JPH058379Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to an automatic transmission for a vehicle, which is called a so-called semi-automatic system, and particularly relates to an automatic transmission for a vehicle that has measures against failure of the transmission actuator. .

[Prior Art] In an automatic transmission of a so-called semi-automatic system, if a manual operation is performed at the time of starting, then a control device judges the running state of the vehicle, such as the vehicle speed, engine load, or accelerator opening, and performs the specified operation. Various types have been proposed because they are relatively easy to operate and consume little fuel. In such a semi-automatic system, the shift change actuator of the transmission is actuated by a signal from the control device, and its operating position is fed back to the control device by a position switch, so that the control device selects the correct shift gear. It is designed to confirm that a gear has been input. As an example of such a technique, as proposed in Utility Application No. 108817/1983 by the present applicant, a plurality of shift forks are fitted to one shift shaft, and the fork to be used is selected. The actuator is activated to move the shaft and the fork to engage the gear. An example of such a transmission is shown in FIG. 3, in which a shift shaft 2 extending longitudinally in a housing 1 of the transmission is fitted with a plurality (three in the illustrated example) of shift forks 3a, 3b, 3c. A known shift actuator 35 including a piston operated by fluid pressure is provided at one end, and a shift position switch 3 constituting a shift position sensor is provided at the other end.
4a, 34b, and 34c are provided.

On the other hand, the housing 1 has select actuators 4a, 4b, 4c corresponding to the number of shift forks.
are provided, and these have substantially the same configuration, and by supplying fluid pressure to the upper side of the piston 6 in the cylinder 5 from a fluid pressure source (not shown),
The piston rod 7 pushes the lock pin 8 into the shift shaft to unite the selected shift fork (shift fork 3b in the illustrated example) with the shift shaft 2, and the selected shift fork is moved by the shift actuator 35. It is something. In the figure, 9a and 9b are select position switches used in the present invention as described later.

In such a transmission, the shift position switch 34b provided at the center is a switch that indicates when the vehicle is in neutral, and this neutral switch always generates a signal when the vehicle is stopped or when a shift change is being performed. Therefore, if the neutral switch 34b were to fail, there would be a problem in that the control device would not be able to determine the subsequent operation because no signal indicating that the transmission had become neutral would be generated.

Furthermore, for example, Japanese Patent Application Laid-Open No. 58-161622 discloses a control device that determines that the transmission is in the neutral state even if the neutral switch is off, if all shift switches are off.
However, such known technology prevents error detection in the case of a so-called half-neutral state, and if the position switch itself fails, it will malfunction.

[Problem to be Solved] Therefore, the purpose of the present invention is to be able to determine the failure when the neutral switch malfunctions,
An object of the present invention is to provide an automatic transmission for a vehicle having a control device that can continue control.

[Means for Solving the Problems] According to the present invention, one shift shaft operated by a shift actuator is provided with a shift position switch for detecting its position, and one shift fork of a plurality of shift forks is further provided with a shift position switch for detecting the position of the shift shaft. In a vehicle automatic transmission system equipped with a select actuator that is integrated into a shift shaft, a sensor that detects the operating position of the select actuator and a neutral switch that detects that the shift shaft is in a neutral position are used. and a control having an error determination means for emitting a signal when the neutral switch does not emit a signal due to a failure of the shift position detection sensor and the sensor of the select actuator emit a signal even when the shift shaft is in the neutral position. The control device is configured to continue the gear shifting operation when all select actuator sensors have returned to the non-select position even if a signal indicating that the shift shaft is in the neutral position is not established. ing.

[Operations and Effects of the Invention] When performing a shift change, the shift shaft always passes through the neutral position, so the neutral switch among the shift position switches always outputs a signal. In the unlikely event that the neutral switch is malfunctioning, no signal will be output, but if the actuator of the select actuator (the piston rod in the embodiment shown in Figure 3) returns to its original position (in the upper position in Figure 3) Even if no signal is generated from the neutral switch, the control device determines that the neutral position has been passed, lights up a lamp indicating an error in the switch, notifies the driver, and continues control. Therefore, subsequent operations can be performed without any problems. Therefore, the vehicle will not stop on the road due to a failure of only the neutral switch.

[Examples] Examples of the present invention will be described below with reference to the drawings. In FIG. 1, a transmission 30 is attached to an engine 10 via a mechanical clutch 20, and its output shaft is connected via a propeller shaft 31 to a rear axle (not shown).

The engine 10 includes a rack drive device 12 for controlling the position of the rack 11a of the fuel injection pump 11.
and an engine rotation sensor 13 are provided.

The clutch 20 is provided with a clutch position sensor 21 for detecting the engaged state of the clutch, and a clutch actuator 22 for connecting and disconnecting the clutch.

The transmission 30 includes a counter shaft rotation sensor 32 that detects the rotation speed of the main gear, and a vehicle speed sensor 3 that detects the rotation speed of the main shaft.
3, and a shift position sensor 34 that detects the shift position of the transmission (switches 34a, 34b,
34c), and a shift change actuator 3 for shifting the transmission.
5 is provided. In addition, select sensor 9
(Select switches 9a and 9b shown in FIG. 3 are representative) are also provided.

On the other hand, a selector 40 provided in a driver's cab (not shown) uses a selector lever 40a to reverse R, 1
Six ranges from speed to 6th speed and neutral N can be specified, and there is a switch inside that corresponds to each range. 41 is a clutch pedal, 42 is a clutch pedal sensor, 43 is an accelerator pedal, and 44 is a sensor for detecting the opening degree of the accelerator. and,
These sensor devices and actuators 12, 1
3, 21, 22, 32, 33, 34, 35, 4
0, 42, and 44 are connected to the control device 50.

The control device 50 determines whether or not to change the shift based on detection signals from the vehicle speed sensor 33, the accelerator pedal sensor 44, and the shift position sensor 34, and also controls the accelerator pedal sensor 44 and the vehicle speed sensor 33, that is, the operation of the vehicle. The gear change operation of the transmission 30 and the engagement/disengagement operation of the clutch 20 are performed based on the detection signal from the state detection means.

According to the present invention, shift shaft 2 (third
) is in the neutral position (switch 34 in Figure 3).
If the switch 34b does not emit a signal even if the switch 34b is in the position where the switch 34b detects If the switch 9a issues a signal, the error determining means 51 of the control device issues a signal and the error lamp 52 is turned on.

Next, the operation of the present invention will be explained mainly with reference to FIGS. 2a and 2b.

FIG. 2a shows an overview of the operation of a conventional control device. First, when starting, that is, when a request for shift operation is issued depending on the driving condition of the vehicle, the control device 50 operates the shift actuator 35. Move the shift shaft to the neutral position (step S1). The controller confirms that the switch 34b has been set to the neutral position by a signal from the switch 34b. Next, a predetermined select actuator (one of 4a, 4b, and 4c) is operated to perform a select set (step S2), and the control device determines that it has been set based on the signal from switch 9b. do. Then, the shift actuator 35 operates to operate a predetermined shift fork (the shift fork selected by the select actuator) to engage a predetermined gear (step
S3), the operation ends. However, if the switch 34b fails, according to the present invention, the error determining means makes the following determination in step 1 described above.

In FIG. 2b, if the shift actuator 35 is operated to set the shift shaft 2 to the neutral position (step S11),
The control device 50 determines whether the neutral switch 34b has issued a signal (step S12).
If YES in step S12, there is no malfunction, so the operation is completed, and if necessary, the operation in step S2 in FIG. 2a is performed. If the shift actuator 35 has been operated to the neutral position but no signal is output from the neutral switch 34b (NO in step S12), the error determining means 51 determines whether a specified time, for example 0.5 seconds, has elapsed. (Step S13), and after a predetermined time has elapsed, the control device 50 determines whether or not the predetermined select actuator 4 is actuated (Step S13).
S14). This determination determines whether the control device 50 is operating the select actuator 4 or not. If NO, it is determined whether the select position switch 9a is outputting a signal (step S16). If all the switches 9a are outputting signals, it is known that they are in the neutral position, so the error determining means 51 sends a signal to the error lamp 52, turns on the error lamp (step S18), and ends the operation. This lets the driver know that there is a malfunction. Then move on to step S2,
The gear shifting operation continues.

On the other hand, if YES in step S14, that is, if the predetermined select actuator 4 is operating, the select actuator is temporarily turned off (step S15), and it is determined whether the select switch 9a is outputting a signal. In other words, it is determined that the select operation is not performed (step S16). If the select operation is not performed,
As mentioned above, there is no problem, but NO in step S16 indicates that the shift fork is fitted to the shift shaft. After a predetermined period of time, for example 0.3 seconds (step S17), if the switch 9a is still not outputting a signal (in the case of YES), this is determined to be a failure and the process moves to the error processing routine.

[Effects of the invention] As described above, according to the present invention, the following excellent effects are achieved.

(1) The shift shaft always passes through the neutral position during a shift change, so if the neutral switch does not issue a signal during a shift change, it is determined that the neutral switch is malfunctioning, and the error determination means issues a signal, so the operation is stopped. It is possible to notify the operator of a malfunction of the neutral switch.

(2) When all the select actuators return to their original positions and the sensor of the select actuator is in a position where the select is not set, the gear change operation continues, so there is no problem in driving the vehicle.

(3) Since the failure of the neutral switch is confirmed by the selector switch, the control device itself can determine whether a failure of the actuator is a failure of only the switch, and the driver can drive with peace of mind.

[Brief explanation of the drawing]

Fig. 1 is an overall explanatory diagram of a vehicle in which the present invention is implemented, Fig. 2a is a flowchart showing the operation of a conventional device, Fig. 2b is a flowchart of a control device in which the present invention is implemented, and Fig. 3 The figure is a cross-sectional side view of the shift mechanism. 2...Shift shaft, 3a, 3b, 3c...
Shift fork, 4a, 4b, 4c...Select actuator, 9a, 9b...Select position switch, 34a, 34b, 34c...Shift position switch, 35...Shift actuator, 50...Control device , 51...Error determination means, 52...Error lamp.

Claims (1)

[Scope of utility model registration request] A shift position switch that detects the position of one shift shaft operated by a shift actuator is provided, and a select actuator is also provided that integrates one of the shift forks into the shift shaft. An automatic transmission system for a vehicle is equipped with a sensor that detects the operating position of the select actuator and a neutral switch that detects that the shift shaft is in the neutral position. A control device is provided with an error determination means for emitting a signal when the neutral switch does not emit a signal due to a failure of the detection sensor and the sensor of the select actuator does emit a signal. 1. An automatic transmission device for a vehicle, characterized in that even if a signal indicating that the gear is in the gear position is not established, the gear shifting operation is continued when all the sensors of the select actuators have returned to the position where the gear is not set.