WO2007036420A1

WO2007036420A1 - Wiper blade

Info

Publication number: WO2007036420A1
Application number: PCT/EP2006/066126
Authority: WO
Inventors: Hans Braun; Paul Wynen; Wim Buseyne; Wim Verboven; Sven Wolfgarten
Original assignee: Robert Bosch Gmbh
Priority date: 2005-09-28
Filing date: 2006-09-07
Publication date: 2007-04-05
Also published as: DE102005046587A1; KR20080063281A; JP2009509836A; KR101323184B1; JP4778559B2

Abstract

The invention relates to a wiper blade (10) comprising a wiping strip (24) that encompasses a tilting wedge (38) and a rear (34) which are interconnected via a tilting web (36). Additional webs (42) are disposed laterally from the tilting web (36). The wiper rubber has a hardness not exceeding 64 Shore and has a coefficient of friction of less than one or is provided with a specific type of rubber while the distance between the webs varies.

Description

wiper blade

State of the art

The invention relates to a wiper blade according to the preamble of the independent claims.

In the case of such wiper blades with a spring-band-like support element, this is intended to ensure the most uniform possible distribution of the wiper blade contact pressure on the window starting from the wiper blade over the entire wiping area swept by the wiper blade. By a corresponding predetermined curvature of the unloaded support element - so if the wiper blade rests only with its two ends on the disc - the ends of the wiper blade completely applied to the disc wiper strip are loaded by the then tensioned support member to the disc, even if the Radii of curvature of spherically curved vehicle windows at each

Change the wiper position. The curvature of the wiper blade must therefore be somewhat stronger than the strongest curvature measured in the wiping field on the window to be wiped, because during wiping operation the wiper strip or its wiper lip resting against the window must always press against the window with a certain force. The support element thus replaces the complex mounting bracket construction with two arranged in the wiper strip spring rails, as practiced in conventional wiper blades (DE-OS 15 05 397), because the support element in addition to the distribution of the contact pressure also causes the necessary transverse reinforcement of the rubber-elastic wiper strip. In the known wiper blade namely the force exerted by a wiper arm on a main bar, directed to the disc bearing force is transmitted to two claw straps and distributed by these four claws on the rubber-elastic wiper strip.

In wiper blades with spring-elastic support elements, the support element has a spring elasticity in the direction of the vehicle windows and a certain flexural rigidity in the direction of the wiping movement. In working position, the wiping sheet is loaded in the direction of the vehicle window through the contact force of the wiper arm, wherein the wiper lip rests against the vehicle window.

When wiping a force generated by the pivoting force acts laterally on the rubber profile. While the wiper blade back is moved by the lateral force, the wiper lip initially remains in its position. In this case, the thin web between the wiper strip back and the Umlegkeil acts as a tilting joint because of its high elastic deformability, so that the wiper lip on Umlegkeil occupies approximately an angle of 55 degrees to the glass surface. This towing position is the working position of the wiper lip. The Umlegkeil is in this

Position tipped so far that it rests with its outer upper shoulder on the underside of the wiper strip back. Due to the oscillating wiping movement of the windshield wipers, reversal points result in the end positions of the movement. Here, the Umlegkeil works in the opposite direction and then takes back a dragged working position. As a result of this folding-over process, a disturbing folding-over noise occurs, in particular in the case of wiper blades with a spring-elastic support element. In addition, the squeegee is deformed very strong elastic in the area of the tilting bridge. In the course of the operating time, this leads to a permanent deformation of the wiper-rubber profile, which at first only affects the wiping action of the windshield wiper, but later can even prevent it from folding over.

A wiper strip is known from DE 9104461.8 U1, in which a damping strip is provided between the wiper strip back and the abutting shoulder of the reversing wedge. When the reversing wedge of the wiper strip folds over at the point of reversal, the shoulder first strikes against the damping strip and presses it until it touches the wiper strip back. As a result, the impact speed is slowed down and the noise attenuated when folding. In wiper blades with elastic support elements, however, this damping is not always sufficient. Especially with very long wiper blades that works

Umklappgeräusch disturbing.

Advantages of the invention

The wiper blade with the features of the main claim has the advantage that the lateral arranged by the tilting web additional webs the Umlegevorgang continuously attenuate by exerting on the reversing wedge with increasing inclination an increased compressive force on one side or an increased tensile force on the other side. This is on the one hand, as desired, prevents the shoulder of the Umlegkeils at full speed against the shoulder of the wiper strip back bouncing, whereby the disturbing Umklappgeräusch can be effectively prevented, on the other hand causes the constant force on the Umlegkeil located in the towing position that the transfer as such takes place safely at the point of inflection. Especially with wiper blades, which have been exposed to environmental influences for a long time, problems can occasionally occur here. This measure is complemented by the fact that a soft squeegee is used. This is possible because the webs also take on an additional support function, without which the tilting bar would endure the load only for a short time with a soft squeegee. If the subjective perception of noise can already be reduced to a quarter by using the bars, these values are reduced by the same factor by using a soft squeegee.

It has been shown that the hardness of the wiper blade rubber of less than 64 Shore can be selected by the use of the webs. With this hardness, a significant reduction in subjective noise perception already occurs in connection with the webs, the wiper strip remains in its mechanical values in the areas which ensure a long service life. Compared to comparable wiper strips without webs and slightly greater hardness can u. U. even a life extension can be expected. If the hardness is between 50 and 60 Shore, further noise reduction is possible without noticeably reducing the lifetime.

If you select wiper blades that have a hardness between 54 and 58 Shore, with an optimum at 56 Shore, the subjective perception of the Umklappgeräuschs can be reduced to the hearing limit, but still the wiping behavior overall and the life of the wiper blade more than acceptable stay.

Another way to reduce the folding noise is to vary the distance of the webs to each other along the wiper blade. In this case, it is advantageous if, in the region of high forces, that is to say in the region of the terminal Direction of the web density higher, the distance is therefore less than in the region of at least one end of the wiper blade. Again, the mechanical stability of the wiper blade is rather improved and still reduces the Umklappgeräusch. In the most frequently occurring case that the connection device is arranged in a central region of the wiper blade, it is thus advisable to increase the distance from this central region to the ends of the wiper blade.

It has been found that by a combination of a wiper blade with webs in the tilting region and a surface of the wiper blade, which has a friction coefficient with the disc, which is less than 1, also the subjectively perceived volume of the folding noise can be reduced. This reduction can be enhanced if the coefficient of friction is 0.8 or in particular 0.6.

Also by a special selection of the material of the wiper strip in connection with the webs in the tilting area, the volume of the Umklappgeräusches can be influenced. In a preferred case, the squeegee consists essentially of polychloroprene. Even if the squeegee contains at least one of the substances EPDM, CR or natural rubber, the folding noise can subjectively be reduced subjectively.

drawing

In the drawing show:

1 shows a wiper blade according to the invention in perspective

Representation with dash-dotted lines indicated wiper arm,

FIG. 2 shows a wiper strip enlarged with respect to FIG. 1 with an indicated support element, FIG. 3 shows a section along the line III-III in FIG. 2,

FIG. 4 shows a variant according to FIG. 3,

FIG. 5 shows a view along the arrow V in FIG. 2,

FIG. 6 shows a variant of the detail VI in FIG. 5,

FIGS. 7 and 8 variants for FIG. 6 and FIG. 9 further variants for FIG. 1. Description of the embodiments

A wiper blade 10 shown in FIG. 1 has a strap-like, elongated, spring-elastic, one-part or multi-part support element 12, which is curved in the longitudinal direction in the unloaded state. At the of the to be wiped

Disc 14 remote from the convex upper or outer band side 16 (Figures 1 and 2) of the support member is disposed in the central portion thereof, for example, flat against this terminal device 18, with the help of the wiper blade 10 with a guided on the bodywork of a motor vehicle, driven wiper arm 20th can be releasably connected. An elongated, rubber-elastic wiper strip 24, which extends longitudinally parallel to the support element 12, is arranged on the concave lower or inner band surface or band side 22 of the curved support element 12 facing the disc. At the free end of the wiper arm, counterconnection means (not shown in more detail) are provided, which are connected to the connection device 18 of the

Wischblatts in the sense of a joint interact.

The wiper arm 20 and thus also the wiper blade 10 are loaded in the direction of the arrow 26 to be wiped disc, whose surface to be wiped is indicated in Fig. 1 by the dotted line 14. Since the dot-dash line is intended to represent the strongest curvature of the disk surface, it is clearly evident that the curvature of the still unloaded wiper blade 10 resting against the disk 14 with its ends 10 'is greater than the maximum disk curvature. It has - unloaded - so with respect to the disc a concave course. Under the contact pressure (arrow 26), the wiper blade 10 sets with his

Wischlip performing wiper blade 28 over its entire length to the disk surface 14 and goes into a stretched position approximate working position. In the process, a tension builds up in the band-like, spring-elastic support element 12, which ensures a proper contact of the wiper strip 24 or its wiper lip 28 over its entire length on the vehicle window 14. Because the generally spherically curved disc does not represent a section of a spherical surface, the wiper blade 10 must constantly be able to adapt to the respective position and the course of the disc surface 14 relative to the wiper arm 20 during its wiping movement (double arrow 30). Therefore, the one swinging movement (double arrow 32) about the hinge axis of Connection connection enabling articulated connection between wiper arm 20 and wiper blade 10 necessary.

The wiper strip 24 shown in Figure 2 has a wiper strip back 34 which is connected via a tilting ridge 36 with a Umlegkeil 38, on the underside of the wiper lip 28 is arranged. Laterally of the tilting ridge 36 extend two longitudinal grooves 40, the upper side of the wiper strip back 34 and the underside of the Umlegkeil 38 are formed. Within the longitudinal grooves 40, distributed over the length of the longitudinal grooves 40, webs 42 provided, which are arranged laterally of the tilting web 36.

Each web 42 extends from the tilting web 36 starting laterally toward the open side of the longitudinal groove 40 and connects the wiper strip back 34 with the Umlegkeil 38. The webs 42 are part of the wiper strip 24 and therefore stoffschlüs- sig with the wiper strip back 34, the tilting bar 36 and the Umlegkeil 38 connected. However, it would also be conceivable to form the webs 42 separately and to introduce them into the longitudinal grooves 40.

According to the invention, a soft squeegee is selected as the material for the wiper strip 24. The hardness of squeegees are specified in the unit Shore, whose dimension is in principle an equivalent for a penetration of a standard body into the surface of the squeegee at a certain force. Conventional wiping gums have hardnesses greater than 64 shore. By the use of the webs 42 in the region of the tilting web 36, the stability of the wiper blade is increased overall, so that for the squeegee and hardnesses between 50 and 60

Shore, especially between 54 and 58 Shore can be selected. In the exemplary embodiment, the squeegee has a hardness of 56 Shore, with which a reduction of the Umklappgeräuschs is achieved on a sixteenth of the housing without webs and with harder squeegee.

If the volume of the Umklappgeräuschs specified in the known unit Sone, so the volume corresponds to a conventional wiper blade without bars and with normal hardness about 12 Sone. By inserting the webs in conjunction with a squeegee of hardness 56 Shore, the volume of the folding sound can reduce it to less than 1 Sone, which is slightly quieter than the ticking of an alarm clock. It can be seen in FIG. 3 that each web 42 extends perpendicularly from the tilting web 36 to the tilting web 36. Furthermore, it can be seen that the webs 42 are arranged on both sides of the tilting web 36. If the webs 42 of FIG. 3 are aligned on both sides of the tilting web 36, FIG. 4 shows the webs

42 of the two sides arranged offset.

The distance a of the webs 42 to each other should be between 10 mm and 50 mm and is preferably 20 mm. In the case of the staggered webs 42 of Figure 4 then results in a distance of 10 mm, if the

Webs 42 viewed on both sides of the tilting ridge 36. Over the length of the wiper strip 24, the webs 42 are evenly distributed. However, it is also conceivable, for. B. for reasons of resonance, the distance a over the length of the wiper strip 24 to vary.

As shown in FIG. 1, the distance a varies such that in the middle region of the wiper blade, that is to say in the region of the connecting device 18, the distance is smaller and increases towards the ends of the wiper blade 10. Thus, the distance al is smaller than the distance a2, this smaller than the distance a3 and this in turn smaller than the distance a4. Of course, the number of webs is not limited to the number shown in the embodiment, but also depends in particular on the length of the wiper blades.

As shown in Figure 2, there is a friction between the squeegee and the disc 14 with a coefficient of friction R. In Figure 2, the wiper blade is shown in a standing position and not in a towed position. In the exemplary embodiment, the surfaces of the wiper blade rubber are such that the friction between the disc 14 and the squeegee rubber is determined by a coefficient of friction R = 0.6. This is in conjunction with the webs 42 an optimal state. It is also conceivable to set values for R <0.8 or R <1.

The squeegee of the wiper strip 24 is in the embodiments substantially of polychloroprene. However, it can also contain one of the substances EPDM, CR or natural rubber. The tilting bridge 36 represents the actual operative connection between the wiper strip back 34 and the Umlegkeil 38 and must be dimensioned accordingly. The webs 42 are kept smaller in thickness d than the thickness D of the tilting web 36. In a preferred embodiment, the thickness d of the webs 42 is half the thickness D of the tilting web 36.

As mentioned, the webs 42 form a connection between the wiper strip back 34 and the Umlegkeil 38 and extend from the tilting ridge 36 to each open side of the longitudinal grooves 40. It is clear that it makes sense for manufacturing reasons, the webs 42 with the Kippsteg 36 to connect. It would also be conceivable, however, to leave a gap between the webs 42 and the tilting web 36. The situation is similar with the open sides of the longitudinal grooves 40. The webs 42 connect an outer edge 44 of the wiper strip back 34 in a straight line 45 with an outer edge 46 of the Umlegkeils 38, as shown in Figure 5.

In the figures 6 to 8 variants are shown for this purpose. In Figure 6, the connection of the two outer edges 44 and 46 is formed in the shape of a groove 48, which has the advantage of a low notch effect. The example shown in Figure 7 is one of three variants. The outer sides 50 of the webs 42 extend obliquely and are connected to only one of the outer edges 44 or 46. In this case, it is possible for all the webs 42 to extend obliquely from the outer edge 44 or from the outer edge 46 into the longitudinal groove 40 or alternatively in alternation from the outer edge 44 or the outer edge 46. In the further variant according to FIG 8, the outsides 52 are each

Bridge 42 in the respective longitudinal groove 40 is added. Consequently, they do not touch any of the outer edges 44 or 46.

The goal of reducing or even minimizing the flip-over noise of the wiper blade 10 is achieved with each of the variants according to FIGS. 5 to 8. By appropriate design of the outsides of the webs 42, it is possible to respond to different requirements. It is essential that the spring characteristic to be assigned to the webs 42 can be strongly influenced by the shape of the outside. For example, it can be made steeper or shallower or have a degressive or progressive course. It is also conceivable to different shapes of the outer sides of the webs 42 to each other combine. This can be done at successive webs 42 or within a web 42 at its outer edge.

FIG. 9 shows that the webs 42 are respectively formed on only one side 54 or 56, but on the opposite side 56 or 54 only rest or even have a small spacing. The training can also be made so that successive webs 42 are integrally formed on its upper side 54 and on its lower side 56 and free on the opposite side. In this way it is possible that, although a pressure force is exerted on the Umlegkeil 38 by the webs 42, starting from the wiper strip back 34, but a tensile force is omitted.

It is clear that in the case of wiper blades 10 with a plurality of stacking webs 36 arranged one above the other, corresponding webs 42 can be assigned to each of the tilting webs 36. Even with these higher-build wiper blades, it is thus possible to have a positive influence on the folding sound.

Claims

claims

1. wiper blade with a wiper strip (24), which comprises a Umlegkeil (38) and a Wischleistenrücken (34) which are interconnected via a tilting web (36), wherein laterally of the tilting web (36) additional webs (42) are arranged, characterized by a soft squeegee.

2. Wiper blade according to claim 1, characterized in that the hardness of the wiper blade rubber is less than 64 Shore.

3. Wiper blade according to one of the preceding claims, characterized in that the hardness of the wiper blade is between 50 and 60 Shore, in particular between 54 and 58 Shore, preferably at 56 Shore.

4. Wiper blade with a wiper strip (24), which comprises a Umlegkeil (38) and a Wischleistenrücken (34) which are interconnected via a tilting web (36), wherein laterally of the tilting web (36) additional webs (42) are arranged, in particular according to one of the preceding claims, characterized in that the webs (42) over the length of the wiper blade (24) are spaced apart from each other and the distance along the length of the wiper blade (24) varies.

5. Wiper blade according to claim 4, characterized in that the distance of the webs (42) in the region of a connecting device (18) have a smaller distance than in the region of at least one end of the wiper blade (10).

6. Wiper blade according to one of claims 4 or 5, characterized in that the connecting device (18) in a central wiper blade area is arranged and increases the distance of the webs from each other from this central region to the ends of the wiper blade (10).

7. Wiper blade with a wiper strip (24), which comprises a Umlegkeil (38) and a Wischleistenrücken (34) which are interconnected via a tilting web (36), wherein laterally of the tilting web (36) additional webs (42) are arranged, in particular according to one of the preceding claims, characterized by a surface of the wiper blade having a friction coefficient (R) with the disc, which is smaller one.

8. Wiper blade according to claim 7, characterized in that the surface of the wiper blade with the disc has a coefficient of friction (R) of less than 0.8, in particular equal to 0.6.

9. wiper blade with a wiper strip (24) having a Umlegkeil (38) and a

Wischleistenrücken (34) comprises, which are connected to each other via a tilting web (36), wherein laterally of the tilting web (36) additional webs (42) are arranged, in particular according to one of the preceding claims, characterized in that the squeegee substantially from Polychloroprene exists.

10. Wiper blade with a wiper strip (24), which comprises a Umlegkeil (38) and a Wischleistenrücken (34), which are interconnected via a tilting web (36), wherein laterally of the tilting web (36) additional webs (42) are arranged, in particular according to one of the preceding claims, characterized in that the squeegee contains at least one of the substances EPDM, CR or natural rubber.