JPH0232448B2 - - Google Patents

Description

Detailed Description of the Invention (Industrial Field of Application) The present invention relates to a valve operating system that controls the opening and closing of intake and exhaust valves. Relating to an actuation device.

(Prior art) In general, in the case of a multi-cylinder engine, when the engine has surplus power such as when idling, decelerating, or descending a slope, the intake and exhaust of specific cylinders are stopped so that the operation of some of the cylinders is stopped. It is preferable to stop the operation of the valve in order to improve fuel efficiency.

In addition, in the case of a so-called dual induction intake type engine that has two intake ports, one for low load and one for high load, when the engine is running at low load, intake air is supplied only from the low load intake port. It is possible to open and close only the low-load intake valve that opens and closes the load intake port, and to stop the operation of the high-load intake valve that opens and closes the high-load intake port, due to the intake air from the low-load intake port. Effectively creates a strong intake swirl within the combustion chamber,
It is known that this is preferable for improving combustion stability and fuel efficiency.

Conventionally, there is a mechanical type device as disclosed in Japanese Patent Publication No. 55-26285 as a device for rendering the intake and exhaust valves inactive.

The mechanical type described above includes a rocker arm operating body, a rocker arm extending between the rocker arm operating body and the valve of the internal combustion engine, and a rocker arm that swings from the rocker arm to transmit the motion of the rocker arm to the valve. and a fulcrum support device disposed intermediate both ends of the rocker arm;
a load transmission device stacked on the fulcrum and configured to be able to float together with the fulcrum in the fulcrum support device;
an intervening device that can move laterally with respect to the fulcrum support device to a position where it blocks movement of the load transfer device; and an intervening device that is movable to a position where it blocks movement of the load transfer device. The load transmitting device includes a biasing device for pushing the load transmitting device in a certain direction, and an actuating device for selectively moving the intervening device toward or away from the load transmitting device movement blocking position. When the intervening device is in a position where it prevents movement of the load transfer device, it prevents the load transfer device from floating between the fulcrum, thereby fixing the swing axis of the rocker arm at a fixed position and operating the valve. When the intervening device is in a position where it does not block the movement of the load transfer device, the load transfer device and the fulcrum are prevented from floating on the fulcrum support device in response to rocking of the rocker arm by the rocker arm operating body. The permitting prevents the rocker arm from transmitting movement of the rocker arm actuator to the valve, rendering the valve inoperative.

(Problem to be Solved by the Invention) However, in this type of device, the intervening device is placed at a position that prevents the movement of the load transmission device only when the cam surface of the camshaft that operates the rocker arm actuating body is on the reference circle. It is a mechanism that allows for room to advance. Therefore, the valve can only be switched from the non-operating state to the operating state when the Rocker arm operating body contacts the reference circle of the cam surface of the camshaft during one revolution of the camshaft, and when the engine is running at high speeds, the camshaft Since the engine is rotating at a high speed, it is difficult to perform the above switching, and there is a drawback that switching can only be performed when the engine is operating at low speed. For this reason, it has been particularly difficult to apply this method to a dual induction type high-load intake valve, which remains inactive even during low-load, high-speed operation.

The present invention has been made in view of the above problems, and it is possible to switch a valve from an inactive state to an active state without causing an increase in engine drive loss, not only when the engine is running at low speeds but also when the engine is running at high speeds. It is an object of the present invention to provide an engine valve deactivation device that can be operated smoothly even at times.

Furthermore, when applied to a multi-cylinder engine, the present invention does not have a complicated structure, and each valve can be switched from an inoperative state to an operating state with a single control force. The purpose is to provide a device.

(Means for Solving the Problems) The present invention is based on a valve deactivation device for a multi-cylinder engine having a plurality of cylinders, and in order to achieve the above object, each of the cylinders has a valve deactivation mechanism. , each valve deactivation mechanism is slidable on an intake or exhaust valve that is always biased in the closing direction by a spring, a Rocker arm that transmits the movement of the cam surface of the camshaft to the valve, and an engine fixing part. a fulcrum member that is supported by the rocker arm and constitutes a fulcrum of the rocker arm; an intermediate member that is disposed to be slidable in the same direction as the sliding direction of the fulcrum member; and a fulcrum member that is compressed between the fulcrum member and the intermediate member. a first cam surface that presses the intermediate member toward the rocker arm in the first position against the biasing force of the spring member to bring the intermediate member into contact with the fulcrum member, thereby activating the valve; a cam having a second cam surface that causes the intermediate member to be relatively separated from the fulcrum member by the biasing force of the spring member in the second position, thereby rendering the valves inoperative; each of the valves is inoperable; A feature of the mechanism is that a cam of the mechanism is attached to a shaft extending in the longitudinal direction of the engine, corresponding to each cylinder.

(Operation) When the cam of the valve deactivation mechanism is positioned at the first position, the intermediate member pressed by the first cam surface contacts the fulcrum member and presses the fulcrum member against the rocker arm, thereby causing the fulcrum member to The rocker arm swings in response to the movement of the cam surface of the camshaft using the rocker arm as a fulcrum, and the movement of the cam surface is transmitted to the valve, thereby activating the valve.

On the other hand, when the cam of the valve deactivation mechanism is positioned at the second position, the intermediate member regulated by the second cam surface separates from the fulcrum member and puts the fulcrum member in a floating state, thereby causing the cam of the camshaft to float. The rocker arm is allowed to float together with the fulcrum member in response to the movement of the cam surface, and the movement of the cam surface is not transmitted to the valve, resulting in an inoperative state.

(Example) Hereinafter, an example of the present invention will be described in detail with reference to the drawings.

Figures 1 and 2 show the present invention applied to a dual-induction intake type three-port engine in which one cylinder is provided with two intake ports for low load and one for high load, and one exhaust port. An example of application is shown.

Reference numeral 1 denotes a cylinder head (engine fixed part), which forms a cylinder 2 constituting a combustion chamber, and this cylinder 2 has a pair of intake ports 3a and 3b for low load and high load, respectively, in parallel. Further, an exhaust port 4 is provided to open opposite the intake ports 3a and 3b. The low-load intake port 3a is formed with a relatively narrow passage area to increase the intake flow rate, and is curved so as to form a swirl of intake air within the cylinder 2. On the other hand, the high-load intake port 3b is formed to have a relatively large passage area in order to increase intake air filling efficiency. In addition, at the openings of the low-load and high-load intake ports 3a and 3b to the cylinder 2, each intake port 3a and 3b has an intake valve 5 for low-load and high-load use that opens and closes at predetermined timing, respectively.
a and 5b are arranged. On the other hand, exhaust port 4
An exhaust valve 6 that opens and closes the exhaust port 4 at a predetermined timing is disposed at the opening to the cylinder 2.
Each intake valve 5a, 5b and exhaust valve 6 are arranged in a V shape. A spark plug 7 is provided facing approximately the upper center of the cylinder 2 .

A valve operating mechanism 8 comprising a rocker arm type overhead cam mechanism for controlling the opening and closing of low-load and high-load intake valves 5a, 5b and an exhaust valve 6 is disposed above the cylinder head 1. This valve train 8 has a single camshaft 9 that extends in the direction of the center line of the cylinder head 1 and is rotationally driven by a crankshaft (not shown) of the engine.
However, the camshaft 9 has each intake valve 5a,
5b and a cam surface 9a corresponding to the exhaust valve 6 is formed. Further, one end of each valve 5a, 5b, 6 corresponds to a valve spring 11 that biases each valve 5a, 5b, 6 slidably supported by a valve guide 10 in the valve closing direction, that is, upwardly. On the cam surface 9a of the camshaft 9, the other end is connected to each valve 5a,
A swingable rocker arm 12 that contacts the valve stems 5s and 6s of the cylinder heads 5b and 6, respectively, and transmits the movement of the cam surface 9a to the respective valves 5a, 5b and 6, and a support member 14 fixed to the cylinder head 1 are fitted. The rocker arm 12 is fitted into and held in the insertion holes 14a and 14b so as to be slidable in the vertical direction, and the hemispherical tip portion 13a is fitted into and abutted on the spherical recess 12a formed in the intermediate portion of the rocker arm 12. A fulcrum member 13 is provided, which constitutes a fulcrum of the
The rotation of the camshaft 9 causes the rocker arm 12 to rotate.
The valves 5a, 5b, and 6 are opened and closed by swinging about the tip 13a of the fulcrum member 13 as a fulcrum. Fitting hole 14a of support member 14
are on the exhaust valve 6 side and the low-load intake valve 5a side, and are bottomed at the top, while the insertion hole 14b is on the high-load intake valve 5b side and penetrates vertically (see Fig. 4). ). Further, the support member 14 is formed integrally with each cam cap 14c constituting the bearing of the camshaft 9, and is fixed to the cylinder head 1 by a bolt 114 (see FIG. 3). The support member 14 has reinforcing ribs 14e on both sides that connect a cam cap portion 14c and a cylindrical portion provided with insertion holes 14a and 14b. Each Rotsuker arm 12 is
The valve stems 5s, 6s have protrusions 12c on both sides of the camshaft 9 in the axial direction to ensure engagement at the contact portions with the valve stems 5s, 6s.

Furthermore, on the exhaust valve 6 side of the valve mechanism 8,
A hydraulic tappet 15 is slidably disposed within the fulcrum member 13. The upper end of the hydraulic tappet 15 contacts the bottom of the insertion hole 14a, and the lower end contacts the rod portion 13b formed in the center of the fulcrum member 13 so as to protrude upward, and the spring 16
is urged upward (to the bottom side of the insertion hole 14a),
Therefore, the fulcrum member 13 is pressed toward the rocker arm 12 side with good followability by the hydraulic tappet 15, thereby preventing the occurrence of valve clearance. Furthermore, the low-load intake valve 5a side of the valve mechanism 8 is configured in the same manner as the exhaust valve 6 side with respect to the support member 14.

On the other hand, on the high-load intake valve 5b side of the valve operating mechanism 8, the sliding direction of the fulcrum member 13 is An intermediate member 17 is slidably inserted in the same direction as the spring member 1, and a spring member 1 is compressed between the intermediate member 17 and the fulcrum member 13.
8 and a cam member 19 rotatably supported on the support member 14 and abutting the intermediate member 17.

The cam member 19 presses the intermediate member 17 toward the rocker arm 12 side, that is, downwardly, against the biasing force of the spring member 18 in the first position, thereby bringing the intermediate member 17 into contact with the upper end of the rod portion 13b of the fulcrum member 13. A cam 20 having a first cam surface 20a and a second cam surface 20b that separates the intermediate member 17 at the second position from the fulcrum member 13 by the biasing force of the spring member 18, and the cam 20 is fitted and supported and extends in the longitudinal direction of the engine. Shaft 2 extending to
1 is wound around the shaft 21, one end is fitted onto the shaft 21, the other end is locked in the notch 20c of the cam 20, and the cam 20 is moved in the pressing direction of the intermediate member 17 (in the opposite direction in FIG. 1). a spring 22 that is elastically engaged in a clockwise direction), and a pair of pins 2 that are fixed to the cam 20 and the shaft 21, respectively.
3 and 24. Further, the shaft 21, into which the cam 20 is fitted corresponding to each cylinder 2, is rotatably supported by a bearing 121 on the upper part of the rocker arm cover 1a fixed to the cylinder head 1. (See Figure 5 a, b).

When the shaft 21 is rotated by a drive mechanism (not shown) and positioned at the first position during high-load operation of the engine, the cam 20 of the cam member 19 contacts the first cam surface 20a of the cam 20 with the intermediate member. The fulcrum member 13 pressed through the rocker arm 17 is pressed against the rocker arm 12, whereby the fulcrum member 1
3 as a fulcrum, the rocker arm 12 swings, transmitting the movement of the cam surface 9a of the camshaft 9 to the high-load intake valve 5b, and puts the high-load intake valve 5b into an operating state (see FIG. 6). When transitioning from the second position described later to the first position, the rocker arm 12 is in the raised position (see the chain line in FIG. 6) by the cam of the camshaft 9 at the beginning of the transition or during the transition, and the cam 20 of the cam member 19 When a considerable force is required to press the intermediate member 17, the rotational force transmitted from the shaft 21 to the cam 20 is absorbed by the spring 22, and the rocker arm 12 is moved to the lowered position, that is, on the reference circle of the cam surface 9a. When the cam 20 comes into contact (see the solid line in FIG. 6), the cam 20 is completely rotated to the first position. Therefore, when the rocker arm 12 comes into contact with the cam portion of the cam surface 9a during this switching, the high-load intake valve 5b opens with a lift amount smaller than the lift amount during normal operation.

On the other hand, during low load operation of the engine, the pin 23 of the cam 20 is pressed by the pin 24 of the shaft 21, and the cam 20 rotates to the second position. The intermediate member 17 and the fulcrum member 13 are separated from each other, and the fulcrum member 13 is placed in a floating state via the intermediate member 17, so that the rocker arm 12 and the fulcrum member 13 are moved in accordance with the movement of the cam surface 9a of the camshaft 9. floats, the movement of the cam surface 9b is not transmitted to the high-load intake valve 5b, and the high-load intake valve 5b is rendered inoperative, thereby forming a valve inoperation mechanism A according to the present invention.

Next, the structure of the intermediate member 17 will be explained in detail with reference to FIGS. 6 to 8.

The intermediate member 17 has a hydraulic tappet structure, and has a pressure receiving part 2 at the upper part that receives the pressing force from the cam member 19.
5a and a cylindrical first member 25 with a bottom, which has a cylindrical sliding part 25b that slides inside the fulcrum member 13 on the side thereof.
The first member 25 is slidably fitted in a liquid-tight manner, and has a pressing portion 26a that contacts the rod portion 13b of the fulcrum member 13 at the bottom and a communication hole 26 at the center.
The second member 26 has a bottomed cylindrical shape and has a partition wall portion 26c provided with a pressure point b, and an oil reservoir chamber 26d is defined between the partition wall portion 26c and the bottom portion (pressing portion 26a). It consists of. An oil chamber 27 is defined by the inner surface of the first member 25 and the partition wall portion 26c of the second member 26.
A check ball 28 is provided above the partition wall 26c (on the oil chamber 27 side) at a position facing the communication hole 26b.
a and a spring 28b, the oil sump chamber 26
A check valve 28 is provided to allow oil to flow into the oil chamber 27 through the communication hole 26b. A first communication hole 13c is provided in the peripheral wall of the fulcrum member 13 at a position facing an oil passage 14d formed in the support member 14 and communicating with an oil pump (not shown), and the first communication hole 13c 2
5b is provided with a second communication hole 25c at a position facing the first communication hole 13c, and a second communication hole 25c is provided in the peripheral wall of the second member 26 at a position opposite to the second communication hole 25c.
A third communication hole 26e that opens at 6d is provided. Therefore, the oil reservoir chamber 26d of the second member 26 is
The third communication hole 26e, the second communication hole 25c and the first
It communicates with the oil passage 14d through the communication hole 13c. Further, on the lower inner circumferential wall of the first member 25, a second
A retaining member 29 for retaining the member 26 is provided.

Therefore, the oil pumped by the oil pump into the oil passage 14d formed in the support member 14 flows through the first to third communication holes 13c, 25c, 26.
The oil is supplied to the oil reservoir chamber 26d through e.

When the cam member 19 is in the first position, when the intermediate member 17 separates from the fulcrum member 13, the oil reservoir chamber 26
The oil of d passes through the communication hole 26b and the check valve 28, flows into the oil chamber 27, and flows into the second member 26.
slides away from the first member 25. Thereby, the intermediate member 17 is entirely expanded, and the first
With the pressure receiving part 25a of the member 25 in contact with the first cam surface 20a of the cam 20, the pressing part 2 of the second member 26
When the rod 6a comes into contact with the upper end of the rod portion 13b of the fulcrum member 13, the pressure in the oil chamber 27 increases and the flow of oil into the oil chamber 27 is stopped. Even if the intermediate member 17 is pressed from below by the rod portion 13b of the support member 13, the oil flowing into the oil chamber 27 does not flow back into the oil reservoir chamber 26d due to the action of the check valve 28, so that the intermediate member 17 is compressed. There's nothing to do,
The intermediate member 17 reliably maintains the state of contact with the fulcrum member 13.

Furthermore, a relief hole 25d is provided in the pressure receiving part 25a of the first member 25, and a part of the pressure receiving part 25a is provided below the pressure receiving part 25a (oil chamber 27).
A relief valve 30 is provided, which includes a ball 30a that projects upward from the relief hole 25a and can be seated in the relief hole 25d, and a spring 30b that biases the ball 30a in the seating direction. In addition, the cam member 19
When the pressure receiving part 2 is positioned at the first position,
A ball 30a is attached to the first cam surface 20a that contacts the ball 5a.
A recess 20 that allows the pressure receiving part 25a to protrude upward.
d is provided. As a result, when the cam member 19 is in the first position as shown in FIG. 6 (when the high-load intake valve 5b is in the operating state), the recess 20
d allows the ball 30a to protrude upward, and by keeping the relief valve 30 in the closed state and closing the relief hole 25d, the intermediate member 17 is maintained in contact with the fulcrum member 13. Functionality will be ensured.

On the other hand, as shown in FIG.
When the ball 30a is in the position (when the high-load intake valve 5b is inactive), the second cam surface 20b of the cam 20 pushes the ball 30a downward, and the relief valve 30 opens to open the relief hole 25d. is opened, the oil in the oil chamber 27 flows into the relief hole 2.
5d, and the pressure in the oil chamber 27 is relieved. That is, when the cam member 19 is in the second position, the intermediate member 17 is in the maximum extension state (the first member 25 rises due to the urging force of the spring member 18 and contacts the cam member 19, as shown in FIG. 8).
state in which the second member 26 is in contact with the retaining member 29)
However, the oil in the oil chamber 27 is leaking from the relief hole 25.
It is in a state where it can flow out via d. As a result, when the cam member 19 is switched from the second position to the first position (when the high-load intake valve 5b is switched from the non-operating state to the operating state), the intermediate member 17 is in the maximum extension state. Even if the fulcrum member 13 is brought into contact with the fulcrum member 13, it will easily contract, so if the fulcrum member 13 comes into contact with the fulcrum member 13 in its maximum extension state, the fulcrum will be lowered from its normal position and the high-load intake valve 5b will be inadvertently moved. This is to prevent the valve from opening.

In addition, in FIGS. 6 to 8, 13d, 1
3e is an oil hole provided in the fulcrum member 13 so that oil leaked into the fulcrum member 13 is supplied between the tip 13d of the fulcrum member 13 and the spherical recess 12a of the rocker arm 12; 12b is an oil hole provided in the rocker arm 12; This is an oil drain hole provided in the spherical recess 12a.

Next, the operation of the above embodiment will be explained.

During low-load operation of the engine, the cam member 19 assumes the second position as shown in FIG. 8, whereby the valve deactivation mechanism A operates and the high-load intake valve 5b becomes deactivated. The high-load intake valve 5b is held in a closed state by its valve spring 11, thereby closing the high-load intake port 3b. Further, the low-load intake valve 5a is controlled to open and close by the valve operating mechanism 8 as usual. Therefore, intake port 3 for low load
The combustion stability and combustion performance during low-load operation are improved by increasing the intake air flow rate and creating a strong intake air swirl in the cylinder 2.

On the other hand, during high load operation of the engine, the cam member 19 takes the first position as shown in FIG. Opening and closing are controlled by the valve mechanism 8. As a result, air is taken in from the high-load intake port 3b as well as the low-load intake port 3a, and as a result, the filling efficiency of the intake air is increased and the output during high-load operation is improved.

In this way, the dual induction intake system can be obtained by activating and inactivating the high-load intake valve 5b itself using the valve deactivation mechanism A, without providing a separate on-off valve. The structure can be simplified, and since the high-load intake valve 5b is kept inactive during low-load operation, engine drive loss can be reduced.

In addition, the valve inoperation mechanism A includes the Rocker arm 12.
The fulcrum member 13 constituting the fulcrum of the cam member 19
By moving back and forth in the same direction as the sliding direction of the fulcrum member 13, the fulcrum state and the floating state are directly changed via the intermediate member 17, so the high-load intake valve 5b can be activated from the inactive state. When switching to the state or vice versa, it is possible to perform the switching over multiple revolutions of the camshaft 9. Therefore, the above switching can always be carried out smoothly regardless of whether the engine is operating at low speed or high speed.

However, when the high-load intake valve 5b is inactive, the intermediate member 17
According to the movement of the cam surface 9a of the
Since the fulcrum member 13, which floats with the intermediate member 17, is separated from the fulcrum member 13 via the spring member 18 and does not respond, even if a hydraulic tappet structure as described above is used as the intermediate member 17, no pumping action is performed. This is advantageous in reducing engine drive loss.

Note that the present invention is not limited to the above-mentioned embodiments, but also includes various other modifications. That is, for example, in the above embodiment, an example was shown in which the valve deactivation mechanism A was applied to the high-load intake valve 5b in a dual induction intake system, but the present invention also applies to the operation of a specific cylinder of a multi-cylinder engine. It can also be applied to the case where the intake and exhaust valves are brought into an inoperable state in order to be stopped.

Further, in the above embodiment, the rocker arm 12 has one end connected to the camshaft 9 and the other end connected to the valve stem 5.
s and 6s, respectively, and swings using the intermediate part as a fulcrum, the present invention has one end as a fulcrum, the other end in contact with the valve stem, and the intermediate part in contact with the camshaft. It can also be applied to a Rocker arm system in which the arms are brought into contact with each other.

Further, in the above embodiment, the intermediate member 17 is a hydraulic tappet structure as described above, but a simple block body may also be used. However, the above-mentioned hydraulic tappet structure has better ability to maintain contact between the intermediate member 17 and the fulcrum member 13 and to follow the valve when the valve is in operation, and can suppress the valve clearance as small as possible. This is advantageous in reducing driving noise.

(Effects of the Invention) As described above, according to the present invention, the fulcrum member constituting the fulcrum of the rocker arm is directly changed between the fulcrum state and the floating state by the cam of the valve deactivation mechanism via the intermediate member. Even with a simple structure, the valve can be smoothly switched between the operating state and the inactive state, not only during low-speed operation but also during high-speed operation, and there is no pumping effect. Therefore, it is possible to reduce engine drive loss.

In addition, since a valve deactivation mechanism using a cam is used to switch the valve between the deactivated state and the activated state, even if the engine is a multi-cylinder engine, a single shaft extending in the longitudinal direction of the engine is required. By providing a cam on the shaft corresponding to each cylinder, it is possible to switch the valves of all cylinders between the operating state and the non-operating state with a simple structure and with one control force. .

[Brief explanation of drawings]

The drawings illustrate an embodiment in which the present invention is applied to a dual-induction type engine. 4 is a plan view of the rocker arm cover removed, FIG. 5a is a similar view to FIG. 4 with the rocker arm cover attached, and Figure b is a sectional view of the main part taken along line V-V in Figure 5a, Figure 6 is an enlarged view of the main part of the valve inoperation mechanism in Figure 1 in the operating state of the high-load intake valve, and Figure 7 6 is an enlarged detailed view of the intermediate member shown in FIG. 6, and FIG. 8 is a view similar to FIG. 6 when the high-load intake valve is in an inoperative state. 1...Cylinder head, 5a, 5b...Intake valve, 6...Exhaust valve, 9...Camshaft, 9a...
... cam surface, 12 ... rocker arm, 13 ... fulcrum member, 14 ... support member, 15 ... hydraulic tappet, 17 ... intermediate member, 18 ... spring member, 20 ... cam.

Claims (1)

[Claims] 1. In an engine having a plurality of cylinders, each cylinder has a valve deactivation mechanism, and each valve deactivation mechanism has an intake or exhaust valve that is constantly biased in the closing direction by a spring; A rocker arm that transmits the movement of the cam surface of the camshaft to the valve, a fulcrum member that is slidably supported on the engine fixed part and constitutes a fulcrum of the rocker arm, and a fulcrum member that is slidable in the same direction as the sliding direction of the fulcrum member. an intermediate member disposed, a spring member compressed between the fulcrum member and the intermediate member; and a spring member rotatably supported and in a first position, the intermediate member is moved toward the rocker arm side against the biasing force of the spring member. At the first cam surface and the second position, the intermediate member is pressed against the fulcrum member to put the valve in the actuated state, and the intermediate member is relatively separated from the fulcrum member by the biasing force of the spring member. a cam having a second cam surface for disabling the valve, the cam of each valve disabling mechanism being mounted on a shaft extending in the longitudinal direction of the engine;
An engine valve deactivation device characterized in that it is installed corresponding to each cylinder.