DE102018209372A1 - Frost-resistant device for volume-controlled portioning of cleaning fluid - Google Patents

Abstract

The invention relates to a device (1) for volume - controlled portioning of cleaning fluid with a housing (2), a housing (2) arranged in the chamber (3) which in the radial direction by a substantially cylindrical lateral surface (4) and in the axial direction Essentially by a first (5) and a second end surface (6) is limited. In order to increase the resistance of the device against frost-related damage and to avoid damage due to ice formation, it is proposed according to the invention that at least one of the end faces (5, 6) is coupled axially in the direction of the chamber (3) to a stop (10) and in the opposite direction slidably provided.

Description

The invention relates to a device for volume-controlled portioning or dosing of cleaning fluid for a cleaning system installed in a motor vehicle, in particular for use in cleaning optical or optoelectronic apparatus.

Such devices are made, for example WO 2017194062 A1 are known and are used mostly for targeted, jerky delivery of defined amounts of a particular aqueous cleaning fluid when cleaning cameras for detecting vehicle environment in semi-or fully autonomous vehicle control systems. As a result, a particularly economical use of the cleaning fluid is achieved.

For this purpose, the device has a housing with a therein, filled with cleaning fluid chamber with a defined volume, which is displaced as needed in the direction of the object to be cleaned. This happens sequentially.

The housing of such a device is usually made of plastic. In the event of frost, the cleaning fluid in the chamber can freeze and expand. The resulting high forces can lead to permanent damage to components of the device and cause a loss of function - for example due to cracks. It can also result in the housing being stretched or stretched plastically in the long run. This changes the volume of the chamber and thus the tuning of the cleaning system and increases cleaning fluid consumption.

Against this background, the invention has the object to increase the resistance of the device against frost-related damage and to avoid damage due to ice formation.

This object is achieved by a device having features according to the main claim. Further developments and further embodiments of the invention will become apparent from the dependent claims and the following description and figures.

The invention provides that at least one of the end faces of the cleaning fluid-filled chamber located in the housing of the device is provided axially in the direction of the chamber against a stop and is displaceable in the opposite direction.

Thus, when freezing the cleaning fluid and its concomitant spatial expansion, the volume of the chamber is simply increased, allowing the ice to expand without exerting excessive pressure on the components of the device and damaging them.

According to the preferred embodiment, the end surface may be provided on a plug which is radially sealed inserted in the housing and slidably mounted in the opposite axial direction against a spring force, which automatically restores the original state after each frost-related expansion of the chamber during thawing.

According to the embodiment of the invention, the spring force can be generated by a spring element which is arranged biased in the axial direction between the plug and a housing fixedly fixed lid. As a result, the device can be offered in a comparatively simple construction in several variants and adapted exactly and flexibly to a wide range of loads and displacement movements.

According to the preferred embodiment, the spring element may comprise at least one axial wave spring, which is particularly well statically load cases suitable and can be realized with the high spring forces at a low height.

However, the spring element within the invention may also be formed with a simple and inexpensive coil spring or, for example, for particularly high loads, with disc springs.

According to the preferred embodiment of the invention, the lid can be positively connected to the housing for easy installation.

Particularly preferably, the cover is fixed with a latching connection on the housing, wherein the cover surrounds the housing radially in some regions on the outside and locks on the outside of the housing to form an undercut.

As a result, the assembly can be carried out particularly easily with only one insertion movement in any desired rotational position between the cover and the housing.

According to a further embodiment, the latching connection between the housing and the lid can be realized by the lid is inserted into the housing and locked by radially outwardly arranged locking elements in radial openings on the housing.

Another embodiment provides that the cover material-conclusive, fixed to the housing, in particular welded, whereby particularly compact outer dimensions of the device can be realized with a particularly strong connection at particularly low demands on dimensional and form tolerances.

According to the preferred embodiment of the invention, the stopper can be provided with a connecting piece with an internal channel for connecting a hydraulic supply line, wherein the lid is provided a central axial opening for the passage of the connection piece.

Thereby, the number of components and dimensions of the device can be reduced.

According to a further preferred embodiment, the cover may have a plurality of circumferentially distributed drainage openings for draining off water in its radial outer area, whereby the risk of ice formation in the spring chamber is significantly reduced.

The present invention will be explained in more detail below with reference to three of several possible embodiments. This show the 1 to 3 the embodiments 1 to 3 greatly simplified in axial section:

Fig. 1

An inventive device 1 has an approximately sleeve-shaped housing 2 with a cylindrical chamber ( 3 , The chamber 3 is in the radial direction through the lateral surface ( 4 ) and in the axial direction by two opposite end surfaces 5 and 6 limited and thus has a constructive volume V ,

In the chamber 3 is an axially movable piston 9 arranged, which against the lateral surface 4 through a sealing element 27 is sealed and in the initial state shown by a return spring 23 on abutment against the end face ( 5 is pressed. In the the piston 9 opposite end surface 6 there is an outflow opening ( 8th which leads to a spray nozzle, not shown.

In the operational state of the cleaning system is the entire volume of the chamber 3 between the piston 9 and the outflow-side end surface 6 filled with a cleaning fluid.

In the end area 5 there is an inflow opening ( 7 ). When switching on a pump, not shown, the cleaning fluid is in the chamber ( 3 ) under a pressure which is greater than the resistance of the return spring 23 , This will cause the piston 9 from its starting position towards the end surface 6 moves and displaces it in front of him in the chamber 3 amount of cleaning fluid from the chamber ( 3 ) into the outflow opening ( 8th ) and so to the spray nozzle, not shown. As soon as the piston 9 has passed through the entire travel path and arrived at its outflow-side stop, despite active pump no cleaning fluid more out of the chamber 3 repressed. After switching off the pump, the piston 9 by the return spring 23 returned to its original position and the chamber 3 is again filled with cleaning fluid, for example by overflow of the sealing element 27 or other suitable measure which does not form part of the present invention. This completes a cleaning sequence and a new cleaning sequence starts when the pump is reactivated. Inflow side is the chamber 3 axially through a plug 11 closed, which chamber side, the end surface 5 trains and at a stop 10 is applied. On the plug ( 11 ) is a connecting piece ( 18 ), which serves for connecting a line, not shown, leading from the pump and an internal, to the inflow opening ( 7 ) leading channel ( 19 ) having.

The stopper ( 11 ) is against the housing ( 2 ) by means of a sealing element 28 radially sealed and in the stop ( 10 ) or the chamber 3 slidably mounted opposite axial direction.

A spring element ( 12 ) exercises on the stopper 11 one in the direction of the chamber 3 directed spring force ( F ) and press this against the stop 10 , Here is the spring force F of the spring element 12 provided much higher than one from the return spring 23 on the piston 9 acting spring force, thereby ensuring that in normal operation of the plug 11 not by the piston 9 out of his by the stop 10 defined starting position and thereby the volume of the chamber 3 is enlarged.

Inflow side is on the housing 2 a lid 13 Fixed or fixed. In its center, the lid points 13 an axial breakdown ( 20 ), which from the connecting piece ( 18 ) is penetrated.

In the embodiment shown, the lid 13 by means of a weld 29 cohesively connected to the housing, wherein other types of connections within the invention are just as permissible as shown by way of example in subsequent embodiments.

Between the lid 13 and the stopper 11 is an annular spring chamber ( 21 ) educated. The spring element 12 is in the spring chamber ( 21 ) between the plug ( 11 ) and the lid ( 13 ) arranged biased in the axial direction.

When freezing, the cleaning fluid in the chamber 3 it freezes, expands and applies pressure to the inner walls of the chamber 3 out . Once the pressure is essentially the spring force F of the spring element 12 (As well as various frictional resistance such as. From the sealing element 28 ), the plug becomes 11 from the stop 10 away in the direction of the spring chamber 21 postponed. This increases the volume V the chamber 3 by the expansion factor of the cleaning fluid, the pressure increase due to ice formation is limited and does not exceed the strength values of the housing 2 and other components of the device 1 , The spring element 12 compressed at the same time. After thawing, the spring element shifts 12 the stopper 11 back to its original position at the stop 10 , which also provides the intended volume V the chamber 3 restored and the device is placed in the ready state.

In the embodiment shown, the spring element ( 12 ) as a coil spring ( 15 ), wherein within the invention, other types or combinations of different types of spring elements are permitted.

In the radial outer region of the lid ( 13 ) are several drainage breakthroughs ( 22 ) arranged. These connect the spring chamber ( 21 ) with the environment of the device 1 , are used for drainage of liquids from the spring chamber 21 and ensure that frost can not form in it at frost, which is the axial freedom of the plug 11 could prevent.

By a substantially regular distribution of drainage openings ( 22 ) in the circumferential direction when installing the device in the vehicle must not be paid to their angular position with respect to their central axis, because in the range of a possible water accumulation always a drainage breakthrough 22 will be available.

Fig.2

In the 2 is another embodiment of the device 1 shown. Unlike the execution after 1 is the lid 13 positive locking via a latching connection ( 17 ) with the housing 2 connected. The lid ( 13 ) is designed essentially pot-shaped with a bottom and a radial wall, with which he the housing ( 2 ) surrounds radially on the outside.

The housing 2 has a radially outwardly projecting collar 25 , which one of the lid 13 radially inwardly projecting locking element 24 is engaged behind under the formation of an undercut. As a locking element 24 are, for example, an inner bead, a tapered inner-facing Umlaufkragen or more distributed circumferentially arranged locking lugs or Rasthacken.

Furthermore, the spring element ( 12 ) as an axial wave spring ( 14 ) or constructed of a plurality of stacked axial shaft springs composite spring assembly.

Figure 3

In the 3 is another embodiment of the device 1 shown.

The lid 13 is also pot-shaped and has a locking connection 17 positively with the housing 2 connected, but here is the radial wall of the lid 13 from the case 2 enclosed radially on the outside. In the case 2 There are several radial breakthroughs 26 provided in which radially outward on the lid 13 arranged locking elements 24 intervene with the formation of an undercut.

The spring element 12 in the embodiment shown is as a plate spring package consisting of several stacked disc springs ( 16 ) built up.

LIST OF REFERENCE NUMBERS

1

device

2

casing

3

chamber

4

lateral surface

5

First endface

6

Second endface

7

inflow opening

8th

Bore

9

piston

10

attack

11

Plug

12

spring element

13

cover

14

Axial wave spring

15

coil spring

16

Belleville spring

17

locking connection

18

spigot

19

channel

20

Axialdurchbruch

21

spring chamber

22

Drainage breakthrough

23

Return spring

24

locking element

25

collar

26

Radial opening

27

sealing element

28

sealing element

29

Weld

F

spring force

V

Volume of the chamber

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• WO 2017194062 A1 [0002]

Claims (12)

Device (1) for volume-controlled portioning of cleaning fluid with a housing (2), a chamber (3) arranged in the housing (2) with a defined volume (V), with at least one inlet opening (7) opening into the chamber (3) for supplying cleaning fluid into the chamber (3), with at least one outflow opening (8) opening into the chamber (3) for removing cleaning fluid from the chamber (3), the chamber (3) being in the radial direction through a substantially cylindrical one Mantle surface (4) and in the axial direction substantially by a first, inflow-side (5) and a second, outflow-side end face (6) is limited, with a in the chamber (3) substantially between the end faces (5,6) axially displaceable and against the lateral surface (4) sealed provided piston (9) for displacing the cleaning fluid from the chamber (3) in the outflow opening (8), characterized in that at least one of the end surfaces (5,6) axially in Rich tion chamber (3) coupled to a stop (10) fixed and slidably provided in the opposite direction. Device (1) according to Claim 1 characterized in that the end face (5) on a plug (11) is provided, which in the housing (2) radially sealed and in a stop (10) opposite axial direction against a spring force (F) is displaceably mounted. Device (1) according to Claim 2 characterized in that the spring force (F) by a spring element (12) is generated, which is arranged between the plug (11) and a on the housing (2) fixed fixed lid (13) biased in the axial direction. Device (1) according to Claim 3 characterized in that the spring element (12) has at least one axial wave spring (14). Device (1) according to Claim 3 characterized in that the spring element (12) has at least one helical spring (15). Device (1) according to Claims 3 characterized in that the spring element has at least one plate spring (16). Device (1) according to at least one of Claims 3 to 6 characterized in that the lid (13) is firmly bonded to the housing (2). Device (1) according to at least one of Claims 3 to 6 characterized in that the cover (13) is positively fixed to the housing (2). Device (1) according to Claim 8 characterized in that the lid (13) with a latching connection (17) is fixed to the housing, wherein the cover (13) surrounds the housing (2) partially radially outward. Device (1) according to Claim 8 characterized in that the lid (13) with a latching connection (17) on the housing (2) is fixed, wherein the housing (2) of the cover (13) partially surrounds radially outwardly. Device (1) according to at least one of the Claims 3 to 10 characterized in that on the plug (11) a connecting piece (18) with an inner channel (19) is arranged, which leads to the inflow opening (7) and the lid (17) has a central Axialdurchbruch (20), which from the connecting piece (18). Device (1) according to at least one of Claims 3 to 11 characterized in that the spring element (12) in a spring chamber (21) is arranged, which between the plug (11) and the lid (13) is present and the cover (13) has a plurality of drainage openings (22), which in a radial Outside area of the lid (13) are distributed substantially regularly distributed over the circumference and connect the spring chamber (21) with an external environment of the device (1) pneumatically and hydraulically.

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