JPH0570021B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a propeller shaft rotation speed detection device in an automatic transmission.

[Prior Art] The rotation of an automobile engine is transmitted to a propeller shaft that is decelerated to a required rotation speed, and the transmission is what performs the deceleration operation.

The transmission is equipped with a plurality of gears each having a different number of teeth on the countershaft and output shaft, and by selecting the engagement between the countershaft gear and the output shaft gear, the required reduction ratio can be set. It is becoming possible to obtain it.

Conventionally, this selection operation (shift operation) is performed by the driver by operating a shift operation lever accompanied by a clutch operation in accordance with the driving condition. Therefore, the driving operation was very complicated.

Under these circumstances, automatic transmissions have been increasingly adopted in practical vehicles such as trucks in recent years.

This automatic transmission uses a control device such as a microcomputer to calculate and select the most suitable gear position for the driving condition according to the vehicle speed, accelerator opening degree, etc., and then drives the actuator to operate the clutch and shift the gear to the aforementioned gear position. The gears are meshed so that By adopting an automatic transmission, there is almost no need for the driver to change gears, and the burden on the driver is greatly reduced.

However, detection of the rotation speed of the propeller shaft is essential for automatic gear shifting operations in such automatic transmissions, and if rotation speed detection becomes impossible, engine rotation adjustment during gear shifting will not be possible. It becomes impossible to shift gears.

[Problems to be Solved by the Invention] As mentioned above, if there is a problem in detecting the rotational speed of the propeller shaft, automatic gear shifting will not be possible and the vehicle will stop. , which is extremely inconvenient when there is an emergency.

Therefore, in the present invention, even if the propeller shaft rotation sensor provided for the automatic transmission fails, the sensor provided for other purposes, such as the vehicle speed sensor for auto cruise or vehicle speed sensitive power steering, can be used. The aim is to avoid a situation where the automatic transmission becomes inoperable by reusing the signals from the automatic transmission.

[Means for Solving the Problems] The present invention determines the running state of the vehicle based on vehicle speed, engine speed, accelerator operation amount, etc., selects the gears to be engaged with the transmission, and selects the gears to be engaged with the clutch actuator. In an automatic transmission that drives a gear change actuator to achieve a desired deceleration state, an engine rotation sensor detects the rotation speed of the engine, a propeller shaft rotation sensor detects the rotation speed of the propeller shaft, and , another sensor that detects the rotation speed of the propeller shaft; a switching circuit that outputs one of the detection results of the propeller shaft rotation sensor and the other sensor; and the propeller shaft rotation sensor. a quality determination device that determines whether or not the detection result is normal and outputs the quality determination result; and a propeller shaft rotation based on the signal from the engine rotation sensor and the quality determination result from the quality determination device. The sensor is determined to be abnormal, and when the propeller shaft rotation sensor is normal, the detection result from the propeller shaft rotation sensor is input through a switching circuit that is switched to the propeller shaft rotation sensor side, and based on the detection result. While outputting a drive signal to the clutch actuator and the speed change actuator, when an abnormality in the propeller shaft rotation sensor is detected, the switching circuit is switched to the other sensor side,
The detection result from the other sensor is input,
The present invention is characterized by comprising a microcomputer that outputs a drive signal to the clutch actuator and the shift actuator based on the detection result.

[Operation] When there is no abnormality in the propeller shaft rotation sensor, the microcomputer outputs a drive signal to the clutch actuator and the gear shift actuator based on the detection result of the sensor, and the gear shift operation of the transmission is performed. When an abnormality is detected in the propeller shaft rotation sensor, the switching circuit is switched by the microcomputer, the detection result from the other sensor is input to the microcomputer, and the microcomputer uses the detection result from the other sensor to input the switching circuit. A drive signal is output from the clutch actuator and the shift actuator to perform the shift operation of the transmission.

[Example] Hereinafter, one example of the present invention will be described with reference to the drawings.

The figure shows an automatic transmission equipped with a propeller shaft rotation speed detection device according to an embodiment of the present invention.

In the figure, 1 is an engine, 2 is a transmission connected to the engine 1 via a clutch 3, 4 is a transmission output shaft, and 5 is a propeller shaft. The transmission 2 is equipped with a gear change actuator 6. The clutch 3 is provided with a clutch actuator 7 for connecting and disconnecting the clutch.

A propeller shaft rotation sensor 9 is provided facing the rotating plate 8 provided on the output shaft of the transmission 2, and a vehicle speed sensor 10 is provided on the side of the transmission 2 to detect the vehicle speed based on the rotation speed on the output side of the transmission. establish. The engine 1 also includes an engine rotation sensor 1 that detects the engine rotation speed.
1 will be provided.

The output signal of the propeller shaft rotation sensor 9 is inputted to a first counter 12 and a level determination device 15, and the signal from the vehicle speed sensor 10 is used for auto cruise control etc. (not shown) and is input to a second counter 13 and level determination device. 16.
Voltage level values 17 and 18, which serve as standards for determining acceptability, are set and input to both level determiners 15 and 16.

The first and second counters 12 and 13 are connected to a microcomputer 20 via a switching circuit 19, and the level determiners 15 and 16 are connected to the microcomputer 20. Further, the output of the engine rotation sensor 11 is input to a third counter 14, and the third counter 14 is connected to the microcomputer 2.
Connect to 0. Furthermore, a clutch sensor 21 provided on the clutch actuator 7 is connected to the microcomputer 20, and a controller 23 which issues a gear change command signal depending on the position of the gear change lever 22 is connected.

A drive signal is outputted to the speed change actuator 6 and clutch actuator 7 based on the calculation results in the microcomputer 20, and a switching signal is outputted to the switching circuit 19, and a fault indicator 24 is outputted to the switching circuit 19.
An alarm signal is output for each.

The propeller shaft rotation speed detection device according to the present invention includes a propeller shaft rotation sensor 9, a vehicle speed sensor 10, an engine rotation sensor 11,
The device includes first, second and third counters 12, 13, 14, level determiners 15, 16, switching circuit 19, etc., and the operation of this device will be explained together with the operation of the automatic transmission.

First, the signal from the engine rotation sensor 11 is
Microcomputer 20 via counter 14
is input, and the microcomputer 20 confirms that the engine 1 is rotating.

Next, when the gear shift lever 22 is operated, a signal instructing either forward or backward movement is input from the controller 23 to the microcomputer 20, and the clutch actuator 7 is actuated based on the signal from the controller 23.
is driven, and when the drive is confirmed by the clutch sensor 21, the shift actuator 6 is driven so as to mesh with the low gear if the vehicle is moving forward, and the shift actuator 6 is in a standby state.

Next, when the accelerator (not shown) is depressed, the amount of depression is input to the microcomputer 20, and the microcomputer changes the speed of the transmission 2 in an increased speed state.

As the speed of the engine increases, the rotational speed of the transmission output shaft 4 also increases, and signals are output from the propeller shaft rotation sensor 9 and the vehicle speed sensor 10 due to the rotation of the transmission output shaft 4. The output levels of the signals from both sensors 9 and 10 are determined by level determiners 15 and 16, and the determination results are input to the microcomputer 20. In the microcomputer 20, the engine rotation sensor 1
The signal from 1 and the level determination result are compared to determine whether both sensors 9 and 10 are operating normally.

When it is confirmed that at least the propeller shaft rotation sensor 9 is operating normally, a signal is sent to the switching circuit 19 and the first counter 1 is activated.
2 and the microcomputer 20 are connected.

The number of revolutions of the propeller shaft is determined by the first counter 12.
is input to the microcomputer 20, and the microcomputer 20 follows a preset and input program to the clutch actuator 7 and the shift actuator 6 when the shift timing in the speed increase state and the input rotation speed match. A drive signal is issued to perform a speed change operation of the transmission 2.

Further, the gear shifting operation of the transmission in the deceleration state is performed in the same manner.

Next, if for some reason the propeller shaft rotation sensor 9 stops emitting a signal or a signal at the required level does not come out, the microcomputer 20 detects such an abnormality using the judgment signal from the level judger 15, A switching signal is issued to the switching circuit 19, the second counter 13 and the microcomputer 20 are connected, and the microcomputer 20
A signal from the vehicle speed sensor 10 is input to the .

Therefore, even if the propeller shaft rotation sensor 9 should fail, the vehicle can be operated without any problem. When a failure is detected in the propeller shaft rotation sensor 9, an alarm signal is input to the failure indicator 24, a predetermined alarm lamp is turned on, and the driver is notified of the abnormality in the propeller shaft rotation sensor 9. This fault indicator 2
The display 4 allows the driver to take the vehicle to a maintenance shop at the required time to repair the failure of the propeller shaft rotation sensor 9.

If, unfortunately, the vehicle speed sensor 10 also fails while the propeller shaft rotation sensor 9 is out of order, this failure will cause the level determiner 16 and the engine rotation sensor 1 to fail.
The microcomputer 20 performs the necessary processing to stop the vehicle to ensure safety.

In this case as well, it is convenient for the driver to know the cause of the stoppage by displaying the failure of the vehicle speed sensor 10 on the failure indicator 24.

Although the above embodiment uses a vehicle speed sensor as the second sensor for detecting the propeller shaft rotation speed, it goes without saying that a separate sensor may be provided.

[Effects of the Invention] As described above, according to the present invention, even if the propeller shaft rotation sensor should fail, the vehicle can run without any trouble, the inconvenience of stopping the vehicle can be avoided, and the reliability of the vehicle itself can be improved. Demonstrates the excellent effect of obtaining.

[Brief explanation of drawings]

The figure is a block diagram showing one embodiment of the present invention. 2 is a transmission, 6 is a gear change actuator, 7 is a clutch actuator, 9 is a propeller shaft rotation sensor, 10 is a vehicle speed sensor, 1
5 and 16 are level determiners, 19 is a switching circuit, and 20 is a microcomputer.

Claims (1)

[Scope of Claims] 1. The driving state of the vehicle is judged based on the vehicle speed, engine rotation speed, accelerator operation amount, etc., the gears to be engaged with the transmission are selected, and the clutch actuator and the shift actuator are driven. In the automatic transmission, which is designed to achieve the required deceleration state, an engine rotation sensor detects the engine rotation speed, a propeller shaft rotation sensor detects the propeller shaft rotation speed, and another sensor for detection; a switching circuit that outputs one of the detection results of the propeller shaft rotation sensor and the other sensor; and the detection result of the propeller shaft rotation sensor is normal. a pass/fail determiner that determines whether or not the quality is the same and outputs the pass/fail determination result; and determines whether the propeller shaft rotation sensor is abnormal based on the signal from the engine rotation sensor and the pass/fail determination result from the accept/fail determiner; When the propeller shaft rotation sensor is normal, the detection result from the propeller shaft rotation sensor is input through the switching circuit switched to the propeller shaft rotation sensor side, and based on the detection result, the clutch actuator and gear shift control are input. While outputting a drive signal to the actuator, when an abnormality is detected in the propeller shaft rotation sensor, switching the switching circuit to the other sensor side,
The detection result from the other sensor is input,
A propeller shaft rotation speed detection device in an automatic transmission, comprising: a microcomputer that outputs a drive signal for the clutch actuator to a gear shift actuator based on the detection result.