JP4537817B2 - Variable valve mechanism - Google Patents

Description

  The present invention relates to a variable valve mechanism, and more specifically to a variable valve mechanism for an internal combustion engine.

  As a variable valve mechanism for an internal combustion engine, for example, a technique described in Patent Document 1 is known. In the technique described in Patent Document 1, the movable parts such as the intermediate cam and the rocker arm move in accordance with the rotation of the rotating cam connected to the intake camshaft, and the intake valve is opened and closed accordingly. In addition, the lift amount of the intake valve becomes an expected value by displacing the above-described intermediate cam by an electric motor according to the driving state of the vehicle and moving the contact position between the rotary cam and the intermediate cam. I am doing so.

  However, in the variable valve mechanism of the internal combustion engine described in Patent Document 1, since one electric motor is used as an actuator for displacing the movable part (intermediate cam), the electric motor fails. In such a case, the movable part cannot be displaced, and the lift amount of the intake valve according to the operating state cannot be obtained, resulting in inconveniences such as a reduction in fuel consumption.

  Further, the movable part described above is connected to the movable part displacement shaft to be displaced, and the electric motor is connected to the end of the movable part displacement shaft. Therefore, when the movable part displacement shaft is rotated by the electric motor, an excessive torsional stress is generated on the movable part displacement shaft, and the movable part displacement shaft may be damaged.

Therefore, one electric motor is connected to the movable part through a reduction mechanism such as a worm gear at the center of the movable part displacement shaft, and the movable part (more precisely, the rocker arm of the movable part) is connected to the predetermined part. A technique has been proposed in which a spring that biases in a direction to be a position (default position) is provided (see, for example, Non-Patent Document 1). The predetermined position (default position) means, for example, a position of the movable part that can secure a lift amount of the intake valve required when the internal combustion engine is under a low load.
JP 2003-343228 A (paragraph 0045, FIG. 6) BM W Co., Ltd., Valvetronic (registered trademark), [online], BM W Co., Ltd. homepage, Products, innovation, [Search September 17, 2004], Internet <URL: http: // www .bmw.co.jp / Product / Innovation / bmwpower>

  In the variable valve mechanism for an internal combustion engine described in Non-Patent Document 1, since the electric motor is connected to the central portion of the movable portion displacement shaft, excessive torsional stress is hardly generated on the movable portion displacement shaft. Even when the motor is out of order, the movable part is forcibly moved to the default position by the spring, so that it is possible to ensure the necessary lift amount of the intake valve when the internal combustion engine is under a low load.

  However, since the urging force of the spring is always applied to the movable part, it is necessary to set a large output torque of the electric motor that displaces the movable part, resulting in problems such as an increase in the size of the electric motor.

  In any of the above-described techniques, since the movable part is displaced by one electric motor, a sufficient output torque can be obtained when the electric motor is frozen at the start of the vehicle in winter. There was an inconvenience that it could not be obtained.

  Accordingly, an object of the present invention is to solve the above-described problems, and in a variable valve mechanism that displaces the movable part by rotating the movable part displacement shaft by an electric motor, the movable part displacement shaft does not generate excessive torsional stress. In addition to being able to rotate, when the electric motor breaks down, the movable part can be moved to the default position without increasing the size of the electric motor, thus ensuring the necessary amount of lift for the intake valve, etc. The object is to provide a variable valve mechanism.

  In addition, even when the electric motor freezes at the start of the vehicle in winter, it is possible to obtain an output torque sufficient to rotate the movable part displacement shaft and to displace the movable part connected to the movable part displacement shaft. An object of the present invention is to provide a variable valve mechanism.

In order to solve the above-mentioned object, in claim 1, a rotating cam, a plurality of movable parts driven by the rotating cam, valves opened and closed by the plurality of movable parts, In a variable valve mechanism comprising at least a movable part displacement shaft for integrally displacing a plurality of movable parts, a plurality of electric motors are connected to the movable part displacement shaft comprising a single continuous shaft, The movable part displacement shaft is rotated by a plurality of electric motors, and at least one of the plurality of electric motors is arranged between the plurality of movable parts.

In the second aspect, the plurality of the electric motor, and configured to so that connecting to both ends of the movable portion displaced axis.

In the third aspect, together with the movable portion displaced shaft comprising a plurality of shaft member divided in the axial direction, the so that to connect the plurality of the electric motor to each of the plurality of shaft member Configured.

In the fourth aspect, the plurality of the electric motor, and configured to so that connecting to both ends of the plurality of shaft member. According to a fifth aspect of the present invention, at least one of the plurality of electric motors is arranged on the plurality of movable parts.

According to a sixth aspect of the present invention, the electric motor is configured to have a two-pole n-stator structure (n ≧ 2).

According to a seventh aspect of the present invention, the internal combustion engine is configured to be at least one of an intake valve and an exhaust valve.

In the variable valve mechanism according to claim 1, a plurality of electric motors are connected to a movable part displacement shaft composed of one continuous shaft for displacing the movable part, and the movable part is displaced by the plurality of electric motors. The shaft is rotated, and at least one of the plurality of electric motors is arranged between the plurality of movable portions, so that the movable portion displacement shaft is rotated without generating excessive torsional stress. In addition, even if one of the plurality of electric motors fails, the movable part can be moved to the default position by rotating the movable part displacement shaft by the remaining normal electric motor. Thus, the lift amount of the intake valve can be ensured as much as necessary.

  In addition, even when the electric motor freezes at the start of the vehicle in winter, by driving a plurality of electric motors with the maximum torque, an output torque sufficient to rotate the movable part displacement shaft can be obtained. The movable part connected to the movable part displacement axis can be displaced.

In the variable valve mechanism according to claim 2, since it is configured to so that connecting each of a plurality of electric motors at both ends of the movable portion displaced axes, in addition to the effects mentioned above, by rotating the movable portion displacement axis In this case, it is possible to better prevent an excessive torsional stress from being generated on the movable portion displacement axis.

In the variable valve mechanism according to claim 3, with the movable portion displaced shaft comprising a plurality of shaft member which is axially divided, to connect a plurality of the electric motor to each of the plurality of shaft member In addition to the effect described in claim 1, the shaft piece to which a normal electric motor is connected is provided even when one of the plurality of electric motors fails. It can be rotated as usual, whereby the movable part is displaced to a proper position, and the lift amount of the intake valve according to the operating state can be obtained.

  Specifically, when one of the plurality of electric motors fails, the shaft piece to which the failed electric motor is connected is rotated by another normal electric motor or a return spring. The movable part can be moved to the default position. That is, in the cylinder corresponding to the shaft piece to which the failed electric motor is connected, since the movable portion is in the default position, for example, the lift amount of the intake valve necessary when the internal combustion engine is under a low load can be secured. .

  On the other hand, the shaft piece to which only the remaining normal electric motor is connected is rotated as usual, and the movable part can be displaced to an appropriate position according to the operating state. That is, in the cylinder corresponding to the shaft piece to which only a normal electric motor is connected, the movable portion is displaced as usual, so that the lift amount of the intake valve according to the operating state can be obtained.

In the variable valve mechanism according to claim 4, a plurality of the electric motor, since it is configured to so that connecting to both ends of a plurality of shaft member, in addition to the effects described in claim 3, the shaft When the piece is rotated, excessive torsional stress can be prevented from being generated in the shaft piece. In the variable valve mechanism according to claim 5, since at least one of the plurality of electric motors is arranged in the plurality of movable portions, the cylinder is obtained by individually rotating the shaft piece. Can be individually set as the lift amount of the intake valve according to the operating state.

In the variable valve mechanism according to the sixth aspect of the invention , since the electric motor is configured to have the two-pole n-stator structure (n ≧ 2), in addition to the above-described effects, the torque is relatively small but high torque Therefore, even if the configuration includes a plurality of electric motors, it can be easily incorporated into the variable valve mechanism.

In the variable valve mechanism according to claim 7 , since the valve is configured to be at least one of an intake valve and an exhaust valve of the internal combustion engine, in addition to the above-described effect, the intake valve ( A lift amount corresponding to the operating state can be obtained in both the intake valve and the exhaust valve (exhaust valve).

  The best mode of a variable valve mechanism according to the present invention will be described below with reference to the accompanying drawings.

  FIG. 1 is a schematic view showing an internal combustion engine provided with a variable valve mechanism according to a first embodiment of the present invention.

  In FIG. 1, reference numeral 10 denotes an internal combustion engine (hereinafter referred to as “engine”), and the engine 10 is a four-cycle four-cylinder DOHC type gasoline engine. The engine 10 includes an intake pipe 12, and air taken from an air cleaner (not shown) in the intake pipe 12 flows through the intake manifold 14. When two intake valves 16 are opened in each cylinder, a combustion chamber ( (Not shown in FIG. 1).

  A throttle valve 18 is disposed in the intake pipe 12. The throttle valve 18 is connected to an actuator 22 composed of a stepping motor that operates according to the output of an ECU (Electronic Control Unit) 20. The throttle valve 18 is set so as to have a fully open opening at normal times, and therefore the intake air amount into the combustion chamber is adjusted by the lift amount of the intake valve 16.

  In the vicinity of the intake ports of the four cylinders 24, an injector (fuel injection valve) 26 is arranged. Gasoline fuel stored in a fuel tank (not shown) is pumped to the injector 26 through a fuel supply pipe (not shown), and is connected to the ECU 20 through a drive circuit 28. When a drive signal indicating the valve opening time is supplied from the ECU 20 to the drive circuit 28, the injector 26 opens, and the gasoline fuel corresponding to the valve opening time is injected into the sucked air. The injected gasoline fuel is mixed with the inflowing air to form an air-fuel mixture.

  A spark plug 30 is disposed in the vicinity of the intake valve 16. The spark plug 30 is connected to the ECU 20 via an ignition device 32 such as an igniter. The ignition device 32 generates a spark discharge between electrodes facing the combustion chamber in response to an ignition signal from the ECU 20, and ignites the air-fuel mixture to burn. Let

  Gas (exhaust gas) generated by combustion flows into the exhaust manifold 38 when the two exhaust valves 36 are opened in each cylinder. The exhaust manifold 38 gathers downstream and is connected to the exhaust pipe 40. The exhaust gas flows through the exhaust manifold 38 and the exhaust pipe 40, is purified by a catalyst device (not shown), and is then discharged outside the engine.

  A crank angle sensor (shown as “ENG rotation speed” in the figure) 44 is arranged near the crankshaft (not shown) of the engine 10, and a cylinder discrimination signal and TDC (top dead center) of each cylinder or its vicinity. And a crank angle signal for every 30 degrees of crank angle obtained by subdividing the TDC signal interval into six. Those outputs are input to the ECU 20.

  The ECU 20 includes a microcomputer including a CPU, a ROM, a RAM, an input circuit, an output circuit, and a counter. The ECU 20 counts the crank angle signal in the input signal and calculates (detects) the engine speed (ENG speed).

  An accelerator pedal (not shown) is arranged on the floor of a driver's seat (not shown) of the vehicle on which the engine 10 is mounted, and an accelerator opening sensor ("Accelerator opening" in the figure) 46) is provided to output a signal corresponding to the accelerator opening indicating the amount of depression of the driver's accelerator pedal. The output is also input to the ECU 20.

  An air flow meter 50 is disposed in the intake pipe 12 of the engine 10 and outputs a signal corresponding to the intake air amount indicating the engine load. An air-fuel ratio sensor 52 is disposed in the exhaust pipe 40 and outputs a signal corresponding to the actual air-fuel ratio in the exhaust gas. The outputs of these sensor groups are also input to the ECU 20.

  In addition, although the signal output from various sensors, such as a water temperature sensor, is also input into ECU20, it abbreviate | omitted for the simplification of illustration.

  The ECU 20 detects the driving state (high load, low load, etc.) of the vehicle based on the signals such as the above-mentioned ENG rotation speed, accelerator opening, and the like, and determines the lift amount of the intake valve 16 according to the detected driving state. calculate.

  A variable valve mechanism 56 is connected to the intake valve 16. A signal corresponding to the calculated lift amount is supplied from the ECU 20 to the variable valve mechanism 56 (more precisely, a drive circuit of an electric motor (described later) of the variable valve mechanism 56). As a result, the variable valve mechanism 56 is driven (precisely, a movable part (described later) of the variable valve mechanism 56 is displaced), so that the intake valve 16 depends on the calculated lift amount, in other words, the operating state. It can be opened and closed with a lift amount.

  FIG. 2 is a schematic view showing the variable valve mechanism 56 in the vicinity of the cylinder head of the engine 10, and FIG. 3 is an enlarged partial sectional view taken along line III-III in FIG.

  The variable valve mechanism 56 is connected to the intake camshaft 60 and the intake camshaft 60, and has a plurality of, specifically eight, intake-side rotations having an elliptical shape (in other words, a cam shape) when viewed from the side. The cam 62, a plurality of, specifically four, movable parts 64 driven in contact with the intake side rotating cam 62, the intake valve 16 opened and closed by each movable part 64, and the movable part 64 are displaced. A movable portion displacement shaft (control shaft) 66 and a plurality (four) of electric motors connected to the movable portion displacement shaft 66, more specifically, a relatively small electric motor 68 having a two-pole two-stator structure (see FIG. 3) (not shown). The four movable portions 64 are a first movable portion 64a, a second movable portion 64b, a third movable portion 64c, and a fourth movable portion 64d in order from the right side in FIG.

  The exhaust valve 36 is not connected to a variable valve mechanism. Therefore, the exhaust valve 36 is connected to the exhaust camshaft 70, and a plurality of (eight) exhaust-side rotating cams 72 having an elliptical shape (in other words, a cam shape) when viewed from the side rotate, When the protrusion 721 of the rotating cam 72 contacts the stem end 361 of the exhaust valve 36, it is moved downward in FIG. As a result, the exhaust manifold 38 and the combustion chamber 76 communicate with each other and exhaust gas is discharged.

  Hereinafter, the configuration and operation of each element of the variable valve mechanism 56 will be described in detail.

  The intake camshaft 60 is connected to a crankshaft (not shown) of the engine 10 via a timing chain (not shown). As a result, the intake camshaft 60 and the intake-side rotating cam 62 are rotated by transmitting the rotational movement of the crankshaft.

  Each of the first to fourth movable parts 64 a to 64 d includes a rocker arm 84 having two rollers 82 and a support member 86 that rotatably supports the rocker arm 84 with a rocker arm rotation shaft 841.

  The roller 82 of the rocker arm 84 is disposed at a position in contact with the intake side rotating cam 62 described above. Further, the part of the rocker arm 84 opposite to the roller 82 is brought into contact with the stem end 161 of the intake valve 16. As a result, the intake valve 16 is opened and closed by the rotation of the intake-side rotating cam 62 and the rocker arm 84 about the rocker arm rotation shaft 841.

  The opening / closing operation of the intake valve 16 will be specifically described with reference to FIG.

  FIG. 4 is an enlarged partial sectional view similar to FIG. 3, showing a state when the intake valve 16 is opened.

  When the intake side rotating cam 62 rotates in the direction of arrow A in the figure, and the protrusion 621 of the intake side rotating cam 62 contacts the rocker arm 84 (specifically, the roller 82 of the rocker arm 84), the rocker arm 84 becomes the rocker arm rotation shaft 841. 4 is rotated (moved) clockwise (indicated by arrow B) in FIG. As a result, the intake valve 16 is moved downward (indicated by arrow C), and thus the intake valve 16 is opened. As a result, the intake manifold 14 and the combustion chamber 76 communicate with each other and the air-fuel mixture flows.

  The description of the configuration and operation of the variable valve mechanism 56 will be continued.

  FIG. 5 is a perspective view showing the movable portion displacement shaft 66, the first to fourth movable portions 64 a to 64 d, and the electric motor 68.

  As shown in FIGS. 2 and 5, the support member 86 is connected and fixed by a movable portion displacement shaft 66, and four electric motors 68 are connected to the movable portion displacement shaft 66. As shown in FIGS. 2 and 5, the four electric motors 68 are arranged between the first movable part 64a and the second movable part 64b, between the third movable part 64c and the fourth movable part 64d, and The movable part displacement shaft 66 is connected (arranged) to both ends.

  As a result, when the movable portion displacement shaft 66 is rotated about the movable portion displacement axis rotation shaft 661 by each electric motor 68, the support member 86 is similarly rotated about the movable portion displacement axis rotation shaft 661 accordingly. To do.

  Next, the electric motor 68 will be described.

  6 is a perspective view of the electric motor 68, and FIG. 7 is an exploded perspective view of the electric motor shown in FIG.

  In this embodiment, as the electric motor 68, a torque motor having a two-pole, two-stator structure (an electric motor mainly intended to generate torque in a limited operating range at the installed position) is used. Those having a characteristic structure such as

  The electric motor 68 includes a rotor 92, a stator (more specifically, a stator core) 94, a coil 98 wound around a bobbin (coil bobbin) 96, and a cover 100 that covers them. In FIG. 6 and the like, the thickness of the conductive wire of the coil 98 is exaggerated.

  The rotor 92 has a cylindrical shape, and a permanent magnet 921 having two poles of N pole and S pole is disposed (formed) on the outer periphery thereof. A rotor core 922 made of laminated steel plates is disposed inside the permanent magnet 921, and the movable portion displacement shaft 66 is connected to the inside (center) thereof. The permanent magnet 921 is made of, for example, a rare earth magnet such as neodymium or samarium / cobalt, or a ferrite magnet.

  The stator 94 is divided into two stator pieces, that is, a first stator half 941 and a second stator half 942. The first and second stator halves 941 and 942 are molded by heating and compressing a dust core, that is, a ferrite powder having a high magnetic permeability together with an insulating binder. Each of the first and second stator half portions 941 and 942 includes a ring-shaped main body portion and a projecting portion projecting therefrom, and when combined, accommodates the coil 98 wound around the bobbin 96 therebetween. .

  The bobbin 96 is made of an insulating material such as resin, and is formed in a circular shape as shown in the drawing in accordance with the shapes of the first and second stator halves 941 and 942, and a circular hole 961 is formed in the center thereof. Established. A coil 98 made of a conductive wire is wound around the bobbin 96. Although not shown, the bobbin 96 is fixed by resin potting after the coil 98 is wound.

  The bobbin 96 is accommodated by inserting the central hole 961 into a cylinder formed by two projecting portions of the first and second stator halves 941 and 942. The rotor 92 having the permanent magnet 921 formed on the outer periphery is formed in a hole formed by two protrusions so as to penetrate the two combined first and second stator halves 941 and 942 and the bobbin 96. Arranged (accommodated) in a rotatable manner.

  Since the bobbin 96 is formed in a circular shape and is inserted into a cylinder concentric with the center of the first and second stator halves 941 and 942 having the same shape (ring shape), the combined first and second The coil 98 is concentric with the rotor 92 when housed within the two stator halves 941, 942.

  The cover 100 is disposed so as to cover the rotor 92, the stator 94, and the bobbin 96 around which the coil 98 is wound. The cover 100 is formed with a connector 104 having pins 102 that can be connected to a drive circuit (not shown) of an electric motor to which a signal from the ECU 20 is supplied. Further, the cover 100 is provided with an insertion hole 1001 through which the movable portion displacement shaft 66 is inserted.

  In the electric motor (torque motor) 68 shown in FIG. 6 and the like, the coil 98 forms a rotating magnetic field in each of the first and second stator halves 941 and 942 when energized and energized from an AC power source (not shown). In the illustrated electric motor 68, the magnetic path covers (encloses) the coil 98, so that the magnetic path can be shortened and the stator 94 can be made smaller and lighter. Even if it is the structure provided with two or more electric motors as an example, it can be easily integrated in the cylinder head vicinity (variable valve mechanism 56) where space is restricted.

  The details of the electric motor 68 shown in the drawing are described in detail in an application (Japanese Patent Application No. 2004-253862) filed separately by the applicant of the present invention, so that further explanation is omitted.

  Next, displacement (movement) of the movable part 64 by the movable part displacement shaft 66 will be described. FIG. 8 is an enlarged partial cross-sectional view similar to FIG. 3, showing a state when the movable part 64 is moved to the leftmost by the movable part displacement shaft 66.

  When the movable portion displacement shaft 66 is rotated counterclockwise in FIG. 8 about the movable portion displacement shaft rotation shaft 661 by each electric motor 68, the support member 86 is similarly moved along the movable portion displacement shaft rotation shaft 661. Is rotated (moved) in the direction of arrow D in FIG. When the support member 86 is moved, the rocker arm 84 that is rotatably supported by the support member 86 is also moved in the arrow E direction.

  When the rocker arm 84 is moved to the leftmost in this way, the roller 82 of the rocker arm 84 is moved to a position where it does not contact the projection 621 of the intake side rotating cam 62 as shown in FIG. That is, the rocker arm 84 is not rotated (moved) by the rotation of the intake side rotating cam 62. Therefore, the intake valve 16 is not moved downward in FIG. 8, and the intake valve 16 is not opened. In this manner, it is possible to maintain the closed state of the intake valve 16 regardless of the rotation of the intake side rotation cam 62 of the intake camshaft 60.

  As described above, the rocker arm 84 is moved by rotating the movable portion displacement shaft 66, and the intake side rotating cam 62 (more precisely, the protrusion 621 of the intake side rotating cam 62) and the rocker arm 84 (more precisely, The lift amount of the intake valve 16 can be adjusted by moving the contact position of the intake side rotating cam 62 with the roller 82).

  That is, the ECU 20 supplies a signal corresponding to the lift amount of the intake valve 16 calculated as described above to the drive circuit of the electric motor, and drives each electric motor 68. When the electric motor 68 is driven, the movable portion displacement shaft 66 is rotated to move the rocker arm 84, and the rocker arm 84 is moved to move the contact position between the intake side rotating cam 62 and the rocker arm 84. When the contact position is moved, the downward movement amount of the intake valve 16 can be changed. In other words, the lift amount of the intake valve 16 can be changed (adjusted). The lift amount can be a value corresponding to the driving state of the vehicle.

  Next, in the above-described variable valve mechanism 56, an operation when one of the plurality of electric motors 68 fails will be described.

  When the ECU 20 detects that one of the plurality of electric motors 68 has failed by a signal from the drive circuit of each electric motor, the ECU 20 moves the rocker arm 84 to the remaining normal drive circuit of the electric motor. Provides a signal to return to the default position.

  The drive circuit of the normal electric motor 68 to which the above signal is supplied drives the normal electric motor 68, thereby rotating the movable part displacement shaft 66 and moving the rocker arm 84 to the default position (predetermined position). .

  When the rocker arm 84 is in the default position, when the intake side rotation cam 62 rotates and the protrusion 621 of the intake side rotation cam 62 contacts the roller 82 of the rocker arm 84, the rocker arm 84 rotates about the rocker arm rotation shaft 841 ( Moved). As a result, the intake valve 16 is moved downward, and the intake valve 16 is opened. In this way, even if one of the plurality of electric motors 68 fails, the lift amount of the intake valve 16 is set to a required amount (for example, the lift amount of the intake valve required when the engine is under a low load). Only quantity).

  Next, the operation when the electric motor freezes at the start of the vehicle in winter will be described.

  When the ECU 20 detects that the electric motor 68 cannot obtain a sufficient output torque due to freezing or the like based on a signal from the drive circuit of each electric motor, the ECU 20 outputs the maximum torque to the drive circuits of the four electric motors. Supply the signal to

  Since it is configured as described above, even when the electric motor 68 is frozen at the start of the vehicle in winter, it is sufficient to rotate the movable portion displacement shaft 66 by driving the four electric motors 68 with the maximum torque. Output torque can be obtained, and the first to fourth movable parts 64a to 64d connected to the movable part displacement shaft 66 can be displaced to appropriate positions.

  As described above, in the variable valve mechanism according to the first embodiment of the present invention, the four electric motors 68 are connected to the movable part displacement shaft 66 for displacing the movable part 64, and the four electric motors 68 are connected. Since the movable part displacement shaft 66 is rotated by this, the movable part displacement shaft 66 can be rotated without generating an excessive torsional stress, and any one of the plurality of electric motors 68 can be electrically driven. Even if the motor fails, the movable portion 64, more precisely the rocker arm 84, can be moved to the default position by the remaining normal electric motor, and the lift amount of the intake valve 16 can be ensured as much as necessary.

  Further, even when the electric motor 68 freezes at the start of the vehicle in winter, the output torque sufficient to rotate the movable portion displacement shaft 66 is obtained by driving the four electric motors 68 with the maximum torque. The movable part 64 connected to the movable part displacement shaft 66 can be displaced.

  Further, since the plurality of electric motors 68 are connected to both ends of the movable portion displacement shaft 66, excessive torsional stress is generated in the movable portion displacement shaft 66 when the movable portion displacement shaft 66 is rotated. This can be better prevented.

  Further, since the plurality of electric motors 68 are configured to have a two-pole n-stator structure (n ≧ 2), they can output a high torque while being relatively small, and thus include a plurality of electric motors. Even such a configuration can be easily incorporated into the variable valve mechanism 56.

Further, it is arranged that connects the variable valve Organization 5 6 to the intake valve 16 of the engine, it is possible to obtain a lift amount corresponding to the operating state in the intake valve 16 of the engine.

  Next, a variable valve mechanism according to a second embodiment of the invention will be described.

  FIG. 9 is a schematic view similar to FIG. 2, which shows the vicinity of the cylinder head of the engine 10 and shows the variable valve mechanism 561 according to the second embodiment, and FIG. FIG. 6 is a perspective view similar to FIG. 5, showing the fourth movable parts 64 a to 64 d and the electric motor 68.

  When focusing on the differences from the first embodiment, the movable portion displacement shaft 66 is divided into two in the axial direction as well shown in FIG. In other words, the movable portion displacement shaft 66 is constituted by a plurality of, specifically, two shaft pieces 66a and 66b divided in the axial direction.

  The four electric motors 68 are connected to both ends of the two shaft pieces 66a and 66b, respectively.

  Since the second embodiment is configured as described above, when one of the plurality of electric motors 68 fails, only the shaft piece to which the failed electric motor is connected and only a normal electric motor. It is possible to rotate the shaft piece separately.

  That is, in the variable valve mechanism 561 according to the second embodiment, the movable portion displacement shaft 66 is composed of a plurality (two) of shaft pieces 66a and 66b divided in the axial direction, and four electric motors. Since the motor 68 is configured to be connected to each of the two shaft pieces 66a and 66b, even when one of the four electric motors 68 fails, a normal electric motor is connected. In addition, the shaft piece can be rotated as usual, whereby the movable portion 64, more precisely, the rocker arm 84 is displaced to an appropriate position, and the lift amount of the intake valve 16 corresponding to the operating state can be obtained. .

  Specifically, when one of the four electric motors 68 fails, the shaft piece to which the failed electric motor is connected is rotated by another normal electric motor to move the movable portion 64. More precisely, the rocker arm 84 can be moved to the default position. That is, in the cylinder corresponding to the shaft piece to which the failed electric motor is connected, since the movable portion 64 is in the default position, a necessary lift amount of the intake valve 16 can be ensured.

  On the other hand, the shaft piece to which only the remaining normal electric motor is connected is rotated as usual, and the movable portion 64, more precisely, the rocker arm 84 can be displaced to an appropriate position according to the operating state. That is, in the cylinder corresponding to the shaft piece to which only a normal electric motor is connected, the movable part is displaced as usual, so that the lift amount of the intake valve 16 according to the operating state can be obtained.

  Further, since the four electric motors 68 are configured to be connected to both ends of the two shaft pieces 66a and 66b, excessive torsional stress is generated when the shaft pieces 66a and 66b are rotated. , 66b can be further prevented.

  Next, a variable valve mechanism according to a third embodiment of the invention will be described.

  FIG. 11 is a schematic view similar to FIG. 2, which is shown near the cylinder head of the engine 10 and centering on the variable valve mechanism 562 according to the third embodiment. FIG. FIG. 6 is a perspective view similar to FIG. 5, showing the fourth movable parts 64 a to 64 d and the electric motor 68.

  Focusing on the differences from the first and second embodiments, the movable portion displacement shaft 66 is divided into two in the second embodiment, whereas the four in the third embodiment. It comprised so that it might divide into. In other words, the movable part displacement shafts 66 are divided so as to have the same number as the cylinders 24, and one shaft piece 66A, 66B, 66C, 66D is provided for each cylinder.

  Further, the four electric motors (not visible in FIG. 11) are connected to the four shaft pieces 66A, 66B, 66C, 66D, respectively, and as shown in FIG. 12, the first to fourth movable parts. It is connected (arranged) between the support members 86 of 64a, 64b, 64c, 64d.

  A plurality (two) of return springs 108 are arranged in the vicinity of the support member 86 of the first to fourth movable parts 64a, 64b, 64c, and 64d.

  One of the two return springs 108 arranged in the vicinity of the support member 86 of the first movable portion 64a is configured such that the shaft piece 66A rotates clockwise in FIG. 12 around the movable portion displacement shaft rotation shaft 66A1 (indicated by an arrow F). In addition, the first movable portion 64a (more precisely, the rocker arm 84 of the first movable portion 64a) is configured to be biased in the direction of the default position. The other return spring 108 includes a first movable portion 64a (more precisely, the first movable portion) in which the shaft piece 66A is counterclockwise (indicated by an arrow G) in FIG. 12 around the movable portion displacement shaft rotation shaft 66A1. The rocker arm 84a of 64a is configured to be biased in the direction of the default position.

  The two return springs 108 disposed near the support members 86 of the second to fourth movable portions 64b, 64c, and 64d are the same as the two return springs 108 of the first movable portion 64a. Composed.

  Since the third embodiment is configured as described above, when one of the plurality of electric motors 68 fails, a shaft piece to which the failed electric motor is connected and a normal electric motor are connected. It is possible to separately rotate the shaft pieces connected to each other, and individually rotate the shaft pieces to make the cylinders individually have the lift amount of the intake valve corresponding to the operating state.

  That is, in the variable valve mechanism 562 according to the third embodiment, the movable portion displacement shaft 66 is composed of a plurality (four) of shaft pieces 66A, 66B, 66C, 66D divided in the axial direction, Since the four electric motors 68 are configured to be connected to the shaft pieces 66A, 66B, 66C, and 66D, respectively, even if one of the four electric motors 68 fails, it is normal. The shaft piece to which the electric motor is connected can be rotated as usual, whereby the movable portion 64, more precisely, the rocker arm 84 is displaced to an appropriate position, and the lift amount of the intake valve 16 according to the operating state. Can be obtained.

  Specifically, when one of the four electric motors 68 fails, the shaft piece to which the failed electric motor is connected is rotated by the return spring 108 to move the movable portion 64 (exactly Can move the rocker arm 84) of the movable part 64 to the default position. That is, in the cylinder corresponding to the shaft piece to which the failed electric motor is connected, since the movable portion 64 is in the default position, a necessary lift amount of the intake valve 16 can be ensured.

  On the other hand, the shaft piece to which the normal electric motor is connected is rotated as usual, and the movable portion 64, more precisely, the rocker arm 84 can be displaced to an appropriate position according to the operating state. That is, in the cylinder corresponding to the shaft piece to which the normal electric motor is connected, the movable portion is displaced as usual, so that the lift amount of the intake valve 16 according to the operating state can be obtained.

  Next, a variable valve mechanism according to a fourth embodiment of the invention will be described.

  FIG. 13 is a schematic view similar to FIG. 2, which shows the vicinity of the cylinder head of the engine 10 and mainly shows the variable valve mechanism according to the fourth embodiment, and FIG. 14 is an enlarged view of the XIV-XIV line of FIG. 13. It is a fragmentary sectional view.

  Description will be made focusing on the differences from the first to third embodiments. In the variable valve mechanism according to the fourth embodiment, the variable valve mechanism is not limited to the intake valve 16 but the exhaust valve 36. Also configured to be connected.

  Hereinafter, the configuration and operation of the variable valve mechanism 563 on the exhaust side will be described.

  The variable valve mechanism 563 on the exhaust side is connected to the exhaust camshaft 70 and the exhaust camshaft 70, and has a plurality of, more specifically, eight, which are elliptical in side view (in other words, cam shape). Exhaust-side rotating cam 72, a plurality of, specifically four, exhaust-side movable parts 164 driven in contact with exhaust-side rotary cam 72, and an exhaust valve 36 that is opened and closed by each exhaust-side movable part 164 , An exhaust side movable part displacement axis (movable part displacement axis, control shaft) 166 for displacing the exhaust side movable part 164, and a plurality (four) of electric motors connected to the exhaust side movable part displacement shaft 166, more specifically Specifically, a relatively small electric motor 168 (not shown in FIG. 14) having a two-pole two-stator structure similar to that on the intake side is provided. The four exhaust-side movable parts 164 are arranged in order from the right side in FIG. 13, the first exhaust-side movable part 164a, the second exhaust-side movable part 164b, the third exhaust-side movable part 164c, and the fourth exhaust gas. A side movable portion 164d is used.

  Each of the first to fourth exhaust-side movable parts 164a to 164d includes an exhaust-side rocker arm 184 having two rollers 182 and a support member 186 that rotatably supports the exhaust-side rocker arm 184 with a rocker arm rotation shaft 1841. .

  The roller 182 of the exhaust side rocker arm 184 is disposed at a position where it abuts on the exhaust side rotation cam 72 described above. Further, a portion of the exhaust side rocker arm 184 opposite to the roller 182 is brought into contact with the stem end 361 of the exhaust valve 36. As a result, the exhaust valve 36 is opened and closed as the exhaust side rotating cam 72 rotates, so that the exhaust side rocker arm 184 moves around the exhaust side rocker arm rotation shaft 1841 as in the intake side.

  Specifically, the exhaust-side rotating cam 72 rotates in the direction of arrow H in FIG. 14, and the protrusion 721 of the exhaust-side rotating cam 72 contacts the exhaust-side rocker arm 184 (specifically, the roller 182 of the exhaust-side rocker arm 184). Upon contact, the exhaust rocker arm 184 is rotated (moved) counterclockwise (indicated by arrow I) in FIG. 14 about the exhaust rocker arm rotation shaft 1841. As a result, the exhaust valve 36 is moved downward (indicated by an arrow J), so that the exhaust valve 36 is opened.

  The configuration and operation of the other exhaust-side variable valve mechanism 563 are substantially the same as those of the intake-side variable valve mechanism 56 according to the first embodiment, and a description thereof will be omitted.

  Since the fourth embodiment is configured as described above, not only the intake valve 16 of the engine but also the exhaust valve 36 can obtain a lift amount corresponding to the operating state.

As described above, in the first to fourth embodiments of the present invention, the rotating cam (intake side rotating cam 62 and exhaust side rotating cam 72) and a plurality of movable parts (movable) driven by the rotating cam are provided. Part 64, exhaust side movable part 164), valves (intake valve 16 and exhaust valve 36) respectively opened and closed by the plurality of movable parts, and a movable part displacement shaft for integrally displacing the plurality of movable parts. In the variable valve mechanism (56, 561, 562, 563) comprising at least (movable part displacement shaft 66, exhaust side movable part displacement shaft 166), a plurality of movable part displacement shafts comprising one continuous shaft are provided. And the movable part displacement shaft is rotated by the plurality of electric motors, and at least one of the plurality of electric motors is interposed between the plurality of movable parts. To be placed in Made.

The first of the present invention, in the second and fourth embodiments, the plurality of the electric motor (68,168), to connect to both ends of the movable portion displaced shaft (66, 166) It was configured as follows.

In the second and third embodiments of the present invention, a plurality of shaft pieces (shaft pieces 66a, 66b or shaft pieces 66A, 66B, 66C, together consisting 66D), and the said plurality of electric motor (68) configured to so that to connect to each of the plurality of shaft member.

Further, in the second embodiment of the present invention, the plurality of the electric motor (68), said plurality of axial strips (66a, 66b) and configured to so that connecting each end of. In the third embodiment of the present invention, at least one of the plurality of electric motors (68) is replaced with the plurality of movable parts (specifically, the first to fourth movable parts 64a, 64a, 64b, 64c, 64d) between the supporting members 86).

  In the first to fourth embodiments of the present invention, the electric motor (68, 168) is configured to have a two-pole n-stator structure (n ≧ 2).

  The valve is configured to be at least one of an intake valve (intake valve 16) and an exhaust valve (exhaust valve 36) of the internal combustion engine.

  In the above description, the electric motors 68 and 168 are used as actuators of the variable valve mechanism, and a torque motor having a characteristic structure is used as the electric motors 68 and 168. However, the variable valve mechanism according to the present invention is The actuator is not limited, and any actuator can be used.

  In addition, although the electric motors 68 and 168 are configured as two-pole two-stator, it is possible to form a two-pole four-stator by stacking the stators 94 having the same structure in the axial direction of the rotor 92 with a phase shifted by 90 degrees. is there. Further, a two-pole six-stator can be formed by laminating a stator having the same structure on the top thereof with a phase shifted by 120 degrees (in this case, a three-phase motor is obtained). Furthermore, a large number of stators 94 can be stacked while shifting the phase. From this point of view, it is described in the claims as “a motor having a two-pole n-stator structure (n ≧ 2)”.

  Further, although the stator 92 is divided into two stator pieces (stator half portions), when combined, the stator 92 can be divided into three or more stator pieces as long as a coil can be accommodated therebetween.

  The four electric motors 68 are connected to the movable part displacement shaft 66 or the exhaust side movable part displacement shaft 166, respectively. However, the present invention is not limited to this, and two, three, or five or more are provided. Needless to say, it may be.

  In the fourth embodiment, the variable valve mechanism 563 is connected to the exhaust valve 36 of the first embodiment, but the variable valve mechanism is connected to the exhaust valve 36 of the second and third embodiments. In other words, the exhaust-side movable portion displacement shaft 166 includes a plurality of shaft pieces divided in the axial direction, and the plurality of electric motors 168 may be connected to each of the plurality of shaft pieces. Needless to say, it is good.

  In the fourth embodiment, the intake-side variable valve mechanism 56 and the exhaust-side variable valve mechanism 563 are configured to have substantially the same shape, but the exhaust-side rotary cam 72 or the exhaust-side movable portion 164 has the same shape. The shape may be appropriately different from that of the intake side rotating cam 62 or the intake side movable portion 64.

  In the fourth embodiment, based on the engine load, the engine operation is switched between all-cylinder operation in which all the cylinders are operated and rest-cylinder operation in which some of the operations are suspended to thereby reduce fuel consumption. The present invention can also be applied to a cylinder deactivation engine that reduces the number of cylinders.

  That is, when the ECU 20 detects that it is necessary to perform the cylinder idle operation, the electric motors 68 and 168 corresponding to the cylinder to be cylinder idled are driven to move the movable portion 64 and the exhaust side movable portion 164. To this end, the roller 82 of the rocker arm 84 and the roller 182 of the exhaust side rocker arm 184 are moved to positions where they do not contact the intake side rotary cam 62 and the exhaust side rotary cam 72. Thus, the rocker arm 84 and the exhaust side rocker arm 184 are not rotated (moved) by the intake side rotation cam 62 and the exhaust side rotation cam 72, and therefore the intake valve 16 and the exhaust valve 36 are not opened but are closed. Since the state can be maintained, it can be applied to a cylinder deactivation engine.

1 is a schematic view showing an internal combustion engine provided with a variable valve mechanism according to a first embodiment of the present invention. FIG. 2 is a schematic view around a variable valve mechanism in the vicinity of the cylinder head of the engine shown in FIG. 1. FIG. 3 is an enlarged partial sectional view taken along line III-III in FIG. 2. FIG. 4 is an enlarged partial sectional view similar to FIG. 3, showing a state when the intake valve shown in FIG. 2 is opened. It is a perspective view which shows the movable part displacement axis | shaft shown in FIG. 2, a movable part, and an electric motor. It is a perspective view of the electric motor shown in FIG. FIG. 7 is an exploded perspective view of the electric motor shown in FIG. 6. FIG. 4 is an enlarged partial cross-sectional view similar to FIG. 3, showing a state when the rocker arm shown in FIG. 2 is moved to the left most. FIG. 3 is a schematic view similar to FIG. 2, mainly showing a variable valve mechanism according to a second embodiment of the present invention. It is a perspective view similar to FIG. 5 which shows the movable part displacement axis | shaft, movable part, and electric motor which are shown in FIG. FIG. 6 is a schematic view similar to FIG. 2, mainly showing a variable valve mechanism according to a third embodiment of the present invention. It is a perspective view similar to FIG. 5 which shows the movable part displacement axis | shaft, movable part, and electric motor which are shown in FIG. FIG. 6 is a schematic view similar to FIG. 2, mainly showing a variable valve mechanism according to a fourth embodiment of the present invention. It is the XIV-XIV line expanded partial sectional view of FIG.

Explanation of symbols

16 Intake valve
36 Exhaust valve (valve)
56 Variable valve mechanism (of the first and fourth embodiments) 62 Intake side rotating cam (rotating cam)
64 Movable portion 66 Movable portion displacement shaft 66a, 66b (second embodiment) shaft piece 66A, 66B, 66C, 66D (third embodiment) shaft piece 68 (intake side) electric motor 72 exhaust side rotating cam ( Rotating cam)
164 Exhaust side movable part (movable part)
166 Exhaust- side movable part displacement axis (movable part displacement axis)
168 (exhaust side) electric motor 561 (second embodiment) variable valve mechanism 562 (third embodiment) variable valve mechanism 563 (fourth embodiment exhaust side) variable valve mechanism

Claims (7)

A rotating cam; a plurality of movable parts driven by the rotating cam; a valve opened and closed by each of the plurality of movable parts; and a movable part displacement shaft for integrally displacing the plurality of movable parts. In at least the variable valve mechanism, a plurality of electric motors are connected to the movable part displacement shaft composed of one continuous shaft, the movable part displacement shafts are rotated by the plurality of electric motors, and the plurality A variable valve mechanism characterized in that at least one of the electric motors is disposed between the plurality of movable parts.   The variable valve mechanism according to claim 1, wherein the plurality of electric motors are respectively connected to both ends of the movable portion displacement shaft.   The movable part displacement shaft is composed of a plurality of shaft pieces divided in the axial direction, and the plurality of electric motors are connected to the plurality of shaft pieces, respectively. Variable valve mechanism.   The variable valve mechanism according to claim 3, wherein the plurality of electric motors are respectively connected to both ends of the plurality of shaft pieces.   The variable valve mechanism according to claim 3, wherein at least one of the plurality of electric motors is disposed on the plurality of movable portions.   The variable valve mechanism according to claim 1, wherein the electric motor has a two-pole n-stator structure (n ≧ 2).   The variable valve mechanism according to claim 1, wherein the valve is at least one of an intake valve and an exhaust valve of an internal combustion engine.

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