, so that the medium and low speed roller 40 has no influence on the rocker arm 8 in this state.

Therefore, when the rocker arm 8 rotates about the rocker arm shaft 10, the opening and closing action of the intake valve 4 is achieved only by the cam follower of the high speed cam 46.

This opening and closing action is the same as the general valve opening and closing action, when the engine enters the high speed region, the engine oil is supplied into the passage 28 of the rocker arm shaft 10 via the bypass passage 30 and the rocker arm 8 It is supplied to the pressure passage 32 formed in the).

Since the pressure passage 32 communicates with the chamber 34, the piston 36 is in a state of receiving upward force by the pressure of oil flowing there.

In this state, even when the low speed cam 44 rotates, the piston 36 cannot be lowered by the pressure of the oil, so the center of rotation of the rocker arm 8 is changed by the low speed cam 44.

That is, the rocker arm shaft 10 became the pivot center of the rocker arm 8 at the medium and low speeds, and at the high speed, the portion where the medium and low speed cams 44 and the medium and low rollers 40 contacted each other was the pivot center of the rocker arm 8. Becomes

When this point becomes the pivot center of the rocker arm 8, the rocker arm 8 pressed by the high speed cam 46 must move downward with the rocker arm axis 10.

The movement of the rocker arm shaft 10 and the rocker arm 8 is possible because the rocker arm shaft 10 is supported by the spring 26 in the slit 24 formed in the cylinder head 2.

In other words, as shown in Fig. 4 a), the rocker arm 8 rotates around the point A at low and medium speeds, and the rocker arm 8 rotates around the point B at high speed.

Due to this action, the head of the intake valve 4 at the low and medium speeds corresponds to L1 as shown in FIG. 5 a), but at high speed, L2 is larger than the head L1 as shown in FIG. 5 b) at high speed. Intake valve is opened and closed by lifting head.

The opening and closing action of the intake valve thus not only changes the lift of the valve but also relates to the opening and closing timing of the valve.

That is, in the medium and low speed, as shown in FIG. 5 a) and b), the opening point V2 of the intake valve is later than that of the high speed ash, so that the opening operation of the intake valve is performed rapidly at substantially high speed. .

By this action, the overlap section (C) is smaller than the high speed at the middle low speed to improve the filling efficiency of the intake, it can be seen that the closing point (V3) of the intake valve is faster than the high speed at the medium low speed.

Therefore, the valve opening variable device according to the present invention can vary the lift curve of the valve by varying the pivoting point of the rocker arm to obtain a quiet engine characteristic at idle, high torque at low and medium speeds, and at high speed. High output can be obtained.

Claims (4)

A cylinder head having a plurality of slits, first, second, third and fourth rocker arm shafts each independently positioned in the slit and supported by a spring, and installed on the arm shafts and having a low and low speed roller at both ends, And a rocker arm having a high speed roller, an intake cam shaft and a variable cam shaft in contact with the medium and low speed rollers and the high speed roller to cause displacement of the rocker arm, and the rocker arm is formed with a pressure passage. In addition, the pressure passage is formed with a chamber in which the piston with the medium and low speed rollers is installed, and the rocker arm shaft is provided with a passage communicating with the pressure passage to supply or discharge the pressure oil generated from the oil pump. The intake valve opening and closing device of the internal combustion board, characterized in that configured to vary the hinge point of the rocker arm. The intake valve opening and closing device of an internal combustion engine according to claim 1, wherein the piston in the chamber is supported by a spring. 2. The intake valve opening and closing device of the internal combustion substrate according to claim 1, wherein the rocker arm is variable at the center of gravity at the rocker arm axis. The intake valve opening and closing device of an internal combustion engine according to claim 1, wherein the rocker arm is rotated around a point where the medium to low speed roller and the medium to low speed cam contact each other at a high speed.