DE102013218355A1 - manual transmission - Google Patents

Abstract

A gearbox has a gearbox (1), the shift finger (2) via a first piston (3) and a second piston (4) is movable, wherein the first piston (3) and the second piston (4) via proportional valves ( 8) are pressurized.

Description

The invention relates to a transmission according to the closer defined in the preamble of claim 1.

Generic manual transmissions have claws or synchronizers, by means of which gears in the transmission are operatively connected to each other in order to switch different gears can. These manual transmissions are used for example in tractor or combine harvester gears. Manual transmissions can be switched manually. To relieve the driver, manual transmissions are also switched automatically by a gear actuator is controlled accordingly.

The DE 600 10 308 T2 discloses a gearbox device, by means of which a shift finger cooperates with shift rails and switch according to the position of the shift finger, the shift rails corresponding gears. The shift finger is in operative connection with a first piston and a second piston, whereby the position of the shift finger is adjustable by means of the piston.

The DE 10 2006 009 609 A1 discloses a pressure control device of a transmission actuator, wherein the pressure medium source is arranged downstream of a proportional valve to adjust the pressure on the piston surfaces accordingly. For acting on the piston surfaces with pressure switching valves are controlled accordingly.

The present invention has for its object to provide an automatically switchable gearbox whose circuits are easily controlled.

The invention is based on the recognition that different switching forces, depending on the switchable gear, improve the switching result. Thus, the transmission on a transmission actuator, which has a shift finger, which is operatively connected to a first and a second piston, wherein each piston surface of the first and second piston is associated with a controllable via a control valve proportional valve. Thus, it is possible to set the appropriate switching power to each switching gear. For this purpose, the corresponding switching force is stored for the corresponding gear to be switched in the control unit.

In one embodiment of the invention, the gearbox has sensors which detect the position of the shift finger directly or indirectly, wherein the sensors are connected to the control unit and the control unit controls the proportional valve depending on the signal of the sensors.

In one embodiment of the invention, a displacement sensor is associated with the first piston and the second piston determines the position of the shift finger by the second sensor is designed as a position sensor.

The piston surfaces of the first and second pistons are designed so that the pressure generated by a pressure medium source in the transmission is sufficient. As a result, no additional pump is needed. By the corresponding switching force is adjustable to each switching gear, the gearbox plate can be used for several different gearbox, with only the corresponding switching force is programmed in the control unit.

Further features can be found in the description of the figures.

Show it:

1 a longitudinal section through the transmission actuator,

2 a cross section through the transmission actuator, and

3 an external view of the transmission actuator.

Fig. 1:

The gearbox 1 has a shift finger 2 on, on the one hand in a first piston 3 engages and on the other hand can be brought into operative connection with shift rails, not shown. The shift finger 2 is rotatable about the second piston 4 arranged. A displacement sensor 5 detects the position of the first piston 3 and a position sensor 6 detects the position of the shift finger 2 , By pressurizing either one or the other piston surface 7 , the first piston moves 3 ,

Fig. 2:

The shift finger 2 is rotatable about the second piston 4 arranged. The gearbox 1 has proportional valves 8th on, via which pressure medium to the piston surfaces 9 or the piston surfaces 7 of the 1 arrives. Depending on the control of the proportional valves 8th gets more or less pressure to the piston surfaces 9 respectively. 7 , which the switching force of the shift finger 2 affected. By each piston surface 7 respectively. 9 a proportional valve is assigned, the switching force of each gear can be controlled accordingly.

3:

The gearbox 1 has proportional valves 8th on which electrical connections 10 have, by means of which a not shown control unit with the proportional valves is connectable.

LIST OF REFERENCE NUMBERS

1

transmission actuator

2

shift finger

3

first piston

4

second piston

5

displacement sensor

6

position sensor

7

piston area

8th

proportional valve

9

piston area

10

electrical connections

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 60010308 T2 [0003]
• DE 102006009609 A1 [0004]

Claims (5)

Manual transmission, in which gears are switched by means of shift rails, wherein the shift rails from a gearbox ( 1 ) are moved by a shift finger ( 2 ) of the transmission actuator ( 1 ) cooperates with the shift rail, that the movement of the shift finger ( 2 ) moves the shift rail, wherein the shift finger ( 2 ) with a first piston ( 3 ) and a second piston ( 4 ) is operatively connected and the first piston ( 3 ) by pressurizing at least one piston surface ( 7 ) and the second piston ( 4 ) by pressurizing at least one piston surface ( 9 ) are movable, characterized in that each piston surface ( 7 . 9 ) a controllable via a control unit proportional valve ( 8th ), by means of which the pressure on the piston surface ( 7 . 9 ) is adjustable, whereby each gear with a previously defined force is switchable by the control unit, the proportional valve ( 8th ) accordingly controls. Manual transmission according to claim 1, characterized in that the position of the shift finger ( 2 ) via sensors ( 5 . 6 ), the sensors being connected to the control unit. Gearbox according to claim 1, characterized in that a sensor ( 5 ) is designed as a displacement sensor and with the first piston ( 3 ) and another sensor ( 6 ) with the shift finger ( 2 ) is operatively connected and as a position sensor, the position of the shift finger ( 2 ) detected. Gearbox according to claim 1, characterized in that the gearbox has a pressure medium pump which covers the pressure medium supply of the transmission and the proportional valves ( 8th ) are connected to this source of pressure medium and the piston surfaces ( 7 . 9 ) are designed so that the pressure of the pressure medium source is sufficient to generate the maximum required switching power. Method for switching a gearbox according to claim 1, characterized in that the position of the shift finger ( 2 ) by means of the sensors ( 5 . 6 ) and the proportional valve ( 8th ) according to the position of the shift finger ( 2 ) is controlled to set a previously defined switching force for the corresponding gear to be switched.

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