US 4,784,007 A · Method and apparatus for actuating vehicle transmission

Abstract

A vehicle transmission system has an internal lever for changing transmission gears, a select actuator for moving the internal lever to neutral positions N1, N2, N3 in a first direction, a shift actuator for moving the internal lever to 1st-5th gear positions and a reverse position in a second direction substantially normal to the first direction, and a clutch actuator for actuating a clutch. While any one of the actuators is in operation, the pressure of a fluid discharged from the operating actuator is prevented from acting on the select actuator and/or the shift actuator which is not in operation by applying a fluid pressure to the inoperative select actuator and/or the shift actuator to fix the actuator or actuators in a current position against operation, thereby allowing the transmission gears to be changed accurately and smoothly.

Claims4

Dependent claims

A method of actuating a vehicle parallel-gear transmission having a plurality of gears and an internal lever for moving shift blocks connected with shift rods and shift forks for changing gear ratios of the transmission, a hydraulically controlled select actuator operatively connected to said internal lever for moving said internal lever in a select direction, a hydraulically controlled shift actuator operatively connected to said internal lever for moving said internal lever in a shift direction substantially normal to said select direction, and a common fluid discharge passage connected to fluid discharge ports of said select and shift actuators, the select and shift actuators being alternately actuatable to effect a gear changing operation, said method comprising the steps of, in order:

(a) applying a hydraulic pressure to said select actuator in a position, to fix said select actuator in that position;
(b) applying a hydraulic pressure to said shift actuator to actuate same, so as to move the internal lever to a first neutral position;
(c) removing the hydraulic pressure from said select and shift actuators;
(d) applying a hydraulic pressure to said shift actuator in a position, to fix said shift actuator in that position;
(e) applying a hydraulic pressure to said select actuator to actuate same, so as to move the internal lever to a second neutral position;
(f) removing the hydraulic pressure from said select and shift actuators;
(g) applying a hydraulic pressure to said select actuator in a position, to fix said select actuator in that position;
(h) applying a hydraulic pressure to said shift actuator to actuate same, so as to move the internal lever and engage a desired gear ratio of the transmission;
and
(i) removing the hydraulic pressure from said select and shift actuators to free both the select and shift actuators and prevent wear of the transmission gears.

7 more elements

A method of actuating a vehicle parallel-gear transmission having a plurality of gears and an internal lever for moving shift blocks connected with shift rods and shift forks for changing gear ratios of the transmission, a hydraulically controlled select actuator operatively connected to said internal lever for moving said internal lever in a select direction, a hydraulically controlled shift actuator operatively connected to said internal lever for moving said internal lever in a shift direction substantialy normal to said select direction, a hydraulically controlled clutch actuator for connecting and disconnecting a clutch of the transmission, and a common fluid discharge passage connected to fluid discharge ports of said select and shift actuators and a fluid discharge port of said clutch actuator, the select and shift actuators being alternately actuatable to effect a gear changing operation, said method comprising the steps of, in order:

(a) applying a hydraulic pressure to said select and shift actuators, each in a position, to fix the actuators in the respective positions while the transmission is in a first gear ratio;
(b) actuating said clutch actuator, thereby disconnecting the clutch;
(c) removing the hydraulic pressure from said select and shift actuators;
(d) applying a hydraulic pressure to said select actuator in a position, to fix said select actuator in that position;
(e) applying a hydraulic pressure to said shift actuator to actuate same, so as to move the internal lever to a first neutral position;
(f) removing the hydraulic pressure from said select and shift actuators;
(g) applying a hydraulic pressure to said shift actuator in a position, to fix said shift actuator in that position;
(h) applying a hydraullic pressure to said select actuator to actuate same, so as to move the internal lever to a second neutral position;
(i) removing the hydraulic pressure from said select and shift actuators;
(j) applying a hydraulic pressure to said select actuator in a position, to fix said select actuator in that position;
(k) applying a hydraulic pressure to said shift actuator to actuate same, so as to move the internal lever and engage a desired gear ratio of the transmission;
(l) actuating the clutch actuator, thereby connecting the clutch, and, prior to or following step (1);
(m) removing the hydraulic pressure from said select and shift actuators to free both of the select and shift actuators and prevent wear of the transmission gears.

10 more elements

A method of actuating a vehicle parallel-gear transmission having a plurality of gears and an internal lever for moving shift blocks connected with shift rods and shift forks for changing gear ratios of the transmission, a hydraulically controlled select actuator operatively connected to said internal lever for moving said internal lever in a select direction, a hydraulically controlled shift actuator operatively connected to said internal lever for moving said internal lever in a shift direction substantially normal to said select direction, a hydraulically controlled clutch actuator for connecting and disconnecting a clutch of the transmission, and a common fluid discharge passage connected to fluid discharge ports of said select and shift actuators and a fluid discharge port of said clutch actuator, the select and shift actuators being alternately actuatable to effect a gear changing operation, said method comprising the steps of, in order:

(a) applying a hydraulic pressure to said select and shift actuators, each in a position, to fix the actuators in the respective positions while the transmission is in a first gear ratio;
(b) actuating said clutch actuator, thereby disconnecting the clutch;
(c) removing the hydraulic pressure from said shift actuator;
(d) applying a hydraulic pressure to said shift actuator to actuate same, so as to move the internal lever to a first neutral position;
(e) removing the hydraulic pressure from said select actuator;
(f) applying a hydraulic pressure to said select actuator to actuate same, so as to move the internal lever to a second, neutral position;
(g) removing the hydraulic pressure from said shift actuator;
(h) applying a hydraulic pressure to said shift actuator to actuate same, so as to move the internal lever and engage a desired gear ratio of the transmission;
(i) actuating the clutch actuator, thereby connecting the clutch, and, prior to or following step (1);
(j) removing the hydraulic pressure from said select and shift actuators to free both of the select and shift actuators and prevent wear of the transmission gears

7 more elements

Dependencies are inferred from the claim text.

Method and apparatus for actuating vehicle transmission

Life of this patent

Method and apparatus for actuating vehicle transmission

Life of this patent

Abstract

Claims4