DE102004005731A1 - wiper bearing - Google Patents

Abstract

The invention relates to a wiper bearing for a windshield wiper system with a bearing housing (12) with an outer tube forming the bearing housing (12) and an inner tube (24) arranged concentrically therewith and a journal (12) arranged on a bearing area (14). 30) for receiving a sinker tube (40). DOLLAR A It is proposed that outside the pin (30) in the region of its end face (36) to a pin (30) coaxially arranged ring member (16) is provided.

Description

The Invention is based on a wiper bearing according to the preamble of Claim 1.

One Wiper bearing housing serves to support a wiper shaft, the positioning of a Wiper axis and the mounting receptacles for mounting in a vehicle. Especially with snow load or in case of blocking occur mainly in the transition area between wiper bearing housing and Blade tube high forces and moments on.

From the DE 199 25 292 A1 is a wiper system is known in which the sinker tube in the transition region has an enlarged cross-section, which reduces the specific load in the critical transition region and increases the bending and torsional rigidity.

Advantages of invention

It It is proposed that in a wiper bearing according to the invention outside a provided for receiving a sinker tube pin is provided for pin coaxial annular element. Of the Pin is fixed to a bearing housing forming an outer tube the wiper bearing connected or arranged with a concentric Inner tube. By a form-fitting Connection of the sinker tube with the pin are forces of the bearing housing transferred to the journal and torsional forces. The pin takes over now mainly tensile forces, compressive forces and torsional forces. The ring element and its connecting struts take over bending moments and Bending forces. The pin is mechanically less stressed and more uniform overall. The ring member can substantially absorb bending forces in a Acting plane, which is formed from a bearing axis and the pin. The sinker tube is supported by the ring member and the pin accordingly relieved. On the pin itself occur only low bending loads on. It is also possible, to provide two coaxially arranged ring elements. In this case, the outer ring element has a very big stability and facilitates the connection of the sinker tube with the pin. With a connection of the pin on the inner tube, the construction is special compact. The force is applied both to the inner tube as well as on the outer tube.

by virtue of The low load may have a transition geometry between the pin and its bearing on the bearing housing are easily executed at a shortened Distance between a connection area between pin and sinker tube and the La gerbereich the pin on the inner tube or outer tube of the bearing housing. The wiper bearing, in particular a plastic wiper bearing, can be shorter and be made more compact as previous plastic wiper bearings, where on a long and harmonic transition area had to be respected, occurring there mechanical stress peaks to reduce. Due to the compact design of the wiper bearing can the circuit board tube closer be brought to the storage area of the wiper axis, resulting in a stiffer Overall system yields. Due to the uniform mechanical load of the bearing housing can this evenly thin-walled be executed what kind of an execution the wiper bearing made of plastic is particularly advantageous to at its preparation to avoid voids in the plastic. Farther becomes a shorter one cooling and cycle time in the production allows. Associated with the reduced Dead weight is the wiper bearing with ring element inexpensive to produce and assemble. The sinker tube can be made with a small cross-section, what a weight reduction and a smaller space requirement means. wiper carrier relieve with a smaller cross-section of the sinker tube elastic deformation, for example in a case of blocking, all Components of the wiper system - too the wiper lever can be made possible by further cost savings, because these components can be made easier.

At the Operation of the wiper system occurs through the arrangement of the ring element and the improved support of the sinker tube in the bearing area less movement, and also at high loads, the joint does not fail. The orientation of the Wiper shaft remains virtually unchanged, so that after the Design fixed angle of attack of the wiper blade to the vehicle window maintained and thus a good wiping quality is ensured.

In spite of the preferred use of unreinforced plastics for the wiper bearing Due to the special geometry a high component stiffness and achieved an improvement in the rigidity of the overall system. Thus, the application of wiper drives with plastic wiper bearings be extended.

The bearing housing is beigesteif and can still be made of unreinforced, cost-effective materials. In the production can be worked with very simple sliders. Due to the design of the wiper bearing and the resulting tool structure are suitable as a material in addition to unreinforced plastics in principle, materials that are not so easy demolding, such as reinforced plastics or metallic diecasting materials, esp especially Zn, Mg, Al.

The Ring element is arranged connectionless to the pin on the bearing housing and therefore can largely keep the bending load away from the pin. Furthermore, the ring element is attached to the bearing housing with struts, through which the pin at least in a connecting region, in the board tube is connected to the pin, is accessible from the outside. On the one hand allows the preferred attachment with upper and lower struts a high Stiffness of the ring element strut assembly, on the other becomes both the manufacture of the wiper bearing and the connection simplifies the sinker tube with the pin, since the pin for corresponding Tools, such as crimping tools, are easily accessible from the outside.

is the ring element arranged axially in front of the pin, in particular without overlap with the pin on the front side, the wiper bearing can with a advantageous tool without ring core and a correspondingly simple and solid tool slides are made. This also allows a better tool cooling and core cooling in a preferred die casting or injection molding process. protrudes the pin in an alternative embodiment with an end face in the ring element, a demolding of hollow profiled cores and of the toroid in the same direction, for which only a single Tool slide is necessary.

is the journal relative an axial extent of the bearing housing is arranged approximately centrally the ring element supported on the bearing housing wide, and it occurs only a small Component distortion of the component during cooling after manufacture on what a high level of geometry and a good process capability brings with it. Alternatively, the pin can with respect to an axial extent of the bearing housing off-center, e.g. be arranged at a lower end of the bearing housing. Thereby is a broad support on the bearing housing possible.

Especially stiff, the wiper bearing can be performed when the pin having a trained as a hollow profile cross-section. This embodiment is particularly stiff. The for these hollow profiles necessary tool cores can be aligned so that they can be pulled towards the pin, so simultaneously with an annular Tool core for the generation of the ring element. Alternatively, the pin has a as T-carrier or double T-beam trained cross-section on. A Verbindungsgeo geometry can in two tool halves be generated or removed from the mold. The tool structure is particularly simple.

Advantageous is that a component geometry between the ring element and the Bearing is laterally demolded in its manufacture. This allows in addition to the already described simplifications of the tools that can be enclosed after pushing the circuit board tube this around the sinker tube with a preferred so-called crimping to connect with the pin. A good fit and a qualitative high quality of Connection between the sinker tube and pin is guaranteed. In this case, the sinker tube is plastically deformed and provided in it Pockets of the wiper bearing housing or the pin displaced. Usual tools for crimping can be used become.

drawings

The Invention will be described below in an embodiment with reference to the accompanying drawings explained in more detail. It show: show:

1 a wiper bearing with a short ring element with asymmetric connection via carrier profiles;

2 a wiper bearing with a short ring element with symmetrical connection with hollow profile cross-section;

3a . 3b a representation of sectional planes in the longitudinal direction (a) and perpendicular to a pin symmetry line (b);

4a . 4b a tool design and the separation of tool halves in a cross section with a hollow profile (a) and a cross section with T-beam profile (b);

5a . 5b a tool assembly (a) and a tool core with toroidal core (b);

6 a cross section through a wiper bearing with coverage of pin and ring element;

7a . 7b a tool assembly (a) and a tool core without toroidal core (b);

8th a cross section through a wiper bearing without overlap of pin and ring element;

9a - 9f Based on a cross section through the pin a procedure of a crimping process before (a) and after attaching a sinker tube (b), bringing the tool (c), enclosing the sinker tube with the tool (d), retracting the punch in the connection area between sinker tube and pin (e) and the finished compound (f);

10a . 10b a size comparison of a preferred wiper bearing (a) with a known wiper bearing (b);

11 a section through a wiper bearing designed as a double ring ring element;

12 an illustration of an assembly of wiper bearing and sinker tube; and

13 a comparison of component stiffnesses of a preferred wiper bearing according to the invention and two known wiper bearing with hollow profile pin and T-beam pin.

description the embodiments

The Invention is especially for Wiper bearing made of plastic suitable. In the figures are general for same Parts same reference numerals used.

1 shows a wiper bearing 10 for a windscreen wiper system with a bearing housing 12 and one at a storage area 14 on the bearing housing 12 arranged cones 30 and a short ring element 16 , The bearing housing formed by an outer tube 12 concentrically surrounds an inner tube 24 , The short ring element 16 is outside the pin 30 in the area of his face 36 arranged coaxially. spigot 30 and ring element 16 are with respect to an axial extent of the bearing housing 12 arranged off-center.

The ring element 16 is with upper struts 18 and lower struts 20 on the bearing housing 12 fastened by the pin 30 at least in a connection area 32 is accessible from the outside. In this connection area 32 will later a not shown sinker tube with the pin 30 connected. The aspiration 18 . 20 are designed here as a T-beam. The ring element 16 has no direct connection to the pin 30 , So that the unillustrated sinker tube in a small space between pins 30 and inner circumference of the ring member 16 on the cones 30 can be plugged. The clearance is such that the sinker tube both on the pin 30 as well as on the inner circumference of the ring element 16 can be present.

2 shows a wiper bearing 10 with a short ring element 16 with symmetrical connection of pins 30 and ring element 16 on the bearing housing 12 , Lower and upper struts 18 . 20 which the ring element 16 hold, have a hollow profile cross-section. spigot 30 and ring element 16 are with respect to an axial extent of the bearing housing 12 arranged approximately in the middle.

An illustration of cutting planes through the wiper bearing 10 is in 3a . 3b shown. 3a shows a section in the longitudinal direction of the pin 30 , It is recognizable that the pin 30 connectionless to the ring element 16 is. 3b shows a section perpendicular to a pin symmetry line. The pin 30 has a hollow profile, which has a centrally arranged reinforcing element, the lower and upper struts 18 . 20 that the ring element 16 hold, are also designed as hollow profiles.

4a . 4b shows a cross section of a preferred tool for the production of struts 18 . 20 and cones 30 as well as the separation of tool halves 50 . 52 of the tool. The inventive arrangement of the struts 18 . 20 and the pin 30 advantageously allows the use of a tool in the middle in the two tool halves 50 . 52 is divisible. 4a shows the tool with trained as a hollow sections struts 18 . 20 and a pin formed as a hollow profile 30 , 4b shows a variant of the tool designed as a T-beam profile struts 18 . 20 and cones 30 ,

5a . 5b shows a longitudinal section through a preferred tool design of a tool 60 ( 5a ) and an associated preferred tool slide 62 ( 5b ) for a training of cones 30 and striving 18 . 20 with hollow profiles. To demould the four hollow profiled cores, such as in 4a shown, is advantageous only a single tool slide 62 necessary, with toroidal core 64 and the hollow profiled cores can be demoulded in the same direction. The toroid 64 is necessary when pin 30 and ring element 16 cover, ie the front side 36 of the pin 30 in the ring element 16 protrudes. 6 shows a section through such a wiper bearing 10 with overlap of cones 30 and ring element 16 with pushed-on board tube 40 , In the overlap area is the sinker tube 40 stable between ring element 16 and cones 30 trapped.

A tool structure without ring core is in 7a . 7b shown. The tool structure of the tool 70 shows a shape for a shorter pin 30 as in 5a ( 7a ) and a tool core without ring core ( 7b ). As a result, a solid tool slide assembly is possible, also the tool and the tool core can be better cooled. The variant of such a wiper bearing 10 is in 8th shown as a cross section. A circuit board tube 40 is on a cone 30 deferred and at the same time by a ring element 16 includes. The pin 30 is shorter than in the embodiment in 6 and does not protrude into the ring element 30 in, which is axially before the pin 30 sitting.

9a - 9f illustrated by cross sections through pins 30 and striving 18 . 20 a procedure of a running as crimping process connection between pins 30 and sinker tube 40 , spigot 30 and striving 18 . 20 at the beginning of the connection shows 9a , 9b also shows that on the pin 30 deferred sinker tube 40 , Subsequently, on both sides of the pin 30 one tool part each 70 . 72 with stamp pairs 74 . 76 at the cones 30 introduced ( 9c ) until the of the sinker tube 40 enclosed cones 30 from the tool parts 70 . 72 is enclosed ( 9d ). This is possible due to the special wiper bearing geometry and very advantageous for the quality of the connection between pins 30 and sinker tube 40 , Subsequently, the stamp pairs 74 . 76 for generating a positive connection between wiper bearing or pin 30 and sinker tube 40 in the sinker tube 40 pushed. The stamp pairs 74 . 76 displace the pipe material into pockets provided on the pin 30 ( 9e ). 9f shows the finished arrangement after completion of the connection process. The sinker tube 40 is in the connection area (corresponding to connection area 32 in 1 and 2 ) positively with the pin 30 connected.

10a . 10b shows a size comparison of a preferred wiper bearing 10 ( 10a ) with a known wiper bearing 80 ( 10b ). The preferred wiper bearing 10 has a pin 30 on, on an inner tube 24 of the wiper bearing 10 is tethered, allowing an application of force to both the inner tube 24 as well as on the designed as an outer tube bearing housing 12 he follows. The storage area 26 of the pin 30 and the storage area 28 of the ring element 16 or the ring element 16 holding elements on the inner tube 24 is preferably concentric to a good roundness of the two storage areas 26 . 28 to ensure. In contrast, the well-known wiper bearing shows 80 a pin 82 , which must be considerably longer than in the inventive arrangement with a corresponding low bending stiffness and stress exaggerations under load.

11 shows a section through a wiper bearing 10 in which the ring element 16 is designed as a double ring. The double ring increases the stability of the ring element 16 , Furthermore, this is between tween the pin 30 and the pursuit 18 . 20 created a greater clearance, so that when connecting the sinker tube 40 with the pin 30 there is more space for a tool, in particular a crimping tool.

12 shows an illustration of an assembly of wiper bearings 10 and sinker tube 40 , The sinker tube 40 is in the connection area 32 positively with the pin 30 connected. pursuit 18 . 20 hold a ring element 16 which is the sinker tube 40 includes. The aspiration 18 . 20 are designed as hollow profiles.

The inventive design of a wiper bearing 10 brings a significant improvement in component stiffness with it. 13 shows a comparison of component stiffness of a preferred wiper bearing 10 and two well-known wiper bearing with hollow profile pin and T-beam pin similar to the execution in 10b ,

The lowest component rigidity has the known wiper bearing with the T-beam pin, which is clearly visible in curve C. Although a known wiper bearing with a hollow profile pin shows an improvement in component rigidity (curve B), the wiper bearing according to the invention 10 improved in component stiffness by more than a factor of 2. This is due, inter alia, to the fact that the distribution of the elastic stress is distributed very uniformly here on the journal, whereas in the case of the known wiper bearings local stress peaks occur, as analyzes by means of the finite element method (FEM) show.

Claims (11)

Wiper bearing for a windshield wiper system with a bearing housing ( 12 ) with a bearing housing ( 12 ) forming outer tube and a concentrically arranged inner tube ( 24 ) and one at a storage area ( 14 ) on the bearing housing ( 12 ) arranged pins ( 30 ) for receiving a sinker tube ( 50 ), characterized in that outside the pin ( 30 ) in the region of its end face ( 36 ) a pin ( 30 ) coaxially arranged ring element ( 16 ) is provided. Wiper bearing according to claim 1, characterized in that the ring element ( 16 ) connectionless to the pin ( 30 ) on the bearing housing ( 12 ) is arranged. Wiper bearing according to claim 1 or 2, characterized in that the ring element ( 16 with struts ( 18 . 20 ) on the bearing housing ( 12 ) is attached, through which the pin ( 30 ) at least in one connection area ( 32 ) is accessible from the outside. Wiper bearing according to claim 1 or 2, characterized in that the ring element ( 16 ) axially in front of the pin ( 30 ) is arranged. Wiper bearing according to claim 4, characterized in that the pin ( 30 ) with the front side ( 36 ) in the ring element ( 16 protrudes. Wiper bearing according to one of the preceding claims, characterized in that the pin ( 30 ) with respect to an axial extension of the bearing housing ( 12 ) is arranged approximately centrally. Wiper bearing according to one of claims 1 to 5, characterized in that the pin ( 30 ) with respect to an axial extension of the bearing housing ( 12 ) is arranged off-center. Wiper bearing according to one of the preceding claims, characterized in that the pin ( 30 ) on the inner tube ( 24 ) is attached. Wiper bearing according to one of the preceding claims, characterized in that the pin ( 30 ) has a cross-section formed as a hollow profile. Wiper bearing according to one of claims 1 to 7, characterized in that the pin ( 30 ) has a trained as a double-T-carrier cross-section. Wiper bearing according to one of the preceding claims, characterized in that a component geometry between the ring element ( 16 ) and the storage area ( 14 ) is laterally demolded during its manufacture.