JPH02144233A - Slip prevention device for vehicle - Google Patents

Abstract

PURPOSE:To make troublesome operation for slip prevention dispensable by controlling engine output in the slip decreasing direction, or limiting the change- speed position of an automatic transmission in the slip decreasing direction, when actuating of a slip prevention device for wheels is detected. CONSTITUTION:When a slip prevention device 19 is actuated at running on a low friction road, transistor TR1 becomes ON condition by a setting time through a retriggerable timer 18, electric current is supplied to a coil 17L, and relay contacts 17N, 17S are on the position of dotted line. Hereupon, a snow-mode-pattern is selected in a change-speed control circuit 12, and selection of a first speed in an automatic transmission is obstructed so as to prevent impossibility for starting on a low friction road or lateral slip at acceleration. Meanwhile, at no actuation of the slip prevention device 19 (at usual running), the relay contacts 17N, 17S are on the position of full line, and change-speed pattern is decided according to the position of a mode selection switch 15 operated by a driver.

Description

[Detailed description of the invention] (Industrial application field) The present invention relates to a slip prevention device for a vehicle.

(Prior art) Vehicle slips include acceleration slip when the engine power drives the wheels via the transmission, and deceleration slip when the wheels are braked by the brake system. These slips occur on low-friction roads. easy.

Among these slips, for example, as a countermeasure against acceleration slip, the driver manually switches the mode, usually based on the normal mode shift pattern shown in Fig. 6 (shift pattern of automatic transmission that performs shift control). As shown in Figure 7, the automatic transmission is prevented from selecting the first gear by switching to a snow mode shift pattern that eliminates the first gear range, thereby preventing acceleration slippage due to the large torque in the first gear. The applicant of this application previously published the technology to prevent this in Nissan Jidosha Co., Ltd. "Service Bulletin" No. 579, No. C-1, published in June 1988.
It has already been proposed as described on page 5.

(Problem to be solved by the invention) However, the conventional anti-slip devices typified by this require manual operation by the driver in order to reduce the occurrence of slips. Judgment and operation are required, and in the case of a driver who is not familiar with the vehicle or who is lazy, the actual situation is that the above-mentioned operation cannot be expected and the effect of the measures is not necessarily obtained. .

In the case of a vehicle equipped with a device such as a traction control device (for acceleration slip) or an anti-skin control device (for deceleration slip) that prevents wheel slip, the present invention applies to road surface conditions where slip is likely to occur when this device is activated. In view of this, it is an object of the present invention to solve the above-mentioned problem by making the above-mentioned slip countermeasure automatically function at this time.

(Means for Solving the Problems) For this purpose, the anti-slip device of the present invention provides a vehicle capable of traveling by driving wheels using power from an engine via an automatic transmission, and equipped with a device for preventing wheel slip. a slip prevention operation detection means for detecting the operation of the device; and when the device is activated, at least one of controlling the output of the engine in the direction of decreasing slip or limiting the shift position of the automatic transmission in the direction of decreasing slip. The system is equipped with a power train control means for controlling the power train.

(Function) Power from the engine is transmitted to the wheels via the automatic transmission, and the vehicle can travel by driving the wheels. and,
If the wheels slip, the device operates to prevent this.

The anti-slip operation detection means detects that this device is activated, and upon this detection, the power train control means controls the output of the engine in the direction of reducing slip, or limits the gear position of the automatic transmission in the direction of reducing slip. Alternatively, by implementing both of these, slips are less likely to occur.

By the way, this slip countermeasure automatically functions by detecting the operation of the slip prevention device on the 1st floor, which eliminates the hassle of manual operation by the driver and ensures that even if the driver is inexperienced or lazy, it will prevent slips. It is possible to achieve the desired objective by taking appropriate measures.

(Example) Embodiments of the present invention will be described in detail below with reference to the drawings.

FIG. 1 shows an embodiment of the device of the present invention. In this embodiment, the shift pattern of an automatic transmission is automatically switched to prevent slippage from occurring.

In the figure, 1 indicates a front wheel, and 2 indicates a rear wheel, and these wheels are suspended on a vehicle body 5 by suspension devices 3 and 4, respectively. Also, 6
indicates the engine, and 7 indicates the automatic transmission. The engine 6 manually outputs an output to the automatic transmission 7 according to the opening degree of a throttle valve 9 which is controlled by the driver via an accelerator pedal 8 . The automatic transmission 7 changes the speed of this engine power according to the selected gear position (shift position), transmits it to the rear wheels 2 via the propeller shaft 10 and the differential gear 11, and drives these to drive the vehicle.

The gear position of the automatic transmission 7 is determined by a shift control circuit 12, and for this determination, the circuit 12 includes a signal from a throttle sensor 13 that detects the opening degree T1 of the throttle valve 9, and a vehicle speed sensor that detects the vehicle speed. The signals from 14 are manually transmitted.

The circuit 12 determines the gear position of the automatic transmission 7 from the combination of the throttle opening TH and the vehicle speed ■, and the basic shift pattern is determined by an existing mode selection switch 15 and a shift pattern change circuit 16, which will be described later, as shown in FIG. The normal mode pattern shown in FIG. 7 or the snow mode pattern shown in FIG.

The mode selection switch 15 has a normal mode contact 15N and a snow mode contact 255, which are grounded dynamically irrespective of the pattern desired by the driver. Contact 15N is connected to the corresponding input of circuit I2 via contact 17N of relay 17, which is part of pattern change circuit 16, and contact 155 is connected to circuit 12.
Connect directly to the corresponding input of the relay 17 and contact 17 of the relay 17.
Ground through S. Relay 17 turns on contact 17N and turns off contact 175 as shown by the solid line when coil 17L is deenergized.
L, these contacts 17N when the coil 17L is energized.

17S shall be switched ON and OFF as shown by the dotted line.

The coil 17L is connected to the power source 1, and the collector-emitter path of a transistor TRI is inserted into the electrical circuit, and the base of the transistor is connected to the slip of an I-traction control device or an anti-strain control device through a retriggerable timer 18. Connect the prevention device 19. As is well known, the traction control device reduces the wheel driving force (engine output, etc.) to prevent acceleration slip (wheel spin) of the drive wheels 2, and the anti-skid control device reduces the wheel drive force (engine output, etc.) when the wheels 1 and 2 are braking, as is well known. It operates to reduce brake fluid pressure to prevent deceleration skids. When the slip prevention device 19 is activated, the retrigable timer 18 changes the output to the level (1) for a certain period of time in response to a signal from this and turns on the transistor TRI, but the slip prevention device 19 is activated again during this certain period of time. Then, it is assumed that the retriggerable timer 1 day keeps the output at H level for a certain period of time from this instant.

Next, the operation of the above embodiment will be explained. While driving on a normal road where the anti-slip device 19 does not operate, the IJ l-regable timer 18 keeps the output at L level and the transistor TRI
By turning off the coil 17L, the coil 17L is deenergized.

Therefore, the relay 17 sets the contacts 17N and 17S to the solid line position, and the shift pattern is determined as follows depending on the position of the mode selection switch 15 operated by the driver.

That is, the driver switches the switch 15 to the normal mode contact 15.
When set to the N side, this switch connects circuit 1 through contact 17N.
2 is grounded, and the input of the circuit 12 connected to the snow mode contact 15S is cut off. In this case, circuit 12
selects the normal mode pattern shown in FIG. 6, and the circuit 12 determines the gear position of the automatic transmission 7 in accordance with this. When the operator places switch 15 to snow mode contact 15S, the switch reverses the grounding and disconnection of the corresponding input of circuit 12, causing circuit 12 to select the snow mode pattern of FIG.

In this case, the circuit determines the gear position of the automatic transmission 7 according to the pattern, but the shift pattern shown in FIG. 7 does not have a first speed range, so the automatic transmission 7 cannot be in the first speed. Therefore, it is possible to prevent the wheels from slipping due to the large torque of the first speed, making it impossible to start the vehicle, or causing sideslip during acceleration.

By the way, while driving on a low friction road where the anti-slip device 19 is activated, the retriggerable timer 18 turns on the transistor TRI for a set time from this activation.

Then, the coil 171 is activated by the power supply +■ (=
Since the input of the circuit 12 related to this is grounded, the circuit 12 selects the snow mode pattern shown in FIG. To prevent the vehicle from becoming unable to start on a friction road and from causing sideways tilt during acceleration.

Since this snow mode pattern selection is automatically performed when the anti-slip device 19 is activated (when driving on a low-friction road), even if an inexperienced or lazy driver does not switch the mode selection switch 15. , it is possible to ensure that the anti-slip measures using the snow mode pattern function as described above.

Note that the anti-slip device 19 may occur even if the road is not a low-friction road, when a sudden acceleration operation or sudden braking operation is performed. However, the operation in this case is for emergencies, and considering the driver's panicky state of mind, even though this is not a low-friction road, the first gear should not be selected as in F. It is preferable to do so.

Furthermore, in the above example, the shift pattern of the retriggerable timer 18 is returned instantaneously when the output decreases, but it is also possible to gradually return the shift pattern according to the retrigger time of the timer 18. In this case, as a result of interpolation between the normal mode pattern and the snow mode pattern, the automatic transmission 7
The pattern transition is smooth and doesn't feel strange.

FIG. 2 shows another example of the device of the present invention, in which the gear position selection is directly restricted instead of changing the shift pattern to achieve similar effects. For this reason, a gear position limiting circuit 2o is added to the illustrated specific speed change control circuit 12.

First, the shift control circuit 12 will be explained. It consists of a gear position determining circuit 21 and transistors TR2, TR3, TR4, and. The gear position determination circuit 21 determines the gear position based on the information from the sensor 13.14, that is, the throttle opening TH and the vehicle speed ■, according to the shift control shown in FIG. Only 2nd gear hourly output power is set to H level.
It is assumed that only the output Q3 at the third speed is set to the H level, and the entire output at the fourth speed is set to the L level. And these outputs are connected to the corresponding transistors TR2, TI? 3. It is assumed that the corresponding solenoids 22 to 24 are energized by the power supply +■ by connecting these transistors to TR4 and turning on these transistors as appropriate.

The automatic transmission 7 selects the first gear by energizing only the l-speed selection solenoid 22, the second gear by energizing only the second-speed selection solenoid 23, and the third gear by energizing only the third-speed selection solenoid 24. speed,
Further, the fourth speed can be selected by deenergizing all the solenoids 22-24.

Next, to explain the gear position limiting circuit 20, it is provided with a relay 25 in addition to the retriggerable timer 18 and transistor TRI similar to the example shown in FIG.

This relay includes a coil 25L that is energized by the power supply terminal 2 when the transistor TRI is turned on, and contacts 25-1 and 25-4 that are switched from the solid line position to the dotted line position by this energization. The contact 25-1 is used to switch and connect the output Q1 of the circuit 21 to the bases of the transistors TR2 and TR3,
The contacts 25-4 are connected to the outputs Ql of the circuit 21, Q2. The output of the NOR gate 26 which performs the L-level OR of Q3 is used to appropriately connect the base of the transistor TR4.

The operation of this example will be explained next. The circuit 21 determines the gear position as described above and outputs Ql, Q2. It corresponds to the level of Q3. Here, since the slip prevention device 19 is not activated, the relay 25 deenergizes the coil 25L and contacts 25-1.2 by turning off the transistor TRI.
When 5-4 is set to the solid line position, the output Ql of circuit 21
, Q2. Q3 is the corresponding transistor TR2,
By turning on and off these transistors, the automatic transmission 7 can be placed in the first to fourth gear positions as determined by the circuit 21 via the solenoids 22 to 24.

Here, when traveling on a low-friction road where the anti-slip device 19 is activated, the retriggerable timer 18 is activated during the set time from the activation.
Transistor TRI is turned on by the H level output of
1. Switch 25-4 to the dotted line position.

In this case, even if the gear position determined by the circuit 21 is the first speed and the output Ql is set to the H level, this output is effectively changed by turning the transistor TR3 ON L through the contact 25-1 and selecting the second speed. By inhibiting the first speed, the same effect as the example of FIG. 1 can be achieved. Also, the gear position determined by circuit 21 is 4th speed and all outputs are old.

Q2. NOR that receives these even if mouth 3 is set to L level
The H level output of the gate 26 passes through the contact 25-4 and turns the transistor TR4 ON L, thereby selecting the third speed, thereby virtually prohibiting the fourth speed. By inhibiting the fourth speed, high-speed travel on low-friction roads is prevented.

In this example, the configuration is such that the first and fourth gears are completely prohibited when the slip prevention device 19 is activated, but a configuration may be adopted in which the frequency of use of these gear positions is reduced.

3 to 5 are control programs for a computer when the speed change control circuit 12 is configured by a computer. In this example, this program prevents the first speed from being selected when the anti-slip device is activated. The same effect as in the example above can be achieved.

Figure 3 shows the counting program for vehicle speed counter C.
Each time a vehicle speed pulse from the vehicle speed sensor 14 shown in FIGS. FIG. 4 shows a program for setting a time similar to the setting time of the retriggerable timer 18 shown in FIGS. Processing is performed, and a fixed time Ts is set in the timer T each time.

FIG. 5 shows a shift control program that is processed by a regular interrupt. First, in step 31, the vehicle speed counter C (
The vehicle speed V is calculated from the count value (see FIG. 3), and in the next step 32, the vehicle speed counter C is cleared for the next vehicle speed calculation. In the next step 33, Ts in FIG.
Whether or not the timer T, which is set to O and is decremented in step 37, has reached O, that is, the slip prevention device 19
It is checked whether the set time Ts has elapsed since the operation.

During the set time Ts, in step 34, the shift vehicle speed VZ on the 1←2 downshift shift line in the shift pattern of FIG.
+ is looked up in the table based on the throttle opening TH, and in step 35, the vehicle speed ■ in step 31 is 2→
l downshift shift vehicle speed is less than Vg+, that is, the 6th
Check whether it is in the first speed range shown in the figure. ■If it is 2I, set VZ+ to V in step 36, and after executing step 37, adjust the throttle opening TH and vehicle speed in step 38.
Shift control is performed based on FIG. 6. By the way, as a result of the execution of step 36, the vehicle speed V will not be less than VZ+, so if there is no 1st gear range shown with diagonal lines in FIG. 6, the gear shift will be performed based on the same shift pattern.
The same effects as in FIG. 1 can be achieved.

Therefore, while the anti-slip device 19 is not operating, the fourth
Since the program shown in the figure is not executed, even if it is activated again, the timer T is kept at 0 after the set time Ts has elapsed. Therefore, in step 33, steps 34 to 37 are skipped and the control proceeds to step 38, where shift control is performed. In this case, the vehicle speed {circle around (2)} remains the calculation result at step 31, and the gears, including the first speed, are changed as usual according to the pattern shown in FIG. 6.

Note that in this example, the 2->1 shift vehicle speed ■ is left as the lookup value in step 34, but if this is changed as the timer T is decremented and the first speed range is gradually increased, Unnatural windows can be reduced.

Furthermore, in each of the above embodiments, when the anti-slip device is activated, the selected gear position of the automatic transmission is limited to reduce slip, but instead of this, the output characteristics of the engine are changed by delaying the ignition timing or opening the throttle. It can also be lowered by reducing the degree.

It goes without saying that when a continuously variable automatic transmission is used, the same objective can be achieved by limiting the gear ratio instead of the gear position.

(Effects of the Invention) As described above, the anti-slip device of the present invention is configured to limit the shift position of the automatic transmission in the direction of reducing slip when the anti-slip device is activated, and to control the output of the engine in the direction of reducing slip. These controls can be performed automatically without regard to the driver's operations, eliminating the hassle of operation and ensuring that the slip countermeasures function properly even if the driver is inexperienced or lazy. It is possible to achieve the intended purpose.

[Brief explanation of the drawing]

Fig. 1 is a system diagram showing one embodiment of the slip countermeasure device of the present invention, Fig. 2 is an electronic circuit diagram showing another example of the present invention, and Figs. 3 to 5 show still other examples of the present invention. The flowchart of the transmission control program shown in FIGS. 6 and 7 is for automatic transmission 2.
It is a speed change pattern diagram of seeds. ■...Front wheel 2...Rear wheel 6...Engine 7...Automatic transmission 8...Accelerator pedal 9...Throttle valve 11...Differential gear 12...Shift control circuit 13. ... Throttle sensor 14 ... Vehicle speed sensor 15 ... Mode selection switch 16 ... Shift pattern change circuit 17 ... Relay 18 ... Retriggerable timer 19 ... Slip control device 20 ... Gear Position limiting circuit 21...Gear position determining circuit 22-24...Gear position selection solenoid 25...Relay patent applicant Nissan Motor Co., Ltd.

Claims (1)

[Scope of Claims] 1. In a vehicle that can run by driving wheels with power from an engine via an automatic transmission and is equipped with a device to prevent wheel slippage, a slip prevention operation that detects the operation of the device. and a power train control means for controlling the output of the engine in the direction of decreasing slip or limiting the shift position of the automatic transmission in the direction of decreasing slip. Features: Vehicle slip prevention device.