KR970000749B1 - Intake & exhaust valve variable driving apparatus for a car - Google Patents

Abstract

The variable switching device for air inlet/outlet valve for use in automobile comprises: a cam shaft(1) having a helical-shaped spline groove(4) and a helical gear(3) which is toothing-connected to each other, on the one side end thereof; a flange(5) extended from the helical gear(3); a moving core(8) positioned on the hollow portion of the inside of an extended portion(9) of the cam shaft(1), the moving core being connected with the flange via a connection rod(6); a piston(12) having a path(11) on which a left hydraulic chamber(13) and a right hydraulic chamber(14) are installed, respectively; first and second balls(21,22) elastically supported by second elastic members(23, 24); first elastic members(17,18) for supporting sheets(19,20) by which the second elastic members(23,24) are supported; and a direction switching valve(27) engaged in accordance with the driving of solenoid valves(34,35) controlled by ECU and connected with the oil hole(25), thus to selectively flow a high or low pressure of fluid therefrom.

Description

Variable Inlet / Outlet Valve for Automobile

1 is a side cross-sectional view of the inlet and outlet valve variable switching device according to the present invention.

2 is a plan view showing a displacement groove of a Kim axis according to the present invention.

3 is a side cross-sectional view showing an operating state of the intake / exhaust valve variable switching device according to the present invention.

* Explanation of symbols for main parts of the drawings

1: Camshaft 3: Helical Gear

5: flange 6: connecting rod

7: Variable Mechanism 8: Moving Core

10 inward flange 11 passage

12: piston 13: left hydraulic chamber

14: right hydraulic chamber 17, 18: the first elastic member

19,20: Sheet 21,22: Ball

23,24: second elastic member 25: oil hole

26: control unit 27: directional control valve

34,35: Solenoid Valve

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a variable opening and closing device for automobile intake and exhaust valves, and more particularly, to a variable intake and valve valve opening and closing that can adjust the valve opening and closing timing optimally by continuously changing the phase of a camshaft.

Automotive intake and exhaust valves are connected to the crankshaft and the chain or the timing belt and linked to the camshaft to rotate together to open and close the operation.

In order to improve the output of the engine, it is necessary to set the opening / closing speed or air speed of the valve to increase the opening area of the valve and to draw a large amount of air into the cylinder. However, if the valve speed or acceleration is too fast, the valve collides with the valve seat. In addition, since the movement of the valve is not related to the trajectory of the cam, the noise increases and causes the valve to break.

The intake valve is opened just before the intake stroke of the piston, i.e., the exhaust stroke, and closes past the bottom dead center of the intake stroke.

This takes advantage of the large amount of air drawn into the combustion chamber using the inertia of the intake air.

The exhaust valve is opened before the power stroke is completed, that is, before the bottom dead center, so that the combustion gas is quickly discharged out of the cylinder.

In most cases, the camshaft is rotated once when the crankshaft rotates in two revolutions. However, since the cam directly related to opening and closing of the intake and exhaust valves has a fixed position on the camshaft, the valve opening and closing timing is invariable.

Such an intake / exhaust valve opening and closing device may have an optimum opening and closing time in a specific rotational speed region, but is not preferable in fuel economy and output since it may not have an optimal opening and closing time in the full rotational speed region of the engine.

The invention has been invented to solve the problems of the prior art as described above, the object of the present invention is to change the opening and closing time of the valve in the full speed range of the engine to improve the high power and fuel economy, An exhaust valve variable switching device is provided.

Adjusting the opening and closing timing of the intake and exhaust valves is realized by continuously changing the phase of the camshaft. A position control mechanism related to the camshaft is provided to be movable in the axial direction so that the camshaft phase can be changed by the movement of the position control mechanism. Doing.

To this end, the present invention, the spline coupled to the helical gear that receives power from the crankshaft to one end of the camshaft, connecting the flange of the helical gear and the moving core of the variable mechanism with a connecting rod to enable movement together with this movement The sheets which are supported by the low and first elastic members are installed in the left and right hydraulic chambers formed on the left and right sides of the inward flange of the core, and the balls are installed on both ends of the passages drilled in the center of the inward flange. Provided is a variable opening and closing device for an intake and exhaust valve for a vehicle, which is pushed out by a movement of a piston, and the passage is in communication with a directional valve operated by a solenoid valve controlled by an ECU.

1 is a side cross-sectional view of a variable opening and closing device of the intake / exhaust valve according to the present invention, in which a spline shaft 2 is integrally formed at one end of the cam shaft 1 and a helical gear is formed to allow movement in the axial direction. 3) is installed so that the rotation in the circumferential direction is made together.

The helical gear 3 is a gear that is connected to the crankshaft by a chain or a timing belt to transmit power, and the connecting rod 6 is fixed to the flange 5 extending from the spline groove 4 so that the connection rod 6 is fixed inwardly. The tip end of the rod 6 is connected to the moving core 8 of the variable mechanism 97.

The movable core 8 is located on the inner hollow portion formed in the extension 9 of the camshaft 1, and on the passage 11 penetrating the inward flange 10 formed in the central portion of the movable core 8. The piston 12 is positioned to separate the left hydraulic chamber 13 and the right hydraulic chamber 14.

Each of the plungers 15 and 16 is provided in the left and right hydraulic chambers 13 and 14, and the first elastic members 17 and 18 are located inside the plungers 15 and 16, respectively. A force for bringing the sheets 19 and 20 into close contact with the inward flange 10 is applied.

Balls 21 and 22 are positioned at both ends of the passage 11, respectively, and are elastically installed with the second elastic members 23 and 24, and the outer portions of the second elastic members 23 and 24 are provided. Is supported by the sheets 19 and 2 so that the moving force of the balls 21 and 22 can be accommodated.

The tip of the extension portion 9 of the camshaft 1 is to limit the movement of the plunger 16 is coupled to the cap (C), the outer circumference to rotate through the bearing (B) in the cylinder head (H) It is supported so that.

The oil hole 25 is drilled through the cylinder head H, and is connected to the direction change valve 27 of the controller 26.

The oil hole 25 connected to the directional valve 27 is connected to both ends of the piston 12 located in the passage 11 via the bearing B, the extension 9, and the inward flange 10. It is supposed to work.

The directional valve 27 has one low compression port 28 and two high pressure side ports 29 and 30, and ports 31 and 32 connected to oil holes 25, respectively. Holds.

The valve spool 33, which is located inside the directional valve 27 and moves, has a solenoid valve 34 which is connected to an ECU having both ends connected to an ECU that detects an engine load and rotational speed and outputs an electrical signal. 35) and mechanically connected.

2 is a view showing the relationship between the extension portion 9 of the camshaft and the connecting rod 6 according to the present invention. An inclined hole 36 is drilled through the extension portion 9, and the hole is connected to the connecting rod ( 6) is penetrated to absorb the phase difference generated between the helical gear (3) and the spline (4) which is geared to allow the rotary core and the linear movement in the movement of the moving core (8).

In the intake / exhaust valve variable opening and closing device of the present invention, the hydraulic pressure is transmitted to the low pressure side ports 29 and 30 in the state where the spool 33 is moved to the neutral position as shown in FIG. Since both ends of the piston 12 are supplied at the same pressure through the 31 and 32, the moving core 8 remains neutral without moving.

The control of the control unit 26 is performed by the control of the ECU. When the solenoid valve 34 acts to move the valve spool 33 to the left as shown in FIG. 3, through the port 31 The low pressure fluid is delivered to the variable mechanism 7, and the high pressure fluid is transferred through another port 32 to act on both sides of the piston 12.

Therefore, since the low pressure acts on the left side of the piston 12 and the high pressure acts on the right side, the piston 12 is moved to the left side by the hydraulic vehicle.

At this time, the hydraulic pressure acting on the right side of the outward flange F manifested on the outer circumference of the moving core 8 cancels each other, the hydraulic chamber 14 becomes a high pressure and another hydraulic chamber 13 becomes a low pressure. The core 8 is in a state of receiving a moving force to the left.

At this time, since the ball 21 is pushed to the left by the piston 12, the fluid in the left hydraulic chamber 13 is moved through the oil hole so that the moving core 8 moves to the left. Since the chamber 14 results in a larger volumetric capacity, the pressure here is lower than that of the passage 11.

Therefore, the ball 22 is pushed by the pressure applied to the right side of the piston 12, but since the high pressure fluid flows into the right hydraulic chamber 14, the moving core 8 moves to the left unless the pressure is discharged therefrom. Will be in a state.

The core moving in this way is a linear movement, wherein the phase difference between the helical gear (3) and the spline (4) that is geared to the tooth, the rotational movement and the linear movement while the phase difference is generated as the torsion of the helical gear.

In other words, the phase change due to the helical angle of the helical gear 3 and the movable side helical gear (not shown) and the phase change due to the helical angle of the helical groove 4 are combined to change the phase.

At this time, the hard hole 36 absorbs the phase difference generated in the helical gear 3 so that the connecting rod 6 connecting the mobile core 8 can move without receiving any resistance.

When the cam shaft 1 rotates, a positive force is generated. As shown in FIG. 3, when the hydraulic pressure in the right hydraulic pressure chamber 14 is greater than the hydraulic pressure in the left hydraulic pressure chamber 13, the cam shaft 1 moves to the left side. When the pressure in the right hydraulic chamber 14 is smaller than the pressure in the left hydraulic chamber 13, the pressure is moved to the right side.

That is, the difference between the hydraulic pressure acting on the left hydraulic chamber 13 and the pressure acting on the right hydraulic chamber 14 is the positive force, the frictional force, and the hydraulic force acting on the helical gear 3 both positively and positively. In this case, the helical gear 3 is intermittently advanced to the desired position.

In other words, in the section where the positive force, friction force, and hydraulic force of the helical gear 3 act on the left side, the helical gear 3 moves to the left side, and the hydraulic chamber 14 when the force acts on the right side. This high-pressure chamber prevents the helical gear 3 from moving to the right, thereby intermittently proceeding.

As described above, the variable intake / exhaust valve switching device according to the present invention outputs a signal that detects the engine speed and load from the ECU, and selectively operates two solenoid valves to drive the directional valve. By changing the phase of the camshaft by changing the phase of the camshaft by moving the helical gear splined on the camshaft with a pressure difference in the left and right hydraulic chambers, the opening and closing time of the intake and exhaust valves can be adjusted optimally according to the engine speed.

Claims (2)

The spline groove 4 formed in the helical shape and the helical gear 3 are gear-coupled to one side end of the cam shaft 1, and the flange 5 formed from the helical gear 3 and the extension of the cam shaft 1. (9) the left hydraulic chamber 13 in which the movable core 8 located on the inner hollow part is integrally connected by the connecting rod 6, and is installed around the inward flange 10 of the movable core 8, respectively. ) And the right hydraulic chamber 14 form an independent hydraulic chamber by the piston 12 located in the passage 11, and resist the fluid flowing through the oil holes 25 at both ends of the passage 11, respectively. The first elastic member is supported on the sheets 19 and 20 on which the silver balls 21 and 22 are elastically supported by the second elastic members 23 and 24 and the second elastic members 23 and 24 are supported. (17) and (18), respectively, the oil hole (25) is connected to the directional valve 27 is interlocked in accordance with the drive of the solenoid valves 34, 35 controlled by the ECU Automotive intake and exhaust valve opening and closing device for the variable, characterized in that the pressure and the low pressure fluid arranged to selectively flow into. 2. A variable opening and closing device for an automobile intake and exhaust valve according to claim 1, characterized in that the inclined hole (36) is drilled in the extension (9) of the camshaft (1) through which the connecting rod (6) passes.