DE102017212450A1 - Proportional pressure reducing valve with seat valve - Google Patents

Abstract

The invention relates to a proportional pressure reducing valve (10) having a housing (20) in which a control slide (40) is received in a linearly movable manner with respect to a longitudinal axis (13), the housing (20) having a first, a second and a third connection (21; According to the invention, the control spool (40) has an annular groove (43), forming together with the housing (20) a continuously adjustable second diaphragm (12), the first and second diaphragms (11, 12 ) are continuously adjustable in opposite directions by movement of the control slide (40), wherein the first connection (21) is fluidically connectable to the annular groove (43) via a seat valve (60) and further via the first diaphragm (11), wherein the second connection ( 22) is fluidically connectable to the annular groove (43) via the second orifice (12), wherein the third connection (23) is directly fluidly connected to the annular groove (43), wherein the seated valve (60) has a valve seat (61) on the housing (20) and a vent ilkörper (62), wherein the valve body (62) from the valve seat (61) is liftable by the spool (40) is moved in the direction of enlargement of the first panel (11).

Description

The invention relates to a proportional pressure reducing valve according to the preamble of claim 1.

From the catalog, which was available on 23.05.2017 under the Internet address http://www.boschrexroth.com/various/utilities/mediadirectory/download/ index.jsp? Object_nr = RD64656, a Proportionaldruckreduzierventil is known. This is designed in slider construction. As a result, leaks may occur which, for example, cause the pressure regulated at the third port to slowly drop after the valve has been de-energized.

It is known to avoid leakage through the use of poppet valves. From the DE 10 2014 204 070 A1 For example, a valve is known in which adjustable panels are combined in slide construction with an adjustable aperture in seat design.

An advantage of the present invention is that leaks at the third port are avoided or greatly reduced when the proportional pressure reducing valve is in its spring biased home position.

According to the independent claim it is proposed that the spool has an annular groove which forms a first and a second control edge, wherein the first control edge has a smaller diameter than the second control edge, wherein the first control edge forms a continuously adjustable first diaphragm together with the housing wherein the second control edge forms a continuously adjustable second diaphragm together with the housing, wherein the first and the second diaphragm are continuously adjustable in opposite directions by movement of the spool, wherein the first port via a seat valve and further via the first diaphragm fluidly connected to the annular groove is, wherein the second connection via the second diaphragm is fluidly connected to the annular groove, wherein the third port is fluidly connected directly to the annular groove, wherein the seat valve comprises a valve seat on the housing and a valve body, wherein the valve seat with the valve body closable i st, wherein the valve body is liftable from the valve seat by the spool is moved in the direction of enlargement of the first diaphragm, wherein a spring is provided, with which the spool is acted upon in the direction of a reduction of the first diaphragm. Preferably, an electromagnet is provided, which acts on the spool in the direction of enlargement of the first diaphragm. The spring and the electromagnet are preferably arranged at opposite ends of the control spool with respect to the longitudinal axis. The valve body is preferably formed separately from the spool, wherein it is at least conceivable to form the valve body in one piece with the spool. The proportional pressure reducing valve is preferably used with a pressurized fluid in the form of a liquid, the pressurized fluid most preferably being hydraulic oil.

In the dependent claims advantageous refinements and improvements of the invention are given.

It can be provided that in a closed state of the seat valve, the first panel is closed, wherein the second panel is open. This state is biased by the spring, so that it sets in the de-energized state of the electromagnet. In this state, the leakage path from the third port to the first port is fluid-tightly sealed.

It can be provided that the valve body is formed separately from the control slide, wherein it can be brought into contact contact with a longitudinal end of the control slide associated with the first control edge. This ensures a tight contact of the valve body with the spool valve. Next tilting of the spool is avoided. When the poppet valve is open, the valve body preferably contacts the spool. When the seat valve is closed, there is preferably a small clearance between the valve body and the spool.

It can be provided that the valve body has a conical projection which can be brought into contact contact with the control slide. As a result, a tilting mobility between the valve body and the spool is made possible, so that said risk of tilting is further minimized. The conical projection is preferably formed in a circular cone with respect to the longitudinal axis. He preferably engages in a conical recess in the spool. The conical recess is preferably formed in a circular cone shape with respect to the longitudinal axis.

It can be provided that the valve body is acted upon by the spring in the direction of the valve seat in such a way that the spring also acts on the control slide when the seat valve is open. On the use of a separate spring for the spool can be dispensed with. Furthermore, a gap-free system between valve body and spool is ensured when the seat valve is open.

It can be provided that the housing is fixedly connected to a pole tube, which at the second control edge associated longitudinal end the control spool is arranged, wherein the pole tube defines an armature space in which an armature is accommodated, which is movable in the direction of the longitudinal axis, wherein it is coupled in movement with the control slide, wherein the pole tube is surrounded by an electric coil. Thus, the pressure at the third connection can be adjusted by applying current to the electric coil. Instead of this electrical adjustment, a hydraulic adjustment may be provided, in which the control slide is acted upon by a control pressure, preferably on the side facing away from the spring side. The control pressure can be provided with an electrically adjustable pilot valve.

It can be provided that the spool has a first channel, via which the annular groove is fluidly connected to the armature space. Thus, a relatively high pressure acts in the armature space, so that it can be easily vented. Alternatively, it is conceivable that the armature space is fluidly connected to the first port via the first channel.

It can be provided that the housing is designed for receiving in a receiving bore, wherein it has a first, a second, a third and a fourth section, which are arranged in the order mentioned in the direction of the longitudinal axis side by side, wherein they each by sealing webs are delimited on the housing, wherein the first portion is disposed at a longitudinal end of the housing, wherein the first portion forms the first port, wherein the poppet valve is fluidly connected via the second portion with the first panel. As a result, the fluid connection between the seat valve and the first panel is produced in a particularly simple and cost-effective manner.

It can be provided that the third section forms the third connection, wherein the fourth section forms the second connection. As a result, leaks between the second and the third port are avoided.

It is understood that the features mentioned above and those yet to be explained below can be used not only in the particular combination indicated, but also in other combinations or in isolation, without departing from the scope of the present invention.

• 1 ein erfindungsgemäßes Proportionaldruckreduzierventil im Längsschnitt.

The invention will be explained in more detail below with reference to the accompanying drawings. It shows:

• 1 a proportional pressure reducing valve according to the invention in longitudinal section.

1 shows a proportional pressure reducing valve according to the invention 10 in longitudinal section. The Proportionaldruckreduzierventil is designed in the form of a cartridge valve, which for installation in a standardized receiving bore 14 in a parent assembly 15 is provided. At the parent assembly 15 For example, it is a valve block comprising a plurality of other valves. The receiving bore 14 is preferably formed as a stepped bore, wherein the various terminals 21 ; 22 ; 23 the proportional pressure reducing valve 10 each associated with a different diameter level.

The proportional pressure reducing valve 10 has a housing 20 , Which in this case two separate, firmly interconnected parts 20a ; 20b includes, wherein it may also be integrally formed. The housing 20 is present by means of a flange 20c at the parent assembly 15 attached, wherein it also by means of an external thread in an internal thread of the receiving bore 14 can be screwed. On the case 20 is a pole tube 91 attached, so that inside the composite of housing 20 and pole tube 91 a fluid-tight closed space results, in which an anchor 93 in the direction of a longitudinal axis 13 is movably recorded. The entire in 1 The arrangement shown is essentially rotationally symmetrical with respect to the longitudinal axis 13 educated. The pole tube 91 one is an electromagnet 90 forming electrical coil 94 surrounded, which in turn of a cup-shaped coil housing 96 is surrounded. The coil housing 96 is with a pole disk 97 closed, the gap free at the pole tube 91 and on the bobbin case 96 abuts, so that one except for the flow interruption section 95 closed magnetic circuit results, which the pole tube 91 , the housing part 20b , the coil housing 96 and the pole disk 97 includes. The said parts are preferably made of magnetically conductive material, in particular of steel. The flow interruption portion may be a wall thickness-reduced portion of the pole tube 91 act so that the local material gets into magnetic saturation when the electric coil 94 over the electrical connection 98 is supplied with electric current. But it is also conceivable that the pole tube 91 in the area of the river interruption section 95 made of a magnetically non-conductive material.

The anchor 93 is also made of magnetically conductive material. He is with holes 99 provided, which a fluid exchange between the anchor spaces 92 in the pole tube 91 allowed, which by the anchor 93 are separated from each other. This will change the movement of the anchor 93 not hindered by trapped pressurized fluid. In the in 1 illustrated basic position of the Proportionaldruckreduzierventils 10 becomes the anchor 93 from the spring 70 from the case 20 pressed away, so he at the closed end of the pole tube 91 is applied. In this position is the anchor 93 at a distance to the housing part 20b arranged so that the above-mentioned magnetic circuit does not have the anchor 93 closed is. Will the electric coil 94 energized, so acts on the armature 93 a magnetic force that these on the housing part 20b moved so that the magnetic circuit closes over the armature. This is the spring 70 which is on the opposite side of the spool 40 is arranged, compressed. The river break section 95 is in the region of that longitudinal end of the anchor 93 arranged, which the housing part 20b is facing.

The spool 40 is in the direction of the longitudinal axis 11 movable in the housing 20 added. He has a first channel 46 that is concentric with the longitudinal axis 13 is arranged and which is designed as a blind hole. In the first channel 46 is a separate circular cylindrical ram 49 pressed, which in touching contact with the anchor 93 stands, so that its magnetic force on the plunger 49 on the spool 40 is transmitted. On the opposite side is between the spool 40 and the spring 70 a separate valve body 62 built-in. In the in 1 illustrated basic position closes the valve body 62 a valve seat 61 on the housing 20 , being from the spring 70 fluid-tight against the valve seat 61 is pressed. The valve seat 61 points from the spool 40 away, being circular about the longitudinal axis 13 circumferential sealing edge is formed. The assigned sealing surface 63 on the valve body 62 is circular in shape with respect to the longitudinal axis 13 educated.

The valve body 62 has a conical extension on the front side 64 which is in a frontal conical recess 65 at the spool 40 intervenes. When the spool 40 by magnetic force on the spring 70 is moved to, there is a point-like contact between the valve body 62 and spool 40 , which allows a low tilting mobility between the known parts. In the in 1 illustrated basic position there is a small distance there, said parts can rest against each other with little force. In both cases, the sealing engagement is on the seat valve 60 not disturbed. The conical recess 65 is on a frontal extension 48 of the spool 40 arranged, whose diameter relative to the sealing first circular cylindrical portion 44 is reduced, so that there is a free space for the pressurized fluid.

End in the housing 20 is a separate support body 71 received, which is pot-shaped. The supporting body 71 is in the case 20 pressed so that he is firmly connected to this. At its bottom side is the support body 71 preferably with several longitudinal bores 72 provided, which allow fluid passage. The feather 70 , which is preferably formed as a helical spring is at the bottom of the support body 71 in the direction of the longitudinal axis 13 supported. At the valve body 62 it is held by a circular cylindrical pin.

The housing 20 has on its outer peripheral surface a first, a second, a third and a fourth section 24 ; 25 ; 26 ; 27 in the order given in the direction of the longitudinal axis 13 are arranged side by side, passing through sealing webs 28 are separated fluid-tight from each other. The sealing webs 28 are each provided with a sealing ring, which seals at the receiving bore 14 is applied. Every sealing bar 28 is another stage of the receiving bore 14 assigned, so that damage to the sealing rings when installing the Proportionaldruckreduzierventils 10 into the receiving hole 14 is avoided.

The outermost longitudinal end arranged first section 24 forms a first connection 21 which is fluidically connected to a pressure fluid sink, for example a tank. The fourth section 24 forms a second connection 22 fluidly connected to a source of pressurized fluid, such as a pump. The interposed third port 23 is from the third section 26 educated. The third connection 23 forms the output of the proportional pressure reducing valve 10 at which a pressure is applied, which is between the pressure at the first port 21 and the pressure at the second port 22 lies.

The spool 40 has an annular groove 43 which with their with respect to the longitudinal axis 13 opposite side walls a first and a second control edge 41 ; 42 forms. The ring groove 43 is over at least one radial bore 29 in the case 20 fluidic with the third port 23 connected, in such a way that in each position of the spool 40 in the ring groove 43 the pressure at the third port 23 is applied.

In the spool 40 can at least one radial bore 50 be provided, which is the annular groove 43 with the first channel 46 connects, so in the first channel 46 and in the pole tube 91 also the pressure at the third port 23 is applied, wherein a movement of the spool 40 is not hindered by trapped pressurized fluid. It is also conceivable that said spaces instead fluidly with the first port 21 are connected so that there is a low pressure.

The spring 70 facing first control edge 41 has a smaller diameter than the anchor 93 facing second control edge 42 , The proportional pressure reducing valve 10 it's so designed that the pressure on the third port 23 effectively acts on the appropriate area difference, so he puts one on the anchor 93 directed to directed hydraulic force.

The second control edge 42 is at least one more radial bore 29 in the case 20 assigned, so that is an adjustable second aperture 12 results. This is open in the basic position, whereby it diminishes, if the spool 40 on the spring 70 to be moved. The second connection 22 is about the second aperture 12 , continue over the ring groove 43 with the third connection 23 fluidically connectable. Adjacent to the second control edge 42 has the spool 40 one with respect to the longitudinal axis 13 circular cylindrical second section 45 , the fluid-tight on the housing 20 is applied.

The first control edge 41 is at least one more radial bore 29 in the case 20 assigned, so that is an adjustable first aperture 11 results. This is closed in the basic position, whereby it increases when the spool 40 on the spring 70 to be moved. Adjacent to the first control edge 41 has the spool 40 one with respect to the longitudinal axis 13 circular cylindrical first section 44 , the fluid-tight on the housing 20 is applied. The first and the second aperture 11 ; 12 are not in any position of the spool 40 open simultaneously, leaving a short circuit between the first and the second port 21 ; 22 is avoided. The second section 25 outside on the housing 20 is about the first aperture 11 , continue over the ring groove 43 with the third connection 23 fluidically connectable. Next is the second section 25 over another radial bore 29 in the case 20 , continue over the seat valve 60 with the first connection 21 connectable. Due to the above-described motion coupling between spool 40 and valve body 62 have the seat valve and the first panel 11 a similar opening behavior when the spool 40 is moved. The seat valve 60 causes the fluid flow path from the third to the first port 23 ; 21 is sealed fluid-tight. In this fluid flow path occur in the known Proportionaldruckreduzierventil the largest leaks due to the proportional pressure reducing valve according to the invention 10 be avoided.

LIST OF REFERENCE NUMBERS

10

proportional pressure

11

first aperture

12

second aperture

13

longitudinal axis

14

location hole

15

higher-level module

20

casing

20a

housing part

20b

housing part

20c

flange

21

first connection

22

second connection

23

third connection

24

first section

25

second part

26

third section

27

fourth section

28

sealing land

29

Radial bore in the housing

40

spool

41

first control edge

42

second control edge

43

ring groove

44

first circular cylindrical section

45

second circular cylindrical section

46

first channel

48

extension

49

tappet

50

radial bore

60

poppet valve

61

Valve seat on the housing

62

valve body

63

sealing surface

64

cone-shaped extension

65

conical recess on the spool

70

feather

71

Supporting body for spring (pot-like)

72

longitudinal bore

90

electromagnet

91

pole tube

92

armature space

93

anchor

94

electric coil

95

River interrupting section

96

coil housing

97

pole disk

98

electrical connection

99

Hole in the anchor

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 102014204070 A1 [0003]

Claims (9)

Proportional pressure reducing valve (10) having a housing (20) in which a control slide (40) is received in a linearly movable manner with respect to a longitudinal axis (13), wherein the housing (20) has a first, a second and a third connection (21; 22; 23) characterized in that the spool valve (40) has an annular groove (43) which forms a first and a second control edge (41; 42), the first control edge (41) having a smaller diameter than the second control edge (42). wherein the first control edge (41) together with the housing (20) forms a continuously adjustable first diaphragm (11), wherein the second control edge (42) together with the housing (20) forms a continuously adjustable second diaphragm (12) the first and the second aperture (11; 12) are continuously adjustable in opposite directions by movement of the control slide (40), the first connection (21) being fluidically connected to the annular groove via a seat valve (60) and further via the first aperture (11). 43) The second connection (22) can be fluidically connected to the annular groove (43) via the second diaphragm (12), wherein the third connector (23) is directly fluidically connected to the annular groove (43), wherein the seat valve (60 ) comprises a valve seat (61) on the housing (20) and a valve body (62), wherein the valve seat (61) with the valve body (62) is closable, wherein the valve body (62) from the valve seat (61) can be lifted by the Control slide (40) in the direction of enlargement of the first diaphragm (11) is moved, wherein a spring (70) is provided, with which the spool (40) in the direction of reduction of the first diaphragm (11) can be acted upon. Proportional pressure reducing valve after Claim 1 wherein, in a closed state of the poppet valve (60), the first orifice (11) is closed, the second orifice (12) being open. Proportionaldruckreduzierventil according to any one of the preceding claims, wherein the valve body (62) is formed separately from the spool (40), wherein it is engageable with one of the first control edge (41) associated longitudinal end of the spool (40) in touching contact. Proportional pressure reducing valve after Claim 3 wherein the valve body (62) has a conical extension (64) which can be brought into contact contact with the control slide (40). Proportional pressure reducing valve according to one of the preceding claims, wherein the valve body (62) by the spring (70) in the direction of the valve seat (61) is acted upon such that the spring (70) also acts on the spool (40) when the seat valve (60) is open. Proportional pressure reducing valve according to one of the preceding claims, wherein the housing (20) is fixedly connected to a pole tube (91), which at the second control edge (42) associated longitudinal end of the spool (40) is arranged, wherein the pole tube (91) an armature space (92), in which an armature (93) is received, which is movable in the direction of the longitudinal axis (13), wherein it is coupled to the control spool (40), wherein the pole tube (91) from an electrical coil (94) is surrounded. Proportional pressure reducing valve after Claim 6 wherein the spool (40) has a first channel (46) via which the annular groove (43) is fluidically connected to the armature space (92). A proportional pressure reducing valve according to any one of the preceding claims, wherein the housing (20) is adapted to be received in a receiving bore (14) having first, second, third and fourth portions (24; 25; 26; 27) in the order mentioned in the direction of the longitudinal axis (13) are arranged side by side, wherein they are each bounded by sealing webs (28) on the housing (20) from each other, wherein the first portion (24) is arranged at a longitudinal end of the housing (20), wherein the first portion (24) forms the first port (21), wherein the poppet valve (60) is fluidically connected to the first orifice (11) via the second portion (25). Proportional pressure reducing valve after Claim 8 wherein the third portion (26) forms the third terminal (23), the fourth portion (27) forming the second terminal (22).

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