JPH0714896Y2 - Vehicle speed detection device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a vehicle speed detection device.

<Prior Art> Conventionally, an electromagnetic pickup type rotation speed sensor is provided on an output shaft of a transmission, and a vehicle speed is detected based on an output voltage of the rotation speed sensor.

<Problems to be solved by the invention> By the way, when the output voltage of the rotation speed sensor is greatly reduced, the vehicle speed cannot be detected from the rotation speed of the output shaft, but the lower limit rotation speed is about 150 rpm and the lower limit rotation speed is The speed is about 5km / h when converted to vehicle speed. For this reason,
The current rotation speed sensor cannot detect a vehicle speed of less than 5 km / h, and there is a problem that the vehicle speed condition for shifting to idle rotation speed control has to be set to, for example, 8 km / h.

The present invention has been made in view of such circumstances, and an object thereof is to provide a vehicle speed detection device capable of detecting a vehicle speed even at an extremely low vehicle speed.

<Means for Solving the Problem> Therefore, in the present invention, as shown in FIG. 1, in the vehicle in which the output of the engine A is transmitted to the drive wheels via the transmission B, the output shaft of the transmission B is An output shaft rotational speed detecting means C for detecting the rotational speed, an input shaft rotational speed detecting means D for detecting the rotational speed of the input shaft of the transmission B, the input shaft rotational speed detecting means D or the output shaft rotational speed detecting means. Vehicle speed determination means E for determining whether or not the vehicle speed based on the rotation speed detected by the means C is less than or equal to a predetermined value, gear shift operation determination means F for determining whether the gear shift operation of the transmission B is in progress, and the vehicle speed And a vehicle speed setting means G for setting the vehicle speed based on the detected rotation speed of the input shaft rotation speed detection means D and the gear ratio of the transmission, I was prepared.

<Operation> As described above, when the vehicle speed is equal to or lower than the predetermined value and the non-shift operation is performed, the rotation speed of the input shaft of the transmission and the shift speed of the transmission that are usually higher than the rotation speed of the output shaft of the transmission are changed. The vehicle speed can be detected even in the low vehicle speed range by setting the vehicle speed based on the ratio.

<Embodiment> An embodiment of the present invention will be described below with reference to FIGS. 2 and 3.

In FIG. 2, the output of the engine 1 is transmitted to the automatic transmission 3 via the torque converter 2 and then to the drive wheels via the output shaft 4 of the automatic transmission 3.

The automatic transmission 3 is provided with a front clutch, a rear clutch, a brake band, a low & reverse brake, a one-way clutch, etc., and solenoid valves 3A to 3E for supplying hydraulic oil to them. Then, the shift control device 5
For example, based on the vehicle speed and the throttle opening, the solenoid valves 3A to 3E are operated to perform the gear shift operation.

A disk-shaped first signal disk plate 6 is coaxially attached to the output shaft 4 of the automatic transmission 3, and projections are formed on the outer peripheral wall of the first signal disk plate 6 at substantially constant intervals. The first signal disc plate 6
The first sensor body 7 is provided so as to oppose the outer peripheral wall of the first sensor body 7, and the first sensor body 7 is magnetically configured to have a coil wound around an iron core. Then, the projection of the first signal disk plate 6 cuts the magnetic field of the iron core, so that the output shaft 4
The voltage corresponding to the rotation speed of is output from the coil of the first sensor body 7 to the engine control device 8. Therefore, the first
The signal disk plate 6 and the first sensor body 7 constitute an output shaft rotation speed detecting means. The engine control device 8 performs fuel injection control and ignition control.

A second signal disk plate 9 is coaxially attached to the output shaft of the torque converter 2, and projections are formed at predetermined intervals on the outer peripheral wall of the second signal disk plate 9. A second sensor body 10 is provided so as to face the outer peripheral wall of the second signal disk plate 9, and the second sensor body 10 is configured by winding a coil around a magnetic iron core. Then, like the first sensor body 7, the second sensor body 7
The coil of the sensor body 10 outputs a voltage corresponding to the turbine rotation speed of the torque converter 2 to the engine control device 8. Therefore, the second signal disk plate 9 and the second sensor body 10 constitute the input shaft rotation speed detecting means.

Data is exchanged between the engine control device 8 and the shift control device 5 by mutual communication, and the engine control device 8 executes the routine shown in the flowchart of FIG.

Here, the engine control device 8 constitutes a vehicle speed determination means, a shift operation determination means, and a vehicle speed setting means.

Next, the operation will be described with reference to the flowchart of FIG.

In S1, it is determined whether or not a flag, which will be described later, is 1, and if YES, the process proceeds to S2, and if NO, the process proceeds to S6.

In S2, the vehicle speed VSP is calculated based on the output voltage from the first sensor body 7, that is, the rotation speed of the output shaft 4. Specifically, since the output voltage (rotational speed) is proportional to the vehicle speed VSP, the vehicle speed VSP can be calculated by multiplying the output voltage by a constant.
Ask for.

In S3, the vehicle speed VSP obtained in S2 is the first value as the predetermined value.
It is determined whether or not the vehicle speed is equal to or higher than the set vehicle speed V1 (for example, 10 km / h). If YES, the process proceeds to S4, and if NO, the process proceeds to S6.

In S4, the flag is set to 1 in order to determine the vehicle speed based on the output voltage from the first sensor body 7 in the next routine.

In S5, the vehicle speed VSP obtained in S2 is set as the vehicle speed.

In S6, it is determined based on the input data from the shift control device 5 whether or not the shift operation is currently being performed. If YES, the routine is ended, and if NO, that is, in the non-shift operation, S7.
Proceed to.

In S7, the vehicle speed VSP is calculated based on the output voltage from the second sensor body 10, that is, the turbine rotation speed and the current gear ratio of the transmission 3. Specifically, the vehicle speed VSP is obtained by multiplying the output voltage by a constant and distinguishing it by the gear ratio.

In S8, it is determined whether or not the vehicle speed VSP obtained in S7 is equal to or higher than the second set vehicle speed V2 (for example, 8 km / h).
If NO, proceed to S9. This is a step for enabling the vehicle speed to be detected from the rotation speed of the output shaft 4 when the actual vehicle speed increases to 10 km / h or more next time.

In S9, the flag is set to zero in the next routine so as to determine the vehicle speed based on the input voltage from the second sensor body 10.

Then, in S5, the vehicle speed VSP based on the turbine rotation speed obtained in S7 is determined as the vehicle speed. Here, when the current vehicle speed VSP is less than 10 km / h and 8 km / h or more, the flag is set to 1 in S4, but in this routine, the vehicle speed is fixed based on the turbine rotation speed.

When it is determined in S6 that the gear shift operation is in progress, the routine is ended without calculating the vehicle speed, but since the gear shift operation time is about 0.7 seconds at the maximum, no problem occurs even if the vehicle speed is not detected. Further, the vehicle speed may be detected from the rotation speed of the output shaft 4 of the transmission 3 during the shift operation.

As described above, when the vehicle speed VSP is less than the first set vehicle speed V1, the vehicle speed is obtained based on the turbine rotation speed and the gear ratio input to the transmission 3, so the transmission 3
The vehicle speed can be obtained from the turbine rotation speed higher than the rotation speed of the output shaft 4, and thus the vehicle speed can be detected to a lower vehicle speed range than the conventional one. Specifically, when the rotation speed of the output shaft 4 is 150 rpm at the first speed, the turbine rotation speed is about 4
It becomes 20r.pm, and when the turbine speed is the lower limit speed of 150r.pm that can detect the vehicle speed, the vehicle speed is about 1.8km / h, and if the vehicle speed is detected by the turbine speed, it is about 1.8k.
The vehicle speed can be detected up to m / h.

<Effect of the Invention> As described above, the present invention determines the vehicle speed based on the input shaft rotation speed of the transmission and the gear ratio when the vehicle speed is in the low vehicle speed range of a predetermined value or less and the non-gear operation is performed. Because I did
The vehicle speed can be detected in a lower vehicle speed range than before.

[Brief description of drawings]

FIG. 1 is a diagram corresponding to the claims of the present invention, FIG. 2 is a configuration diagram showing an embodiment of the present invention, and FIG. 3 is a flowchart of the same. 1 ... Engine, 2 ... Torque converter, 3 ... Automatic transmission, 4 ... Output shaft, 6 ... First signal disk plate, 7 ... First sensor body, 8 ... Engine control device, 9 ... … Second signal disc plate, 10 …… Second
Sensor body

Claims (1)

[Scope of utility model registration request] 1. A vehicle for transmitting an output of an engine to drive wheels through a transmission, an output shaft rotation speed detecting means for detecting a rotation speed of an output shaft of the transmission, and a rotation of an input shaft of the transmission. Input shaft rotation speed detection means for detecting speed,
Vehicle speed determination means for determining whether the vehicle speed based on the rotation speed detected by the input shaft rotation speed detection means or the output shaft rotation speed detection means is less than or equal to a predetermined value, and whether the speed change operation of the transmission is being performed And a vehicle speed based on the detected rotation speed of the input shaft rotation speed detection means and the gear ratio of the transmission when the vehicle speed is determined to be a predetermined value or less and it is determined that the vehicle is in a non-speed change operation. A vehicle speed detecting device for a vehicle, comprising: a vehicle speed setting means for setting.