WO2004063588A1

WO2004063588A1 - Clutch accelerators

Info

Publication number: WO2004063588A1
Application number: PCT/IB2003/006349
Authority: WO
Inventors: Yannick Frank Theophile Emile Christiaen; Wennael Droguet
Original assignee: Automative Products France S.A.
Priority date: 2003-01-10
Filing date: 2003-12-29
Publication date: 2004-07-29
Also published as: GB0300514D0; DE10394028B4; AU2003288471A1; DE10394028T5

Abstract

A clutch actuator (10) in which an actuating component (15) moves relative to a body (11) to actuate an associated vehicle clutch and the actuator includes a sensor (22) for measuring the position of the actuating component relative to the body. The sensor (22,23) is located on the actuator body (11) by the interaction between abutments (28) on the sensor and abutments (27a,27b) on the body. Typically the sensor (23) is located between a pair of arms (26) on the body (11) with each arm having a pair of abutments (27a,27b) between which an abutment (28) on the sensor is located. A further removable abutment (32,33) on the actuator body may be arranged to contact the sensor (23a) during transit to a vehicle assembly line to prevent retraction of the actuator (10) during transit.

Description

CLUTCH ACTUATORS

This invention relates to clutch actuators (hereinafter referred to as being of the type described) in which an actuating component (typically a hydrauhcally operated piston) moves relative to a body to actuate an associated vehicle clutch, the actuator also including a sensor for measuring the position of the actuating component relative to the body.

One example of a clutch actuator of the type described is a so-called concentric slave cylinder (CSC) in which an annular piston moves in an annular body which surrounds a gearbox input shaft and is used to operate the associated vehicle clutch.

Actuators of the type described are particularly useful when the vehicle clutch is not operated manually such as when an automated manual transmission is employed in which the clutch is operated automatically by a clutch actuating system.

It is an object of the present invention to provide an improved form of clutch actuator of the type described.

Thus according to the present invention there is provided a clutch actuator of the type described in which the sensor is located on the body by the interaction between abutment means on the sensor and on the body.

Typically the sensor or body may include first abutment means which is insertable between spaced second abutment means on the body or sensor.

The body may include a pair of arms which are circumferentially spaced around the body with the sensor located circumferentially between the arms.

Each arm on the body may include a first or second abutment means for interaction with the second or first abutment means of the sensor. Preferably the first and second abutment means interact to locate the sensor both axially and radially relative to the actuator body.

The sensor may be fixed to the body by quick attach formations on the first and second abutment means which snap into an interlocking relationship when the first abutment means is inserted between the second abutment means.

Alternatively, for example, the first and second abutment means may be ultrasonically welded together.

When the actuator is in transit from the actuator manufacturer to the vehicle production line it is desirable to prevent the piston retracting relative to the body to avoid the actuator becoming axially compressed and, for example, the piston possibly becoming disengaged from the body. This can conveniently be achieved by third abutment means associated with the piston which contacts fourth abutment means associated with the sensor thus preventing retraction of the piston.

Typically the third or fourth abutment means is removable after installation of the actuator in the vehicle to enable normal operation of the actuator.

The third abutment means may comprise a removable pin or clip carried on the piston which contacts the fourth abutment means provided by an end of the sensor.

For example, the third abutment means may be provided by a fork-like clip which embraces and clips under part of the body which carries a clutch release bearing, this fork-like clip contacting the end of the sensor.

Typically the sensor is of the Hall Effect or magnetic type in which a fixed part of the sensor is mounted on the actuator body and a magnetic member is carried on the piston with the position of the piston relative to the body being indicated by movement of the magnetic member relative to the fixed part of the sensor. In such an arrangement there may be no contact between the magnetic member and the fixed part of the sensor.

The invention also provides a clutch actuator of the type described in which the sensor has a fixed part for mounting on the body or piston and a moveable slider extending from the fixed part for connection with the piston or body so that the movement of the slider relative to the fixed part of the sensor indicates the position of the piston relative to the body.

In such an arrangement, the contact between the slider and the component connected thereto may comprise an abutment on the component or slider located between a pair of axially spaced abutments on the slider or component so that axial movements of the component also moves the slider. The contacting regions of these abutments are preferably shaped to allow limited axial misalignment between the piston and body without affecting the position signal generated by the sensor.

Several embodiments of the present invention will now be described, by way of example only, with reference to the accompanying drawings in which:-

Figure 1 is an axial section through a clutch actuator in accordance with the present invention in a retracted condition;

Figure 2 shows a perspective view of part of the actuator of figure 1 in an extended or transit position;

Figure 3 and 4 show perspective views of a transit clip used in the actuator of figures 1 and 2;

Figure 5 shows part of a position sensor used in the actuator of figure 1;

Figure 6 is a perspective view of part of the body of the actuator of figure 1 on which the sensor of figure 5 is located; Figure 7 shows a cross section of part of the actuator body of figure 1;

Figure 8 shows an alternative form of sensor connection for use in the actuator of figure 1;

Figure 9 shows a section through the sensor connection arrangement of figure 8;

Figures 10 and 11 show perspective views of an alternative form of transit clip arrangement for use in the actuator of figure 1 ;

Figure 12 is a perspective view of the transit clip used in figures 10 and 11;

Figure 13 is a still further form of transit arrangement suitable for the actuator of figure 1;

Figure 14 is a view of a transit pin used in the arrangement of figure 13;

Figure 15 shows a yet further form of clip arrangement for use in the transportation of the actuator of figure 1;

Figures 16 and 17 show perspective views of the clip used in the arrangement of figure 15;

Figures 18 and 19 show details of an alternative sensor attachment using ultrasonic welding;

Figures 20 and 21 show perspective views of an alternative form of sensor arrangement, and

Figures 22 and 23 show details of the arrangement shown in figures 20 and 21.

Referring to the drawings, an actuator in the form of a concentric slave cylinder 10 is shown in figures 1 to 6. This actuator comprises an annular body 11 formed from an outer plastics part 12 and an inner sheet metal part 13 which define an annular working bore 14 therebetween in which an annular plastics piston 15 is slideable. The sliding contact between the piston 15 and bore 14 is sealed by annular seal 16 which defines a working chamber 17 ahead of piston 15. A compression spring 18 operates between piston 15 and annular outer body part 12 and a rubber sealing boot 19 also acts between these components. An annular clutch release bearing 20 is carried within piston 15 as indicated diagrammatically in figure 1. An inlet pipe 21 is connected with outer body part 12 via port 12a to communicate with working chamber 17.

As is conventional, actuator 10 is operated by the admission of pressurised fluid into working chamber 17 via inlet pipe 21 from an associated master cylinder. This causes piston 15 to be displaced upwardly as viewed in figure 1 thus forcing release bearings 20 to displace a conventional diaphragm spring finger arrangement (not shown) on an associated vehicle clutch.

h accordance with the present invention, the actuator 10 includes a sensor 22 of the Hall Effect type which comprises a fixed part 23 and an axially movable part in the form of a magnet 24 which is moulded into a flange 25 which is formed integrally with plastics piston 15. Flange 25 includes a pair of spaced arms 26 which extend on opposite sides of fixed sensor part 23 and prevent rotation of the piston 15 and associated clutch release bearing 20.

The sensor 22 is located relative to the outer body part 12 by a pair of circumferentially spaced arms 27 formed integrally with body part 12 and best seen in figure 6. Each of the arms 27 includes axially spaced abutments 27a and 27b which define a slot 27c therebetween. The slot 27c is closed at one end by a web 27d. The sensor portion 23 has formed on opposite sides thereof a further abutment formation 28 best seen in figures 5 and 7. This formation includes a deflectable portion 28a which when the abutment 28 is introduced into slot 27c snaps into a cut-out 27e to locate the sensor relative to the outer body portion 12. The sensor is located axially by the slots 27c and radially by the webs 27d.

As will be appreciated, as the piston 15 and hence the magnet 24 moves axially relative to the fixed sensor part 23 the signal generated from the sensor 22 is transmitted to an associated processing means via a cable connector 29. This position signal can be used for a variety of applications. For example, the position signal can be used for controlling the position of a clutch in an automatic clutch control system, or for providing an anti-phase clutch vibration damping arrangement as disclosed in the Applicant's co-pending UK Patent Application No. 03 00515.4 or the clutch diagnostic/clutch position indicating system also disclosed in the above referred to co-pending UK Patent Application.

Figures 8 and 9 show an alternative arrangement for connecting fixed sensor part 23 to outer body part 12 in which the arms 27 shown in figure 6 are still utilised but the abutment formation on fixed sensor part 23 is of the form shown at 30 in figures 8 and 9 and has a deflectable latch portion 30a which snaps into cut-out 27e when abutment 30 is introduced into slot 27c.

Thus both the arrangements shown in figures 1 to 7 and in figures 8 and 9 are of the quick attach snap connection type in which the sensor is quickly and accurately located relative to the outer part 12 of the actuator body.

In a still further sensor attachment arrangement shown in figures 18 and 19 the fixed part 23 of the sensor has parallel sided abutment formations 31 formed thereon which slide into straight sided slots 27c formed in the arms 27 of the outer body part 12. The abutment formations 31 are then ultrasonically welded into slots 27c to complete the attachment of the sensor to the actuator body.

A further feature of the present invention is that the axial length of the actuator during transit from the actuator manufacturer to the vehicle assembly line is controlled by various arrangements which act on the fixed part 23 of the sensor.

Thus referring to figures 2 to 4 the flange 25 is provided with a removable transit clip 32 which clips over arms 26 and includes an abutment 33 for contact with the end 23a of the fixed part 23 of the sensor 22. Thus with the transit clip 32 in the position shown in figure 2 the axial length of the actuator cannot be reduced during transit. This prevents the actuator being compressed to, for example, the position shown in Figure 1 in which the end of the metal part 13 is exposed and which might therefore allow the metal part 13 to be pushed out of the actuator leading to damage of the unit.

Once the actuator has been installed in its operational position in the vehicle the clip 32 is removed by pulling in the direction X of figure 2 so that the actuator can operate normally.

An alternative transit clip arrangement is shown in figures 10 to 12 in which one of the arms 26a contacts a removable transit clip 34 which is located on the end of the fixed part 23 of sensor 22. Arm 26a contacts shoulder 34a of clip 34. The clip is removable after installation of the actuator by pulling the clip in the direction of the arrow Y of figures 10 and 12.

A yet further form of transit arrangement is shown in figures 13 and 14 in which arms 26a and 26b carry a transit pin 35 which extends through holes 37 in arms 26a and 26b and contacts the end 23 a of fixed sensor part 23. After fitting of the actuator in its operational position the pin 35 is withdrawn in the direction of arrow Z to allow normal operation of the actuator.

A still further form of transit arrangement is shown in figures 15 to 17 in which a fork-like clip 36 which embraces and clips under the release bearing containing portion 15a of piston 15 (see Figure 1). The clip 36 includes an abutment 36a which contacts the end 23a of the fixed portion 23 of the sensor and a handle portion 38 which is used to withdraw the fork-like clip after installation of the actuator by pulling in the direction R of figure 15.

A yet further form of sensor is shown in figures 20 to 23 in which the sensor 40 is screwed or otherwise secured to a portion 41 of the outer actuator body 12 by screws 42. The sensor includes a slider 43 having a pair of axially spaced abutments 44 formed on the end thereof which extend on opposite sides of an abutment 45 formed integrally on the piston 15. Thus as the piston moves axially the slider 43 is drawn into and out of the body portion 40 by the movements of abutment 45 and the following movements of abutments 44. Figures 22 and 23 show the shape of the co-operating abutments 44 and 45. The abutment 45 is parallel sided whereas the abutments 44 have domed portions 46 formed thereon which allow limited tipping of the slide 43 relative to the abutment 45 consequent on axial misalignment of the piston 15 relative to the body of the actuator. These minor misalignment movements do not cause movement of the slide 43 relative to the fixed portion 40 of the sensor and do not therefore provide misleading position signals from the sensor.

Claims

1) A clutch actuator of the type described in which the sensor is located on the body by the interaction between abutment means on the sensor and on the body.

2) An actuator according to claim 1 in which the sensor or body includes first abutment means which is insertable between spaced second abutment means on the body or sensor.

3) An actuator according to claim 1 or 2 in which the body includes a pair of arms which are circumferentially spaced around the body with the sensor located circumferentially between the arms.

4) An actuator according to claim 3 in which each arm on the body includes a first or second abutment means for interaction with the second or first abutment means of the sensor.

5) An actuator according to claim 4 in which the first and second abutment means interact to locate the sensor both axially and radially relative to the actuator body.

6) An actuator according to claim 4 or 5 in which the sensor is fixed to the body by quick attach formations on the first and second abutment means which snap into an interlocking relationship when the first abutment means is inserted between the second abutment means.

7) An actuator according to claim 4 or 5 in which the first and second abutment means are ultrasonically welded together.

8) An actuator according to any one of claims 1 to 7 in which third abutment means associated with the piston contacts fourth abutment means associated with the sensor thus preventing retraction of the piston during transit to a vehicle assembly line, one of the third or fourth abutment means being removable to allow subsequent operation of the actuator..

9) An actuator according to claim 8 in which the third abutment means comprises a removable pin or clip carried on the piston which contacts the fourth abutment means provided by an end of the sensor.

10) An actuator according to claim 9 in which, the third abutment means is provided by a removable fork-like clip which embraces and clips under part of the body which carries a clutch release bearing, this fork-like clip contacting the end of the sensor.

11) An actuator according to any one of claims 1 to 10 in which the sensor is of the Hall Effect or magnetic type in which a fixed part of the sensor is mounted on the actuator body and a magnetic member is carried on the piston with the position of the piston relative to the body being indicated by movement of the magnetic member relative to the fixed part of the sensor.

12) An actuator according to any one of claims 1 to 11 in which the sensor has a fixed part for mounting on the body or piston and a moveable slider extending from the fixed part for connection with the piston or body so that the movement of the slider relative to the fixed part of the sensor indicates the position of the piston relative to the body.

13) A clutch actuator of the type described in which the sensor has a fixed part for mounting on the body or piston and a moveable slider extending from the fixed part for connection with the piston or body so that the movement of the slider relative to the fixed part of the sensor indicates the position of the piston relative to the body.

14) An actuator according to claim 12 or 13 in which the contact between the slider and the component connected thereto may comprise an abutment on the component or slider located between a pair of axially spaced abutments on the slider or component so that axial movements of the component also moves the slider.

15) An actuator according to claim 14 in which the contacting regions of the abutments are shaped to allow limited axial misalignment between the piston and body without affecting the position signal generated by the sensor.

16) An actuator of the type described constructed and arranged substantially as hereinbefore described with reference to and as shown in figures 1 to 7 or 8 and 9 or 10 to 13 and 14 or 15 to 17 or 18 and 19 or 20 to 23 of the accompanying drawings.