WO2008095781A1

WO2008095781A1 - Wiping system with a single piece arm made of a composite material for the glass of an automotive vehicle

Info

Publication number: WO2008095781A1
Application number: PCT/EP2008/050790
Authority: WO
Inventors: Jean-Pierre Eustache; Vincent Izabel; Stevan Guernalec
Original assignee: Valeo Systemes D'essuyage
Priority date: 2007-01-30
Filing date: 2008-01-24
Publication date: 2008-08-14
Also published as: EP2132065A1; FR2911833A1; FR2911833B1

Abstract

The invention relates to a wiping system for the glass of an automotive vehicle, including a single piece brush carrier arm (1) made of a composite material and generally extending along an axis (XX') and driven in an alternating rotation about a wiping axis (YY') of a driving shaft (2) essentially orthogonal with the longitudinal axis (XX') of said arm (1), an end section (10) of the arm (1) being rotatingly connected to the driving shaft (2) by a connection mechanism (3). According to the invention, the wiping axis (YY') is oriented on the vehicle in an optimised direction, whereby the so-called path angle formed between the longitudinal axis (XX') of the arm (1) and the normal to the wiping angle (YY') varies as little as possible depending on the wiping angle, and the connection mechanism (3) includes means (33, 35, 36) for correcting the attack angle of the brush that control a rotation movement of the arm (1) about its longitudinal axis (XX') in order to allow a variation of the attack angle of the brush depending on the wiping angle and along a predetermined curve (C3).

Description

SINGLE-PIECE WIPING SYSTEM OF COMPOSITE MATERIAL FOR GLASS OF MOTOR VEHICLE

The present invention relates to a wiper system for a motor vehicle comprising a monobloc wiper arm made of composite material, rotated alternately around a scanning axis by a drive mechanism.

The document WO2006 / 032389 describes the use of a monoblock arm of composite material, of longitudinal general orientation, comprising a first so-called drive end section for connection to an alternating scanning drive shaft. , and a second end section said sweeping, intended to carry a wiper blade. In operation, the wiper blade is pressed against the windshield of the vehicle through the inherent elasticity of the arm conferred by the composite material.

By the physical principle of the composite material arm, it is necessary that the distance between, on the one hand, the connection point of the arm and the wiper blade at the second end section said sweeping and on the other hand, the surface of the windshield, remains constant during operation in alternating scanning. To do this, it would be appropriate for the variation of the angle of elevation, namely the angle formed by the longitudinal axis of the arm and the normal to the scan axis, to be as small as possible during the scanning of the shield. breeze, or even zero.

Furthermore, during the alternating sweeping, the angle of attack of the blade, namely the inclination of the blade at its point of connection with the sweeper arm relative to the normal to the surface of the bumper -brise, will also vary depending on the scanning angle, according to a curve of variation depending on the shape of the windshield and the orientation of the drive shaft of the system. To obtain quality wiping, it is necessary that the variation of this angle of attack is also controlled, that is to say the closest to a predetermined curve.

Thus, during the design of the wiper system, it is generally sought to optimize the system so that it allows to obtain simultaneous, in operation, an angle of elevation variation curve with respect to the scanning angle, and a variation curve of the angle of attack with respect to the scanning angle which are in accordance with predefined curves, or at least those that are as close as possible to the desired optimal variation curves.

For simple forms of windshield, it may be possible, with a wiper system as described above, to obtain curves of variation of the angle of elevation and angle of attack compliant by seeking an optimized orientation of the scanning axis of the drive shaft of the system.

Unfortunately, the often complex shape of windshields, especially in the case of so-called panoramic windshields, generally does not allow, by simply optimizing the orientation of the scanning axis, to obtain simultaneously the desired angle of attack variation curve and a near zero variation for the elevation angle, so that a compromise is generally satisfied. In this case, a curve of variation of the angle of attack corresponding to the expected result is generally obtained, but the variation curve of the angle of elevation is then not satisfactory.

The present invention aims to overcome the above drawbacks by proposing a monoblock system of composite material that simultaneously satisfies the two previous constraints related to the angle of elevation and the angle of attack. .

To do this, the object of the invention is a wiper system for a motor vehicle window, comprising a one-piece wiper arm of composite material of general orientation along a longitudinal axis, driven in alternating rotation around a scanning axis of a drive shaft, said scanning axis being substantially orthogonal to the longitudinal axis of said arm, an end section of said arm being rotatably connected to the drive shaft via a connecting mechanism, characterized in that the scanning axis is intended to be oriented, during the installation of the system on the vehicle, in an optimized direction thanks to which the so-called angle of the site formed between the longitudinal axis of the arm and the normal to the scan axis varies as little as possible according to the scanning angle, and in that the connecting mechanism comprises means for correcting the angle of attack of the blade controlling a rotation movement of the arm about its longitudinal axis so as to allow a variation of the angle of attack of the blade according to the scanning angle according to a predefined curve.

Thus, unlike the known system with a direct connection between the composite arm and the drive shaft, in which the best orientation of the scanning axis is sought which makes it possible to find a compromise between the variation curves for the angle of elevation and the elevation angle, the principle of the invention is to seek the best orientation of the scan axis for obtaining a curve of variation of the optimal angle of elevation, then of correct the resulting gradient of angle of attack variation curve.

In a preferred embodiment of the wiper system according to the invention, the connecting mechanism is a drive carrier comprising a housing intended to be mounted integral in rotation with the drive shaft around the scan axis, and a secondary shaft rotatably connected to the drive support, the end section of the composite arm being fixed at one end and in the extension of the secondary shaft, so as to form a unitary assembly for rotation of the housing around the scan axis, and free to rotate axially about the longitudinal axis.

Preferably, the correction means of the connecting mechanism comprise a cam profile extending in a plane substantially perpendicular to the scan axis on a cam member placed inside the housing, and a member of control secured to the secondary shaft, said part being intended to remain fixed and said control member being adapted to cooperate by sliding with the cam profile during rotation of the drive shaft.

The cam profile is for example a through groove formed in the thickness of the workpiece.

In this case, the control member advantageously comprises a lever extending radially relative to the assembly formed by the shaft secondary and the composite arm, a first end of which is fixed rigidly to the secondary shaft, the lever being positioned so as to pass through the groove forming the cam profile, the other end of the lever carrying a contact element engaging with the the cam profile.

The contact element is preferably slidably mounted along the lever, and cooperates with an elastic member so as to ensure its contact with the cam regardless of the angular position of the assembly formed by the secondary shaft and the composite arm relative to its longitudinal axis.

Other features and advantages of the invention will be better understood from the following description of a non-limiting example of a wiper system according to the invention, with reference to the accompanying figures, in which :

- Figure 1 is a partial perspective view of the wiper system according to a possible embodiment of the invention;

FIG. 2 is an exploded view of the system of FIG. 1;

- Figure 3 is a partial cutaway perspective view of the wiper system of Figure 1;

FIG. 4 illustrates an example of curves of variation of the angle of attack and the angle of elevation obtained with or without the wiping system of the invention.

For ease of understanding, the elements common to all of the figures bear the same references. It should be noted that the various representations are only partial, in that all the constituent elements of the wiper system are not systematically represented for obvious reasons of clarity. This is particularly the case of the driving device of the drive mechanism, and the wiper blade.

With reference to FIGS. 1 to 3, a wiper system for a motor vehicle window includes an arm 1 of a monoblock-type wiper made of a composite material, of general orientation along a longitudinal axis XX '. This arm 1 is intended to be driven in alternating rotation by a drive shaft 2 whose YY 'said scanning axis is substantially orthogonal to the longitudinal axis XX' of the arm 1. To do this, a first end section 10 of the arm, said drive, is rotatably connected to the drive shaft 2 by means of a connecting mechanism 3.

According to a first important characteristic of the invention, a first step is to optimize the orientation of the scanning axis YY 'so as to obtain, in operation on a given vehicle, a variation of the angle depending on the scanning angle that is as low as possible, for example less than 2 degrees. This optimization phase can be performed by simulation, and of course depends on the vehicle on which the wiper system is to be mounted, including the shape of the windshield of the vehicle, and the location of the bodywork on which drive shaft will be mounted.

This phase of optimization of the orientation of the scan axis will nevertheless degrade the curve of variation of the angle of attack of the blade.

According to another important feature of the invention, this degradation is corrected by the fact that the connecting mechanism 3, in addition to its function of linking to rotation around the scan axis YY 'the arm 1 with the shaft 2, also comprises means for correcting the angle of attack controlling a rotational movement of the arm 1 around its own longitudinal axis XX 'so as to allow a variation of the angle of attack of the blade. function of the scanning angle according to a predefined curve and thus controlled.

In the preferred embodiment as shown in Figures 1 to 3, the connecting mechanism 3 is in the form of a drive carrier for mounting rotatably mounted to the shaft of the invention. drive 2 around the scan axis YY '. This drive support is preferably in the form of a housing 30 closed by a cover 31, with adapted coaxial openings 32a, 32b (FIG. 2) making it possible to fit the support on the drive shaft 2. The end section 10 of the composite arm 1 is fixed at one end of a secondary shaft 33, in the extension of this secondary shaft 33, itself fast to rotate with the drive carrier 3. The assembly formed by the secondary shaft 33 and the brush holder arm 1 is rotatably connected to the housing around the scanning axis YY ', while being free to rotate axially around the longitudinal axis XX '.

The connection mechanism or drive carrier 3 further comprises a cam part 34 placed inside the housing 30, coaxially with the scanning axis YY ', and intended to be fixed rigidly at the level a point of attachment of the vehicle through a bracket not shown.

When the wiper system is in place on the vehicle, the rotation of the drive shaft 2 about the scan axis YY 'must rotate the drive carrier 3 while the piece forming cam 34 remains fixed.

The means of correction of the angle of attack controlling the rotational movement of the composite arm 1 about its longitudinal axis XX 'are formed of elements carried partly by the secondary shaft 33, and partly by the cam member 34.

More specifically, these correction means comprise:

on the one hand, on the piece 34, a cam profile 35 extending in a plane substantially perpendicular to the scanning axis YY ';

- On the other hand, a control member 36 integral with the secondary shaft 33, and which is able to cooperate by sliding with the cam profile 35.

In the preferred embodiment illustrated, the cam profile 35 is in the form of a through groove formed in the thickness of the fixed part 34. The cam profile 35 is a function of the surface of the cam -brise to wipe and correction of the angle of attack to bring, and in particular has non-concentric areas relative to the scan axis YY 'corresponding to the areas of the windshield for which it is desired that the angle Wiper blade attack varies.

The control member 36 is formed, as shown in particular in Figure 2 in exploded form, a lever 37 extending radially relative to the assembly formed of the secondary shaft 33 and the composite arm 1 and positioned to pass through the groove in the assembled position (see Figure 3). One end 38 of this lever 37 is rigidly fixed (for example screwed) to the secondary shaft 33. The other end, located from the other side of the through groove when the system is assembled, carries a contact element 39 (see Figure 2) preferably mounted free in axial rotation on the lever 37, in engagement with the cam profile 35. The element contact 39 is preferably of substantially spherical shape, complementary to the section of the through groove forming the cam profile 35. This contact element 39 is also advantageously slidably mounted along the lever 37, and preferably associated with a elastic element (not shown), so as to ensure its contact with the cam profile 34 regardless of the angular position of the assembly formed by the secondary shaft 33 and the composite arm 1 relative to its axis XX '. The sliding assembly notably makes it possible to compensate for the variations in distance between the attachment point of the lever 37 on the secondary shaft 33 on the one hand, and the point of contact of the control member 36 on the cam profile 35 when the control member slides on this cam profile.

Other embodiments for the cam profile 35 on the one hand, and the control member 36 on the other hand, are of course achievable without departing from the scope of the present invention, from the moment where the sliding of the control member 36 along the cam profile 35 is able to control the axial rotation of the composite arm 1.

The rotational mobility of the arm 1 about its axis XX 'is further guided by means of a guide means, made in the example by two rings 40, 41 fixed in the housing 30, distributed on the along the secondary shaft 33 and surrounding said secondary shaft.

The embodiment as described is particularly simple and compact. This example may nevertheless undergo some variants without departing from the scope of the present invention. In particular, the secondary shaft 33 has been described as being part of the connecting mechanism 3, the composite arm 1 being fixed, by knurling, by pinching, or other type of attachment, at the free end of the shaft secondary 33. Alternatively, it could also be considered that the secondary shaft 33 is part of the composite arm 1.

In addition, other connection mechanisms allowing both the rotary drive of the composite arm 1 about the scan axis YY ', and the rotational drive of the same arm around its own longitudinal axis XX' in order to correct the angle of attack, are also possible.

FIG. 4 illustrates an example of curves obtained in simulation, making it possible to understand the interest of the wiper system according to the invention.

As previously indicated, an optimization phase consists in finding the best orientation of the scanning axis YY 'allowing to obtain an optimal curve for the variation of the elevation angle as a function of the scanning angle. The reference curve C1 corresponds to this optimal curve obtained. The reference curve C2 illustrates the variation of the angle of attack as a function of the scanning angle which would then be obtained if the system did not comprise, according to the invention, means for correcting the angle of rotation. attack. Thus, it can be seen that it has been possible to find an optimal orientation of the scan axis making it possible to obtain a curve of variation of the angle of elevation in accordance with what one is looking for, with very low values of variation, but this was done at the expense of the curve of variation of the angle of attack of the broom. Curve C3 finally illustrates the variation of the angle of attack obtained thanks to the action of the correction means according to the invention. It is found that this curve is well contained in an imposed template (represented by the dashed boundaries on either side of the horizontal axis).

The wiper system according to the invention thus makes it possible to simultaneously meet the requirement imposed by the use of a monoblock arm made of composite material, and to the constraints related to variations in the angle of attack for the first time. obtaining a quality wiping.

In the foregoing, the wiper system has been described in the very favorable case where it is possible to provide that the axis of rotation XX 'extends perpendicularly to the scan axis YY'. Nevertheless, some motor vehicles do not allow this arrangement, and the system may be such that the axis of rotation XX 'is not perpendicular to the axis scanning YY '.

Claims

claims

A wiper system for a motor vehicle window, comprising a one-piece wiper arm (1) made of a composite material of general orientation along a longitudinal axis (XX '), rotated alternately about a scanning axis ( YY ') of a drive shaft (2), said scanning axis being substantially orthogonal to the longitudinal axis (XX') of said arm (1), an end section (10) of said arm (1) being linked to rotation with the drive shaft (2) via a connecting mechanism (3), characterized in that the scanning axis (YY ') is intended to be oriented, when in place of the system on the vehicle, in an optimized direction by which the so-called site angle formed between the longitudinal axis (XX ') of the arm (1) and the normal to the scan axis (YY') varies as little as possible depending on the scanning angle, and in that the connecting mechanism (3) comprises means (33, 35, 36) for correcting the angle of for driving the arm (1) about its longitudinal axis (XX ') so as to allow a variation of the angle of attack of the blade as a function of the scanning angle according to a predefined curve (C3).

Wiper system according to claim 1, characterized in that the connecting mechanism (3) is a drive carrier comprising a housing (30) adapted to be mounted to rotate with the drive shaft (2). ) about the scanning axis (YY '), and a secondary shaft (33) rotatably connected to the driving support (3), the end section (10) of the composite arm (1) being fixed to a end and in the extension of the secondary shaft (33), so as to form an integral assembly rotating the housing around the scan axis (YY '), and free to rotate axially about the longitudinal axis (XX ').

3. Wiper system according to claim 2, characterized in that the correction means of the connecting mechanism (3) comprise a cam profile (35) extending in a plane substantially perpendicular to the scan axis (YY ') on a cam part (34) placed inside the housing (30), and a control member (36) integral with the secondary shaft (33), said part being intended to remain fixed and said member control (36) being slidably engageable with the cam profile (35) during the rotation of the drive shaft (2).

4. A wiper system according to claim 3, characterized in that the cam profile (35) is a through groove formed in the thickness of the piece (34).

Wiper system according to claim 4, characterized in that the control member (36) comprises a lever (37) extending radially with respect to the assembly formed by the secondary shaft (33) and the composite arm (1), a first end (38) of which is rigidly attached to the secondary shaft (33), the lever being positioned to pass through the groove forming the cam profile (35), the other end of the lever (37) carrying a contact element (39) engaging with the cam profile (35)

6. Wiper system according to claim 5, characterized in that the contact element (39) is substantially spherical in shape, complementary to the cross-section of the groove forming the cam profile (35).

7. Wiper system according to any one of claims 5 or 6, characterized in that the contact element (39) is slidably mounted along the lever (37), and cooperates with an elastic element so to guarantee its contact with the cam profile (34) regardless of the angular position of the assembly formed by the secondary shaft (33) and the composite arm (1) with respect to its longitudinal axis (XX ').

8. A wiper system according to any one of claims 2 to 7, characterized in that the end section of the arm (1) composite is fixed to the secondary shaft by knurling.