KR20070022827A - Valve gear for multi-cylinder internal combustion engine - Google Patents

Abstract

The valve drive device 10 which is provided to each cylinder 2 and converts the rotational motion output from the valve drive source into the linear motion through the cam mechanism 13 which drives the valve 3 of each cylinder through the linear motion. As the valve drive device, there are provided electric motors (11, 12) shared as a valve driving source of a group of cylinders including a plurality of cylinders in which the valve opening period of the valve does not overlap; And movement transmission mechanisms 14 and 15 for transmitting the rotational movements of the electric motors 11 and 12 to the cams 16 of the respective cam mechanisms 13 of the cylinder group.

Valve drive

Description

VALVE GEAR FOR MULTI-CYLINDER INTERNAL COMBUSTION ENGINE}

The present invention relates to a valve drive device used in a multi-cylinder internal combustion engine and driving to open and close the valve of each cylinder of the internal combustion engine.

For example, Japanese Patent Application Laid-Open No. 1989-16964 discloses a form of a valve drive device in which at least one of an intake valve and an exhaust valve is driven by a stepper motor. For example, Japanese Utility Model Laid-Open Publication No. 1990-27123 discloses, for each valve, another type of valve drive device including a cam mechanism for converting rotational motion of an electric motor and a linear motion of the valve to each valve. have. In addition, JP 2002-500311 A is related to the present invention as a prior cited document.

When the electric motor is controlled to change the operating characteristics of the valve in the case of sharing the electric motor as a valve driving source of a plurality of cylinders of a multi-cylinder internal combustion engine, the valve opening period of the valve is changed as the valve opening period is changed. The motor may affect the operating characteristics of other valves. Thus, the flexibility of controlling the operating characteristics of the valve is limited. On the other hand, when an electric motor is used for each valve, the operating characteristics of the valve can be flexibly changed for each valve. However, as the number of electric motors increases, the valve drive device becomes larger and the constraints on mounting the valve drive device on the vehicle become larger.

It is an object of the present invention to provide a miniaturized valve drive device capable of flexibly controlling the operating characteristics of a valve.

In order to achieve the above object, the valve drive device for a multi-cylinder internal combustion engine according to an aspect of the present invention, by converting the rotary motion output from the valve drive source to a linear motion through the motion conversion device provided in each cylinder, respectively An electric motor that drives a valve of a cylinder of the cylinder and which is shared as a valve driving source in a cylinder group including a plurality of cylinders in which the valve opening period of the valve does not overlap.

According to the valve driving apparatus, since one electric motor is shared as a valve driving source in a plurality of cylinders, the apparatus is miniaturized and the constraint of mounting the valve driving apparatus is alleviated as compared with the case where the electric motor is provided in each cylinder. Further, in the cylinder group sharing the electric motor, the valve opening period does not overlap, and thus there is a period in which all the valves are sealed between the valve opening periods of the valves. Therefore, when the operating characteristics of the valves (either intake valves or exhaust valves) of the cylinders of the cylinder group are changed by changing the rotational speed and the direction of the electric motor, the time when the previously opened valve is closed and the valve which is opened next The operating characteristics of the previously opened valve over the operating characteristics of the next open valve by further changing the rotation of the electric motor to compensate for the previous change in the period between the time it is opened (the period during which all valves are closed). The impact of the change is offset. For example, if the electric motor is accelerated during the valve opening period of the valve to reduce the angle of action of the valve, the position of the starting point of the opening of the next valve is reduced by decelerating the electric motor corresponding to the accelerated amount before the next valve opens. It does not change. By controlling the electric motor, a change similar to that of the previous valve or a unique change in the operating angle is provided to the next valve. In addition, when the operating characteristics of the valve are changed by combining the stop and reverse rotation of the electric motor, the control of the rotation of the electric motor to cancel the previous change before the next valve is opened, respectively, without affecting the operation of other valves. The operation of the valve is controlled. As such, the operating characteristics of each cylinder can be flexibly controlled. It should be noted that the change in rotational speed described herein includes the concept of controlling the rotational speed to zero, ie stopping the rotation of the electric motor.

In an aspect of the valve drive device of the present invention, the valve drive device may further include a motion transmission mechanism for transmitting the rotational motion of the electric motor to the rotating body of each motion conversion device of the cylinder group. Moreover, in the aspect of the valve drive apparatus of this invention, the torque reduction mechanism which reduces the drive torque which arises when driving each valve of a cylinder group can be shared by a cylinder group. When the electric motor is shared with the cylinders of the cylinder group, each torque represented by the rotational resistance of the electric motor when the valve of each cylinder is driven can all be reduced by the common torque reducing mechanism. In this way, the common use of the torque reduction mechanism prevents the valve drive device from becoming large and alleviates the constraint on mounting the valve drive device in the vehicle.

The exercise transmission mechanism may be provided with a transmission axis connecting the rotation bodies of the motion transfer devices of the cylinder group to each other, and the electric motor may be connected to the exercise transmission axis to transmit the rotational motion to the exercise transmission axis. According to this configuration, rotational motion can be uniformly transmitted to each motion transmitting device of the plurality of cylinders by connecting an electric motor to the motion transmitting shaft.

In the present invention, the internal combustion engine may be constituted by an equally spaced ignition in-line four-cylinder four-stroke cycle internal combustion engine in which the ignition interval between the outer cylinder pairs is set to 360 ° crank angle in the ignition order of the cylinders. In this case, the first electric motor common to the motion switching device of the first group cylinder composed of the outer cylinder pair as the electric motor and the second electric motor shared to the motion switching device of the second group cylinder composed of the inner cylinder pair are used. Each of the second group cylinders to provide a rotational motion of the first and second motion transfer mechanisms, the second motion motor providing and transmitting the rotational motion of the first electric motor to the rotors of the respective motion conversion devices of the first group cylinders as the motion transfer mechanism. A valve drive device according to an aspect of the present invention is achieved by providing a second motion transfer mechanism for transmitting to a rotating body of the motion switching device. In this configuration, "four stroke cycle" means an operation in which four strokes of intake, compression, explosion and exhaust occur continuously while the crank rotates twice. Even though the cycle can be switched to a two-stroke cycle in which four strokes occur during one revolution of the crankshaft through control of the operating characteristics of the valve, the cycle is still four strokes, including when four-cycle cycle operation is performed. Are classified into cycles.

In addition to the above aspect, the first motion transmission mechanism may be provided with a first motion transmission shaft connecting the rotation bodies of the respective motion conversion devices of the first group cylinder, and the second motion transmission mechanism may each be provided with each of the second group cylinders. A second motion transmission shaft for connecting the rotating bodies of the motion conversion device of the may be installed. The second motion transmission axis may be coaxially located outside of the first motion transmission axis, the first electric motor may be connected to the first motion transmission axis to transmit rotational motion to the first motion transmission axis, and the second electric motor may be And may be coupled to the second exercise transmission axis to transmit rotational motion to the second exercise transmission axis. According to this configuration, even if the cylinders of the first group cylinder are separated from each other by the second group cylinder, the rotational motion of the first electric motor can be transmitted to the motion switching device of each cylinder of the first group cylinder. Rotational motion can also be transmitted to the second group cylinder by connecting an electric motor around the second group cylinder.

In an aspect of the present invention, the internal combustion engine may consist of an equally spaced ignition six-cylinder four-stroke cycle internal combustion engine. In this case, the cylinder group may be composed of cylinders in which the ignition timing between each cylinder is set to 360 ° in the crank angle in the ignition order of the cylinders, and an electric motor and a transmission mechanism may be provided to each cylinder. . According to this configuration, the present invention can be achieved by providing a sufficient closing time for all valves between the opening times of each valve of one cylinder group. However, at some operating angles of the valve, two or more cylinders with an ignition interval of less than 360 degrees crank angle may be included in one cylinder group. The meaning of the four-stroke cycle is the same as above.

In the aspect of the valve drive device of the present invention, for example, a cam mechanism can be used as the motion switching device, and the cam of the cam mechanism can be treated as a rotating body of the motion switching device. That is, the valve drive device can be constituted by the operation of the cam provided to each cylinder which operates the valve and whose valve opening period does not overlap each other by the electric motor.

In an aspect of the present invention, the valve drive device may further include a control device for controlling the operating characteristics of each valve of the cylinder group by changing one or more rotational speeds and rotational directions of the electric motor. When an electric motor is used as a valve driving source for a valve of each of a plurality of cylinder groups composed of a plurality of cylinders in which the valve opening period does not overlap, the control device may be changed by changing one or more rotation speeds or rotation directions of each electric motor. Each valve of the cylinder group can be controlled.

In addition to the above aspect, the valve drive device may include a cam mechanism for converting the rotational motion output from the electric motor into the linear motion of the valve, wherein the control device drives the valve when the lift amount of each valve is maximized. The electric motor can be controlled so that the cam of the cam mechanism continues to rotate in the same direction while varying the rotational speed such that the rotational speed of the cam is maximum or minimum. In this case, the operating angle of the valve can be changed by changing the rotational speed. In addition, in the change in the lift amount of the valve obtained by changing the operating angle, the adjustment range of the operating angle can be maximized by controlling the change in the rotation speed so as to maximize or minimize the rotation speed when the lift amount becomes maximum. When an electric motor is used for each of the plurality of cylinder groups, preferably, the control device controls one of the electric motors as above.

Further, in the above aspect, the valve drive device may include a cam mechanism for converting the rotational motion output from the electric motor into the linear motion of the valve, each cylinder group may be composed of two cylinders, the electric motor Is reversed while changing the swing amount within a range between the position where the maximum lift amount is given by the cam of the cam mechanism of the cylinder of the cylinder group and the position where the maximum lift amount is given by the cam of the cam mechanism of another cylinder of the cylinder group. The control device can drive an electric motor to oscillate in two directions. According to the above configuration, through the swinging of the cam, the peak lift amount of the valve of each cylinder can be controlled to be equal to or less than the maximum lift amount given by the cam. The peak lift amount can be continuously changed by changing the swing amount of the electric motor. Further, when a plurality of electric motors are used for each of the plurality of cylinder groups and each of the cylinder groups has two cylinders, preferably, the control device controls each electric motor as described above.

In the above aspect, the control device can further change the rotational speed of the electric motor during swinging. By varying the rotational speed during oscillation the operating angle of the valve can be changed continuously. Thus, the intake valve is provided with an operating characteristic of reducing the intake amount by reducing the lift amount and the operating angle in the control of the intake valve, and thus the pumping loss can be reduced by opening the intake throttle such as the throttle valve. When a plurality of electric motors are used in a plurality of cylinder groups, the control device can further change the rotational speed of the electric motor upon swinging.

Further, in the swing control, the control device can control the electric motor to alternately use both sides of the head of the nose portion of the cam of the cylinder group during valve driving. In the swing control, the valve of each cylinder can be opened and closed using only one side of the head of the cam nose portion, but it tends to be biased toward the side where lubrication or wear is used. Alternatively, when both sides are used alternately, lubrication or bias of wear can be prevented. In addition, "alternatively" refers to driving the valve by alternately using both sides in a predetermined period, and is not limited to the case where both sides are alternately used every time the cam is opened and closed. The change in duration depends on variables such as swing time and frequency. When a plurality of electric motors are used for a plurality of cylinder groups, the control device can control the electric motors so that the cam of each cylinder group is used as above.

In an aspect of the valve drive device of the present invention, the control device includes two directions in which the electric motor is reversed so that in the reduction cylinder operation of the internal combustion engine, the valve of one cylinder of the cylinder group is opened and closed and the valve of the other cylinder of the same cylinder group is closed. Can be shaken with Through oscillation of the electric motor within this range, reduction cylinder operation is achieved by burning in one cylinder and stopping combustion in the other cylinder. In this case, since no mechanical valve stopper is required, the valve drive device can be simplified.

Further, in the configuration in which the electric motor is used as the valve driving source in each of the plurality of cylinder groups, the control device may stop a part of the electric motor in a position where all the valves driven by the respective motors are closed in the reduction cylinder operation of the internal combustion engine. Can be. Since the valve opening period of each cylinder does not overlap in the same cylinder group, combustion can be stopped in all cylinders of the same cylinder group by stopping the electric motor at an appropriate position within the range in which the valves of all cylinders are sealed. Reduction cylinder operation is achieved by controlling a portion of the electric motor as above while controlling the other electric motor to open and close each valve.

In addition to the above aspect, the control device may control each electric motor such that in the reduction cylinder operation of the internal combustion engine, the number of cylinders in which the valve is closed is less than the total number of cylinders. As described above in connection with the above configuration, the combustion in one or more cylinders in the same cylinder group can be stopped by swinging the electric motor in two opposite directions or by stopping the electric motor. By adjusting the combustion stop control and varying the number of non-combustion cylinders within the total number of cylinders, the operating state can be flexibly controlled in reduced cylinder operation of the internal combustion engine.

In addition to the above aspects, the control device is adapted to reduce the number of cylinders in which the valve is closed in the reduction cylinder operation of the internal combustion engine to less than the total number of cylinders, and to change the amount of one or more lifts and operating angles of the cylinders in the cylinder in which the valve is opened and closed. You can control the electric motor. In this case, by changing the number of non-combustion cylinders less than the total number of cylinders and the lift amount or operating angle in the combustion cylinder, the intake efficiency or exhaust efficiency in the cylinder is changed and the operating state of the internal combustion engine can be flexibly controlled. For example, pumping loss and engine braking force are constantly controlled by varying the lift amount of the intake valve and the operating angle of the valve.

1 is a perspective view showing an embodiment of a valve drive device according to the present invention.

Fig. 2A is a diagram showing the relationship between the crank angle and the valve opening period of each cylinder of the internal combustion engine to which the present invention is applied.

FIG. 2B is a diagram showing a relationship between the crank angle and the valve opening time in the first group cylinder in which the valve opening period does not overlap. FIG.

2C is a diagram showing a relationship between the crank angle and the valve opening time in the second group cylinder in which the valve opening period does not overlap.

3 is an exploded view of the valve drive device of FIG. 1.

4 is a cross-sectional view of the valve drive device of FIG. 1.

It is a figure which shows the cam of the same cylinder group in an overlapping system.

6 is a diagram illustrating a torque reduction mechanism.

7 is a diagram showing an antiphase cam of the torque reducing mechanism.

FIG. 8 is a diagram showing a change in operating characteristics that can be realized by the valve drive device of FIG. 1.

Fig. 9 is a diagram showing the relationship between the valve spring torque by the valve spring and the antiphase torque by the torque reducing mechanism with respect to the crank angle.

10 is a diagram showing an embodiment in which an engine control unit as an electric motor control device is provided in the valve drive device of FIG. 1.

FIG. 11 is a diagram showing the relationship between the cam speed and the lift amount of the intake valve with respect to the crank angle when the electric motor is controlled to reduce the operating angle of the intake valve.

Fig. 12 is a diagram showing an embodiment in which the phase of the cam speed change is changed so as to rotate the cam at the maximum speed at the position where the lift amount of the intake valve is maximum.

Fig. 13 is a diagram showing an embodiment in which the phase of the cam speed is changed to the opposite phase.

14A to 14C are views showing an embodiment in which the intake valves of the two cylinders are opened and closed by swinging the cam.

FIG. 15 is a diagram showing the relationship between the cam angle, the cam speed, and the lift amount of the intake valve with respect to the crank angle when the intake valves of the two cylinders are opened and closed by swinging the cam.

FIG. 16 is a view showing a relationship between a cam angle, a cam speed, and a lift amount of an intake valve when the intake valve of one cylinder is opened and closed and the intake valve of the other cylinder is stopped by opening and closing of the cam; to be.

17A-17C illustrate an embodiment of a combination of a cylinder in operation and a cylinder that is stopped when the intake valve of one cylinder is stopped and the intake valve of another cylinder is opened and closed.

FIG. 18 is a view showing an embodiment in which a valve drive device is applied to a V-type six cylinder internal combustion engine.

FIG. 19A is a diagram showing the relationship of the lift amount of each valve to the crank angle when the standard operating angle is set to 240 ° CA in the internal combustion engine of FIG. 18. FIG.

FIG. 19B is a diagram showing the relationship of the lift amount of each valve to the crank angle when the standard operating angle is set to 180 ° CA in the internal combustion engine of FIG.

20 is a view showing another embodiment in which the valve drive device is applied to a V-shaped six-cylinder internal combustion engine according to the present invention.

Fig. 21 is a diagram showing an example of cylinder arrangement and cylinder numbering of a series 6 cylinder internal combustion engine.

FIG. 22A shows the relationship of the lift amount of each valve to the crank angle when the standard operating angle is set to 240 ° CA in the internal combustion engine of FIG. 20. FIG.

FIG. 22B shows the relationship of the lift amount of each valve to the crank angle when the standard operating angle is set to 180 ° CA in the internal combustion engine of FIG. 20.

1 shows an embodiment in which the valve drive is applied to a reciprocating four-stroke cycle internal combustion engine. The internal combustion engine 1A is an in-line four-cylinder engine having four cylinders 2 arranged in a row. In Fig. 1, cylinders # 1 to # 4 are numbered from one end to the other end of cylinders arranged in series to distinguish each cylinder 2 from other cylinders. Typically, in a four-stroke cycle four-cylinder internal combustion engine 1A, the ignition spacing between the outer # 1 cylinder and # 4 cylinder 2 pair is 360 ° .CA (hereinafter '° .CA' is the crank). Angle), and the ignition timing of the inner # 2 cylinder and # 3 cylinder 2 pairs is delayed from the ignition timing of the # 1 cylinder 2 to 180 ° CA and 540 ° CA, respectively. Thus, equal intervals of ignition are realized at intervals of 180 ° CA. It should be noted that the order of the ignition timing between the # 2 cylinder and the # 3 cylinder (2) can be changed freely. Hereinafter, it is assumed that the ignition timing of the # 3 cylinder 2 is in front of the ignition timing of the # 2 cylinder 2. Therefore, the ignition order of the cylinder 2 of the internal combustion engine 1A is set to # 1 → # 3 → # 4 → # 2.

Each cylinder 2 is provided with two intake valves 3. Here, the exhaust valve is not shown. The intake valve 3 is opened and closed by the valve drive device 10. As is well known in the art, in the intake valve 3, a stem 3a passing through a valve stem guide (not shown) of the cylinder head is capable of reciprocating in the axial direction of the stem 3a of the intake valve. Is provided. As shown in FIG. 4, the valve lifter 4 is fixed to the upper end of the intake valve 3 integrally and reciprocally. A valve spring 5 is mounted between the valve lifter 4 and the cylinder head. The intake valve 3 receives a repulsion force against the compression of the valve spring 5 in the direction in which the valve face 3b is in close contact with the valve seat of the intake port (the direction in which the valve is sealed). The valve drive device 10 drives the intake valve 3 in the direction of opening the valve with respect to the force of the valve spring.

2A shows the relationship between the crank angle and the lift amount of the intake valve 3 of each cylinder 2 (the lift amount is the displacement in the direction in which the valve opens in the closed position). The operating angle of each intake valve 3 (acting angle refers to the valve opening period in relation to the crank angle) is appropriately adjusted in accordance with the specifications of the internal combustion engine 1A. In addition, in the valve drive device provided with the variable valve drive mechanism, the operating angle changes according to the operating state of the internal combustion engine 1A. Typically, the operating angle of the intake valve 3 is set to 240 ° CA. In this setting of the operating angle, as shown in FIG. 2B, the valve opening periods of the intake valves do not overlap each other between the outer # 1 cylinder and the # 4 cylinder pair, and as shown in FIG. 2C, the inner # Between the two-cylinder and # 3 cylinder pairs, the valve opening periods of the intake valves do not overlap each other. Thus, as shown in Fig. 1, in the valve drive device 10 of the present embodiment, the cylinder is a second group consisting of a first group cylinder composed of a pair of outer cylinders 2 and an inner cylinder 2 pair. Are classified as cylinders. The first electric motor 11 and the second electric motor 12 are individually provided to each cylinder group as valve driving circles.

3 and 4 show the valve drive device 10 in detail. As shown in these figures, the valve drive device 10 includes each cam mechanism 13 serving as the motion switching device provided in each of the intake valves 3 as well as the electric motors 11 and 12; A first motion transmission mechanism and a second motion transmission mechanism 14, 15 for transmitting rotation of the electric motors 11, 12 to the cam mechanism 13 of each cylinder group corresponding to the motor. The cam mechanisms 13 all have the same configuration. The cam mechanism 13 has a cam 16 which is a rotating body and pushes the valve lifter 4 provided at the upper end of the intake valve 3 down using the cam 16 to push the intake valve 3 in the valve opening direction. Drive. In other words, the valve lifter 4 serves as a follower of the cam 16. As shown in FIG. 5, the profile of the cam 16 is set in a well known form provided with a nose portion 16b which partially protrudes from the base circle 16a. The valve lifter 4 is pushed downward by the nose portion 16b.

The first motion transmission mechanism 14 rotates the cam shaft 17 (first transmission shaft) and the electric motor 11 that connect the respective cams 16 of the outer # 1 cylinder and the # 4 cylinder to each other. And a reducer 18 to transmit to 17. The reducer 18 is configured to rotate and engage with the motor gear 19 and the motor gear 19 fixed to the output shaft 11a of the electric motor 11 and fixed to one end of the cam shaft 17. A driven gear 20. The cam shaft 17 has an interconnection structure in which the first shaft member 21 for driving the cam 16 of the # 1 cylinder and the second shaft member 22 for driving the cam 16 of the # 4 cylinder engage. Have The shaft connecting portion 23 is formed coaxially and integrally with the first shaft member 21, and the shaft connecting portion 23 runs over the # 2 cylinder and the # 3 cylinder and leads to the # 4 cylinder. Both shaft members 21 and 22 are connected to the same axis by fixing the shaft connection part 24 of the one end of the shaft connection part 23 to the axial connection hole 25 of the 2nd shaft member 22 on the same axis. Rotation stop means such as a spline is formed between the shaft connection portion 24 and the shaft connection hole 25. Thus, the first shaft member and the second shaft member 21, 22 are connected to rotate integrally. The shaft connecting portion 23 is smaller in diameter than the first shaft member and the second shaft member 21, 22. Although the cam 16 is integrally formed with the first shaft member and the second shaft member 21, 22, the cam 16 can be formed as a separate component from the shaft member 21, 22 and has a compression fitting or It can be fixed to the shaft members 21, 22 by fitting means such as a column fitting.

On the other hand, the second transmission mechanism 15 cams the rotation of the cam shaft 30 (second transmission shaft) and the electric motor 12 which connect the respective cams 16 of the inner # 2 cylinder and the # 3 cylinder to each other. A reducer 31 that transmits to the shaft 30. The reducer 31 rotates integrally with the motor gear 32 fixed to the output shaft 12a of the electric motor 12, the intermediate gear 33 that meshes with the motor gear 32, and the intermediate gear 33. And a driven gear 34 adapted to engage and fixed to the middle of the camshaft 30. The cam shaft 30 is configured in the form of a tubular shaft having a through hole 30a extending in the axial direction, and the cam 16 is integrally formed on the outer circumference of the cam shaft. The shaft connecting portion 23 of the cam shaft 17 is rotatably inserted into the through hole 30a of the cam shaft 30. Thus, the cam shaft 30 is disposed rotatably and coaxially around the outer circumference of the cam shaft 17. Further, the diameter of the cam shaft 30 is the same as the diameter of the first shaft member and the second shaft members 21 and 22 of the cam shaft 17. The cam 16 may be formed as a separate part from the cam shaft 30 and may be fixed to the cam shaft 30 by fitting means such as a compression fitting or a thermal fitting. The driven gear 34 is formed in the same way.

The cam 16 of one cylinder of # 1 or # 3 of the same cylinder group and the cam 16 of another cylinder of # 4 or # 2 of the other cylinder group are the head 16c of the cam nose part 16b. Are respectively connected to the camshafts 17 or 30 so that are positioned at 180 ° with respect to each other in the circumferential direction. Since the valve opening period of the intake valve 3 is replaced by 360 ° CA between these two cylinders, the cam 16 is configured in this way. Thus, as clearly shown in Fig. 5, a region X in which the nose portions 16b of the cams 16 do not overlap with each other appears in the circumferential direction of each cam axis 17, 30. It should be noted that the diameter of the base circle 16a is set so that a proper gap (valve gap) is made between the valve lifter 4 and the cam 16. In addition, the cam mechanism 13 can be provided in the crankcase, and the linear motion obtained in the cam mechanism is transmitted to the intake valve 3 through a motion transfer component such as a push rod. The internal combustion engine is not limited to the OHC type but may be an OHV type.

Each of the exercise transmission mechanisms 14 and 15 is provided with a torque reducing mechanism 40. As shown in detail in FIG. 6, the torque reduction mechanism 40 includes an antiphase cam 41 and a torque portion unit 42 that applies a frictional load to the outer circumference of the antiphase cam 41. It should be noted that the torque reducing mechanism 40 for the # 2 and # 3 cylinders is shown in FIG. The torque reduction mechanisms 40 for the # 1 cylinder and the # 4 cylinder also have the same configuration. The antiphase cam 41 is fixed so as to rotate integrally with one end of the second shaft member 22 of the cam shaft 17 and one end of the cam shaft 30. The antiphase cam 41 can be integrally formed on the shafts 17, 30. In addition, the antiphase cam 41 may be formed as a separate component and may be fixed to the shafts 17 and 30 by fitting means such as compression fittings or thermal fittings. The outer circumferential surface of the antiphase cam 41 is composed of a cam surface. As shown in Fig. 7, the profile of the cam surface is configured to have a pair of grooves 41b in a part of the base circle 41a. The groove 41b is provided so that the bottom 41c of the groove 41b is separated from each other by 180 ° in the circumferential direction.

Returning to FIG. 6, the torque part unit 42 is a lifter 43 arrange | positioned so that it may face the outer periphery of the antiphase cam 41, the retainer 44 arrange | positioned outside the lifter 43, and the lifter 43; It is mounted between the retainers 44 and includes a coil spring 45 that pushes the lifter 43 toward the antiphase cam 41. The roller 46 is rotatably fixed to one end of the lifter 43. The roller 46 is pressed to the outer circumference of the antiphase cam 41 by the repulsive force of the coil spring 45.

The lifter 43 corresponding to the antiphase cam 41 of the camshaft 17 is brought into contact with the bottom 41c of one of the grooves 41b provided in the antiphase cam 41. The head 16c of the nose portion 16b of the # 1 cylinder cam 16 fixed to the cam shaft 17 is in contact with the valve lifter 4 for the # 1 cylinder, and the roller 46 has another groove 41b. Head 16c of the nose portion 16b of the # 4 cylinder cam 16 fixed to the shaft 17 when in contact with the bottom 41c of the It is located in the circumferential direction of the cam shaft 17 so as to contact the bottom 41c of the groove 41b. In addition, the lifter 43 corresponding to the antiphase cam 41 of the shaft 30 causes the roller 46 to contact the bottom 41c of one of the grooves 41b provided in the antiphase cam 41. When the head 16c of the nose 16b of the # 3 cylinder cam 16 fixed to the shaft 30 is in contact with the valve lifter 4 for the # 3 cylinder, and the roller 46 has another groove 41b. The other groove provided with the head 16c of the nose portion 16b of the # 2 cylinder cam 16 fixed to the shaft 30 when it comes into contact with the bottom 41c of the cylinder is provided on the valve lifter 4 for # 2 cylinder. It is located in the circumferential direction of the cam shaft 30 so as to contact the bottom 41c of the 41b.

According to the valve drive device 10 configured as described above, the camshaft is driven by the electric motors 11 and 12 so as to continue to rotate in one direction at a speed half of the rotational speed of the crankshaft of the internal combustion engine 1A (hereinafter referred to as a standard speed). By driving the 17 and 30, the intake valve 3 is opened and closed simultaneously with the rotation of the crankshaft. This operation is similar to that of a typical mechanical valve drive that drives the valve with the power of the crankshaft.

Further, according to the valve drive device 10, as shown in items A to G of FIG. 8, the rotational speeds of the cam shafts 17 and 30 by the electric motors 11 and 12 are relative to the standard speed. By changing, the operating characteristic of the intake valve 3 changes in various ways in accordance with the change in the correlation between the crank angle and the phase of the cam 16. In Fig. 8, the solid lift means the operating characteristics of the intake valve 3 when the cam shafts 17 and 30 continue to rotate at the standard speed, and the lift lift in the imaginary line denotes a motor ( 11 and 12 show the changed operating characteristics of the intake valve 3 realized through the speed control. The transverse and longitudinal axes of the lift shape represent the crank angle and the lift amount, respectively.

First, the change in the operating characteristics shown in item A of FIG. 8 changes the rotation of the cam shafts 17 and 30 so that the correlation between the crank angle and the phase of the cam 16 changes while the intake valve 3 is closed. It is realized by accelerating or decelerating about its standard speed. When the rotation of the camshafts 17, 30 is accelerated or decelerated relative to its standard speed while the intake valve 3 is open, the operating angle changes as shown in item C of FIG. 8.

Item B of FIG. 8 shows that the lift of the intake valve 3 is less than the maximum lift amount, that is, the lift amount of the intake valve 3 when the head 16c of the nose portion 16b contacts the valve lifter 4. An example is shown in which the amount is limited. By stopping the electric motors 11 and 12 while the cam 16 opens the intake valve 3 and then rotating the electric motor in the opposite direction, such a change in lift amount is realized. In this case, the intake valve 3 is pressurized to be opened by the forward rotational drive of the cam 16, and on the contrary, the cam 16 before the head 16c of the nose portion 16b contacts the valve lifter 4. The intake valve 3 returns to the valve closing direction by starting the rear rotational drive of 16). Since the operating angle of the intake valve 3 can be appropriately changed by the forward and backward rotational driving of the motors 11 and 12, as shown in item D of FIG. 8, only the lift amount can be changed without changing the operating angle. .

Item E in FIG. 8 shows that the camshaft 17 and 30 are continuously rotated in one direction, the rotational speed of the camshaft is accelerated while the intake valve 3 is opened, and the crank angle and cam 16 while the intake valve 3 is closed. An example in which the lift speed is changed while maintaining the operating angle of the intake valve 3 by decelerating the rotational speeds of the cam shafts 17 and 30 so as to cancel the phase change due to the acceleration between them. Given the operating characteristics shown in item E of Fig. 8, the intake efficiency is improved by the quick opening of the intake valve 3, and the intake valve 3 is the valve seat by the deceleration of the lift speed when the intake valve 3 is closed. The impact that occurs when it comes in contact with can be mitigated.

Item F in FIG. 8 drives the camshafts 17 and 30 to rotate at twice the standard speed, i.e. at the same rotational speed as the crankshaft, so that the intake valve 3 is opened during the period in which the intake valve 3 is opened and closed once. An example is shown in which the operating cycle of the internal combustion engine 1A is changed from a four stroke cycle to a two stroke cycle by opening and closing a in two separate sets. In addition, item G of FIG. 8 is an example in which the intake valve 3 is opened early when 1 A of internal combustion engines perform stratified combustion. However, the lift amount is kept small for a certain time after the intake valve 3 starts to open. While the intake valve 3 is closed, the cam shafts 17 and 30 are accelerated above the standard speed to advance the opening timing of the intake valve 3, and then the rotation speed of the cam shafts 17 and 30 is reduced to a considerably low speed. Or by temporarily stopping the cam shafts 17 and 30 so that the increase in the lift amount is suppressed and the cam shafts 17 and 30 are accelerated to increase the lift amount after maintaining this state for a predetermined time. Is done. In addition, item H of FIG. 8 is an example in which the cam shafts 17 and 30 were stopped and the intake valve 3 was kept closed. The cam shafts 17 and 30 can be stopped while the nose portion 16b pushes the valve lifter 4 to keep the intake valve 3 open.

As described above, according to the valve drive device 10 of the present invention, the intake valve 3 can have various operating characteristics through speed control of the cam shafts 17 and 30 by the electric motors 11 and 12. . In addition, as described above, since the area X in which the nose portion 16b does not overlap is provided on the outer periphery of the cam shafts 17 and 30, the # 1 cylinder and # 4 operated by the electric motor 11 are provided. The valve opening period of the intake valve 3 in the cylinder does not overlap. Similarly, the valve opening periods of the intake valve 3 in the # 2 cylinder and the # 3 cylinder operated by the motor 12 do not overlap. Therefore, even if the correlation between the crank angle and the phase of the cam 16 is different from the relationship in the case where the cam axes 17 and 30 are continuously driven at the standard speed, for example, the area X of the cam axis 17 is While facing the valve lifter 4, that is, while the base circle 16a of the cam 16 on the cam shaft 17 of the # 1 and # 4 cylinders passes through the valve lifter 4, in the correlation As a result of changing the operating characteristics of the intake valve 3 of either the # 1 cylinder or the # 4 cylinder together with the speed control of the electric motor 11 by adjusting the speed of the electric motor 11 to offset the difference of The change in the operating state of one of the intake valves 3 does not affect the operating characteristics of the intake valve 3 of the other cylinder, so that the change in the operating characteristics can be controlled at will. Similarly, the same procedure can also be applied to # 2 cylinders and # 3 cylinders.

In the case where all of the cams 16 of the cylinder 2 are driven by one common electric motor, the region X does not exist, and the valve opening period of each intake valve 3 has another intake valve 3. It is to be noted that since the angle of operation of each intake valve 3 cannot be changed and the cam shafts 17 and 30 cannot be rotated in opposite directions, since they necessarily overlap with the valve opening period of. Thus, in items other than item A and item E of FIG. 8, the above advantages cannot be achieved. In addition, according to the valve drive device 10, it is possible to achieve various changes in operating characteristics as compared with when the intake valves 3 of all the cylinders 2 are driven by the same electric motor. In addition, since fewer motors are required as compared to the case where an electric motor is used for each cylinder, the valve drive device 10 can be miniaturized with a reduction in the number of parts included and has an advantage in cost.

In the valve drive device 10 according to the present embodiment, since the torque reducing mechanism 40 is used for each of the motion transmission mechanisms 14 and 15, the reduction in the drive torque applied to the electric motors 11 and 12 is achieved. The rated torque required for the electric motors 11, 12 can be reduced, resulting in miniaturization of the electric motors 11, 12 and a more compact valve drive device 10. 9 shows the valve spring torque (solid line) applied by the valve spring 5 to the camshaft 17 or 30, and the reverse torque applied by the torque reducing mechanism 40 to the camshaft 17 or 30. Dashed line) and crank angle. The abscissa indicates torque = 0, the torque applied in the direction opposite to the forward rotation of the cam 16 is represented by a positive sign (+), and the torque applied in the forward rotation direction of the cam 16 is represented by a negative sign ( It is represented by-). 9 shows an example in which the cam shafts 17, 30 continue to drive forward at standard speed.

As shown by the solid line in FIG. 9, the valve spring torque is approximately zero where the cam 16 positions the intake valve 3 at the maximum lift amount. Since the repulsive force of the valve spring 5 pushes the cam 16 in the reverse rotation direction, the valve spring torque is positive before reaching the maximum lift amount, that is, during the opening of the intake valve 3. Since the repulsive force of the valve spring 5 pushes the cam 16 in the forward rotation direction, the valve spring torque is negative after reaching the maximum lift amount, that is, in the closing process of the intake valve 3. On the other hand, as shown by the broken line in Fig. 9, the antiphase torque is approximately zero at the maximum lift positive position, negative before reaching the maximum lift positive position, and positive after reaching the maximum lift positive position. In the opening process of the intake valve 3, the lifter 43 advances to the bottom 41c of the groove 41b, and the repulsive force of the coil spring 45 drives the antiphase cam 41 in the forward rotational direction. 43 is applied to the reverse phase cam 41, while in the closing process of the intake valve 3, the lifter 43 moves away from the bottom 41c of the groove 41b and the coil spring 45 Repulsive force is applied to the antiphase cam 41 via the lifter 43 to push the antiphase cam 41 in the reverse rotation direction.

Accordingly, the valve spring torque applied to the cam shafts 17 and 30 on the cam 16 side, that is, the valve spring 5 and the cam 16 to the cam shafts 17 and 30 through the valve lifter 4 and the cam 16. Losing torque and the reverse phase torque applied to the cam shafts 17 and 30 on the side of the antiphase cam 41, that is, the torque portion of the coil spring 45 of the unit 42 via the lifter 43 and the antiphase cam 41. Are applied in opposite directions to cancel each other out. Since the combined torque from the valve spring torque and the antiphase torque is applied to the electric motors 11 and 12 as the drive torque, the drive torque applied to the electric motors 11 and 12 is reduced, thereby the electric motors 11 and 12. The rated torque required for the motor is reduced to achieve miniaturization of the electric motor. Since an antiphase cam 41 is used for each camshaft 17, 30 and each antiphase cam 41 is shared by two cylinders 2, an antiphase cam for each cylinder 2 is selected. Compared with the use case, the torque reduction mechanism is also miniaturized, thereby achieving the valve drive device 10 in a more compact form. Although the case in which the cam shafts 17 and 30 are driven to continue to rotate at the standard speed has been described above, the relationship between the valve spring torque and the antiphase torque is in an antiphase relationship with each other, so that the speed or the rotation direction is changed The same effect on the reduction of the drive torque is also obtained. In addition, although only valve spring torque is considered as the target to be canceled by the antiphase torque, the antiphase torque can be determined by further considering the torque generated due to the inertia of the cam 16 or the like.

Next, the control of the electric motors 11 and 12 will be described in detail with reference to FIGS. 10 to 17. The operation of the electric motors 11 and 12 is assumed to be controlled by the electronic control unit 6 (ECU) as shown in FIG. The electronic control unit 6 is a computer unit containing peripheral devices such as a microprocessor and a memory required for the operation of the microprocessor. The electronic control unit 6 can be used as a unit such as a dedicated unit for controlling the electric motors 11 and 12 or an engine control unit also used for other purposes. In FIG. 10, the other parts except for the ECU 6 are the same as the parts of FIG. 1.

In the following, the control of the electric motor 11 for the first group cylinders (# 1 cylinder and # 4 cylinder) will be described, but unless otherwise stated, the electric motor for the second group cylinders (# 2 cylinder and # 3 cylinder) 12 can be controlled in the same manner. Further, when the cam 16 and the camshaft 17 are driven to continue to rotate in one direction at the standard speed, the intake valves 3 of the # 1 cylinder and the # 4 cylinder are 360 ° as shown in Fig. 2B. Opened and closed at intervals of .CA, the operating angle of each valve 3 is set to 240 ° .CA (referred to as the standard operating angle), and changes in lift amount and operating angle are described in relation to this state. . That is, the profile of the cam 16 is designed such that the working angle of the intake valve 3 is set to 240 ° CA. The waveform of the lift amount shown in broken lines in FIGS. 11, 12, 15, and 16 corresponds to the waveform when the cam speed is fixed at the standard speed. In these figures, the notation 'CA' for the crank angle is omitted.

[Variable control of working angle]

The ECU 6 controls the rotation of the electric motor so that the cam shaft continues to rotate in one direction and the rotation speed of the cam shaft 17 is appropriately changed, so that the characteristics of the operating angle and the lift amount of the intake valve 3 change. do. 11 shows an example in that case. FIG. 11 shows the rotational speed of the output shaft 11a of the electric motor 11 at intervals of 360 °. CA while driving the camshaft 17 continuously and in a single direction to drive the intake valve 3 to open and close. The relationship between the cam speed (rotational speed of the cam 16), the lift amount of the intake valve 3, and the crank angle when the operating angle of the intake valve 3 changes by changing is shown. In this example, the cam speed changes at intervals of 360 ° CA so that the cam speed is maximum while the intake valve 3 is open. Further, the area S1 where the cam speed exceeds the standard speed between the time t1 at which the intake valve 3 starts to open and the time t2 at which the valve is closed is the area where the cam speed falls below the standard speed ( The cam speed is changed to be larger than S2). Therefore, the operating angle of the intake valve 3 becomes smaller than the standard operating angle. Further, the position at which the lift amount of the intake valve 3 becomes maximum when the cam speed is fixed at the standard speed is set to the position at which the cam speed is maximum. In addition, the waveform of the cam speed of one cycle is symmetrical in the transverse direction with respect to the position where the cam speed is maximum.

FIG. 11 shows the cam speed at the maximum position (maximum lift position) at the position where the lift amount of the intake valve 3 is maximum (maximum lift position) when the nose head 16c of the cam 16 passes the valve lifter 4. The example in which the phase of the cam speed change of is changed is shown. By changing the phase as described above, the area S2 of FIG. 11 is reduced or disappeared. This increases the amount of reduction in the operating angle relative to the standard operating angle. The maximum reduction amount is achieved by controlling the area S2 to disappear.

In the example shown in Fig. 13, the cam speed is changed at 360 °. CA intervals so that the cam speed is minimized while the intake valve 3 is opened. That is, the cam speed varies symmetrically in the longitudinal direction with respect to the standard speed corresponding to the cam speed change in FIG. Therefore, between the time t1 at which the intake valve 3 starts to open and the time t2 at which the valve is closed, the area S1 where the cam speed exceeds the standard speed is the area where the cam speed falls below the standard speed. Is smaller than (S2). Thus, the operating angle of the intake valve 3 becomes larger than the standard operating angle. In addition, in the example shown in FIG. 13, the phase of the cam speed change can be further changed so that the cam speed is minimum at the position of the maximum lift amount of the intake valve 3. According to this configuration, the amount of increase in the operating angle with respect to the standard operating angle may increase.

Also, for example, the cam amount is accelerated while the lift amount of the intake valve 3 is increased and the cam speed is lowered while the lift amount is decreased, so that the operating angle matches the standard operating angle or suppresses the difference between them. The waveform of the change is set to be symmetrical before and after the maximum lift position. By performing the above control operating at 360 ° .CA intervals, the operating angle or lift characteristic of the intake valve 3 used for each of # 1 and # 4 cylinders can be changed. Since the cam speed changes at intervals of 360 ° CA, the change in the operating characteristic of the intake valve 3 of one cylinder does not affect the change in the operating characteristic of the intake valve of the other cylinder.

[Variable lift control]

The ECU 6 swings the output shaft 11a of the electric motor 11 in two directions opposite to each other so that the rotational direction of the cam 16 is changed, i.e., predetermined rotation while the intake valve 3 is opened. It is possible to change the maximum lift amount of the intake valve 3 by alternately changing the rotational direction of the output shaft 11a for each. An example of the operation of the cam 16 in this case is shown in Figs. 14A to 14C. In Figs. 14A to 14C, the solid line shows the cam 16 and the valve lifter 4 for cylinder # 1, and the broken line shows the cam 16 and the valve lifter 4 for cylinder # 4. In the swing control, for example, the valve lifter 4 is pushed down through the nose portion 16b of the cam 16 by rotating the cam 16 of the cylinder # 1 in the direction indicated by the arrow A in FIG. 14A. Then, the rotation direction of the cam 16 is reversed in the direction of the arrow B before the nose head 16c of the cam 16 reaches the valve lifter. Then, the rotational direction of the cam 16 is maintained such that the region X shown in FIG. 5 passes through the valve lifter 4 as shown in FIG. 14B. Thereafter, the rotational direction of the cam 16 is maintained, and the valve lifter 4 is pushed down by the nose portion 16b of the cam 16 of the # 4 cylinder as shown in Fig. 14C. Before the nose head 16c of the cam 16 of the # 4 cylinder reaches the valve lifter 4, the rotational direction of the cam 16 is reversed again in the direction of the arrow A. By repeating this rocking motion, the intake valve 3 of each cylinder is opened and closed continuously while limiting the peak lift amounts of each of the # 1 cylinder and the # 4 cylinder to the maximum lift amount or less.

FIG. 15 shows the relationship between the rotational angle (cam angle) of the cam, the cam speed, the lift amount of the intake valve 3 and the crank angle in the rocking control. The cam angle is the nose portion 16b of the cam 16 with respect to the state where the line passing through the center of the base circle 16a and the base circle 16a intersects and the nose head 16c faces the valve lifter 4. ) Is defined as positive when the cam rotates in the direction of pushing the valve lifter 4 downward, that is, in the direction of the arrow A in FIG. 14A. Cam speed is also defined in the same way.

In the example shown in FIG. 15, the cam 16 is rotated while the base circle 16a of the cam 16 of the # 1 cylinder faces the valve lifter 4 (when the crank angle is 0 to 60 °. CA). During a certain period of time when the nose portion 16b starts to push the valve lifter 4 downward, that is, when the intake valve 3 starts to be lifted, the cam 16 is moved at a standard speed (the arrow in FIG. Corresponding to rotation in the direction A). After that, the cam 16 starts to decelerate in the process of lifting the intake valve 3, and then the cam stops temporarily (the position in FIG. 15 where the cam speed is 0 and the lift amount of the # 1 cylinder is the maximum). , The rotation direction of the cam 16 is reversed. After reversing, the cam speed increases at the standard speed, and the rotational speed (corresponding to the rotation in the direction of the arrow B in Fig. 14A) is maintained until the intake valve 3 is closed. Under the above control, the cam 16 oscillates within a range of less than 180 ° CA. The peak lift amount of the intake valve 3 of the # 1 cylinder is suppressed to less than the maximum lift amount.

In the swing control, the peak lift amount of the intake valve 3 can be appropriately changed by changing the swing range of the cam 16. In Fig. 15, the peak lift amount of the intake valve 3 increases by the rotational angle (swing amount) of the cam 16 from the start of lifting until the cam speed becomes zero, while the peak lift amount decreases by the amount of swing. The swing range is within the maximum lift position of each # 1 cylinder and # 4 cylinder, ie, the position where the nose head 16c of each cam 16 of the # 1 and # 4 cylinders passes the valve lifter 4. Can be adjusted from

On the other hand, in the swing control, the operating angle of the intake valve 3 can be changed larger or smaller than the standard operating angle by adjusting the rotational speed of the cam 16 at the time of swinging. In the example shown in FIG. 15, the operating angle is controlled to be less than the standard operating angle. When the lift amount is suppressed to less than the maximum lift amount, the intake amount can be suppressed by further controlling the operating angle to less than the standard operating angle as well as suppressing the lift amount, and thus the valve opening area of the intake valve 3 (lift amount The area enclosed by the abscissa indicating the waveform line and the crank angle) is kept small. When the internal combustion engine 1A is thus controlled at low load low speed rotation, the pumping loss can be reduced by increasing the opening level of the throttle valve used in the intake system of the internal combustion engine 1A.

In the case where the operating angle of the intake valve 3 of the # 1 cylinder is changed with respect to the standard operating angle, when the cam speed is maintained at the standard speed until the intake valve 3 of the # 4 cylinder starts to be lifted, # 4 The lift start timing of the intake valve 3 of the cylinder is changed with respect to the time set after 360 ° .CA from the originally planned timing, that is, the lift start timing of the intake valve 3 of the # 1 cylinder due to the change in the operating angle. Therefore, in Fig. 15, after the intake valve 3 of the # 1 cylinder is lifted, the cam speed is temporarily lowered until the intake valve 3 of the # 4 cylinder starts to be lifted, so that the intake valve of the # 4 cylinder ( 3) will start lifting at 420 ° .CA. In the speed control of the cam 16, after the intake valve 3 of the # 4 cylinder starts to be lifted, only the direction of rotation becomes different, and the speed is the same as in the # 1 cylinder.

In the example shown in FIG. 15, opening and closing of the intake valve 3 is controlled using only one side of the nose head 16c of the cam 16 used for each cylinder. In order to equalize the uneven lubrication between the cam 16 and the valve lifter 4 and the uneven wear of the cam 16, the swing range of the cam 16 is on both sides of the nose head 16c of the cam 16. Both (C1 and C2 in Fig. 14A) can be switched at appropriate intervals to drive the intake valve 3. This transition period can be determined according to variables such as swing time and frequency. Also, when the range is switched, the nose head 16c of the cam 16 must pass over the valve lifter 4. The rocking control of the electric motor 11 and the control of the continuous rotation of the electric motor 11 in one direction cause the operating state of the internal combustion engine 1A, for example, the cam 16 to be rocked at low load low speed rotation by the electric motor 11. And when the cam 16 is selectively used by the electric motor 11 to continue to rotate in one direction at high load and high speed rotation, the area of the cam 16 to be used is switched before and after continuous rotation.

[Control of partially deactivated cylinder operation]

In low speed operation or low load operation of the internal combustion engine, by keeping the intake valves of some cylinders closed, it may be necessary to reduce cylinder operation in which combustion stops in some cylinders. A specialized valve stopper is required for the reduction cylinder operation of a mechanical valve drive that transmits the rotation of the crankshaft to the valve. However, according to the valve drive device 10 of the present embodiment, since each pair of cams 16 driven by the same electric motors 11 and 12 has the above area X, it is possible through the ECU 6. Reduction cylinder operation is easily achieved by rocking the electric motors 11, 12 in the opposite two directions or by stopping the motor. Some examples are described below.

FIG. 16 shows an example in which combustion in the # 4 cylinder is stopped by rocking the electric motor 11 in two opposite directions. In this example, the cam speed and cam angle are controlled in the same manner as in FIG. 15 until the lifting of the intake valve 3 of the # 1 cylinder is finished. After the lifting of the intake valve 3 of the # 1 cylinder is finished, the cam 16 is decelerated and stopped at the end point (360 °. CA) of the control period of the electric motor associated with the # 1 cylinder. At this point, the cam angle is zero, and both the cams 16 of the # 1 and # 4 cylinders are positioned so that the base circle 16a faces the valve lifter 4. The cam 16 has stopped from this state to the end point 720 °. CA of the control period of the electric motor 11 associated with the # 4 cylinder. After that, the intake valve 3 of the cylinder # 1 is lifted again. Through the above control, the intake valve 3 of the # 4 cylinder can be stopped in a closed state while opening and closing the intake valve 3 of the # 1 cylinder. The intake valve 3 of the # 4 cylinder can be opened and closed and the intake valve 3 of the # 1 cylinder can be kept closed.

17A by stopping the electric motor 11 at 0 °. CA to 720 °. CA with the region X facing the valve lifter 4, i.e., the intake valves of the cylinders of the same group are all closed. Any intake valve 3 of the same cylinder group (e.g., # 1 cylinder and # 4 cylinder) can be stopped as shown in FIG. In this case, since the electric motor 12 drives each cam 16 of the other cylinder group (# 2 cylinder and # 3 cylinder) so that the intake valve 3 of the cylinder is opened and closed, non-combusting two cylinders The remaining two # 2 cylinders and # 3 cylinders will be burned at 360 ° .CA intervals. Further, the electric motor 12 can stop where the intake valves 3 of the # 2 cylinder and the # 3 cylinder are both closed, while the electric motor 11 has a # 1 cylinder and a cylinder to open and close the intake valve 3. The cam 16 of the # 4 cylinder can be driven.

Alternatively, in reduction cylinder operation, the swing and stop of the electric motors 11 and 12 can be combined to suitably change the number of non-operating cylinders within a range 1 to 3 less than the total number of cylinders. For example, FIG. 17B shows an example in which only # 1 cylinder has stopped combustion and FIG. 17C shows an example in which # 1 cylinder and # 3 cylinder have stopped combustion. Preferably, the number of non-combustion cylinders that do not burn and the non-combustion cylinders are selected according to the operating state of the internal combustion engine 1A. Since the non-combustion cylinder is relatively easily selected as above, the pumping loss in the reduction cylinder operation is reduced and the internal combustion engine 1A can be operated in a high efficiency state. Therefore, fuel efficiency is improved. Further, while a part of the cylinder is not burned, in the combustion cylinder, the operating angle and lift amount of the intake valve 3 can be changed by the above control. In this case, the engine braking force is adjusted more frequently because the pumping loss in the internal combustion engine 1A can be controlled more accurately than when the cam 16 of the combustion cylinder continues to rotate at the standard speed.

In the above description, the operating characteristics of the intake valve 3 are described in relation to the rotational speed or the rotational direction of the cam 16. However, considering the reduction ratio or rotation direction relationship between the electric motors 11 and 12 and the cam 16, the rotation speed or rotation direction of the cam 16 is determined by the output shafts 11a, 12a) can be replaced by the rotational speed or direction of rotation, respectively. The operating characteristic of the intake valve 3 can be changed through the control of the electric motors 11, 12 by the ECU 6 in accordance with the replaced rotational speed and the rotational direction of the output shafts 11a, 12a. For example, the rotational speed of the cam 16, the rotational direction, the operation control mode (the control mode and the rocking control mode which continue to rotate in one direction) and the swinging range in the rocking control mode (the cam angle or the rocking angle at the point where the rotational direction changes) Information on the operation state of the internal combustion engine 1A and the operation of the cam 16, such as the relationship of the internal combustion engine 1A, is stored in advance in the ROM of the ECU 6, The operating state is determined by The operating state of the cam 16 is specified by the determined result. By controlling the electric motors 11, 12 having the operating characteristics of the output shaft replaced by the operating characteristics of the output shafts 11a, 12a, operation such as the operating angle, the lift characteristic, the maximum lift amount, and the number of non-combustion cylinders Can change the characteristics. In this case, since the crank sensor or the cam angle sensor detects the crank angle or the rotation position of the cam shafts 17 and 30, the electric motors 11 and 12 are subjected to feedback control.

The present invention is not limited to the above embodiments and may be modified or changed. For example, although a series four-cylinder internal combustion engine is described in the present invention, a plurality of cylinders may be used when all the cylinders whose valve opening periods do not overlap are separate from each other in a group of cylinders. 18 shows a V-type six cylinder internal combustion engine 1B in which a valve drive device 50 is used. In this internal combustion engine, cylinders 2 (# 1, # 3, # 5) and cylinders 2 (# 2, # 4, # 6) have one bank 51 and another bank 52. Are arranged in a row. Ignition occurs in the order of cylinder number, i.e. # 1 → # 2 → # 3 → # 4 → # 5 → # 6. In addition, since the bank angle is set to 60 °, the ignition shock occurs every 120 ° CA.

In the valve drive device 50 applied to the internal combustion engine 1B, since the cylinders at intervals of 360 ° CA from the other cylinders form a group of cylinders, three motors 53, 54, 55). When the standard working angle is 240 °. CA, the lift amount of each intake valve corresponds to the crank angle as shown in Fig. 19A. Thus, in FIG. 18, the first group cylinder includes # 1 cylinder and # 4 cylinder, the second group cylinder includes # 2 cylinder and # 5 cylinder, and the third group cylinder includes # 3 cylinder and # 6 cylinder And three motors are provided to the first group cylinder, the second group cylinder, and the third group cylinder.

The rotational motion of the first electric motor 53 is transmitted to the cam 16 for the # 1 cylinder and the # 4 cylinder via the transmission mechanism 58 including the gear train 56 and the cam shaft 57. The rotational movement of the second electric motor 54 is transmitted to the cam 16 for the # 2 cylinder and the # 5 cylinder via the transmission mechanism 61 including the gear train 59 and the cam shaft 60. The rotational movement of the third electric motor 55 is transmitted to the cam 16 for the # 3 and # 6 cylinders via a transmission mechanism 64 including the gear train 61 and the cam shaft 63. The camshaft 60 for # 2 cylinder and # 5 cylinder is the same as the camshaft 17 of FIG. 3 and FIG. The cam shafts 57 and 63 are hollow shafts which are coaxially located on the outer circumference of the cam shaft 60 and can rotate. Camshafts 57, 60, 63 are located between banks 51 and 52 and the rotation of each of the cams 16 for camshafts 57, 60, 63 is linear to the follower (not shown). Switch to exercise The linear motion of the follower is transmitted to a valve including an intake valve via a motion transfer unit such as a push rod, and the valve reciprocates. The internal combustion engine 1B shown in FIG. 18 is an OHV equation.

In this configuration, the valve opening period in each cylinder group is also not overlapped as in FIG. 2A, and the miniaturized valve driving device is achieved because the number of electric motors involved decreases as the operating characteristics of each valve are improved. Done. In addition, the cams 16 of the same cylinder group can be controlled in the same manner as above. In FIG. 18, each camshaft 57, 60, 63 has a torque reducing mechanism 40.

In FIG. 18, a group of cylinders has two cylinders, but when the standard operating angle is set to 180 °. CA, as shown in FIG. 19B, the valves of the # 1 cylinder, the # 3 cylinder, and the # 5 cylinder are opened. The periods do not overlap, and the valve opening periods of the # 2 cylinder, the # 4 cylinder, and the # 6 cylinder also do not overlap. In this case, the first group cylinder may be composed of # 1 cylinder, # 3 cylinder and # 5 cylinder, and the second group cylinder may be composed of # 2 cylinder, # 4 cylinder and # 6 cylinder, and The valve drive device 10 according to this can be applied to this configuration. That is, a cylinder group may be included for each bank in the present invention.

20 shows another embodiment in which the valve drive is applied to a V-type six cylinder internal combustion engine. In this embodiment, the cam carriers 71 and 72 are provided in the pair of banks 51 and 52 respectively. Each cam carrier has two cam shafts 73 and 74 for operating the intake valve 3 and one cam shaft 75 for operating the exhaust valve (not shown). All cam axes are fixed to the same axis on the corresponding carrier, are rotatable and located on the same axis. In FIG. 20, the camshaft 74 of the bank 51 is separated from the cam carrier 71, but in practice, the camshafts 73, 74 are similar to the camshaft 74 on the cam carrier 72. 71) on the same axis.

The cam 16 is integrally formed with the cam shaft 73 and can rotate to operate the intake valve 3 corresponding to two adjacent cylinders 2 of one bank. The cam 16 is formed integrally with the other cam shaft 74 and can rotate to operate the intake valve 3 corresponding to the remaining cylinders 2 of the same bank. The cam shaft 73 is rotated by the first electric motor 11 via the first transmission mechanism 14, and the cam shaft 74 is connected to the second electric motor 12 via the second transmission mechanism 15. Rotate by. The cam 76 is integrally formed with the cam shaft 75 for the exhaust to operate the exhaust valves of all the cylinders in one bank and can be operated. The camshaft 75 rotates by one electric motor 78 via the transmission mechanism 77. Since the cams 16 for each cylinder 2 have a phase difference of 120 ° from each other, the operating characteristics of the intake valves 3 in the two cylinders 2 depend on the rocking control of the first motor 11. Can be controlled independently, and the operating characteristics of the intake valve 3 in the remaining cylinders 2 are independently controlled by the second motor 12 irrespective of the intake valves 3 of the two cylinders 2. Can be.

The present invention can be applied to a series 6 cylinder, V type 8 cylinder, or V type 12 cylinder internal combustion engine. In the in-line six-cylinder internal combustion engine 1C shown in FIG. 21, the cylinder 2 is numbered # 1 to # 6 from one end to the other end, and the ignition sequence of the cylinder is # 1 → # 5 → # 3 → # 6 → # 2 → # 4. FIG. 22A shows the relationship between the lift amount and the crank angle of each intake valve when the standard operating angle of each cylinder valve is 240 ° CA. In this case, the first group cylinder, the second group cylinder, and the first The group 3 cylinders are composed of # 1 and # 6, # 2 and # 5, and # 3 and # 4 cylinders, respectively, and a valve drive device according to the present invention can be applied to this configuration. FIG. 22B shows the relationship between the lift amount and the crank angle of each intake valve when the standard operating angle of each intake valve is set to 180 °. CA in the series 6-cylinder internal combustion engine 1C. The group 1 cylinder and the group 2 cylinder are composed of # 1, # 2, and # 3 cylinders and # 4, # 5, and # 6 cylinders, respectively, and the ignition sequence is # 1 → # 4 → # 2 → # 6 → # 3 → # 5 and the valve drive can also be applied to this configuration.

When applied to a V-type 8 cylinder internal combustion engine, since the four cylinders are arranged in series in each bank, the above embodiment can be used considering each bank as a series 4 cylinder internal combustion engine. In the V-shaped 12-cylinder internal combustion engine, since six cylinders are arranged in a row in each bank, the above embodiment can also be used by considering each bank as a series 6-cylinder internal combustion engine. In addition, when the variable cylinder control is executed, the number of non-combustion cylinders can be selected within 1 to 5 in a 6 cylinder internal combustion engine, within 1 to 7 in an 8 cylinder internal combustion engine, and within 1 to 11 in a 12 cylinder internal combustion engine.

As described above, in the present invention, it is preferable that the number of cylinders opened by one motor and combinations thereof and the number of electric motors are determined so as not to overlap in the order of the valve opening periods with respect to the adjustable amount of the operating angle. . That is, even when the operating angle changes, the number of cylinders opened by one motor and their combination and the number of electric motors can be determined so that the valve opening period does not overlap in the group of cylinders. The embodiment does not limit the number of electric motors, the number of cylinders and their arrangement, and the combination of cylinders controlled by one motor.

Although an intake valve 3 is shown in the above embodiment, the present invention may be applied to an exhaust valve. According to the present invention, the operating state of the internal combustion engine can be controlled by controlling the exhaust valves and changing the exhaust efficiency of each cylinder. In addition, both the intake valve and the exhaust valve can be controlled according to the present invention. The reducers 18, 31 may not be essential to the embodiment according to the invention or may be directly connected to the output shafts 11a, 12a and the cam shafts 17, 30. Preferably, the reduction ratios of the reducers 18, 31 are set at the same level in order to easily control the speeds of the electric motors 11, 12. The torque reduction mechanism 40 may not be essential to the embodiment according to the present invention. In the case of providing the torque reduction mechanism 40, the antiphase cam 41 may not be necessarily provided to an intermediate gear such as the cam shafts 17 and 30 and may be provided to the reducer 18 and 31. In this case, however, the rotational speed of the antiphase cam 41 should be an integral multiple of the rotational speed of the cam shafts 17, 30. The motion switching device is not limited to the cam mechanism 13 but may be a link mechanism such as a slider crank mechanism, in which case the rotating body of the rotation input portion of the link mechanism can be driven by an electric motor.

As described above, with the valve drive device according to the present invention, flexibility in controlling the operating characteristics of the valve of each cylinder can be improved. Further, according to the present invention, the valve drive device can be miniaturized compared to when an electric motor is provided in each cylinder and can be easily mounted in a vehicle.

Claims (18)

A valve drive device for a multi-cylinder internal combustion engine that converts a rotational motion output from a valve driving source into a linear motion through a motion conversion device provided in each cylinder, and drives a valve of each cylinder in a linear motion. A valve driving apparatus for a multi-cylinder internal combustion engine comprising an electric motor shared as a valve driving source of a cylinder group including a plurality of cylinders in which the valve opening period of the valve does not overlap. The method of claim 1, And a motion transmission mechanism for transmitting the rotational motion of the electric motor to the rotating bodies of the respective motion conversion devices of the cylinder group. The method according to claim 1 or 2, A torque reduction mechanism for reducing the drive torque generated when driving each valve of the cylinder group is shared with the cylinder group, characterized in that the valve drive device for a multi-cylinder internal combustion engine. The method of claim 2, The movement transmission mechanism is provided with a transmission shaft for connecting the rotation bodies of the respective motion conversion devices of the cylinder group to each other, The electric motor is a valve drive device for a multi-cylinder internal combustion engine, characterized in that connected to the movement transmission shaft to transmit the rotational movement to the movement transmission shaft. The method of claim 2, The internal combustion engine is configured as an equally spaced ignition series four cylinder four stroke cycle internal combustion engine, The ignition gap between the outer cylinder pair is set to crank angle 360 ° in the order of ignition of the cylinders, The internal combustion engine is provided with a first electric motor shared with the motion switching device of the first group cylinder composed of the outer cylinder pair as an electric motor and a second electric motor shared with the motion switching device of the second group cylinder composed of the inner cylinder pair. It is The motion transmission mechanism transmits the rotational motion of the first motion transmission mechanism and the second electric motor to transmit the rotational motion of the first electric motor to the rotary bodies of the respective motion conversion devices of the first group cylinder. A valve drive device for a multi-cylinder internal combustion engine, characterized in that it comprises a second movement transmission mechanism for transmitting to the rotating body of the movement switching device. The method of claim 5, wherein The first motion transmission mechanism includes a first motion transmission axis connecting the rotation bodies of the respective motion conversion devices of the first group cylinders, and the second motion transmission mechanism includes the rotation body of each motion conversion device of the second group cylinders. A second exercise transmission axis connecting the The second exercise transmission axis is coaxially located outside the first exercise transmission axis, The first electric motor is connected to the first motion transmission axis to transmit rotational motion to the first motion transmission axis, And the second electric motor is connected to the second motion transmission shaft to transmit rotational motion to the second motion transmission shaft. The method of claim 2, The internal combustion engine is composed of an equally spaced ignition six-cylinder four-stroke cycle internal combustion engine, The cylinder group consists of cylinders whose ignition timing between each cylinder is set to crank angle 360 ° in the ignition order of the cylinders, The electric motor and the transmission mechanism are provided in each cylinder, the valve drive device for a multi-cylinder internal combustion engine. The method according to any one of claims 2 to 6, The motion conversion device is composed of a cam mechanism, And said rotating body is a cam of a cam mechanism. The method of claim 1, And a control device for controlling the operation characteristic of each valve of the cylinder group by changing one or more rotational speeds and rotational directions of the electric motor. The method of claim 9, Further comprising a cam mechanism for converting a rotational motion output from the electric motor into a linear motion of the valve, The control device controls the electric motor so that the cam of the cam mechanism continues to rotate in the same direction while changing the rotational speed so that the rotational speed of the cam driving each valve becomes maximum or minimum when the lift amount of the valve is maximum. A valve drive device for a multi-cylinder internal combustion engine, characterized in that. The method of claim 9, Further comprising a cam mechanism for converting a rotational motion output from the electric motor into a linear motion of the valve, Each cylinder group consists of two cylinders, The electric motor changes the swing amount within a range between the position where the maximum lift amount is given by the cam of the cam mechanism of the cylinder of the cylinder group and the position where the maximum lift amount is given by the cam of the cam mechanism of another cylinder of the cylinder group. And the control device drives the electric motor to oscillate in two opposite directions. The method of claim 11, The control device is a valve drive device for a multi-cylinder internal combustion engine, characterized in that further changes the rotational speed of the electric motor during swinging. The method according to claim 11 or 12, And the control device controls the electric motor to alternately use both sides of the head of the nose portion of the cam of the cylinder group during valve driving. The method of claim 9, The control device oscillates the electric motor in two opposite directions such that in reduction cylinder operation of the internal combustion engine the valves of one cylinder of the cylinder group are opened and closed and the valves of the other cylinders of the same cylinder group are closed. Valve drive device for engines. The method of claim 9, The electric motor is provided as a valve driving source to each cylinder group consisting of a plurality of cylinders that do not overlap the valve opening period, The control device oscillates at least one electric motor in two opposite directions such that in reduction cylinder operation of the internal combustion engine the valves of one cylinder of the cylinder group are opened and closed and the valves of the other cylinders of the same cylinder group are closed. Valve drive device for multi-cylinder internal combustion engines. The method of claim 9, The electric motor is used as a valve driving source in each of a plurality of cylinder group consisting of a plurality of cylinders that do not overlap the valve opening period, And the control device stops a part of the electric motor in a position where all the valves driven by the respective motors are closed in the reduction cylinder operation of the internal combustion engine. The method according to claim 15 or 16, And the control device controls each electric motor such that the number of cylinders in which the valve is closed is less than the total number of cylinders in the reduction cylinder operation of the internal combustion engine. The method according to claim 15 or 16, The control device controls each electric motor such that in reduced cylinder operation of the internal combustion engine the number of cylinders in which the valve is closed is less than the total number of cylinders and the one or more lift amounts and operating angles of the cylinders change in the cylinder in which the valve is opened and closed. The valve drive device for a multi-cylinder internal combustion engine, characterized in that the.

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