JP2009203869A - Valve timing control system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a valve timing control system securing startability of an internal combustion engine and controllability of valve timing. <P>SOLUTION: The valve timing control system 10 controls valve timing of intake valves opened and closed by camshafts 4 in the internal combustion engine 1 wherein fluctuating torque of mutually shifted alternating phases act on a pair of the camshafts 4. It is equipped with an electromagnetic actuator 60 having an output rotary shaft 62 under the action of magnetism retention torque and generating output torque to the output rotary shaft 62 by energization, an energization control circuit part 80 controlling rotation of the output rotary shaft 62 by the energization to the electromagnetic actuator 60 and cutting of the energization to the electromagnetic actuator 60 following stopping of the internal combustion engine 1, and a pair of phase adjusting mechanisms 12 adjusting rotation phases of the connected camshafts 4 with respect to a crankshaft 3 in response to a rotating state of the output rotary shaft 62 while transmitting the fluctuating torque to the connected output rotary shaft 62 in common from the individually connected camshafts 4. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a technique for controlling the valve timing of a valve that opens and closes a camshaft by torque transmission from a crankshaft in an internal combustion engine.

  Conventionally, the rotational phase of the camshaft relative to the crankshaft (hereinafter, “the rotational phase of the camshaft relative to the crankshaft” is also simply referred to as “the rotational phase of the camshaft”) is adjusted by using the output torque from the electromagnetic actuator. A technique for realizing a desired valve timing is known.

As one of the technologies, Patent Document 1 discloses that an output motor shaft can be magnetically held by a cogging torque as a magnetic holding torque in an electric motor as an electromagnetic actuator that is energized and cut off when the internal combustion engine is stopped. A valve timing control device is disclosed. Here, in general, a fluctuation torque having an alternating phase acts on the camshaft due to a spring reaction force of the valve, etc. In the device disclosed in Patent Document 1, the energization is cut off through the phase adjustment mechanism. Even if the varying torque is transmitted to the output rotating shaft, the output rotating shaft can be held by the cogging torque that overcomes the varying torque. Therefore, the rotation phase of the camshaft suitable for starting the internal combustion engine (hereinafter, the “rotation phase of the camshaft suitable for starting” is simply referred to as “starting phase”) is maintained at the next engine start by holding the output rotation shaft. Can be secured.
JP 2008-2362 A

  By the way, in the apparatus disclosed in Patent Document 1, the peak value of the cogging torque is made larger than the absolute value of the cam torque acting on the output rotation shaft by transmission from the cam shaft, thereby enabling the output rotation shaft to be held. . Therefore, when the absolute value of the cam torque increases due to an increase in the spring reaction force of the valve, etc., the peak value of the cogging torque must be increased accordingly. Such a large cogging torque is a factor that deteriorates the rotation controllability of the output rotation shaft due to energization, and is not desirable in controlling the valve timing by adjusting the rotation phase of the cam shaft according to the rotation state of the output rotation shaft. is there.

  Further, when the device disclosed in Patent Document 1 is applied to an internal combustion engine having a plurality of cam shafts such as a V-type internal combustion engine, the phase adjusting mechanism of the device is individually connected to each of the cam shafts. It is assumed that In this case, if the electric motor of one device breaks down and the rotation control of the output rotation shaft is hindered, there is a problem that the rotation phase of each cam shaft is shifted and it is difficult to start the internal combustion engine. There is concern.

  The present invention has been made in view of the problems described above, and an object of the present invention is to provide a valve timing control system that ensures both the startability of the internal combustion engine and the controllability of the valve timing.

  According to the first aspect of the present invention, in an internal combustion engine in which alternating phase fluctuating torques acting on a plurality of camshafts act on a plurality of camshafts, the valve timings of the valve valves that each camshaft drives to open and close by torque transmission from the crankshaft A valve timing control system that controls an electromagnetic actuator that has an output rotation shaft on which a magnetic holding torque acts, generates an output torque on the output rotation shaft by energization, and rotates the output rotation shaft by energizing the electromagnetic actuator And a variable torque from the connection cam shaft as the cam shaft connected individually to the output rotation shaft connected in common to the power supply control means for cutting off the power supply to the electromagnetic actuator when the internal combustion engine stops. A plurality of phase adjustment mechanisms that adjust the rotational phase of the connecting camshaft according to the rotational state of the output rotary shaft while transmitting That.

  According to the present invention, the fluctuation torque acting at the alternating phase shifted from each other with respect to the connecting cam shaft individually connected to each phase adjusting mechanism is transmitted to the output rotating shaft through each phase adjusting mechanism. In such an output rotation shaft, it is possible to cancel the varying torques acting from each phase adjusting mechanism with each other in accordance with the shift of the alternating phase and reduce the combined torque of these varying torques. Therefore, according to the magnetic holding torque that acts on the output rotating shaft in the electromagnetic actuator that is cut off when the internal combustion engine is stopped, it is possible to overcome the combined torque of the variable torque even if the magnitude is small. In this case, the output rotation shaft can be held at a position where the rotation phase of each connection cam shaft is the starting phase.

  In addition, in the first aspect of the present invention, each phase adjusting mechanism is connected to a separate output camshaft while being connected to an individual connecting camshaft. Even if the rotation control is hindered, the rotational phase shift of each connecting cam shaft does not substantially occur. Therefore, it is possible to avoid a situation in which the internal combustion engine is difficult to start due to a shift in the rotational phase of each connecting camshaft.

  According to the first aspect of the present invention described above, not only the startability of the internal combustion engine is ensured, but also the controllability of the valve timing is ensured by a small magnetic holding torque.

  According to the second aspect of the present invention, the fluctuating torque transmitted from the connection cam shaft to the output rotating shaft through each of the pair of phase adjusting mechanisms is out of phase with each other. According to this, in the output rotating shaft, the fluctuation torques having opposite phases acting from each of the pair of phase adjustment mechanisms can be surely canceled out, so that the effect of reducing the combined torque of these fluctuation torques becomes high. Therefore, in order to maintain the rotational phase of each connecting camshaft at the starting phase, the magnetic holding torque that overcomes the combined torque of the variable torque can be reduced as much as possible to improve the controllability of the valve timing. .

  According to the third aspect of the present invention, each phase adjusting mechanism transmits the varying torque from the connecting cam shaft to the output rotating shaft among the pair of cam shafts provided in the V-type internal combustion engine. Here, in general, in a V-type internal combustion engine, by varying the ignition timing between the cylinders of each bank, a fluctuation torque having an opposite phase acts on each of the pair of camshafts. Therefore, the magnetic holding torque that overcomes the combined torque of the variable torque transmitted from the connecting camshaft and acting on the output rotating shaft among the camshafts of the V-type internal combustion engine is reliably reduced, and the valve timing controllability is reduced. The improvement effect can be made solid.

  According to a fourth aspect of the present invention, the electromagnetic actuator is an electric motor that generates a motor torque as an output torque on an output rotating shaft on which a cogging torque as a magnetic holding torque acts. Here, since the cogging torque that magnetically holds the rotating shaft by acting on the output rotating shaft as the magnetic holding torque can be generated by the basic magnetic structure of the electric motor, the size and cost of the system are increased. The startability of the internal combustion engine and the controllability of the valve timing can be improved without incurring an increase. In addition, since the motor torque generated by the electric motor as the output torque on the output rotating shaft can be accurately controlled by energization, the controllability of the output rotating shaft and thus the controllability of the valve timing is improved by such accurate energization control. It can also be done.

  According to the fifth aspect of the present invention, the electromagnetic actuator is disposed between the pair of phase adjusting mechanisms that are coaxially connected to the connection cam shaft among the pair of cam shafts parallel to each other. According to this, since the electromagnetic actuator can be arranged by effectively using the space generated between the pair of connecting cam shafts parallel to each other and the coaxial phase adjusting mechanism, the internal combustion engine including the valve timing control system can be arranged. The overall size of the engine can be reduced.

  Hereinafter, a plurality of embodiments of the present invention will be described with reference to the drawings. In addition, the overlapping description is abbreviate | omitted by attaching | subjecting the same code | symbol to the corresponding component in each embodiment.

(First embodiment)
FIG. 1 shows an example in which a valve timing control system (hereinafter, “valve timing control system” is simply referred to as “control system”) 10 is applied to an internal combustion engine 1 for a vehicle as a first embodiment of the present invention. .

(Internal combustion engine)
The internal combustion engine 1 is a V-type engine in which a right bank 2R and a left bank 2L are arranged in a V shape, and outputs the engine torque of the crankshaft 3 to a transaxle (not shown) of the vehicle. In this embodiment, the internal combustion engine 1 forms three cylinders in each of the banks 2R and 2L that form approximately 60 degrees, and the intake camshaft 4 and the exhaust camshaft 5 on the cylinder heads of the banks 2R and 2L, respectively. This is a so-called DOHC V6 engine provided one by one. Here, the intake camshafts 4 open and close the intake valves (not shown) provided in the cylinder heads of the corresponding banks 2R and 2L, and the exhaust camshafts 5 correspond to the corresponding banks 2R and 2L. The exhaust valve (not shown) provided in each cylinder head is opened and closed.

  In the internal combustion engine 1 configured as above, the engine torque of the crankshaft 3 is transmitted to the pair of intake camshafts 4 parallel to each other via the control system 10, while the rotation of each intake camshaft 4 with respect to the crankshaft 3. The phase is adjusted by the system 10. Further, in the V6 engine that is generally used frequently, the ignition timing of each cylinder is equally spaced. Therefore, in the internal combustion engine 1 of the first embodiment, the valve timing of each intake valve in the same bank corresponds to the corresponding intake camshaft 4. With this cam structure, the crank angle is shifted by 240 degrees, and the valve timing of different banks is always shifted by 120 degrees by the control system 10. As a result, the alternating phase of the varying torque acting on each intake camshaft 4 due to the spring reaction force or the like of the intake valve is opposite in phase between the right bank 2R side and the left bank 2L side as illustrated in FIG. In addition, the shape is shifted so that the phase is inverted.

  In the internal combustion engine 1 of the present embodiment, the engine torque of the crankshaft 3 is transmitted to the pair of exhaust camshafts 5 parallel to each other via the control system 10, but the rotation of each exhaust camshaft 5 relative to the crankshaft 3 is performed. The phase is always constant regardless of the system 10.

(Basic configuration of control system)
As shown in FIG. 1, the control system 10 includes a pair of phase adjustment mechanisms 12 provided individually corresponding to the intake camshafts 4 of the banks 2R and 2L, an electromagnetic actuator 60 provided in common to the mechanisms 12, and energization. And a control circuit unit 80.

  The pair of phase adjusting mechanisms 12 are arranged coaxially with the corresponding intake camshafts 4. Each phase adjusting mechanism 12 has a drive side rotating body 14 connected to a sprocket portion 3 a of the crankshaft 3 via an individual intake chain 6. Engine torque is transmitted from the crankshaft 3 to the rotating body 14. It has come to be. Further, the driving side rotating body 14 of each phase adjusting mechanism 12 is connected to the sprocket portion 5 a of the corresponding exhaust camshaft 5 via an individual exhaust chain 7, and the engine torque is transmitted to the corresponding camshaft 5. It has come to be.

  Each phase adjusting mechanism 12 has a driven-side rotating body 20 that is directly connected to the corresponding intake camshaft 4, and can transmit torque with the corresponding camshaft 4. Each phase adjustment mechanism 12 has an input rotation shaft 40, and the driven-side rotator 20 is rotated relative to the drive-side rotator 14 in accordance with the rotation state of the shaft 40. Therefore, the rotation phase of each intake camshaft 4 is adjusted according to the input rotation shaft 40 of the corresponding phase adjustment mechanism 12.

  The electromagnetic actuator 60 is disposed between the pair of phase adjustment mechanisms 12, thereby reducing the size of the internal combustion engine 1 as a whole including the control system 10. The electromagnetic actuator 60 has an output rotation shaft 62 in parallel with each intake camshaft 4 coaxial with each phase adjustment mechanism 12. In the electromagnetic actuator 60, a magnetic holding torque that magnetically holds the output rotation shaft 62 acts on the shaft 62. Further, the electromagnetic actuator 60 generates output torque on the output rotation shaft 62 by energization, rotationally drives the shaft 62, and disappears the output torque by energization cut. In the present embodiment, the sprocket portion 62 c provided at one end of the output rotation shaft 62 is connected to the input rotation shaft 40 of each phase adjustment mechanism 12 via the individual control chain 70, and these input rotation shafts 40. Torque can be transmitted between the two.

  A part or all of the energization control circuit unit 80 is built in the electromagnetic actuator 60 and is electrically connected to the actuator 60. While the internal combustion engine is in operation, the energization control circuit unit 80 adjusts the rotation phase of each intake camshaft 4 by controlling the rotation of the output rotation shaft 62 by energizing the electromagnetic actuator 60, while the internal combustion engine is stopped. Thus, the power supply to the electromagnetic actuator 60 is cut off.

(Detailed configuration of phase adjustment mechanism)
The pair of phase adjustment mechanisms 12 have substantially the same configuration. Therefore, in the following, the detailed configuration of one phase adjustment mechanism 12 will be described, and the detailed configuration of the other phase adjustment mechanism 12 will be omitted.

  As shown in FIG. 3, the phase adjusting mechanism 12 is a differential gear type planetary mechanism having an input rotating shaft 40 and a planetary gear 50 in addition to the driving side rotating body 14 and the driven side rotating body 20.

  The drive side rotator 14 is formed in a hollow shape by screwing the sun gear 15 and the timing sprocket 16, and houses the other components 20, 40, 50 of the phase adjustment mechanism 12 therein.

  As shown in FIGS. 3 and 4, the sun gear 15 forms a drive-side internal gear portion 17 having a tip circle on the inner peripheral side of the root circle by a peripheral wall portion. Further, as shown in FIG. 3, the timing sprocket 16 has an intake sprocket portion 18 and an exhaust sprocket portion 19 formed coaxially by a peripheral wall portion. The intake sprocket portion 18 is connected to the crankshaft 3 by the intake chain 6 being spanned between the sprocket portion 3a (see FIG. 1) of the crankshaft 3. Further, the exhaust sprocket portion 19 is connected to the corresponding camshaft 5 by the exhaust chain 7 being spanned between the sprocket portion 5a (see FIG. 1) of the corresponding exhaust camshaft 5. As described above, when the engine torque of the crankshaft 3 is transmitted to the intake chain 6, the drive side rotating body 14 rotates in the same phase in conjunction with the crankshaft 3, and the corresponding exhaust camshaft 5 moves the exhaust chain 7. The engine torque is transmitted through the crankshaft 3 and rotated in the same phase. Here, the rotation direction of the drive side rotator 14 is set to the clockwise direction in FIGS.

  As shown in FIGS. 3 and 5, the driven side rotating body 20 is arranged concentrically on the inner peripheral side of the driving side rotating body 14, and has a driven side internal gear having a tooth tip circle on the inner peripheral side of the root circle. The portion 22 is formed by a peripheral wall portion. The driven rotating body 20 is coaxially connected to the corresponding intake camshaft 4 by screwing. As a result, the driven-side rotator 20 has the same phase in conjunction with the intake camshaft 4 in the connected state (hereinafter, the intake camshaft 4 connected to the driven-side rotator 20 is particularly referred to as “connected camshaft 4”). It is rotatable and is rotatable relative to the drive side rotator 14. Here, the rotation direction of the driven side rotator 20 is set in the clockwise direction of FIG. Further, in this embodiment, the relative rotation direction of the driven-side rotator 20 to the advance side with respect to the drive-side rotator 14 is the direction of the negative torque among the varying torques that alternate between positive and negative as shown in FIG. In other words, the relative rotational direction of the driven-side rotator 20 to the retard side with respect to the drive-side rotator 14 coincides with the positive torque direction shown in FIG.

  As shown in FIG. 3, the input rotating shaft 40 has a control sprocket portion 42 coaxial with the driving side rotating body 14 at one end. The control sprocket portion 42 is connected to the rotary shaft 62 by the control chain 70 being spanned between the sprocket portion 62 c of the output rotary shaft 62. Thereby, the input rotary shaft 40 can be driven to rotate in the same phase as the output rotary shaft 62 and can be rotated relative to the drive-side internal gear portion 17.

  As shown in FIGS. 3 to 5, the input rotation shaft 40 forms a planetary support portion 44 that is eccentric with respect to the drive-side rotator 14 by a peripheral wall portion opposite to the control sprocket portion 42. The planetary support portion 44 supports the planetary gear 50 via the bearing 45 so that the planetary movement is possible. Here, the planetary movement refers to a planetary movement in which the planetary gear 50 revolves around the eccentric center line of the planetary support portion 44 and revolves in the rotation direction of the input rotation shaft 40.

  The planetary gear 50 forms a drive-side external gear portion 52 and a driven-side external gear portion 54 having a tip circle on the outer peripheral side of the root circle. The drive side external gear portion 52 is disposed on the inner peripheral side of the drive side internal gear portion 17 and meshes with the internal gear portion 17. The driven-side external gear portion 54 is disposed on the inner peripheral side of the driven-side internal gear portion 22 and meshes with the internal gear portion 22.

  In this way, the phase adjusting mechanism 12 having the gears connected between the rotating bodies 14 and 20 transmits the variable torque (see FIG. 2) alternating between positive and negative from the connecting cam shaft 4 side to the output rotating shaft 62 while performing input rotation. The rotation phase of the connection cam shaft 4 is adjusted according to the rotation state of the output rotation shaft 62 that drives the shaft 40.

  Specifically, when the output rotating shaft 62 rotates the input rotating shaft 40 at the same speed as the driving side rotating body 14, the planetary gear 50 is rotated when the input rotating shaft 40 does not rotate relative to the driving side internal gear portion 17. It rotates with the rotating bodies 14 and 20 without planetary motion. Thereby, since the rotational phase of the connection cam shaft 4 does not change, the valve timing is maintained for each intake valve driven by the shaft 4.

  On the other hand, when the output rotation shaft 62 rotates the input rotation shaft 40 at a high speed with respect to the drive-side rotator 14, the planetary gear 50 is rotated when the input rotation shaft 40 rotates relatively to the advance side with respect to the drive-side internal gear portion 17. The planetary motion causes the driven-side rotator 20 to rotate relative to the drive-side rotator 14 toward the advance side. As a result, the rotational phase of the connection cam shaft 4 changes to the advance side, so that the valve timing is advanced for each intake valve driven by the shaft 4.

  On the other hand, when the output rotation shaft 62 rotates the input rotation shaft 40 at a low speed or reverse rotation with respect to the drive-side rotator 14, the input rotation shaft 40 rotates relatively to the retard side with respect to the drive-side internal gear portion 17. The planetary gear 50 moves in a planetary motion, and the driven-side rotator 20 rotates relative to the retard side with respect to the drive-side rotator 14. As a result, the rotational phase of the connecting cam shaft 4 changes to the retard side, so that the valve timing of each intake valve driven by the shaft 4 is retarded.

(Detailed configuration of electromagnetic actuator)
Hereinafter, the detailed configuration of the electromagnetic actuator 60 will be described. As shown in FIGS. 3 and 6, the electromagnetic actuator 60 is a brushless permanent magnet type synchronous electric motor, and includes a motor case 63, a bearing 64, a permanent magnet 65, and a motor stator 66 in addition to the output rotating shaft 62. Yes.

  The motor case 63 is fixed to a fixed node (for example, a chain case) of the internal combustion engine and is positioned between the phase adjustment mechanisms 12. The pair of bearings 64 is housed and fixed in the motor case 63, and rotatably supports the shaft main body 62a of the output rotating shaft 62 provided with the sprocket portion 62c. The rotor portion 62b of the output rotating shaft 62 is formed of a magnetic material in the shape of an annular plate protruding from the shaft main body 62a to the outer peripheral side, and a plurality of permanent magnets 65 are provided on the outer peripheral surface of the rotor portion 62b. It is mounted in the form of being arranged at equal intervals in the 62 rotation direction. Here, the permanent magnets 65 adjacent in the rotation direction form magnetic poles having opposite polarities on the outer peripheral side of the rotor portion 62b. The motor stator 66 is housed and fixed in the motor case 63, and is located concentrically on the outer peripheral side of the rotor portion 62b. In the motor stator 66, the plurality of cores 66 a are formed by laminating metal pieces, and are arranged at equal intervals in the rotation direction of the output rotation shaft 62. In the motor stator 66, the plurality of coils 66b are individually wound around the corresponding cores 66a.

  In such an electromagnetic actuator 60, the magnetic force of each permanent magnet 65 mounted on the output rotation shaft 62 acts on the motor stator 66 to magnetize each core 66a, so that cogging torque as magnetic holding torque is output to the output rotation shaft. 62 is acted upon. Further, in the electromagnetic actuator 60, each coil 66 b of the motor stator 66 is excited by energization from the energization control circuit unit 80 to apply a magnetic field to each permanent magnet 65, thereby rotating the output rotation shaft 62. Motor torque is generated as output torque. In this way, the energization control circuit unit 80 of the present embodiment that controls energization of the electromagnetic actuator 60 as an electric motor is configured by, for example, a control computer and an energization driver.

(Characteristic operation of control system)
Hereinafter, characteristic operations of the control system 10 will be described. As shown in FIG. 7, when the internal combustion engine 1 in the idling state is stopped upon receiving an ignition switch OFF command, the energization control circuit unit 80 detects the OFF command and performs stop control. Specifically, in the stop control, first, the rotation of the output rotating shaft 62 is controlled by energizing each coil 66b of the motor stator 66, so that the rotational phases of the connection cam shafts 4 connected to the respective phase adjusting mechanisms 12 are both set. The set phase Ph is held.

  Next, in the stop control, when the rotational speed of the internal combustion engine 1 becomes a threshold value Rth (for example, 200 rpm) or less as shown in FIG. 7, the energization to each coil 66b is cut off. As a result, when the internal combustion engine 1 is completely stopped, the output rotating shaft 62 is also completely stopped almost simultaneously, but the time from the energization cut to the complete stopping of the output rotating shaft 62 is very short (for example, about 0.1 second). . Therefore, the rotational phases of the connecting camshafts 4 both stop at a substantially constant phase Ps slightly retarded from the set phase Ph. Therefore, in the present embodiment, the set phase Ph is set so that the phase Ps becomes a start phase suitable for the next start of the internal combustion engine 1, more preferably a start phase that improves fuel consumption and environmental performance. Here, the phase Ps as the starting phase is an intermediate phase between the most retarded angle phase and the most advanced angle phase in the example of FIG. 7, but either the most retarded angle phase or the most advanced angle phase. It may be.

  In this manner, the fluctuation torque of the connection cam shaft 4 may be transmitted to the output rotation shaft 62 through the phase adjustment mechanism 12 in a state where the rotation phase of each connection cam shaft 4 reaches the phase Ps. At this time, in the output rotating shaft 62, as shown in FIG. 2, the fluctuation torques from the connecting cam shafts 4 of the banks 2R and 2L in the relationship of opposite phase and inversion phase cancel each other, so that these fluctuation torques Will be reduced to zero or close to it. Therefore, according to the cogging torque that acts as the magnetic holding torque on the output rotating shaft 62 in the energization cut state, the combined torque of the variable torque can be overcome even if the magnitude is small. Accordingly, the rotation controllability of the output rotation shaft 62 by energization during engine operation, and thus the controllability of the valve timing, while maintaining the output rotation shaft 62 by such cogging torque while sufficiently reducing the cogging torque that causes the deterioration. Thus, the phase Ps as the starting phase can be secured.

  In addition, in the present embodiment in which the phase adjusting mechanisms 12 connected to the individual connecting cam shafts 4 are connected to the common output rotating shaft 62, the output rotation is caused by the failure of the electromagnetic actuator 60 or the energization control circuit unit 80. Even if the rotation control of the shaft 62 is hindered, the rotational phase shift of each connecting cam shaft 4 does not substantially occur. Therefore, an effect of avoiding a situation where the internal combustion engine 1 becomes difficult to start due to a shift in the rotational phase of each connecting camshaft 4 can also be obtained.

  According to the first embodiment described above, both the startability of the internal combustion engine 1 and the controllability of the valve timing can be ensured, which can greatly contribute to the improvement of the fuel consumption and environmental performance of the internal combustion engine 1. In the first embodiment so far, the intake valve driven by each connecting cam shaft (intake cam shaft) 4 corresponds to the “valve valve” recited in the claims, and the energization control circuit unit 80 is patented. This corresponds to the “energization control means” recited in the claims.

(Second embodiment)
As shown in FIG. 8, the second embodiment of the present invention is a modification of the first embodiment. In the internal combustion engine 101 to which the control system 10 is applied in the second embodiment, four cylinders are formed in each of the right bank 102R and the left bank 102L that form approximately 90 degrees, and the cylinder heads of these banks 102R and 102L are provided. This is a so-called DOHC V8 engine in which one intake camshaft 4 and one exhaust camshaft 5 are provided. Here, in the V8 engine that is generally used frequently, the ignition timing of each cylinder is unequal, so in the internal combustion engine 101 of the second embodiment, the valve timing of each intake valve in the same bank corresponds to the corresponding intake cam. The cam structure of the shaft 4 is shifted from each other, and the valve timing of different banks is always shifted by the control system 10. As a result, the alternating phase of the fluctuating torque acting on each intake camshaft 4 is shifted so as to be in opposite phases on the right bank 2R side and the left bank 2L side as illustrated in FIG. Yes.

  Even in the control system 10 of the second embodiment, under the state where the rotation phase of each connection camshaft 4 reaches the phase Ps by the stop control of the energization control circuit unit 80, the fluctuation torque of the connection camshaft 4 is changed to each level. It may be transmitted to the output rotation shaft 62 through the phase adjustment mechanism 12. At this time, in the output rotating shaft 62, as shown in FIG. 9, the fluctuation torques of the connecting camshafts 4 having the opposite phases cancel each other, so that the combined torque of these fluctuation torques is about 1/3 or less. Will be reduced. Therefore, while reducing the cogging torque, which becomes a cause of deterioration in controllability of the valve timing, as much as possible, the output rotating shaft 62 can be held by such cogging torque to ensure the phase Ps as the starting phase. .

(Other embodiments)
Although a plurality of embodiments of the present invention have been described above, the present invention is not construed as being limited to these embodiments, and can be applied to various embodiments without departing from the scope of the present invention. .

  The internal combustion engine to which the control system 10 is applied is not limited to the above-mentioned DOHC type V-type engines 1 and 101 as long as the rotation phase of a plurality of camshafts can be adjusted using a common electromagnetic actuator 60. There may be. In addition to the above-described system for controlling the valve timing of the intake valve, the control system 10 controls the valve timing of the exhaust valve as the “valve”, and the valve timing of both the intake valve and the exhaust valve. It may be a controlling system.

  As the electromagnetic actuator 60 of the control system 10, other than the brushless permanent magnet type synchronous electric motor described above is adopted as long as the output torque can be generated by energizing the output rotating shaft 62 on which the magnetic holding torque acts. May be. For example, an electric brake or the like having a configuration in which a braking torque is applied to the output rotating shaft 62 as an output torque and a magnetic holding torque by a permanent magnet acts on the shaft 62 may be employed as the electromagnetic actuator 60. Furthermore, the location of the electromagnetic actuator 60 can be appropriately set according to the specifications of the internal combustion engines 1 and 101 and the like.

  The phase adjustment mechanism 12 combined with the electromagnetic actuator 60 in the control system 10 is capable of adjusting the rotational phase of the connecting cam shaft in accordance with the rotational state of the shaft 62 while transmitting the varying torque to the output rotational shaft 62. If there is any other than the above-described differential gear type planetary mechanism, it may be adopted. Further, as a connection form between the phase adjusting mechanism 12 and the output rotating shaft 62, for example, a connection form using a belt or a connection form using a gear mechanism may be employed in addition to the connection form using the chain 70 described above. . Further, the phase adjusting mechanism 12 may be connected to the common output rotating shaft 62 by providing the same number as the number of cam shafts whose rotational phases are to be adjusted.

It is a front view showing typically an example which applied a valve timing control system to an internal-combustion engine as a first embodiment of the present invention. FIG. 2 is a schematic diagram for explaining a variable torque acting on a pair of intake camshafts in FIG. 1 and a combined torque of the variable torques on the output rotation shaft in FIG. 1. It is sectional drawing which shows the detailed structure of the phase adjustment mechanism and electromagnetic actuator of FIG. It is the IV-IV sectional view taken on the line of FIG. It is the VV sectional view taken on the line of FIG. It is the VI-VI sectional view taken on the line of FIG. It is a schematic diagram for demonstrating the characteristic action | operation of the valve timing control system of FIG. It is a front view which shows typically another example which applied the valve timing control system to the internal combustion engine as 2nd embodiment of this invention. FIG. 9 is a schematic diagram for explaining a variable torque acting on each of the pair of intake camshafts of FIG. 8 and a combined torque of the variable torques on the output rotation shaft of FIG. 8.

Explanation of symbols

1,101 Internal combustion engine, 2R, 102R right bank, 2L, 102L left bank, 3 crankshaft, 3a, 5a, 62c sprocket part, 4 intake camshaft / connection camshaft, 5 exhaust camshaft, 6 intake chain, 7 exhaust Chain, 10 Valve timing control system, 14 Drive side rotator, 16 Timing sprocket, 18 Intake sprocket part, 19 Exhaust sprocket part, 20 Driven side rotator, 40 Input rotating shaft, 42 Control sprocket part, 50 Planetary gear, 60 Electromagnetic Actuator, 62 Output rotating shaft, 63 Motor case, 65 Permanent magnet, 66 Motor stator, 66a Core, 66b Coil, 70 Control chain, 80 Energization control circuit (energization control means)

Claims (5)

A valve timing control system for controlling valve timing of a valve that is driven to open and close by each camshaft by torque transmission from a crankshaft in an internal combustion engine in which fluctuating torques of alternating phases act on a plurality of camshafts. There,
An electromagnetic actuator having an output rotating shaft on which a magnetic holding torque acts, and generating an output torque on the output rotating shaft by energization;
Energization control means for controlling rotation of the output rotation shaft by energization of the electromagnetic actuator, and cutting off energization to the electromagnetic actuator when the internal combustion engine is stopped;
The connecting cam for the crankshaft according to the rotation state of the output rotating shaft while transmitting the variable torque from the connecting camshaft as the individually connected camshaft to the commonly connected output rotating shaft A plurality of phase adjustment mechanisms for adjusting the rotational phase of the shaft;
A valve timing control system comprising:   The variable torque transmitted from the connection cam shaft to the output rotation shaft through each of the pair of phase adjustment mechanisms in the pair of cam shafts is in opposite phase to each other. Valve timing control system.   The said phase adjustment mechanism transmits the said fluctuation | variation torque to the said output rotating shaft from the said connection cam shaft among a pair of said cam shafts with which the said V-type internal combustion engine is provided. Valve timing control system.   The electromagnetic actuator is an electric motor that generates a motor torque as the output torque on the output rotating shaft on which a cogging torque as the magnetic holding torque acts. The valve timing control system according to item.   5. The electromagnetic actuator according to claim 1, wherein the electromagnetic actuator is disposed between a pair of the phase adjustment mechanisms that are coaxially connected to the connection cam shaft among the pair of cam shafts parallel to each other. The valve timing control system according to claim 1.

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