JPH04201657A - Brake controller for retarder device - Google Patents

Abstract

PURPOSE:To always prevent the wheel skid in the electric brake application surely by installing a brake torque calculating means wheel skid judging means, and a brake torque correcting means as the countermeasures for preventing the skid in an electric brake control system. CONSTITUTION:A brake controller for a retarder device is equipped with a brake torque calculating means 42 which determines the brake torque corresponding to the switch operation quantity in the electric brake application, wheel skid judging means 62 for judging the existence of the wheel skid in the electric brake application, and a brake torque correcting means 63 for correcting the brake torque value toward reduction when the skid is generated. Accordingly, during the traveling of a vehicle, the induction device 20 of a retarder device installed in an engine drive system always judges the existence of the wheel skid in the electric brake application, and if skid is generated on a road surface state where slip is easily generated, the brake torque set by a driver is corrected toward reduction. Accordingly, skid can be prevented properly.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is installed in a vehicle such as an automobile, and performs electric braking when braking, converts mechanical energy into electrical energy, and regenerates it in a battery for starting or accelerating. The present invention relates to a brake control device that controls a retarder device to perform auxiliary acceleration using its battery power at times to avoid wheel skidding during electric braking.

[Prior Art] In recent years, the applicant has already applied technology to drive systems of vehicles such as automobiles.
A retarder device has been proposed that is equipped with a squirrel-cage multiphase induction machine capable of generating electricity and electric power, and electrically braking and accelerating. This retarder device aims to compensate for the decrease in engine braking effectiveness due to the downsizing of engines, especially in large vehicles, and to reduce fuel and exhaust gas when starting and accelerating.

That is, during braking, the induction machine installed in the drive system of the vehicle operates as a generator to perform electrical braking, and the electrical energy generated in the induction machine at this time is regenerated into the battery. Also,
When starting or accelerating, the induction machine operates as an electric motor using battery power to provide auxiliary acceleration.

In this way, mechanical energy is converted into electrical energy and regenerated, and this electrical energy is effectively utilized in terms of fuel consumption and exhaust gas. New control systems have been developed to effectively achieve regeneration and effective utilization through such energy conversion, and control systems suitable for this have been proposed. Control of such energy regeneration cycles in vehicles is still under development, and further development is desired.

Conventionally, in the retarder device described above, an electric brake switch is installed in the driver's seat, and the driver can arbitrarily operate the electric brake switch depending on the driving condition.

When the switch is operated by a predetermined amount, a braking torque corresponding to the operation amount is set and the induction motor is operated as a generator to generate a predetermined braking force.

[Problems to be Solved by the Invention] However, in the conventional electric braking control system described above, the braking force can be adjusted according to the driving condition at the discretion of the driver, but on the other hand, it is possible to adjust the braking force according to the driving condition. There may also be cases where the braking force is excessive compared to the amount of cargo loaded. In particular, if too much braking force is applied on a road surface that is prone to slipping due to rain or snow, the wheels may lock and cause skids, impairing maneuverability. For this reason, it is desirable that this electric braking control system also be provided with measures to prevent skids in order to ensure the maneuverability of the vehicle.

The present invention has been made in view of these problems, and an object of the present invention is to provide a brake control device for a retarder device that can always reliably prevent wheel skid during electric braking.

[Means for Solving the Problem] In order to achieve this object, the present invention includes a squirrel-cage multiphase induction machine capable of generating electricity and electric power installed in the engine drive system, and is connected to the battery that regenerates the generated power via the inverter circuit, and the resistor that consumes excess power, and the rotating magnetic field of the induction machine is delayed by a predetermined amount from the inverter control circuit that receives the switch signal operated by the driver.
Or output a control signal to the inverter circuit to advance the
A retarder device that separates the engine drive system between electric braking and auxiliary acceleration includes a braking torque calculation means that determines the braking torque according to the amount of switch operation during electrical braking, and a braking torque calculation means that determines the presence or absence of wheel skid during this electrical braking. The present invention proposes a braking control device for a retarder device, which includes a wheel skid determining means for determining a wheel skid, and a braking torque correcting means for correcting a value of braking torque to decrease when a skid occurs.

[Function] According to the configuration of the present invention described above, the induction machine of the retarder device installed in the engine drive system while the vehicle is running operates as a generator by the driver's switch operation and performs electric braking when exiting the vehicle. , when accelerating, etc., it operates as an electric motor to provide auxiliary acceleration. During this electric braking, the presence or absence of wheel skid is constantly determined, and if a skid occurs on a road surface that is prone to slipping, the braking torque set by the driver is corrected to reduce the skid. This makes it possible to accurately prevent this.

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

FIG. 1 is a block diagram showing an embodiment of the retarder device and its charging state display device of the present invention, and the retarder device 10 is a squirrel cage multiphase induction motor 20 installed in an engine drive system.
The squirrel-cage polyphase conductor 20 is attached to the flywheel 3 of the crankshaft 2 of the engine 1, and the flywheel 3 is connected to the flywheel 3 via the clutch 4 and the input shaft 5. It is configured to be transmitted to a transmission 6.

This squirrel-cage polyphase conductor 20 is three-phase, and is installed inside a flywheel device 7 provided between an engine 1 and a transmission 6, as shown in FIG. That is, the stator core 22 is attached to the stator ring 21 fixed between the flywheel housings 7a and 7b of the flywheel device 7, the stator winding 23 is attached to the stator core 22, and the exit wire is connected to the stator winding 23. 24 is taken out to form the stator section 20a. Further, a rotor core 25 is attached to the outer periphery of the flywheel 3 in close opposition to the stator core 22, and a squirrel cage winding 26 is attached to the rotor core 25 together with a retaining ring 27 and an end ring 28, and the rotor part 20b to accomplish. Therefore, while the engine l is stopped or running, the rotor section 20b is stopped or rotationally driven, and a predetermined frequency voltage is applied to the stator section 20a to apply a rotating magnetic field to the rotor section 20b. It is designed for braking or auxiliary acceleration.

To explain the electric control device 30 in FIG. 1,
The stator section 2Oa side of the squirrel cage induction machine 20 is connected to a battery 33 via an inverter circuit 31 and a capacitor 32,
The inverter circuit 31 has an inverter control circuit 40 that generates a frequency voltage control signal. Inverter circuit 31
A resistor 3 is connected to the output side of the resistor 3 via a semiconductor switch circuit 34.
5 is connected, and a switch control circuit 36 is connected to the semiconductor switch circuit 34.

In addition, as various input information, the rotor section 20b of the induction machine 20
a rotation sensor 50 that detects the shaft rotation speed N, a voltage detection circuit 51 that detects the output voltage Ev of the inverter circuit 31,
Temperature sensor 5 detects temperature t by the current of resistor 35
2. Accelerator depression amount θ in conjunction with accelerator pedal 11
It has an accelerator sensor 53 that detects. Furthermore, the inverter circuit 31 is provided with an electric brake switch 54 operated by the driver during deceleration and braking, and an auxiliary acceleration switch 55 operated similarly during acceleration. It has a plurality of switch elements connected between the positive and negative terminals of the battery 33. The switching element consists of a transistor and a diode connected in parallel in the opposite direction of this transistor, and the inverter control circuit 40
A switching control signal SR of a predetermined frequency is sent to the transistor from
By applying SF, the slip direction and slip amount of the rotating magnetic field of the induction machine 20 are changed, and the induction machine 20 operates as a generator or electric motor with a predetermined capacity.

The inverter control circuit 40 has an electric brake switch 54, an auxiliary acceleration switch 55, and an operation mode setting circuit 41 into which a signal of the shaft rotation speed N is input. electric mode,
Set stop mode. Therefore, as a power generation control system, there is provided a braking torque calculation circuit 42 to which the power generation mode signal of the operation mode setting circuit 41 and a signal corresponding to the operation amount α of the electric brake switch 54 are input. The braking torque TB is determined according to the amount α. The braking torque T and shaft rotational speed N signals are manually input to the rotating magnetic field delay control circuit 43 to obtain a negative slip amount -eR corresponding to the braking torque TB.
It is converted into a control signal S, whose frequency is delayed by R. Then, this control signal SR is output to the inverter circuit 31,
The induction machine 20 operates as a generator with a predetermined power generation capacity, and the AC voltage generated by the induction machine 20 is converted into DC voltage and regenerated to the battery 33. In this case, a negative slip amount -e is set proportionally to the braking torque T, and the braking torque TIS is controlled to follow the set value.

In addition, as an electric control system, the operation mode setting circuit 41
It has a driving torque calculation circuit 44 in which signals of the electric mode, the accelerator depression amount θ, and the shaft rotation speed N are manually input, and the generated engine torque TP is calculated using the torque characteristics according to the accelerator depression amount θ and the shaft rotation speed N. The driving torque T shared by the electric motor. Establish. This driving torque TD,
The signal of the shaft rotational speed N is manually input to the rotating magnetic field advance control circuit 45 to determine the positive slippage +e corresponding to the drive torque TD, and the frequency is controlled by increasing the slippage +e with respect to the shaft rotational speed N. Convert to signal SP. Then, this control signal SF is similarly outputted to the inverter circuit 31, and the induction machine 20
operates as an electric motor with a predetermined electric power, and provides supplementary driving force to the drive system of the engine l. In this case, the greater the accelerator depression amount θ and the generated engine torque TP, the greater the drive torque TO shared by the electric motor is controlled.

The battery 33 regenerates and stores electrical energy generated during electric braking, and has a capacity V that can be charged to the rated charging capacity in a short period of time and that does not cause over-discharge even when repeatedly discharged. Set.

Next, the charging and discharging control system for the battery 33 will be described. A charging control circuit 37 and a discharging control circuit 38 are connected to the battery 33. When the power generation mode signal from the operation mode setting circuit 41 is input, the charging control circuit 37 adjusts the terminal voltage E0 of the battery 33 to a chargeable voltage. When the battery 33
Supply current to and charge. When the electric mode signal is input, the discharge control circuit 38 generates a DC power supply voltage E necessary for operating the induction machine 20 as a motor, and applies this voltage EM to the induction machine 20 during starting and acceleration.

The resistor 35 consumes electrical energy when the generated electrical energy is too excessive to be regenerated, and is set to a predetermined resistance value r.

Here, if the resistance value r of the resistor 35 is constant, the power consumption P of the resistor 35 exceeds the generator output W at a predetermined rotation speed or higher, and the inverter output voltage EV decreases, causing the braking torque Tests have confirmed that T. The semiconductor switch circuit 34, switch control circuit 36, and voltage detection circuit 51 described above have the following braking torque T,
This is a resistance value control circuit that prevents a decrease in resistance.

Therefore, when the inverter output voltage Ev detected by the voltage detection circuit 51 exceeds the set value, the switch control circuit 36
An opening/closing control signal having a duty ratio corresponding to the shaft rotational speed N is output to the semiconductor switch circuit 34. Then, the semiconductor switch circuit 34 controls opening and closing of the circuit of the resistor 35, and the effective resistance value r of the resistor 35 is
, to keep the inverter output voltage Ev approximately constant,
The braking possible region where the braking torque T6 is large is expanded. In this way, by controlling the effective resistance value r of the circuit including the resistor 35 by opening and closing the semiconductor switch circuit 34, the value r of the resistor 35 itself is set to a small value.

Further, as a result of the test, it was confirmed that when electric braking is continued for a long time, the temperature t of the resistor 35 increases, the resistance value r increases, and the braking torque re decreases accordingly. Therefore, in order to prevent this, the signal from the temperature sensor 52 provided in the resistor 35 is input to the switch control circuit 36,
As the temperature t rises, the duty ratio of the signal to the semiconductor switch circuit 34 is changed, and the effective resistance value of the resistor 35 is changed.
5 is controlled to decrease.

Next, skid prevention control in the electric braking control system will be explained. First, there is a front wheel rotation sensor 60 that detects the front wheel rotation N, and a rear wheel rotation sensor 61 that detects the rear wheel rotation NR. The signal is input to the skid determination circuit 62. The skid determination circuit 62 calculates, for example, a rotation difference ΔN between the front and rear wheel rotations Nr and NR under the electric braking conditions in which the electric braking switch operation signal is input, and calculates the rotation difference ΔN between the rotation difference ΔN and the case of full steering during normal turning. When the rotation difference ΔN becomes larger than the limit value ΔN, skid due to wheel lock is determined. This skid determination signal is transmitted to the braking torque correction circuit 6.
3, and the correction coefficient k in the case of non-skid, k=
Set to 1. In the case of a skid, the correction coefficient k is set in the range O<k<1 as a decreasing function with respect to the rotational difference ΔN, as shown in FIG. Then, a signal corresponding to this correction coefficient is input to the braking torque calculation circuit 42, and the braking torque TB is
is multiplied by the correction coefficient k to obtain the braking torque T in the event of a skid.
, is adapted to be corrected by decreasing it for a predetermined period of time.

Next, the operation of this embodiment will be explained. First, the power from the engine 1 is transmitted to the flywheel 3, clutch 4, input
The shifting power is input to the transmission 6 through the shaft 5, and the shifting power is transmitted to the wheels, thereby causing the vehicle to run. When the driver operates the electric brake switch 54 when exiting the vehicle during driving, the operation mode setting circuit 41 of the inverter control circuit 40 selects the power generation mode, and the braking torque calculation circuit 42 selects the electric brake switch 54 according to the switch operation amount α. A braking torque T is set. Then, a frequency control signal SR with a negative slip amount -eR corresponding to the braking torque Ta is input from the rotating magnetic field delay control circuit 43 to the inverter circuit 31, and the induction machine 20 is operated as a generator.

As a result, in the induction machine 20, the rotating magnetic field of the stator section 20a forcibly decelerates the rotation of the rotor section 20b of the drive system, generating a braking torque Ta as shown in FIG. Therefore, braking is performed directly with this braking torque TB, or the engine braking effect is increased and corrected, making it possible to appropriately brake or decelerate.

At this time, electric energy is generated in the stator section 20a of the induction machine 20 due to the operation of the generator, which is converted into a DC voltage by the inverter circuit 31, voltage-regulated by the charging control circuit 37, and supplied to the battery 33. The electric energy generated by electric braking is thus effectively regenerated.

During this electric braking, if the electrical energy is excessive, the semiconductor switch circuit 34 causes a predetermined current to flow through the resistor 35 according to the opening/closing control signal of the switch control circuit 36, thereby consuming the braking torque TB. The excess amount is quickly dissipated while controlling the alignment to prevent failure. Furthermore, in the case of excessive energy consumption by this resistor 35, when the resistance value r increases due to temperature rise, the effective resistance value "," is decreased by the switch control circuit 36, so as to maintain the above-mentioned matching control in an optimal state. It is corrected to

On the other hand, when the driver operates the auxiliary acceleration switch 55 during acceleration by pressing the accelerator, the operation mode setting circuit 41 selects the electric mode. Then, the drive torque calculating circuit 44 calculates the drive torque TO to be shared by the electric motor according to the running state in this case, and based on this, the rotating magnetic field advancement control circuit 45 sends a frequency control signal S of the positive slip amount eF.
, is input to the inverter circuit 31.

Further, in this electric mode, the discharge control circuit 38 generates a predetermined DC voltage power source EM using the battery power source.

In this way, a voltage sufficient to electrify the induction machine 20 is applied to the induction machine 20, and a rotating magnetic field that is faster than the shaft rotation speed N is generated in the stator section 20a, so that the induction machine 20 operates as an electric motor. A predetermined driving torque To is generated as shown in the figure. Therefore, the power of the drive system of the engine 1 is transferred to the induction motor 2.
The electric energy regenerated into the battery 33 is effectively used to drive the vehicle as described above, and the fuel consumption and exhaust gas are reduced according to the 18 minute drive torque of the induction motor 20. is effectively reduced.

In addition to the above, the induction machine 20 is operated as an electric motor when the engine is started. Further, during steady running, the induction machine 20 is operated, for example, as a generator with a small power generation capacity to slowly charge the battery, and is controlled with emphasis on energy regeneration.

The effects of the electric braking and auxiliary acceleration described above are repeated indefinitely during deceleration, acceleration, and steady state during driving as long as the life of the battery 33 continues due to the regeneration of energy in the engine drive system. be.

On the other hand, the front and rear wheels rotate N while the vehicle is running as described above.

, NR are detected by the sensors 60 and 61, and when operating the electric brake, the skid determination circuit 62 determines whether or not skid is present based on the rotational difference ΔN between the two. Therefore, when a relatively large braking torque is set and sudden electric braking is performed to suddenly brake the front and rear wheels, it is difficult to set a relatively large braking torque and apply sudden braking to the front and rear wheels. Under conditions where the grip force of the tires is reduced, the front and rear wheels, which are mainly non-driven and have a large braking force, may lock due to excessive braking, resulting in a skid.

In this case, the skid is determined by the sharp increase in the rotational difference ΔN between the front and rear wheels, and based on this skid signal, the braking torque correction circuit 63 sets a correction coefficient k according to the rotational difference ΔN. Then, the braking torque T set by the driver's operation is forcibly reduced by this correction coefficient, and as a result, the braking force of the front and rear wheels decreases depending on the skid condition. As a result, the tire's grip strength is restored, and skid/throttle will no longer occur. In this way, when the driver sets a predetermined braking torque and performs electric braking,
If there is a risk of skidding due to excessive braking due to road surface conditions, this is automatically avoided, and vehicle directionality, steering stability, and braking performance are ensured.

Although the embodiments of the present invention have been described above, the present invention is not limited thereto. For example, when a skid occurs, the braking torque may be finely controlled as in the case of ABS control.

[Effects of the Invention] As explained above, the control system for the electric brake of the retarder device according to the present invention is provided with skid prevention measures, so that skids are reliably prevented when the electric brake is operated. Maneuverability, etc. is ensured, and safety is improved. Since the structure is configured to determine skid based on the difference in rotation between the front and rear wheels and reduce the braking torque, it is possible to appropriately prevent skid by relaxing the braking depending on the skid condition.

[Brief explanation of the drawing]

Fig. 1 is a block diagram of an embodiment according to the present invention, Fig. 2 is a sectional view of the mechanical configuration of a squirrel cage multiphase induction machine, Fig. 3 is a diagram showing correction coefficients for braking torque, and Fig. 'tS4 is a diagram showing braking torque. FIG. 3 is a characteristic diagram showing drive torque. lO... Retarder device, 20... Squirrel cage polyphase induction machine, 30... Electric control device, 31... Inverter circuit, 33... Battery, 35... Resistor, 40...
Inverter control circuit, 54... electric brake switch, 5
5... Auxiliary acceleration switch, 42... Braking torque calculation circuit, 62... Skid determination circuit, 63... Braking torque correction circuit. Patent applicant Hino Motors Co., Ltd. Figure 2

Claims (1)

[Claims] A squirrel-cage multi-phase induction machine capable of generating electricity and electric power is installed in the engine drive system, and the stator side of this induction machine is connected to a battery that regenerates the generated power via an inverter circuit, The inverter control circuit, which is connected to a resistor that consumes power and receives switch signals operated by the driver, outputs a control signal to the inverter circuit that delays or advances the rotating magnetic field of the induction machine by a predetermined amount, and controls the engine drive system. A retarder device that controls electrical braking or auxiliary acceleration of a vehicle includes a braking torque calculation means that determines braking torque according to the amount of switch operation during electrical braking, and a wheel skid determination device that determines whether or not a wheel skids during electrical braking. 1. A braking control device for a retarder device, comprising: means for correcting braking torque to reduce a value of braking torque when a skid occurs.