JPS61155627A - Torque fluctuation restraining device of engine - Google Patents

Abstract

PURPOSE:To prevent excessive discharging of a battery by preventing actuation of a motor function consuming battery power by marking an electrical condition where motor function is not actuated in low rotation of an engine. CONSTITUTION:When a motor function is actuated, a torque fluctuation restraining device is to have a circuit structure similar to that of a normal electric motor and positive torque is provided to a crank shaft 1. When a power generating function is actuated, it is to have a circuit structure similar to that of a normal AC power generator and inverse torque is provided to the crack shaft 1, and a portion of engine power is converted into electric energy and charged in a battery. By switching motor function and power generating function properly, torque fluctuation of the crank shaft which becomes problem can be releaved in the range from low rotation to medium rotation of an engine. And at the time of low rotation of the engine when charging efficiency to the battery is relatively low, motor function consuming battery power is controlled not be actuated. Then, excessive discharging can be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a device for suppressing torque fluctuations occurring in an engine crankshaft.

(Prior Art) In an engine, particularly a reciprocating engine, since rotational torque is discontinuously applied to the crankshaft, torque fluctuations in the crankshaft inevitably occur.

This torque fluctuation has negative effects such as causing engine vibration, so it is desirable to minimize it as much as possible. Conventionally, as a device for suppressing such engine torque fluctuations, there is one described in Japanese Patent Application Laid-open No. 1431/1983.

This disclosed device includes a magnetic flux generating means that rotates together with the crankshaft and a magnetic flux generating means that cooperates with the magnetic flux generating means, and generates a magnetic torque that is almost in opposite phase to the explosive primary component of the rotational torque generated on the crankshaft. It is applied to the crankshaft. In this case, the fluctuation characteristics of the above primary explosion component are:
Since this changes depending on the number of cylinders in the engine, the number of poles of the magnetic torque generating means is controlled accordingly to generate magnetic torque that is approximately in phase opposite to the torque fluctuation characteristic.

(Problems to be Solved) The device described in Japanese Unexamined Patent Publication No. 55-1431 has a problem in that it constantly consumes electric power for generating magnetic torque, which places a new burden on the battery. This is particularly important at startup and at low rotation speeds because the load on the battery is large. Further, since the above device is specially configured as a torque fluctuation suppressing device, it is disadvantageous in terms of cost. Furthermore, in order to provide an appropriate magnetic torque, it is necessary to change the number of poles in accordance with the change in the number of cylinders, resulting in a problem that the device lacks versatility.

(Means for solving the above problems) The present invention is configured as follows in order to solve the above problems.

That is, the present torque fluctuation suppressing device includes a switching means that appropriately exhibits an electric function and a power generation function by switching the energization state, and a switching means that appropriately exhibits an electric function and a power generation function by switching the energization state, and a Timing control that controls the actuation timing of the switching means so that the power generation function is activated and reverse torque is applied to the crankshaft, and in response to the low torque period, the electric function is activated and positive torque is applied to the crankshaft. and a stop means for stopping the operation of the switching means when the engine rotates at low speeds and maintaining the switching means in an energized state in which no electric function is exerted.

(Function) The device of the present invention selectively exhibits a power generation function and an electric function by switching the energization state.

In this case, when the electric function is performed, the circuit structure is similar to that of a normal electric motor, and positive torque is applied to the crankshaft. In addition, when the power generation function is activated, the circuit structure is similar to that of a normal alternator, which applies reverse torque to the crankshaft, and part of the engine power is converted to electrical energy and charged to the battery. Ru. In the present invention, by switching the energization state, the electric function and the power generation function are appropriately exerted, thereby alleviating the crankshaft torque fluctuation that becomes a particular problem in the low to medium rotation range of the engine. In the switching control of the present invention, control is performed so that an electric function that consumes battery power is not performed when the engine has a relatively low charging efficiency at low revolutions.

(Description of Examples) Examples of the present invention will be described below with reference to the drawings.

Referring to FIGS. 1 to 3, a flywheel 2 is attached to the output side end of the crankshaft 1 of the engine E. As shown in FIG. A clutch mechanism 4 is combined with the side end surface of the flywheel 2, and the flywheel 2 and the clutch mechanism 4 are surrounded by a clutch housing 5 fixed to the side surface of the cylinder block 3 with bolts 3a. covered. A stator 6 is attached to the inside of the clutch housing 5 so as to surround the flywheel 2.

The stator 6 includes a supporter 6a and a stator coil 7 supported by the supporter 6a, and the stator coil 7 is arranged to face the outer peripheral surface of the flywheel with a constant gap therebetween. Note that two types of rotor coils, that is, an electric rotor coil 8 and a power generation rotor coil 9 are wound around the outer circumferential portion of the rotor, that is, the flywheel 2, and a magnetic body 10 is arranged. Referring also to FIG. 4, the electric rotor coil 8 is wound around the flywheel 20 in a meandering manner, and is connected to the crankshaft in the same manner as the electric wire of a normal motor. l
It is connected to a commutator 11 disposed above. Commutator 1
1 is adapted to come into contact with the brush 13. Further, as shown in FIG. 5, the power generation rotor coil 9 is also wound in a meandering manner on the outer peripheral surface of the flywheel in the same manner as the coil 8, and is connected to a slip ring 12. are combined to make contact.

A control circuit for controlling the stator coil 7, electric rotor coil 8, and power generation rotor coil 9 to cause the stator 6 and rotor, that is, the flywheel ++1 structure, to appropriately perform the electric function and power generation function will be explained. . In FIG. 6, the stator coil 7, the electric rotor coil 8, and the power generation rotor coil 9 are connected to a nozzle 22 via a control circuit 20.

The control circuit 20 is preferably configured to perform switching control between an electric state and a power generation state in response to a command from a controller 39 constituted by a microcomputer.
Switching circuit 27, timing mi iJj circuit 37.38
, stator coil drive circuit 25, power generation rotor coil drive circuit 26, current adjustment circuit 28, 29, rectifier circuit 3
Consists of 0.

has been done. A switching circuit 27 of the control circuit 20 is connected to a battery 22 via a key switch 21. In this case, the switching circuit 27 is connected to the starter switch terminal 21a of the key switch 21 on one side and the ignition switch terminal 21b on the other side. Further, the rectifier circuit 30 of the control circuit 20 is connected to the battery 22 via a fuse box 32, and the stator coil drive circuit 25 is directly connected to the battery 22. The electric rotor coil 8 is connected to the current IA rectifying circuit 28 of the control circuit 20 at --A via the contact points 33, 34 between the commutator 11 and the brushes 13, and is grounded at the other end. The power generating low coil 9 is connected via the contact points 35, 36 between the slip ring 12 and the brush 14 to the control circuit 200 and the power generating low coil drive 26 on the one hand.
and grounded on the other hand. The stator coil 7 has a three-phase structure, and both ends of each winding are connected to the stator coil drive circuit 25 of the control circuit 20. The switching circuit 27 is configured to issue a switching command signal in response to a command signal from the controller 39, and the stator recommendation circuit 25 operates upon receiving the switching command signal to switch the connection state of the stator coil 7. Further, the power generation rotor coil recommendation circuit 26 similarly operates in response to a command signal from the switching circuit 27 to switch the connection state of the power generation rotor coil 9. In this example, the drive circuits 25 and 26 are comprised of relay circuits. Switching circuit 27 and drive circuit 25.2
Timing control circuits 37 and 38 arranged between 6 and 6.
generates a command signal so that the drive circuits 25 and 26 operate at a predetermined timing in response to a signal from the controller 39 when the output from the switching circuit 27 is a predetermined value. Plus, electric current! The JI adjustment circuits 28 and 29 are adapted to adjust the currents to the electric rotor coil 8 and the power generation rotor coil 9, respectively. Further, a rectifier circuit 30 provided between the stator coil drive circuit 25 and the fuse 32 rectifies the three-phase alternating current generated in the stator coil by power generation and transmits the rectified power to the battery 22. The stator coil drive circuit 25 operates so that the connection terminal group 25a and the connection terminal group 25b are selectively closed at both ends of the stator coil 7,
The drive circuit 26 for the power generation rotor coil is a drive circuit 250
It operates in conjunction with the operation and opens and closes the contact 26a.

When the contact terminal group 25a of the drive circuit 25 is closed, one end of the stator coil 7 is directly connected to the battery 22, and the other end of the stator coil 7 is connected to the electric rotor coil 8, that is, the seventh In the figure, terminal a is connected. This connection state is similar to the circuit configuration of a normal DC series motor, and an electric function is exerted to provide torque to the crankshaft l. At this time, since the contact 26a of the power generation rotor coil drive circuit 26 is open, the power generation rotor coil is not energized and its function is not activated. Further, when the connection terminal group 25b of the drive circuit 25 is closed in response to a command signal from the switching circuit 27, the stator coil 7 is connected to the battery 22 via the rectifier circuit 30. At this time, the electric rotor coil 8 is disconnected, and the power generation rotor coil 9 is connected to the battery 22 via the switching circuit 27 and the key switch 21 because the drive circuit 26 operates and closes the contact 26a. The connected state, that is, the state in which the terminals are connected as shown in FIG. This connected state has a circuit configuration similar to that of a normal alternator, and the stator and loaf structure exhibit a power generation function.

The controller 39 includes a signal from a crank angle sensor 40 for calculating the engine speed and a negative pressure sensor 4 for detecting intake negative pressure for calculating the engine load.
1, and the controller 39 generates predetermined command signals to the timing control circuits 37 and 38 and the switching circuit 27 based on these signals.

A case in which the apparatus having the above configuration is applied to control including mitigation control of torque fluctuations of the crankshaft 1 will be explained with reference to the flowchart of FIG. 9.

When starting the engine, the switching circuit 27 is connected to the stator coil under the conditions that the start switch terminal 21a of the key switch 21 is in the connected state and that the engine speed r is smaller than the speed r that indicates the start of a complete explosion. A command signal is output so that the connection terminal group 25a of the drive circuit 25 becomes connected. And in this case, the timing control circuits 37, 38 do not change this signal. As a result, the stator coil 7 and the electric rotor coil 8
are connected in series to a battery 22, and the stator and rotor structures perform an electric function. That is, the structure functions as a starter and provides starting torque to the crankshaft 1.

Next, if the engine rotation speed r is larger than the predetermined rotation speed r2 (3000 rpm in this example), the switching circuit 27
outputs a command signal so that the connection terminal group 25b of the stator coil drive circuit 25 becomes connected, and the contact 26a of the power generation rotor coil drive circuit 26 becomes closed.

In this case, the timing control circuit inputs the signal from the switching circuit 27 to the drive circuit 25, 26 without modification. Therefore, the stator coil 7 is connected to the battery 22 via the rectifier circuit 30, and the power generation rotor coil 9 is connected to the battery 22 via the switching circuit 27 and the key switch 21, forming an alternator circuit structure and exhibiting a power generation function. . As a result, three-phase alternating current is generated in the stator coil 7,
This alternating current is rectified by a rectifier circuit 30 and applied to the battery 22 for charging.

Next, when the engine speed r is lower than the predetermined speed r2, so-called torque fluctuation control is performed to alleviate torque fluctuations around the crankshaft 1.

In this case, when the engine speed r is relatively low, the torque fluctuation is, for example, a sine curve with a crank angle of 180° as one cycle, as shown by the solid line in Figure 10A, due to the explosion torque in the explosion process in a four-cylinder engine. It has change characteristics similar to.

As the engine speed increases, the inertia torque due to the inertia force of the piston system increases, so the phase shifts by 90 degrees of crank angle compared to the characteristics at low speeds, as shown by the broken line in Figure 10A. Torque fluctuations with varying characteristics occur. Therefore, as the rotational speed increases, the magnitude of the torque fluctuation gradually decreases as the solid line characteristic and the broken line characteristic cancel each other out, and has an extreme value near the rotational speed r3 as shown in FIG. When the rotational speed further increases, the torque fluctuation shown by the broken line becomes dominant, and the magnitude of the torque fluctuation tends to gradually increase. Therefore,
In performing the torque fluctuation control of this example, the stator and rotor structures are made to exhibit their electric function to apply a positive torque to the crankshaft at the operation start timing θ3, and the power generation function is made to exhibit a reverse torque to the crankshaft. The operation start timing .theta.6 which gives the rotational speed r3 is controlled to be changed before and after the rotation speed r3. Note that in a high engine speed range where the engine speed exceeds the predetermined speed r2, it becomes difficult to perform torque fluctuation control and the demand for such control decreases, so in this example, torque fluctuation control is not performed. .

In the torque fluctuation control of this example, when the engine rotation speed r is less than or equal to the rotation speed r at which the amount of torque fluctuation is minimal, the operation start timing θ5, θ of the electric function and the power generation function,
are the values θ and 1.0 depending on the torque fluctuation in the low speed range, respectively.
．． 1, and when the rotation speed exceeds r, the operation start timings θ5 and θ8 are set to values θ5□ and θ1□ corresponding to torque fluctuations in the high-speed range. These values are stored in memory in advance as a map corresponding to the operating state.

Next, the operating period θL during which the electric function and power generation function are demonstrated
1, θt, are engine speed r and intake negative pressure, respectively.
is set as a function fs (r, v), f, (rSv). This functional characteristic varies depending on the engine type, but
Roughly speaking, the operating period θt3, θ is set to be longer on the low and high rotation side with the rotation speed r3 as the boundary, and the operating period θ0, θ is set to be longer as the load increases.
The crank angle θ at that time is within the time range in which the stator and rotor structures should exhibit their electric function in light of the torque fluctuation characteristics corresponding to the rotational speed r at that time, that is,
If it is within the range from the start of operation θ5 to the end of operation θ510Ls, the drive circuit 25 connects the connection terminal group 25a via the timing control circuit 37.

Further, the drive circuit 26 opens the contact 26a via the timing control circuit 38. As a result, the stator coil 7 and the electric rotor coil 8 are energized and the electric function is performed. That is, the main torque is applied to the crankshaft 1, and the portion where the torque fluctuation characteristics are relatively low (the portion where the reverse torque acts) is corrected. Also, the crank angle θ
is within the time range in which the power generation function should be performed, that is, from the start of operation θ1 to the end of operation θ2 + θL2, the connection terminal group 25b of the drive circuit 25
becomes connected, and the contact 26a of the drive circuit 26
closes. As a result, the power generation rotor coil 9 is energized and the power generation function is exhibited. In this case, a counter torque is applied to a portion where the torque fluctuation characteristic is relatively high to correct it. As described above, the electric function of the stator and rotor structures is activated during the operation period θ, at the timing shown in FIG. 10C.
10D, and a positive torque having characteristics as shown in FIG. 10D is applied to the crankshaft 1. In addition, the power generation function is the 10th B.
At the timing shown in the figure, the operating period θ5. is exerted to provide the crankshaft 1 with a reverse torque having characteristics as shown in FIG. 10D. As a result, as a whole, the torque fluctuation shown by the solid line characteristic in FIG. 10A is corrected as shown by the dashed line in FIG. 10A by appropriately adding the positive and negative additional torques shown in FIG. 10D, and the amount of fluctuation is reduced.

In addition, in the torque fluctuation control of this example, when the engine speed is lower than the predetermined rotation speed r4, the electric function is not performed and only the power generation function is performed, that is, the torque fluctuation control is performed only by reverse torque. I have to.

In this example, the flywheel is used as a component of the rotor, and the electric motor and generator are configured in a single structure, and this is used to control torque fluctuations, so that the control is directly applied to the crankshaft, so the control response is improved. is good.

(Effects of the Invention) According to the present invention, since the battery is charged when the power generation function is performed, the problem that the load on the battery increases due to the torque fluctuation control according to the present invention does not occur. Further, since energy can be sufficiently recovered by exerting the power generation function, it is not necessary to provide a separate generator. Therefore, it is advantageous in terms of space and cost.

Furthermore, when the engine rotates at low speeds with low charging efficiency, the electric function that places a burden on the battery is not activated, so the battery will not be over-discharged. Further, the torque fluctuation suppressing device of the present invention can be applied to engines having different numbers of cylinders without requiring any modification.

[Brief explanation of drawings]

FIG. 1 is a longitudinal cross-sectional view of a main part of an electric power generator according to an embodiment of the present invention, FIG. 2 is a cross-sectional view of the embodiment of FIG. 1, and FIG. Fig. 4 is a schematic diagram showing the winding state of the electric power rotor coil, Fig. 5 is a schematic diagram showing the winding state of the power generation rotor coil, and Fig. 6 is a perspective view of the engine according to the present invention. The control circuit diagram of the electric power generator, Fig. 7 is a schematic diagram showing the wiring structure to perform the electric function, Fig. 8 is a schematic diagram showing the wiring structure to perform the power generation function, and Fig. 9 is a schematic diagram showing the wiring structure to perform the electric power generation function. A flowchart of control using the electric power generating device of the invention, Fig. 10A is a graph showing the torque fluctuation of the crankshaft, Fig. 1OB is a graph showing the timing to exert the power generation function, and Fig. 10C is the graph to show the electric function. FIG. 10D is a graph showing the timing, and FIG. 11 is a graph showing the relationship between torque fluctuation amount and engine rotational speed change. DESCRIPTION OF SYMBOLS 1... Crankshaft, 2... Flywheel, 4... Clutch mechanism, 5... Clutch housing, 6... Stator, 7 ...
...Stator coil, 8...Rotor coil for electric power, 9...Rotor coil for power generation, 1O...
Magnetic material, 20... Control circuit, 22...
Battery, 39... Controller. Figure 4 Figure 7 Figure 5

Claims (1)

[Claims] An electric power generating device connected to the output shaft of the engine, a switching means for appropriately exerting the electric function and the power generation function by switching the energization state to the electric power generating device, and a relatively high torque period of the torque fluctuation characteristic of the crankshaft. The actuation timing of the switching means is such that the power generation function is activated in response to the low torque period and reverse torque is applied to the crankshaft, and the electric power function is activated in response to the low torque period and positive torque is applied to the crankshaft. and a stopping means that stops the operation of the switching means and maintains the switching means in an energized state in which the electric function is not exerted when the engine rotates at low speed. Device.