JP2002106378A - Hybrid drive method for continuously variable transmission - Google Patents

Abstract

PROBLEM TO BE SOLVED: To use the output power from an engine with a high energy efficiency in a vehicle using a continuously variable transmission having a generator interlocked to an input shaft. SOLUTION: A control for performing the traveling speed control of the vehicle by the speed ratio control or torque converting control of the continuously variable transmission as the engine is operated at a fixed working point with high fuel consumption rate by the generator and a vehicle traveling control for charging the power by the generation of the generator in a battery and reusing the charged power for the traveling power of the vehicle are alternately performed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hybrid drive method of a continuously variable transmission for further reducing fuel consumption per mileage in an automobile using an engine.

[0002]

2. Description of the Related Art FIG. 5 is a system diagram showing a conventional drive device equipped with a continuously variable transmission.
The output shaft 1a of the engine 1 in FIG. 5 is driven by a drive wheel via a continuously variable transmission 20 including a clutch 20A such as a torque converter and a transmission 2B, an output shaft 2b, and a differential gear (hereinafter simply referred to as a differential) 3. 3a, 3b
It is linked to.

Generally, a speed ratio e = n2 / n1 (reciprocal of a normal speed reduction ratio) obtained by dividing a rotation speed n2 of an output shaft 2b by a rotation speed n1 of an input shaft 1a by an external operation or a command signal. A continuously variable transmission that can be controlled steplessly cannot make its speed ratio e zero. That is, the ideal speed ratio e = 0 means that the ideal continuously variable transmission converts the output torque from the engine 1 to infinity and outputs it to the output shaft 2b. Cannot do such an infinite transformation.

[0004] On the other hand, in a normal internal combustion engine, there is a minimum rotational speed (idling rotational speed) for maintaining its operation. On the other hand, the vehicle driven by the internal combustion engine must start from a state where the vehicle speed is zero. This means that the speed ratio of the continuously variable transmission must be shifted from zero by some means in order to start the vehicle from zero speed when the internal combustion engine is in a finite rotational speed state. I have.

In general, as a means, the continuously variable transmission is provided with a clutch 20A, for example, a fluid torque converter, an electromagnetic clutch, etc., in series with the transmission 2B, as shown in FIG.

[0006] The continuously variable transmission 20 is not only a stepless transmission of a conventional stepped transmission, but also has an engine 1.
Is operated in the best fuel consumption state by the shift control. Here, the characteristics of the engine 1 will be described below.

Engines such as gasoline engines generally have the properties shown in FIG. In FIG. 4, the vertical axis Te indicates the output torque of the engine, and the horizontal axis ne indicates the rotation speed of the engine.

The symbols in FIG. 4 are as follows. θ: Throttle opening degree in the engine or constant torque characteristics of fuel supply to the engine (hereinafter referred to as fuel supply amount), θm indicates torque characteristics at the time of maximum fuel supply, and constant value of fuel supply amount θ Becomes smaller,
The torque characteristics are as shown in θb, θa, θc.

Λ: A fuel consumption rate per output power per unit time (hereinafter simply referred to as a fuel efficiency rate).
“a” indicates the minimum fuel efficiency, and the fuel efficiency decreases as the curve of the constant fuel efficiency shown by the one-dot broken line moves away from the curve of λa like λb.

P: Constant power characteristics, Pb, P
The power decreases in the order of a, Pc, and Pg. Eh, El: The economic fuel efficiency characteristics in which the engine fuel efficiency is minimized when the output power of the engine is constant (for example, for each of Pb, Pa, and Pc).

As can be understood from the description of the reference numerals in FIG. 4, in order to obtain the minimum fuel efficiency for each power P, the engine may be operated as follows.

The output power of the engine is represented by P (eg, Pb, P
a, Pc), first, the fuel supply amount θ is set according to an instruction from the accelerator pedal (for example, θ
b, θa, θc).

Next, for each setting of the fuel supply amount θ,
The load torque Te of the engine is controlled by controlling the speed ratio of the continuously variable transmission 20. The control is based on a specified load corresponding to the intersection of the set fuel supply amount θ and the economical fuel efficiency characteristic Eh or El, for example, if the fuel supply amount is set to θa, the specified rotational speed of the engine 1 Is nea, or the specified torque is T
The load on the engine may be controlled by controlling the speed ratio of the continuously variable transmission 20 so as to achieve ea.

If the operating point of the engine 1 controlled in this way is, for example, point a in FIG. 4, the output power of the engine 1 in that case becomes Pa from FIG. The output power of Pa is output to the output shaft 2 via the continuously variable transmission 20.
b to the driving wheels 3a and 3b, and the output power Pa becomes a running speed balanced with the running resistance power including the acceleration power of the vehicle.

Of the fuel economy characteristics shown in FIG.
Although the low output power portion of l is the optimum fuel efficiency while the fuel supply amount to the engine 1 is constant, the fuel efficiency is lower than the fuel efficiency of the portion of the economic fuel efficiency characteristic Eh in the high output power portion. On the other hand, the fuel efficiency becomes considerably lower, and particularly when the engine 1 is idling, the fuel efficiency becomes zero.

In view of the above, recently, when the vehicle is running using the economical fuel efficiency characteristic Eh under a high load condition, part of the power is converted into electric power and stored in the storage battery, and the fuel efficiency is reduced. In the case of traveling corresponding to the power of the El part of 4, there is a method of traveling with the charged power.

That is, the engine output energy in a portion where the fuel efficiency of the engine 1 is good is temporarily stored in the battery, and when the power Pc or less shown in FIG. 4 is required, the stored energy is used as vehicle running energy. As a result, fuel economy per vehicle mileage is improved.

[0018]

Conventionally, in the case where the vehicle is driven with a power of a level equal to or lower than the power Pc in FIG. 4, the mechanical power from the engine 1 is converted into electric energy, and the conversion is performed. The converted electric energy is converted into mechanical power again to drive the drive wheels 3a and 3b.

In this case, conversion from the form of mechanical power to another form of electric power or vice versa always incurs a loss, and there is still much waste as a method of using energy from the engine 1.

According to the present invention, even if the power required to drive the vehicle is less than the power Pc shown in FIG. 4, the power transmission component is increased while maintaining the mechanical power with the highest power transmission efficiency as much as possible. In addition, the hybrid drive method of the continuously variable transmission further reduces the fuel consumption per vehicle mileage by maintaining the high fuel efficiency of the engine 1 for charging by converting the power of the engine 1 into electric power. Is to provide.

[0021]

SUMMARY OF THE INVENTION The present invention provides a continuously variable transmission (2) provided between an output of an engine (1) and driving wheels.
, A generator (G) that also performs a motor function is linked to the input shaft (2a) of the transmission unit (2B), and the power generated by the generator is charged, and the generated power causes the generator to operate as a motor. A speed ratio e = n2 / n obtained by dividing the rotation speed n2 of the output shaft (2b) by the rotation speed n1 of the input shaft.
1 is in the control of operating.

The control unit (4A) stores, for each given constant fuel supply amount (θ) to the engine, a specified load on the engine that maximizes the fuel efficiency of the engine as data. .

When the required power for the driving wheels is less than a predetermined power and the amount of stored power in the battery is less than a predetermined value, the following control is performed.

The control device includes: 1: setting the fuel supply amount to a constant value corresponding to the engine outputting the predetermined power; and 2: setting the power level generated by the generator to the constant value. Controlling the load on the engine to the specified load of the engine with respect to the fuel supply amount set to a value; and 3: controlling the speed ratio in conjunction with the command value of the required power. It has become something.

[0025]

BEST MODE FOR CARRYING OUT THE INVENTION

FIG. 1 is a system diagram showing a hybrid drive unit of a continuously variable transmission 2 according to the present invention. The drive shaft 1a from the engine 1 is interlocked with the carrier 2d of the differential gear 2A, and the planetary gear 2e supported by the carrier 2d meshes with the outer circumference of the sun gear 2c and the inner circumference of the ring gear 2f, respectively.

The generator G comprises a stator S and a rotor R, and a clutch C1 is provided between the rotor R and the sun gear 2c.
And a clutch C2 is provided between the rotor R and the ring gear 2f. Input shaft 2a in transmission section 2B
Is linked to driving wheels (not shown) via the transmission 2B and the output shaft 2b.

The wiring 4a is connected to the battery 4 via the control device 4A.
Connected to The transmission 2B in FIG.
5 is the same as the transmission section 2B. Also, the engine 1
It has the same characteristics as FIG. Hereinafter, the operation of FIG. 1 will be described.

In the present invention, the vehicle travels in accordance with an instruction value of required power from an accelerator pedal (not shown) operated by the driver. In this case, the command value of the required power may be any one of the traveling speed, the driving torque of the driving wheels, or the value of the power.

Increasing or decreasing the required value of the required power means increasing or decreasing the traveling speed or the driving torque of the driving wheels. Increasing or decreasing the traveling speed involves increasing or decreasing the driving power of the driving wheels from the current traveling state. It is to be. or,
Increasing or decreasing the drive torque of the drive wheels also means increasing or decreasing the drive power of the drive wheels from the current running state.

Therefore, the specific signal of the accelerator pedal instructing the required power may be an instruction to increase or decrease any of the traveling speed to the driving wheels, the driving torque or the power. For this reason, the expression “required power” is used to represent that the instruction from the accelerator pedal in the present invention may be any one of the traveling speed, the driving torque, and the power.

The running speed of the drive wheels is proportional to the rotation speed of the output shaft 2b, and the traction force of the drive wheels is proportional to the drive torque of the output shaft 2b. The traction force will be described using the rotational speed and output torque of the output shaft 2b as a representative.

Before explaining the operation of FIG. 1, FIG. 2 will be described. In FIG. 2, the vertical axis T2 indicates the driving torque of the output shaft 2b, and the horizontal axis n2 indicates the rotation speed of the output shaft 2b.

The characteristic Pb or Pc in FIG. 2 indicates that the drive shaft 1a of the engine 1 is directly connected to the input shaft 2a of the transmission 2B in FIG. 1, and the power transmission efficiency of the continuously variable transmission 2 is 100%. In this case, the values correspond to the values at which the engine 1 outputs a constant power at point b or point c in FIG. 4, respectively.

That is, the output power P of the engine 1
b or Pc is output to the output shaft 2b without any power loss as it is, the output is the characteristic P in FIG.
b or Pc.

In FIG. 4, for example, if the operation of the engine 1 is operating at the point c, the engine 1 is operating at a constant rotational speed nec and a constant torque Tec. In that case, the output power Pc of the engine 1
Is proportional to the product of the torque Tec and the rotation speed nec. The output power of the output shaft 2b is also proportional to the product of the torque T2 and the rotation speed n2 of the output shaft 2b. When all the output power of the engine 1 is output to the output shaft 2b without loss, Tec × nec = T2 × n2 or n2 / nec = Tec / T2 (1)

Here, since the drive shaft 1a and the input shaft 2a are in a directly connected state, nec = n1. Therefore, the expression (1) is as follows: n2 / nec = n2 / n1 = e = Tec / T2 (2) From the expression (2), n2 = e × nec (3) and T2 = Tec / e (4) obtain.

By using the speed ratio e in the above equations (3) and (4) as a variable and substituting the value of the e specifically, the characteristic in FIG. 2 when the output power of the engine 1 is Pc. Pc can be determined. Similarly, in equations (3) and (4), nec is neb (FIG. 4),
By replacing the operation at the point b in the engine 1 with Tec being Teb, the characteristic Pb in FIG. 2, that is, the characteristic corresponding to the case where the output power Pb in the engine 1 is constant can be obtained.

In the characteristic Pc shown in FIG. 2, the operating point when the minimum speed ratio e = emin corresponds to the point co. As the speed ratio e is increased, c1 and c are successively increased.
2, f, c4. Similarly, in the characteristic Pb in FIG. 2, the operating point when the minimum speed ratio e = emin corresponds to the bo point, and as the speed ratio is sequentially increased,
b1, b2, b3, and b4.

In FIG. 2, the characteristic of the two-dot broken line connecting the operating point co to the operating point bo is that the engine 1 moves from the operating point c in FIG. 4 while the speed ratio e is kept at the minimum constant value e = emin. This shows the characteristics operating on the economical fuel efficiency characteristic Eh up to the operating point b.

Similarly, when the engine 1 operates on the fuel economy characteristic Eh shown in FIG. 4, the characteristic of the power output to the output shaft 2b is that the speed ratios are e = e1, e = e2, e =
In the case where e3 or e = e4 is kept constant, in FIG.
Characteristic.

The characteristic P20 in FIG. 2 indicates a characteristic corresponding to the running resistance of the vehicle when the road gradient is zero, and the characteristic P21 indicates a characteristic corresponding to a constant gradient where the road gradient is larger than zero. Is shown.

The operation of FIG. 1 will be described below using the above-described running characteristics of the vehicle (FIG. 2) and the characteristics of the engine 1 (FIG. 2).

When the vehicle is started from a stopped state and the battery 4 has a sufficient amount of stored power, the engine 1 is not operated and is started by the motor drive of the generator G and the required power is at a predetermined level. In the range below the power Pc, the vehicle runs by the motor drive of the generator G. In this case, the clutch C1 in FIG. 1 is released, the clutch C2 is engaged, and the electric motor G is driven.

The driving force by the motor drive of the electric motor G is:
Reaction force axis Ro, clutch C2, ring gear 2f, input shaft 2
a, drive wheels (not shown) are driven via the transmission 2B and the output shaft 2b. In this case, the ring gear 2f drives the sun gear 2c via the planetary gear 2e, but since the clutch C1 is in the disengaged state, the sun gear 2c idles, and the driving force of the ring gear 2f is transmitted via the carrier 2d. The engine 1 is not driven.

When the vehicle runs only with the energy of the battery 4, the motor output power of the generator G is controlled in accordance with the power demanded from the accelerator pedal, and the transmission 2B
May be controlled to a speed ratio that keeps the operation efficiency of the motor drive favorable.

In contrast to the above operation, when the vehicle starts from a stopped state and the charged amount of the battery 4 is equal to or less than a predetermined value, the vehicle runs by driving the engine 1 described below. In this case, first, both the clutches C1 and C2 are released, and the engine 1 is started.

When the engine 1 is started, the two clutches C1 and C2 are disengaged, so that the carrier 2d tries to drive the ring gear 2f and the sun gear 2c via the drive shaft 1a by the start. Since the clutch C1 is in the disengaged state, the sun gear 2c idles. Therefore, the engine 1 can be started with no load.

It should be noted that the engine 1 may be started with the generator G not loaded while the clutch C1 is engaged. Also in this case, when the engine 1 is started, the sun gear 2c is idling since the generator G has no load.

When the engine 1 is started, if the remaining capacity of the battery 4 is sufficient to start the vehicle,
The vehicle 1 may be started by the power of the battery 4 and the engine 1 may be started by the driving force immediately after the start. In this case, if the clutch C2 is also engaged in a state where the vehicle is started by the electric power of the battery 4, the driving shaft 1a and the input shaft 2a are directly connected, and the driving energy of the vehicle drives the engine 1. In that case, when the driving energy of the vehicle drives the engine 1, a shock is likely to occur,
The shock can smoothly control the torque generated on the output shaft 2b by controlling the motor operation or the power generation operation of the generator G.

In the state where the engine 1 is started in this way, the control device 4A links the instruction from the accelerator pedal to the fuel supply amount θ to the engine 1 and sets the clutch when the generator G is in the no-load state. Engage C1 and leave clutch C2 open. Further, in that case, the speed ratio e = n2 / n1 of the transmission portion 2B becomes e = emi
n is kept at the lowest speed ratio.

In this state, when the accelerator pedal is depressed, the fuel supply amount θ of the engine 1 is increased in conjunction with the depression of the accelerator pedal. The system is set to apply a load to. Here, the operation of generating a load on the engine 1 by the power generation of the generator G occurs as follows.

The differential gear 2A has a torque Tr generated on the sun gear 2c, a load torque generated on the engine 1, that is, a torque Te generated on the carrier 2d, and a ring Te according to the respective gear ratios of the sun gear 2c, the planetary gear 2e and the ring gear 2f. Each ratio with the torque T1 generated in the gear 2f, Te / T
r and T1 / Tr have a fixed relationship. Therefore, the load torque Te of the engine 1 can be controlled by controlling the torque Tr generated in the rotor R, that is, the level of power generation in the generator G.

Utilizing such a property, in the above-described power generation of the generator G, the load torque Te of the engine 1 increases with the fuel supply amount θ at that time every time the value of the fuel supply amount θ increases. The load torque may be controlled so as to correspond to the intersection of the fuel economy characteristic El in FIG. That is, this means that the operation of the engine 1 operates on the economical fuel efficiency characteristic E with good fuel efficiency. In this case, the power generation level of the generator G is controlled by controlling the rotation speed ne of the engine 1 by the fuel supply. This is the same even if control is performed so that the value becomes an intersection between the amount θ and the economic fuel efficiency characteristic E.

With this control, the output power of the engine 1 increases in accordance with the economical fuel consumption characteristic E in FIG. 4 in accordance with the depression of the accelerator pedal. This is because, as described above, the torque Tr generated in the rotor R or the torque Te of the engine 1 and the torque generated in the ring gear 2f, that is, the torque T1 generated in the input shaft 2a, have a fixed relationship. Depressed engine 1
As the torque Te increases, the torque T1 on the input shaft 2a also increases.

The torque T1 of the input shaft 2a is applied to the transmission 2B.
And the drive wheels are accelerated via the output shaft 2b. As described above, the operation of depressing the accelerator pedal to accelerate the rotation speed n1 of the input shaft 2a is performed until the rotation speed n1 of the input shaft 2a reaches a rotation speed slightly higher than the idling rotation speed of the engine 1. .

When the state is reached, the control device 4A keeps the clutch C2 engaged while keeping the clutch C1 engaged.
Are also engaged. In this state, the sun gear 2c and the ring gear 2f rotate integrally, so that the rotating shaft 1a and the input shaft 2a are directly connected. When this state is reached, the control device 4A enters the following control mode.

On the other hand, the control device 4A controls the fuel supply amount θ with respect to the engine 1 at a predetermined speed or at a speed proportional to the depression speed of the accelerator pedal, as shown in FIG.
Increase toward c. In the process of increasing the fuel supply amount θ, the generator G is caused to generate electric power, and the level control of the power generation is performed in the same manner as described above. El
Is controlled so as to be a load at the intersection with.

For example, if the current fuel supply amount θ is θ = θ
g (FIG. 4), the load on the engine 1 at that time is the torque Teg in FIG. The load may be any load at which the operating point of the engine 1 is point c. Therefore, the load control on the engine 1 by the generator G may be controlled so that the rotational speed ne of the engine 1 is ne = neg.

The control of the engine 1 by the generator G is as follows.
From the current output power Pg of the engine 1 to the generator G
Absorbs the power of dP and the power after absorption (Pg−
dP) is supplied to the input shaft 2a.
From the viewpoint of torque transmission, this means that the rotor R absorbs dT from the output torque Teg of the engine 1 and the (Teg-dT) torque is transmitted to the input shaft 2a. I have.

In addition to the control of the engine 1 by the generator G, the control device 4A simultaneously performs control to satisfy the required power to the drive wheels according to the instruction of the accelerator pedal. As described above, the required power from the accelerator pedal is an instruction value of the output level to the drive wheel or the output shaft 2b, and the expressions of the required power are the above-mentioned "power" and "torque".
Alternatively, an example in which “torque” is considered among expressions representing “speed” will be described.

The control unit 4A calculates the speed ratio e = n2 / n1 of the transmission 2B in proportion to the depression amount of the accelerator pedal.
Control.

That is, within the present minute time in the process of increasing the fuel supply amount θ toward θc, the operating point of the engine 1 is point g in FIG. Rotation speed n at 1
e is ne = neg. Therefore, as described above, if the speed ratio e is increased in accordance with the depression of the accelerator pedal within a short time in which the fuel supply amount θ can be assumed to be constant at θ = θc, the generator G
Controls the engine 1 to be maintained at a constant rotation speed neg, whereas an increase in the speed ratio in the transmission section 2B increases the rotation speed n2 of the output shaft 2b.

Here, it is assumed that the gradient of the traveling road surface on which the vehicle is currently traveling is constant at zero for convenience of explanation. The traveling has the traveling characteristic P20 in FIG. 2 as described above. That is, as the rotational speed n2 of the output shaft 2b increases as described above, the output resistance torque T2 of the output shaft 2b also increases along the traveling characteristic P20.

Then, as a result of the increase in the resistance of the output shaft 2b, the torque T1 of the input shaft 2a also increases, and the load on the engine 1 increases. Due to the increase in the load, the operation of the engine 1 shifts from the control equilibrium point g on the current fuel supply amount θg constant line to a direction in which the rotation speed n1 of the engine 1 decreases.

However, the generator G always controls the operation of the engine 1 to operate on the economical fuel consumption characteristic El.
That is, when the load on the engine 1 becomes excessive as described above, the generator G reduces the load torque dT absorbed from the output torque Te of the engine 1 to reduce the load. As a result, the operating point of the engine 1 returns on the constant fuel supply amount θg line toward the point g, and when the operating point reaches the point g, the control is balanced.

This means that, on the one hand, the generator G always controls the engine 1 on the economic fuel consumption characteristic line El, and on the other hand, the traveling speed or power of the drive wheels is increased by controlling the speed ratio e. Then, control is performed to reduce the power absorbed by the generator G by an amount corresponding to the increase in the running power.

The above-described operation of accelerating the vehicle will now be described with reference to FIG.
It is assumed that the operating point b is the point h where the traveling road surface gradient = 0.

From this state, as the required power to the output shaft 2b is increased by depressing the accelerator pedal, the absorption of the torque dT of the generator G is reduced as described above, and the torque at the input shaft 2a is correspondingly reduced. The value of T1 increases. This means that the driving torque T2 on the output shaft 2b increases via the transmission 2B. It is assumed that the new value of the increased output shaft torque T2 is T2 = T2d.

The increase in the driving torque (T2d-T2g) on the output shaft 2b becomes an acceleration torque to accelerate the output shaft 2b. Eventually, the torque T2 of the output shaft 2b
= T2d and running resistance P at running road surface gradient = 0 in FIG.
20 and the rotational speed n2 of the output shaft 2b becomes n2
= N2d.

In the state where n2 = n2d, the driving power of the output shaft 2b is Pd. That is, while the output power of the engine 1 in this state is Pg, the drive power of the output shaft 2b is Pd, which means that the generator G absorbs (Pg-Pd) power by power generation. Means that the generated power is being charged into the battery 4.

The command value of the required power in this case is T2d when the command value is a torque, n2d when the command value is a rotational speed, and Pd when the command value is a power (energy). In this state, the rotation speed ne of the engine 1 is neg and the rotation speed of the output shaft 2b is n.
2d means that the speed ratio e
Is e = n2d / neg.

As described above, at each point in the process of increasing the fuel supply amount θ, in the engine 1, the torque Tec of the engine 1 at the intersection of the fuel supply amount θ at that time and the economic fuel consumption characteristic El is obtained. (At θ = θg,
Tec = Teg) and the torque dT absorbed by the generator G
And the torque T1 on the input shaft 2a is controlled such that T1 + dT = Tec (5).

That is, for each fuel supply amount θ, in the engine 1, the output torque Te is kept constant at Te = Tec, and the speed ratio e is controlled by the required power level including acceleration and deceleration. Input shaft T
When the value of 1 changes, the absorption torque dt is controlled so that the generator G satisfies the expression (5).

Therefore, when the accelerator pedal is returned, the speed ratio is reduced by the amount corresponding to the return of the accelerator pedal, as opposed to the case where the required power is increased by depressing the accelerator pedal. The load torque T1 is reduced, and accordingly, the generator G increases the absorption torque dT to satisfy the expression (5).

In this manner, the above-described control of the attitude is performed until the fuel supply amount θ reaches θc. Eventually, the fuel supply amount θ
Reaches θ = θc, the control device 4A performs the above-described control with θ = θc constant as long as the accelerator pedal is depressed and the required power does not exceed the predetermined power Pc.

Further, when the amount of power stored in the battery 4 reaches a state where the battery 4 is charged to a predetermined value by the power generation of the generator G under the above-described control, the control device 4A performs the above-described vehicle running only with the electric power of the battery 4. When the power storage amount of the battery 4 becomes equal to or less than the predetermined value due to the switching and the traveling only by the power, the drive control of the engine 1 is repeated again.

Whether or not the required power has become equal to or greater than the predetermined power Pc can be determined by the value of the depression level of the accelerator pedal indicating the required power, but can also be determined by the following determination.

In the process where the required power increases and as a result, the power absorbed by the generator G from the drive shaft 1a decreases, the absorbed power becomes zero, that is,
When the output power Pc of the engine 1 (FIG. 4) is completely output to the output shaft 2 b as it is, this state is when the required power reaches a predetermined power.

Next, the control system in the case where the required power from the accelerator pedal falls within the range of the predetermined power Pc or more will be described. In this control state, in FIG. 1, the generator G is in a no-load state and does not generate power while both the clutches C1 and C2 are engaged.
Further, the instruction signal from the accelerator pedal is linked with the fuel supply amount θ to the engine 1.

That is, when the vehicle is running in this control state, the output power from the engine 1 is transmitted as it is to the drive wheels via the transmission portion 2B without changing the output power from the engine 1 as in the control of the normal continuously variable transmission. Be in control. Further, in this control mode, the engine 1 outputs power between a predetermined power Pc and a predetermined high power Pb, and the characteristics of the output shaft 2b are as follows.
The travel is between the characteristic Pc and the characteristic Pb in FIG.
Further, the operation of the engine 1 operates on the economic fuel consumption characteristic Eh between the predetermined power Pc and the predetermined high power Pb.

Hereinafter, the control will be described with reference to FIGS. 2 and 4. Also in this case, the value of the specified load in the engine 1 at which the fuel efficiency of the engine 1 is the best is set as data (economic fuel efficiency characteristics Eh) experimentally for each given constant fuel supply amount θ to the engine 1. Obtaining and storing the data in the control device 4A is the same as in the case where the generator G absorbs the power of the drive shaft 1a in accordance with the economic fuel consumption characteristics El described above.

In this case as well, the specified load is a factor that can specify that the engine 1 operates on the economic fuel efficiency characteristic Eh in FIG. That is,
The arbitrary fuel supply amount θ to the engine 1 is represented by θ in FIG.
= Θc, this is a factor that causes the engine 1 to operate at the intersection of the characteristic line with the constant fuel supply amount θc and the economical fuel consumption characteristic line Eh, which detects the rotational speed ne of the engine 1, The detected value is controlled to be ne = nec, or the torque Te of the engine 1 is detected,
The control is such that the detected value becomes Te = Tec.

The control device 4A controls the load on the engine 1 by operating the speed ratio e in the transmission 2B for an arbitrary fuel supply amount θ linked to the instruction value from the accelerator pedal. In the load control, the speed ratio e is controlled so that the deviation between the actual load in the engine 1 and the specified load in the arbitrarily set fuel supply amount θ becomes zero. In that case, the detected load is changed to the rotational speed n of the engine 1.
e, the actual rotational speed ne of the engine 1 and
The control is such that the deviation of the fuel supply amount θ from the specified rotation speed is zero.

More specifically, this control will be described. When the fuel supply amount θ set by depressing the accelerator pedal is θ = θc, the control device 4A executes the actual rotation speed ne of the engine 1 And the specified rotational speed ns = ne of the engine 1 at the fuel supply amount θc.
c (FIG. 4).

When the deviation dn = ns-ne is dn> 0, the control device 4A decreases the speed ratio e. When the speed ratio e is reduced, the load (torque Te) of the engine 1 is reduced from the relationship Te = T2 × e (6) in the above equation (4), and the actual rotation speed ne of the engine 1 is reduced. The deviation dn increases and decreases. Note that T2 is the drive torque T2 generated on the output shaft 2b due to the running resistance at the present time.

In contrast to the above case, the deviation dn is dn <dn.
If it is 0, the speed ratio e is increased. Then
As can be understood from the above equation (6), the load (torque Te) on the engine 1 increases, the actual rotational speed ne of the engine 1 decreases, and the absolute value of the deviation dn decreases.

By controlling the speed ratio e, the engine 1
Is the point c in FIG. 4, and the torque Te of the engine 1 in that state is Te = Tec.

In this control mode, the output power of the engine 1 and the power of the output shaft 2b are equal.
Also becomes the characteristic Pc. As a result, in that state, the rotation speed n2 of the output shaft 2b exists on the characteristic Pc in FIG. 2 in a steady state. In that case, assuming that the gradient of the traveling road surface is zero, the operating point is located at the point f in FIG.

Alternatively, when the traveling road surface gradient is the traveling resistance characteristic P21 of FIG.
The operating point b is located at the intersection c1 of the characteristic Pc and the running resistance characteristic P21 in FIG.

Further, at the point c1, when the fuel supply amount θ at the position where the accelerator pedal is depressed while the vehicle is running increases to, for example, θ = θa (FIG. 4), the transmission unit 2B performs the same operation as described above. By controlling the speed ratio e, the rotation speed ne of the engine 1 is made to match the specified rotation speed ns = nea at the fuel supply amount θa.

As a result, similarly to the above, the torque on the output shaft 2b increases, and the surplus torque on the output shaft 2b corresponding to the increased amount becomes acceleration torque, and the rotational speed n2 of the output shaft 2b is reduced to c1 in FIG. Increase, like the arrow from the point. Eventually, when the vehicle reaches a steady state from the acceleration, the vehicle reaches an equilibrium state at a point a2 on the same running resistance characteristic P21. As a result, as shown in FIG. 2, the speed ratio e is changed from e = e1 at point c1 to e = e1 at point a2.
e2.

Even if the required power is equal to or higher than a predetermined power, if the depression speed of the accelerator pedal is equal to or higher than a predetermined value, an assist (motor) for operating the generator G according to the depression speed is performed. assist) driving may be performed.

When the accelerator pedal is returned to zero or the brake pedal is depressed from the state where the required power is equal to or higher than the predetermined power, a power generating action is applied to the generator G according to the degree. If the clutch C1 is disengaged while the clutch C2 is engaged, the braking that recovers the traveling energy of the vehicle can be performed.

Further, when the vehicle speed is reduced by the braking, if the speed ratio e of the transmission portion 2B is reduced, the rotation speed of the rotor R can be maintained at an appropriate high speed by the action. It enables regeneration of braking energy effectively up to the low vehicle speed range. Also, the creeping travel of the vehicle is enabled by the motor action of the generator G while the clutch C2 alone is engaged.

In the control of the engine 1,
The description has always been given of the operation on the economic fuel efficiency characteristic E.
However, it is often difficult in practice to ideally control the engine 1 without deviating from the operation on the economic fuel efficiency characteristic E.

Therefore, when the operation of the engine 1 is shifted from the low power side to the high power side, or vice versa, the operation of the engine 1 in a transient state until the operation of the engine 1 reaches a steady state. Economic fuel economy characteristics E described above
You may miss the top.

In the control, since the output torque of the engine 1 is intentionally quickly raised, the fuel supply amount θ needs to be rapidly raised faster than the response speed of the control system.
Such change control may be performed.

The differential gear 2A in FIG. 1 is composed of a combination of three elements, a sun gear 2c, a ring gear 2f, and a planetary gear 2e, and three elements, a drive shaft 1a, a reaction force axis Ro, and an input shaft 2a. The differential gear may be any combination.

In contrast to the embodiment of FIG. 1, the present invention provides a generator G connected to the input shaft 20a of the conventional continuously variable transmission shown in FIG.
3 in conjunction with each other.

That is, the differential gear 2A combined with the generator G shown in FIG. 1 is used only when the clutch operates to start the engine 1, and otherwise, both clutches C1 and C2 are engaged to generate power. The machine G is substantially directly connected to the input shaft 2a.

This means that in FIG. 3, when the engine 1 is started, the clutch 20A is started with the clutch 20A released, and after the start, the input shaft 20A is driven while the clutch 20A is slid, so that the vehicle can be started. This is the same as the clutch operation in FIG.

Further, if the clutch 20A is engaged after the start, the attitude becomes the same as when both the clutches C1 and C2 are engaged in FIG. Therefore,
The same control can be performed by the mechanism of FIG. 3 regardless of whether the required power is equal to or less than the predetermined power described above.

However, at the time of the above-mentioned clutch operation, the case shown in FIG. 1 is different from the case shown in FIG. In the case of FIG. 1, the relative rotational sliding power between the drive shaft 1a and the input shaft 2a can be converted into electric energy by the generator G and recovered. On the other hand, in the case of FIG. 3, there is a disadvantage that slippage occurring in the clutch 20A of the torque converter or the electromagnetic clutch causes heat loss.

In FIG. 3, when the vehicle runs with only the electric power of the battery 4 shown in FIG.
A may be opened to stop the operation of the engine 1.
Also, during braking, if the generator G is caused to generate power while the clutch 20A is open, the same braking energy as in FIG. 1 can be regenerated.

In the above-described embodiment, the value of the predetermined power Pc may be different depending on the running conditions. For example, when the controllable range of the speed ratio e in the transmission unit 2B is narrow, and the vehicle speed cannot be controlled as instructed by the accelerator pedal by the above control, the value of the predetermined power Pc in the engine 1 is increased or decreased. Correction. Further, in a range where the traveling speed is particularly low, the vehicle often travels in an urban area. Therefore, in consideration of the noise of the engine 1, the predetermined power may be set to a value that makes the rotation speed of the engine 1 more.

[0106]

As described above, according to the present invention, when the required power is equal to or lower than the predetermined low power and the remaining amount of power stored in the battery 4 is smaller than the predetermined value, the operation of the engine 1 is reduced by the fuel efficiency of the economical fuel efficiency characteristic E. While keeping constant to the higher operating point,
On the other hand, a part of the output power from the engine 1 is mechanically transmitted to the output shaft 2b as it is while charging the battery 4 by the power generation in the generator G, so that the energy utilization efficiency of the engine 1 is good.

That is, even in the low level range of the required power, which originally lowers the energy use efficiency, the engine 1
Is operated in the output power range where the fuel efficiency is higher, while generating a part of the power from the engine 1.
Since the battery is charged, the conversion efficiency into electric power is excellent, and the remaining power from the engine 1 can be transmitted to the drive wheels as it is by mechanical power transmission with high power transmission efficiency. Is good.

[Brief description of the drawings]

FIG. 1 is a system diagram showing a hybrid drive device of a continuously variable transmission used in the present invention.

FIG. 2 shows running characteristics of the continuously variable transmission according to the present invention by hybrid driving.

FIG. 3 shows another embodiment of the present invention with respect to FIG. 1 by a system diagram.

FIG. 4 is a characteristic diagram of the engine 1.

FIG. 5 is a system diagram showing a conventional drive device for a continuously variable transmission.

[Explanation of symbols]

Engine, 2 continuously variable transmission, 2a input shaft, 2b
Output shaft, G generator, R rotor, 2B transmission unit, 4 batteries, 4A control device.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) B60L 11/14 ZHV B60L 11/14 ZHV 5H115 F02D 29/00 F02D 29/00 H 29/06 29/06 D 41/02 330 41/02 330Z 41/04 330 41/04 330G 45/00 376 45/00 376B F16H 61/02 F16H 61/02 // B60K 6/02 59:34 F16H 59:34 63:06 63: 06 B60K 9/00 EF term (reference) 3D041 AA21 AA26 AB01 AC01 AC15 AC19 AD00 AD01 AD02 AD10 AD51 AE02 AE03 AE31 AE45 AF01 3G084 BA02 BA03 BA13 BA32 BA34 CA01 CA03 CA04 DA02 DA04 EA11 EB06 EB08 FA03 FA03 FA06 AA07 AA16 BA19 CA01 CA05 CA06 CA07 CB02 CB06 DA01 DA06 DB05 DB11 EA02 EA03 EB03 EC02 EC03 FA05 FA07 FA10 FA11 FB03 3G301 HA01 HA27 JA02 KA08 KA09 KA11 KB01 KB04 LA03 MA 14 NA06 NA07 NC01 NC02 NC06 ND02 ND45 PA11A PB03A PF03Z PF08A PF08Z PF12A PF12Z PG02Z 3J552 MA06 NA01 NB01 NB08 PA59 SB01 UA08 VA32W VA37W VB08Z VB10Z VC02W 5H115 PA12 Q04 Q01 PU08 Q17 PU04 SE08 SJ12 TI01 TO21 TR19

Claims (1)

[Claims] 1. A generator (G) that also acts as a motor on an input shaft (2a) of a transmission (2B) of a continuously variable transmission (2) provided between an output of an engine (1) and driving wheels. And a battery (4) that operates in conjunction with the generator to charge the power generated by the generator and cause the generator to operate as a motor using the charged power.
In the control for operating the speed ratio e = n2 / n1 obtained by dividing the rotation speed n2 by the rotation speed n1 of the input shaft in b), the controller (4A) supplies an arbitrary constant fuel supply amount ( θ), the specified load in the engine at which the fuel efficiency of the engine is the best is stored as data, and the driving power required for the drive wheels is equal to or less than a predetermined power, and the amount of power stored in the battery is stored. Is less than or equal to a predetermined value, the control device sets the fuel supply amount to a constant value corresponding to the engine outputs the predetermined power, the power level generated by the generator, the The load on the engine is controlled to a level at which the specified load of the engine is applied to the fuel supply amount set to a constant value, and the fuel supply amount is linked to the instruction value of the required power. A hybrid drive method for a continuously variable transmission that controls the speed ratio.