JP2011196266A - Variable valve gear of internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a variable valve gear capable of sensing the valve stopped and returned conditions without installing sensors at all cylinders or all valves.SOLUTION: The variable valve gear includes a transmitting member installed at least on each of two cylinders in a position between a cam and a valve and transmitting the acting force of the cam to the valve, and a changeover mechanism to change over the valve opening characteristics of the valves installed on the at least two cylinders, by changing the operating condition of the transmitting member, wherein the changeover mechanism is furnished with an actuator used commonly in at least two cylinders and changing over the operating condition of each transmitting member of the at least two cylinders, and a rigid member to make displacement in association with the motion of the actuator and change over the operating condition of each transmitting member. Further the variable valve gear is equipped with a sensor to sense the displacement of the rigid member and can sense the opening characteristics of the currently working valve in accordance with the sensed displacement of the rigid member.

Description

  The present invention relates to a variable valve operating apparatus for an internal combustion engine.

  For example, Patent Literature 1 discloses a variable valve mechanism that switches the lift of intake valves or exhaust valves of all cylinders by a pneumatic actuator. This variable valve mechanism includes two types of cams, a low speed small cam and a high speed large cam for each cylinder, a low speed rocker arm that contacts the small cam, and a high speed rocker arm that contacts the large cam. It has two types of rocker arms. Lock pins that can be pushed by a control plate are attached to the low-speed rocker arm and the high-speed rocker arm.

  When the lock pin is not pushed in this variable valve mechanism, the high speed rocker arm and the low speed rocker arm are separated, and the intake valve (or exhaust valve) is moved by the small cam through the low speed rocker arm. Lifted. On the other hand, when the lock pin is pushed, the lock pin is engaged with the high speed rocker arm, and the low speed rocker arm and the high speed rocker arm are connected to each other. At this time, the intake valve (or exhaust valve) is lifted by the large cam via the connected rocker arm.

  In the variable valve mechanism of Patent Document 1, connection / separation of the high-speed and low-speed rocker arms is performed by pushing a lock pin, and the lock pin is pushed by a control plate attached to a control rod. Done. When the gas pressure actuator is actuated, the control rod moves in the specified axial direction due to negative pressure. When the control rod moves, the lock pin is pushed and the rocker arm for high speed and low speed is connected. To do. On the other hand, when the negative pressure of the gas pressure actuator is released, the control rod and control plate are pushed back into place, so the lock pin is disengaged and the rocker arm for high speed and low speed is separated. It will be in the state. By this switching mechanism, the lift amount of the intake valve (or exhaust valve) is switched.

JP 2002-242628 A JP 07-119424 A

  When switching the lift amount of the intake valve or the exhaust valve as in Patent Document 1 or performing control for switching valve stop / return, for example, a cylinder pressure sensor is attached to each cylinder to sense a cylinder pressure change, Alternatively, the valve stop / return state for each cylinder is determined by detecting a change in stress by attaching a strain gauge or the like to each valve.

  However, if sensors or the like are attached to each cylinder or valve, the attachment positions of the sensors and the like are close to each other. Also, the inside of the cylinder is affected by the combustion chamber. Therefore, in terms of securing the installation position, the number of installation processes, and cost, the installation for each cylinder and each valve is often difficult.

  Moreover, even when a plurality of valve stops / returns are performed by one shaft (control rod) as in the technique of Patent Document 1 described above, even if a failure of valve stop / return is detected, the failure It is difficult to determine whether the cause of this is an abnormality in the shaft or an abnormality in a mechanism for each cylinder such as a valve or a rocker arm.

  The present invention has been made to solve the above-described problems, and provides an improved variable valve operating system for an internal combustion engine that can accurately detect the valve stop / return state with a simpler system. The purpose is to do.

A first invention is a variable valve operating apparatus for an internal combustion engine,
A transmission member disposed between the cam and the valve in each of at least two cylinders, and transmitting the acting force of the cam to the valve;
A mechanism for switching valve opening characteristics of the valves provided in the at least two cylinders by changing an operation state of the transmission member; and
An actuator that is shared by the at least two cylinders and is driven when switching the operation state of the transmission member in the at least two cylinders;
A switching mechanism including a rigid member that is displaced in accordance with the operation of the actuator and switches an operation state of the transmission member provided in the at least two cylinders;
A sensor for detecting the displacement of the rigid member;
Detecting means for determining a valve opening characteristic of the valve in accordance with the detected displacement of the rigid member;
Is provided.

According to a second invention, in the first invention,
The transmission member includes a first rocker arm that swings in synchronization with the cam, and a second rocker arm that can push the valve.
The rigid member is
A member connecting shaft disposed inside the rocker shaft supporting the first rocker arm and the second rocker arm so as to be displaceable in an axial direction;
Displacement that is disposed in each of the cylinders, is connected to the member connecting shaft, and is displaced together with the member connecting shaft in accordance with the operation of the actuator, thereby changing the operation state of the second rocker arm in each of the cylinders. A member, and
The switching mechanism is movably disposed in a pin hole formed in each of the first rocker arm and the second rocker arm, and is displaced in conjunction with displacement of the displacement member, whereby the first rocker arm And a switching pin for switching between a connected state in which the second rocker arm is connected and an unconnected state in which the connection is released,
The sensor is disposed inside the rocker shaft and detects the displacement of the rigid member by detecting the displacement of the member connecting shaft.
It is characterized by that.

According to a third invention, in the first invention,
The internal combustion engine has a first cylinder group composed of a plurality of cylinders arranged adjacent to each other and a second cylinder group composed of a plurality of cylinders arranged adjacent to each other, and the plurality of cylinders belonging to the first cylinder group The explosion order is set so that there is a common base circle section of the cam for the cylinders and a common base circle section of the cam for the plurality of cylinders belonging to the second cylinder group. ,
The rigid member is
A first rigid member that switches an operating state of the transmission member of a cylinder belonging to the first cylinder group;
A second rigid member that switches an operating state of the transmission member of a cylinder belonging to the second cylinder group,
The switching mechanism includes a delay mechanism that delays the displacement of the second rigid member when the actuator is operated,
The sensor detects the displacement of the first rigid member and the displacement of the second rigid member, respectively.
The detecting means discriminates the valve opening characteristics of the cylinders belonging to the first cylinder group according to the displacement of the first rigid body member, and applies the second cylinder group according to the displacement of the second rigid body member. It is characterized by determining the valve opening characteristics of the valve of the cylinder to which it belongs.

According to a fourth invention, in the third invention,
The transmission member includes a first rocker arm that swings in synchronization with the cam, and a second rocker arm that can push the valve.
The first rigid member and the second rigid member are respectively
A member connecting shaft disposed inside the rocker shaft supporting the first rocker arm and the second rocker arm so as to be displaceable in an axial direction;
Displacement that is disposed in each of the cylinders, is connected to the member connecting shaft, and is displaced together with the member connecting shaft in accordance with the operation of the actuator, thereby changing the operation state of the second rocker arm in each of the cylinders. A member, and
The switching mechanism is movably disposed in a pin hole formed in each of the first rocker arm and the second rocker arm, and is displaced in conjunction with displacement of the displacement member, whereby the first rocker arm And a switching pin for switching between a connected state in which the second rocker arm is connected and an unconnected state in which the connection is released,
The sensor is disposed inside the rocker shaft, detects the displacement of the rigid member by detecting the displacement of the member connecting shaft,
The delay mechanism is interposed in the rocker shaft in the middle of the member connecting shaft.

  In the first invention, the rigid member is displaced in accordance with the driving of the actuator, thereby switching the operating state of the transmission member provided in each cylinder, thereby switching the valve opening characteristics. Here, 1st invention has a sensor which detects the displacement of a rigid body member. Thereby, even if it does not install a sensor for every cylinder or every valve, the valve opening characteristic of the valve of each cylinder can be discriminated by detecting the displacement of a rigid member.

  In the third invention, the rigid member includes a first rigid member corresponding to the first cylinder group and a second rigid member corresponding to the second cylinder group. Also. When the actuator is operated, the displacement of the second rigid member is delayed by the delay mechanism. Therefore, the valve opening characteristics of the cylinders belonging to the first cylinder group may differ from the valve opening characteristics of the cylinders belonging to the second cylinder group. In this regard, in the third invention, the sensor can detect the displacement of the first rigid member and the displacement of the second rigid member, respectively. Thereby, the valve opening characteristics of the cylinders belonging to the first cylinder group according to the displacement of the first rigid member, and the valve opening characteristics of the cylinders belonging to the second cylinder group according to the displacement of the second rigid member, Each can be distinguished.

  In the second and fourth inventions, the sensor is disposed inside the rocker shaft, and detects the displacement of the rigid member by detecting the displacement of the member connecting shaft. Here, it is considered that there are few moving parts other than the displacement member inside the rocker shaft, and there is little foreign matter mixed into the rocker shaft. Therefore, according to the second or fourth invention, it is possible to detect the displacement of the member connecting shaft (that is, the rigid member) more accurately.

1 is a diagram schematically showing an overall configuration of a variable valve operating apparatus for an internal combustion engine according to a first embodiment of the present invention.

Embodiment.
Hereinafter, an embodiment of the present invention will be described with reference to FIG.
[Configuration of variable valve gear]
FIG. 1 is a diagram schematically showing an overall configuration of a variable valve operating apparatus 10 for an internal combustion engine according to a first embodiment of the present invention. FIG. 1 is a plane including an axis of a rocker shaft 22 and an axis of switching pins 36, 38, and 44, which will be described later. FIG. The internal combustion engine of the present embodiment is an in-line four-cylinder engine having four cylinders (# 1 to # 4) and performing an explosion stroke in the order of # 1, # 3, # 4, and # 2. Each cylinder of the internal combustion engine is provided with two intake valves and two exhaust valves, and the variable valve apparatus 10 includes two intake valves or two exhaust valves disposed in each cylinder. It functions as a driving mechanism.

  The variable valve operating apparatus 10 includes a camshaft 12. The camshaft 12 is connected to a crankshaft (not shown) by a timing chain or a timing belt, and is configured to rotate at a half speed of the crankshaft. The camshaft 12 is provided with one main cam 14 and one sub cam 16 per cylinder. The main cam 14 includes an arc-shaped base circle portion coaxial with the camshaft 12 and a nose portion formed so as to bulge a part of the base circle outward in the radial direction. In the present embodiment, the sub cam 16 is configured as a cam having only a base circle (zero lift cam).

  Each cylinder of the internal combustion engine is provided with rocker arms 18 and 20 as transmission members for transmitting the acting force of the main cam 14 to the valve of the cylinder so as to be interposed between the cams 14 and 16 and the valve. Yes. More specifically, a first rocker arm 18 and a second rocker arm 20 are provided adjacent to each other for each cylinder, and are supported by a single rocker shaft 22 so as to be rotatable (oscillated). .

  A cam roller 26 is rotatably attached to the first rocker arm 18. The first rocker arm 18 is biased by a coil spring (not shown) attached to the rocker shaft 22 so that the cam roller 26 is always in contact with the main cam 14. On the other hand, the second rocker arm 20 is an arm that drives two valves, and is configured to surround the first rocker arm 18.

  A first pin hole 32a concentric with the cam roller 26 is formed in the support shaft 30 of the cam roller 26. Two holes are formed in the second rocker arm 20 at positions corresponding to the first pin holes 32a. Second pin holes 32L and 32R are formed. The centers of these pin holes 32a, 32L, 32R are arranged in the same arc shape with the rocker shaft 22 being the rotation center of the rocker arms 18, 20 as the center. Further, when the cam roller 26 is in contact with the base circle of the main cam 14 and the second rocker arm is in contact with the base circle of the sub cam 16, the position of the first pin hole 32a and the second pin hole 32L. , 32R coincide with each other.

  A cylindrical switching pin 36 is movably inserted into the first pin hole 32a. A cylindrical switching pin 38 that contacts the switching pin 36 is movably inserted into the second pin hole 32L (left side in FIG. 1). The second pin hole 32L into which the switching pin 38 is inserted is closed at the end opposite to the first rocker arm 18 by the cap 40, and the switching pin 38 is inserted into the first rocker arm inside the second pin hole 32L. A return spring 42 is disposed to urge toward 18 directions (hereinafter referred to as “advance direction”). A cylindrical switching pin 44 that is in contact with the switching pin 36 is movably inserted into the second pin hole 32R (right side in FIG. 1).

  In the # 4 cylinder, a first link arm 46 (displacement member) that contacts the switching pin 44 is disposed on the side (right side in FIG. 1) of the second rocker arm 20. A protrusion 46 a is provided at the tip of the first link arm 46. On the other hand, in the # 1 to # 3 cylinders, a second link arm 48 (displacement member) that contacts the switching pin 44 is disposed on the side of the second rocker arm 20 (right side in FIG. 1). The first link arm 46 and the second link arm 48 are supported by one rocker shaft 22.

  The rocker shaft 22 is formed in a hollow shape. Inside the rocker shaft 22, a link shaft 50 (member connecting shaft) is inserted in a state displaceable in the axial direction. A first link arm 46 and a second link arm 48 are fixed to the link shaft 50. The link shaft 50, the first link arm 46, and the second link arm 48 are configured to be able to be displaced in conjunction with the axial direction without being blocked by the rocker shaft 22.

  Here, the link shaft 50 is divided into a first link shaft 50a on the # 3 and # 4 cylinder side and a second link shaft 50b on the # 1 and # 2 cylinder side. The first link shaft 50 a and the second link shaft 50 b are connected via a delay mechanism 52.

  The delay mechanism 52 includes an intra-delay mechanism link shaft 54 having an abutting portion 54a that abuts the second link shaft 50b at one end. The contact portion 54a is formed with a larger diameter than other portions. The other end side of the in-delay mechanism link shaft 54 is inserted into a hollow first link shaft 50a.

  The delay mechanism 52 includes a delay mechanism spring 56 whose spring length is defined between the abutment portion 54a of the in-delay mechanism link shaft 54 and the end portion of the first link shaft 50a on the delay mechanism 52 side. ing. A slot (not shown) is formed in a portion of the first link shaft 50a that receives the insertion of the in-delay link shaft 54. A stroke limiting pin (not shown) press-fitted into the delay mechanism internal link shaft 54 is engaged with the long hole, and the delay mechanism internal link shaft 54 has a range in which the stroke limiting pin is regulated by the long hole. It can move in the axial direction.

  A movement detection sensor 60a is installed in the rocker shaft 22 so as to face the end portion on the # 4 cylinder side of the first link shaft 50a. On the other hand, a movement detection sensor 60b is installed so as to face the end of the second link shaft 50b on the # 1 cylinder side. In the present embodiment, both movement detection sensors 60a and 60b are both magnetic sensors.

  In the camshaft 12, a columnar portion 12 a formed in a columnar shape is formed at a portion facing the protruding portion 46 a provided on the first link arm 46. A spiral guide rail 62 extending in the circumferential direction is formed on the outer peripheral surface of the cylindrical portion 12a. Here, the guide rail 62 is formed as a spiral groove.

  This variable valve operating apparatus 10 includes an electromagnetic solenoid 64 as an actuator that generates a driving force for engaging (inserting) the protrusion 46 a with the guide rail 62. The electromagnetic solenoid 64 is disposed at a position where the drive shaft can press the pressing surface of the first link arm 46 toward the guide rail 62, and is fixed to the cam carrier (or cylinder head).

  The ECU 66 is an electronic control unit (ECU) 66 for controlling the operating state of the internal combustion engine. The ECU 66 is electrically connected to the electromagnetic solenoid 64, for example, and controls the duty of the electromagnetic solenoid 64 by issuing a control signal. Further, the ECU 66 is electrically connected to, for example, the movement detection sensors 60a and 60b, and receives the outputs of these sensors as inputs, and can detect the positions of the first link shaft 50a and the second link shaft 50b.

[Operation of variable valve mechanism]
(When the valve is operating)
When the valve is operating, the electromagnetic solenoid 64 is turned off. In this state, the first link arm 46 is separated from the camshaft 12 and is positioned at the displacement end Pmax1 under the urging force of the return spring 42. The link shaft 50 and the second link arm 48 connected thereto are displaced in conjunction with the first link arm 46. Therefore, the first link arm 46 and the second link arm 48 are located on the advancing direction side (right side in FIG. 1).

  At this time, since the force against the urging force of each return spring 42 is not acting, the switching pin 36 is inserted into both the pin holes 32a and 32R, and the switching pin 38 is inserted into both the pin holes 32a and 32L. It is in the state. As a result, the first rocker arm 18 and the second rocker arm are connected by the switching pins 36 and 38.

  In a state where the first rocker arm 18 and the second rocker arm 20 are connected, the first rocker arm 18 and the second rocker arm 20 are rocked by the acting force of the main cam 14 received by the first rocker arm 18. Move. Accordingly, the acting force of the main cam 14 is transmitted to both valves via the first rocker arm 18 and the second rocker arm 20. That is, a normal valve lift operation is performed according to the profile of the main cam 14.

(Valve stop control)
The valve stop operation is performed, for example, when a request for executing a predetermined valve stop operation such as a fuel cut request of the internal combustion engine is detected by the ECU 66. Here, in the internal combustion engine in which the explosion order of the cylinders is in the order of # 1 → # 3 → # 4 → # 2 as in the present embodiment, the base circle section (valve of the main cam 14 with respect to the # 3 and # 4 cylinders) There is a common section where there is no lift. When a valve stop operation request is issued, energization of the electromagnetic solenoid 64 is turned on at the timing when the common base circle section # 3 and # 4 arrives.

  As a result, the first link arm 46 rotates about the rocker shaft 22, and the protrusion 46 a engages with the guide rail 62. As a result, the protrusion 46a is guided by the guide rail 62, and the first link arm 46 moves toward the displacement end Pmax2 using the rotational force of the camshaft 12. Further, in conjunction with the movement of the first link arm 46, the second link arm 48 of the # 3 cylinder connected to the first link shaft 50a and the first link shaft 50a moves.

  When the first link arm 46 reaches the displacement end Pmax2, the force against the return spring 42 acts on the # 3 and # 4 cylinders due to the displacement of the second link arm 48 of the first link arm 46 and the # 3 cylinder. Therefore, the switching pins 36 and 38 are returned into the pin holes 32a and 32L, respectively. As a result, the first rocker arm 18 and the second rocker arm 20 are immediately disconnected. As a result, the acting force of the main cam 14 is transmitted only to the first rocker arm 18 and is not transmitted to the second rocker arm 20. At this time, the secondary cam 16 comes into contact with the second rocker arm 20, but since the secondary cam 16 is a zero lift cam, the second rocker arm 20 is in a stationary state, and the lift operation of the valve is in the closed position. It will be in a stopped state.

  On the other hand, in the common base circle section of the # 3 and # 4 cylinders, at least one first rocker arm 18 of the # 1 or # 2 cylinder is rocked by the main cam 14. Therefore, in the cylinders in which the first rocker arm 18 is swinging among the # 1 and # 2 cylinders, the second rocker that receives the urging force from the first rocker arm 18 driven by the main cam 14 and the valve spring is used. A shearing force generated by both the rocker arm 20 and the rocker arm 20 acts on the switching pins 36 and 38. As a result, the frictional force (sliding resistance) generated between the switching pins 36, 38 and the pin holes 32a, 32L, 32R is larger than that during the non-oscillating operation of the first rocker arm 18.

  Here, the spring load of the delay mechanism spring 56 is a frictional force (sliding force) generated between the switching pins 36 and 38 and the pin holes 32a, 32L and 32R when the rocker arms 18 and 20 swing (when the valve is lifted). (Dynamic resistance) is set to be smaller. Therefore, even when the first link shaft 50a is displaced along with the displacement of the first link arm 46, the second link shaft 50b is not yet displaced in conjunction with the displacement of the first link shaft 50a, and the delay mechanism spring 56 is not displaced. Is in a contracted state.

  In the state where the delay mechanism spring 56 is contracted, when the swing operation (valve lift operation) of the first rocker arm 18 of the # 1 cylinder is finished, the common base circle section of the main cam 14 for the # 1 and # 2 cylinders arrives. To do. When this common base circle section arrives, the frictional force generated between the switching pins 36, 38 and the pin holes 32a, 32L, 32R in the # 1 or # 2 cylinder is reduced. Further, the spring load of the delay mechanism spring 56 is set to be larger than the total value of the spring loads of the return springs 42 arranged in the # 1 and # 2 cylinders. Accordingly, the second link shaft 50b carrying the # 1 cylinder and the # 2 cylinder is displaced. Along with this displacement, the second link arms 48 of the # 1 and # 2 cylinders are displaced, whereby the switching pins 36 and 38 are returned into the pin holes 32a and 32L, respectively. As a result, the first rocker arm 18 and the second rocker arm 20 are immediately disconnected from each other, and the lift operation of the valve is stopped at the closed position for the # 1 and # 2 cylinders.

(Valve return operation)
The valve return operation for returning from the valve stop state to the valve operation state is performed, for example, when an execution request for a predetermined valve return operation such as a return request from a fuel cut is detected by the ECU 66. Such a valve return operation is started by turning off the energization of the electromagnetic solenoid 64 at a predetermined timing. When energization of the electromagnetic solenoid 64 is turned off, the protrusion 46 a of the first link arm 46 is removed from the guide rail 62. As a result, the force that keeps the switching pins 36 and 38 in the pin holes 32a and 32L against the urging force of the return spring 42 disappears. As a result, the switching pins 36 and 38 are moved in the advancing direction by the urging force of the return spring 42, and the first rocker arm 18 and the second rocker arm 20 are connected via the switching pins 36 and 38, that is, Thus, the valve can be lifted by the acting force of the main cam 14. Further, as the switching pins 36 and 38 move in the advance direction by the urging force of the return spring 42, the first link arm 46 and the link shaft 50 and the second link arm 48 to be connected are connected via the switching pin 44. Is returned from the displacement end Pmax2 to the displacement end Pmax1.

[Valve return / valve stop detection]
In the present embodiment, movement of the first link shaft 50a and movement of the second link shaft 50b can be detected by the movement detection sensors 60a and 60b installed at both ends in the rocker shaft 22, respectively. .

  As described above, the first and second link shafts 50a and 50b switch the valve stop / return states of the respective cylinders, and the positions of the first link shaft 50a and the second link shaft 50b and corresponding to them. The stop / return states of the cylinder valves are linked. Table 1 below explains the relationship between the clearances of the first link shaft 50a and the second link shaft 50b and the corresponding movement detection sensors 60a and 60b, and the state of the valves.

  As shown in Table 1, when the first link shaft 50a approaches the movement detection sensor 60a side and the clearance is smaller than a predetermined value, the distance between the movement detection sensor 60a and the first link shaft 50a is displaced to a close position. is doing. That is, the first link arm 46 connected to the first link shaft 50a is at a position corresponding to the displacement end Pmax1. At this time, as described above, the # 3 and # 4 cylinders carried by the first link shaft 50a are in the connected state and are determined to be in the valve operating state.

  On the other hand, when the first link shaft 50a is separated from the movement detection sensor 60a and the clearance between both is larger than a predetermined value, the first link shaft 50a is in a position where the first link arm 46 corresponds to the displacement end Pmax2. . At this time, as described above, the # 3 and # 4 cylinders carried by the first link shaft 50a are determined to be in the disconnected state and in the valve stop state.

  Similarly, when the second link shaft 50b approaches the movement sensor 60b and the clearance is smaller than a predetermined value, the second link arm 48 connected to the second link shaft 50b exerts a force to push the return spring 42 back. Is determined to be in a position to perform. That is, it is determined that the # 1 and # 2 cylinders carried by the second link shaft 50b are in a valve stop state (non-connected state). On the other hand, when the clearance between the second link shaft 50b and the movement detection sensor 60b is larger than a predetermined value, the second link shaft 50b is in a position where the second link arm 48 to be connected does not generate a force against the return spring. It is judged that there is. That is, it is determined that the # 1 and # 2 cylinders are in the valve return state (connected state).

  The ECU 66 stores the relationship shown in Table 1 in advance. During the control of the internal combustion engine, the ECU 66 detects the clearance between the movement detection sensor 60a and the first link shaft 50a or the movement detection sensor 60b and the second link shaft 50b from the outputs of the movement detection sensors 60a and 60b. Is determined to be smaller than or larger than a predetermined value serving as a discrimination criterion, and the valve states of the cylinder groups of # 1 and # 2 cylinders and the valve states of # 3 and # 4 are detected, respectively. Moreover, when the clearance detected at this time does not become larger or smaller than a predetermined value of the discrimination criterion, it can be detected as an abnormality of the link shafts 50a and 50b.

  As described above, in this embodiment, the movement of the two link shafts 50a and 50b can be detected by the movement detection sensors 60a and 60b provided before and after the link shaft 50. Accordingly, it is possible to accurately determine the valve stop / return state that is switched by the displacement of each link shaft 50a, 50b. Thereby, the valve state of each cylinder can be detected without installing a sensor for each cylinder or each valve.

  The movement detection sensors 60 a and 60 b are disposed inside the rocker shaft 22 that houses the link shaft 50. In the rocker shaft 22, there are few operating parts other than the link shaft 50, and foreign matter is not mixed. Therefore, the displacement of each link shaft 50a, 50b can be detected more accurately, and the valve return / valve stop state can be detected more accurately.

  In this embodiment, the case where the link shaft 50 is divided into the first link shaft 50a and the second link shaft 50b and the delay mechanism 52 is interposed between them is described. However, the present invention is not limited to this, and connection / disconnection of all cylinders may be switched at a time by one link shaft. In this case, the connection / disconnection state of the entire cylinder can be detected by installing a movement detection sensor that detects the position of the link shaft at one end.

  Further, in the present embodiment, the case where the movement detection sensors 60a and 60b are magnetic sensors has been described. However, in the present invention, the sensor is not limited to this, and other sensors may be used as long as they can detect the movement of the link shaft 50, such as a stroke sensor, a sound sensor, and a stress sensor.

  In the present embodiment, the case where the valve return / valve stop state is detected as the valve opening characteristic has been described. However, the present invention is not limited to this, and the connection state and the non-connection state of the first and second rocker arms 18 and 20 can be detected by the movement detection sensors 60a and 60b. That is, with this device, the valve is opened / closed by the acting force of the main cam 14 (connected state), or the second rocker arm 20 is swung by the acting force of the sub cam 16, thereby opening and closing the valve. It is possible to detect whether it is in a connected state (connected state). Therefore, for example, when a small cam having a lift amount smaller than that of the main cam 14 is used instead of the zero lift cam as the auxiliary cam, the valve opening characteristic by the main cam is similarly determined. It is possible to detect whether the valve opening characteristic is obtained.

  In the above embodiment, when referring to the number of each element, quantity, quantity, range, etc., the reference is made unless otherwise specified or the number is clearly specified in principle. The invention is not limited to the numbers. Further, the structure and the like described in this embodiment are not necessarily essential to the present invention unless otherwise specified or clearly specified in principle.

DESCRIPTION OF SYMBOLS 10 Variable valve apparatus 12 Cam shaft 12a Cylindrical part 14 Main cam 16 Sub cam 18 1st rocker arm 20 2nd rocker arm 22 Rocker shaft 26 Cam roller 30 Support shaft 32a, 32L, 32R Pin hole 36, 38, 44 Switching pin 40 Cap 42 Return spring 46 1st link arm 48 2nd link arm 50 Link shaft 50a 1st link shaft 50b 2nd link shaft 52 Delay mechanism 54 Delay mechanism internal link shaft 56 Delay mechanism spring 60a, 60b Movement detection sensor 62 Guide rail 64 Electromagnetic solenoid 66 ECU

Claims (4)

A transmission member disposed between the cam and the valve in each of at least two cylinders, and transmitting the acting force of the cam to the valve;
A mechanism for switching valve opening characteristics of the valves provided in the at least two cylinders by changing an operation state of the transmission member; and
An actuator that is shared by the at least two cylinders and is driven when switching the operation state of the transmission member in the at least two cylinders;
A switching mechanism including a rigid member that is displaced in accordance with the operation of the actuator and switches an operation state of the transmission member provided in the at least two cylinders;
A sensor for detecting the displacement of the rigid member;
Detecting means for determining a valve opening characteristic of the valve in accordance with the detected displacement of the rigid member;
A variable valve operating apparatus for an internal combustion engine, comprising: The transmission member includes a first rocker arm that swings in synchronization with the cam, and a second rocker arm that can push the valve.
The rigid member is
A member connecting shaft disposed inside the rocker shaft supporting the first rocker arm and the second rocker arm so as to be displaceable in an axial direction;
Displacement that is disposed in each of the cylinders, is connected to the member connecting shaft, and is displaced together with the member connecting shaft in accordance with the operation of the actuator, thereby changing the operation state of the second rocker arm in each of the cylinders. A member, and
The switching mechanism is movably disposed in a pin hole formed in each of the first rocker arm and the second rocker arm, and is displaced in conjunction with displacement of the displacement member, whereby the first rocker arm And a switching pin for switching between a connected state in which the second rocker arm is connected and an unconnected state in which the connection is released,
The sensor is disposed inside the rocker shaft and detects the displacement of the rigid member by detecting the displacement of the member connecting shaft.
The variable valve operating apparatus according to claim 1. The internal combustion engine has a first cylinder group composed of a plurality of cylinders arranged adjacent to each other and a second cylinder group composed of a plurality of cylinders arranged adjacent to each other, and the plurality of cylinders belonging to the first cylinder group The explosion order is set so that there is a common base circle section of the cam for the cylinders and a common base circle section of the cam for the plurality of cylinders belonging to the second cylinder group. ,
The rigid member is
A first rigid member that switches an operating state of the transmission member of a cylinder belonging to the first cylinder group;
A second rigid member that switches an operating state of the transmission member of a cylinder belonging to the second cylinder group,
The switching mechanism includes a delay mechanism that delays the displacement of the second rigid member when the actuator is operated,
The sensor detects the displacement of the first rigid member and the displacement of the second rigid member, respectively.
The detecting means discriminates the valve opening characteristics of the cylinders belonging to the first cylinder group according to the displacement of the first rigid body member, and applies the second cylinder group according to the displacement of the second rigid body member. The valve opening characteristic of the valve of the cylinder to which it belongs is discriminate | determined. The transmission member includes a first rocker arm that swings in synchronization with the cam, and a second rocker arm that can push the valve.
The first rigid member and the second rigid member are respectively
A member connecting shaft disposed inside the rocker shaft supporting the first rocker arm and the second rocker arm so as to be displaceable in an axial direction;
Displacement that is disposed in each of the cylinders, is connected to the member connecting shaft, and is displaced together with the member connecting shaft in accordance with the operation of the actuator, thereby changing the operation state of the second rocker arm in each of the cylinders. A member, and
The switching mechanism is movably disposed in a pin hole formed in each of the first rocker arm and the second rocker arm, and is displaced in conjunction with displacement of the displacement member, whereby the first rocker arm And a switching pin for switching between a connected state in which the second rocker arm is connected and an unconnected state in which the connection is released,
The sensor is disposed inside the rocker shaft, detects the displacement of the rigid member by detecting the displacement of the member connecting shaft,
The variable valve operating apparatus according to claim 3, wherein the delay mechanism is interposed in the rocker shaft in the middle of the member connecting shaft.

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