JP4770874B2 - Variable valve mechanism for internal combustion engine - Google Patents

Description

  The present invention relates to a variable valve mechanism for an internal combustion engine that varies the open / close characteristics of an intake valve or an exhaust valve of the internal combustion engine.

  2. Description of the Related Art A variable valve mechanism that makes a lift amount and a working angle of an intake valve and an exhaust valve variable according to an operating state of an internal combustion engine is known. Among them, there is known one in which a swing cam is provided coaxially with a rotating cam interlocking with a crankshaft, and the rotating cam and the swing cam are connected by a complicated link mechanism. A control shaft is provided in the middle of this complicated link. The phase of the swing cam can be changed by displacing the swing center of the arm constituting a part of the link by this control shaft. The lift amount and the operating angle are made variable by changing the phase of the swing cam. As a result, fuel efficiency can be improved and stable drivability can be achieved at low speed and low load, and intake efficiency can be improved and sufficient output can be ensured at high speed and high load. (See Patent Document 1).

  However, in order to link the rotating cam and the swing cam that exist coaxially in this way, the link mechanism has to be long and complicated. For this reason, there is a possibility that the certainty and reliability of operation in the variable valve mechanism are lacking. Therefore, a technique related to a variable valve mechanism for an internal combustion engine that realizes reliable operation and reliability without providing a long and complicated link mechanism, and a technique related to an intake air amount control device using this variable valve mechanism is disclosed. (See Patent Document 2).

The variable valve mechanism of the internal combustion engine disclosed in the above publication is characterized in that the intake and exhaust valves are opened and closed via an intermediate drive mechanism supported by a shaft different from the rotating cam interlocked with the crankshaft. Specifically, the intermediary drive mechanism is coaxially provided with an input portion that comes into contact with the rotating cam and an output portion that comes into contact with a rocker arm that opens and closes the intake and exhaust valves, and the input portion is driven by the rotating cam. The intake and exhaust valves are opened and closed via the output unit. Here, it is possible to continuously adjust the lift amount and operating angle of the intake / exhaust valve by relatively changing the phases of the input part and the output part of the mediation drive mechanism.
JP-A-11-324625 JP 2001-263015 A

  By the way, in the variable valve mechanism of the internal combustion engine described above, the input part and the output part of the intermediate drive mechanism are configured coaxially on an axis different from that of the rotating cam, so that a long and complicated link mechanism can be provided without being provided. Realizes reliable operation and reliability. However, in this configuration, since the phase of the input portion with respect to the rotating cam is always constant, the lift amount and working angle of the intake and exhaust valves that are opened and closed by the variable valve mechanism can be adjusted, but the valve timing is adjusted. It is difficult to do arbitrarily. Therefore, in order to obtain the required valve timing, a lift phase and a working angle are adjusted by the intermediate drive mechanism, and a valve phase variable mechanism that can adjust the valve timing separately is required. The system becomes complicated.

  Accordingly, the present invention has been made in view of the above-described problems, and by making it possible to adjust the lift amount and valve timing of a valve with a single drive device (actuator), a variable valve for an internal combustion engine is provided. The purpose is to make the mechanism system simple.

  The present invention employs the following means in order to solve the above-described problems. That is, a variable valve mechanism for an internal combustion engine that opens and closes an intake / exhaust valve by a four-bar linkage mechanism having an input portion that contacts a rotationally driven rotating cam and an output portion that opens and closes the intake / exhaust valve, It is means for controlling the opening and closing characteristics of the intake and exhaust valves by controlling the attitude of the four-bar linkage mechanism and changing the relative position between the rotary cam and the input unit. Specifically, the variable valve of the internal combustion engine is provided with a rotary cam that is driven to rotate, and the open / close characteristic of at least one of an intake valve and an exhaust valve that is opened and closed by the rotary cam is variable by a variable valve transmission mechanism. The variable valve transmission mechanism includes an input arm having an input portion that contacts the rotating cam, a transmission arm that is swingably connected to the input arm, and a swingable mechanism with the transmission arm. A swing arm that is connected and swingable around a rotation control shaft and transmits a driving force transmitted from the rotation cam to an output unit that opens and closes the valve, and rotates about the rotation control shaft. A four-bar linkage mechanism configured to drive and control arm that is swingably connected to the input arm, and controls the attitude of the four-bar link mechanism, Rolling by changing the relative position between the cam and the input portion, characterized by having a valve opening and closing control means for controlling the opening and closing characteristics of the valve.

  In the variable valve mechanism of the internal combustion engine configured as described above, the variable valve transmission mechanism is a four-bar linkage mechanism including an input arm, a transmission arm, a swing arm, and a control arm. The provided input unit is driven by the rotating cam, and the output unit is driven via the variable valve transmission mechanism, thereby opening and closing the valve. That is, when the input unit is driven by the rotating cam in a state where the control arm is fixed, the output unit swings through the transmission arm and the swinging arm, and the opening / closing control of the valve is performed. Further, in this variable valve mechanism of the internal combustion engine, the relative position between the input portion and the rotary cam can be changed by the valve opening / closing control means to control the opening / closing characteristics of the valve. That is, by changing the relative position between the input unit and the rotating cam, the phase of the input unit with respect to the rotating cam is changed relatively, thereby adjusting the valve timing of the valve opened and closed by the variable valve mechanism. It becomes possible to do.

  On the other hand, by changing the relative position between the input unit and the rotating cam, the posture of the link mechanism including the input arm, the transmission arm, the swing arm, and the control arm is changed. Along with this, the displacement amount of the output part that opens and closes the valve also fluctuates in conjunction with it, and the lift amount of the valve also fluctuates. As described above, by controlling the attitude of the four-bar linkage mechanism in the variable valve mechanism by changing the relative position between the input unit and the rotary cam, the valve timing phase and the valve lift amount, which are the valve opening / closing characteristics, can be simultaneously adjusted. It becomes possible to control. In addition, by controlling the attitude of the four-bar linkage mechanism with one drive device (actuator), the valve timing phase and the valve lift amount, which are the valve opening / closing characteristics, are controlled with one actuator.

  Note that the valve timing phase and the control amount of the valve lift amount are affected by the dimensions of the input arm, transmission arm, swing arm and control arm constituting the four-bar linkage mechanism. It is desirable to configure the link mechanism with a dimension corresponding to the lift amount of the valve.

  The variable valve mechanism for an internal combustion engine according to the present invention can be applied to both an intake valve and an exhaust valve in an internal combustion engine, and can be applied to both valves simultaneously. In addition, in the case of any one of the intake valve and the exhaust valve, when the valve is composed of a plurality of valves, it can be applied not only to all the plurality of valves but also to some of them. is there.

  As described above, in order to control the opening / closing characteristics of the valve that is opened and closed by the variable valve mechanism of the internal combustion engine according to the present invention, the relative position between the input unit and the rotating cam is changed. The control arm is fixed to the rotation control shaft, and the valve opening / closing control means rotates the control arm by rotating the rotation control shaft, thereby rotating the relative position between the input unit and the rotation cam. A means for changing the value can be considered.

  That is, the control arm and the rotation control shaft are fixed so that the rotation control shaft and the control arm are integrally rotated, and the control arm is driven by rotating the rotation control shaft. Rotation is driven around the rotation control axis. Further, when the input arm that is swingably connected to the control arm is swung, the input unit is moved, and the relative position between the input unit and the rotating cam is changed. In order to rotate the rotation control shaft, an electric motor such as a stepping motor or a servo motor can be preferably used.

  Further, as another means for changing the relative position between the input unit and the rotation cam, the rotation control shaft has a spiral spline along the axial direction, and the control arm has a spline of the rotation control shaft. The valve opening / closing control means changes the relative position between the input portion and the rotating cam by rotating the control arm by moving the rotation control shaft in the axial direction. A means to do this is conceivable.

  That is, the rotation control shaft and the control arm are engaged with each other via a spiral spline in the axial direction of the rotation control shaft. Accordingly, when the rotation control shaft moves in the axial direction, the control arm is driven to rotate about the rotation control shaft. On the other hand, when the movement of the rotation control shaft in the axial direction is prohibited, the rotation drive of the control arm around the rotation control shaft is also prohibited. With this configuration, the control arm is rotationally driven according to the movement of the rotation control shaft. Further, when the input arm that is swingably connected to the control arm is swung, the input unit is moved, and the relative position between the input unit and the rotating cam is changed. For the movement of the rotation control shaft, a hydraulic actuator, an electrostrictive element actuator, or the like can be suitably used.

  Here, in the variable valve mechanism for the internal combustion engine that controls the opening and closing of the valve by changing the relative position between the input unit and the rotating cam, the displacement amount of the rotation control shaft and the valve timing phase of the valve In this relation, a variable valve mechanism for an internal combustion engine characterized by the presence of a substantially linearity can be considered. In such a variable valve mechanism of an internal combustion engine, there is generally linearity in the relationship between the valve that is the final control target and the amount of displacement of the rotation control shaft that is directly controlled by the actuator. Valve timing control becomes easy. In other words, the linearity makes it possible to express the mutual relationship between the valve lift amount and the relative angle by a simple relational expression, thereby facilitating valve opening / closing control using the displacement amount of the rotation control shaft as a control parameter. Can be done.

  When the relative position between the input unit and the rotary cam is changed by rotationally driving the rotation control shaft, the displacement amount of the rotation control shaft refers to the rotation angle at which the rotation control shaft is rotated by the actuator. . Further, when the relative position between the input unit and the rotary cam is changed via a spiral spline, it refers to the amount of movement of the rotation control shaft in the axial direction by the actuator.

Furthermore, the following means can also be employed as means for solving the above-described problems. That is, it is a variable valve mechanism for an internal combustion engine that includes a rotary cam that is rotationally driven, and that can change the open / close characteristics of at least one of an intake valve and an exhaust valve that are opened and closed by the rotary cam by a variable valve transmission mechanism. The variable valve transmission mechanism includes an input arm that is in contact with the rotating cam and is swingably supported by the input support portion, and a transmission arm that is swingably coupled to the input arm. A swing arm that is swingably connected to the transmission arm and swingably supported by a swing support portion, and transmits a driving force transmitted from the rotating cam to an output portion that opens and closes the valve; The four-bar linkage mechanism is configured to control the posture of the four-bar linkage mechanism and change the relative position between the rotary cam and the input unit to open the valve. It characterized by having a valve opening and closing control means for controlling the characteristics.

  In the variable valve mechanism of the internal combustion engine configured as described above, the variable valve transmission mechanism includes an input arm, a transmission arm, and a swing arm, and the input arm can swing at the input support portion. The swing arm is a four-bar linkage mechanism that is swingably supported by the swing support portion, and the input portion provided on the input arm is driven by a rotating cam, and is connected via the variable valve transmission mechanism. Thus, the output unit is driven, and the valve is opened and closed. That is, when the input unit is driven by the rotating cam in a state where the input support unit is fixed, the output unit swings through the transmission arm and the swing arm, and valve opening / closing control is performed. Further, in this variable valve mechanism of the internal combustion engine, the relative position between the input portion and the rotary cam can be changed by the valve opening / closing control means to control the opening / closing characteristics of the valve. That is, by changing the relative position between the input unit and the rotary cam, the phase of the input unit relative to the rotary cam is changed to adjust the valve timing of the valve that is opened and closed by the variable valve mechanism. It becomes possible to do.

  On the other hand, by changing the relative position between the input unit and the rotating cam, the posture of the link mechanism including the input arm, the transmission arm, and the swing arm is changed. Along with this, the displacement amount of the output part that opens and closes the valve also fluctuates in conjunction with it, and the lift amount of the valve also fluctuates. As described above, by controlling the attitude of the four-bar linkage mechanism in the variable valve mechanism by changing the relative position between the input unit and the rotary cam, the valve timing phase and the valve lift amount, which are the valve opening / closing characteristics, can be simultaneously adjusted. It becomes possible to control. In addition, by controlling the attitude of the four-bar linkage mechanism with one drive device (actuator), the valve timing phase and the valve lift amount, which are the valve opening / closing characteristics, are controlled with one actuator.

  Since the valve timing phase and the control amount of the valve lift amount are affected by the dimensions of the input arm, transmission arm and swing arm constituting the four-bar linkage mechanism, the valve timing and valve lift required for the internal combustion engine are required. It is desirable to configure the link mechanism with dimensions corresponding to the amount. As described above, in order to control the opening / closing characteristics of the valve that is opened and closed by the variable valve mechanism of the internal combustion engine according to the present invention, the relative position between the input portion and the rotating cam is changed. A means for converting the rotational motion of an actuator such as an electric motor into a linear motion by using a pinion mechanism or the like and moving the input arm can be considered.

  The variable valve mechanism for an internal combustion engine according to the present invention can be applied to both an intake valve and an exhaust valve in an internal combustion engine, and can be applied to both valves simultaneously. In addition, in the case of any one of the intake valve and the exhaust valve, when the valve is composed of a plurality of valves, it can be applied not only to all the plurality of valves but also to some of them. is there.

Here, when the position where the valve opening / closing control means acts on the input arm, that is, the position where the actuator acts on the input arm is used as a control point, the relative position between the input portion and the rotating cam is changed to change the valve. In the above variable valve mechanism for an internal combustion engine that performs opening / closing control of the internal combustion engine, there is provided a variable valve mechanism for an internal combustion engine characterized in that a linearity exists in a relationship between a displacement amount of a control point and a valve timing phase of the valve. Conceivable. In such a variable valve mechanism of an internal combustion engine, there is generally linearity in the relationship between the valve that is the final control target and the displacement of the control point in the input arm that is directly controlled by the actuator, Valve timing control of the valve becomes easy. In other words, the linearity allows the mutual relationship between the valve lift amount and the relative angle to be expressed by a simple relational expression, so that the valve opening / closing control is easily performed using the displacement amount of the control point as a control parameter. be able to.

  In order to solve the above-described problems in an internal combustion engine in which either the intake valve or the exhaust valve is configured by a plurality of valves, the following means can be employed. That is, a variable valve mechanism for an internal combustion engine according to the present invention includes a first rotary cam and a second rotary cam that are rotationally driven, and at least one of an intake side or an exhaust side in the same cylinder of the internal combustion engine is at least In an internal combustion engine comprising two valves, a first valve opened and closed by the first rotating cam and a second valve opened and closed by the second rotating cam, at least opening and closing characteristics of the first valve and the second valve Are variable valve mechanisms for an internal combustion engine that are variable by a first variable valve transmission mechanism and a second variable valve transmission mechanism, respectively, wherein the first variable valve transmission mechanism abuts on the first rotary cam. A first input arm having a first input portion; a first transmission arm that is swingably connected to the first input arm; and a rotation control shaft that is swingably connected to the first transmission arm. A first swing arm that transmits a driving force transmitted from the first rotary cam to a first output unit that opens and closes the first valve, the first input arm, and the first input arm. A second control valve transmission mechanism having a second input portion that contacts the second rotating cam. An input arm, a second transmission arm that is swingably connected to the second input arm, a swingable connection to the second transmission arm and a swing control shaft. A second swing arm that transmits a driving force transmitted from the second rotary cam to a second output portion that opens and closes the second valve; and a second swing arm that connects the second input arm and the second swing arm. Four-bar link consisting of two control arms And opening and closing characteristics of the first valve by making the attitude of the four-bar linkage mechanism in the first variable valve transmission mechanism different from the attitude of the four-bar linkage mechanism in the second variable valve transmission mechanism. It has valve characteristic control means for making the opening / closing characteristic of the second valve different.

  In the variable valve mechanism of the internal combustion engine configured as described above, the first rotary cam and first variable valve transmission mechanism for controlling the opening and closing of the first valve and the second valve, the second rotary cam and the second valve, respectively. A variable valve transmission mechanism, and valve characteristic control means for making the opening / closing characteristics of the first valve different from the opening / closing characteristics of the second valve. Here, the first variable valve transmission mechanism and the second variable valve transmission mechanism are four-bar linkage mechanisms each composed of an input arm, a transmission arm, a swing arm, and a control arm, and are provided in the input arm. The input unit is driven by the rotating cam, and the output unit is driven through each variable valve transmission mechanism, thereby opening and closing the valve.

Further, in this variable valve mechanism of the internal combustion engine, the posture of the four-bar link mechanism in the first variable valve transmission mechanism and the posture of the four-bar link mechanism in the second variable valve transmission mechanism are controlled by the valve characteristic control means. By making them different, it is possible to provide a difference in the valve opening / closing characteristics of the first valve and the second valve. By changing the position of each input section and each rotary cam by changing the attitude of the four-bar linkage mechanism in each variable valve transmission mechanism, the valve timing phase, which is the valve opening / closing characteristics, and the valve lift amount are changed. All that can be done is as described above. Here, by providing a difference in valve opening / closing characteristics between the first valve and the second valve, intake / exhaust performed through the valve can be controlled. In particular, in the first valve and the second valve of the intake valve, by changing the lift amount of the valve, which is one of the valve characteristics, the flow rate of air flowing into the combustion chamber through the first valve and the second valve are changed. Therefore, the flow rate of air flowing into the combustion chamber is different, and as a result, a swirling flow can be generated in the combustion chamber. By generating a swirl flow in the combustion chamber,
The diffusion of fuel in the combustion chamber advances, and the stability of combustion improves.

  Here, since the strength of the swirl flow is caused by the flow rate of air flowing into the combustion chamber and the lift amount difference between the first valve and the second valve, the first swirl flow is obtained at a predetermined air flow rate. It is desirable to determine the dimensions of the links constituting the variable valve transmission mechanism and the second variable valve transmission mechanism.

  The variable valve mechanism for an internal combustion engine according to the present invention can be applied to either an intake valve or an exhaust valve, or to both an intake and exhaust valve. Furthermore, when the intake valve or exhaust valve to be applied is composed of a plurality of valves, the present invention can be applied to any two of the constituent valves.

  Furthermore, in order to solve the above-described problem in an internal combustion engine in which either the intake valve or the exhaust valve is configured by a plurality of valves, another means described below can be adopted. That is, a variable valve mechanism for an internal combustion engine according to the present invention includes a first rotary cam and a second rotary cam that are rotationally driven, and at least one of an intake side or an exhaust side in the same cylinder of the internal combustion engine is at least In an internal combustion engine comprising two valves, a first valve opened and closed by the first rotating cam and a second valve opened and closed by the second rotating cam, at least opening and closing characteristics of the first valve and the second valve Are variable valve mechanisms for an internal combustion engine that are variable by a first variable valve transmission mechanism and a second variable valve transmission mechanism, respectively, wherein the first variable valve transmission mechanism abuts on the first rotary cam. A first input arm having a first input portion and supported swingably on the first input support portion; a first transmission arm swingably connected to the first input arm; and the first transmission arm. The driving force transmitted from the first rotating cam is transmitted to the first output unit that opens and closes the first valve. And a second variable valve transmission mechanism having a second input portion that comes into contact with the second rotary cam and a second input support portion. A second input arm that is swingably supported, a second transmission arm that is swingably connected to the second input arm, and a second swing that is swingably connected to the second transmission arm. And a second swing arm that is swingably supported by the support portion and transmits a driving force transmitted from the second rotary cam to a second output portion that opens and closes the second valve. The first variable valve transmission device comprising a link mechanism A valve that makes the opening and closing characteristics of the first valve different from the opening and closing characteristics of the second valve by making the attitude of the four-bar linkage mechanism in FIG. 4 different from the attitude of the four-bar linkage mechanism in the second variable valve transmission mechanism It has characteristic control means.

  In the variable valve mechanism of the internal combustion engine configured as described above, the first rotary cam and first variable valve transmission mechanism for controlling the opening and closing of the first valve and the second valve, the second rotary cam and the second valve, respectively. A variable valve transmission mechanism, and valve characteristic control means for making the opening / closing characteristics of the first valve different from the opening / closing characteristics of the second valve. Here, the first variable valve transmission mechanism and the second variable valve transmission mechanism are link mechanisms configured by respective input arms, transmission arms, and swing arms, and an input unit provided on the input arm includes: By being driven by the rotating cam, the output unit is driven via each variable valve transmission mechanism, thereby opening and closing the valve.

Further, in this variable valve mechanism of the internal combustion engine, the posture of the four-bar link mechanism in the first variable valve transmission mechanism and the posture of the four-bar link mechanism in the second variable valve transmission mechanism are controlled by the valve characteristic control means. By making them different, it is possible to provide a difference in the valve opening / closing characteristics of the first valve and the second valve. By changing the position of each input section and each rotary cam by changing the attitude of the four-bar linkage mechanism in each variable valve transmission mechanism, the valve timing phase, which is the valve opening / closing characteristics, and the valve lift amount are changed. All that can be done is as described above. Here, by providing a difference in valve opening / closing characteristics between the first valve and the second valve, intake / exhaust performed through the valve can be controlled. In particular, in the first valve and the second valve of the intake valve, by changing the lift amount of the valve, which is one of the valve characteristics, the flow rate of air flowing into the combustion chamber through the first valve and the second valve are changed. Therefore, the flow rate of air flowing into the combustion chamber is different, and as a result, a swirling flow can be generated in the combustion chamber. When the swirl flow is generated in the combustion chamber, the diffusion of fuel in the combustion chamber proceeds and the stability of combustion is improved.

  Here, since the strength of the swirl flow is caused by the flow rate of air flowing into the combustion chamber and the lift amount difference between the first valve and the second valve, the first swirl flow is obtained at a predetermined air flow rate. It is desirable to determine the dimensions of the links constituting the variable valve transmission mechanism and the second variable valve transmission mechanism.

  The variable valve mechanism for an internal combustion engine according to the present invention can be applied to either an intake valve or an exhaust valve, or to both an intake and exhaust valve. Furthermore, when the intake valve or exhaust valve to be applied is composed of a plurality of valves, the present invention can be applied to any two of the constituent valves.

  Here, the following means can be considered as valve characteristic control means in the case where the above-mentioned four-bar linkage mechanism is constituted by four arms of an input arm, a transmission arm, a swing arm, and a control arm. That is, it further includes a coupling mechanism that couples the first variable valve transmission mechanism and the second variable valve transmission mechanism, and the first control arm is driven to rotate about the rotation control shaft as the rotation center. The second input arm is swingably connected to the first input arm, and the second control arm is swingably connected to the rotation control shaft and is swingably connected to the second input arm. When the opening / closing characteristics of the first valve and the opening / closing characteristics of the second valve are the same, the valve characteristic control means uses the coupling mechanism to connect the first variable valve transmission mechanism and the second variable valve transmission mechanism. By connecting, the attitude of the four-bar linkage mechanism in the first variable valve transmission mechanism and the attitude of the four-bar linkage mechanism in the second variable valve transmission mechanism are the same, and the opening and closing characteristics of the first valve When making the opening / closing characteristic of the second valve different, the connection between the first variable valve transmission mechanism and the second variable valve transmission mechanism by the connection mechanism is released and the first variable valve transmission By changing the attitude of the four-bar linkage mechanism in the mechanism, the attitude of the four-bar linkage mechanism in the first variable valve transmission mechanism and the attitude of the four-bar linkage mechanism in the second variable valve transmission mechanism are made different. It is characterized by.

  In the variable valve mechanism of the internal combustion engine having the valve characteristic control means configured as described above, the first control arm is driven to rotate about the rotation control shaft while the second control arm is centered on the rotation control shaft. Swing as. Therefore, the first control arm is directly driven to rotate about the rotation control axis by the actuator that controls the attitude of the four-bar linkage mechanism in the first variable valve transmission mechanism. Here, by connecting the first variable valve transmission mechanism and the second variable valve transmission mechanism by the coupling mechanism, the attitude of the four-bar linkage mechanism in the first variable valve transmission mechanism and the second variable valve transmission mechanism The four-bar linkage mechanism in FIG. 4 can be made to have the same posture, and thus the opening and closing characteristics of the first valve and the second valve can be made the same. In addition, the four-bar linkage mechanism in the first variable transmission mechanism and the four-bar linkage mechanism in the second variable valve transmission mechanism can be simultaneously changed via the coupling mechanism, so that the first valve and the second valve can be changed. The opening and closing characteristics can be changed at the same time.

On the other hand, by releasing the connection by the connection mechanism, the first variable valve transmission mechanism and the second variable valve transmission mechanism become a four-bar linkage mechanism independent of each other. Therefore, in the second variable valve transmission mechanism, the relative position between the second input portion and the second rotating cam at the time when the connection is released is maintained, and the opening / closing characteristics of the second valve are based on the relative position. . In the first variable valve transmission mechanism, the relative position between the first input portion and the first rotating cam can be changed by the actuator that controls the attitude of the four-bar linkage mechanism to change the opening / closing characteristics of the first valve. It becomes possible. That is, the open / close characteristics of the first valve and the second valve can be made different. Therefore, by providing the coupling mechanism, the opening / closing characteristics of the first valve and the second valve can be made the same characteristic or different characteristics by one actuator in the valve opening / closing control means. Here, as a connection mechanism, it is possible to mechanically connect a certain part in the first variable valve transmission mechanism and a certain part in the second variable valve transmission mechanism corresponding to the part. As a mechanical connection means, insertion of a pin or the like can be considered.

  Here, the following means can be considered as the valve characteristic control means when the above-mentioned four-bar linkage mechanism is constituted by three arms of the input arm, the transmission arm, and the swing arm. That is, it further includes a coupling mechanism that couples the first variable valve transmission mechanism and the second variable valve transmission mechanism, and the valve characteristic control means includes the first valve opening and closing characteristics and the second valve opening and closing characteristics. , The first variable valve transmission mechanism and the second variable valve transmission mechanism are connected by the connection mechanism, so that the four-link mechanism of the first variable valve transmission mechanism When the posture and the posture of the four-bar linkage mechanism in the second variable valve transmission mechanism are the same, and the opening / closing characteristics of the first valve and the opening / closing characteristics of the second valve are different, By releasing the connection between the one variable valve transmission mechanism and the second variable valve transmission mechanism and changing the attitude of the four-bar linkage mechanism in the first variable valve transmission mechanism via the rotation control shaft , Said first possible Characterized in that made different and the orientation of the four-bar linkage and the attitude of the four-bar linkage mechanism in the valve operating transmission mechanism in the second variable valve transmission mechanism.

  In the variable valve mechanism of the internal combustion engine having the valve characteristic control means configured as described above, the first variable valve transmission mechanism and the second variable valve transmission mechanism are connected by the connection mechanism, so that the first possible The attitude of the four-bar linkage mechanism in the variable valve transmission mechanism and the attitude of the four-bar linkage mechanism in the second variable valve transmission mechanism can be made the same, so that the opening and closing characteristics of the first valve and the second valve are the same. Can be. In addition, the four-bar linkage mechanism in the first variable transmission mechanism and the four-bar linkage mechanism in the second variable valve transmission mechanism can be simultaneously changed via the coupling mechanism, so that the first valve and the second valve can be changed. The opening and closing characteristics can be changed at the same time.

  On the other hand, by releasing the connection by the connection mechanism, the first variable valve transmission mechanism and the second variable valve transmission mechanism become a four-bar linkage mechanism independent of each other. Therefore, in the second variable valve transmission mechanism, the relative position between the second input portion and the second rotating cam at the time when the connection is released is maintained, and the opening / closing characteristics of the second valve are based on the relative position. . In the first variable valve transmission mechanism, the relative position between the first input portion and the first rotating cam can be changed by the actuator that controls the attitude of the four-bar linkage mechanism to change the opening / closing characteristics of the first valve. It becomes possible. That is, the open / close characteristics of the first valve and the second valve can be made different. Therefore, by providing the coupling mechanism, the opening / closing characteristics of the first valve and the second valve can be made the same characteristic or different characteristics by one actuator in the valve opening / closing control means. Here, as a connection mechanism, it is possible to mechanically connect a certain part in the first variable valve transmission mechanism and a certain part in the second variable valve transmission mechanism corresponding to the part. As a mechanical connection means, insertion of a pin or the like can be considered.

Further, in the valve characteristic control means, when the opening / closing characteristics of the first valve and the opening / closing characteristics of the second valve are made different, the four-bar linkage in the second variable valve transmission mechanism is set so that the working angle of the second valve becomes an extreme value. The posture of the mechanism is maintained. In the variable valve mechanism of the internal combustion engine having the valve characteristic control means configured as described above, the connection between the first variable valve transmission mechanism and the second variable valve transmission mechanism is released by releasing the connection mechanism. At this time, the attitude of the four-bar linkage mechanism in the second variable valve transmission mechanism is maintained so that the operating angle of the second valve becomes an extreme value. Here, the extreme value means that the lift amount of the second valve is a maximum value or a minimum value. Therefore, in the variable valve mechanism of the internal combustion engine according to the present invention, when the opening / closing characteristics of the first valve and the opening / closing characteristics of the second valve are made different, the lift amount of the second valve is always an extreme value. By controlling the first valve by the opening / closing control means, it becomes easier to set the difference in the lift amount of the two valves to be larger, thereby increasing the strength of the swirling flow generated in the combustion chamber.

  Further, the four-bar linkage mechanism in the variable valve transmission mechanism described above can adjust the valve timing phase, which is the valve opening / closing characteristic. That is, the phase of the valve shifts to the advance side or the retard side as the lift amount of the valve that is opened and closed through the variable valve mechanism including the four-bar linkage mechanism decreases. . In particular, when opening and closing the intake valve, the valve timing phase shifts to the advance side as the valve lift amount decreases, thereby reducing the valve lift amount while maintaining the valve opening timing at substantially the same time. It becomes possible to do. In addition, when opening and closing the valve exhaust valve, the valve phase shifts to the retard side as the valve lift amount decreases, so that the valve lift amount can be reduced while maintaining the valve closing timing at substantially the same time. It can be made smaller.

  Furthermore, the four-bar linkage mechanism in the variable valve transmission mechanism described above changes the attitude of the four-bar linkage based on the load of the internal combustion engine, thereby increasing the operating angle of the intake valve and the exhaust valve. It is possible to control the overlap amount, which is the overlapping working angle with the working angle by opening the valve. In other words, for the purpose of improving combustion stability and volumetric efficiency, etc., depending on the load conditions in the internal combustion engine such as an idle region, a light load region, a medium load region, a high load low medium speed rotation region, a high load high speed rotation region, etc. The variable valve mechanism for an internal combustion engine according to the invention is useful.

  In addition, the output unit, the first output unit, and the second output unit described above have a rocker arm that opens and closes the valve by abutting the swing arm and swinging according to the swing arm. It is characterized by. Thus, in the variable valve mechanism of the internal combustion engine configured as described above, the swing of the swing arm can be transmitted to the valve via the rocker arm. Therefore, by adjusting the rocking center of the rocker arm and the distance from the rocking center to the valve, it is possible to adjust the deceleration of the rocking of the rocking arm.

  The variable valve mechanism for an internal combustion engine according to the present invention is an internal combustion engine having a rotary cam that is rotationally driven, wherein the open / close characteristic of at least one of the intake valve and the exhaust valve is variable by the variable valve transmission mechanism. A variable valve mechanism for an engine, wherein the variable valve transmission mechanism is composed of a four-bar linkage mechanism having an input arm having an input portion that contacts the rotating cam, and further controls the attitude of the four-bar link mechanism. The open / close characteristics of the valve are controlled by changing the relative position of the rotary cam and the input unit.

  According to the present invention, the posture of the four-bar linkage mechanism is controlled by a single actuator. Accordingly, it is possible to adjust the opening / closing characteristics of the intake valve or the exhaust valve by changing the relative position between the rotary cam and the input unit by a single actuator. As a result, the variable valve mechanism of the internal combustion engine can be simplified.

<First embodiment>
Embodiments of a variable valve mechanism for an internal combustion engine according to the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing a schematic configuration of an internal combustion engine 1 to which the above-described invention is applied and its control system. FIG. 2 is a diagram showing a schematic configuration in the vicinity of the cylinder head of the cylinder 2 in the internal combustion engine 1.

  The internal combustion engine 1 includes a fuel injection valve 3 that injects fuel into the intake port of each cylinder 2. Each fuel injection valve 3 is connected to a pressure accumulation chamber 4 that accumulates fuel at a predetermined pressure. The pressure accumulating chamber 4 communicates with the fuel pump 6 through the fuel supply pipe 5. The fuel pump 6 is a pump that operates using the rotational torque of the output shaft (crankshaft) of the internal combustion engine 1 as a drive source. A pump pulley 6 a attached to the input shaft of the fuel pump 6 is connected to the output shaft ( And a crank pulley 1a attached to the crankshaft) via a belt 7. In the fuel injection system configured as described above, when the rotational torque of the crankshaft is transmitted to the input shaft of the fuel pump 6, the fuel pump 6 transmits the rotational torque transmitted from the crankshaft to the input shaft of the fuel pump 6. The fuel is pressurized and discharged. The fuel is discharged at a corresponding pressure. The fuel discharged from the fuel pump 6 is supplied to the pressure accumulating chamber 4 through the fuel supply pipe 5, accumulated at a predetermined pressure in the pressure accumulating chamber 4, and distributed to the fuel injection valves 3 of each cylinder 2. When a drive current is applied to the fuel injection valve 3, the fuel injection valve 3 is opened, and as a result, fuel is injected from the fuel injection valve 3.

  A first intake valve 201a, a second intake valve 201b, a first exhaust valve 203a, and a second exhaust valve 203b are disposed in the combustion chamber 301 in each cylinder 2. Of these, the first intake valve 201a opens and closes the first intake port 202a, the second intake valve 201b opens and closes the second intake port 202b, the first exhaust valve 203a opens and closes the first exhaust port 204a, and the second The exhaust valve 203b is disposed so as to open and close the second exhaust port 204b.

  Here, an intake branch pipe 8 is connected to the internal combustion engine 1, and each branch pipe of the intake branch pipe 8 communicates with the combustion chamber 301 of each cylinder 2 via the intake ports 202a and 202b. The intake branch pipe 8 is connected to an intake pipe 9. An air flow meter 10 that outputs an electrical signal corresponding to the mass of the intake air flowing through the intake pipe 9 is attached to the intake pipe 9. An intake throttle valve 11 for adjusting the flow rate of the intake air flowing through the intake pipe 9 is provided at a portion of the intake pipe 9 located immediately upstream of the intake branch pipe 8. The intake throttle valve 11 is provided with an intake throttle actuator 12 that is configured by a step motor or the like and that drives the intake throttle valve 11 to open and close.

  On the other hand, an exhaust branch pipe 13 is connected to the internal combustion engine 1, and each branch pipe of the exhaust branch pipe 13 communicates with the combustion chamber 301 of each cylinder 2 via exhaust ports 204a and 204b. The exhaust branch pipe 13 is connected to an exhaust pipe 14, and the exhaust pipe 14 is connected downstream to a muffler (not shown). Further, an exhaust purification catalyst 17 for purifying harmful components contained in the exhaust discharged from the internal combustion engine 1 is provided in the middle of the exhaust pipe 14.

  The exhaust pipe 14 located downstream of the exhaust purification catalyst 17 is provided with an exhaust throttle valve 15 for adjusting the flow rate of the exhaust gas flowing through the exhaust pipe 14. The exhaust throttle valve 15 is provided with an exhaust throttle actuator 16 that is configured by a step motor or the like and that drives the exhaust throttle valve 15 to open and close.

Intake and exhaust in the combustion chamber 301 of the internal combustion engine 1 configured as described above will be described with reference to FIG. FIG. 3 shows a longitudinal sectional view of a cross section including the intake port 202a and the exhaust port 204a in the cylinder 2 of the internal combustion engine 1. Here, according to the signal from the accelerator pedal opening sensor 20 and the engine speed Ne of the internal combustion engine 1, the intake throttle valve 11 is opened by the operation of the intake throttle actuator 12, and the fuel injection valve 3 is energized. As a result, a required amount of air and fuel flow into the intake port 202a. Further, air and fuel in an amount corresponding to the lift amount of the intake valve 201 a flows into the combustion chamber 301. At this time, the opening and closing of the intake valve 201a is constituted by the swing arm 401, the control arm 402, the transmission arm 403, and the input arm 404 by the rotation of the intake cam 305 provided on the intake cam shaft 306 accompanying the rotation of the internal combustion engine 1. This is done via a four-section link.

  Note that the ECU 23, which is an electronic control unit of the internal combustion engine 1, drives the variable valve transmission mechanism actuator 21 via the oil control valve (OCV) 22 to drive the rotation control shaft 408 to rotate, thereby transmitting the variable valve transmission. Change the attitude of the mechanism's four-bar link. Detailed operation of the variable valve transmission mechanism will be described later.

  Further, the first exhaust valve 203 a that opens and closes the first exhaust port 204 a of the cylinder 2 is connected via the rocker arm 310 by the rotation of the exhaust cam 308 provided on the exhaust camshaft 309 accompanying the rotation of the internal combustion engine 1. It is opened and closed with a certain lift amount.

  Returning to FIG. 1 again, the control system of the internal combustion engine 1 will be described. The ECU 23 comprises a digital computer, and is connected to each other via a bidirectional bus 27, a RAM (Random Access Memory) 30, a ROM (Read Only Memory) 29, a CPU (Microprocessor) 28, an input port 25 and an output port. 26. Further, an A / D converter 24 that converts an analog signal input from the outside of the ECU 23 into a digital input after being converted into a digital signal is connected to the input port 25.

  An accelerator opening sensor 20 that outputs a voltage proportional to the depression amount of the accelerator pedal to the ECU 23 is input to the input port 25 via the AD converter 24. The crank position sensor 19 generates an output pulse every time the crankshaft rotates 30 °, for example, and this output pulse is input to the input port 25. The CPU 23 calculates the engine speed Ne of the internal combustion engine 1 based on the output pulse of the crank position sensor 19 and the like.

  Further, the shaft position sensor 18 for detecting the axial displacement of the rotation control shaft 408 moved by the variable valve transmission mechanism actuator 21 inputs an output voltage corresponding to the axial displacement to the input port 25 via the AD converter 24. ing. In addition to this, various signals are input to the input port 25, but they are not shown in the present embodiment because they are not important in the description.

  The output port 26 is electrically connected to the fuel injection valve 3 of each cylinder 2, and the ECU 23 performs valve opening control of each fuel injection valve 3 in accordance with the operating state of the internal combustion engine 1 to control fuel injection timing and fuel injection. Quantity control is being executed. Further, the output port 26 is connected to the oil control valve 22, and the ECU 23 controls the variable valve transmission mechanism actuator 21 via the oil control valve 22 in accordance with the operation state of the internal combustion engine 1 such as a required intake air amount. ing. As a result, the lift amount and valve timing of the intake valve 201a are controlled by the ECU 23, and intake air amount control and other controls (for example, volumetric efficiency improvement and internal EGR amount control, etc.) are executed.

  Here, the variable valve transmission mechanism that transmits the driving force of the intake cam 305 to the intake valve 201a and opens and closes the drive force will be described. 4 and 5 are detailed views of a main part of a four-bar linkage mechanism that constitutes a variable valve transmission mechanism that controls opening and closing of the intake valve 201a, and FIG. 6 is a detailed view of a control arm 402 that constitutes the four-bar link mechanism. FIG. 7 is a detailed view of the rotation control shaft 408 for rotationally driving the control arm, and FIG. 8 is a detailed view of the variable valve transmission mechanism actuator 21 for moving the rotation control shaft in the axial direction.

Here, the configuration of the control arm 402 and the rotation control shaft 408 will be described with reference to FIGS. 6 and 7. The control arm 402 is an arm that is rotationally driven by driving the rotation control shaft 408. As shown in FIG. 6, the control arm 402 includes an arm portion 402a and a base portion 402b, and a distal end portion of the arm portion 402a is connected to the input arm 404 to form a joint J1. Is provided. Further, the base portion 402b is hollow, and a spiral spline portion 402d is provided on the inner wall surface in the central axis direction of the base portion 402b.

  On the other hand, the rotation control shaft 408 shown in FIG. 7 includes a shaft portion 408b and a spiral spline portion 408a provided in the axial direction. The spline portion 402d of the control arm 402 and the spline portion 408a of the rotation control shaft 408 are configured to mesh with each other. Here, when the rotation control shaft 408 moves in the axial direction, the control arm 402 follows the spiral spline and rotates about the rotation control shaft 408. On the other hand, by prohibiting movement of the rotation control shaft 408 in the axial direction, rotation of the control arm 402 around the rotation control shaft 408 is also prohibited.

  Next, the variable valve transmission mechanism actuator 21 that moves the rotation control shaft 408 described above will be described with reference to FIG. The variable valve transmission mechanism actuator 21 includes a cylindrical cylinder tube 21a, a piston 21b provided in the cylinder tube 21a, and a pair of end covers 21c provided so as to close both end openings of the cylinder tube 21a. 21d and a coil spring 21e in a compressed state disposed between an end cover 21c located on the opposite side of the rotation control shaft 8 and the piston 21b. Further, the inner end cover 21 d is fixed to the outer wall 1 b of the internal combustion engine 1.

  One end of a rotation control shaft 408 passing through the inner end cover 21d and the outer wall 1b of the internal combustion engine 1 is connected to the piston 21b. Therefore, the rotation control shaft 408 is interlocked with the piston 21b. Here, the inside of the cylinder tube 21a is partitioned into a first pressure chamber 21f and a second pressure chamber 21g by a piston 21b. A first supply / discharge passage 21h formed in one end cover 21d is connected to the first pressure chamber 21f, and a second supply / discharge passage 21i formed in the other end cover 21c is connected to the second pressure chamber 21g. Is connected.

  When hydraulic fluid is selectively supplied to the first pressure chamber 21f and the second pressure chamber 21g via the first supply / discharge passage 21h or the second supply / discharge passage 21i, the piston 21b moves in the axial direction of the rotation control shaft 408. Move in the direction of arrow S. As the piston 21b moves, the rotation control shaft 408 also moves in the axial direction.

  The first supply / discharge passage 21 h and the second supply / discharge passage 21 i are connected to the oil control valve 22. In accordance with a command from the ECU 23, the oil control valve 22 supplies hydraulic oil to the first pressure chamber 21f or the second pressure chamber 21g in the variable valve transmission mechanism actuator 21 via the first supply / discharge passage 21h or the second supply / discharge passage 21i. It is a device which supplies.

  The control arm 402, the rotation control shaft 408, and the variable valve transmission mechanism actuator 21 configured as described above are configured such that the oil control valve 22 supplies hydraulic oil to the variable valve transmission mechanism actuator 21 according to a command from the ECU 23. The rotation control shaft 408 moves in the axial direction. Accordingly, the control arm 402 rotates about the rotation control shaft 408, and the input arm 404 that is swingably connected to the control arm 402 moves, whereby the input roller 405 provided on the input arm 404 is moved. And the relative position of the intake cam 305 in contact with the input roller 405 are changed. On the other hand, when the supply of hydraulic oil to the oil control valve 22 is prohibited, the rotation control shaft 408 is prohibited from moving in the axial direction, and the rotation of the control arm 402 around the rotation control shaft 408 is also prohibited. .

Another embodiment of the configuration of the control arm 402, the rotation control shaft 408, and the variable valve transmission mechanism actuator 21 is shown in FIG. In the embodiment shown in FIG. 9, the variable valve transmission mechanism 21 is an electric motor such as a stepping motor. Here, the variable valve transmission mechanism actuator 21 is installed on the outer wall 1 b of the internal combustion engine 1 via the adapter 422, and the rotating shaft 420 of the variable valve transmission mechanism actuator 21 rotates via the coupling 421. The control shaft 408 is connected. The rotation control shaft 408 passes through the outer wall 1 b of the internal combustion engine 1 and is fixed to the control arm 402. Therefore, the control arm 402 is directly rotated by the rotation output of the variable valve transmission mechanism actuator 21.

  The control arm 402, the rotation control shaft 408, and the variable valve transmission mechanism actuator 21 configured as described above rotate the rotation control shaft 408 in accordance with a command from the ECU 23. As a result, the control arm 402 rotates integrally with the rotation control shaft, and the input arm 404 that is swingably connected to the control arm 402 moves, whereby the input roller 405 provided on the input arm 404 is moved. And the relative position of the intake cam 305 in contact with the input roller 405 are changed. On the other hand, when the variable valve transmission mechanism actuator 21 is stopped, the rotation of the rotation control shaft 408 is prohibited. In the embodiment shown in FIG. 9, the rotary shaft 420 and the rotation control shaft 408 are directly connected via a coupling, but may be connected via a speed reducer therebetween. By doing so, it becomes possible to reduce the capacity | capacitance of the variable valve transmission mechanism actuator 21 which is an electric motor.

  Here, based on FIG.4 and FIG.5, operation | movement of the four-bar link which comprises a variable valve transmission mechanism is demonstrated. FIG. 4 is a diagram illustrating the operation of the four-bar link when the control arm 402 maintains a horizontal posture in the drawing. FIG. 5 is a diagram showing the operation of the four-bar link when the control arm 402 is inclined to the lower right by φ1 from the position of FIG. 4A and 4B, FIG. 4A is an operation diagram of the four-bar link when the minimum radius portion of the intake cam 305 is in contact with the input roller 405, and FIG. It is an operation | movement figure of a four-bar link when the largest radius site | part of 305 is contact | abutting to the input roller 405. FIG.

  First, the operation of the four-bar link in FIG. 4 will be described. An input roller 405 serving as an input portion is in contact with an intake cam 305 provided on an intake shaft 306 driven by a crankshaft of the internal combustion engine 1 at an abutment point P1 (P1 is a point on the intake cam). The input roller 405 is provided on the input arm 404. Although the input arm 404 is not shown in FIG. 4, the input roller 405 is always attached to the intake cam 305 by the spring 307 shown in FIG. It is biased to abut. Accordingly, when the intake cam 305 is driven to rotate, the input roller 405 is driven following the outline of the intake cam 305, and the intake valve 201a is opened and closed through the four-bar link or the like.

  When the intake valve 201a is finally opened and closed by rotationally driving the intake cam 305, the posture of the control arm 402 is in principle maintained. In maintaining the posture of the control arm 402, when the variable valve transmission mechanism actuator 21 is the device shown in FIG. 8, the supply of hydraulic oil from the oil control valve 22 described above may be stopped. Further, when the variable valve transmission mechanism actuator 21 is an electric motor, the motor is stopped by continuously sending an excitation command to the electric motor, or the rotation control shaft is driven by a brake mechanism (not shown) provided inside or outside the electric motor. What is necessary is just to prohibit rotation of 408.

In the state where the control arm 402 holds the posture, the intake cam 305 is driven to rotate. When the maximum radius portion of the intake cam is in contact with the input roller 405 (state of FIG. 4B), when the input roller 405 is pushed in and the minimum radius portion of the intake cam is in contact (see FIG. 4 (A)), the input roller 405 has the least amount of pushing. The intake cam 305 and the input roller 405 are always kept in contact with each other by the urging force of the spring 307. When the input roller 405 is pressed against the intake cam 305, the driving force from the intake cam 305 is transmitted to the input arm 404 on which the input roller 405 is installed. Here, the input arm 404 is swingably connected to the control arm 402 at J1 which is a joint of the four-bar linkage mechanism. Accordingly, the input arm 404 swings about the joint J1.

  Further, the input arm 404 is swingably connected to the transmission arm 403 at J2 which is a joint of the four-bar linkage mechanism. Accordingly, as the input arm 404 swings about the joint J1, the transmission arm 403 swings about the joint J2.

  Further, the transmission arm 403 is one end of the swing arm 401 and is swingably connected to the swing arm 401 at a joint J3 of the four-bar linkage mechanism. Accordingly, when the transmission arm 403 swings about the joint J2, the driving force from the intake cam is transmitted to the swing arm 401 via the joint J3. The swing arm 401 is swingably connected to the rotation control shaft 408, and the rotation control shaft 408 is prohibited from moving. Therefore, the swing arm 401 swings around the rotation control shaft 408 by the driving force.

  The swing arm 401 has a nose 401 b that is a protruding portion, and the nose 401 b swings as the swing arm 401 swings around the rotation control shaft 408. Further, the output unit for transmitting the driving force from the intake cam 305 transmitted to the nose 401 b to the intake valve 201 a is constituted by a rocker arm roller 406, a rocker arm 407 and an adjuster 304.

  Here, the nose 401 b comes into contact with the rocker arm roller 406 depending on the posture of the swing arm 401. That is, when the inclination of the nose 401b is small, the rocker arm roller 406 is in contact with the outer circumference 401c of the swing arm 401. When the inclination of the nose 401b is increased, the rocker arm roller 406 is in contact with the nose 401b. Will be in touch.

  The rocker arm roller 406 is provided on the rocker arm 407, and the rocker arm 407 is supported by the adjuster 304 at the base end, and the stem end 303 at the distal end located on the side opposite to the base end. Is connected to the intake valve 201a. Therefore, as long as the inclination of the nose 401b is small and the rocker arm roller 406 is in contact with the outer circumference 401c, the rocker arm roller 406 cannot be pushed down. However, the inclination of the nose 401b increases so that the nose 401b When coming into contact with the roller 406, the rocker arm roller 406 is pushed down, the rocker arm 407 swings around the base end, and the stem end 303 is lowered. When the stem end 303 is lowered, the intake valve 201a is pushed down, so that the intake valve 201a is opened. The amount by which the intake valve 201a is pushed down is the lift amount of the valve, and the flow rate of air flowing from the intake valve to the combustion chamber increases or decreases in conjunction with the lift amount.

  In FIG. 4A, the minimum radius portion of the intake cam 305 is in contact with the input roller 405. At this time, the nose 401b and the rocker arm roller 406 are not in contact, so the intake valve 201a is opened. Not. On the other hand, in FIG. 4B, the maximum radius portion of the intake cam 305 is in contact with the input roller 405. At this time, the nose 401b and the rocker arm roller 406 are in contact, and the inclination angle of the nose 401b is further increased. Since the maximum inclination angle φ2 is, the lift amount of the intake valve 201a is also maximized.

Next, FIG. 5 shows a four-bar linkage mechanism in which the control arm 402 in FIG. 4 is inclined by φ1. In order to incline the control arm 402, when the variable valve transmission mechanism actuator 21 is the device shown in FIG. 8, the hydraulic control valve 22 supplies hydraulic oil to the first hydraulic chamber 21f to move the piston 21b to the left side. Move it. If the variable valve transmission actuator 21 is an electric motor, the control arm 402 fixed to the rotation control shaft may be rotated by rotating the electric motor.

  When the control arm 402 is rotated about the axis of the rotation control shaft 408, the relative position between the intake cam 305 and the input roller 405 varies. Specifically, in FIGS. 4A and 5A, the rotational phase of the intake cam 305 with respect to the intake shaft 306 is the same, but the contact point where the intake cam 305 and the input roller 405 contact each other is shown in FIG. In FIG. 4A, what was P1 moves to P2 in FIG. 5A. As a result, the opening / closing timing phase of the intake valve 201a with respect to the contour of the intake cam 305 is moved by the phase difference θ between the contact point P1 and the contact P2.

  On the other hand, when the control arm 402 rotates, the link posture of the four-bar linkage mechanism shown in FIG. 5 is different from the link posture shown in FIG. Specifically, when the minimum radius portion of the intake cam 305 is in contact with the input roller 405, the tilt angle of the nose 401b in FIG. Compared with the inclination angle, the right angle is moved by an angle corresponding to the angle φ1. Accordingly, when the maximum radius portion of the intake cam 305 contacts the input roller 405, the inclination angle φ3 of the nose 401b when the lift amount of the intake valve 201a is maximum is smaller than φ2. That is, the lift amount of the intake valve 201a in FIG. 5 is smaller than the lift amount of the intake valve 201a in FIG.

  Next, FIG. 10 shows the opening / closing characteristics of the intake valve by the variable valve mechanism according to the present invention. FIG. 10 shows the open / close characteristics of the intake valve 201a and the exhaust valve 203a when the control arm 402 is in the posture shown in FIG. 4 and in the posture shown in FIG. In FIG. 10, the horizontal axis indicates the time axis in the combustion cycle, and the vertical axis indicates the lift amounts of the intake valve 201a and the exhaust valve 203a. A curve 501 represents the exhaust characteristic of the exhaust valve 203a, and a curve 502 and a curve 503 represent the intake characteristic of the intake valve 201a. Here, a curve 502 is an intake characteristic in the variable valve transmission mechanism shown in FIG. 4, and a curve 503 is an intake characteristic in the variable valve transmission mechanism shown in FIG. That is, when the control arm 402 is rotationally driven from the state shown in FIG. 4 to the state shown in FIG.

  Here, as described above, the abutment point between the intake cam 305 and the input roller 405 shifts from P1 to P2, so that the relative position between the two changes, and the intake valve 201a has a contour relative to the contour of the intake cam 305. The valve timing phase will shift. In this embodiment, the phase difference between the contact points P1 and P2 corresponds to θ in FIG. In FIG. 10, θ is the difference between the center phase of the intake working angle represented by the curve 502 and the center phase of the intake working angle represented by the curve 503. That is, in this embodiment, the valve timing phase of the intake valve 201a is shifted to the advance side by changing the relative position between the intake cam 305 and the input roller 405. On the other hand, when the inclination angle of the nose 401b decreases from φ2 to φ3, the lift amount of the intake valve 201a decreases. The decrease in the lift amount is indicated by ΔL in FIG. ΔL is the difference between the lift amount at the center phase of the intake working angle represented by the curve 502 and the lift amount at the center phase of the intake working angle represented by the curve 503.

As in this embodiment, the four-bar linkage mechanism in the variable valve transmission mechanism is configured such that the valve timing phase advances toward the advance side as the lift amount of the intake valve 201a decreases, so that the intake valve 201a Even if the lift amount is variable, the valve opening timing can be made substantially the same, and the overlap amount of the operating angle of the exhaust valve 203a and the operating angle of the intake valve 201a can be made almost the same. Become.

  As described above, the variable valve mechanism of the internal combustion engine according to the present embodiment can simultaneously change the lift amount of the intake valve and the valve timing phase, which are the opening / closing characteristics of the intake valve, with one actuator.

  In the previous embodiment, the opening / closing of the intake valve 201a is controlled by the variable valve mechanism of the internal combustion engine according to the present invention. However, the present invention is also applicable to the exhaust valve 203a. It is also possible to apply to both valves of the exhaust valve 203a. FIG. 11 shows the opening and closing characteristics of the valve when the variable valve mechanism for the internal combustion engine according to the present invention is applied to both the intake and exhaust valves. Curves 504 and 505 indicate the opening / closing characteristics of the exhaust valve, and curves 506 and 507 indicate the opening / closing characteristics of the intake valve. Curves 504 and 506 represent opening / closing characteristics when the lift amount of both valves is the maximum value, and curves 505 and 507 represent opening / closing characteristics when the lift amount of both valves is the minimum value. Here, as described above, the opening / closing characteristics of the intake valve advance the valve timing phase toward the advance side as the lift amount decreases. On the other hand, for the exhaust valve, the valve timing phase is advanced to the retard side as the lift amount decreases. By configuring the four-bar linkage mechanism of the variable valve transmission mechanism in this way, the lift amount of each valve can be changed while making the overlap amount of the operating angle in the intake characteristics and the operating angle in the exhaust characteristics substantially the same. Can do.

  Further, by applying the variable valve mechanism of the internal combustion engine according to the present invention to the intake valve and the exhaust valve, the valve timing phase of both valves can be shifted to the advance side and the retard side, so that the intake characteristics It is possible to control the amount of overlap between the operating angle at and the operating angle in the exhaust characteristics.

  As shown in FIG. 12, the load region of the internal combustion engine can be classified into an idle region, a light load region, a medium load region, a high load low and medium speed rotation region, and a high speed and high load rotation region. In the idle region, the overlap amount is eliminated to prevent the exhaust from being blown back, to stabilize the combustion, and to stabilize the engine rotation. In the light load region, the overlap amount is minimized, the exhaust blow-back is suppressed, the combustion is stabilized, and the engine rotation is stabilized. In the medium load region, the overlap amount is slightly increased, the internal EGR rate is increased, and the pumping loss is reduced. In the high-load low-medium-speed rotation region, the overlap amount is maximized to improve the volume efficiency and increase the torque. In the high-load high-speed rotation region, the overlap amount is set to a medium level or more to improve the volume efficiency.

  Here, FIG. 13 shows an example of the valve opening / closing characteristics when the overlap amount is controlled in accordance with the load condition of the internal combustion engine. In the embodiment in FIG. 13, the load status of the internal combustion engine is classified into (a) idle region, (b) light load region and medium load region, and (c) high load low / medium speed rotation region and high load / high speed rotation region. Yes. (A) In the idle region, the lift amount of the intake / exhaust valve is lowered and the valve timing phase of each valve is shifted to eliminate the overlap amount. (B) In the light load region and the intermediate load region, the intake / exhaust valve While raising the lift amount to a medium level, the valve timing phase of each valve is shifted to make the overlap amount small. Furthermore, (c) In the high-load low-medium-speed rotation region and the high-load high-speed rotation region, the lift amount of the intake / exhaust valves is greatly increased and the valve timing phase of each valve is shifted to set a large overlap amount. Yes. As described above, in the variable valve mechanism for the internal combustion engine according to the present invention, it is possible to adjust the overlap amount according to the load state of the internal combustion engine. In this embodiment, the variable valve mechanism of the internal combustion engine according to the present invention is applied to both the intake and exhaust valves, but the overlap amount is adjusted by applying to either one of the valves. Also good.

  Here, in the variable valve transmission mechanism shown in FIGS. 4 and 5, the advance of the valve timing phase of the intake valve 201a with respect to the rotation angle of the control arm 402 that is driven to rotate about the rotation control shaft 408 by the rotation control shaft 408. FIG. 14 shows the relationship between the angular amount and the inclination angle of the nose 401b. The horizontal axis in FIG. 14 represents the rotation angle amount of the control arm 402, and the vertical axis represents the angle. Here, the graph 508 is a graph showing the relationship between the amount of advancement of the valve timing phase of the intake valve 201 a with respect to the amount of rotation angle of the control arm 402. A graph 509 is a graph showing the relationship between the rotation angle amount of the control arm 402 and the inclination angle of the nose 401 b.

  In this embodiment, the graph 508 is substantially a straight line, and there is almost linearity between the rotation angle amount of the control arm 402 and the advance amount of the valve timing phase. In such a case, when controlling the valve timing phase, the control of the valve timing phase becomes simple due to its linearity. The graph 509 is also almost a straight line, and there is almost linearity between the rotation angle amount of the control arm 402 and the inclination angle of the nose 401b. Since the valve lift amount of the intake valve 201a is determined by the inclination angle of the nose 401b, this linearity makes it easy to control the valve lift amount.

<Second embodiment>
Next, an embodiment of a variable valve mechanism according to the present invention in an internal combustion engine in which an intake valve of the internal combustion engine is constituted by two valves, a first valve and a second valve, will be described with reference to FIG. In the variable valve mechanism shown in FIG. 15, a variable valve transmission mechanism constituted by a four-bar link is applied to each of the first valve and the second valve, and the two variable valve mechanisms are used. A coupling mechanism for coupling the valve transmission mechanism is provided. The details will be described below.

  Input rollers 605a and 605b as input portions are in contact with intake cams 606a and 606b provided on an intake shaft 600 driven by a crankshaft of the internal combustion engine, respectively. The input roller 605a is provided on the input arm 604a, and the input roller 605b is provided on the input arm 604b. The input arm 604a is provided by a spring 613a, and the input arm 604b is provided by a spring 613b (not shown). It is urged to always contact the intake cam. Accordingly, when the intake cams 606a and 606b are rotationally driven, the input rollers 605a and 605b are driven following the contours of the intake cams, and the intake valves are opened and closed at the same time.

  When the intake valves are finally opened and closed by rotationally driving the intake cams 606a and 606b, the postures of the control arms 602a and 602b are maintained in principle. Here, the input arms 604a and 604b are swingably connected to the control arms 602a and 602b at J1a which is a joint of the four-bar linkage mechanism and J1b which is not shown. Accordingly, the input arms 604a and 604b swing around the joints J1a and J1b.

  Further, the input arms 604a and 604b are swingably connected to the transmission arms 603a and 603b at J2a and J2b which are joints of the four-bar linkage mechanism. Therefore, as the input arms 604a and 604b swing around the joints J1a and J1b, the transmission arms 603a and 603b swing around the joints J2a and J2b.

Further, the transmission arms 603a and 603b are one ends of the swing arms 601a and 601b, and are connected to the swing arms 601a and 601b so as to be swingable at a joint J3a of the four-bar linkage mechanism and a joint J3b (not shown). . Therefore, when the transmission arms 603a and 603b swing around the joints J2a and J2b, the driving force from each intake cam is transmitted to the swinging arms 601a and 601b via the joints J3a and J3b. The swing arms 601a and 601b are connected to the rotation control shaft 608 so as to be swingable. Therefore, the swing arms 601a and 601b swing around the rotation control shaft 608 by the driving force.

  Further, the swing arms 601a and 601b have noses 607a and 607b which are protrusions, and the noses 607a and 607b swing as the swing arms oscillate around the rotation control shaft 608. Further, the output portion for transmitting the driving force from each intake cam transmitted to the noses 607a and 607b to each intake valve is constituted by rocker arm rollers 609a and 609b, rocker arms 610a and 610b, an adjuster 611a and an unillustrated 611b. Is done.

  Here, the noses 607a and 607b contact the rocker arm rollers 609a and 609b depending on the postures of the swinging arms 601a and 601b. That is, when the inclination of each nose is small, each rocker arm roller comes into contact with the outer circumference of each swinging arm, and when the inclination of each nose increases, the rocker arm rollers 609a and 609b become nose 607a and 607b. It will abut.

  The rocker arm rollers 609a and 609b are provided on the rocker arms 610a and 610b, respectively. Further, the rocker arms 610a and 610b are supported by the adjusters 611a and 611b at the base ends, and are opposite to the base ends. The front end portion located on the side is connected to each intake valve via stem ends 612a and 612b. Therefore, as long as each nose has a small inclination and each rocker arm roller is in contact with the outer circumference of each rocking arm, each rocker arm roller cannot be pushed down. When the nose comes into contact with each rocker arm roller, each rocker arm roller is pushed down, each rocker arm swings about the base end, and each stem end descends. As each stem end is lowered, each intake valve is pushed down, so that each intake valve is opened. The amount by which each intake valve is pushed down is the lift amount of the valve, and the flow rate of air flowing from the intake valve to the combustion chamber increases or decreases in conjunction with the lift amount.

  Here, in the variable valve mechanism of the internal combustion engine in the present embodiment, a variable valve transmission mechanism responsible for opening and closing the first intake valve, and a variable valve transmission mechanism responsible for opening and closing the second intake valve; A connecting mechanism for connecting the two. FIG. 16 and FIG. 17 are schematic diagrams of the connection mechanism and the configuration of the control arms 602a and 602b on which the connection mechanism is installed, and the operation will be described.

  First, in FIG. 16, the rotation control shaft 608 is driven by the variable valve transmission mechanism actuator 21. Here, as described above, for example, the variable valve transmission mechanism actuator 21 may be the device shown in FIG. 8, an electric motor, or the like depending on the connection mode between the control arm and the rotation control shaft 608. The variable valve transmission mechanism actuator 21 is an electric motor. The variable valve transmission mechanism actuator 21 is installed on the outer wall 1 b of the internal combustion engine, and its output shaft is connected to the rotation control shaft 608. A cylindrical outer wall 608b concentric with the rotation control shaft 608 includes the rotation control shaft 608 in the axial direction. The cylindrical outer wall 608b is fixed to the outer wall 1b of the internal combustion engine. At this time, since the cylindrical outer wall 608b is fixed to the outer wall 1b of the internal combustion engine, no rotational motion is performed, and only the rotation control shaft 608 is rotated by the rotation of the variable valve transmission mechanism actuator 21 therein.

Further, the rotation control shaft 608 is connected to a control arm 602a that constitutes a link mechanism on the first intake valve side, and is driven to rotate as the rotation control shaft 608 rotates.
On the other hand, the control arm 602b constituting the link mechanism on the second intake valve side is connected to the cylindrical outer wall 608b in a swingable state. Accordingly, the control arm 602b is not directly driven to rotate by the rotation of the rotation control shaft 608. A fixed plate 614 is provided on the cylindrical outer wall 608b.

  Here, in the control arms 602a and 602b and the fixing plate 614, through holes are provided as 616a, 616b and 616c, respectively, and the control arms 602a and 602b or the control arm 602b and the fixing plate 614 are moved through these through holes. And a connecting pin 615 for connecting the two. Here, as shown in FIG. 16A, when the connecting pin 615 is between the through holes 616a and 616b, the control arms 602a and 602b are connected. Accordingly, the rotation operation of the rotation control shaft 608 is transmitted to the control arm 602b via the control arm 602a. As a result, since the link mechanism on the first intake valve side and the link mechanism on the second intake valve side have the same posture, the relative position between the first intake cam and the first input roller, the second intake cam, The position relative to the input roller is the same. Therefore, the opening / closing characteristics of the first intake valve and the second intake valve are the same.

  Further, as shown in FIG. 16B, when the connecting pin 615 is between the through holes 616b and 616c, the control arm 602b and the fixing plate 614 are connected. On the other hand, the connection between the control arms 602a and 602b is released. Therefore, although the control arm 602a is rotationally driven by the rotational operation of the rotation control shaft 608, the control arm 602b is not rotationally driven because it is fixed to the fixed plate 614. Therefore, by rotating the rotation control shaft 608, the opening / closing characteristics of the first intake valve can be changed, while the opening / closing characteristics of the second intake valve can be maintained constant.

  In the variable valve mechanism of the internal combustion engine configured as described above, the opening / closing characteristics of the first intake valve and the second intake valve are made the same, and the opening / closing characteristics of the first intake valve and the second intake valve are made different. And can be selectively executed. With this configuration, by making the opening / closing characteristics of the first intake valve and the second intake valve different, in particular, the lift amount of each valve, the intake flow rate can be made different to generate a swirl flow in the combustion chamber. It becomes possible. As a result, it is possible to stabilize the combustion in the combustion chamber. When it is not necessary to generate a swirling flow, the opening / closing characteristics of both intake valves may be made the same.

  Further, in this embodiment, when the second control arm 602b is fixed to the fixed plate 614, the control arm 602b is fixed to the fixed plate so that the operating angle of the second intake valve becomes the maximum value or the minimum value. 614 can be fixed. In this way, the difference in the intake amount between the first intake valve and the second intake valve can be set as large as possible, the strength of the swirling flow in the combustion chamber can be increased, Combustion stability can be efficiently achieved. In particular, when the control arm 602b is fixed to the fixed plate 614 so that the operating angle of the second intake valve becomes the maximum value, it is easy to cope with a case where a large intake / exhaust amount is required. Therefore, it is more preferable.

FIG. 17 shows another embodiment of the connecting mechanism. In FIG. 17, the variable valve transmission mechanism actuator 21 is installed on the outer wall 1 b of the internal combustion engine, and its output shaft is connected to the rotation control shaft 608. The variable valve transmission mechanism actuator 21 will be described as an electric motor as in the above-described embodiment. Further, the rotation control shaft 608 is connected to a control arm 602a that constitutes a link mechanism on the first intake valve side, and is driven to rotate as the rotation control shaft 608 rotates. On the other hand, the control arm 602b constituting the link mechanism on the second intake valve side is connected to the rotation control shaft 608 in a swingable state. Accordingly, the control arm 602b is not directly driven to rotate by the rotation of the rotation control shaft 608. A fixed plate 614 is provided on the rotation control shaft 608.

  Here, in the control arms 602a and 602b, through holes are provided as 616a and 616b, respectively, and a plurality of through holes 616c are provided in the fixing plate 614. Further, a connecting pin 615 for moving the through holes and connecting the control arms 602a and 602b or the control arm 602b and the fixing plate 614 is provided. Here, as shown in FIG. 17A, when the connecting pin 615 is between the through holes 616a and 616b, the control arms 602a and 602b are connected. Accordingly, the rotation operation of the rotation control shaft 608 is transmitted to the control arm 602b via the control arm 602a. As a result, since the link mechanism on the first intake valve side and the link mechanism on the second intake valve side have the same posture, the relative position between the first intake cam and the first input roller, the second intake cam, The position relative to the input roller is the same. Therefore, the opening / closing characteristics of the first intake valve and the second intake valve are the same.

  Further, as shown in FIG. 16B, when the connecting pin 615 is positioned only on the control arm 602b, only the control arm 602a is rotationally driven by the rotation of the rotation control shaft 608, and the control arm 602b maintains its posture. Keep doing. In addition, as shown in FIG. 16C, when the connecting pin 615 extends between the control arm 602 b and the fixed plate 614, when the rotation control shaft 608 is driven to rotate, the control arm 602 b moves together with the fixed plate 614. As long as the rotation control shaft 608 is stopped, the attitude of the control arm 602b is maintained, so that the opening / closing characteristics of the first intake valve do not fluctuate.

  In each control arm in the coupling mechanism and the link mechanism configured as described above, when the opening and closing characteristics of the first intake valve and the second intake valve are the same, as shown in FIG. 615 may be arranged. Next, in order to make the opening / closing characteristics of the first intake valve different from the second intake valve, first, the connection between the control arms 602a and 602b by the connection pin 615 is released as shown in FIG. Next, after rotating the rotation control shaft 608 to align with the control arm 602b and one of the plurality of through holes 616c provided in the fixing plate 614, the fixing plate 614 and the control arm are connected by the connecting pin 615. 602b is connected. At this time, the postures of the link mechanism including the control arm 602a and the link mechanism including the control arm 602b are different, and the difference is stepwise by the through-hole 616c selected in the connection between the control arm 602b and the fixing plate 614. It is possible to adjust to.

  In the variable valve mechanism of the internal combustion engine configured as described above, the opening / closing characteristics of the first intake valve and the second intake valve are made the same, and the opening / closing characteristics of the first intake valve and the second intake valve are made different. And can be selectively executed. With this configuration, by making the opening / closing characteristics of the first intake valve and the second intake valve different, in particular, the lift amount of each valve, the intake flow rate can be made different to generate a swirl flow in the combustion chamber. It becomes possible. As a result, it is possible to stabilize the combustion in the combustion chamber. When it is not necessary to generate a swirling flow, the opening / closing characteristics of both intake valves may be made the same.

<Third embodiment>
FIG. 18 shows another embodiment of the variable valve mechanism of the internal combustion engine in FIG. FIG. 18 is a longitudinal sectional view of the cylinder 2 of the internal combustion engine 1 including a suction port 202a and an exhaust port 204a.
In response to the signal from the accelerator pedal opening sensor 20 and the engine speed Ne of the internal combustion engine 1, the intake throttle valve 11 is opened by the operation of the intake throttle actuator 12,
By energizing the fuel injection valve 3, a required amount of air and fuel flow into the intake port 202a. Further, air and fuel in an amount corresponding to the lift amount of the intake valve 201 a flows into the combustion chamber 701. At this time, the intake valve 201a is opened and closed in four sections including a swing arm 801, a transmission arm 803, and an input arm 804 due to the rotation of the intake cam 705 provided on the intake cam shaft 706 as the internal combustion engine 1 rotates. Opening and closing is performed via a link or the like.

  In the variable valve train transmission mechanism that includes the link mechanism described above, the attitude of the entire link mechanism can be changed by controlling the attitude of the input arm 804. For example, the attitude of the input arm can be controlled by converting the rotation operation of the electric motor into a linear operation by a rack and pinion mechanism or the like and transmitting the linear operation of the rack to the input arm 804. The operation of the link mechanism will be described later.

  Further, the first exhaust valve 203 a that opens and closes the first exhaust port 204 a of the cylinder 2 is rotated via the rocker arm 710 by the rotation of the exhaust cam 708 provided on the exhaust camshaft 709 as the internal combustion engine 1 rotates. It is opened and closed with a certain lift amount.

  Here, a variable valve transmission mechanism that transmits the driving force of the intake cam 705 to the intake valve 201a and opens and closes the drive force will be described. 19 and 20 are detailed views of a main part of a variable valve transmission mechanism and an intake valve 201a that is controlled to be opened and closed by the variable valve transmission mechanism.

  Here, based on FIG. 19 and FIG. 20, operation | movement of the four-bar linkage mechanism which comprises a variable valve transmission mechanism is demonstrated. FIG. 19 is a diagram illustrating the operation of the four-bar link when the joints J4 and J7 in the four-bar link are positioned horizontally in the drawing. FIG. 20 is a diagram illustrating the operation of the four-joint link when the joint J4 is inclined to the right by φ4 from the position of FIG. 19A and 19B, (A) is an operation diagram of the four-bar link when the minimum radius portion of the intake cam 705 is in contact with the input roller 805, and (B) is an intake cam. FIG. 10 is an operation diagram of a four-bar link when a maximum radius portion of 705 is in contact with an input roller 805;

  First, the operation of the four-bar link in FIG. 19 will be described. An input roller 805 as an input portion is in contact with an intake cam 705 provided on an intake shaft 706 driven by a crankshaft of the internal combustion engine 1 at an abutment point P3 (P3 is a point on the intake cam). The input roller 805 is provided on the input arm 804 and is urged so that the input roller 805 always abuts against the intake cam 705. Therefore, when the intake cam 705 is driven to rotate, the input roller 805 is driven following the contour of the intake cam 705, and the intake valve 201a is opened and closed through the four-bar link.

  When the intake valve 201a is finally opened and closed by rotationally driving the intake cam 705, the position of the joint J4 of the four-bar linkage mechanism is maintained. In holding the joint J4, the motor is stopped by continuously sending an excitation command to the motor, or the rotation of the pinion in the rack and pinion mechanism 712 is stopped by a brake mechanism (not shown) provided inside or outside the motor. Good.

In the state where the position of the joint J4 of the four-bar linkage mechanism is maintained, the intake cam 705 is driven to rotate. When the maximum radius portion of the intake cam is in contact with the input roller 805 (the state of FIG. 19B), when the input roller 805 is pushed in and the minimum radius portion of the intake cam is in contact (see FIG. 19 (A)), the input roller 705 is pushed in the least amount. In this way, the intake cam 705 and the input roller 805 are always kept in contact with each other by the urging force of the spring 707. When the input roller 805 is pressed against the intake cam 705, the driving force from the intake cam 705 is transmitted to the input arm 804 where the input roller 805 is installed. Here, the input arm 804 is swingably supported at J4 which is a joint of the four-bar linkage mechanism. Accordingly, the input arm 804 swings around the joint J4.

  Further, the input arm 804 is swingably connected to the transmission arm 803 at J5 which is a joint of the four-bar linkage mechanism. Accordingly, as the input arm 804 swings about the joint J4, the transmission arm 803 swings about the joint J5.

  Further, the transmission arm 803 is one end of the swing arm 801 and is swingably connected to the swing arm 801 at a joint J6 of the four-bar linkage mechanism. Therefore, when the transmission arm 803 swings about the joint J5, the driving force from the intake cam is transmitted to the swing arm 801 via the joint J6. The swing arm 801 is supported so as to be swingable at the joint J7. Therefore, the swing arm 801 swings around the joint J7 by the driving force.

  The swing arm 801 has a nose 801b that is a protruding portion, and the nose 801b swings as the swing arm 801 swings around the joint J7. Further, the output unit that transmits the driving force from the intake cam 705 transmitted to the nose 801b to the intake valve 201a is configured by a rocker arm roller 806, a rocker arm 807, and an adjuster 704.

  Here, the nose 801 b comes into contact with the rocker arm roller 806 depending on the posture of the swing arm 801. That is, when the inclination of the nose 801b is small, the rocker arm roller 806 is in contact with the circumferential outer side 801c of the swing arm, and when the inclination of the nose 801b is increased, the rocker arm roller 806 is in contact with the nose 801b. It will be.

  The rocker arm roller 806 is provided on the rocker arm 807. Further, the rocker arm 807 is supported by an adjuster 704 at a base end portion thereof, and a stem end at a distal end portion opposite to the base end portion. It is connected to the intake valve 201 a via 703. Therefore, as long as the inclination of the nose 801b is small and the rocker arm roller 806 is in contact with the outer circumference 801c, the rocker arm roller 806 cannot be pushed down, but the inclination of the nose 801b increases so that the nose 801b becomes the rocker arm. When coming into contact with the roller 806, the rocker arm roller 806 is pushed down, the rocker arm 807 swings around the base end, and the stem end 703 descends. When the stem end 703 is lowered, the intake valve 201a is pushed down, so that the intake valve 201a is opened. The amount by which the intake valve 201a is pushed down is the lift amount of the valve, and the flow rate of air flowing from the intake valve to the combustion chamber increases or decreases in conjunction with the lift amount.

  In FIG. 19A, the minimum radius portion of the intake cam 705 is in contact with the input roller 805. At this time, the nose 801b and the rocker arm roller 806 are not in contact, so the intake valve 201a is opened. Not. On the other hand, in FIG. 19B, the maximum radius portion of the intake cam 705 is in contact with the input roller 805. At this time, the nose 801b and the rocker arm roller 806 are in contact, and the inclination angle of the nose 801b. Since the maximum inclination angle φ5 is, the lift amount of the intake valve 201a is also maximized.

Next, FIG. 20 shows a four-joint link mechanism in which the position of the joint J4 in FIG. 19 is inclined φ4 from the position of FIG. 19 about the joint J7. In order to change the position of the joint J4, the posture of the input arm 804 may be changed by the variable valve transmission mechanism actuator 21. Here, when the posture of the input arm 804 is changed, the relative position between the intake cam 705 and the input roller 805 varies. Specifically, in FIGS. 19A and 20A, the rotational phase of the intake cam 705 with respect to the intake shaft 706 is the same, but the contact point where the intake cam 705 and the input roller 805 contact each other is illustrated in FIG. What was P3 in 19 (A) moves to P4 in FIG. 20 (A). As a result, the opening / closing timing phase of the intake valve 201a with respect to the contour of the intake cam 705 moves by the phase difference θ between the contact point P3 and the contact P4.

  On the other hand, by changing the posture of the input arm 804, the link posture of the four-bar linkage mechanism shown in FIG. 20 is different from the link posture shown in FIG. Specifically, when the minimum radius portion of the intake cam 705 is in contact with the input roller 805, the position of the joint J4 tilts in the clockwise direction by an angle φ4 about the joint J7, so that the nose 801b in FIG. 19 is moved by an angle corresponding to the angle φ4 in the right rotation direction as compared with the inclination angle of FIG. Therefore, when the maximum radius portion of the intake cam 705 contacts the input roller 805, the inclination angle φ6 of the nose 801b when the lift amount of the intake valve 201a is maximized is smaller than φ5. That is, the lift amount of the intake valve 201a in FIG. 20 is smaller than the lift amount of the intake valve 201a in FIG.

As described above, the variable valve mechanism of the internal combustion engine in the present embodiment can simultaneously change the lift amount and valve timing phase of the intake valve, which are the opening / closing characteristics of the intake valve.
Further, in the present embodiment, when the variable valve transmission mechanism actuator 21 acts on the input arm 804 as a control point, the displacement between the control point and the advance amount of the valve timing phase is approximately between. It is possible to configure a four-bar linkage so as to have linearity. In such a case, when controlling the valve timing phase, the control of the valve timing phase becomes simple due to its linearity. In addition, a four-bar linkage mechanism can be configured to have substantially linearity between the displacement of the control point and the inclination angle of the nose 801b. Since the valve lift amount of the intake valve 201a is determined by the inclination angle of the nose 801b, this linearity makes it easy to control the valve lift amount.

<Fourth embodiment>
FIG. 21 shows another embodiment of the variable valve mechanism of the internal combustion engine in FIG. In FIG. 21, a variable valve transmission mechanism constituted by a four-bar link is applied to each of the first valve and the second valve, and the two variable valve transmission mechanisms are connected to each other. The variable valve mechanism with which the mechanism is provided is shown. The details will be described below.

  Input rollers 905a and 905b, which are input portions of the variable valve transmission mechanism, are in contact with intake cams 906a and 906b provided on an intake shaft 900 driven by a crankshaft of the internal combustion engine, respectively. Note that the input roller 905a is provided on the input arm 904a, and the input roller 905b is provided on the input arm 904b. The input arms 904a and 904b are each provided with springs 907a and 907b (not shown) so that each input roller always contacts each intake cam. It is energized to touch. Therefore, when the intake cams 906a and 906b are rotationally driven, the input rollers 905a and 905b swing following the contours of the intake cams, and the swings are transferred to the stem ends 912a and 912b. Communicate and open and close each intake valve.

When the intake valves are finally opened and closed by rotationally driving the intake cams 906a and 906b, the positions of the joint J4a and J4b (not shown) are in principle maintained. Here, the input arms 904a and 904b are J4a which are joints of a four-bar linkage mechanism.
And in J4b, it is supported so that rocking is possible. Accordingly, the input arms 904a and 904b swing around the joints J4a and J4b.

  Here, the input arms 904a and 904b are swingably connected to the transmission arms 903a and 903b at J5a and J5b which are joints of the four-bar linkage mechanism. Accordingly, when the input arms 904a and 904b are rotationally driven around the joints J4a and J4b, the transmission arms 903a and 903b swing around the joints J5a and J5b.

  Further, the transmission arms 903a and 903b are pivotally connected to the swing arms 901a and 901b at joints J6a and J6b of the four-bar linkage mechanism at one end of the swing arms 901a and 901b. Accordingly, when the transmission arms 903a and 903b swing around the joints J5a and J5b, the driving force from each intake cam is transmitted to the swinging arms 901a and 901b via the joint J6. The swing arms 901a and 901b are swingably supported at the joint J7. Therefore, the swing arms 901a and 901b swing around the joint J7 by the driving force.

  Further, the swing arms 901a and 901b have noses 907a and 907b which are protrusions, and the noses 907a and 907b also swing according to the swing about the joints J7a and J7b of each swing arm. Further, the output section for transmitting the driving force from each intake cam transmitted to the noses 907a and 907b to each intake valve is constituted by rocker arm rollers 909a and 909b, rocker arms 910a and 910b, an adjuster 911a and an unillustrated 911b. Is done.

  Here, the noses 907a and 907b come into contact with the rocker arm rollers 909a and 909b depending on the postures of the swinging arms 901a and 901b. That is, when the inclination of each nose is small, each rocker arm roller comes into contact with the outside of the circumference of each swing arm, and when the inclination of each nose increases, it comes into contact with the noses 907a and 907b.

  The rocker arm rollers 909a and 909b are provided on the rocker arms 910a and 910b, respectively. Further, the rocker arms 910a and 910b are supported by the adjusters 911a and 911b at the base ends, and are opposite to the base ends. The front end portion located on the side is connected to each intake valve via stem ends 912a and 912b. Therefore, as long as each nose has a small inclination and each rocker arm roller is in contact with the outer circumference of each rocking arm, each rocker arm roller cannot be pushed down. When the nose comes into contact with each rocker arm roller, each rocker arm roller is pushed down, each rocker arm swings about the base end, and each stem end descends. As each stem end is lowered, each intake valve is pushed down, so that each intake valve is opened. The amount by which each intake valve is pushed down is the lift amount of the valve, and the flow rate of air flowing from the intake valve to the combustion chamber increases or decreases in conjunction with the lift amount.

  Here, in the variable valve mechanism of the internal combustion engine in the present embodiment, a variable valve transmission mechanism responsible for opening and closing the first intake valve, and a variable valve transmission mechanism responsible for opening and closing the second intake valve; A connecting mechanism for connecting the two. FIG. 22 shows a schematic diagram of the configuration of the coupling mechanism and the input arms 904a and 904b, and the operation thereof will be described.

In FIG. 22, a pinion gear 712 a is installed at the output shaft tip of the variable valve transmission mechanism actuator 21, and a rack 712 b that meshes with the pinion gear 712 a is connected to the first input arm 904 a via the connecting member 920. is doing. A joint J4a in the link mechanism on the first intake valve side is provided at a location where the connecting member 920 is connected to the first input arm 904a. In this embodiment, the variable valve transmission mechanism actuator 21 is an electric motor. As the variable valve transmission mechanism actuator 21 rotates, the rack 712b moves linearly. Further, the input arm 904a is always moved linearly according to the rack 712b by the connecting member 920. In parallel with the input arm 904a, an input arm 905b on the second intake valve side and a fixed plate 914 are provided. The fixed plate 914 is a member independent of the link mechanism on the first intake valve side and the link mechanism on the second intake valve side, and is fixed regardless of the posture of the elements of each link mechanism.

  Here, in the input arms 904a and 904b and the fixing plate 914, through holes are provided as 916a, 916b and 916c, respectively, and the input arms 904a and 904b or the input arm 904a and the fixing plate 914 are moved through these through holes. And a connecting pin 915 for connecting the two. Here, as shown in FIG. 22A, when the connecting pin 915 is between the through holes 916a and 916b, the input arms 904a and 904b are connected. Accordingly, the linear motion of the rack 712b is transmitted to the input arm 904b via the input arm 904a. As a result, since the link mechanism on the first intake valve side and the link mechanism on the second intake valve side have the same posture, the relative position between the first intake cam and the first input roller, the second intake cam, The position relative to the input roller is the same. Therefore, the opening / closing characteristics of the first intake valve and the second intake valve are the same.

  Furthermore, as shown in FIG. 22B, when the connecting pin 915 is between the through holes 916b and 916c, the input arm 904b and the fixing plate 914 are connected. On the other hand, the connection between the control arms 904a and 904b is released. Therefore, although the input arm 904a is linearly driven by the linear motion of the rack 712b, the input arm 904b is not linearly driven because it is fixed to the fixed plate 914. Therefore, the open / close characteristic of the first intake valve can be changed by linearly driving the rack 712b, while the open / close characteristic of the second intake valve can be maintained constant.

  In the variable valve mechanism of the internal combustion engine configured as described above, the opening / closing characteristics of the first intake valve and the second intake valve are made the same, and the opening / closing characteristics of the first intake valve and the second intake valve are made different. And can be selectively executed. With this configuration, by making the opening / closing characteristics of the first intake valve and the second intake valve different, in particular, the lift amount of each valve, the intake flow rate can be made different to generate a swirl flow in the combustion chamber. It becomes possible. As a result, it is possible to stabilize the combustion in the combustion chamber. When it is not necessary to generate a swirling flow, the opening / closing characteristics of both intake valves may be made the same.

  Further, in this embodiment, when the second input arm 904b is fixed to the fixed plate 914, the input arm 904b is fixed to the fixed plate so that the operating angle of the second intake valve becomes the maximum value or the minimum value. 914 can be fixed. In this way, the difference in intake amount between the first intake valve and the second intake valve can be set as large as possible, the strength of the swirling flow in the combustion chamber can be increased, and the combustion chamber The stability of combustion can be efficiently achieved. In particular, when the input arm 904b is fixed to the fixed plate 914 so that the operating angle of the first intake valve becomes the maximum value, it is easy to cope with a case where a large amount of intake and exhaust is required. Therefore, it is more preferable.

<Fifth embodiment>
FIG. 23 shows another embodiment of the variable valve mechanism for the internal combustion engine according to the present invention shown in FIG. In the embodiments described above, the output unit that transmits the driving force from the rotating cam to the valve and opens and closes the valve is the rocker arm roller 406, the rocker arm 4.
In the embodiment shown in FIG. 23, the valve is opened and closed by transmitting the swing of the nose, which is a part of the swing arm, directly to the valve. In the configuration shown in FIG. 23 as well, the open / close characteristics such as the valve lift amount and the valve timing phase can be changed as in the above-described variable valve mechanism of the internal combustion engine.

1 is a block diagram showing a schematic configuration of an internal combustion engine to which a variable valve mechanism for an internal combustion engine according to the present embodiment is applied and its control system. It is a figure which shows schematic structure of the cylinder head vicinity of the internal combustion engine in the variable valve mechanism of the internal combustion engine which concerns on this Embodiment. It is a figure which shows schematic structure of the variable valve mechanism of the internal combustion engine which concerns on this Embodiment. It is a schematic block diagram of the link mechanism which mainly comprises the variable valve transmission mechanism in the variable valve mechanism of the internal combustion engine which concerns on this Embodiment. It is a schematic block diagram of the link mechanism which mainly comprises the variable valve transmission mechanism in the variable valve mechanism of the internal combustion engine which concerns on this Embodiment. It is a schematic block diagram of the arm which comprises a part of link mechanism which mainly comprises the variable valve transmission mechanism in the variable valve mechanism of the internal combustion engine which concerns on this Embodiment. It is a schematic block diagram of the control shaft which rotationally drives the arm shown in FIG. It is a schematic block diagram of the actuator which drives the control axis shown in FIG. It is a schematic block diagram which shows another Example of the actuator which drives the control shaft shown in FIG. It is a figure which shows the open / close characteristic of the intake / exhaust valve obtained by the variable valve mechanism of the internal combustion engine which concerns on this Embodiment. It is a figure in another Example which shows the opening / closing characteristic of the intake / exhaust valve obtained by the variable valve mechanism of the internal combustion engine which concerns on this Embodiment. It is a figure which shows the addition condition of an internal combustion engine. It is a figure which shows the opening / closing characteristic of the intake / exhaust valve obtained by control of the overlap amount by the variable valve mechanism of the internal combustion engine which concerns on this Embodiment. It is a figure which shows the correlation of each parameter of the link mechanism in the variable valve mechanism of the internal combustion engine which concerns on this Embodiment. It is a figure which shows the 2nd Example of the variable valve mechanism of the internal combustion engine which concerns on this Embodiment. It is a figure which shows schematic structure of the periphery of an actuator which controls the link mechanism in the 2nd Example shown in FIG. It is a figure in another Example which shows schematic structure of the periphery of an actuator which controls the link mechanism in 2nd Example shown in FIG. It is a figure which shows the 3rd Example of the variable valve mechanism of the internal combustion engine which concerns on this Embodiment. It is a schematic block diagram of the link mechanism which mainly comprises the variable valve transmission mechanism in the variable valve mechanism of the internal combustion engine which concerns on a 3rd Example. It is a schematic block diagram of the link mechanism which mainly comprises the variable valve transmission mechanism in the variable valve mechanism of the internal combustion engine which concerns on a 3rd Example. It is a figure which shows the 4th Example of the variable valve mechanism of the internal combustion engine which concerns on this Embodiment. It is a figure which shows schematic structure of the periphery of an actuator which controls the link mechanism in the 4th Example shown in FIG. It is a figure which shows the 5th Example of the variable valve mechanism of the internal combustion engine which concerns on this Embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Internal combustion engine 2 ... Cylinder 3 ... Fuel injection valve 21 ... Variable valve-transmission transmission mechanism actuator 201a ... First intake valve 201b ... Second intake valve 301, 701 ... Combustion chamber 305, 705 ... Intake cam 306, 706 ... Intake shaft 401, 801 ... Swing arm 401b, 801b ... Nose 402 ... Control arm 403, 803 ... Transmission arm 404, 804 ... Input arm 405, 805 ... Input roller 601a, 901a ... First swing arm 601b, 901b ... Second swing arm 602a ... First control arm 602b ... Second Control arm 603a, 903a ... first transmission arm 603b, 903b ... second transmission arm 604a, 904a ··· First input arm 604b, 904b ... second input arm 605a, 905a ... first input roller 605b, 905b ... second input roller 606a, 906a ... first intake cam 606b, 906b .... Second intake cams 607a, 907a ... First nose 607b, 907b ... Second nose 610a, 910a ... First rocker arm 610b, 910b ... Second rocker arm 614, 914 ... Fixing plate 615, 915 ... coupling mechanism

Claims (5)

A first rotary cam and a second rotary cam that are rotationally driven, and at least one of an intake side or an exhaust side in the same cylinder of the internal combustion engine is at least opened and closed by the first rotary cam; In an internal combustion engine composed of two valves, a second valve that is opened and closed by a rotating cam, a first variable valve transmission mechanism and a link each including at least the opening and closing characteristics of the first valve and the second valve, respectively. A variable valve mechanism for an internal combustion engine that is variable by a second variable valve transmission mechanism including the mechanism,
Link attitude control means for controlling the attitude of the link mechanism included in the first variable valve transmission mechanism;
A connecting means allowing the connection between the link mechanism wherein the link mechanism, wherein said first variable valve transmission mechanism includes a second variable valve transmission mechanism includes,
Connection control means for controlling connection or release of connection by the connection means in accordance with the operating state of the internal combustion engine;
A variable valve mechanism for an internal combustion engine, comprising: 2. The internal combustion engine according to claim 1, wherein the link mechanism included in the first variable valve transmission mechanism and the link mechanism included in the second variable valve transmission mechanism are link mechanisms having substantially the same shape. Variable valve mechanism. The link included in the second variable valve transmission mechanism when the connection between the link mechanism included in the first variable valve transmission mechanism and the link mechanism included in the second variable valve transmission mechanism is released by the connecting means. The variable valve for an internal combustion engine according to claim 1 or 2, further comprising fixing means for fixing the posture of the mechanism to a posture in which the opening / closing characteristic of the second valve is a predetermined opening / closing characteristic. mechanism. The predetermined opening / closing characteristic is an opening / closing characteristic in which an operating angle of the second valve becomes a maximum operating angle or a minimum operating angle in a change of the opening / closing characteristics by the second variable valve transmission mechanism. A variable valve mechanism for an internal combustion engine according to claim 3. The fixing means selectively fixes the posture of the link mechanism included in the second variable valve transmission mechanism to a posture corresponding to one opening / closing characteristic among the plurality of predetermined opening / closing characteristics. The variable valve mechanism for an internal combustion engine according to claim 3.

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