JPH0617696B2 - Control device for magnetic powder type electromagnetic clutch for vehicle - Google Patents

Description

TECHNICAL FIELD The present invention relates to a control device for a magnetic powder electromagnetic clutch for a vehicle, and more particularly to a control technique for adjusting a transmission torque in an engaging process of the electromagnetic clutch.

2. Description of the Related Art There is a magnetic powder type electromagnetic clutch as a kind of clutch inserted in a power transmission path from a vehicle engine to a driving force. In such a clutch, since a torque having a magnitude corresponding to the exciting current supplied to the exciting coil can be transmitted, the clutch is characterized by being easily controlled by a control means such as a microcomputer. That is, generally, in the magnetic powder type electromagnetic clutch, as shown in the transfer characteristic of FIG. 7, the exciting current and the transfer torque are in a substantially proportional relationship.
Rotation of the engine using the control equation shown in the equation V = Kc (Ne-Nidl) (1) where Nidl is the engine rotation speed during idling. Kc is a constant.

By increasing the exciting voltage applied to the exciting coil according to the speed, the magnetic powder electromagnetic clutch is smoothly engaged when the vehicle starts.

Problems to be Solved by the Invention However, when an exciting voltage is applied to the exciting coil, there is a delay in the rise of the transmission torque in the electromagnetic clutch. That is, even if an exciting voltage is applied to the exciting coil, the rising of the exciting current is delayed due to the influence of the inductance of the exciting coil, and the rising of the exciting current causes a delay in the rising of the transfer torque. is there. Therefore, in the process of engaging the magnetic powder type electromagnetic clutch when the vehicle starts, the exciting current always follows the increase in the engine speed with a delay, so that a sufficient response to the accelerator operation amount can be obtained. As a result, sufficient drivability was not obtained. Further, since the driver further increases the accelerator operation amount by obtaining a desired acceleration or vehicle speed, the meat rotation speed of the magnetic particle type electromagnetic clutch is unnecessarily increased at the time of vehicle start, and sufficient fuel consumption efficiency cannot be obtained. However, there is an inconvenience that the engine noise increases when the vehicle starts.

Further, for example, as shown by the solid line in FIG. 8, the engine rotation speed Ne initially increases more than necessary due to the rising delay of the exciting current to accelerate the vehicle, and then the engine rotation speed starts to decrease due to the inertia load of the vehicle. Since the exciting current is delayed, a hunting phenomenon occurs in which the engine rotation speed decreases more than necessary, which may impair drivability.

Means for Solving the Problems The present invention has been made in view of the above circumstances, and the gist of the present invention is to insert an exciting coil in a power transmission path from an engine of a vehicle to driving wheels. In a magnetic powder type electromagnetic clutch for a vehicle that transmits a torque having a magnitude corresponding to an exciting current supplied to, an exciting voltage applied to the exciting coil is increased at a predetermined increase rate in accordance with an increase in the rotation speed of the engine. Thus, in the control device for adjusting the transmission torque in the engagement process of the electromagnetic clutch, (1) basic excitation voltage determination for sequentially determining the basic excitation voltage based on the rotational speed of the engine from the relationship obtained in advance. Means, and (2) by correcting the basic excitation voltage based on a correction amount for compensating for a delay in the rising response of the transmission torque of the electromagnetic clutch. And an excitation voltage determining means for determining the excitation voltage.

In this way, the basic excitation voltage obtained based on the engine rotation speed is corrected based on the correction amount for compensating for the delay in the rising response of the transmission torque of the electromagnetic clutch. Since the exciting voltage is determined by this, the delay in the rising response of the electromagnetic clutch transmission torque is compensated by the correction. Therefore, the decrease in drivability due to the delay characteristic of the electromagnetic clutch is eliminated, and the fuel consumption efficiency and the engine noise when the vehicle starts are suitably improved.

The correction may be performed by adding a predetermined fixed correction amount or a correction amount determined based on an actual output of the engine from a relationship obtained in advance to the basic excitation voltage. , The correction amount determined based on the actual required output of the engine or the correction amount determined based on the increase rate of the rotation speed of the engine or the increase rate of the excitation voltage is added to the basic excitation voltage. You may be broken.

Further, it is desirable that the correction amount when the basic excitation voltage is corrected as described above is decreased with the passage of time in accordance with the relationship obtained in advance.

Embodiment Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.

In FIG. 1, the crankshaft 12 of the engine 10
An input shaft 18 of a transmission 16 such as a belt type continuously variable transmission or a stepped transmission is connected to the magnetic powder type electromagnetic clutch 14. Crank shaft 12 and input shaft 18
Correspond to the input shaft and the output shaft of the magnetic powder type electromagnetic clutch 14.

As shown in detail in FIG. 2, the magnetic powder type electromagnetic clutch 14
Has a flywheel 22 fixed to the shaft end of the crankshaft 12 and having an annular yoke 20. An annular excitation coil 24 is embedded in the center of the yoke 20 in its cross section, and an excitation voltage is supplied to the excitation coil 24 from a power supply brush (not shown) via a slip ring 26 that rotates together with the yoke 20. It has become. Inside the yoke 20, a rotor 28, which is a driven side rotating body, is rotatably supported by a first labyrinth member 32 via a bearing 30. This first
The labyrinth member 32 has an annular projection 3 that seals magnetic particles 34 to be filled by a magnetic force in a gap formed between the inner peripheral surface of the yoke 20 and the outer peripheral surface of the rotor 28.
6 is fixed. The annular protrusion 36 and the second labyrinth member 38 provided on the other end surface of the yoke 20 form an annular space that is substantially sealed, and the magnetic powder 34 is prevented from leaking out. In the electromagnetic clutch 14, when a magnetic field is formed according to the exciting current flowing through the exciting coil 24, the magnetic particles 34 are filled in the gap between the yoke 20 and the rotor 28, and the crankshaft 12 has the characteristics shown in FIG. Is transmitted to the input shaft 18. The input shaft 18 has a hub 4 at its shaft end.
0 is spline-fitted, and the hub 40 is connected to the rotor 28 via a damper 42 for absorbing an engagement shock.

Returning to FIG. 1, the drive shaft 48 of the vehicle is connected to the output shaft 44 of the transmission 16 via the final reduction gear 46, and the rotation of the engine 10 causes the magnetic powder electromagnetic clutch 14 and the transmission 1 to rotate.
6. The final reduction gear 46 is transmitted to the drive wheels 48.

A throttle sensor 52 for detecting the opening of the throttle valve 50 is provided in the intake pipe of the engine 10, and a signal indicating the throttle valve opening θ is A / D converted by a microcomputer (for example, a so-called ECU) 54. Vessel 56
Is supplied to. Further, a signal corresponding to an ignition pulse for the engine 10 is output from an igniter 58 attached to the engine 10 to the I / F of the microcomputer 54.
It is supplied to the circuit 60. A rotation sensor 62 is provided near the input shaft 18 of the transmission 16 that constitutes the output shaft of the electromagnetic clutch 14, and a pulse signal having a frequency corresponding to the rotation speed thereof is supplied to the I / F circuit 60. It Similarly, a rotation sensor 64 is provided near the output shaft 44 of the transmission 16, and a pulse signal having a frequency corresponding to the rotation speed of the output shaft 44, that is, the vehicle speed V is supplied to the I / F circuit 60. It That is, in the present embodiment, the throttle sensor 52 and the A / D converter 56 are the engine required output determining means, the igniter 58 and the I / F circuit 60 are the engine rotation speed detecting means, and the rotation sensor 62 and the rotation sensor 64 are electromagnetic respectively. It constitutes an output shaft rotation speed detecting means and a vehicle speed detecting means of the clutch 14.

The microcomputer 54 includes a CPU 66 and a ROM 6
8, including the RAM 70, the CPU executes signal processing according to a program stored in advance in the ROM 68 while utilizing the temporary storage function of the RAM 70, and supplies a control signal to the amplifier 74 via the D / A converter 72. The amplifier 74 applies the exciting voltage represented by the control signal to the exciting coil 24 by amplifying the control signal with a constant amplification factor. When an exciting voltage is applied to the exciting coil 24, an exciting current Ic1 corresponding to the winding resistance is passed. Here, the RO
In M68, the control formula shown in the formula (1) or a data map representing the control formula is stored, and the data map shown in FIG. 3 and the like are stored in advance.

The operation of this embodiment will be described below with reference to the flowchart of FIG.

First, step S1 is executed to execute the igniter 58,
The ignition cycle te in the igniter 58, the rotation cycle ti of the input shaft 18 of the transmission 16 and the rotation cycle to of the output shaft 44 of the transmission 16 are read based on the signals from the rotation sensor 62 and the rotation sensor 64, and the throttle sensor The voltage vθ corresponding to the throttle valve opening θ is read based on the signal from 52. Then, step S2 is executed, and based on the data read in step S1, the engine rotation speed Ne, the rotation speed Ni of the input shaft 18, the vehicle speed V, and the throttle valve opening θ are expressed by equations (2) and (3). ,(Four)
The output torque Te of the engine 10 is calculated from the equations (5) and (5), and is calculated from the data map shown in FIG. 3, and the output torque Te is used to correct the rising delay of the electromagnetic clutch 14. The amount Δv is
It is calculated according to equation (6).

Ne (rpm) = (1 / te) ・ (180 ° / 360 °) ・ 60sec… (2) Ni (rpm) ＝ (1 / ti) ・ (360 ° / 360 °) ・ 60sec… (3) v ( km) = No ・ (1 / D) ・ 2πr ・ 60min ・ (1 / 1000m) ... (4) However, No = (1 / to) ・ (360 ° / 360 °) ・ 60sec, No: Output shaft Rotation speed of 44, D: Final reducer 46
Reduction ratio, r: radius of the drive shaft 48.

θ (%) = (vθ−vidl) / (vw−vidl) (5) where vidl is the detection voltage when idling, and vw is the detection voltage when fully opened.

Δv = Kf · Te (6) However, Kf is a constant.

That is, the coordinate value Yθ (= θ / θy, where θy is the unit lattice width) of the actual θ calculated from the fact that the θ axis and the Ne axis are equally taken in the data map of FIG. Calculated actual Ne coordinate value Xn
(= Ne / Nx: Nx is the unit lattice width) is calculated. next,
The data of the points a, b, c, d closest to the coordinate point defined by these coordinate values (Yθ, Xn) are extracted. Then, the values after the decimal point of the coordinate axes Yθ, Xn ΔYθ, ΔX
The engine torque Te is obtained by interpolation calculation using n. That is, the coordinate value of the point e in the Ne axis direction is obtained from the data of the points a and b based on the equation (7),
From the data of the point and the point d, the coordinate value of the point f in the Ne axis direction is obtained according to the equation (8). Then, the coordinate values of the points e and f in the Te axis direction are obtained by the same calculation. In addition, the coordinate value of Te ^* point in the θ-axis direction is determined according to the equation (9), and the coordinate value of Te ^* point in the Te-axis direction is determined from the coordinate value and the data obtained at points e and f as described above. The difference is calculated as The obtained coordinate value is the actual output torque Te. Then, the correction amount ΔV is calculated by substituting the output torque Te thus obtained into the above equation (6).

e = (b−a) · ΔXn + a ... (7) f = (d−c) · ΔXn + c ... (8) Te ^* = (f−e) · ΔYθ + e ... (9) In step S3, the vehicle speed V is predetermined. It is determined whether or not it is larger than the predetermined small value Vl that is set, and if it is not larger, the clutch disengagement control of step S4 and thereafter is executed. The predetermined constant value Vl is an extremely small vehicle speed for determination of control switching that does not require clutch control, and is set to prevent fluttering near that vehicle speed. In step S4, the flag Fa is set to zero, and then step S5 is executed,
The throttle opening θ is a predetermined small value θ ₀
Is less than or equal to. This step S5 is for determining whether the engine 10 is in the idle state. When the throttle valve opening θ is larger than the constant value θ ₀ and not in the idle state, step S6 is skipped, but when the engine 10 is in the idle state and the throttle valve opening θ is smaller than θ _0. The actual engine speed Ne is executed after step S6 is executed.
Is set as the idle rotation speed Nidl, and the correction amount Δv
Is zero. Next, step S7 is executed to calculate the control voltage V, and the calculated control voltage v is output in step S8. However, in the case of the clutch disengagement control like this time, the correction amount Δv becomes
Since the actual rotation speed Ne is set to zero and the actual rotation speed Ne is set to the idle rotation speed Nidl, the calculated value of the control formula shown in the formula (10) is set to zero and the electromagnetic clutch 14 is disengaged. It

v = Kc (Ne-Nidl) + Δv (10) where Kc (Ne-Nidl) is the basic excitation voltage vo and Kc is a constant.

When the vehicle is traveling, it is determined in step S3 that the vehicle speed V is higher than Vl, so step S9 is executed to determine whether the flag Fa is zero. This flag Fa is for judging whether or not it is in the half-clutch state. When the content of the flag Fa is not zero, step S10 is executed and the coupling control is executed. That is, the control voltage v is set to the maximum value vmax and the content of the flag Fa is set to 1. However, when it is determined in step S9 that the content of the flag Fa is zero, step S11 is executed to determine whether the vehicle speed V is higher than a predetermined constant value Vh. This constant value Vh is a vehicle speed for determining whether or not the condition for shifting to the joint control is satisfied, and when the actual vehicle speed V exceeds the vehicle speed Vh, step S12 and subsequent steps prior to the joint control are executed. However, in the state where the vehicle speed Vh is not reached, it is not appropriate to perform the coupling control, and thus step S12 is skipped. In step S12, the engine 10
Rotation speed Ne of the crankshaft 12 and the input shaft 18
It is determined whether or not the difference between the output speed of the electromagnetic clutch 14 and the rotation speed Ni is larger than a predetermined constant value Nα. If it is large, it means that the rotation difference between the flywheel 22 of the electromagnetic clutch 14 and the rotor 28 is large. Therefore, step S7 for half-clutch (engagement) control is executed, and the control voltage v becomes (10 ) It is calculated according to the formula. That is, in step S7, the basic excitation voltage vo {= Kc (Ne-Nidl)} is first obtained, and the control amount v is obtained by adding the correction amount Δv obtained in step S2 to the basic excitation voltage vo. Is calculated. That is, in this embodiment, in step S7 for executing the calculation of the equation (10), the part for obtaining the first term on the right side of the equation (10) is the basic excitation voltage determining means, and the part on the right side of the equation (10) is The portion where the first term and the second term are added corresponds to the excitation voltage determining means, and the second term thereof corresponds to the correction amount. Then, step S8 is executed, the control voltage v obtained in step S7 is output, and the exciting voltage corresponding to the control voltage v is applied to the exciting coil 24.

In the half-clutch state such as when the vehicle starts, as described above, the control voltage v is obtained by adding the correction amount Δv to the basic excitation voltage, and the correction amount Δv is the transfer torque rise of the electromagnetic clutch 14. Since it is determined based on the output torque Te of the engine 10 from the relational expression (6) obtained in advance to correct the delay, the correction amount Δv corresponding to the delay of the rise of the transmission torque of the electromagnetic clutch 14 is calculated as follows. Therefore, since the basic exciting voltage vo is applied, the exciting current is passed through the exciting coil 24 as if the delay of the electromagnetic clutch 14 does not exist. The broken line in FIG. 8 shows this state. That is,
The feedforward control is performed in which a delay of the electromagnetic clutch 14 is predicted and a correction amount Δv corresponding to the delay is given in advance. As a result, in the half-clutch control such as when the vehicle starts, a decrease in drivability due to the delay characteristic of the electromagnetic clutch 14 and an increase in engine rotation speed accompanying an increase in accelerator operation to cover the drivability, The reduction of the fuel consumption efficiency, the noise of the engine 10, the hunting of the rotation speed of the engine 10, etc. are completely eliminated. Incidentally, step S2 in the flowchart of FIG.
A step (not shown) similar to step S5 is interposed between steps S3 and S3, and when it is determined that the throttle valve opening θ has been operated, step S3 is skipped and the vehicle can be started to zero. -ing

Next, another embodiment of the present invention will be described. In the following description, the same parts as those in the above-described embodiment will be designated by the same reference numerals and the description thereof will be omitted.

The correction amount Δv used to eliminate the delay in the rise of the transmission torque of the electromagnetic clutch 14 may be made smaller with the lapse of time from the operation of the throttle valve.
That is, as shown in the flowchart of FIG. 5, the change rate of the throttle valve opening is obtained in step S2. For example, from the previous throttle valve opening θ _n-1 and the throttle valve opening θ _n in this control cycle, (1
1) Formula = (θ _n-1 −θ _n ) / tc (11) However, tc is calculated according to the cycle of the control cycle. Then, steps S13 to S15 are executed prior to step S3. That is, in step S13, it is determined whether or not the changing speed of the throttle valve opening is larger than a predetermined constant value α,
If it is larger, it is judged that the throttle valve has been operated and the timer T is reset, but if it is not larger, it is judged that the throttle valve opening is maintained and step S14 is executed to set the content of the timer T to 1 And count. In step S7, the correction amount Δv is decreased with time according to the equation (12), and according to the equation (12), Δv = Kf · | Te | −K · T (12) where Kf and K are constants, The control amount v is calculated by substituting the correction amount Δv calculated by the elapsed time from the operation of the throttle valve into the control equation shown in the equation (10). That is, in the present embodiment, of the two equations described in the upper and lower rows within the frame of step S7 in FIG. 5, the portion for obtaining the first term on the right side of the lower equation (equation (10)) is basically The excitation voltage determining means corresponds to the excitation voltage determining means, and the portion for adding the first term and the second term on the right side of the lower equation corresponds to the excitation voltage determining means. The portions for calculating the equation (that is, the equation (12) above) correspond to the correction amounts, respectively. Thus, according to the present embodiment, the electromagnetic clutch 1
As the delay of the rising response of 4 is eliminated with the passage of time, the correction amount Δv is also reduced with the passage of time, so that an unnecessary amount of correction (feedforward) is prevented and optimum feedforward control is performed. There are advantages that can be obtained.

Although the embodiment of the present invention has been described above with reference to the drawings, the present invention can be applied to other aspects.

For example, in the above-described embodiment, the correction amount Δv may be obtained from the function of the throttle valve opening θ shown in the equation (13) or the data map shown in FIG. At this time,
Since the throttle valve opening θ indicates the required output of the engine, other amounts indicating the required output of the engine, for example, the accelerator pedal operation amount, the fuel injection amount, the intake pipe negative pressure, or the like may be used. .

Δv = Kθ · f (θ) (13) Further, in step S2 of the above-described embodiment, the output torque Te of the engine 10 is calculated from the data map, but it is provided on the crankshaft 12 or the like of the engine 10. It may be detected by a torque sensor.

Further, since the magnitude of the delay in the electromagnetic clutch 14 corresponds to the rate of increase of the engine speed or the rate of increase of the control voltage v (excitation voltage), the correction amount Δv is the rate of increase e of the engine speed or the control voltage. It may be calculated from the relationship obtained in advance based on the rate of change of. However, even if the correction amount Δv is a predetermined constant value, a temporary effect can be obtained.

The above description is merely one embodiment of the present invention, and the present invention can be variously modified without departing from the spirit thereof.

[Brief description of drawings]

FIG. 1 is a block diagram showing the configuration of a control device which is an embodiment of the present invention. FIG. 2 is a sectional view showing the structure of the magnetic powder type electromagnetic clutch used in FIG. FIG. 3 shows an example of data stored in advance in the apparatus shown in FIG. FIG. 4 is a flow chart for explaining the operation of the embodiment shown in FIG. FIG. 5 is a flow chart for explaining the operation of the control device of another embodiment of the present invention. FIG. 6 shows an example of a previously obtained relationship used to obtain the correction amount. FIG. 7 is a diagram showing general transmission characteristics of the electromagnetic clutch shown in FIG. FIG. 8 is a time chart showing the operating state of the clutch in the apparatus of FIG. 1 in comparison with the conventional case. 10: Engine, 14: Magnetic powder type electromagnetic clutch 24: Excitation coil

Front Page Continuation (72) Inventor Takashi Hayashi 1 Toyota-cho, Toyota-shi, Aichi Prefecture Toyota Motor Corporation (56) References JP-A-57-87722 (JP, A)

Claims (5)

[Claims] 1. A magnetic powder electromagnetic clutch for a vehicle, which is inserted in a power transmission path from an engine of a vehicle to a drive wheel and transmits a torque having a magnitude corresponding to an exciting current supplied to an exciting coil, wherein A control device that adjusts the transmission torque in the engagement process of the electromagnetic clutch by increasing the excitation voltage applied to the excitation coil at a predetermined increase rate according to the increase in the rotation speed, the relationship being determined in advance. From the basic excitation voltage determining means for sequentially determining the basic excitation voltage based on the rotational speed of the engine, and correcting the basic excitation voltage based on a correction amount for compensating for the delay in the rising response of the transmission torque of the electromagnetic clutch. And a magnetizing voltage determining means for determining the magnetizing voltage. 2. The control of a magnetic powder electromagnetic clutch for a vehicle according to claim 1, wherein the correction is performed by adding a predetermined fixed correction amount to the basic excitation voltage. apparatus. 3. The correction is performed by adding a correction amount, which is determined based on an actual output of the engine from a relationship obtained in advance, to the basic excitation voltage. The control device for a magnetic powder type electromagnetic clutch for a vehicle according to the item. 4. The correction is performed by adding a correction amount determined based on an actual required output of the engine from a relationship obtained in advance to the basic excitation voltage. The control device for a magnetic powder electromagnetic clutch for a vehicle according to item 1. 5. The control device for a magnetic particle type electromagnetic clutch for a vehicle according to claim 2, wherein the correction amount is decreased with time according to a relationship obtained in advance.