WO2005080832A1

WO2005080832A1 - Gearshift transmission

Info

Publication number: WO2005080832A1
Application number: PCT/NO2005/000055
Authority: WO
Inventors: Sven BJØRKGÅRD
Original assignee: Kongsberg Automotive As
Priority date: 2004-02-24
Filing date: 2005-02-15
Publication date: 2005-09-01
Also published as: SE0400431D0; SE526837C2; SE0400431L

Abstract

Gearshift transmission for vehicles with a gearbox (11), which has components that can be moved in order to attain a gearshift when a suitable manual force is exerted against a gear stick (1). The gearshift transmission comprises a two-armed lever with a first and a second arm portion (5 and 7 respectively). The lever comprises a first end portion (6), which is arranged to be influenced by a force that is proportional to the manual force, and a second end portion (8), which is arranged for connection with the components. The second arm portion (7) is telescopic and the lever comprises a sensor device (40) for measuring the value of a parameter that is proportional to the manual force and for transmitting a signal for possible telescopic increase in the length of the second arm portion (7).

Description

Gearshift Transmission The invention relates to a gearshift transmission of the type indicated in the introduction to claim 1.

5 For manual operation of vehicle gearboxes it is known that components of the gearbox can be moved by means of a gear stick, which is in the form of a two- armed lever. The gear stick is rotatably mounted on, e.g., the vehicle's chassis at a point on the gear stick that divides the gear stick into a first arm portion with a first end portion and a first central portion, and a second arm portion with a second end iθ portion and a second central portion. The end portions are located at a distance from the mounting point and the central portions are located near the mounting point.

.During a gearshift operation, variations may occur in the manual force that has to be exerted by a driver of the vehicle against the first end portion in order to move the

15 gear stick. This may happen, e.g., when a synchronisation of shafts of the gearbox is initiated during the operation or when the gear stick is moved rapidly, thus generating motion-dependent forces such as viscosity forces or inertial forces. This is illustrated in fig. 1 by the solid-drawn curve, where a force F, which a driver of the vehicle exerts with his hand against a handle of a gear stick, is illustrated as a 0 function of the handle's travel distance S, and where the force increases with increasing travel distance to a maximum value and subsequently decreases.

In order to avoid this drawback, the length of the first arm portion may be variable, with the first end portion being capable of being moved telescopically, i.e. axially

25 relative to the first central portion. With such a gear stick a driver of the vehicle can temporarily pull the first end portion axially relative to the first central portion and away from the mounting point, with the result that the length of the first arm portion is increased if there is a need for an increased operational force. When there is no , longer any need for a first arm portion of great length, this length can be reduced by

30 pushing the first end portion back axially towards the mounting point. With this embodiment of the gear stick, during the telescopic movement the driver has to move his hand between two positions, where in at least one of the positions the hand does not have an optimal, ergonomic position. Furthermore, the result of this arrangement is that the hand movement and thereby the performance of the gearshift

35 operation takes a long time.

In order to reduce the manual force necessary for movement of the component, for gear arrangements with a gear stick designed with arm portions of fixed length, it is known for the gear stick to cooperate with a servo or auxiliary device, which is 0 connected to the component of the gearbox, and which is arranged to influence the component of the gearbox with a greater force than the force exerted by the second arm portion against the servo device. This permits the length of the hand movement to be small without simultaneously requiring the manual force necessary for performing a gear change to be great. However, this embodiment of the gearshift device is expensive.

As regards a gear stick with a movable handle, reference should be made to the applicant's patent SE 464662, which, however, is illustrated in connection with another device. The object of the invention is to provide a gearshift device of the type mentioned in the introduction, which is not encumbered by the above-mentioned disadvantages.

The characteristic of the invention will be seen in the characterising features indicated in the claims.

The invention will now be described in greater detail with reference to the drawing, which schematically illustrates examples of embodiments of a gearshift device - according to the invention. Fig. 2 is a side view of a vertically extending, rod-shaped gear stick and components of a vehicle, which are connected to the gear stick, for a first embodiment of the gearshift device according to the invention.

Fig. 3 illustrates a vertical section through the area of the gear stick indicated by III in fig. 2.

Fig. 4 illustrates a vertical section corresponding to that illustrated in fig. 3, but for a second embodiment of the gearshift device. As can be seen in fig. 2, the gearshift device comprises a gear stick 1, which is substantially in the form of a two-armed lever, which is rotatably mounted on a pivot 2, thus enabling the gear stick to be rotated clockwise or anticlockwise in the paper plane as indicated by a double arrow A. The pivot 2 is attached, e.g. to a chassis 3 of a vehicle and the paper plane may be a vertical plane of the vehicle.

The gear stick 1 has a first arm portion 5 with a first end portion 6 located at a distance from the pivot 2 and provided in the form of a handle. A driver of the vehicle can grip this handle with one hand and move it in order to perform a gear change.

On the opposite side of the pivot 2 the gear stick 1 has a second arm portion 7 with a second end portion 8, which is similarly located at a distance from the pivot 2, and which is connected to a transmission element 9 such as a cable or a rod via an articulated axle 18.

The first arm portion 5 has a longitudinal axis 4' and the second arm portion 7 has a longitudinal axis 4", these longitudinal axes intersecting the pivot's longitudinal axis. In fig. 2 the two longitudinal axes 4' and 4" are coincident, thus forming a common longitudinal axis 4 for the gear stick, but they may extend at an angle relative to each other, whereby the gear stick 1 forms an angular lever.

Via the cable 9 a force can be transmitted from the second end portion 8 to a component 10 of a gearbox 11. In the normal manner for vehicles, the gearbox 11 has an input shaft 12 connected to an engine 13 and an output shaft 14 connected to driving wheels 15 of the vehicle. The transmission element 9 may comprise joints or the like (not shown) which are mounted in the chassis in a known per se manner, thus permitting a movement of the transmission element 9 when the second end portion_.8 is moved along a circular arc about the pivot 2 on movement of the gear stick 1.

It can be seen in fig. 2 that the first arm portion 5 also has a first central portion 16 and that the second arm portion 7 has a second central portion 17, these central portions 16, 17 being located near the pivot 2 and together forming a central area of the gear stick 1 through which the pivot 2 extends.

As illustrated in fig. 3, the second central portion 17 and the second end portion 8 are provided as two separate components that can be moved telescopically relative to each other.

The second central portion 17 may therefore comprise an elongated sleeve portion 24 with a bore 25, whose longitudinal axis in the embodiment illustrated coincides with the longitudinal axis 4 of the gear stick 1. The bore 25 has an inner wall 26. Near the pivot 2, i.e. at the internal end of the bore, the bore 25 is terminated by a bottom 27, and at the opposite or external end of the bore, the bore 25 has an opening 28.

In the bore 25 and near its opening 28 is mounted a tubular solenoid 30, whose radially external surface is attached, e.g. glued, to the inner wall 26. Near the end of the solenoid 30 facing the pivot 2, in the bore 25 is inserted an element 32 that abuts against the inner wall 26 and is slightly elastically yielding in the transverse direction of the second arm portion 7, i.e. across the longitudinal axis 4. The element 32 may be a rubber-elastic ring. Through the element 32 there may extend a tubular sleeve 33, e.g. of metal, whose radially external surface abuts against and may be attached to the radially internal surface of the element 32, where the sleeve 33 may be press-fitted in or glued to the element 32. The sleeve has an axially through-going passage.

The second end portion 8 of the second arm portion 7 is in the form of a rod that extends slidably through the through-going passage of the tubular sleeve 33.

Considered from the articulated axle 18 in the direction of the longitudinal axis 4 towards the pivot 2, the second end portion 8 extends first through the solenoid 30 with a relatively large clearance, and thereafter slidably through the sleeve 33. An end area 34 of the second end portion 8, which protrudes from the sleeve 33 and faces the pivot 2, is terminated by a transverse end surface or support surface 36 located between the bottom 27 and the elastic element 32. In the known manner a part of the second end portion 8, which is arranged to project into the solenoid 30, is made of a ferromagnetic material, forming a core for the solenoid 30. The lateral surface of the end area 34 forms an abutment surface 35.

Between the support surface 36 and the bottom 27 there is provided an elastic body 37, such as a- compression spring, which constantly attempts to push the second end portion 8 axially away from the bottom 27.

Furthermore, at least one sensor 40 is mounted in the bore 25. The sensor 40 has a stator 41, which is attached to the second central portion 17, and a movable part or sensing body 42-, which is arranged to abut constantly against the abutment surface 35. The sensor may be of the type comprising a potentiometer, which is connected to the sensing body 42.

On account of the elasticity of the elastic element 32, the second end portion 8 may be angularly displaced about the articulated axle 18 in the paper plane for figs. 2 and 3 a small angle relative to the second central portion 17. The clearance between the second end portion 8 and the solenoid 30 hereby permits such an angular displacement.

During such an angular displacement of the second end portion 8 relative to the second central portion 17, the sensor 40 can record this movement or displacement and via a wire 44 transmit a corresponding signal either directly to the solenoid 30 - or to a control device 45, e.g. a computer, which in turn is arranged to transmit an electrical signal to the solenoid 30 via a wire 46, thus causing a force to be exerted thereby that attempts to pull the second end portion 8 into the second central portion 17.

If a force is exerted against the gear stick's first end portion or the handle 6 in order to provide a gear change, and attempts are thereby made to rotate the gear stick in a first direction about the pivot 2, a corresponding force will be exerted by the second central portion 17 against the second end portion 8 via the elastic element 32. The elastic element 32 thereby becomes compressed in the transverse direction, and an angular displacement is also obtained between the second end portion or the rod 8 and the sleeve portion 24. The sensor's sensing body 42 will record this compression and angular displacement in this first direction and transmit a corresponding sensor signal to the computer 45.

The computer can undertake a continuous evaluation of the sensor signals and transmit a control signal to the solenoid 30 when they exceed a certain threshold value corresponding to a fixed, maximum manual force against the gear stick's handle, with the result that the solenoid 30 generates a magnetic field that causes the second end portion 8 to be pulled further into the solenoid and the bore 25 of the sleeve portion 24 while overcoming the force exerted by the spring 37, thus causing a reduction in the length of the second arm portion 7. A force can thereby be exerted by this second arm portion 7 against the cable 9, which force is increased relative to the force that was exerted before the core was pulled into the bore 25 while maintaining the same force against the handle.

Instead of the computer being arranged to transmit a control signal directly to the solenoid, the computer may be arranged to transmit a control signal to a device such as an electrical relay (not shown), which in turn guides an electric current or main current to the solenoid for pulling in the second end portion 8.

If the force exerted against the gear stick's handle is subsequently reduced to such an extent that the sensor signal is less than the threshold value, the control signal from the computer 45 for retracting the second end portion 8 into the second central portion 17 may cease. The spring 37 can thereby push the second end portion 8 in the opposite direction relative to the second central portion 17, thus obtaining the original relative position of these portions and the length of the second arm portion 7 is increased to the original value.

Instead of the computer transmitting control signals to the solenoid in this fashion, the sensor device may be arranged for this purpose.

According to a second embodiment of the device according to the invention, the sensor 40 may be arranged to transmit a sensor signal that is proportional to the angular displacement of the second end portion 8 relative to the sleeve portion 24, and the control device 45 may be arranged to transmit a corresponding, proportional control signal to the solenoid 30 for retracting the second end portion 8 into the solenoid 30. Thus the reduction in the length of the second arm portion 7 can be proportional to the instantaneous force exerted against the gear stick's handle. The solenoid and the core form an electric motor device for relative continuous or- stepwise movement of these two components.

Instead of a motor device of this type, any other suitable motor device may be employed that generates a relative, controllable movement of the telescopic components. The motor device may therefore comprise a motor such as an electric step motor, which permits a continuous or stepwise movement of the second end portion 8 relative to the second central portion 17. Furthermore, the motor device may comprise, e.g., a pneumatic or hydraulic motor and a magnetic valve device for controlling a compressed fluid flow for operation of this motor.

The motor device may possibly cause a relative movement of the telescopic components in both directions depending on the sensor signal, thus removing the need for a return spring. ^•

By this means the object can be achieved that the manual force necessary for movement of the gear stick can be reduced during a gear change, e.g., as indicated by the dotted curve in fig. 1.

Even though it has been stated above that the gear stick is in the form of a two- armed lever that can be rotated about a pivot and has arm portions located on opposite sides of a pivot, it will be understood that the gear stick may be in the form of a one-armed lever, where the arm portions are located on the same side of the pivot. In the latter case too, a stick portion may have a. variable length, thus permitting the force exerted by the gear stick against components of the gearbox to be increased without the necessity of a corresponding increase in the force exerted against the gear stick's handle.

Even though it has been stated above that the gear stick is arranged to be rotated only in the paper plane and the pivot extends perpendicularly thereto, it will be understood that the gear stick may be mounted in another way, thus enabling it also to be rotated about an axis extending in the paper plane. Additional sensors may hereby be provided which record such additional rotation and which may be capable of effecting a reduction in the length of the second arm portion in this case too.

With the device according to the invention the driver does not need to^" move his hand away from the pivot 2 in relation to the gear stick's handle in order thereby to reduce the manual force necessary for performing a gear change, since the length of the gear stick is varied automatically when the manual force for implementing a gear change exceeds a fixed value. Thus with a two-armed gear stick the gear stick's handle can be constantly located in an ergonomically correct position relative to the driver, in addition to which the gearshift operation is facilitated. Fig. 4 illustrates a second embodiment of the invention, and in fig. 4 and fig. 3 the same reference numerals are employed for corresponding components.

5 In the case of the second embodiment of the invention too, the second end portion 8 extends telescopically into the sleeve portion 24 of the second central portion 17.

The second end portion 8, however, is axially slidably mounted in a slide bearing 50, which may comprise the solenoid. At axial distance from the slide bearing 50

10 the second end portion 8 is also axially slidably mounted in a sensor device 51, which, like the slide bearing 50, is arranged to support the second end portion 8 radially in such a manner that the second end portion is only arranged to be very slightly angularly displaced or moved relative to the sleeve portion 24. This sensor device 51 comprises a device (not shown) that is suitable for recording a force

15 exerted in the transverse direction of the second arm portion 7, where this device may comprise, e.g. a strain gauge, which measures mechanical stresses in the sensor device as a result of the influence of the force.

The sensor device 51 may be connected to a computer 45 and the computer 45 may 20 be connected to the solenoid 30. The, solenoid 30 is arranged to pull the second end portion 8 towards the pivot 2 when, as a result of the exertion of a force against the handle of the stick, a signal is transmitted from the sensor device 51 to the computer 45, and a signal is transmitted from the computer 45 to the solenoid 30, as described above in connection with the first embodiment of the invention. When these signals 25 cease,, a return spring 37 causes a movement of the second end portion 8 in the opposite direction towards the original position.

Even though a gearshift device has been described above where the sensor device 51 ,which records a force that seeks to generate a gear change, is located in the

30. second arm portion 7, it will be appreciated that a corresponding sensor device may be comprised of the first arm portion 5. Thus the handle, for example, may be movable relative to other portions of the first end portion 6, and the sensor device may be mounted between the handle and these other portions. The second end portion 8 and the second central portion 7 may therefore only be comprised of a

35 solenoid, which in addition constitutes a slide bearing for axial guidance of the second end portion 8.

According to the invention the gear stick's first end portion may carry a handle, which is movable relative to the first end portion, and between these components a 40 sensor may be mounted. When the driver of the vehicle exerts a force against the handle, the sensor can thereby measure a relative movement of the handle and this end portion and transmit corresponding sensor signals via a computer to the motor device or directly to the motor device. In this connection it will be understood that a lever according to the invention need not be composed of the gear stick, but it may be located at any point in the transmission between the gear stick and the gearbox. The sensor signals from the sensor at the handle may therefore be transmitted to the lever, which may be located at a distance from the gear stick.

If a return spring is provided similar to the return spring 37, it will be appreciated that it may attempt to reduce the length of the second arm portion instead of increasing this length, and that the solenoid will hereby be constantly supplied with current in order to counteract the spring force, this current being broken when, e.g., the threshold value is exceeded..

Even though it has been stated above that the second central portion comprises a sleeve portion wherein a solenoid is mounted, and that the second end portion is arranged to be pulled into the solenoid when an electrical signal is supplied thereto, it will be understood that the second end portion may instead comprise a sleeve ^• portion wherein a solenoid is mounted, and that the second central portion may comprise a rod that is arranged to be pulled into the solenoid.

In order to avoid any risk of the telescopic components of the device becoming jammed during a relative angular movement thereof, the slide bearings may have cambered surfaces or ball bearings may be employed.

Claims

1. Gearshift transmission for vehicles with a gearbox (11) that connects an engine (13) of the vehicle (3) to wheels (15) of the vehicle (3), where the gearbox has components that can be moved in order to attain a gear change when a suitable manual force is exerted against a gear stick (1) of the vehicle, and the gearshift transmission comprises a two-armed lever with •

- a first and a second arm portion (5 and 7 respectively), comprising

- a first and a second central portion (16 and 17 respectively), together forming a central area via which the gear stick (1) is rotatably mounted in the vehicle (3), and a first and second end portion (6 and 8 respectively),

- where the first end portion (6) is arranged to be influenced by a force that is proportional to the manual force, and the second end portion (8) is arranged for connection with the components of the gearbox (11), characterised in that

- the second end portion (8) and the second central portion (17) are arranged telescopically in relation to each other, and

- the lever comprises a sensor device (40) for measuring the value of a parameter that is proportional to the manual force and for transmitting an electrical sensor signal corresponding to this force to an motor device for relative telescopic movement of the second end portion (8) and the second central portion (17).

2. Gearshift transmission according to claim 1, characterised in that the lever is composed of the gear stick (1). '

3. ^" Gearshift transmission according to claim 1 , characterised in that the motor device comprises a solenoid (30) of one of the second end portion (8) and the second central portion (17), and a core of the other of the second end portion (8) and the second central portion (17).

4. Gearshift transmission according to claim 1 or 2, characterised in that the motor device is an electric motor, such as a step motor, or a compressed fluid motor controlled by a magnetic valve that is arranged to receive the sensor signal.

5. Gearshift transmission according to one of the preceding claims, characterised in that the electrical control signal to the motor device is transmitted continuously for continuous or stepwise relative movement of the second end portion (8) and the second central portion (17).

6. Gearshift transmission according to one of the claims 1-4, characterised in that the electrical signal is transmitted to the motor when a threshold value for the sensor signal is exceeded.

7. Gearshift transmission according to one of the preceding claims, characterised in that the sensor is arranged for measuring a relative movement such as an angular displacement of the telescopic components about an axis extending perpendicularly to the direction of the telescopic movement.

8. Gearshift transmission according to one of the preceding claims, characterised in that the gear stick's first end portion carries a handle, which is movable relative to the first end portion, and against which the driver can exert the manual force, and that the sensor is arranged for measuring a relative movement of the handle and this end portion.