JPS62221806A - Electric automobile with torque converter - Google Patents

Abstract

PURPOSE:To miniaturize a motor on board a vehicle by actuating a torque converter at starting and when going up a slope. CONSTITUTION:A control computer 22 operates the output torque demanded to a motor 10 based on the output signal of a pulse generator 14 connected to a select switch 16, an accelerator sensor 18, a brake sensor 20 and a motor 10, supplying its result to a motor control circuit 34. Based on the opening extent of the accelerator and on the car speed if it is judged that the car is about to start or to go up aslope, a lockup mechanism is turned OFF to increase the output of a motor 10 built in a torque converter connected to the motor 10. Thus the motor can be miniaturized.

Description

[Detailed Description of the Invention] [Industrial Application Field] This invention relates to an electric vehicle equipped with a torque converter, in particular, to generate high torque when necessary by combining a torque converter with a lock-up function with a vehicle drive motor. Kotono (Kiru Torque Comparty) related to electric vehicles.

[Prior Art] Electric vehicles are being researched as pollution-free vehicles that do not produce harmful exhaust gases, and some are already at the stage of practical use.

As is well known, motors used in electric vehicles are torque-controlled, unlike normal industrial motors, and in order to perform the necessary torque control and stabilize the vehicle's handling performance,
The motor is controlled by vector control or slip frequency control.

Conventional electric vehicles often do not have a clutch mechanism or transmission mechanism because of the simplicity of construction and ease of handling, and even if the vehicle is equipped with a transmission mechanism, the mechanism is It was as simple as manually selecting the gear when stopped.

[Problems to be solved by the invention] Conventional problems By the way, electric vehicles that do not have a transmission (R) require a motor that corresponds to the output power required for the vehicle, so generally high torque There was a problem that manual transmissions, such as those in the previous model, were not equipped with a popular type of motor, and the driving operation was complicated.

In addition, since electric vehicles use a motor as their drive source, they are capable of O-speed control, so they usually do not have a starting mechanism (clutch). torque control had to be performed.

[Purpose of the invention] This invention has been made to solve the above problems,
By combining an i~silk converter with a vehicle drive motor, it is possible to reduce mechanical shock and amplify the output torque when necessary, thereby making the motor more compact. The purpose is to provide automobiles.

[Means for Solving the Problems and A'1] An electric vehicle with a torque converter according to the present invention includes a torque converter that is connected to a motor and has a built-in lock-up mechanism, and a sensor that detects the running state of the vehicle. a control converter that commands the output torque required of the motor based on the output signal from the sensor and the detection sensor, and issues an on/off control command to a lock-up mechanism of the torque converter;
The motor control circuit is characterized in that it includes a motor control circuit that drives the motor based on a command from the control converter.

If the current vehicle speed is lower than a predetermined value, or if the accelerator opening is larger than a predetermined value even if the vehicle speed is high, the lock-up mechanism is automatically turned on when the vehicle starts or climbs the hill. It will be switched to the off state.

As described above, when the lock-up mechanism is in the on state, the torque converter's human power shaft and output shaft are mechanically coupled, but when necessary, torque can be transferred from the input shaft to the output shaft via fluid. The converter amplifies the output torque of the motor, allowing a relatively small motor to increase the power of the vehicle without changing gears.

In addition, since the motor speed can be easily controlled,
By temporarily reducing the motor torque when switching the lock-up mechanism, it is possible to alleviate the mechanical shock that occurs when switching between lock-up mechanisms.

[Example] Hereinafter, preferred embodiments of the present invention will be described based on the drawings.

FIG. 1 shows a control block diagram of an electric vehicle according to the present invention. In the figure, a torque converter 12 is connected to a motor 10, and this torque converter 12 has a lock-up mechanism (hereinafter referred to as L/U) (not shown).
) is built-in.

This 1-/U includes a lock-up clutch for engaging the input shaft and output shaft of the torque converter 12, and by actuating this clutch with the hydraulic unit 13,
Power transmission between the human power shaft and the output shaft, which had previously been performed using fluid, is now performed mechanically, and power loss due to slip during fluid transmission is prevented.

The motor 10 may be either a DC motor or an induction motor, but in this embodiment an induction motor is used, and the rotation speed of the induction motor 10 is detected by a pulse generator 14.

Further, a select switch 16, an accelerator sensor 18, a brake sensor 20, etc., which detect forward and backward drive commands of the vehicle, and the like are provided as sensors to detect the running state of the vehicle. Each of these detection signals is sent to the CPU 24 and the input/output l10.
26.28, other ROM30. The signals are supplied to a control computer 22 including a storage device such as a RAM 32, and the control computer 22 controls the motor 10 based on each of the detection signals.
The output torque required for is calculated and the result is supplied to the motor control circuit 34, and a command is sent to the control hydraulic unit 13 of the torque converter 12 to control on/off of L/Ll.

The motor control circuit 34 receives power from the battery 36 and drives the motor 10 by converting the DC power horn into AC power via the inverter main circuit 38 .

A method for controlling an electric vehicle according to the present invention having the above configuration will be explained based on the control flowcharts shown in FIGS. 2(a), (b), and (C).

In step 101, the accelerator opening degree θ. . . The basic value of the torque ``1m'' which is instructed to the motor 10 based on the magnitude of is used. In this case, as shown in FIG.
Motor output torque T... is accelerator opening degree θ. . . determined in proportion to. That is, in the figure, the horizontal axis indicates the motor rotation speed N(rr)m), a positive region indicates forward rotation, and a negative @ region indicates reverse rotation. The vertical axis is 9 motor output torques.
shows.

Now, when the electric vehicle is stopped, it is at the position indicated by the symbol a, and when moving forward in this state, the accelerator is opened, and the motor output torque reaches the characteristic where the accelerator opening θACC is 1()0%. increases rapidly toward b. The electric vehicle starts when the motor starts running and torque is generated, and as shown by the solid line, the motor rotation speed N increases sequentially, and at a constant motor rotation speed, that is, position C, the motor output torque also decreases sequentially toward d. . When the accelerator is released from d, the motor rotation speed N is not maintained at a constant level, and the output torque l-m decreases overnight to e, and furthermore, at this accelerator opening degree, the motor rotation speed N increases toward f.

When stopping the car from f, the accelerator is released and the brake is depressed, the motor output torque T... shifts to the negative region, and the motor output torque Tm is maintained at 0 determined by the brake depression state, and this state is Indicates regeneration status. As the brake is depressed, the motor rotation speed N decreases sequentially, and at h, the vehicle stops and returns to the original position a.

The characteristics shown in FIG. 3 are determined in advance according to the model of each electric vehicle, and this characteristic data is written in the ROM 30 of the control computer 22, and can be changed as appropriate according to the driving command and driving conditions. The value is read.

However, 1 herc Tm actually supported by the motor 10 is specified as a value corrected in consideration of the shock at L/U ON/27 of the torque converter 12.

In step 102, it is determined whether the current vehicle speed is above a certain value (Vo), and if it is above Vo (for example, 10.../]1), it is assumed that the start has been completed and L/IJ is turned on, and the vehicle speed is If it is less than or equal to Vo, the on/off state of the L/U is determined in step 103.

When 1-/U is on, control is performed to switch L/lJ from on to off in step 110. In addition, if the /U is in the OFF state in step 103, the basic torque Tm obtained in step 101
In step 108, the torque correction is set to zero so that the command torque becomes the command torque, and the process proceeds to step 111. In step 111, a correction value is added to the basic torque Tm, and this value becomes the torque command value to the motor.

Further, in step 102, the vehicle speed is V. Even if it is above (that is, while driving), the accelerator opening degree θ is determined in step 104. If C is greater than a certain value 00 (for example, the accelerator opening is about 70%), the process proceeds to step 105, where it is further determined whether 1-/U is on, and if it is on, the process proceeds to step 110. In order to increase the motor torque at the torque converter 12, [/U is turned off.

In step 104, if the accelerator opening degree θACC is smaller than θO, the process advances to step 106 and L/
It is determined whether U is in the on state. Further, in step 105, if the state is L/U or A), the process proceeds to step 108, and proceeds to step 111 without performing the 1 to 1 torque correction.

Next, in step 106, the accelerator opening degree θ^. .

is small and L/U is in the ON state, the process proceeds to step 107, the torque correction is set to zero, and the process proceeds to step 111.
Proceed to. If L/lJ is in the OFF state in step 106, the process proceeds to step 109, where control is performed to switch L/U from the OFF state to the ON state while taking into consideration the mitigation of the shock at the time of switching.

Here, the correction control by the subroutine from OFF to ON of the L/U in step 109 will be explained with reference to FIG. 2(b).

In step 112, if the absolute value lNm-N0I of the sliding skewer of the torque converter 12 is greater than or equal to a certain value (Δn), a switching shock will occur to change the L/U from the off state to the on state, so in step 114 1
- Correct motor 1 to torque while keeping /U in the off state [
For example, if the correction value -K (N...-No>], the amount of slippage is less than a certain value (8n), it is determined that the shock at the time of switching is small, and in step 113, the torque correction is set to zero and L is set. Switch /U from off to on.

Next, the correction control by the subroutine when switching the I/U from the on state to the off state in step 110 will be explained with reference to FIG. 2(C).

That is, in step 115, the I/U is switched from on to off, and at this time, in order to correct the output torque that decreases due to the rotation speed of the motor, step 1
In step 16, for example, the correction value - is corrected by ''×self m.

Here, K- is a constant corresponding to the inertial force of the motor, and white m is the differential value of the motor rotation speed (this value takes a positive or negative value depending on the increase or decrease of the rotation speed). In this embodiment, steps 102, 104, 112
Addition of hysteresis necessary for determination in steps 107, 108, and 113.

Although smoothing processing and the like when changing the correction values in steps 114 and 116 are not described, they are of course necessary.

As explained above, by combining a torque converter with a vehicle drive motor and using the torque increasing function of the torque converter when high torque is required, such as when starting a vehicle or climbing a hill, a relatively small motor can be used. It is possible to amplify the output generated by the motor without changing the speed. Also,
When switching the L/U of the torque converter, the shock at the time of switching can be easily alleviated because the rotation speed of the motor can be controlled.

[Effects of the Invention] As explained above, the present invention provides a control system that controls the torque converter by controlling the torque converter connected to the motor and having a built-in lock-up mechanism, and the output torque of the motor based on signals from the detection sensor 1. By including a computer and a motor control circuit, the torque converter can be operated to increase the output torque when the vehicle starts or climbs up the hill, thereby making it possible to downsize the motor to be mounted on the vehicle.

Further, when the vehicle is running, the mechanical shock transmitted from the motor to the vehicle due to the slipping action of the torque converter can be effectively alleviated.

[Brief explanation of drawings]

Fig. 1 is a control block diagram of an electric vehicle with a torque converter according to the present invention, Fig. 2 (a), (b), and (C) are control flowcharts used in an embodiment of the present invention, and Fig. 3 is a control block diagram of an electric vehicle with a torque converter according to the present invention. FIG. 3 is a diagram showing the relationship between motor rotation speed and output torque in a running state of the vehicle. 10... Motor 12... Torque converter 16... Select switch 18... Accelerator sensor 20... Brake sensor 22... Control computer 34... Motor control circuit.

Claims (1)

[Claims] A torque converter that is connected to the motor and has a built-in lock-up mechanism, a detection sensor that detects the driving state of the vehicle,
A control computer that calculates the output torque required of the motor based on the output signal from the detection sensor and issues an on/off control command to the lockup mechanism of the torque converter, and a motor control circuit that drives the motor based on the command from the control computer. An electric vehicle equipped with a torque converter, characterized in that the torque converter is operated at least when the vehicle starts to increase output torque.