Washing arrangement for motor vehicle shields, in particular for motor vehicle lamp shields.

State of the art

p0001The invention relates to a washing plant according to the preamble of the main claim. It's a car wash known (DE-PS 35 18 685), in which in a arranged in the piston or in the nozzle support section of the connecting line, a check valve is arranged, which only opens when the piston and thus the spray reaches its operating positions are.

ADVANTAGES OF THE INVENTION

p0002The car wash according to the invention with the characterizing Merkamalen of the main claim has the advantage that the piston forms a check valve in communication with the cylinder inner wall and the overflow channel, which only opens when the piston has almost reached its operating position. Likewise, the piston is pushed by the spring back to its resting position after stopping the conveyor, wherein the piston by a small path shuts off the overflow.

p0003The measures specified in the dependent claims, advantageous refinements and improvements of the main claim washer are possible.

drawing

p0004An embodiment of the invention is illustrated in the drawing and explained in more detail in the following description. 1 shows a schematic diagram of the front end of a motor vehicle, in which a car wash for the vehicle headlight is drawn schematically, Figure 2 shows a longitudinal section through a to the washing plant belonging, in the rest position spray in an enlarged view, Figure 3 shows a section through the spray of Figure 2 , along the line III-III in figure 2, figure 4 shows a longitudinal section through the in-service position, relative to the description of figure 2 rotated by 90 degrees spray and figure 5 shows a section through the spray according to figure 4, along the line VV in figure . 4

Description of the embodiment

p0005In a schematically illustrated in Figure 1 the front end of a motor vehicle headlight 10 12 are arranged, one of which is shown in FIG. 1 The headlamp 12 is a spray device 14 assigned to that part of a washer 16 for the cover plates of the motor vehicle lights 12th The washer 16 further comprises a reservoir 18 for the washing liquid and a delivery line 20 connects the reservoir 18 with the spray 14. On the conduit 20 is still as conveyor acting electrically operated pump 22 which is connected to the line 20 and with the reservoir is conductively connected. To operate the electric motor pump 22, the washer a power circuit 24 with a switch 27th In the arrangement shown in Figure 1, the spray device 14 in its so-called motor pump 22, the washer a power circuit 24 with a switch 26th In the arrangement shown in Figure 1, the spray device 14 in its so-called rest position, in which a spray for 14 belonging spray nozzle 26 is located within the body of the vehicle tenth If the washer is operated but by closing the switch 26, the nozzle 26 is brought into an operating position shown in broken lines in Figure 1, in which the out of the nozzle spray jet 28 detects the entire cover plate of the motor vehicle light 12th

p0006The construction of the spray device 14 can be seen in particular from Figures 2 to 4. FIG. It has as a housing on a frame fixedly arranged cylinder 32, which is tubular. One tube end is closed by a bottom part 34, while in the other pipe opening, a lid is placed 35th In the cylinder 32 a piston 36 is slidably disposed. Next is to the piston 36, a tubular nozzle carrier 38, which penetrates the cover 35, and at the free end 40, the spray nozzle is held 26th The tubular nozzle holder 38 has a smaller diameter than the piston 36. It is surrounded by a recess formed as a helical spring compression spring 42 biased at an annular shoulder 43 of the piston 36 on the one hand and on the cover 35 on the other hand is supported. Next, the piston 36 has a tubular portion 44 which extends in the direction of the cover 35th The sleeve-shaped projection 44 surrounding the compression coil spring 42. The free end surface 46 of the sleeve-shaped projection 44 is located at a distance 48 from the said end face 46 facing surface 50 of the lid 35, so that the piston 36 in the cylinder 32 by the dimension 48 within is of the cylinder 32 slidably. The cover wall 50 thus forms one of the end surface 46 of the lug 44 facing surface, which provides for a limitation of the piston stroke 48th It is clear that the pistons 36, 44 must be moved within the cylinder 42 against the force of the compression coil spring. As Figures 2 to 4 illustrate, are provided on the cylinder inner wall 52 four equally spaced, groove-like channels 55 arranged extending from the lid 35 from beyond the end face 46 of the lug 44 in the area of ​​the piston 36, 44th The sleeve-shaped extension 44 of the piston has two opposing projections 54 (Figures 2 and 3), which extend in two of the channels 55 and so for a rotationally fixed displacement of the piston 36, 44 and thus the spray nozzle 26 provide. Next is the part 36 of the piston 36, 44 a transverse bore arranged 56, which is conductively connected to the longitudinal bore 58 of the tubular nozzle carrier 38th The transverse bore 56 itself discharges on both sides in an annular groove 57 which is disposed on the jacket 60 of the piston part 36th This lateral surface 60 of the piston part 36 is appropriately performed on the cylinder inner wall 52, while the sleeve-shaped extension 44 of the piston has a certain play in the cylinder 32nd The projections 54 of the piston base 44 have in the longitudinal grooves 55 on a little play. As Figure 2 further shows the portion of the piston 36 is situated with its side remote from the nozzle carrier 38 side with its end face 62 at a sealing ring 64 on which is formed annularly and held on the inner circumferential surface 52 of the cylinder 32nd The configured as O-ring seal element 64 is in this case 34 at a distance from the cylinder base 34 held in place by an annular shoulder 66 of the cylinder base in an extension 68 of the cylinder inner wall 52nd This results in a so-called pressure chamber 7O, which is delimited by the end face 62 of the piston part 36, through the cylinder bottom 34 and by its approach 66th In this pressure chamber 7O flows, in particular Figure 4 shows a tubular connection piece 72, which is also part of the conveying line 20th Further, the spray means 14 nor a tubular bellows 74 having its one end connected to the lid 35 and the other end is connected to the spray nozzle 26th The operation of the washer 16 is described in detail below.

p0007For Cleaning the front of the headlight 12, the switch 27 of the washer 16 is closed and the feed pump 22 starts, promotes this liquid from the tank 18 via the supply line 20 into the pressure chamber 7O the spray 14. By taking place there pressurization of pistons 36, 44 and with this also the nozzle carrier 38 and the spray nozzle 26 is moved in the direction of arrow 75 against the force of the compression coil spring 42, until the end face 46 of the sleeve-shaped projection 44 comes against the end face 50 of the lid 35 to rest (figure 4 ). It put both of the pistons 36, 44 and the nozzle holder 38 and the spray nozzle 26 a stroke back, which is designated by 48. Thus, the spray nozzle 26 from its rest position shown in Figure 2 passes into the operating position shown in FIG. 4 Shortly before reaching the operating position, ie just before the interaction of the end face 46 of the piston base 44 with the end face 50 of the lid 35 are the piston 36, the channels 55 on a particular cut 51 free, so that they act as transfer channels and within the pressure chamber 70 liquid can flow into this. Via the annular groove 58, the washing liquid reaches the transverse bore 56 and flows through them into the central bore 58 of the tubular nozzle carrier 38. From this central bore 58 from reaches the washing liquid to the spray nozzle 26 where it emerges from the nozzle orifices 78, and as a spray jet 28 (Figure 1) on which comes to be cleaned disk. Because the radial projections 54 of the sleeve-shaped attachment 44 are disposed at the free end of the sleeve-shaped projection, are also called guide channels for the lugs 54 overflow ducts which connect the pressure chamber 7O with the transverse bore. For connecting line which 26 supplies the nozzles with the coming out of the storage tank 18 the washing liquid, thus include the feed pump 22, the feed pipe 20, the connection pipe 72, the pressure chamber 70, the transfer ducts 55, the annular groove 57, the transverse bore 56 and the central bore 58 the nozzle carrier 38th

p0008After the switch 27 open, the feed pump 22 is stopped and the compression coil spring 42 pushes the piston 36, 44 back into its initial position, wherein it is moved against the direction of the arrow 75th In its end position, the piston moves with its end face 62 against the O-ring 64 so that it forms a non-return valve which prevents that the system is idle. The design of the feed pump 22 is such that the piston 26, the washing liquid 36, 44 abruptly shifts to the closing of the switch by the dimension 48, so that a premature spraying washing liquid from the nozzle 26 is avoided. This is supported by the fact that the portion 36 of the piston releases the section 51 of the transfer channels 52 shortly before reaching the operating position (Figure 4).