JPH11210416A - Valve driving device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a valve driving device certainly controlling the separating distance of a valve element from a valve sheet by ensuring the stable oscillation of an arm. SOLUTION: This valve driving device 1 is equipped with the cylinder head 2 (fixing member) of an internal combustion engine, a valve sheet 3 arranged on the cylinder head 2, a valve element 4, a rocker arm 5 freely swingably supported on the cylinder head 2, a first eccentric rotary cam 6, a bearing part 7 arranged on the cylinder head 2 and also freely swingably supporting the rocker arm 5, and a second eccentric rotary cam 8. The valve element 4 is equipped with an approximately rodlike shaft part 4a, a valve element part 4b arranged in one side part of the shaft part 4a and brought into contact/ separated with/from the valve sheet 3, and a roller 4c rotatively arranged in the other side part of the shaft part 4a. The second eccentric rotary cam 8 pivots movably a shaft 10 and moves the rocker arm 5 to the cylinder head 2, so that distance between an abutting part S and the shaft 10 is increased and reduced in the cylinder head 2 that does not move to the rotary shaft 6a.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a valve driving device in which a valve body is lifted from a valve seat by swinging an arm, and more particularly to a rocker arm type valve driving device for a vehicle.

[0002]

2. Description of the Related Art A conventional valve driving device is disclosed in
As disclosed in Japanese Patent Publication No. 187212, a valve seat, a valve body which can be brought into contact with and detached from the valve seat, and one side of which is in contact with the valve body and which is swingable on the other side. And an arm that adjusts the amount of separation of the valve body from the valve seat according to the amplitude associated with the swing while the valve body contacts and separates from the valve seat by being swung, and A rotating cam that abuts the arm between one side portion of the arm and the other side portion of the arm, and swings the arm by rotating, and makes a point contact with the outer peripheral portion of the other side portion of the arm. A support member that swingably supports the arm and has a contact portion with the arm as a swing fulcrum of the arm; and a moving unit that moves the support member with respect to the arm. Are known.

In this conventional valve driving device, when the supporting member is moved with respect to the arm by the moving means, the contact portion between the arm and the supporting member moves, and the pivot point of the arm moves to the axis of the rotary cam. Moved against. As the swing fulcrum of the arm is moved, the amplitude associated with the swing of the arm is increased or decreased, and the amount of separation of the valve body from the valve seat is increased or decreased.

[0004]

However, in this conventional valve driving device, the assembling relationship between the arm and the support member is made only by the contact between the arm and the support member.
If a state occurs in which the contact between the arm and the support member is not reliably performed, the swinging fulcrum of the arm is not determined, and stable swinging of the arm is not ensured, and the amount of separation of the valve body from the valve seat is reduced. There is a risk that it cannot be secured accurately.

An object of the present invention is to provide a valve driving device capable of ensuring stable swinging of an arm and accurately controlling the amount of separation of a valve body from a valve seat.

[0006]

In order to solve the above problems, a valve seat, a valve body which can be brought into contact with and detached from the valve seat, a rotary cam having a rotary shaft, and one side portion thereof are provided. The rotating cam is in contact with the valve body and is swingably supported at a shaft portion disposed on the other side portion, and abuts on the rotating cam between the one side portion and the other side portion, and rotates the rotating cam. An arm for swinging the valve body to abut and separate from the valve seat and adjusting an amount of separation of the valve body from the valve seat according to an amplitude associated with the swing operation; A fixing member that movably supports the shaft so that the distance between the contact portion with the arm and the shaft of the arm is increased or decreased, and that is not moved with respect to the rotation axis of the rotating cam; Moving means for moving the member with respect to the fixed member. It was to constitute a valve driving device.

According to the first aspect of the present invention, the shaft of the arm is supported by the fixed member, and the moving means moves the shaft of the arm, so that the amplitude accompanying the swing of the arm and, consequently, the valve body. Is increased or decreased with respect to the valve seat.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to embodiments.

FIG. 1 is a sectional view of a rocker arm type valve drive device 1 for a vehicle as a valve drive device according to an embodiment of the present invention, and FIG. 2 is a partial sectional view of an upper portion of the valve drive device 1 of FIG. is there. As shown in FIGS. 1 and 2, a valve driving device 1 is provided on a cylinder head 2 (fixed member) of an internal combustion engine (not shown), a valve seat 3 provided on the cylinder head 2, and a cylinder head 2. Valve body 4, rocker arm 5 swingably supported by cylinder head 2, first eccentric rotary cam 6, and a bearing disposed on cylinder head 2 and supporting rocker arm 5 to be swingable. Part 7,
And a second eccentric rotary cam 8 (moving means).

A gas passage 9 communicating with the annular valve seat 3 is formed in the cylinder head 2. The valve body 4 is rotatable about a substantially rod-shaped shaft portion 4a, a valve body portion 4b disposed on one side portion of the shaft portion 4a and coming into contact with and detaching from the valve seat 3, and another side portion of the shaft portion 4a. Has a roller 4c disposed at the center.

The valve element 4 has an axial direction (vertical direction in FIG. 1).
The cylinder head 2 is disposed so as to be able to reciprocate. Between the cylinder head 2 and the spring retainer 13c disposed on the other side of the shaft portion 4a of the valve body 4,
The valve body 4 is so positioned that the valve body portion 4b of the valve body 4 is brought into contact with the valve seat 3.
A first spring 12 for urging the upper part in FIG. 1 is provided.

The cylinder head 2 has a first mounting hole 2a extending in a direction perpendicular to the axis of the valve body 4 (left-right direction in FIG. 1).
Are formed. A bearing 7 is slidably disposed in the first mounting hole 2a.

The rocker arm 5 abuts the roller 4c of the valve body 4 at one side 5a, and a shaft 10 is provided at the other side 5b.
Is pivotally supported. The shaft 10 as the rocking axis of the rocker arm 5 and the axis of the valve body 4 are disposed so as to be perpendicular to each other, and the first mounting hole 2 a is perpendicular to the axis of the valve body 4 and the shaft 10. Extending in different directions.

The rotary shaft 6a of the first eccentric rotary cam 6 is provided so as not to move with respect to the cylinder head 2. The first eccentric rotary cam 6 is in contact with a portion S between one side portion 5a and the other side portion 5b of the rocker arm 5.
The rotation shaft 6a of the first eccentric rotary cam 6 is parallel to the shaft 10 of the rocker arm 5, and the first eccentric rotary cam 6
Is rotated, the rocker arm 5 swings about the shaft 10.

A first mounting hole 2a is formed in the cylinder head 2.
A second assembly hole 2b is formed on the opposite side (right side in FIG. 1) from the side where the rocker arm 5 is located in the extending direction of the first assembly hole 2a (left-right direction in FIG. 1). I have. The second mounting hole 2b is provided with a second eccentric rotary cam 8 which is in contact with an end face of the bearing portion 7 opposite to the side where the rocker arm 5 is located.

The rotary shaft 8a of the second eccentric rotary cam 8 is
The eccentric rotary cam 6 is provided so as to be parallel to the rotation shaft 6a. The rotation of the second eccentric rotary cam 8 moves the bearing 7 in the first mounting hole 2a.

In the first mounting hole 2a, a bearing is provided between an end surface of the bearing portion 7 on the side where the rocker arm 5 is located (left side in FIG. 1) and an opposing portion of the cylinder head 2 opposing the end surface. A second spring 11 for urging the portion 7 toward the second eccentric rotary cam 8 is provided. Due to the urging force of the second spring 11 and the rotation of the second eccentric rotary cam 8, the bearing 7 is reciprocated in the first mounting hole 2a.

Next, the operation of the valve driving device 1 will be described. In the initial state shown in FIGS. 1 and 2, the valve body 4 b of the valve body 4 abuts on the valve seat 3, and the bearing 7 is in the first mounting hole 2.
a, the outermost position with respect to the first eccentric rotary cam 6.

When the first eccentric rotary cam 6 is rotated, for example, clockwise in FIG. 1 about the rotary shaft 6a, the rocker arm 5 moves the shaft 10 in the vertical direction in FIG. Rocked. When the rocker arm 5 swings downward from the initial state shown in FIG. 1, one end 5 a of the rocker arm 5 pushes the valve body 4 downward in FIG. 1 against the urging force of the first spring 12. Then, the valve body 4 is moved downward with respect to the cylinder head 2.

When the valve body 4 moves downward with respect to the cylinder head 2, the valve body portion 4b of the valve body 4 is separated from the valve seat 3, and the gas passage 9 is communicated with the outside of the cylinder head 2. After the rocker arm 5 swings downward after the rocker arm 5 swings downward, the valve body 4 follows the one side portion 5a of the rocker arm 5 by the urging force of the first spring 12 so that the cylinder head 2 Is moved upward.

The upward movement of the valve body 4 causes the valve body portion 4b
Abuts on the valve seat 3 to cut off communication between the gas passage 9 and the outside of the cylinder head 2. Therefore, the first eccentric rotary cam 6
Is rotated to rock the rocker arm 5, and the rocking of the rocker arm 5 opens and closes the valve constituted by the valve element 4 and the valve seat 3.

From the state shown in FIG. 1, the second eccentric rotary cam 8
Is rotated forward (counterclockwise in FIG. 1) by a predetermined amount, the bearing portion 7 faces the first eccentric rotary cam 6 in the first mounting hole 2 a against the second spring 11, that is, It is moved a predetermined amount to the left in FIG. With the movement of the bearing 7, the rocker arm 5 is also moved to the left in FIG. 1 by a predetermined amount with respect to the first eccentric rotary cam 6, the valve body 4, and the cylinder head 2 via the shaft 10.

When the rocker arm 5 is moved, the contact portion S of the rocker arm 5 with the first rotary cam 6 in the initial state of FIG. The rocking fulcrum of the rocker arm 5 approaches the rotating shaft 6 a of the first eccentric rotating cam 6.
That is, with respect to the distance between the contact portion S between the rocker arm 5 and the first eccentric rotary cam 6 in the initial state shown in FIG. 1 and the rocking fulcrum of the rocker arm 5, the rocker arm 5 is moved from the initial state in FIG. When the rocker arm 5 is moved by a predetermined amount, the distance between the contact portion between the rocker arm 5 and the first eccentric rotary cam 6 and the pivot of the rocker arm 5 becomes shorter.

Therefore, the amplitude accompanying the rocking of the rocker arm 5 becomes larger than the amplitude accompanying the rocking of the rocker arm 5 in the initial state shown in FIG. Consequently, the amplitude accompanying the reciprocating movement of the valve element 4 also increases, and the amount of separation of the valve element section 4b from the valve seat 3 also increases.

From the initial state shown in FIG.
Is rotated forward (counterclockwise in FIG. 1) by a predetermined amount, and when the second eccentric cam 8 is rotated reversely (clockwise in FIG. 1) by a predetermined amount, the bearing 7 is biased by the second spring 11. As a result, it is moved in the first mounting hole 2a by a predetermined amount in a direction away from the first eccentric rotary cam 6, that is, rightward in FIG. With the movement of the bearing 7, the rocker arm 5 is also moved to the right in FIG. 1 by a predetermined amount with respect to the first eccentric rotary cam 6, the valve body 4, and the cylinder head 2.

When the rocker arm 5 is moved, the contact portion of the rocker arm 5 with the first eccentric rotary cam 6 is rotated when the second rotary cam 8 is rotated forward by a predetermined amount from the initial state of FIG. The rocker arm 5 is shifted leftward in FIG. 1 as compared with the contact portion of the rocker arm 5 with the first eccentric rotary cam 6.
Separate from a. That is, the distance between the contact portion between the rocker arm 5 and the first eccentric rotary cam 6 when the second eccentric rotary cam 8 is rotated forward by a predetermined amount from the state shown in FIG. On the other hand, after the second eccentric rotary cam 8 is rotated forward by a predetermined amount from the state of FIG. 1, the second eccentric rotary cam 8 is rotated reversely by a predetermined amount, and the rocker arm 5 is moved rightward in FIG. In this case, the distance between the contact portion between the rocker arm 5 and the first eccentric rotary cam 6 and the pivot of the rocker arm 5 becomes longer.

Accordingly, the amplitude accompanying the rocking of the rocker arm 5 is smaller than the amplitude accompanying the rocking of the rocker arm 5 when the second rotary cam 8 is rotated counterclockwise by a predetermined amount from the initial state shown in FIG. Is also smaller. As a result, the amplitude accompanying the reciprocating movement of the valve element 4 also decreases, and the amount of separation of the valve element portion 4b from the valve seat 3 also decreases.

That is, the distance between the valve body 4b and the valve seat 3 is adjusted in accordance with the movement of the rocking fulcrum of the rocker arm 5 accompanying the movement of the rocker arm 5. By appropriately adjusting the rotation of the second eccentric rotary cam 8 and, consequently, the amount of movement of the rocker arm 5, it is possible to continuously adjust the amount of separation between the valve body 4b and the valve seat 3.

As described above, in the valve driving device 1 of the present embodiment, the shaft 10 which is the rocking shaft of the rocker arm 5 is stably supported on the cylinder head 2 via the bearing 7. Therefore, since the rocking center or the rocking fulcrum of the rocker arm 5 does not shift, the rocking of the arm 5 can be ensured. The valve body 4
The distance between b and the valve seat 3 can be stably secured.

Accordingly, it is possible to provide the valve driving device 1 which ensures stable rocking of the rocker arm 5 and can accurately control the amount of separation of the valve body 4 from the valve seat 3.

In the present embodiment, the valve drive device of the present invention is configured as a rocker arm type valve drive device for a vehicle. However, the present invention is not particularly limited to this configuration. If the present invention is adopted in a valve drive device for continuously controlling the pressure according to the swing of the arm, the same operation and effect can be obtained.

In the present embodiment, the second eccentric rotary cam 8 is used as a moving means for moving the rocker arm 5 with respect to the cylinder head 2, but the present invention is not particularly limited to this configuration. Any means capable of moving the rocker arm 5 with respect to the cylinder head 2 may be used.

Although the present invention has been described based on the above embodiments, the present invention is not limited to the above embodiments but includes various embodiments according to the principle of the present invention.

[0034]

According to the first aspect of the present invention, since the arm is configured to swing stably, the swing of the arm can be ensured, and further, the separation between the valve body and the valve seat can be achieved. The quantity can be secured stably.

Therefore, a stable swing of the arm is ensured,
It is possible to provide a valve drive device capable of accurately controlling the amount of separation of a valve body from a valve seat.

[Brief description of the drawings]

FIG. 1 is a sectional view of a valve driving device 1 according to a first embodiment.

FIG. 2 is a partial top view of the valve driving device 1 of FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Valve drive device 2 Cylinder head 3 Valve seat 4 Valve element 5 Rocker arm 5a One side part 5b Other side part 6 First eccentric rotary cam 6a Rotary shaft 8 Second eccentric rotary cam 10 Shaft S Contact part

Claims (1)

[Claims] 1. A valve seat, a valve body that can be brought into and out of contact with the valve seat, a rotary cam having a rotating shaft, and one side of which is in contact with the valve body and arranged on the other side. The pivot shaft is swingably supported at the provided shaft portion, and abuts on the rotating cam between the one side portion and the other side portion,
An arm that is oscillated by the rotation of the rotary cam to abut and separate the valve body from and to the valve seat and adjusts the amount of separation of the valve body from the valve seat according to the amplitude associated with the swing operation; The shaft portion is movably supported so that the distance between the contact portion between the rotating cam and the arm and the shaft portion of the arm is increased or decreased, and is fixed not to be moved with respect to the rotating shaft of the rotating cam. A valve driving device comprising: a member; and a moving unit configured to move the arm with respect to the fixed member.