DE102019108261A1 - Pressure switching device - Google Patents

Abstract

A pressure switching device (1) which is designed in such a way that a membrane (19) acted upon by a fluid under pressure in a pressure chamber (14) of a housing (2, 2a, 2b) against the force of a compression spring (28) when a a switch (6) which is operatively connected to a device plug, the device plug having electrical contacts (9, 10, 11, 12) accessible from outside the housing, is characterized in that an opening (3) of the housing (2, 2a, 2b) an inner body (13) is inserted, which has several functional elements (20, 21, 29, 30, 31) of the pressure switch (1), to which the compression spring (28) belongs.

Description

The present invention relates to a mechanical pressure switch device according to the preamble of claim 1.

Such a pressure switching device is from DE 10 2009 003 757 A1 known. This design of the pressure switching device has proven itself very well in practice, but a simpler design is desirable against the background of an optimized assembly process.

It is therefore the object of the invention to solve this problem.

The invention solves this problem with the subject matter of claim 1.

A pressure switching device is created in which a membrane acted upon by a fluid under pressure in a pressure chamber of a housing actuates a switch against the force of a compression spring when a presettable switching pressure is reached, which is in operative connection with a device plug, the device plug from the outside - in particular from outside the housing - has electrical contacts accessible, wherein an inner body is furthermore placed in an opening of the housing, which has several functional elements of the pressure switch, to which the compression spring belongs.

The inner body thus forms a base body for a mechanical pre-assembly assembly which is designed such that it behaves like an individual part in the assembled state and can therefore be inserted simply by being pushed into an opening in the housing.

As a result, this pre-assembly subassembly can be used independently of the assembly process of the pressure switch device - e.g. be completely preassembled synchronously in a parallel preassembly process and thereby advantageously reduces the assembly process of the pressure switching device.

It can be provided that the inner body consists of plastic or metal. It can also consist of another material. It is preferably made of a plastic so that it can be manufactured inexpensively.

It can also be provided that the housing is made of metal. It is very advantageous that this can be produced inexpensively in a die-casting process according to the invention.

The pre-assembly process of the inner body with the mechanical components of the pressure switching device can also take place in a single assembly direction. This is advantageous because it means that the location and the position of the inner body do not have to be changed during assembly. Furthermore, this advantageously results in a clearly defined assembly sequence of the components to be assembled.

It can be provided that the inner body has a basic geometry that corresponds to the opening of the housing. In addition, it can further be provided that the inner body is designed like a sleeve and itself has at least one opening to accommodate the functional element or elements.

One of the functional elements can be designed as an actuation which is inserted displaceably in the opening of the inner body and with a shoulder extends through a further opening in the inner body. As a result, an actuation of the switch is created in the housing in a structurally simple manner and without additional manufacturing effort and thus advantageously.

The actuation has on its outer circumference an actuating lug which is formed in one piece and which reaches through an opening in the inner body. The integrally molded actuating lug creates an actuating element that is not subject to tolerances in a structurally simple and therefore advantageous manner.

Another functional element can be designed as a diaphragm plate, which sits with preferably slight play in a corresponding recess of the inner body and engages with an integrally molded pin attachment in a corresponding opening of the actuation, whereby the diaphragm plate is displaceably guided during actuation and secured against tilting. The membrane plate advantageously forces the membrane into a deformation defined by the membrane plate, whereby a one-sided deformation, which includes the risk of tilting of the membrane, is advantageously excluded during the deformation of the membrane.

The compression spring, which is centered on the actuation by the centering shoulder, can be inserted into a cavity of the actuation. As a result, the compression spring is structurally simple and therefore guided and centered advantageously.

The compression spring is supported with an end facing away from the actuation on a further functional element, which is a slide, the slide being guided displaceably in the inner body and thus secured against rotation. The sliding piece makes it structurally simple and without additional manufacturing effort in the housing Slidable pressure piece secured against rotation created for the compression spring, whereby the preload of the compression spring can be changed.

The threaded spindle and the nut preferably have a left-hand thread. This is advantageous because clockwise rotation - the intuitive "pressure amplification direction" of the threaded spindle - turns the threaded spindle back relative to the diaphragm, i.e. the pressure switching device reacts to a higher pressure.

A cover can close the opening on the side of the housing facing away from the membrane and fix the inner body together with the built-in functional elements in the housing. As a result, the opening of the housing is sealed off from the environment and the inner body is closed in the same way and thus advantageously.

The lid can be mounted such that it - e.g. by caulking with the housing - an axially acting sealing force is generated on the O-rings, so that the O-rings develop their sealing effect. This creates a space-saving and inexpensive and therefore advantageous fastening of the cover and creates a permanent sealing effect for the O-ring.

An assembly aid in the form of a form-fitting connection is provided for positioning the device plug relative to the inner body. Thanks to the assembly aid, the distance between a switching contact of the switch and the actuating lug of the actuation can be precisely maintained. This eliminates possible assembly inaccuracies when positioning the connector base and thus the device plug relative to the inner body, so that tolerances of the switching position of the pressure switch device - and thus the switching accuracy of the pressure switch device 1- are advantageously limited to a small amount.

The form-fit connection can be designed in the form of a tongue and groove connection. This creates a structurally simple and space-saving form-fit connection.

It can also be provided that the device plug is placed in and / or on a preferably lateral receiving opening of the housing.

Further advantageous embodiments of the invention are the subject of the subclaims.

• 1: eine räumliche Explosionsdarstellung einer erfindungsgemäßen Druckschaltvorrichtung;
• 2a: eine Vorderansicht der montierten Druckschaltvorrichtung aus 1;
• 2b: eine Draufsicht im Schnitt der montierten Druckschaltvorrichtung aus 2a;
• 2c: eine Rückansicht im Schnitt der Druckschaltvorrichtung aus 2a
• 2d: eine Ausschnittsvergrößerung der Druckschaltvorrichtung aus 2b bzw. 2c;
• 2e: eine Rückansicht im Schnitt der Druckschaltvorrichtung nach 1 mit einer Ausführungsvariante des Gehäuses.

Further advantages, features and details of the invention emerge from the following description, in which several exemplary embodiments of the invention are explained in more detail with reference to the accompanying figures. The invention is not restricted to this, but also does not include configurations that fall under the claims in the figures and in particular also equivalents of the exemplary embodiments. The person skilled in the art will expediently also consider the features disclosed in combination in the figures, the description and the claims individually and combine them into meaningful further combinations. Show it:

• 1 : a three-dimensional exploded view of a pressure switch device according to the invention;
• 2a : a front view of the assembled pressure switch device 1 ;
• 2 B : a plan view in section of the assembled pressure switch device 2a ;
• 2c : a rear view in section of the pressure switch device 2a
• 2d : an enlarged section of the pressure switch device 2 B or. 2c ;
• 2e : a rear view in section of the pressure switch device according to 1 with a variant of the housing.

1 shows a pressure switch device 1 in a spatial exploded view.

The pressure switch device 1 has a housing 2 on. This case 2 can be made from a pressure-resistant material in a primary molding process. It is preferably made of a metal. The housing is particularly preferred 2 made of an aluminum or zinc alloy. In particular, it can be produced in an inexpensive die-casting process.

The case 2 can have a cuboid and preferably rather elongated basic geometry, but this is advantageous but not mandatory.

The case 2 can be implemented in different, in particular two preferred, embodiments.

A preferred embodiment of the housing 2 is a "pipe variant" 2a, which can be recognized by an internal thread. It is used, for example, when the pressure switching device 1 is installed in a pressure line or in a pressure hose.

Another preferred embodiment of the housing 2 is the so-called "Board variant" 2b (see 1 and 2e) , which can be recognized by one or more - here two holes through which the housing 2 or the pressure switch device 1 can be attached to another component.

The case 2 furthermore has a preferably cylindrical opening 3 which is arranged here symmetrically to the lateral surfaces of the cuboid basic geometry and one of the end faces of the housing 2 breaks through.

The case 2 can also have a second opening, a receiving opening 4th , which are perpendicular and symmetrical to the first opening 3 in the case 2 can be arranged and a lateral surface 5 of the housing 2 can break through. Also this receiving opening 4th can be cylindrical.

The receiving opening 4th takes a switch when mounted 6th on. This can be designed as a sub-miniature switch. Furthermore, the jacket surface 5 of the housing 2 in the area of the receiving opening 4th a flange face 7th form on which a connector socket 8th with externally accessible electrical contacts 9 , 10 , 11 , 12 as well as a seal with screws and attached to it (see also 2 B , 2c as 2e) . A in the assembled state of the pressure switch device 1 between the housing 2 and the connector base 8th forming gap is sealed, here sealed with an O-ring.

The desk 6th is in the assembled state of the pressure switch 1 in electrical operative connection with the contacts 9 , 10 , 11 , 12 . In this respect, the connector form 8th , The contacts 9 , 10 , 11 , 12 as well as the seal and the screws from a preassembled device plug through which, for example, a switching pulse from the switch 6th out of the case 2 can be led to the outside or with which, for example, a circuit can also be interrupted or closed directly. This sits here at the receiving opening 4th .

The pressure switch device 1 also has an inner body 13 on, in the assembled state of the pressure switch 1 a plurality of mechanical components of the pressure switch device 1 records. In the inner body 13 are therefore functional elements of the pressure switching device 1 assembled. These are preferably several or all of the functional elements that are required for the mechanical functions of the pressure switching device 1 to enable (see also 2 B and 2c ). The inner body 13 has one with the opening 3 of the housing 2 Corresponding, here essentially cylindrical, basic geometry.

The inner body 13 thus forms a base body for a mechanical pre-assembly assembly which is designed in such a way that it behaves like an individual part in the assembled state and therefore simply by being pushed into the housing 2 can be used.

As a result, the pre-assembly assembly can be independent of the assembly process of the pressure switching device 1 -also, for example, time-synchronously in a pre-assembly process running in parallel, are completely pre-assembled and thereby advantageously reduces the cycle time of the assembly process of the pressure switching device 1 .

The inner body 13 is preferably made of a plastic material. The inner body is particularly preferred 13 made of a thermoplastic material in an injection molding process. It preferably has an essentially sleeve-like basic geometry, with a central opening penetrating it longitudinally 22nd .

In 2a is the pressure switch device 1 shown fully assembled. The contacts are clearly visible 9 , 10 , 11, 12, the connector 8th as well as the housing 2 that is shown here in the "pipe variant".

In 2 B and 2c is the pressure switch device 1 each shown in full section. The case 2 has next to the cylinder-shaped opening 3 one coaxial with the opening 3 arranged pressure chamber 14th on that is the opening 3 connects. To the pressure chamber 14th a connecting hole closes 15th that leads to a threaded hole 16 expanded. The connecting hole 15th as well as the threaded hole 16 are also coaxial with the opening 3 arranged.

The case 2 points through the opening arranged one behind the other 3 , the pressure chamber 14th , the connecting hole 15th as well as the threaded hole 16 (a housing cavity that goes from face to face). The threaded hole 16 is intended to accommodate a screw connection through which a pressure line or a pressure hose to the pressure switch device 1 can be connected.

Through the inner body 13 or the one with the inner body 13 The pre-assembly assembly formed as a central component can be the continuous housing cavity of the housing 2 be kept geometrically simple, since breakouts, inner shoulders or undercuts are not required, as they are from the inner body 13 are formed.

The housing cavity can therefore - except for the production of the internal thread of the threaded hole 16 - are produced completely, preferably by primary molding (particularly preferably by a die-casting process). As a result, a complex machining process for the housing cavity can advantageously be dispensed with.

The case 2 forms between the opening 3 and the pressure chamber 14th one shoulder off, their edges to the pressure chamber 14th are rounded with a radius. The shoulder has an annular groove 17th on which an O-ring 18th intervenes. On the O-ring 18th a membrane is supported 19th off that so the opening 3 closes on its side facing the pressure chamber. The membrane 19th is preferably made from a plastic material, particularly preferably from a thermoset.

The membrane 19th is controlled by a functional element of the pressure switch 1 in the form of a membrane plate 20th supported in the axial direction. The membrane plate 20th sits with slight play in a corresponding recess in the inner body 13 and engages with an integrally formed pin attachment in a corresponding opening of a further functional element, here as an actuation 21st is executed, a, whereby the diaphragm plate 20th in operation 21st is slidably guided and secured against tilting. The membrane plate 20th is preferably made of a plastic material.

The functional element actuation 21st can in the central opening 22nd of the inner body 13 Be inserted displaceably and have an essentially thimble-like basic geometry. The operation 21st takes action with one approach 23 an opening of the inner body 13 . The operation 21st furthermore has an actuating lug formed in one piece on its outer circumference 24 on. The actuation flag 24 a breakthrough takes hold 25th of the inner body 13 . The actuation flag 24 can thereby during a switching process of the pressure switching device 1 the switch 6th actuate.

The functional element actuation 21st still has a bottom here 26th on, which has the opening into which the pin attachment of the diaphragm plate 20th intervenes. The floor 26th points in the direction of the open end of the actuation 21st a centering approach. In a cavity 27 the thimble-like operation 21st is a compression spring 28 used by the centering on the actuation 21st is centered. The compression spring 28 acts via the actuation 21st and over the membrane plate 20th on the membrane 19th and exerted on the fluid pressurized membrane 19th a counterforce. The operation 21st is preferably made of a plastic material, preferably a thermoplastic.

The functional element compression spring 28 can be wound from a spring steel wire. The compression spring 28 supports itself with one of the actuation 21st remote end on a wide functional element that acts as a slider 29 is executed. The slider 29 is in the inner body 13 Slidably guided and thus secured against twisting. In the slider 29 is another functional element, here in the form of a nut 30th -which is designed here as a hexagon nut- used positively with regard to rotatability. The slider 29 is preferably made of a plastic material.

The compression spring 28 can have a relatively great length and a relatively small diameter. This results in a lower spring stiffness compared to the prior art. This advantageously enables a finely graduated adjustability of the preload of the compression spring 28 .

In the mother 30th is another functional element in the form of a threaded spindle 31 screwed in. The threaded spindle 31 has a head 32 on. The head 32 has a torque driving contour, such as a hexagon socket, so that the threaded spindle 31 can be set in a rotary motion with a suitable tool.

The threaded spindle 31 and the mother 30th preferably have a left-hand thread. This is advantageous because by turning the threaded spindle clockwise 31 turning back the threaded spindle 31 relative to the membrane 19th is achieved, ie the pressure switch device 1 thereby reacts to higher pressure. The threaded spindle 31 engages with a free end in an inner diameter of the compression spring 28 one.

The head 32 the threaded spindle 31 rests on an inner shoulder 33 of the inner body 13 starting that by a depression 34 is formed. In the depression 34 is an O-ring 35 arranged of the opening 22nd of the inner body 13 seals.

In 2c is also a depression 38 recognizable. The depression 38 can be expanded to a hole leading into the pressure chamber 14th flows out (see also 2e) . The hole serves as an alternative to the threaded hole 16 if the connection to a pressure line or a pressure hose is to be made transversely to the housing cavity or if this has to be done for reasons of space.

There is also an assembly aid for the exact positioning of the connector base 8th relative to the inner body 13 in the form of a form-fit connection in the manner of a groove 39 and feather 40 - Detect connection. The assembly aid can be used to determine the distance between a switching contact of the switch 6th and the actuation flag 24 of actuation 21st are strictly adhered to. This eliminates possible assembly inaccuracies when positioning the connector base 8th and thus the device plug relative to the inner body 13 eliminated so that tolerances of the switching position of the pressure switch device 1 - and thus the switching accuracy of the pressure switching device 1- are advantageously limited to a small amount.

In 2d is shown that the inner body 13 with one shoulder 36 on a corresponding inner contour of the opening 3 of the housing 2 is applied. One lid 37 , which is preferably made of a metallic material, closes the opening 3 on the side facing away from the membrane and fixes the inner body 13 including built-in parts 20th , 21st , 28 , 30th , 31 , 35 , 37 in the housing 2 . The lid 37 created by caulking with the housing 2 an axially acting sealing force on the O-rings 35 , 17th so that the o-rings 35 , 17th develop their sealing effect. The threaded spindle is also supported 28 on the lid 37 off so that the lid 37 an abutment for the threaded spindle 28 forms.

In the context of the present invention, the term “caulking” can be understood to mean the production of a non-positive and positive connection between two individual workpieces by means of a forming process. This deformation of the edge area of at least one of the parts takes place in such a way that the workpieces are permanently connected to one another.

The pre-assembly process of the inner body 13 with the mechanical components of the pressure switch 1 can be done in a single assembly direction. This is advantageous because it means that the location and the position of the inner body do not have to be changed during assembly. Furthermore, this advantageously results in a clearly defined assembly sequence of the components to be assembled 20th , 21st , 28 , 30th , 31 , 35 , 37 .

In 2e is the case 2 shown in the "panel variant" 2b. In contrast to the "pipe variant" in 2c is the depression here 38 been drilled to a hole in the pressure chamber 14th flows out. This allows the pressure switch 1 with a housing 2 in the "panel variant" 2b, attach it to plate-like components. These plate-like components can also be designed, for example, as valve blocks or pressure fluid distributors - also called manifolds ". The pressure switch can also be attached to it with screws, for example, through the two holes. An O-ring is used for sealing. The threaded hole 16 can be closed with a so-called blind plug (not shown here) if necessary.

The membrane 19th is designed in such a way that it deforms with increasing pressure. This deformation acts on the diaphragm plate 20th showing the deformation movement of the membrane 19th on the actuation 21st forwards. Via the actuation flag 22nd this movement becomes the switch 6th actuated.

One via the pressure switch device 1 Switched electrical device can thus switch off, for example, at a defined pressure of the fluid. The membrane 19th is about the compression spring 28 applied with a counter pressure. When the pressure in the fluid drops, the membrane deforms 19th back and the switch 6th closes (pump or compressor switches on). The compression spring 28 is preloaded by the threaded spindle 31 adjustable, with which the switch-on and switch-off pressure can be set. In most cases, the difference between switch-on and switch-off pressure (the hysteresis) remains constant.

List of reference symbols

1

Pressure switching device

2, 2a, 2b

casing

3

opening

4th

opening

5

Outer surface

6

counter

7th

Flange surface

8th

Connector base

9, 10, 11, 12

Contact

13

Inner body

14th

Pressure chamber

15th

Connecting hole

16

Threaded hole

17th

Ring groove

18th

O-ring

19th

membrane

20th

Membrane plate

21st

activity

22nd

opening

23

approach

24

Actuation flag

25th

breakthrough

26th

ground

27

cavity

28

Compression spring

29

Slider

30th

mother

31

Threaded spindle

32

head

33

Internal switch

34

Depression

35

O-ring

36

shoulder

37

cover

38

Depression

39

Groove

40

feather

QUOTES INCLUDED IN THE DESCRIPTION

This list of the documents listed by the applicant was 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.

Patent literature cited

• DE 102009003757 A1 [0002]

Claims (25)

Pressure switching device (1) which is designed in such a way that a membrane (19) acted upon by a fluid under pressure in a pressure chamber (14) of a housing (2, 2a, 2b) counteracts the force of a compression spring (28) when a presettable Switching pressure actuates a switch (6) which is in operative connection with a device plug, the device plug having electrical contacts (9, 10, 11, 12) accessible from outside the housing, characterized in that an opening (3) in the housing ( 2, 2a, 2b) an inner body (13) is set, which has several functional elements (20, 21, 29, 30, 31) of the pressure switch (1), to which the compression spring (28) belongs. Pressure switch device (1) after Claim 1 , characterized in that the inner body (13) forms a base body of a preassembly assembly, which is designed such that it behaves like an individual part when the functional elements are assembled, which can be inserted by being pushed into an opening in the housing. Pressure switch device (1) after Claim 1 or 2 , characterized in that the inner body (13) consists of plastic or metal. Pressure switch device (1) after Claim 3 , characterized in that the housing is made of metal. Pressure switch device (1) after Claim 4 , characterized in that the housing is manufactured in a die-casting process. Pressure switching device (1) according to one of the preceding claims, characterized in that the opening (3) breaks through an end face of the housing 2. Pressure switching device (1) according to one of the preceding claims, characterized in that the inner body (13) has a basic geometry corresponding to the opening (3) of the housing. Pressure switching device (1) according to one of the preceding claims, characterized in that the inner body (13) is designed like a sleeve and itself has an opening. Pressure switch device (1) according to one of the preceding claims, characterized in that one of the functional elements is an actuator (21) which is inserted displaceably into the opening (22) of the inner body (13) and an opening of the inner body with a shoulder (23) (13) takes action. Pressure switch device (1) after Claim 9 , characterized in that the actuator (21) has on its outer circumference an integrally formed actuating lug (24) which extends through an opening (25) in the inner body (13). Pressure switch device (1) according to one of the preceding claims, characterized in that one of the functional elements is a diaphragm plate (20) which sits in a corresponding recess in the inner body (13) and with an integrally molded pin attachment into a corresponding opening in the actuation (21) engages, whereby the diaphragm plate (20) is guided displaceably in the actuation (21) and secured against tilting. Pressure switching device (1) according to one of the preceding claims, characterized in that the compression spring (28) is inserted into a cavity (27) of the actuator (21) and is centered by the centering shoulder on the actuator (21). Pressure switch device (1) after Claim 12 , characterized in that the compression spring (28) is supported with an end facing away from the actuation (21) on a further functional element, which is a slider (29), the slider (29) being guided and displaceable in the inner body (13) is thereby secured against twisting. Pressure switch device (1) after Claim 13 , characterized in that a further functional element, which is a nut (30), is inserted positively in relation to rotatability in the slider (29). Pressure switch device (1) after Claim 14 , characterized in that a further functional element, which is a threaded spindle (31), is screwed into the nut (30), the threaded spindle (31) having a head (32) which has a torque entrainment contour, so that the threaded spindle ( 31) can be set in rotation with a suitable tool. Pressure switching device (1) according to one of the Claims 14 or 15th , characterized in that the threaded spindle (31) and the nut (30) preferably have a left-hand thread. Pressure switching device (1) according to one of the Claim 16 , characterized in that the head (32) of the threaded spindle (31) is supported on an inner shoulder (33) of the inner body (13) which is formed by a depression (34). Pressure switching device (1) according to one of the preceding claims, characterized in that an O-ring (35) is located in the depression (34) is arranged, which seals the opening (22) of the inner body (13). Pressure switching device (1) according to one of the preceding claims, characterized in that the inner body (13) rests with a shoulder (36) on a corresponding inner contour of the opening (3) of the housing (2). Pressure switch device (1) after Claim 19 , characterized in that a cover (37) closes the opening (3) on the side of the housing (2) facing away from the membrane and the inner body (13) together with built-in functional elements (20, 21, 28, 30, 31) in the housing (2) fixed. Pressure switch device (1) after Claim 20 , characterized in that the cover (37) generates an axially acting sealing force on the O-rings (35, 17) by caulking with the housing (2) so that the O-rings (35, 17) develop their sealing effect. Pressure switching device (1) according to one of the preceding claims, characterized in that the threaded spindle (28) is supported on the cover (37) so that the cover (37) forms an abutment for the threaded spindle (28). Pressure switching device (1) according to one of the preceding claims, characterized in that an assembly aid in the form of a form-fit connection is provided for positioning the device plug (8, 9, 10, 11, 12) relative to the inner body (13). Pressure switch device (1) after Claim 23 , characterized in that the positive connection is designed in the form of a groove (39) and tongue (40) connection. Pressure switching device (1) according to one of the preceding claims, characterized in that the device plug is placed in and / or on a receiving opening (4) of the housing (2, 2a, 2b), in particular in and / or on a lateral receiving opening (4 ) of the housing (2, 2a, 2b) is set.

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