AU754704B2

AU754704B2 - Device for detecting the position of two axial movements

Info

Publication number: AU754704B2
Application number: AU61489/00A
Authority: AU
Inventors: Urs Caduff; Asta Reichl
Original assignee: Robert Bosch GmbH
Current assignee: Robert Bosch GmbH
Priority date: 1999-06-29
Filing date: 2000-06-16
Publication date: 2002-11-21
Anticipated expiration: 2020-06-16
Also published as: JP2003503664A; WO2001002753A1; EP1196701B1; DE50002377D1; EP1196701A1; AU6148900A; DE19929632A1

Description

I WO 01/02753 PCT/DE0001995 Device for detecting the position of two axial movements Prior Art The invention relates to a device for detecting the position of two axial movements, in particular of the shifting position of a transmission control according to the type of Claim 1. From US PS 58 45 538 a device for detecting position is known, in which a cam is secured to a shaft. On the cam is a component extending beyond the surface of the cam, which has a spiral contour on one side. Along this spiral contour slides the extension of a feeler system with the help of which the movement of the cam is detected by a sensor arranged on an extension and is converted into an electrical signal. In order to further determine the radial movement of the shaft the cam has an extension onto which a rotary element can clasp. With this device, however, it is only possible to detect a continuous movement. This means that the transmission control arranged on the shaft enables a switching only in a given sequence. For example, no moves from even to odd gears are possible.

Advantages of the invention The device of the invention for detecting the position of two axial movements with the characteristic features of Claim 1 has, over against prior art, the advantage that a separation of the even and odd gears is possible with the aid of a neutral zone. The WO 01/02753 PCT/DE0001995 2 section between the single gears can be configured identically or individually according to requirements. It is possible, therefore, to carry out a different gear shift between, for example, reverse gear and the other gears. Because the spherical metal tip of the feeler bears in the direction on the level cam surface, an axial insensitivity of the device is achieved. The transitions between the individual cam path, that is from the uneven gears to the neutral zone and then to the even gears are constructed as ramps, so that a position detection is possible without bouncing and the resulting errors in measurement. The measuring device enables the use of simple evaluation circuits, in order to make possible a clear statement concerning position, that is which gear is currently selected. This is also achieved by the neutral zone must be driven in from every gear.

By means of the measures enumerated in the subclaims, advantageous extensions and improvements of the device described in Claim 1 are possible.

Drawing Embodiments of the invention are represented in the drawing and are described in some detail in the following description. Figure 1 shows a side view of the device, Figure 2 a plan view of the device for detecting position, each without the measuring element attached, Figure 3 shows a view of the device corresponding to II/III of Figure 1, here with attached measuring element, Figure 4 a view also corresponding to III/I without the measuring element and Figure 5 a perspective representation of a modification of the embodiment.

Description of the embodiment In the Figures a device for detecting position of two axial movements is shown with the number 10, which has a shaft 11 and is part of a shift mechanism of a transmission control. The shaft 11 is connected directly or indirectly to the gear lever 12 of the transmission control. Several even gears or uneven gears and a reverse gear can be WO 01/02753 PCT/DE0001995 3 selected with the aid of the gear lever 12. A cam 15 is secured to the shaft 11, enclosing the shaft 11 in an area of approximately 1800. Both front faces 16 of the cam have a flat construction and run parallel to one another. Three cam paths 21, 22, 23 are present, one behind another, on the lateral surface of the cam 15 viewed in the axial direction. Between the cam paths 21, 22, 23 are ramps 25, 26. The cam path 22 is formed, viewed in the axial direction of the shaft 11, in the centre of the cam while the two other cam paths 21, 23 end parallel with the front faces 16 respectively.

In the embodiment the three cam paths 21, 22, 23, viewed in the axial direction, are of equal length respectively. It is also conceivable that the three cam paths 21, 22, 23 have differing lengths. Various shifting positions, which can be selected with the aid of the gear lever 12, are allocated to the cam paths 21, 22, 23. Thus the neutral position 22 is allocated to the cam path 22.

In addition, it has a lateral surface covering the entire lateral surface of the cam path with an even radius, whose central point M lies in the central point of the shaft. The even gears, that is the second and the fourth gears, are allocated, for example, to the cam path 21 and the uneven gears, that is the first, third and fifth gears and also the reverse gear are allocated to the cam path 23. If necessary the number of gears can, of course, also be greater. As can be seen clearly from Figures 3 and 4, the cam paths 21, 22, 23 each have differing radial distances from the central point of the shaft 11.

It can thus be recognised that the three cam paths 21, 22, 23 have a staggered distance from the central point M of the shaft 11, that is the cam path 21 has the least distance and the cam path 23 the greatest.

The separate shift positions are points on circular paths around the central point M of the shaft 11 allocated to the three cam paths 21, 22, 23. Thus the cam path 21 features an entry area 30 with a first radius R1. A section 31 with a constant incline S is connected to the end of this area 30. The shift position for the fourth gear is situated at the intersection point of this section 31 with a second radius R2. Now a section 32 is connected, on the end of which, that is on its intersection with a third radius R3, the shift position for the second gear is situated. The area 33 now connected has in turn the incline S and continues to an area 34, which has a fourth radius R4. This fourth area 34 is not immediately necessary for the actual shift.

WO 01/02753 PCT/DE0001995 4 The fourth radius R4 for the section 34 also corresponds to the radius for the neutral zone N, that is to the course of the side line of the second cam path 22.

The third cam path 23 now again features a first section 41 with a constant incline S.

On the end of this section 41, that is on the intersection of the section 41 with a fifth radius R5 is the shift position for the fifth gear. Now sections 42, 43, 44 and an end section 45 connect. The shift position for the third, first and for the reverse gear are on the transitions between the individual sections 41 to 45, that is on each of the intersections with the radii R5, R6, R7 and R8. The individual sections 41 to 45 again feature a constant incline S.

In the embodiment represented in the Figures the radius increases consistently from the radius R1 to the eighth radius R8. This means that the transition from one gear to another has consistent sizes. Of course, it is also possible to vary this dimension of the transition between the individual gears by increasing the radii ununiformly. It would thus be conceivable, for example, to provide a greater radial increase between the first and reverse gears in order to keep the reverse gear clearly distinct from the other gears. The above design applies fundamentally also for the constant incline S of the sections 31 to 33 or 41 to 45 indicated in this embodiment. Here also, these sections in the embodiment have the same length, that is they have the same angular dimension of Here also it is conceivable to allocate another angular dimension or differing angular dimensions to the respective sections in order to thus allocate a certain characterisation of the gear connected to a section.

As can be seen from Figure 3, a feeling lever 50 is pressed on the lateral surface of the cam 15 with the aid of a spring element 51. The feeling lever 50 has a spherical tip 52 for this purpose. The feeling lever 50 and the tip 52 can consist of metal. It is now possible with the aid of this spherical tip 52 to pick up the three-dimensional surface of the cam 15 described above both in the axial direction of the shaft 11 and in the radial direction of the shaft 11 constantly. For this process the sensor schematically represented in the Figures, which converts the movement of the feeling WO 01/02753 PCT/DE0001995 lever 50 into an electrical output signal, connects to the feeling lever 50. For this, eg.

a magnetic field sensitive sensor, a Hall element or an inductive sensor can be used.

Also during the movement of the shaft 11 Ithe spherical tip 52 of the feeling lever 50 is pressed on the lateral surface of the cam 15. An axial movement of the shaft 11 and a rotational movement of the shaft 11 takes place during the shifting process with the aid of the gear lever 12. These two movements are constantly followed by the feeling lever 50 with its end 52. If the gear lever 12 is moved from the first to the second gear, then the tip 52 of the feeling lever 50 is moved out of the shift position for the first gear, that is by the cam path 23 over the ramp 26 into neutral position, that is to the cam path 22. The tip 52 is pushed over the connecting ramp 25 to the cam path 21 and is now in the shift position for second gear. During this movement the shift in the axial and radial direction described above takes place. If the third gear is shifted to from the second, then the neutral position N, that is the cam path 22 must be passed through again. By this means all the gears one to five are separated through the neutral position N, that is through by cam path 22.

A representation of a modification of the embodiment is depicted in Figure 5 in perspective. This modification has no section 34 on the cam path 21. Moreover in Figure 5 the shift paths between the individual shift points and the respective gears are drawn in.

Claims

1. Device for detecting the position of two axial movements of a transmission control, several cam paths (21, 22, 23) being formed on a shaft along which an extension (52) of a feeling lever (50) slides, the movement of the extension (52) being converted into an output signal with the aid of a sensor characterised in that, a second (21) and a third (23) cam path are located, viewed in the axial direction of the shaft on both sides of a first cam path (22) to which the neutral position of the transmission control is allocated, with a surface running around the central point of the shaft (11) in a circular direction, that the second (21) and the third (23) cam path have sections one behind another, viewed in the circumferential direction of the shaft to which the gears of the transmission control are allocated, and that the transition between the cam paths (21, 22, 23) is designed as a ramp (25, 26).

2. Device according to Claim 1, characterised in that the cam paths (21, 22, 23), viewed in the axial direction of the shaft (11) have the same lengths.

3. Device according to one of the Claims 1 or 2, characterised in that the cam paths (21, 22, 23) have several sections (31, 32, 33) or (41 to 45), whose beginning and end points have different radii (R1 to R8) viewed from the central point M of the shaft (11) respectively.

4. Device according to one of the Claims 1 to 3, characterised in that the second cam path (21) has a smaller radius than the third cam path (23). Device according to one of the Claims 1 to 4, characterised in that the sections (41 to 45)of the third cam path (23) cover a smaller angular dimension than the sections (31, 32, 33) of the second cam path (21).

6. Device according to one of the Claims 1 to 5, characterised in that the second cam path (21) has a section which has the radius of the first cam path (22).

7. Device according to one of the Claims 1 to 6, characterised in that the three cam paths (21, 22, 23) viewed in the axial direction of the shaft (11) have an at least partially cylindrical shape.

8. Device according to one of the Claims 1 to 7, characterised in that the uneven gears and the reverse gear are allocated to the third cam path (23) and that the even gears of the transmission control are allocated to the second cam path (21).

9. Device according to one of the Claims 1 to 8, characterised in that the tip (52) of the feeling lever (50) has a spherical shape.