JPH0473030B2 - - 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 to the engine 5 side, and its operation depends entirely on the force relationship between the load and the transmitted power. On the other hand, the hydraulic clutch 3b is controlled intermittently 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 waveform shaping circuit 12 connected to the converter 10 or 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 speed. 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 includes a transmission device in which an auxiliary transmission is connected in parallel with a manual main transmission, and a manual main transmission is connected in series, the throttle opening sensor detecting the throttle opening of the engine, and the vehicle speed. The vehicle speed sensor is connected to the throttle opening sensor, and when the throttle is fully closed,
Further, the present invention is characterized in that a high speed gear selection circuit is provided which connects the clutch independently of the control circuit when the vehicle speed is equal to or higher than the creeping speed.

[Effect]

This invention uses a throttle opening sensor to detect when the throttle valve is fully closed due to the accelerator being turned off, and when the vehicle speed is equal to or higher than the creeping speed,
To forcibly switch an auxiliary transmission to a high speed gear side where engine braking is effective, regardless of the output of a control circuit.

〔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 stage selection circuit 32 is connected to the throttle opening sensor 9 and the vehicle speed sensor 11, and is connected to a comparison circuit 35 for detecting accelerator off, which is connected to the throttle opening sensor 9, and to the vehicle speed sensor 11. The vehicle speed determination circuit 36 is connected to one input terminal of the OR gate 33 via an AND gate circuit 37. Vehicle speed discrimination circuit 36
The vehicle speed pulse which is the output of the vehicle speed sensor 11 is
The voltage applied to the base of the transistor Q ₁ via the coupling capacitor C _O and 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 R _1a and R _1b , a transistor Q 2 to which the output of the first comparison circuit 38 is applied to the base via a voltage dividing circuit 39a, and a transistor _{Q 2} The terminal voltage of capacitor C ₂ which is short-circuited and discharges during the conduction period of and
It consists of a second comparison circuit 39 that compares the reference voltage determined by voltage dividing resistors R _2a and R _2b , and the output of the second comparison circuit 39 is supplied to one input terminal of the AND gate circuit 37.

Here, suppose that when the driver takes his foot off the accelerator pedal 9a and switches to the brake pedal, the control circuit 8 has caused a malfunction for some reason. In this case, normal control operation by the control circuit 8 cannot be expected, but the high speed gear selection circuit 32 detects that the accelerator is off (throttle opening is zero) and that the vehicle speed exceeds the creeping speed, and automatically shifts to the sub-shift. Switch gear 3 to the high speed side.

That is, as the accelerator is turned off, the output of the throttle opening sensor 9 decreases, and the output of the comparator circuit 35 becomes high level as shown in FIG. 2F.
One input of the AND gate circuit 37 becomes high level. 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 the capacitor C ₂ exceeds the inverting input of the second comparator circuit 39, so that the high level output of the second comparator 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 released, the high level output of the AND gate circuit 37 shown in FIG.
and is supplied to the solenoid drive circuit 18 via the amplifier 17. Therefore, the solenoid drive circuit 18
As a result, the solenoid 16 is de-energized and the hydraulic clutch 3b is connected regardless of the output of the control circuit 8, so that the auxiliary transmission 3 selects a high speed gear where engine braking is effective.

In this way, the vehicle running control device 31 detects, by the throttle opening sensor 9, that the throttle valve is fully closed due to the accelerator being turned off, and when the vehicle speed is equal to or higher than the creeping speed, the control circuit 8 outputs the Since the sub-transmission 3 is configured to be forcibly switched to the high-speed gear side where engine braking is effective, regardless of the engine brake, even if the control circuit 8 malfunctions for some reason, the vehicle speed will slow down when the accelerator is released. If the speed is exceeded, the engine automatically switches to the high speed gear where engine braking is effective, thereby compensating for any unexpected failure of the control circuit 8.Furthermore, the throttle opening sensor 9 detects accelerator off. Therefore, there is no need for a special switch or the like to detect when the accelerator is off.

〔Effect of the invention〕

As explained above, according to the present invention, when the throttle opening sensor detects that the throttle valve is fully closed due to the accelerator being turned off, and the vehicle speed is equal to or higher than the creeping speed, the output of the control circuit is The configuration is such that the auxiliary transmission is forcibly switched to the gear position where engine braking is effective, so even if the control circuit malfunctions for some reason, the vehicle speed will still change 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 any unexpected failure of the control circuit.Furthermore, since the throttle opening sensor detects accelerator off, the accelerator will This provides excellent effects such as no need for a special switch or the like to detect the off state.

[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, 8... Control circuit, 9... Throttle opening sensor, 11... Vehicle speed sensor, 31...Vehicle travel control device, 32...High speed selection circuit, 36...Vehicle speed determination 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 having a transmission in which a main transmission is connected in series, comprising: a throttle opening sensor for detecting the throttle opening of an engine; a vehicle speed sensor for detecting vehicle speed; With the sensor connected and the throttle fully closed,
A vehicle running control device further comprising: a high speed gear selection circuit that connects the clutch independently of the control circuit when the vehicle speed is equal to or higher than the creeping speed.