JPS61155625A - Torque fluctuation restraining device of engine - Google Patents

Abstract

PURPOSE:To prevent excessive discharge of a battery by interrupting when electrifying condition in which a motor function is provided over a predetermined time is continued in a device in which torque fluctuation due to switching of electrifying condition is releaved. CONSTITUTION:Current is flowed in a stator coil 8 and an electric rotor coil 8 to actuate a motor function and positive torque is provided to a crank shaft. Current is flowed in the stator coil 7 and the electric rotor coil 8 to obtain a circuit construction similar to that of a normal AC power generator and inverse torque is supplied to the crank shaft, and a portion of engine power is converted to electric energy and charged in a battery. Thus, electrifying condition is switched to actuate motor function and power generating function properly, then torque fluctuation of the crank shaft can be releaved in the range from low rotation to medium rotation of the engine.And when the circuit condition in which function of the motor is actuated is continued over a predetermined time in the running range except starting, electrification is stopped and excessive charge of the battery will not occur.

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 magnetism generation stage is controlled accordingly to generate magnetic torque that is approximately in phase opposite to the torque fluctuation characteristics.

(Problems to be Solved) The device described in Japanese Patent Application Laid-Open 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. Especially when starting
This is critical 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 torque fluctuation suppressing device of the present invention 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 performs the power generation function in response to a relatively high torque period of the torque fluctuation characteristic of the crankshaft. Timing control means for controlling the actuation timing of the switching means so that the function is exerted and reverse torque is applied to the crankshaft, and in response to the low torque period, the electric function is exerted and positive torque is applied to the crankshaft. and an energization stop means that cuts off the current if the energization state in which the electric function is exerted continues beyond a predetermined time when the starter switch is in the inactive state.

(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 generation i+i 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 to charge the battery. be done. 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, if the starter switch is in a non-operating state, that is, a circuit state in which the function of an electric motor is exerted in an operating range other than during starting continues for a predetermined period of time, the starter switch is not energized. stop.

(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 in a meandering manner on the circumferential surface of the flywheel 2, and is connected to the crankshaft in the same manner as the armature wiring of a normal motor. axis 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, the electric rotor coil 8, and the power generation rotor coil 9 to cause the stator 6 and rotor, that is, the flywheel structure, to appropriately perform the electric function and the power generation function will be described. In FIG. 6, a stator coil 7, an electric rotor coil 8,
The power generation rotor coil 9 is connected to a battery 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 271. It is configured to include a timing control circuit 37, 38, a stator coil drive circuit 25, a power generation rotor coil drive circuit 26, a current adjustment circuit 28, 29, and a rectifier circuit 30. The switching circuit 27 of the control circuit 20 is
It is connected to a battery 22 via a key switch 21. In this case, the switching circuit 27 is connected to the key switch 21 on the one hand.
The other end is connected to a starter switch terminal 21a, and the other end is connected to an ignition switch terminal 21b. Further, the rectifier circuit 30 of the control circuit 20 is connected to the fuse box 32 through the
The stator coil drive circuit 25 is directly connected to the battery 22. The electric rotor coil 8 has a commutator 11
Via contact points 33, 34 with the brush 13, it is connected on the one hand to the current regulating circuit 28 of the control circuit 20 and on the other hand to ground. The power generation rotor coil 9 is connected via contact points 35 and 36 between the slip ring 12 and the brush 14.
One side is connected to the power generation rotor coil drive circuit 26 of the control circuit 2o, and the other side is grounded. The stator coil 7 has a three-phase structure, and both ends of each winding are connected to a stator coil drive circuit 25 of a control circuit 2°. 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 drive 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 drive 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
．． 26, a timing control circuit 37.
38, when the output from the switching circuit aF27 is a predetermined value,
In response to a signal from the controller 39, a command signal is generated so that the drive circuits 25 and 26 operate at a predetermined timing. Furthermore, the current adjustment circuits 28 and 29 are configured 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 the power generation action 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, and the power generation rotor coil drive circuit 26 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.
5, and opens and closes the contact 26a.

When the contact terminal group 25a of the drive port 825 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. In FIG. 7, the terminal a is connected. This connection state is similar to the circuit configuration of a normal DC series motor, and the electric function is exerted and torque is applied to the crankshaft 1. 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 does not perform its function. 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 pantry 22 via the switching circuit 27 and the key switch 21 because the drive circuit 26 operates and closes the contact 26a. That is, the state in which the terminals are connected as shown in FIG. 8 is reached. This connection state is similar to that of a normal alternator (
It has a circuit configuration similar to that of an alternator, and the stator and rotor structures perform the 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 41 for detecting intake negative pressure for calculating the engine load.
and an ammeter 4 that detects the current flowing to the electric rotor coil 8.
2, 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 operates to drive 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 rotation speed r1 indicating the start state of complete explosion. A command signal is output so that the connection terminal group 25a of the circuit 25 becomes connected. And in this case, the timing control circuits 37, 38 do not change this signal. Thereby, the stator coil 7 and the electric rotor coil 8 are connected in series to the battery 22, and the stator and rotor structures exhibit an electric function. That is, the structure functions as a starter and provides starting torque to the crankshaft 1.

Next, when the engine rotation speed r is larger than the predetermined rotation speed rz (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, and this alternating current is rectified by the rectifier circuit 30, and the battery 22
and charging is performed.

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 FIG. It has change characteristics similar to.

As the engine speed increases, the inertia torque due to the inertia force of the piston system increases, resulting in a phase shift of 90'' crank angle compared to the characteristics at low speeds, as shown by the broken line in Figure 10A. Torque fluctuations occur that have varying characteristics.For this reason, as the rotational speed increases, the magnitude of the torque fluctuation gradually decreases as the solid line characteristics and the broken line characteristics cancel each other out, and as shown in FIG. It has an extreme value near r3. Then, as the rotation speed increases further, the torque fluctuation shown by the broken line becomes dominant, and the magnitude of the torque fluctuation also 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 provide a positive torque to the crankshaft at the operation start timing θ1, and the power generation function is made to exhibit a reverse torque to the crankshaft. The operation start speed and timing θ, which give the rotational speed r, are controlled to be changed around the rotational speed r. 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 timings θ1, θ1 of the electric function and power generation function are determined.
are the values θs1 and θ depending on the torque fluctuation at low speed, respectively.
□, and when the rotation speed exceeds r, the operation start timings θ8, θ are set to values θs2, θ, 2 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 θ1 for demonstrating the electric function and power generation function,
θt1 are set as functions fs(r, v), f, (r, ■) of the engine speed r and the intake negative pressure V, respectively.

This functional characteristic varies depending on the type of engine, but roughly speaking, the operating period θ is on the low and high rotation side with the rotation speed r as a boundary.
, S, θ, 1 are set to be longer, and the operating period θ and θt1 are set to be longer as the load increases. Then, in light of the torque fluctuation characteristics corresponding to the rotation speed r at that time, the crank angle θ at that time is within the time range in which the stator and rotor structures should perform the electric function, that is, from the start of operation θ3 to the end of operation θ8 + θ2. ．． If it is in the range up to , the drive circuit 25 puts the connection terminal group 25a into a connected state via the timing control circuit 37. Further, the drive circuit 26 via the timing control circuit 38
The contact 26a is opened. As a result, the stator coil 7 and the electric rotor coil 8 are energized and the electric function is performed. That is, positive 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. Further, when the crank angle θ is within the time range in which the power generation function should be exhibited, that is, within the range from the start of operation θ1 to the end of operation θ1+θ, the connection terminal group 25b of the drive circuit 25 is in the connected state, Contact 26a of drive circuit 26 closes. As a result, the power generation rotor coil 9 is energized,
Power generation function is demonstrated. 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 exerted for the operating period θ, S at the timing shown in FIG. 10C, and provides the crankshaft 1 with a positive torque having the characteristics shown in FIG. 10D. Further, the power generation function is activated during the operation period θ5. The crankshaft 1 exerts a reverse torque with characteristics as shown in Fig. 10D.
give to As a result, the positive and negative additional torques shown in FIG. 10D are appropriately added to the torque fluctuation shown by the solid line characteristic in FIG. 10A as a whole. As a result, the amount of fluctuation is corrected as shown by the dashed line in FIG. 10A, and the amount of fluctuation is reduced.

In this example, the current to the electric rotor coil 8 is detected by the ammeter 42, and when the crank angle θ is outside the range in which the electric function should be exerted when torque fluctuation control is performed. , that is, when 0 x θ x θ, the switching circuit 27 cuts off the current to the electric coil 8 if the electric coil 8 is in the energized state.

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.

Further, the torque fluctuation suppressing device of the present invention can be applied to engines having different numbers of cylinders without requiring any modification. Furthermore, although a relay circuit is usually used to perform switching control as in the present invention, the present invention is configured so that the electric state does not continue beyond a predetermined time even if the relay circuit malfunctions. Therefore, there is no problem of over-discharging of the battery due to the above-mentioned malfunction.

[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 torque fluctuation of the crankshaft, FIG. 10B is a graph showing when to exert the power generation function, and FIG. 10C is a graph to show the electric function. A graph showing the timing, FIG. 10D, is a graph showing the additional torque applied to the crankshaft by the electric power generator, and FIG. 11 is a graph showing the relationship between the amount of torque fluctuation and the change in engine speed. 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, 10...
・Magnetic material, 20...control circuit, 22...battery,
39...controller. Figure 4 Figure 7 Figure 5

Claims (1)

[Claims] An electric power generation 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 generation device, and a relatively high torque of the torque fluctuation characteristics of the crankshaft. The switching means is actuated such that the power generation function is exerted in response to the low torque period and reverse torque is applied to the crankshaft, and the electric power function is exerted in response to the low torque period and positive torque is applied to the crankshaft. An engine torque fluctuation suppressing device comprising a timing control means for controlling timing, and an energization stopping means for cutting off current when the energization state in which an electric function is exerted continues beyond a predetermined time. .