JPH0465263B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a vehicle running control system that takes measures against malfunctions in a control circuit that occur when engine braking is required.

[Conventional technology]

2. Description of the Related Art A vehicle running control device is known that has a transmission device in which an automatic transmission type sub-transmission is added to a main transmission that changes the gear ratio by a manual transmission operation. A conventional vehicle running control device 1 shown in FIG. 3 includes a one-way clutch 3a in a power transmission path upstream of a main transmission 2 having four speed change gears 21, 22, 23, and 24 from low speed to high speed. It has a transmission 4 which is connected in series with an auxiliary transmission 3 in which a low gear with a hydraulic clutch 6 and a high gear with a hydraulic clutch 3b are connected in parallel.
is transmitted to the axle 7 via.

The transmission 4 disengages the foot clutch 6 and shifts to the first gear.
When the speed change gear 21 is selected, the power is transmitted only through the first speed change gear 21 without passing through the sub-transmission 3, and the power is transmitted to the second speed or higher speed change gear 22, 23 and 24, power is always transmitted through the high speed or low speed of the auxiliary transmission 3, so there are seven speed ratios in total. One-way clutch 3 of sub-transmission 3
a transmits power from the engine 5 side to the axle 7 side, but has the function of cutting off power transmission from the axle 7 side to the engine 5 side, and its operation is entirely dependent on the force relationship between the load and the transmitted power. In contrast, the hydraulic clutch 3b is intermittently controlled by commands from a control circuit 8 containing a microcomputer.

As shown in FIG. 4, the control circuit 8 includes an AD connected to a throttle opening sensor 9 that detects the throttle opening varied by an accelerator pedal 9a.
A converter 10 or a waveform shaping circuit 12 connected to the vehicle speed sensor 11, a waveform shaping circuit 14 connected to the engine rotation sensor 13, a battery power source 15, etc. are connected, and are used to grasp the running condition of the vehicle. The necessary information can be collected. A microcomputer (not shown) in the control circuit 8
controls the energization of the solenoid 16 for connecting and disconnecting the hydraulic clutch 3b via an amplifier 17 and a solenoid drive circuit 18 so as to obtain power performance suitable for the driving conditions of the vehicle.

In addition, in this example, the vehicle speed sensor 11 is connected to the axle 7.
It consists of a magnetic disk 11a at the end of the rotation transmission shaft 7a connected to the rotary transmission shaft 7a, and a reed switch 11b that opens and closes by the rotation of the magnetic disk 11a.
Further, the engine rotation sensor 13 uses an ignition coil 13b that is energized by a transistor 13a that is turned on in response to an ignition command.

[Problem that the invention seeks to solve]

The conventional vehicle running control device 1 described above includes a control circuit 8
If the microcomputer inside malfunctions for some reason, the hydraulic clutch 3b inside the auxiliary transmission 3
If the clutch is left in a disengaged state, the sub-transmission 3 will only operate in low gears using the one-way clutch 3a, resulting in the problem that engine braking will no longer be effective.

[Means for solving problems]

This invention solves the above problems, and includes a low speed gear that has a one-way clutch that transmits power only in one direction from the engine to the axle, and a high speed gear that has a clutch that is engaged and engaged by commands from a control circuit. A vehicle running control device that has a transmission in which a manual main transmission is connected in series to an auxiliary transmission connected in parallel with the auxiliary transmission, and detects that the accelerator pedal that opens and closes the engine throttle valve is not depressed. An accelerator off detection switch that detects the vehicle speed, a vehicle speed sensor that detects the vehicle speed, and when the vehicle speed sensor and the accelerator off detection switch are connected, and the accelerator is off and the vehicle speed is equal to or higher than the creeping speed,
The gist of the present invention is to include a high-speed gear selection circuit that forcibly switches the sub-transmission to the high-speed gear side regardless of the output of the control circuit.

[Effect]

In this invention, an accelerator-off detection switch detects that the accelerator pedal is not depressed, and if the vehicle speed is at least creeping speed, the auxiliary transmission is switched to high speed where engine braking is effective, regardless of the output of the control circuit. Forcibly switch to the stage side.

〔Example〕

Embodiments of the present invention will be described below with reference to FIGS. 1 and 2. 1 and 2 are a circuit configuration diagram and a signal waveform diagram of each part of the circuit, respectively, showing an embodiment of the vehicle running control device of the present invention. In addition,
In FIG. 1, the same components as those in FIG. 4 are given the same reference numerals.

In FIG. 1, the vehicle running control device 31 detects that the accelerator is off and the vehicle speed is higher than the creeping speed, and sets the high speed gear to forcibly connect the hydraulic clutch 3b in the sub-transmission 3. A selection circuit 32 is provided, and the output of the high-speed stage selection circuit 32 is
It is configured to be supplied to the solenoid drive circuit 18 via the OR gate circuit 33 together with the output of the control circuit 8 .

The high speed gear selection circuit 33 includes an accelerator off detection switch 34 that is provided near the accelerator pedal 9a and closes when the accelerator pedal is not depressed.
The inverter circuit 35 connected to the vehicle speed sensor 11 and the accelerator off detection switch 34 and the vehicle speed determination circuit 36 connected to the vehicle speed sensor 11 are connected to the OR gate circuit 33 via an AND gate circuit 37. The configuration is such that it is connected to one input terminal. The vehicle speed determination circuit 36 is configured such that the speed pulse that is the output of the vehicle speed sensor 11 is connected to a coupling capacitor.
C ₀ and the transistor Q ₁ applied to the base via the voltage dividing circuit 38a, the terminal voltage of the capacitor C ₁ which is short-circuited and discharged during the conduction period of this transistor Q ₁ , and the voltage dividing resistors R1 _a and R1 _b . a first comparison circuit 38 that compares the voltage with a predetermined reference voltage;
The output of this first comparator circuit 38 is the voltage divider circuit 39a.
with transistor _Q2 applied to the base through
The terminal voltage of capacitor C ₂ which is short-circuited and discharged during the conduction period of this transistor Q ₂ and the voltage dividing resistor
The second comparison circuit 39 compares the reference voltages determined by R2 _a and R2 _b , and the output of the second comparison circuit 39 is supplied to one input terminal of the AND gate circuit 37 .

Here, it is assumed that when the driver takes his foot off the accelerator pedal 9a and switches to the brake pedal, the control circuit 8 or the throttle opening sensor 9 is malfunctioning for some reason. In this case, the control circuit 8
Although a normal control operation cannot be expected, the high-speed gear selection circuit 32 detects that the accelerator is off and the vehicle speed exceeds the creeping speed, and automatically switches the sub-transmission 3 to the high-speed gear side.

That is, since the accelerator off detection switch 34 is closed when the accelerator is turned off, the input of the inverter circuit 35 is set to low level, and the high level output shown in FIG. 2F becomes one input of the AND gate circuit 37. When the vehicle speed exceeds the creeping speed, as shown in FIGS. 2A to 2E, the terminal voltage of capacitor _C1 , which is the non-inverting input of the first comparator circuit 38 in the vehicle speed determining circuit 36, is lower than the inverting input. Therefore, due to the low level output of the first comparison circuit 38, the transistor Q ₂ becomes non-conductive.
As a result, the terminal voltage of capacitor C ₂ exceeds the inverting input of the second comparator circuit 39, which causes the second
The high level output of the comparison circuit 39 becomes the other input of the AND gate circuit 37.

Therefore, if the vehicle speed exceeds the creeping speed when the accelerator is turned off, the high level output of the AND gate circuit 37 shown in FIG.
8. Therefore, the solenoid drive circuit 18 de-energizes the solenoid 16, and the hydraulic clutch 3b is connected regardless of the output of the control circuit 8, so that the auxiliary transmission 3 is shifted to the high speed gear where the engine brake is applied. selected.

In this way, when the driver takes his foot off the accelerator pedal in an attempt to decelerate, the vehicle running control device 31 detects this using the accelerator off detection switch 34, and if the vehicle speed is equal to or higher than the creeping speed, Since the auxiliary transmission 3 is forcibly switched to the high speed gear side where engine braking is effective, regardless of the output of the control circuit 8, even if the control circuit 8 malfunctions for some reason, the accelerator can be turned off. At that time, if the vehicle speed exceeds the creeping speed, the system automatically switches to the high speed gear where engine braking is applied, ensuring that engine braking is applied.

〔Effect of the invention〕

As explained above, according to the present invention, when the driver takes his foot off the accelerator pedal, this is detected by the accelerator off detection switch, and if the vehicle speed is equal to or higher than the creeping speed, the control circuit Because the sub-transmission is configured to forcibly switch to a gear position where engine braking is effective, regardless of the output, even if the control circuit malfunctions for some reason, the vehicle speed will return to the creeping speed when the accelerator is released. If it exceeds the limit, the engine will automatically switch to the high speed gear where engine braking is effective, and this will compensate for the unlikely failure of the control circuit.Furthermore, since the accelerator off detection switch detects accelerator off, the throttle This provides excellent effects such as being able to reliably apply engine braking even if the opening sensor or the like fails.

[Brief explanation of the drawing]

1 and 2 are circuit configuration diagrams and signal waveform diagrams of various parts of the circuit, respectively, showing an embodiment of the vehicle travel control device of the present invention, and FIGS. 3 and 4 are examples of conventional vehicle travel control devices, respectively. FIG. 1 is a schematic configuration diagram and a circuit configuration diagram. 2...Main transmission, 3...Sub-transmission, 3a...One-way clutch, 3b...Hydraulic clutch, 4...Transmission device, 8
...control circuit, 11...vehicle speed sensor, 31...vehicle travel control device, 32...high speed gear selection circuit, 34...accelerator off detection switch, 36...vehicle speed discrimination circuit.

Claims (1)

[Claims] 1 A manual transmission is installed in an auxiliary transmission in which a low speed gear that has a one-way clutch that transmits power from the engine to the axle only in one direction, and a high speed gear that has a clutch that is engaged and engaged by commands from the control circuit are connected in parallel. A vehicle running control device that has a transmission in which the main transmission is connected in series, and includes an accelerator off detection switch that detects that the accelerator pedal that opens and closes the engine throttle valve is not depressed, and a vehicle speed sensor that detects the vehicle speed. When this vehicle speed sensor and the accelerator off detection switch are connected, the accelerator is off, and the vehicle speed is at least creeping speed,
A vehicle running control device comprising: a high-speed gear selection circuit that forcibly switches the sub-transmission to a high-speed gear side regardless of the output of the control circuit.