CLIAMS:We claim,
1. An assembly (100) for determining position of a gear shift lever (101) in a vehicle, said assembly (100) comprising,
a magnet (102) fitted near the base of said gear shift lever (101) and adapted to move along with said gear shift lever (101);
a non contact magnetic sensor (103) positioned in proximity of said magnet (102) near the base of said gear shift lever (101), said non contact magnetic sensor (103) fixed in its position; and
a control unit (104) receiving the output of said non contact magnetic sensor (103) and determine the gear shift lever (101) position.
2. An assembly (100) as claimed in claim (1) wherein said non contact magnetic sensor (103) is three dimensional Hall Effect sensor.
3. An assembly (100) as claimed in claim (1) wherein said non contact magnetic sensor (103) is an eddy current based sensor.
4. An assembly (100) as claimed in claim (1) wherein said gear shift lever (101) is pivoted at the base and the relative displacement between said magnet (102) on said gear shift lever (101) and said non contact magnetic sensor (103)is indicative of a lane position selected for said gear shift lever (101).
5. An assembly (100) as claimed in claim (1) wherein said gear shift lever (101) is rotatable about a ball joint and the relative rotation between said magnet (102) on said gear shift lever (101) and said non contact magnetic sensor (103)is indicative of a gear position of said gear shift lever (101) in said selected lane.
6. An assembly (100) as claimed in claim (1) wherein said magnet (102) is a permanent magnet.
7. An electronic control unit (104) (ECU) for controlling an electronically operated clutch; said ECU adapted to receive an input from a non contact magnetic sensor (103) placed in proximity of a magnet (102) fitted on base of said gear shift lever (101), said ECU adapted to process the signal from said non contact magnetic sensor (103) and determine the position of the gear shift lever (101). ,TagSPECI:Field of the invention:
[0001] The invention relates to transmission systems. Particularly the invention relates to the gear position sensing assembly.
Background of the invention:
[0002] Lanes are defined for identification of the position of the gears in vehicles. A neutral lane is a lane where the gear shift lever moves to and fro freely when in neutral gear. The other gear lanes are typically perpendicular to the neutral lane. In a typical 6 (5+reverse) gear configuration vehicles, the gear lanes are defined as the first gear and second gear lane (Lane 1), third gear and fourth gear lane (Lane 2) and the fifth gear and reverse gear lane (Lane 3). In each of these lanes the two gears of the pair are on opposite of the neutral lane.
[0003] For vehicles with electronically actuated clutch, the gear shift intention should be detected accurately and reliably so that the clutch is disengaged at the correct instant. To detect the gear shift lever position and the change in position different types of sensor assemblies are presently known.
[0004] JP2014052794 discloses a device for detection of gear shift lever position in a manual transmission system. The device has two sensors to detect the magnetic flux and the gear shift lever position is determined from the ratio of the two sensor outputs.
Brief description of the invention:
[0005] An assembly for determining position of a gear shift lever in a vehicle is disclosed. The assembly comprises a magnet fitted near the base of said gear shift lever; a non contact magnetic sensor positioned in proximity of said magnet near the base of said gear shift lever; and a control unit receiving the output of said three dimensional non contact magnetic sensor as an input to one of its interfaces and determine the gear shift lever position.
[0006] The assembly for determining the gear position in accordance with this method requires only one sensor for detecting the position of the gear shift lever. A single non contact magnetic sensor is able to detect the gear lane selected and also if the gear shift lever is in an even gear position or an odd gear position. The device is simple in construction and can accurately detect the position of the gear shift lever.
Brief description of the accompanying drawings:
[0007] The present invention is described with reference to the following accompanying drawings:
[0008] Fig. 1illustrates an assembly for determining the position of the gear shift lever from a first view in accordance with one embodiment of this invention; and
[0009] Fig. 2 illustrates an assembly for determining the position of the gear shift lever from a second view in accordance with one embodiment of this invention.
Detailed description of the invention:
[00010] An assembly (100) for determining position of a gear shift lever (101) in a vehicle comprises a magnet (102) fitted near the base of said gear shift lever (101) and adapted to move along with the gear shift lever; a non contact magnetic sensor (103) fixed in a position in proximity of the magnet (102)near the base of said gear shift lever (101); and a control unit (104) receiving the output of the non contact magnetic sensor (103) and determine the gear shift lever (101) position.
[00011] In one embodiment of the invention the magnetic sensor (103) is three dimensional Hall Effect sensor (103). It is envisaged that the gear shift lever (101) is pivoted at the base and the relative displacement between the magnet (102) on the gear shift lever (101) and the Hall Effect sensor (103) is indicative of a lane position selected for the gear shift lever (101). Further the gear shift lever (101) is rotatable about a ball joint and the relative rotation between said magnet (102) on said gear shift lever (101) and said Hall Effect sensor (103) is indicative of a gear position of the gear shift lever (101) in the selected lane.
[00012] In another embodiment the non contact magnetic sensor (103) could be an eddy current based sensor (103).
[00013] Fig. 1 illustrates an assembly (100) for determining the position of the gear shift lever from a first view in accordance with one embodiment of this invention. The movement of the gear shift lever (101) when the gear lane is selected is illustrated and the different positions of the gear shift lever (101) and the magnet (102) with respect to the Hall Effect sensor (103) is indicated by the gear shift levers (101) shown in dotted line. As shown in Fig. 1 the magnet (102) on the gear shift lever (101) is tilting with respect to the Hall Effect sensor (103).
[00014] Fig. 2 illustrates an assembly (100) for determining the position of the gear shift lever from a second view in accordance with one embodiment of this invention. The movement of the gear shift lever (101) when the gear is selected in a particular lane is illustrated and the different positions of the gear shift lever (101) and the magnet (102) with respect to the Hall Effect sensor (103) is indicated by the gear shift levers (101) shown in dotted line. As shown in Fig. 2 the magnet (102) on the gear shift lever (101) is rotating about its axis with respect to the Hall Effect sensor (103).
[00015] In one embodiment it is envisaged that an electronic control unit (104) (ECU) is provided in a vehicle for controlling an electronically operated clutch. The ECU is adapted to receive an input from a three dimensional Hall Effect sensor (103) placed in proximity of a magnet (102) fitted on base of the gear shift lever in the vehicle. The ECU processes the signal from the Hall Effect sensor (103) and determines the position of the gear shift lever.
[00016] In vehicle with a manual clutch, the driver presses the clutch at the instant when he wants to shift the gear position. However, in vehicles with electronically operated clutch a controller will operate an actuator when the intention to shift the gears is detected. It is very critical that the clutch is opened at the correct instant when the gear shift is taking place, since if the clutch is not disengaged when the gear shift is taking place then the driver will experience a resistance and this may also result in damage to the entire transmission system.
[00017] In accordance with one embodiment of the invention, an assembly (100) for detecting the position of a gear shift lever in a vehicle is disclosed. The assembly (100) comprises a permanent magnet (102) fitted near the base on the gear shift lever. A three dimensional Hall Effect sensor (103) is mounted in proximity of the magnet (102) at the base of the gear shift lever. The output of the Hall Effect sensor (103) is provided to an electronic control unit (104). The gear shift lever (101) is pivoted at the base by a ball joint such that, it can experience motion in two ways with respect to the fixed 3dimensional Hall Effect sensor (103). When the driver wants to change the gear and moves the gear shift lever (101), the relative motion between the permanent magnet (102) on the gear shift lever (101) and the 3 dimensional Hall Effect sensor (103) indicates the gear position selected by the driver. When the gear shift lever is moved in the neutral lane for the selection of one of the gear lanes, the permanent magnet (102) experiences a tilting motion and displacement with respect to the Hall Effect sensor (103). Based on the polarity of the permanent magnet, the Hall Effect sensor (103) can detect the direction in which the gear shift lever tilts. Based on the direction of the tilt the lane that is selected by the driver is determined. For example if the top end of the gear shift lever is tilted towards the right side of the Hall Effect sensor (103) by the driver to select the right gear lane, the lower end of the gear shift lever (101) and thus the permanent magnet (102) moves towards the left side of the Hall Effect sensor (103). The polarity of the permanent magnet (102)which is closer to the Hall Effect sensor (103) is detected by the sensor (103) and the sensor (103) output is provided to the electronic control unit (104) as an input. Similarly, when the top end of the gear shift lever is tilted towards the left side of the Hall Effect sensor (103) by the driver to select the left gear lane, the lower end of the gear shift lever and thus the permanent magnet (102) moves towards the right side of the Hall Effect sensor (103). The polarity of the permanent magnet (102)which is closer to the Hall Effect sensor (103) is detected by the sensor (103) and the sensor (103) output is provided to the electronic control unit (104) as an input. When the gear shift lever is in a vertical position without being tilted in either right or left side of the Hall Effect sensor (103), to select the gear lane, then both the poles of the permanent magnet (102) are at equal distance from the Hall Effect sensor (103). The electronic control unit (104) determines the lane selected by the driver based on the output of the Hall Effect sensor (103).
[00018] In accordance with one embodiment of the invention, once the driver has selected the gear lane, to select the gear, the driver is required to move the gear shift lever in a forward or a backward direction. For example the even gears (2nd, 4th gears) are in a position when the gear shift lever is moved backwards and the odd gears (1st, 3rd, 5th gears) are in a position when the gear shift lever is moved forward as compared to the Hall Effect sensor (103). When the gear shift lever (101) is moved in a forward direction with respect to the sensor (103), the permanent magnet (102) rotates in a clockwise direction about its own axis but remains at the same distance from the Hall Effect sensor (103). Similarly, when the gear shift lever (101) is moved in a backward direction with respect to the sensor (103), the permanent magnet (102) rotates in an anti-clockwise direction about its own axis but remains at the same distance from the Hall Effect sensor (103). Based on the direction of rotation of the permanent magnet (102) with respect to the Hall Effect sensor (103), the position of the gear shift lever (101) is determined by the electronic control unit (104).
[00019] It should be understood that embodiments explained in the description above are only illustrative and do not limit the scope of this invention. Many such embodiments and other modifications and changes in the embodiment explained in the description are envisaged. The movement of the gear shift lever in left, right and forward and backwards as mentioned above is only for the purpose of the explanation and any motion in a different direction than above may be possible to detect the position of the gear shift lever. In one embodiment any magnetic sensor (103) other than a Hall Effect sensor (103) like an an eddy current based sensor, may be placed in proximity of the gear shift lever base to determine the change in position of the permanent magnet (102)mounted at the base of the gear shift lever. The scope of the invention is only limited by the scope of the claims.