KR100772012B1 - Apparatus for driving engine valve - Google Patents

Abstract

A valve drive apparatus is provided to maximize engine efficiency, and to improve fuel efficiency and output by variably controlling lift amount of a valve and opening/closing time of the valve continuously depending on an operation state of the engine. A valve drive apparatus comprises a rotation cam(110), a first locker arm(120), a second locker arm(130) and a position moving unit. The first locker arm is rotated around a first shaft line(121) by rotation of the rotation cam so as to allow the valve to be opened and closed. The second locker arm includes a second cam follower unit contacted with the rotation cam and a cam unit contacted with the first locker arm, and is rotated around a second shaft line(131) parallel to a first shaft line. The position moving unit moves the second shaft line to be rotated around a third shaft line(125) parallel to the first shaft line and the second shaft line.

Description

Valve driving device {Apparatus for driving engine valve}

1 is a view showing a conventional valve drive device.

Figure 2 is a front view of the valve drive device according to an embodiment of the present invention.

3 is a view showing a cam portion and a base portion of the valve driving apparatus shown in FIG.

4 is a view showing a state in which the first rocker arm is lowered from the state of the valve driving device shown in FIG.

5 is a view showing a state in which the first support body is rotated in the "D" direction from the state of the valve drive device shown in FIG.

6 is a front view of a valve driving apparatus according to another embodiment of the present invention.

<Description of the symbols for the main parts of the drawings>

110: rotating cam 120: the first rocker arm

121: first axis 122: first body

123: first roller 124: rotation axis of the first roller

125: third axis 130: second rocker arm

131: second axis 132: second body

133: second roller 134: cam portion

135: basic portion 142: first support

143: worm 144: worm wheel

160: spring

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a valve driving apparatus, and more particularly, to a valve driving apparatus for continuously variablely controlling lift amount and opening time of a valve for opening and closing a combustion chamber in an engine.

In general, an engine generates thermal energy by rotating a crankshaft through a connecting rod connected to the piston to explode force generated by burning fuel in a combustion chamber formed between a cylinder and a cylinder head and a piston reciprocating within the cylinder. It is a device that converts torque.

The combustion chamber is provided with an intake valve for providing a mixer containing fuel to be combusted and an exhaust valve for releasing combusted gas, which are opened and closed by a valve driving device connected to the crankshaft. It is made to The valve driving apparatus mainly uses an overhead valve method and an overhead camshaft method, both of which are connected to the crankshaft to convert the cam motion of the rotating camshaft into the linear motion of the valve.

Such a valve driving device is generally opened and closed while the valve always has a constant lift by a cam having a constant profile, a conventional valve driving device is shown in FIG. Referring to FIG. 1, the valve driving device includes a rotary cam 30 that rotates about its rotary shaft 32, and a first axis line 41 as the center of rotation in accordance with the rotation of the rotary cam 30. The rocker arm 40 which opens and closes the said valve 10 is provided with rotation.

The valve 10 is in contact with one end 40a of the rocker arm, and the valve 10 is opened and closed by the rotation of the rocker arm 40. The gap adjuster 20, which is in contact with the other end 40b of the rocker arm, always exerts an upward force on the other end 40b of the rocker arm, thereby providing one end portion 40a of the rocker arm with the valve. Adjust the gap between (10) to zero. A central portion of the rocker arm 40 is provided with a roller 42 hinged to the rocker arm 40 so as to be rotatable with respect to the rocker arm 40 to make contact with the rotary cam 30.

However, in the conventional valve driving apparatus as described above, the cam lobe 31 of the rotary cam 30 having the same shape is always in contact with the roller 42 of the rocker arm 40, and the cam lobe 31 Since the highest protrusion of the roller 42 and the roller 42 are always in contact with each other at the same position, the rocker arm 40 having the first axis 41 as the rotational center rotates only within a predetermined angle range, so that one end of the rocker arm The lift amount of the valve 10 pressed by the portion 40a is always constant. Therefore, the lift amount of the valve cannot be changed, and the opening / closing time of the intake or exhaust valves is always fixed at a constant state, so that the amount of intake or discharged air cannot be adjusted, which is optimal according to the operating state of the engine. There was a problem that can not achieve fuel economy and output.

The present invention has been made to solve the above problems, it is configured to continuously control the lift amount of the valve and the opening time of the valve in accordance with the operating state of the engine, to maximize the efficiency of the engine In addition, the object of the present invention is to provide a valve drive device with an improved structure to improve fuel efficiency and output.

In order to achieve the above object, the valve driving apparatus of the present invention is for driving a valve for opening and closing a combustion chamber in an engine, and a rotary cam, one end of which is in contact with the valve, according to the rotation of the rotary cam. A valve driving apparatus including a first rocker arm for opening and closing the valve while rotating with an axis as the center of rotation, wherein the second cam follower portion in contact with the rotary cam and the cam portion in contact with the first rocker arm are provided. And a second axis parallel to the first axis to rotate by receiving the rotational force of the rotary cam through the second cam follower to press and rotate the first rocker arm through the cam. A second rocker arm and a second rocker arm, which are possibly installed, for moving the second axis along an arc trajectory around the first axis and a third axis parallel to the second axis Moving means, and characterized by varying the amount of lift of the valve by this in accordance with the position of the second axial portion of the cam presses the amount of the first rocker arm varies.

In the valve driving apparatus according to the present invention, preferably, the second rocker arm further includes a base member formed in contact with the first rocker arm and extending from the cam portion, wherein the base member is formed by the second member. An arc shape having the second axis as a center of curvature so as not to press the first rocker arm even when the rocker arm rotates in contact with the first rocker arm, and according to the position of the second axis line, During rotation, the length of the base contact portion and the first rocker arm in rolling contact and the length of the cam portion and the first rocker arm in contact with the cloud vary.

In the valve driving apparatus according to the present invention, preferably, the first rocker arm is coupled to the first main body and the first main body which has one end contacting the valve and being rotatable about the first axis. And a first cam follower fisherman in contact with the second rocker arm.

In the valve driving apparatus according to the present invention, preferably, the third axis is such that the first rocker arm penetrates the center of curvature of the first cam follower portion in a state where the first rocker arm is not pressed by the second rocker arm. Is placed.

In the valve driving apparatus according to the present invention, preferably, the first cam follower portion is a first roller rotatably coupled to the first body.

In the valve driving apparatus according to the present invention, preferably, the second rocker arm includes a second body having the cam portion, and the second cam follower portion is rotatably coupled to the second body. It is a roller.

In the valve driving apparatus according to the present invention, Preferably, the position moving means, the motor; A first support having one end rotatably coupled to the third axis inside the engine and the other end rotatably coupled to the second rocker arm about the second axis; And a power transmission unit which transmits the driving force generated by the motor to the first support body and rotates the first support body with the third axis as the rotation center.

In the valve driving apparatus according to the present invention, preferably, the power transmission unit includes a worm that is rotated by the motor and a worm wheel that is formed on the first support and engages with the worm.

In the valve driving apparatus according to the present invention, Preferably, the position movement means, the eccentric cam to rotate eccentrically; A second support having one end rotatably fitted to the eccentric cam, and the other end rotatably coupled to the second rocker arm about the second axis; A protrusion formed to protrude from one surface of the second support; And a guide member fitted with the protrusion and having a guide hole formed to have a predetermined length along an arc trajectory around the third axis.

In the valve driving apparatus according to the present invention, preferably, further comprising a spring for elastically biasing the second cam follower portion toward the rotary cam.

Hereinafter, preferred embodiments of the valve driving apparatus according to the present invention will be described in detail with reference to the accompanying drawings.

Figure 2 is a front view of the valve driving apparatus according to an embodiment of the present invention, Figure 3 is a view showing the cam portion and the base of the valve driving apparatus shown in Figure 2, Figure 4 is a valve drive shown in Figure 2 FIG. 5 is a view showing a state in which the first rocker arm is lowered from the state of the device, and FIG. 5 is a view showing the state in which the first support body is rotated in the "D" direction from the state of the valve driving device shown in FIG.

2 to 5, the valve driving apparatus according to the present embodiment may variably control the lift amount of the valve 10 that opens and closes the combustion chamber in the engine, and includes the rotary cam 110 and the first. The rocker arm 120, the second rocker arm 130, and a position moving means are provided.

The rotary cam 110 generates a rocking motion of a constant profile so that the valve 10 can reciprocate in the vertical direction at a predetermined cycle. Each time the cam lobe 111 is rotated about its rotary shaft 112 and protruded on one side thereof, the cam cam 111 is positioned at a predetermined position on the circumference, and will be described later by the cam lobe 111. The second rocker arm 130 and the first rocker arm 120 are pressed, so that the valve 10 can also be opened and closed, that is, reciprocating in the vertical direction.

The first rocker arm 120 rotates the first axis 121 as the center of rotation according to the rotation of the rotary cam 110 to open and close the valve 10, and the first body 122. And a first cam follower fisherman. One end 122a of the first body contacts the valve 10, and the other end 122b of the first body contacts the gap adjuster 20. The gap adjuster 20 always applies an upward force to the other end 122b side of the first body to zero the gap between one end 122a of the first body and the valve 10. ). A spherical head portion 21 is provided at an upper portion of the gap adjuster 20, and the first axis 121 is disposed to penetrate the center of curvature of the head portion 21. Receiving the rotational force of the rotary cam 110, the 122 can be rotated using the first axis line 121 as the center of rotation.

The first cam follower portion in contact with the second rocker arm 130, which will be described later, is installed at the central portion of the first body 122. The first cam follower unit receives the swinging motion of the rotary cam. In this embodiment, the center of curvature of the first cam follower unit is set as the rotation axis 124 to be rotatable with respect to the first body 122. The installed first roller 123 is used.

A pivot part (not shown) in which one end portion 142a of the first support to be described later is hinged is installed in the engine, and the third axis 125 of the present embodiment is positioned on a rotation axis of the pivot part. In addition, in the third axis 125, the first rocker arm 120 is not pressed by the second rocker arm 130, that is, the first rocker arm 120 does not rotate and the valve 10 does not rotate. ) Is arranged to coincide with the position of the rotation shaft 124 of the first roller in a state where the combustion chamber is closed. When the first rocker arm 120 starts to rotate about the first axis 121, the rotation axis 124 of the first roller no longer coincides with the third axis 125 and the first axis 121. It moves along the circular arc trajectory centering on one axis 121.

The second rocker arm 130 transmits the rotational force of the rotary cam 110 to the first rocker arm 120, the position of which is changed to change the lift amount of the valve 10, A second main body 132, a second cam follower fisherman, a cam portion 134, and a base member 135 is provided.

One side of the second body 132 is provided with a second cam follower coupled to the second body 132. In this embodiment, as the second cam follower portion, a circular second roller 133 rotatably coupled to the second body 132 is used. The second roller 133 is always in contact with the rotary cam 110, and receives the rocking motion generated from the rotary cam 110.

The second rocker arm 130 is provided with a pivot part 136 to which the second main body 132 is hinged, and the second rocker arm 130 is a second axis of rotation of the pivot part 136. The axis 131 is installed in the engine so as to be rotatable with the rotation center as the center. When the rotary cam 110 is rotated and the cam lobe 111 and the second roller 133 of the rotary cam contact, the second roller 133 is pressed downward and the second rocker arm ( 130 is rotated using the second axis 131 as the center of rotation.

The cam portion 134 is formed on the lower portion of the second body 132 on the "B" section of FIG. 3 in a curved shape to receive the rocking motion of the rotary cam 110 from the second roller 133. The rocking motion is transmitted to the first rocker arm 120. When the cam lobe 111 of the rotary cam and the second roller 133 are not in contact with each other, the base circle 135 to be described later and the first roller 123 are in contact with each other. When the 111 and the second roller 133 start to contact each other, the cam part 134 starts to contact the first roller 123 while pressing the first roller 123 downward.

The base portion 135 is formed on the section “C” of FIG. 3 in a curved shape at the bottom of the second body 132 to extend from the cam portion 134, and curvature the second axis 131. It is the part of circular arc shape which centers.

Referring to FIG. 3, the base circle part 135 is a part which is always in contact with the first roller 123, and between the second axis 131 and a point at an arbitrary position on the base circle part 135. Since the distances r3 and r4 are constant, when the second rocker arm 130 rotates with the second axis line 131 as the center of rotation, the clouds of the base member 135 and the first roller 123 are rotated. While the contact occurs, the first roller 123 is not pressed downward.

On the other hand, the distance between the second axis 131 and the point at any position on the cam portion 134 is the distance between the second axis 131 and the point at any position on the base portion 135. Since it is longer, when the rolling contact between the cam part 134 and the first roller 123 starts to occur, the first roller 123 is pressed downward. In addition, the distance r1 between the second axis 131 and the point at any one position of the cam portion 134 and between the second axis 131 and the point at another position of the cam portion 134. When comparing the distance r2 of, the distance indicated by "r2" located far from the base circle 135 is longer than the distance indicated by "r1" located close to the base circle 135. The cam portion 134 is formed such that the distance between the point and the second axis line 131 becomes longer as the point on the cam portion 134 moves away from the base circle portion 135. Therefore, as the point located on the cam portion 134 in contact with the first roller 123 is farther from the base portion 135, the first roller 123 is moved downward by the cam portion 134. Will be pressed more.

The second body 132 is provided with a spring 160 for elastically biasing the second roller 133 toward the rotating cam 110. The spring 160 is wound around the pivot portion 136 of the second rocker arm and protrudes on one surface of the second body 132 and one surface of the first support 132. It is installed to be caught on the second projection 145 formed to protrude on. The restoring force by the spring 160 acts on the first protrusion 137 so that the second roller 133 is in contact with the rotary cam 110 at all times.

The position shifting means is a means for moving the second axis 131, which is the rotation center of the second rocker arm 130, along an arc trajectory around the third axis 125, and includes a motor 141. ), A first support 142, and a power transmission unit.

One end 142a of the first support 142 is rotatably coupled to the inside of the engine about the third shaft 125, and the other end 142b of the second rocker arm 130 is rotated. ) Is rotatably coupled around the second axis line 131. When the driving force of the motor 141 is transmitted to the first support 142 by a power transmission unit to be described later, the first support 142 is rotated by using the third axis 125 as the rotation center. The second rocker arm 130 coupled to the other end portion 142b of the first support body maintains contact with the first roller 123 through the base circle portion 135 while maintaining the contact with the first axis line 125. The position moves along the circular arc trajectory.

The power transmission unit transmits the driving force generated by the motor 141 to the first support 142, and meshes with the worm 143 and the worm 143 rotated by the motor 141. The worm wheel portion 144 is made up. The worm 143 is formed on a rotation shaft of the motor 141, and the worm wheel part 144 is formed on one side of the first support 142.

Hereinafter, the operation principle in which the lift amount and the opening time of the valve are variably controlled by the valve driving apparatus of the present embodiment configured as described above will be described with reference to FIGS. 2 to 5.

When the rotating cam 110 rotates and the cam lobe 111 and the second roller 133 of the rotating cam come into contact with each other, the second rocker arm 130 rotates the second axis 131 as the center of rotation. Will be rotated. Before the cam lobe 111 and the second roller 133 of the rotating cam contact each other, the base circle part 135 of the second rocker arm and the first roller 123 are in contact with each other. Rolling contact occurs between the base portion 135 and the first roller 123 with the rotation of the arm 130. Since the first roller 123 is not pressed downward while the rolling contact is generated between the base portion 135 and the first roller 123, the valve 10 keeps closing the combustion chamber of the engine. Will be in a state. When the rolling contact between the base member 135 and the first roller 123 is finished, and the contact between the cam portion 134 and the first roller 123 formed to extend from the base member 135 starts, The first roller 123 starts to be pressed downward and the first body 122 starts to rotate the first axis 121 to the rotation center. Due to the rotation of the first body 122, the valve 10 in contact with the one end portion (122a) of the first body moves in the downward direction, and eventually the combustion chamber of the engine is opened.

4 and 5, when the first support 142 rotates in the “D” direction with the third axis 125 as the rotation center, the cam portion (not shown) when the second rocker arm 130 rotates. 134 and the length of the first roller 123 is in contact with the cloud is long. That is, when the first support 142 is located at the position shown in FIG. 4, when the second rocker arm 130 is rotated, the base member 135 and the first roller 123 are relatively clouded. The length of the contact becomes long, and the length of the cam portion 134 and the first roller 123 in contact with the cloud becomes short. On the other hand, when the first support 142 is located at the position shown in FIG. 5, when the second rocker arm 130 is rotated, the base member 135 and the first roller 123 are relatively The length of the rolling contact becomes shorter, and the length of the cam portion 134 and the first roller 123 in rolling contact becomes longer.

When the length of the cam portion 134 and the first roller 123 is in contact with the cloud becomes short, the first roller 123 is brought into contact with a point on the cam portion 134 located close to the base circle 135. The valve 10 descends only from the "A0" position to the "A1" position and reciprocates between the "A0" position and the "A1" position according to the rotation of the rotary cam 110. However, when the length of the cam portion 134 and the first roller 123 is in contact with the cloud is long, the first roller 123 is in contact with the point on the cam portion 134 located far from the base portion 135. Thus, the valve 10 is lowered from the "A0" position to the "A2" position and reciprocating between the "A0" position and "A2" position in accordance with the rotation of the rotary cam 110.

In addition, the opening time of the valve is also changed as the position of the second rocker arm 130 moves in the left and right directions. For example, in the position shown in FIG. 4, the contact between the highest protrusion on the cam lobe 111 and the second roller 133 is approximately 6 o'clock, and in the position shown in FIG. The contact of the highest protrusion and the second roller 133 is made at approximately 5 o'clock. As such, the time at which the contact between the highest protrusion on the cam lobe 111 and the second roller 133 occurs is changed so that the opening time of the valve 10 is also changed.

When the valve driving apparatus according to the present embodiment configured as described above is used, the cam portion and the first portion are changed by changing the relative positions of the first rocker arm whose one end is in contact with the valve and the cam portion which is in contact with the first rocker arm. By varying the length of the rocker arm in rolling contact, the lift amount and opening time of the valve can be continuously controlled, thereby changing the lift amount of the valve and the opening and closing time of the valve according to the operating state of the engine. By adjusting the amount of intake or exhaust air, it is possible to achieve the optimum fuel economy and output according to the operating state of the engine.

On the other hand, Figure 6 is a front view of the valve driving apparatus according to another embodiment of the present invention.

Referring to Fig. 6, the valve drive device of the present embodiment is provided with position moving means different from the valve drive device shown in Fig. 2. The position shifting means of this embodiment includes an eccentric cam 151, a second support 152, a protrusion 153, and a guide member 154. In FIG. 5, members referred to by the same reference numerals as the members shown in FIGS. 2 to 5 have the same configuration and function, and detailed descriptions thereof will be omitted.

The eccentric cam 151 rotates eccentrically about its rotation axis, and provides a rocking motion to a member fitted to the eccentric cam 151.

The second support 152 is rotatably fitted with an eccentric cam 151 at one end thereof, and the other end thereof is centered on the second axis 131 at the pivot portion 136 of the second rocker arm. Rotatably coupled. One surface of the second support 152 is provided with a protrusion 153 formed to protrude from one surface thereof.

The protrusion 153 is fitted to the guide member 154 so that the protrusion 153 can move along an arc trajectory around the third axis 125 and is centered on the third axis 125. A guide hole 155 having a predetermined length is formed along the arc of the arc. As the eccentric cam 151 rotates, the second support 152 is free to move, and the protrusion 153 provided in the second support 152 is configured to fit in the guide hole 155. The movement of the second support 152 is constrained according to the direction in which the guide hole 155 is formed, and the pivot portion 136 of the second rocker arm has a circular arc trajectory centered on the third axis 125. Move along.

The valve driving device according to the present embodiment can also obtain the same effect as the valve driving device shown in FIG. 2.

Although preferred embodiments and modifications have been described above, the valve driving apparatus according to the present invention is not limited to the above-described examples, and various modifications and combinations thereof may be made within the scope not departing from the technical spirit of the present invention. A valve drive device of the type can be embodied.

According to the valve driving device of the present invention, the variable control amount of the valve lift amount and the opening and closing time of the valve can be continuously controlled according to the operating state of the engine, thereby maximizing the efficiency of the engine and improving fuel efficiency and output. There is.

Claims (10)

A first drive for driving a valve for opening and closing the combustion chamber in the engine, the rotary cam, and one end thereof in contact with the valve and rotates the first axis in the center of rotation in accordance with the rotation of the rotary cam to open and close the valve. In the valve drive device comprising a rocker arm, A second cam follower contacting with the rotating cam and a cam part contacting with the first rocker arm, and receiving the rotational force of the rotary cam through the second cam follower and receiving the first rocker through the cam part; A second rocker arm rotatably provided with a second axis parallel to the first axis to rotate the arm so as to rotate the arm; And position moving means for moving the second axis along an arc trajectory around the first axis and a third axis parallel to the second axis. And a lift amount of the valve is changed by changing the amount of pressing the first rocker arm by the cam part according to the position of the second axis. The method of claim 1, The second rocker arm further includes a base portion formed in contact with the first rocker arm and extending from the cam portion. The base portion has an arc shape having the second axis as a center of curvature so that the first rocker arm is not pressed even when the second rocker arm rotates in contact with the first rocker arm. According to the position of the second axis, the length of the base contact portion and the first rocker arm in rolling contact and the length of the cam portion and the first rocker arm in contact with the cloud when the rotation of the second rocker arm is different. Valve drive system. The method of claim 1, The first rocker arm, One end portion includes a first body in contact with the valve and rotatable around the first axis, and a first cam follower portion coupled to the first body and in contact with the second rocker arm. Drive system. The method of claim 3, And the third axis is arranged to pass through the center of curvature of the first cam follower portion in a state where the first rocker arm is not pressed by the second rocker arm. The method of claim 3, The first cam follower portion, the valve driving device, characterized in that the first roller rotatably coupled to the first body. The method of claim 1, The second rocker arm includes a second body having the cam portion, And the second cam follower portion is a second roller rotatably coupled to the second body. The method of claim 3, The position moving means, motor; A first support having one end rotatably coupled to the inside of the engine about the third axis, and the other end rotatably coupled to the second rocker arm about the second axis; And And a power transmission unit which transmits the driving force generated by the motor to the first support and rotates the first support with the third axis as the rotation center. The method of claim 7, wherein The power transmission unit, And a worm wheel portion formed on the first support and engaged with the worm, the worm being rotated by the motor. The method of claim 1, The position moving means, Eccentrically rotating eccentric cam; A second support having one end rotatably fitted to the eccentric cam, and the other end rotatably coupled to the second rocker arm about the second axis; A protrusion formed to protrude from one surface of the second support; And And a guide member having the guide portion inserted therein and having a guide hole formed in a predetermined length along an arc trajectory around the third axis. The method of claim 1, And a spring for elastically biasing the second cam follower portion toward the rotary cam.

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