DE102015213693A1 - Hydraulic valve assembly and method of mounting such a valve assembly - Google Patents

Abstract

Disclosed are a hydraulic valve assembly and a method for mounting a stroke limiter of a valve assembly in which a stroke is limited by a stop body on which a radial shoulder, preferably an end face of a recess, the set screw runs.

Description

The invention relates to a hydraulic valve assembly according to the preamble of claim 1 and a method for mounting a stroke limiter.

Such a hydraulic valve arrangement is for example from the DE 10 2010 048 068 A1 and the DE 10 2012 010 217 A1 known. This discloses a valve housing in which axially parallel a pressure regulating valve and a flow control valve of an axial piston pump are arranged. Each of these control valves has a valve body guided in a valve body, via which a pressure medium connection between a pressure applied to the pump pressure (system pressure) and a tank connection on the one hand and a control port on the other hand on or is zuusteuerbar, so that according to pressure medium flows to a pressure chamber of a control cylinder or the pressure space flows to the tank.

The valve bodies are acted upon in each case via a control spring in the direction of a rest position, in which the pressure chamber is connected to the tank and the pressure medium connection between the control port and the pressure system leading the pressure connection is shut off. The control behavior of the two control valves can be adjusted by changing the spring preload of the two control springs. For this purpose, each control spring on a screw indirectly or directly supported, so that the spring preload is changed by screwing or unscrewing the screw. The basic adjustment is made at the factory, whereby the set screw is clamped with a lock nut to determine the preset value.

The minimum spring preload is limited in these known solutions by a retaining ring, which is seen in the screwing of the screw behind this and the lock nut is inserted into the valve bore, so that unscrewing the screw is limited by this circlip. In this position, therefore, the control spring has its minimum bias. The spring preload can then be increased starting from this position by screwing the adjusting screw, wherein the end position is limited by running a threaded portion on the threaded outlet in the valve bore - in this position then the respective maximum control pressure is set. The threaded outlet thus acts in the sense of a stroke limitation.

The problem with this solution is that the end position determined by the thread outlet is relatively inaccurate, so that an exact adjustment of the maximum control pressure can not be performed with sufficient accuracy. In addition, it can come to the formation of chips when running the threaded portion of the screw on the threaded outlet, which can then damage the valve or affect its function.

In contrast, the invention has for its object to provide a hydraulic valve assembly and a method for mounting a stroke limiter of a valve assembly by the adjustment of the maximum or minimum control pressure is improved with little effort.

This object is achieved in terms of the hydraulic valve assembly by the features of claim 1 and in terms of the method by the features of the independent claim 10.

Advantageous developments of the invention are the subject of the dependent claims.

The hydraulic valve assembly according to the invention has a valve body, which is acted upon by a spring or spring arrangement in the direction of a basic position. The bias of the spring is adjustable by means of a set screw, wherein the travel is determined by a stroke limitation. This has a stroke in one direction limiting stop body, which is inserted into a screw at least partially receiving valve bore. At the screw a radial shoulder is formed, which can be brought to the stroke limiter in contact with the stop body. This solution according to the invention, the stroke of the screw for adjusting the bias is determined exactly by running the radial shoulder on the stopper body, so that, for example, a maximum control pressure is defined and adjustable with high accuracy.

Another advantage of the inventive positioning of the stopper body in the region of a radial shoulder of the screw is that the stopper body is no longer accessible from the outside and thus an accidental or deliberate change in the stop position and thus the maximum and / or minimum control pressure is not or only with difficulty , In addition, the valve bore can be made shorter, since - as in the above-described prior art - is no longer necessary to provide additional space for the insertion of the spring ring.

The stroke limiter can be used to limit the maximum or minimum spring preload.

According to the method according to the invention for mounting such a stroke limiter of a valve arrangement, a stop body is first positioned in the region of the radial shoulder of an adjusting screw. The adjusting screw is then screwed together with the stopper body in the valve bore of the valve assembly. In this valve bore, a receptacle for the stopper body is formed, so that after a predetermined Einschraubweg the screw, in which it comes into contact with a spring arrangement of the valve assembly, which is entrained by the radial shoulder stop body as a stroke limiter in this recording.

In simple words, the stopper body passes by screwing the screw into its operative position, so that no separate assembly step is required for positioning of this stopper body.

In a preferred embodiment of the invention, the radial shoulder is formed by a recess of the adjusting screw, wherein at least one end face of the recess for Hubbegrenzung in contact with the stop body can be brought.

In a particularly preferred solution, the recess is frontally limited by two end faces, which thus act as a stroke limiter for setting the maximum or minimum bias of the spring assembly.

In a variant of the invention, the stopper body can be designed as a spring ring or the like.

The preparation of the end surfaces forming recess is particularly simple if it is designed as an annular groove on the screw.

As a recess here also an area of the screw is considered, which is bounded by one or two annular collars or the like.

The assembly of the stopper body can be carried out without colliding with the thread of the valve bore when the diameter of the stopper body, in particular a spring ring, is smaller than the inside diameter of an internal thread of the valve bore.

The recess may be formed on a portion of the adjusting screw whose diameter is smaller than that of the set screw thread.

According to one embodiment of the invention, the stopper body is inserted in its mounting position in a receptacle of the valve bore and cantilevers in the radial direction in sections into the valve bore.

The hydraulic valve arrangement may for example be a control valve. Particularly preferably, this control valve can be designed as a pressure control or volume flow control valve.

Preferred embodiments of the invention are explained in more detail below with reference to schematic drawings. Show it:

1 a sectional view of a valve assembly in a first embodiment;

2 a variant of the embodiment according to 1 and

3 a flow diagram of a method for mounting a stroke limiter of a valve assembly according to the 1 and 2 ,

1 shows a longitudinal section of a control valve assembly 1 , which is used for example for pressure control and flow control of an axial piston pump. The type of flow control is also called LS control, wherein the pump is controlled so that the pump pressure by a predetermined pressure difference is higher than a pending on the control valve assembly control pressure, the usual way, the highest load pressure of all supplied by the pump with pressure medium hydraulic consumers is.

Such a control valve arrangement is for example in the DE 10 2012 010 217 A1 described, so that only the essential elements for understanding the invention will be explained and reference is otherwise made to the disclosure of the above-mentioned document.

The control valve assembly has a cartridge-shaped housing 2 in which a pressure control valve 4 and a flow control valve 6 are included. At the housing 2 are two end-side pressure ports P performed where, for example, the pump pressure is applied. The housing 2 Furthermore, there are two radial control connections A, which are, for example, in fluid communication with a pressure chamber of an actuating cylinder, via which a pivoting cradle of the axial piston pump is adjustable. Furthermore, a tank connection T and a connection LS, on which the highest load pressure of all consumers supplied by the pump are present, are formed on the housing. This LS connection is the flow control valve 6 assigned.

The flow control valve 6 and the pressure control valve 4 each have a valve body 8th . 10 standing in a valve hole 14 respectively. 16 is guided. Every valve body 8th . 10 is a control spring 18 . 20 assigned, via which the respective valve body 8th . 10 in the direction of a stop position against a stop pin 22 is biased. In this stop or home position is according to 1 the control port A of the flow control valve 6 connected to the tank port T and shut off the pressure medium connection to the pressure port P, so that, for example, the pressure chamber of an actuating cylinder of an axial piston machine is connected to the tank and then swings the pivoting cradle fully. The load pressure tapped via the connection LS acts against the pressure at the connection P on the valve body 8th so that it is shifted to its control position when the pressure at the pressure port P by the pressure equivalent of the associated control spring 20 greater than the load pressure at port LS.

In the illustration according to 1 is the pressure control valve 4 shown in a control position, in which the valve body 10 from the stop pin 22 is lifted off. In the non-illustrated contact position of the valve body 10 to the stop pin 22 is the pressure medium connection of the two interconnected control connections A to the frontal pressure port P of the pressure control valve 4 shut off. However, the two control ports A and the tank port T are when the valve body 8th of the flow control valve 6 at the stop pin 22 is applied, connected to each other, so that then via the flow control valve 6 and the pressure control valve 4 From the actuator cylinder pressure fluid can flow to the tank. When exceeding the over the control spring 18 set maximum pressure is the valve body 10 of the pressure control valve 4 - as in 1 shown displaced from its stop position to the right, so that the pressure medium connection between the two control terminals A and the tank port T controlled and the pressure medium connection from the pressure port P to the control port A is controlled, so that correspondingly pressure fluid flows into the pressure chamber of the actuating cylinder and the pivoting cradle in the direction of Zero position pivots back.

The rule feathers 18 . 20 are each on a set screw 24 . 26 supported in a radially expanded portion of the respective valve bore 16 . 14 is used. Each set screw has an external thread 28 . 30 with an internal thread 31 . 33 the valve bore is in mesh.

As shown in 1 is the external thread 28 . 30 each on a threaded collar 32 . 34 the adjusting screw 24 . 26 educated. On to a spring chamber for the control spring 18 respectively. 20 adjacent end section is the set screw 24 . 26 with an integrated spring plate 36 . 38 formed, on which the respective control spring 18 . 20 is supported.

Adjacent to the spring plate 36 . 38 (right in 1 ) is an O-ring seal 40 . 42 or another seal formed.

In the area between this O-ring seal 40 . 42 and the threaded collar 32 . 34 is in each case a recess formed as an annular groove 44 . 46 provided, in each case a spring washer 48 . 50 dips.

The function of these spring washers 48 . 50 is determined by the in 1 illustrated enlarged details X explained. In this detail X is visible part of the threaded collar 34 , with its external thread 28 with the internal thread 31 the extended part of the valve bore 16 in threaded engagement. As explained, the recess is 44 as an annular groove on the outer circumference of the adjusting screw 24 educated. The front side is this recess 44 by two radial shoulders forming end faces 52 . 54 limited. The diameter d of the adjusting screw 24 in the area of the face 54 is smaller than the diameter of the threaded collar 34 ,

Opposite is in the valve bore 16 a receiving groove 56 for the spring washer 48 educated. The depth of this recording groove 56 is chosen so that the spring washer 48 with a partial area in the recess 44 immersed and depending on the screwing of the screw 24 for limiting the stroke in contact with the face 52 or 54 can be brought.

In the illustration according to 1 the set screw is screwed out to set the minimum spring preload, leaving the slightly shorter end face 54 in contact with the spring washer 48 arrives. To adjust the maximum spring preload, the set screw 34 screwed in until they are with the face 52 on the spring ring 48 is applied. Both spring preloads are due to the defined system between spring ring 48 and the faces 52 . 54 exactly predetermined, so that the control range of the control valve is adjustable with great accuracy.

The recess 46 the adjusting screw 26 of the flow control valve 6 is in a corresponding manner with acting as abutment surfaces faces 58 . 60 educated.

For fixing the respective screw-in position of the set screws 24 . 26 is each a locknut 62 . 64 provided in the respective internal thread 31 . 33 the valve bore 14 . 16 is screwed in. As explained in the above-mentioned prior art, are on the screws 24 . 26 and at the lock nuts 62 . 64 respectively suitable recesses / projections for attachment of a tool formed by the orifice of the widened portion of the valve holes 14 . 16 can be set forth.

The assembly of these from the set screw 24 . 26 and the respective spring washers 48 . 50 formed stroke limitation is based 3 explained.

First, the spring ring 48 . 50 to the assigned set screw 24 . 26 set so that it is in the area of the respective recess 44 . 46 is arranged. The elastically deformable spring ring is characterized by the end faces 52 . 54 respectively. 58 . 60 secured against losing. The bottom of the annular groove-shaped recess 54 However, it is slightly spaced from the inner diameter of the respective spring ring 48 . 50 ,

In a further assembly step then the set screw 24 . 26 with the respective spring washer 48 . 50 to the valve bore 14 . 16 attached and screwed into this. By fitting and screwing the spring ring, according to the detail X a slightly larger diameter than the valve hole 14 . 16 in this area, biased radially inwardly, wherein the radial depth of the annular groove-shaped recess 44 is chosen so that this radial preload and the concomitant reduction of the spring ring diameter is made possible. In other words, the outer diameter of the spring ring is reduced when screwing the set screw 24 . 26 so that he is on the internal thread 31 . 33 the valve bore 14 . 16 can slide along until he is in the receiving groove 56 engages and is thus positionally secured with a residual prestress.

Something problematic with this solution is that the spring washer 48 slips along the thread, so that the thread and / or the spring ring can be damaged. This disadvantage is due to the 2 explained embodiment eliminated.

In 2 is just the one with the set screw 24 provided area of the pressure control valve 4 shown. The flow control valve 6 is executed in a similar manner. As in the previously explained embodiment, the screw is 24 with her threaded collar 34 in threaded engagement with the internal thread 31 the extended part of the valve bore 16 , The control spring 18 is on the spring plate 36 the adjusting screw 24 supported. The sealing of the spring chamber of the control spring 18 via the O-ring seal 40 ,

In the area between the threaded collar 34 and the O-ring seal 40 (or other suitable seal) is the recess 44 educated. This ringnutartige recess 44 is at a section 61 formed, whose diameter D is significantly less than the thread diameter of the threaded collar 34 , As in the previously described embodiment, the recess 44 through the two end faces 52 . 54 limited, in abutment with the spring washer 48 can be brought. This spring ring 48 has an outer diameter that is slightly smaller or at most the same size as the inside diameter of the internal thread 31 , In the mounting position, the spring washer snaps 48 in the housing-side receiving groove 56 one.

The essential difference from the embodiment described above is thus that the radial dimensions of the spring ring 56 and the circumferential recess 44 are chosen so that the spring washer 56 without appreciable collision with the internal thread 31 can be used.

Accordingly, according to the mounting scheme in 3 also in this embodiment, first of the spring ring 48 without bias in the region of the recess 44 to the set screw 24 and then into the valve bore 16 screwed in, wherein the spring ring when applied to the end face 52 without or at most with low friction through the internal thread 31 through into the area of the receiving groove 56 is guided and finally locks into this. Just as in the embodiment described above is then the maximum screw-in position (bias of the control spring 18 maximum) through the face 52 and the minimum screw-in position (preload of the control spring 18 minimal) by the emergence of the other end face 54 on the spring washer 48 certainly.

The stroke limitation of in 2 not shown flow control valve 6 is designed accordingly.

In the embodiments described above, a spring ring is provided as a stopper body; Of course, other suitable elements can be provided, which are designed so that they are inserted into a receiving groove 56 or the like engage / snap or can be used.

The stroke limitation described above serves both to determine the maximum and the minimum spring preload. Dismantling is very difficult, so that an accidental or arbitrary adjustment in deviation from the given stroke is difficult. Another advantage of the solution according to the invention is that the stroke limiter is integrated into the valve, can be mounted in a simple manner and also saves installation space due to its compact dimensions. Furthermore, this solution can be realized very inexpensively.

The Hubbegrenzung invention is of course not only on the application Limited control valves but can also be used in other types of valves.

As explained above, the stroke limitation can also be effected, for example, by cooperation of a radial shoulder formed on a radial collar and of the stop body, preferably of the spring ring.

Disclosed are a hydraulic valve assembly and a method for mounting a stroke limiter of a valve assembly in which a stroke is limited by a stop body on which a radial shoulder, preferably an end face of a recess, the set screw runs.

LIST OF REFERENCE NUMBERS

1

 valve assembly

2

 casing

4

 Pressure control valve

6

 Flow control valve

8th

 valve body

10

 valve body

14

 valve bore

16

 valve bore

18

 control spring

20

 control spring

22

 stop pin

24

 screw

26

 screw

28

 external thread

30

 external thread

31

 inner thread

32

 threaded collar

33

 inner thread

34

 threaded collar

36

 spring plate

38

 spring plate

40

 O-ring seal

42

 O-ring seal

44

 recess

46

 recess

48

 spring washer

50

 spring washer

52

 face

54

 face

56

 receiving groove

58

 face

60

 face

61

 Section of the adjusting screw

62

 locknut

64

 locknut

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

• DE 102010048068 A1 [0002]
• DE 102012010217 A1 [0002, 0028]

Claims (11)

Hydraulic valve arrangement with a valve body ( 8th . 10 ), which is acted upon by a spring whose bias by means of a set screw ( 24 . 26 ) is adjustable, wherein the travel is limited by a stroke limiter, which has a stroke limiting the travel in one direction, in a the adjusting screw ( 24 . 26 ) at least partially receiving valve bore ( 14 . 16 ), characterized in that on the adjusting screw ( 24 . 36 ) is formed a radial shoulder which can be brought to the stroke limiter in contact with the stop body. Valve arrangement according to claim 1, wherein the radial shoulder through a recess ( 44 . 46 ) of the adjusting screw ( 24 . 26 ) is formed, into which the stop body dips, wherein at least one end face ( 52 . 54 ) of the recess ( 44 . 46 ) can be brought to the stroke limiter in contact with the stop body. Valve arrangement according to claim 2, wherein the recess ( 44 . 46 ) frontally by two end faces ( 52 . 54 ) is limited, which act as a stroke limiter for setting the maximum or minimum spring preload. Valve arrangement according to claim one of the preceding claims, wherein the stopper body a spring washer ( 48 . 50 ). Valve arrangement according to one of the preceding claims 2 to 4, wherein the recess ( 44 . 46 ) is an annular groove. Valve arrangement according to one of the preceding claims, wherein the diameter of the stop body, in particular a spring ring ( 48 . 50 ), smaller than the inside width of one with the adjusting screw ( 24 . 26 ) in thread-engaging internal thread ( 31 . 33 ). Valve arrangement according to one of the claims 2 to 6, wherein the recess ( 44 . 46 ) in a section ( 61 ) of the adjusting screw ( 24 . 26 ) is formed, whose diameter (D) is smaller than the slight width of an internal thread ( 31 ) of the valve bore ( 14 . 16 ). Valve arrangement according to one of the preceding claims, wherein the stop body, in particular a spring ring ( 48 . 50 ), in a receptacle of the valve bore ( 14 . 16 ) is inserted and radially into the valve bore ( 14 . 16 ) protrudes into it.  Valve arrangement according to one of the preceding claims, wherein the valve arrangement is a control valve, in particular a pressure control or flow control valve. Method for mounting a stroke limiter of a valve arrangement, in particular according to one of the preceding claims, wherein the valve arrangement comprises a valve in a valve bore ( 14 . 16 ) guided valve body ( 8th . 10 ), which is acted upon by a spring arrangement whose bias by means of a set screw ( 24 . 26 ) is adjustable, wherein the stroke of the adjusting screw ( 24 . 26 ) is limited by a stroke limitation, comprising the steps of: - positioning a stopper body in the region of a radial shoulder, preferably an end face of a recess ( 44 . 46 ), the adjusting screw ( 24 . 26 ), - fitting the adjusting screw ( 24 . 26 ) to a valve bore ( 14 . 16 ) of the valve assembly in which a receptacle for the stopper body is formed and - screwing the set screw ( 24 . 26 ) at least until it comes into contact with the spring arrangement and the stop body taken by a radial shoulder is positioned in the receptacle. Method according to claim 10, wherein the stopper body as a spring ring ( 48 . 50 ) is formed and is brought by screwing in a locking position in the receptacle.

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