EP1037775A1

EP1037775A1 - Tube plate for a wiper system

Info

Publication number: EP1037775A1
Application number: EP99945892A
Authority: EP
Inventors: Kurt Muehlpforte; Jan Dietrich; Henk Becker; Tino Boos
Original assignee: Robert Bosch GmbH
Current assignee: Robert Bosch GmbH
Priority date: 1998-07-23
Filing date: 1999-07-03
Publication date: 2000-09-27
Also published as: JP2002521259A; DE19833159A1; WO2000005110A1; DE19833159B4; KR20010024229A

Abstract

The invention relates to a tube plate (10) for a wiper system which is provided as a support of wiper drive (18, 20) and as at least one wiper bearing (36) which is arranged in a tube socket (14, 68), said tube socket being situated at the end of a plate tube (12), in a cross-wise manner with regard to said plate tube. According to the invention, the plate tube (12) and the tube socket (14, 68) are manufactured as one piece, and the tube socket (14, 68) holds a bearing bush (40, 42, 44, 46, 48) in a play-free manner. Said bearing bush is comprised of an unset metal and is forcibly pressed into the tube socket (14, 68).

Description

Pipe board for an ischer system

State of the art

The invention is based on a tube board for a wiper system according to the preamble of claim 1.

Wiper systems for motor vehicles are fastened to the body of a motor vehicle with a wiper carrier, a so-called circuit board or tube board - if the wiper carrier also consists of tubes. The circuit board usually comprises a motor circuit board which carries a wiper drive with a wiper motor and a gearbox attached to it. An output shaft of the gearbox is mounted in a gear dome and usually drives cranks via a crank and articulated rods, which are firmly connected to a drive shaft for each windshield wiper. The drive shafts of the windshield wipers are mounted in wiper bearings, the bearing housings of which are attached to or molded onto the ends of the board. The circuit board is fastened to a vehicle body directly via the bearing housing or via fastening eyes which are formed on the bearing housing, on the circuit board and / or on the motor circuit board. As a rule, the boards are composed of many components. This leads to numerous interfaces with corresponding tolerances. From DE-GM 74 34 119 a tube board is known which is made from a square tube to which a plate serving as a motor board is welded. A wiper bearing is fixed to the ends of the square tube. Such tube boards or tube frame systems are very stable despite their light construction. For cost reasons, a straight support tube is sought which does not require a pre-bending operation.

From DE 29 20 899 C2, a tube board is known, tube connectors with corresponding approaches being inserted into the hollow profile of the platinum tube. The lugs lie at least partially on the walls of the platinum tube and have at least one recess into which portions of the platinum tube are pressed in order to form a positive connection between the platinum tube and the pipe socket. Wiper bearings are arranged in the pipe socket. Compared to screw connections, the number of parts is reduced, but the joining process still requires numerous prefabricated individual parts with many manufacturing steps. This makes warehousing and logistics more expensive. Furthermore, the massive approaches have a considerable weight despite the cutouts.

It is also from the magazine "Werkstatt und Betrieb", Carl Hanser Verlag Munich, 1995, pages 812 to 815, and the special print from the magazine "Metallumformtechnik", Claus Dannert Verlag, 1994, under the title "Precision Workpieces in Lightweight Construction, manufactured by hydroforming U ", a process for forming tubes into workpieces known. This process, which is mainly used for the motor vehicle industry, works with high pressures.

The pipe section to be formed is placed in a divided tool into which the desired workpiece shape is incorporated. A vertical press ram closes the tool, that is mounted in a press. The pipe ends are closed by closing tools, through which a pressure medium is fed, which presses the pipe walls against the inner mold. Axial pressure is applied to the tube by horizontally acting tappets, which is superimposed on the internal pressure. Thus, the material that is required for the forming is not only taken from the wall thickness of the pipe section, but also made available by shortening the pipe. The locking tools are axially adjusted during U-forming.

It has already been proposed in the patent application, DE-OS 196 42 666, to form pipe sockets for wiper bearings on a tube plate which is produced using an internal high-pressure process and to use one-piece or two-piece bearing bushes made of plastic or metal. The bearing bushes are held in the pipe socket by positive locking, friction locking or fabric locking. An axial positive connection exists e.g. in that the pipe socket is pressed into a recess in the bearing bush, for example a groove, in one area. It is also proposed that the bearing bush have on its periphery an area made of deformable material, which is delimited by an annular recess. During assembly, material can collect in the recess, which is peeled or deformed by the pressing process.

Advantages of the invention

According to the invention, the bearing bush is made of a set-free metal and is excessively pressed into the pipe socket which is integrally formed on the circuit board tube. In doing so, form the bearing bush and the pipe socket in the elastic range to such an extent that a play-free non-positive connection is maintained throughout the entire service life. In the context of the invention, non-settable material is understood to mean a material which, under the operating load, does not exceed the yield point and does not plastically deform to the extent that the non-positive connection is lost. The bearing bushes can be made in one piece or in several parts.

In order to compensate for larger tolerance ranges between the pipe socket and the bearing bushes and to be able to dispense with calibrating the inaccurate inner contour, it is expedient for the bearing bushes to have longitudinal teeth running in the axial direction on their circumference. The tips of the teeth dig more or less into the surface of the pipe socket, which creates a microstructural positive connection. Material displaced during assembly is taken up by the gaps between the teeth. In addition to steel, e.g. Suitable for aluminum and light alloys.

With suitable bearing materials, the bearing surfaces for the wiper bearings can be worked directly into the bearing bush. Otherwise, it is expedient to press a bush made of sintered material or plastic into the bearing bush or to inject a bearing layer made of plastic into the bearing bush.

As a rule, the frictional connection between the bearing bush and the pipe socket is sufficient for a positive locking of the bearing bush in the axial direction and in the circumferential direction during the service life. However, if extreme peak loads are to be feared, it is advisable to add an additional one positive locking should be provided, for example by pressing the edge of the pipe socket or part of it into a groove running transversely to the axial direction. If the groove is rotationally symmetrical, the bearing bush is only secured in the axial direction, while if the groove is not rotationally symmetrical, it can also be secured in the circumferential direction. Non-rotationally symmetrical profiles of the ring groove can be achieved in a simple manner by one or more flattening of the ring groove in the area of the groove base or the groove flank against which the pipe socket rests. Even with a shallow indentation, sufficient security against twisting and axial displacement is achieved.

Since the material is pressed against a tool surface in the case of internal high-pressure processes, the outer contours of the circuit board tube are very precise, while the inner contours can have larger tolerances due to the material flow, which is difficult to control. It is therefore advantageous if the bearing bush is centered on the precise outer surface of the pipe socket.

According to one embodiment of the invention, the bearing bush is guided in a sleeve for this purpose, each of which overlaps the pipe socket with a collar at its ends and is centered on the outer circumferential surface of the pipe socket. You can in this area by gluing, soldering, welding or the like. cohesively connected to the pipe socket. Another possibility is that the pipe sockets have inwardly bent areas at their ends. These can already be molded on during the internal high-pressure process or can be molded on in further work steps according to the internal high-pressure process, in that the closed sides of the pipe sockets are centrally perforated or slotted and the resultant edges are bent inwards. Due to its good elasticity in form, the area that is bent inwards results in a permanent force fit.

The bearing bush can also be axially fixed via the drive shaft by placing it between a collar, e.g. a crank of the drive shaft, and a thrust washer on the drive shaft axially fixed and axially fixed relative to the pipe socket by the crank and a locking ring which is embedded in the bearing bush.

The tube board is attached to a vehicle body by means of screws. For this purpose, the sinker tube is advantageously extended beyond the pipe socket. The extension contains a cross hole into which decoupling elements made of rubber-elastic material are inserted. A spacer sleeve is provided to limit the elastic preload. To facilitate assembly, the decoupling elements can be attached to the spacer sleeve. It is expedient that the transverse bore is extended to a slot open to the end face of the circuit board tube, so that the decoupling elements can be inserted with the spacer sleeve from the end face.

The transverse bore can be arranged rotated as desired about the longitudinal axis of the plate tube, so that the tube plate is suitable for many installation situations with slight modifications.

The tube board can also be attached to the vehicle body using additional fastening elements. For example, it may be advantageous to have an angular fastening element that has an opening for receiving decoupling elements has to be molded directly onto the bearing bush, or to be plugged onto the extension of the circuit board tube and firmly connected to it. Here too, fastening points can be realized with a few changes in an angular range of 360 ° around the bearing axis or around the longitudinal axis of the plate tube.

drawing

Further advantages result from the following description of the drawing. Exemplary embodiments of the invention are shown in the drawing. The drawing, the description and the claims contain numerous features in combination. The person skilled in the art will expediently also consider the features individually and combine them into useful further combinations.

Show it:

Fig. 1 shows a schematic longitudinal section through a tube plate,

Fig. 2 shows a plan view of a bearing bush according to an arrow II in FIG. 3, FIG. 3 3 shows a longitudinal section through a bearing bush according to line III-III in FIG. 2,

Fig. 4 shows a variant of FIG. 3,

Fig. 5 shows a partial longitudinal section through a sinker tube with a pipe socket and an inserted bearing bush,

6 shows a cross section along the line VI-VI in FIG. 5, FIG. 7 shows a variant of FIG. 5, 8 shows a variant of FIG. 7,

9 is a partial perspective view of one end of a circuit board tube.

10 shows a variant of FIG. 9,

Fig. 11 is a circuit board tube with a fastener and

Fig. 12 is a bearing bush with a fastener.

Description of the embodiments

An essential component of a tubular blank 10 is a blank tube 12, which was formed from a tubular blank in an internal high-pressure process. The sinker tube 12 consists of generally suitable metallic materials, in particular steel with and without surface coating and stainless steel. It has molded pipe sockets 14 and 16. In the pipe socket 16, a wiper drive consisting of a wiper motor 18 and a gear 20 is held by means of a gear dome 22 provided on the housing of the gear 20. An output shaft with a crank 26 is mounted in the transmission dome 22, the ball pins 30 of which are connected to ball pins 28 on cranks 24, which are fixedly connected to the drive shafts 32, via rods (not shown). The drive shafts 32 carry wipers (not shown in detail) at their ends 34 and are mounted in wiper bearings 36 at the ends of the circuit board tube 12. The wiper bearing 36 essentially contains a bearing bush 40 made of a non-settable material, for example steel, aluminum or a light metal alloy, which is pressed into the pipe socket 14 in excess. 2 and 3 show an embodiment of the bearing bush 40 with a collar 50 and longitudinal teeth 54 on the jacket. During assembly, in which the bearing bush 40 is pressed into the pipe socket 14, the tips of the toothing press into the pipe socket 14, displaced and peeled material can be taken up by the spaces 56 of the longitudinal toothing. 3, a bearing surface 52 is machined directly into the bearing bush 40, in the case of a bearing bush 42 according to FIG. 4 the drive shaft 32 is pressed into a bushing 58 made of sintered material. Instead of the bushing 58, a bushing made of plastic can also be provided or - as FIG. 6 shows - a bearing layer can be injected into a bearing bushing 44.

In general, the force-fit connection is sufficient to secure the bearing bush 40, 42, 44, 46 and 48 axially and in the circumferential direction in the pipe socket 14, 68 of the sinker tube 12. However, in order to be able to absorb extreme peak loads, it is advisable to provide additional positive locking devices. In the embodiment according to FIG. 5, the bearing bush 44 rests on the one hand with the collar on an end face of the pipe socket 14, while on the other hand the edge 66 of the pipe socket 14 is pressed into a groove 60 de bearing bush 44 by means of an embossing tool. The bearing bush 44 is thus axially secured with respect to the circuit board tube 12. In order to secure the bearing bush 44 also in the circumferential direction, the groove 60, as shown in FIG. 6, has a flattened area 64. As a rule, a flat area 64 is sufficient, however, several flattened areas or other non-circular courses of the groove 60 can also be provided.

It is important that the contour against which the edge 66 of the pipe socket 14 is pressed has a non-rotationally symmetrical cross-sectional profile. 7 and 8, the bearing bush 46 is additionally axially secured by the drive shaft 32, on the one hand, on the crank 24 and on the other hand on a thrust washer 76, which axially by means of a locking ring 78 in an annular groove 80 of the drive shaft 32 is secured. Compared to the pipe socket 68 and 14, on the one hand, it is axially secured by the crank 24 and, on the other hand, by a locking washer 74 which is embedded in the bearing bush 46.

The pipe socket 68 according to FIG. 7 has an inwardly bent edge 70 which holds the bearing bush 46. Since the surface of the edge 70 facing the bearing bush 46 was formed by a precise tool surface, close tolerances can be maintained. Furthermore, the edge 70 with its arc 72 has great elasticity in terms of form, so that the frictional connection between the pipe socket 68 and the bearing bush 46 is ensured over the entire service life.

The edge 70 can be made in various ways. One possibility is that a corresponding indentation is already formed in the area of the pipe socket 68 during the internal high-pressure process and only the passage for the bearing bush 46 is subsequently opened. Another possibility is that the pipe socket 14, which is initially closed by the high-pressure process, is provided with a central hole 86 on the front side and the inwardly projecting edge is bent over by a pressing tool, the hole 86 being widened accordingly. A further possibility is to introduce a cross slot 88 into the closed end face of the pipe socket 68 and to bend the flaps 90 thus created inwards. Since the tabs 90 on their ren free ends do not form a closed ring, they are radially particularly elastic.

8 shows a sleeve 82 in which the bearing bush 46 is pressed. The sleeve 82 has at its ends a collar 84 which covers the end of the pipe socket 14 and with which the sleeve 82 is centered on the outside of the pipe socket 14. The collar 84 is expediently firmly connected to the pipe socket 14 by gluing, soldering, welding or the like.

In order to fasten the tube plate 10 to a vehicle body, the tube plate 12 is extended beyond the tube socket 14, 68. A transverse bore 108 is provided in the extension 38, into which rubber-elastic decoupling elements 92 are tied. A spacer sleeve 94 is inserted through it, which rests with a collar 96 on a decoupling element 92 and is supported with its other end on the body when a predetermined tensioning path is reached. The purpose of this is that the decoupling elements 92 and the circuit board tube 12 are not pressed together inadmissibly during assembly. For length compensation, the spacer sleeve 94 has an elongated hole 110. In order to adapt to structural conditions, the transverse bore 108 can be arranged rotated by an angle about the longitudinal axis of the circuit board tube 12.

The decoupling elements 92 can also be firmly connected to the spacer sleeve 94. In order to be able to mount them in this case as well, the transverse bore 108, as shown in FIG. 10, is extended to a slot 98 which is open to the end face of the circuit board tube 12, so that the spacer sleeve 94 is also included in the decoupling elements from this side 92 can be inserted. In order to be free in the choice of the fastening point on the body of the vehicle, it is expedient to plug an angular fastening element 100 onto the extension 38 of the circuit board tube 12, which has an opening 104 for receiving a decoupling element 92. The fastening element 100 can be arranged in the extension 38 in any angular position about the longitudinal axis of the circuit board tube 12. It is non-positively, positively or materially connected to the circuit board tube 12.

The variant according to FIG. 12 shows a fastening element 102 which is formed directly on the bearing bush 48 and has an opening 106 for receiving a decoupling element 92. The fastening element 102 can be arranged in any angular position about the bearing axis of the bearing bush 48 by the bearing bush 48 being mounted in the pipe socket 14 in a rotated manner.

reference numeral

10 tube board 58 socket

12 circuit board tube 60 groove

14 pipe socket 62 bearing layer

16 pipe sockets 64 flattening

18 wiper motor 66 edge

20 gear 68 pipe socket

22 Getriebedom 70 bent edge

24 crank 72 sheets

26 crank 74 lock washer

28 ball studs 76 thrust washer

30 ball pins 78 circlip

32 drive shaft 80 ring groove

34 end 82 sleeve

36 wiper bearings 84 collar

38 extension 86 holes

40 bearing bush 88 cross recess

42 bearing bush 90 rags

44 bearing bush 92 decoupling element

46 bearing bush 94 spacer sleeve

48 bearing bush 96 collar

50 frets 98 slit

52 bearing surface 100 fastener

54 Longitudinal teeth 102 Fastening element Gap 104 opening opening cross hole fastener elongated hole

Claims

Expectations

1. tube board (10) for a wiper system as a carrier of a wiper drive (18, 20) and at least one wiper bearing

(36), which is arranged in a pipe socket (14, 68) at the end of a plate tube (12) transversely thereto, characterized in that the plate tube (12) and the tube socket (14, 68) are made in one piece and the Pipe socket (14, 68) holds a bearing bush (40, 42, 44, 46, 48) free of play, which consists of non-settable metal and is pressed into the raw socket (14, 68) in excess.

2. Pipe board (10) according to claim 1, characterized in that the bearing bush (40) carries on its periphery an axial toothing (54).

3. Pipe board (10) according to one of the preceding claims, characterized in that a bushing (48) made of sintered material or plastic is pressed into the bearing bush (42).

4. Pipe board (10) according to one of the preceding claims, characterized in that a bearing layer (62) made of plastic is injected into the bearing bush (44).

5. Pipe board (10) according to any one of the preceding claims, characterized in that the bearing bush (44) at one end has a collar (50) and at the other end a groove (60) extending transversely to the axial direction, into which an edge

(66) of the pipe socket (14) is pressed.

6. Pipe board (10) according to claim 5, characterized in that the groove (60) is an annular groove with a non-rotationally symmetrical profile.

7. Pipe board (10) according to claim 6, characterized in that the annular groove (60) has at least one flattening (64) in the circumferential direction.

8. Pipe board (10) according to one of the preceding claims, characterized in that the pipe sockets (68) have inwardly bent regions (70) at their ends.

9. Pipe board (10) according to one of claims 1 to 7, characterized in that the bearing bush (46) in a sleeve

(82) is guided, each with a collar (84) on their

Ends overlaps the pipe socket (14) and is centered on the outer circumferential surface of the pipe socket (14).

10. Pipe board (10) according to one of the preceding claims, characterized in that the bearing bush (46) is axially fixed via a drive shaft (32).

11. Pipe board (10) according to one of the preceding claims, characterized in that the circuit board tube (12) is made of stainless steel.

12. Pipe board (10) according to one of the preceding claims, characterized in that a fastening element (102) is integrally formed on the bearing bush (48).

13. Pipe board (10) according to claim 12, characterized in that decoupling elements (92) are provided between the fastening element (102) and a body screwing point.

14. Pipe plate (10) according to one of the preceding claims, characterized in that the plate tube (12) over the pipe socket (14, 68) is extended and in the region of the extension (38) a transverse bore (108) for receiving decoupling elements (92 ) having.

15. Pipe board (10) according to claim 14, characterized in that the transverse bore (108) is extended to an open to the end face of the circuit board tube (12) slot (98).

16. Pipe board (10) according to one of claims 14 or 15, characterized in that in the transverse bore (108) decoupling elements (92) are inserted through which a spacer sleeve (94) is inserted.

17. Pipe board (10) according to claim 16, characterized in that at least one decoupling element (92) with the spacer sleeve (94) is fixedly connected.

18. A method for producing a tube plate (10) according to any one of the preceding claims, characterized in that the pipe socket (68) made closed by an internal high-pressure process approximately in the middle of their end faces be punched and the hole area on at least one side is turned inside out and expanded.

19. A method for producing a tubular plate (10) according to any one of the preceding claims, characterized in that the pipe socket (68) made closed by the internal high-pressure process is centrally slotted on the end faces and the flaps (90) thus formed are bent inwards on at least one side .