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Device and method for controlling gear shifting of subtransmission

Imported: 24 Feb '17 | Published: 09 Sep '03

Kaoru Kigoshi

USPTO - Utility Patents

Abstract

In a procedure for controlling gear shifting of a subtransmission which can be carried out only when a vehicle is substantially standing, a vehicle speed pulse is generated, a time is counted from the time each vehicle speed pulse is generated (steps

101, 102). This time is a period for which a first condition by which the vehicle can be considered, regardless of the pulse, to be running is satisfied. At the same time the first condition becomes unsatisfied from a satisfied state, the counted time is determined to be a first condition satisfied period T

1, and a waiting period Tw is determined in a predetermined manner by using the first condition satisfied period (step

103). A time T

2 is counted from the time the first condition becomes unsatisfied, and when the counted time T

2 reaches the determined waiting period, the gear shifting of the subtransmission becomes possible (step

105).

Description

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram showing a procedure of controlling gear shifting of a subtransmission according to an embodiment of the present invention;

FIG. 2 is a time chart showing control of the gear shifting of the subtransmission and a state when a vehicle stops according to the embodiment of FIG. 1;

FIG. 3 is a graph showing relation between a first condition satisfied period and a waiting period according to the embodiment of FIG. 1;

FIG. 4 is a diagram showing structure of a device for controlling the gear shifting according to the embodiment of FIG. 1;

FIG. 5 is a longitudinal sectional view showing a transfer according to the embodiment of FIG. 1, the left side of the view is a front side, and the right side is a rear side;

FIG. 6 is a schematic front view of the transfer of FIG. 5; and

FIG. 7 is a plan view of a four-wheel-drive vehicle according to the embodiment of FIG. 1, the left side of the view is a front side of the vehicle, and the right side is a rear side.

Claims

1. A device for controlling gear shifting of a subtransmission provided on a vehicle, comprising:

2. The device for controlling the gear shifting of the subtransmission according to claim 1, further comprising:

3. The device for controlling the gear shifting of the subtransmission according to claim 2, wherein when the switch is operated and switched, if the second condition is not satisfied, the gear shifting of the subtransmission is not carried out even if the second condition becomes satisfied after the switch is operated and switched.

4. The device for controlling the gear shifting of the subtransmission according to claim 1, wherein the first condition includes a requirement that an engine should be in a running state, and a requirement that a shift position of a main transmission of the vehicle should be a position other than a neutral position and a parking position.

5. The device for controlling the gear shifting of the subtransmission according to claim 2, wherein the second condition further includes a requirement that an engine revolution speed should be equal to or less than a predetermined value, and a requirement that a shift position of a main transmission of the vehicle should be a neutral position or a parking position.

6. The device for controlling the gear shifting of the subtransmission according to claim 1, wherein the predetermined manner is a manner in which the waiting period is increased as the first condition satisfied period is increased, and a increase rate of the waiting period to the first condition satisfied period is changed to a larger value from a smaller value when the first condition satisfied period exceeds a predetermined threshold value.

7. The device for controlling the gear shifting of the subtransmission according to claim 6, wherein the predetermined threshold value is approximately a maximum period for which the vehicle speed pulse is awaited.

8. The device for controlling the gear shifting of the subtransmission according to claim 1, wherein at the same time the first condition becomes unsatisfied from the satisfied state, the period counted by the first timer means is retained, and then if the first condition becomes satisfied from an unsatisfied state where the period counted by the first timer means is retained, the first timer means starts an additional count of the retained period.

9. The device for controlling the gear shifting of the subtransmission according to claim 1, wherein the period counted by the first timer means is cleared each time the each vehicle speed pulse is generated.

10. The device for controlling the gear shifting of the subtransmission according to claim 1, wherein the period counted by the first timer means is cleared when an ignition switch is turned off.

11. The device for controlling the gear shifting of the subtransmission according to claim 1, wherein at the same time the gear shifting of the subtransmission is started or completed, the period counted by the first timer means is cleared.

12. The device for controlling the gear shifting of the subtransmission according to claim 1, wherein the vehicle is a four-wheel-drive vehicle, and the subtransmission is installed on a transfer of the four-wheel-drive vehicle.

13. A method of controlling gear shifting of a subtransmission by using an actuator and a control unit, in which the subtransmission is installed on a vehicle, and can be switched only when the vehicle is substantially standing, said method comprising: