JPH0520598Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) This invention relates to improvement of an automatic transmission for a vehicle.

(Prior Art) In recent years, in order to reduce driver fatigue, an increasing number of vehicles are equipped with automatic transmissions that automatically change gears by interposing a torque converter between the engine and the transmission. Since the torque converter is a fluid coupling, the output transmission efficiency is inevitably lower than that of a mechanical clutch, which is disadvantageous in terms of improving fuel efficiency.

Therefore, in order to improve fuel efficiency as well as ease of operation, the applicant has proposed an automatic transmission that uses a conventional transmission and a mechanical clutch, and automatically performs gear shifting through electronic control rather than the driver operating the clutch or transmission (see, for example, Japanese Utility Model Application No. 60-44579).

FIG. 6 is a flowchart showing the control operation, and the basic operation is the same as the operation of an automatic transmission using a torque converter.

In addition, the transmission employs a synchronized mesh mechanism that quickly matches the rotational speeds of the gears that engage, but basically the gears that engage are aligned within a predetermined relative rotational speed difference range (synchronizable range). If they can be accommodated, they can be meshed without causing gear noise, etc., even without a synchronized mesh mechanism.

Therefore, in order to reduce costs, this device omit the synchronized mesh mechanism, which has a complicated structure, and detects the rotational speed of the gears to be meshed, and sets the gears when the two reach the synchronized range (synchronized range). I'm letting it happen.

For example, when shifting up while driving, the 7th
As shown in the diagram, if it is determined that a shift is necessary, the fuel injection pump control lever is returned to the no-load position at steps 20 to 22, and at the same time the mechanical clutch is disengaged and the transmission is set to the neutral position. . Incidentally, FIG. 7 is a flowchart showing the operation of the shift-up and shift-down control performed in step 8 and step 9 of FIG. 6.

After that, connect the clutch immediately at 23. In manual shifting, it is normal to engage the clutch after completing a gear shift, but in order to reduce shift shock and further shorten the time required for shifting, the clutch is connected at any time other than when the transmission is set to the neutral position. The clutch is connected to the engine output shaft.

In step 24, the gear rotation speed Ng of the main gear rotating freely on the main shaft is detected, and if Ng is greater than Nsyc, the process proceeds to step 25. Here, Nsyc is the rotation speed of the main shaft connected to the rear axle. If Ng≦Nsyc+ΔN in step 25, it is determined that Ng is in the synchronous region, and in step 26, gear setting is started to mesh the main gear with the main shaft, and after the gear setting is completed, the control lever is returned to its original position in step 27. Also, if Nsyc is detected in step 24, the process proceeds to step 25.
If Nsyc≧Ng, the accelerator is fully opened once in step 28, and after waiting until Nsyc<Ng in step 29, the accelerator is fully closed in step 30. Then, the process proceeds to step 25.

Here, ΔN is an allowable range set as a range in which synchronous meshing can be achieved with respect to Nsyc without causing gear noise, and Nsyc+ΔN gives the upper limit value of the synchronization range.

(Problem to be Solved by the Invention) Incidentally, in such an automatic transmission device, the operation of the clutch disengaging means for disengaging and disengaging the clutch is controlled by a clutch ON switch, which operates when the clutch is engaged, and a clutch ON switch, which similarly operates when the clutch is disengaged. clutch to do
OFF switches are used to detect this, but for this reason, if a failure occurs in these position switches, it becomes impossible to determine the clutch engagement state even if the clutch engagement means is normal, and there is a concern that control may be interrupted. Ta.

(Means for solving the problem) In order to solve this problem, this invention
As shown in Fig. 1, a clutch disengagement means for disengaging and disengaging the mechanical clutch, a gear shift means for shifting gears of the transmission, an engine rotation control means for controlling engine rotation, and a determination system that determines whether the transmission has entered a gear shift range. In an automatic transmission system for a vehicle, the clutch is turned ON when the clutch is in the engaged position.
A clutch OFF switch that operates at the disconnection position of the switch and clutch, and an actuator and clutch that drive the clutch based on these output signals.
A failure determination means for determining failure of the ON switch and clutch OFF switch is provided. The failure determination means includes a determination table corresponding to the direction of operation of the clutch, and determines, based on comparison with the determination table selected according to the direction of operation, if the output of each of the switches is reversed with respect to the normal state. actuator error,
The configuration is such that a switch error is determined when the outputs of each switch are both on or both off.

(Operation) Since the failure of the clutch ON switch and clutch OFF switch can be determined by the failure determination means,
Even when these position switches fail, continuous control of gear shift operation is possible by switching to backup control.

In addition, since it is equipped with a judgment table according to the direction of clutch operation, it is possible to detect an abnormal state in which the output of the clutch ON switch and clutch OFF switch is reversed with respect to the direction in which the actuator that drives the clutch should operate. This enables failure determination of the clutch actuator.

(Example) Figure 2A is a schematic diagram showing the mechanical configuration of an embodiment of this invention applied to a diesel engine.
The figure is also a block configuration diagram. In this example,
The fuel injection pump 41, mechanical clutch 42, and transmission 43 are provided with various detection means for detecting their operating states and actuators for driving them, and a controller composed of a microcomputer is provided based on signals from these detection means. The unit 60 controls the actuator to achieve automatic gear shifting.

First, a means for detecting the operating state is required as a detection means, and this operating state is determined by the engine load,
This can be determined from the position of the select lever, the engagement/disengagement state of the clutch, the actual shift position of the transmission, and the vehicle speed. For this reason,
An accelerator sensor 50 that detects the depression angle (accelerator opening degree) of the accelerator pedal 45 as an engine load is attached to the accelerator pedal 45 .
8 includes a selector position sensor 51 that detects the position of the select lever (selector) 49, and the mechanical clutch 42 includes a clutch position sensor 54A that detects the disengaged state of the clutch and a clutch ON switch 54A that operates when the clutch is engaged. Clutch OFF switch 54B operates in the disconnected position as well.
However, the transmission 43 without a synchronized mesh mechanism includes a shift position sensor 58 that detects the actual shift position and a main shaft rotation sensor that detects the rotation speed of the main shaft connected to the rear axle via the propeller shaft 44. 56
are provided respectively. Note that since the main shaft rotation speed is proportional to the vehicle speed, the main shaft rotation speed sensor 56 functions as a vehicle speed sensor.
In addition, synchronization of the gears to be meshed is achieved by driving the gear shift mechanism when the rotational speed Ng of the main gear idly rotating on the main shaft enters the synchronization range established with respect to the rotational speed Nsyc of the main shaft, so the main gear rotational speed It is necessary to detect Ng. In this case, the main gear is in synchronous mesh with the countershaft that transmits the engine output, so
The rotational speed of the countershaft is also the rotational speed Ng of the main gear, and therefore a countershaft rotation sensor 57 is provided.

Next, for these detection means, the fuel injection pump 41 is an actuator that is controlled by the control unit 60, and is equipped with a control lever to drive the control lever according to the request and to match the engine rotation with the requested rotation. A governor control device 53 that controls engine rotation is connected to the clutch 42.
The transmission 43 is provided with a clutch actuator 55 that engages and engages the clutch, and a gear shift actuator 59 that drives the gear shift mechanism and sets a gear shift.

The control unit 60 that controls these actuators is comprised of a synchro determination circuit 62, a transmission control circuit 64, an engine control circuit 63, a clutch engagement control circuit 65, a shift change control circuit 61, etc., which constitute a gear change operation control means. ing.

Here, the synchronization determination circuit 62 determines, based on the rotation speed signals from the main shaft rotation sensor 56 and the countershaft circuit sensor 57, a rotation speed range that is higher or lower than the main shaft rotation speed Nsyc by a predetermined value as a synchronizable region.

The shift change control circuit 61 also includes an accelerator opening sensor 50 as a driving state detection means and a main shaft rotation sensor 5 as a vehicle speed detection means.
Based on the signal from 6 and the signal from the synchronization determination circuit 62, the control circuits 63 to 6
A shift control signal is output to 6. As before, this control signal operates the governor control device 53 and clutch actuator 55 to decrease and increase the engine speed, disconnect and connect the clutch, and shift the gear to a predetermined gear position.

In this example, the clutch pedal 46 is installed so that only the clutch operation at the time of starting can be performed manually.
A clutch pedal switch 67 that detects whether the accelerator pedal 45 is depressed, and a switching device 68 that directly transmits the accelerator opening degree of the accelerator pedal 45 to the control lever of the fuel injection pump 41 are provided. 69 is a transmission position lamp that indicates the actual shift position, 98 is a switch error lamp that indicates an error in clutch ON/OFF switches 54A, 54B, and 99 is a clutch actuator 55.
Actuator error lamp indicating an error.

In this case, the clutch actuator is constructed as shown in FIG. 2B, and it is the clutch booster 70, which is an air-hydraulic device, that directly drives the clutch disk to disengage the clutch.

During automatic clutch operation, the air pressure that drives this booster 70 is switched and controlled by the clutch disconnection valve 55A, and the air release flow rate is controlled by the flow rate control valve 55.
Controlled by B.

For example, when the clutch is disengaged, the clutch switching valve 55
Due to the ON signal to
0, the rod 71 extends to the left in the figure against the return spring, and the clutch disk is separated from the flywheel via the clutch lever 72.

Also, when the clutch is connected, the clutch switching valve 55
The OFF signal to A cuts off the air supply from the air reservoir 76 and releases the air in the booster 70 to the atmosphere, so the rod 71 is driven to the right in the figure by the return spring, and the clutch disk is pressed against the flywheel. be done.

Note that when manually disengaging the clutch at the time of starting, the clutch pedal 46 is depressed and the hydraulic pressure of the master cylinder (hydraulic cylinder) 78 connected to the clutch pedal 46 is guided to the control valve section 79 of the booster 70. The control valve section 79 opens. Therefore, the air pressure is now transferred to the double check valve 80 via the second air pressure passage 77B and the control valve section 79.
, the valve body 80A of the valve 80 moves to the right in the figure to block the first pneumatic passage 77A and communicate with the second pneumatic passage 77B. This drives the rod 71 to the left in the figure and disengages the clutch. When the clutch is connected, the control valve section 79 controls the clutch pedal 46.
Since the clutch stroke is proportional to the amount of depression of the clutch, the driver can connect the clutch as desired.

Furthermore, by depressing the clutch pedal 46,
The clutch pedal switch 67 is turned on, and this signal gives priority to manual clutch operation over automatic clutch operation.

On the other hand, the previously described control unit 60 has a failure judgment table (FIG. 4B) preset as described later based on the output signals of the clutch ON switch 54A and the clutch OFF switch 54B.
Fig. 4A shows the judgment table when the clutch is engaged, and Fig. 4A shows the judgment table when the clutch is disengaged.
4A, 54B and a failure determination circuit 93 for determining failure of the clutch booster 70;
Backup circuit 9 that controls shift change operation by making full use of other signals when 54B fails.
4 is provided.

FIGS. 5A and 5B are flowcharts illustrating the operation of the automatic clutch operation performed by the control unit 60 (clutch engagement control performed in steps 21 and 23 in FIG. 7), and based on this flowchart, The operation of this embodiment will be explained. The symbols in the figure indicate processing numbers.

When the clutch is disengaged as shown in FIG. 5A, when a clutch disengagement request occurs, the clutch disengagement valve 55
Outputs ON signal to A. And clutch ON
Switch 54A and clutch OFF switch 54
Based on the ON-OFF signal from B and according to the failure judgment table in Fig. 4A, it is first judged in step 102 whether or not the clutch has been disengaged, that is, whether or not it corresponds to the case marked with ○ in the judgment table. If NO, after the specified time (for example, 1 second) has passed, the clutch is turned on again at 104.
Determine whether the OFF switches 54A, 54B are out of order.
When the clutch ON/OFF switches 54A, 54B are out of order, that is, in the case of △ in the judgment table, the switch error lamp 98 is turned on in step 105, and the shift change control is continuously executed.

On the other hand, when 104 is NO, that is, when the clutch booster malfunctions and corresponds to the case of × in the judgment table, the clutch disconnect valve 55A is activated at 106 and 107.
It outputs an OFF signal, lights up the clutch actuator error lamp 99, and interrupts subsequent shift change control.

Further, when the clutch is connected as shown in FIG. 5B, when a clutch connection request occurs, an OFF signal is output to the clutch disconnection valve 55A at step 110. And from clutch ON, OFF switch 54A, 54B
Based on the ON and OFF signals, it is first determined in step 111 whether the clutch is connected or not, according to the failure judgment table shown in FIG. If NO, after the specified time (for example, 1 second) has passed, the clutch is turned on again with 113.
Determine whether the OFF switches 54A, 54B are out of order.

When the clutch ON and OFF switches 54A and 54B are in failure, that is, when it corresponds to the case marked △ in the judgment table, the switch error lamp 98 is lit at step 114, and the shift change control is continued.
If 113 is NO, that is, if the clutch booster is malfunctioning and corresponds to the case marked with × in the judgment table,
Clutch actuator error lamp 98 at 115
lights up and interrupts subsequent shift change control.

In this way, the control unit 60 has a failure determination system for determining whether a failure occurs in the clutch ON/OFF switches 54A, 54B and the clutch booster 70 according to a failure determination table set in advance based on these output signals. The circuit 93 is provided so that even if the switches 54A and 54B fail, the backup circuit 94 can continue to control the shift change operation without interruption by making full use of other signals, thereby increasing the reliability of the control system. improves.

(Effect of the invention) In summary, according to this invention, the clutch
Since it is now possible to determine whether the ON switch or clutch OFF switch is malfunctioning, it is possible to continue controlling the gear shift operation without interruption even in the event of a malfunction of these switches, which improves the reliability of the control system. is obtained. In addition, it is possible to determine whether there is an abnormality in the clutch actuator from the output status of each switch according to the direction of clutch operation, so it is possible to more accurately identify abnormal conditions in the automatic transmission, not just a simple switch failure. It also has the effect of giving a warning.

[Brief explanation of the drawing]

Figure 1 is an overall configuration diagram to clearly show the configuration of this invention, Figure 2A is a schematic diagram explaining the mechanical configuration of an embodiment of this invention, and Figure 2B is the main part configuration of the clutch operation mechanism. 3 is a block configuration diagram, FIG. 4 is a failure judgment table when the clutch is disengaged, FIG. 4B is a failure judgment table when the clutch is connected, and FIGS. 3 is a flowchart illustrating an example of a control operation performed. 6th
FIG. 7 is a flowchart explaining the operation in the preceding order. 41... Fuel injection pump, 42... Mechanical clutch, 43... Transmission, 45... Accelerator pedal, 46... Clutch pedal, 49...
...Select lever (selector), 51...Selector position sensor, 53...Governor control device, 54A
...Clutch ON switch, 54B...Clutch
OFF switch, 56... Main shaft rotation sensor, 57... Counter shaft rotation sensor, 6
0...Control unit, 61...Shift change control circuit, 62...Synchronization determination circuit, 6
3... Engine control circuit, 64... Transmission control circuit, 65... Clutch intermittent control circuit, 67... Clutch pedal switch, 70...
Clutch booster, 93... Failure determination circuit, 94
...backup circuit.

Claims (1)

[Scope of utility model registration request] A clutch disengagement means for disengaging and disengaging a mechanical clutch, a gear shift means for shifting gears of a transmission, an engine rotation control means for controlling engine rotation, a shift determination means for determining that the shift range has been entered, and a determination signal for this determination. In the automatic transmission system for a vehicle, the automatic transmission is equipped with a gear shift operation control means that reduces or increases the engine rotation and shifts the gear to a predetermined gear position based on the clutch, and a clutch ON switch that operates when the clutch is engaged, and a clutch ON switch that operates when the clutch is disengaged. clutch OFF switch,
The actuator that drives the clutch, the clutch ON switch, and the clutch OFF switch have a failure determination means that determines failure of the clutch based on these output signals, and the failure determination means is provided with a determination table corresponding to the direction of operation of the clutch. Based on the comparison with the judgment table selected according to the operating direction, an actuator error occurs if the output of each switch is reversed from the normal state, and an actuator error occurs if the output of each switch is both on or both off. An automatic transmission device for a vehicle, characterized in that it is configured to determine a switch error.