DE102014209277A1 - Anti-pendulum valve for a hydraulic rotary drive - Google Patents

Abstract

The invention relates to a hydraulic valve (10) having a fluid flow path (12) extending between a first and a second valve port (21; 22), the fluid flow path (12) being between a first and a second path section (13; 14). partially limited by a relative to a longitudinal direction (11) movable spool (40) having in the longitudinal direction (11) successively a first, a second, a third, a fourth and a fifth switching position (51-55), wherein at least one spring (15; 16) is provided, which is clamped against the spool (40) so that it moves in the direction of the third switching position (53), wherein the spool (40) is acted upon by a pressure in the first path portion (13) in that it moves in the direction of the first switching position (51), being acted on by a pressure in the second path section (14) in such a way that it turns in the direction of the fifth switching position (55) egt, wherein the spool (40) is formed so that the fluid flow path (12) in the first and the fifth switching position (51; 55), the spool valve (40) being configured to define a constriction in the fluid flow path (12) in the second and fourth switching positions (52; 54). According to the invention, at least one groove (45) extending in the longitudinal direction is arranged on an outer peripheral surface (41) of the spool, the fluid flow path (12) being bounded by the spool (40) exclusively by the at least one groove (45).

Description

The invention relates to a hydraulic valve according to the preamble of claim 1.

Such a valve is out of the JP 58-39803 A known. It is preferably used in the rotary or rotary drive of a mobile work machine, in particular an excavator or a crane. It counteracts pendulum oscillations, which arise when pivoting the superstructure, if this is to be positioned very accurately. In particular, by pressure peaks are reduced, which arise in the pressurized fluid, which flows back and forth between the two motor terminals of a corresponding hydraulic motor.

The known hydraulic valve has a fluid flow path extending between first and second valve ports connected to first and second engine ports of a hydraulic motor. Further, a spool is provided which divides the fluid flow path into a first and a second path portion. The spool is movable with respect to a longitudinal direction, wherein it successively passes through a first, a second, a third, a fourth and a fifth switching position. He is biased by springs in the third switching position. From the pressure in the first path section, it is moved in the direction of the first switching position, wherein it is moved by the pressure in the second path section in the direction of the fifth switching position. In the first and fifth switching positions, the fluid flow path is blocked by the spool valve. These switch positions are when the hydraulic motor is rotated against an external load at approximately constant speed, said switching positions are assigned opposite directions of rotation. If the hydraulic motor is then braked, then the spool moves to the second or the fourth switching position, in which the spool forms a bottleneck in the fluid flow path. This allows pressurized fluid to be exchanged between the first and second motor ports, with pressure spikes being restricted by the bottleneck.

The advantage of the present invention is that the spool is made very small. Accordingly, the valve can be easily integrated into the housing of the hydraulic motor. Next, the valve is particularly inexpensive to produce.

According to the invention, it is proposed that at least one groove extending in the longitudinal direction is arranged on an outer circumferential surface of the control slide, wherein the fluid flow path on the part of the control slide is limited exclusively by the at least one groove. The in the JP 58-39803 A provided on the spool ring grooves are therefore no longer available. The valve connections may be mouth openings of a channel, which are arranged on the outside of a housing. An integrally formed valve may also be channels within a housing, which are not necessarily accessible from the outside. A longitudinally extending groove should in particular be understood to mean a groove whose length in the longitudinal direction is at least 5 times as great as its width transversely to the longitudinal direction.

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

It is preferred that the outer peripheral surface of the spool is formed circular cylindrical except for the at least one groove with a constant diameter, wherein it rests on a circular cylindrical longitudinal bore slidably. Preferably, the longitudinal bore is arranged in a housing of the valve, in or on which also the first and the second valve connection are provided.

It is preferred that the length of the at least one groove is greater than the length of the longitudinal bore. Thus, the at least one groove together with the longitudinal bore may form a portion of the fluid flow path which extends over the entire length of the longitudinal bore. The mentioned section forms the bottleneck mentioned above.

It is preferred that at least one groove group is provided, which has a plurality of mutually separate grooves, which extend with respect to the longitudinal direction over the same area on the spool, wherein all grooves of a group form parallel path sections in the fluid flow path. As a result, the desired flow resistance of the bottleneck can be set particularly accurately.

It is preferable that the grooves of a groove group are arranged uniformly distributed over the circumference of the outer peripheral surface of the spool. Thus, the bottleneck has substantially the same flow resistance regardless of the rotational position of the spool.

It is preferred that a single first groove group is provided, which is arranged such that the control slide in the third switching position by means of the first groove group defines a bottleneck in the fluid flow path. This is also in the third Switching a constriction in the fluid flow path available.

It is preferred that a second and a third groove group are provided, which are arranged offset to one another in the longitudinal direction such that the fluid flow path in the third switching position is blocked by the spool. Thus, the fluid flow path is blocked in the third switching position.

It is preferred that a first and a second spring chamber are provided, which are connected to each other via the longitudinal bore, wherein the first and the second spring chamber are formed so large that the spool, at least in the first switching position with a first end in the first spring chamber protrudes, wherein it protrudes at least in the fifth switching position with an opposite second end in the second spring space. The first and second spring chambers are preferably components of the fluid flow path. Preferably, in the second and fourth shift positions, at least one groove extends into the first and second spring chambers to form the bottleneck in the fluid flow path.

It is preferred that a first spring is provided, which is arranged in the first spring chamber, wherein it bears against the first end of the spool, wherein a second spring is provided, which is arranged in the second spring chamber, wherein it is arranged at the second end of the spool , Such a valve is particularly inexpensive and space-saving, since no separate receiving space for the first and the second spring must be provided, which bias the spool in the third switching position.

It is preferred that in each switching position at least one groove projects into at least one spring chamber. The corresponding control slide can be made particularly simple to provide the five switch positions.

It is preferred that a first throttle is arranged in the fluid flow path between the first valve port and the first spring chamber, wherein a second throttle is arranged in the fluid flow path between the second valve port and the second spring chamber. With the first and the second throttle movement vibrations of the spool are damped. The proposed arrangement of the first and the second throttle is particularly space and cost-saving.

It is preferred that the at least one groove transmits at a distance to both ends of the control slide, wherein in the first and / or in the fifth switching position one end of the groove is covered by the longitudinal bore. This ensures that the fluid flow path is blocked in the first and the fifth switching position.

It is preferred that a hydraulic motor is provided with a first and a second motor connection, wherein the first motor connection is connected to the first valve connection, wherein the second motor connection is connected to the second valve connection.

It is preferred that the spool is received in a housing of the hydraulic motor.

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.

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

1 a circuit diagram of a hydraulic drive system with a valve according to the invention;

2 a rough schematic longitudinal section of a valve according to a first embodiment of the invention; and

3 a rough schematic longitudinal section of a valve according to a second embodiment of the invention.

1 shows a circuit diagram of a hydraulic drive system 60 with a valve according to the invention 10 , The hydraulic drive system 60 is designed in the form of a closed hydraulic circuit, as well as an open hydraulic circuit can be provided with a tank. The first and the second motor connection 62 ; 63 a hydraulic engine 61 are via a first and a second connecting line 66 ; 67 with an associated pump 64 connected. The hydraulic motor 61 and the pump 64 are preferably designed as axial piston machines with adjustable displacement volume, so that the rotational speed and the direction of rotation of the hydraulic motor 61 can be adjusted by adjusting the corresponding displacement volumes. Alternatively, the hydraulic motor 61 and the pump 64 designed as radial piston machines. The hydraulic motor 61 has a leakage connection 65 on, on the leakage oil, which by unavoidable internal leakage from the pressure chambers of the hydraulic motor 61 escapes, for example, can be derived to a tank.

Between the first and the second connecting line 66 ; 67 the valve according to the invention is connected so that these via a fluid flow path 12 connected to each other, which is indicated by a dashed line. The junctions between the fluid flow path 12 and the first and second connection lines 66 ; 67 form the first and the second valve connection 21 ; 22 , The first and the second valve connection 21 ; 22 may be provided on the outside of a separate valve. However, it can also be a branching point within a duct system, in particular if the valve according to the invention 10 in the housing of the hydraulic motor 61 is integrated.

The fluid flow path 12 is from the valve 10 into a first and a second path section 13 ; 14 divided. The valve 10 has a first, a second, a third, a fourth and a fifth shift position 51 - 55 on, which in a movement of the corresponding spool (no. 40 in 2 and 3 ) are passed through one after the other. The valve 10 is through the first and the second spring 15 ; 16 biased in the middle, third switching position, in which the fluid flow path 12 locked depending on the embodiment of the invention (see. 1 and 3 ) or provided with a bottleneck (cf. 2 ). The valve 10 takes the third switch position 51 For example, then when the hydraulic motor 61 is not moved, being stopped by a brake (not shown).

Will now pressurized fluid, especially hydraulic oil, from the pump 64 over the first connection line 66 to the first motor connection 62 the hydraulic motor 61 promoted, so moves the valve 10 in the direction of the first switching position 51 because the in 1 left side of the valve 10 with the pressure in the first path section 13 acted 17 is. In the first switching position 51 is the fluid flow path 12 locked, leaving the valve 10 the hydraulic drive system 60 essentially not affected. It should be noted that the in 1 right side of the valve with the pressure in the second path section 14 acted 17 is.

When the displacement volumes of hydraulic motor 61 and / or pump 64 be adjusted in the sense of reducing the engine speed, so the pressure drops in the first connection line 66 , Due to the inertia of the hydraulic motor 61 moved (not shown) assembly increases simultaneously the pressure in the second connection line 67 at. This causes the valve 10 in the direction of the fifth shift position 55 is adjusted. The valve passes through 10 at least the second switching position 52 in which a bottleneck in the fluid flow path 10 is provided. Thus, pressurized fluid from the second connection line 67 in the first connection line 66 arrive, with the corresponding pressure difference is throttled by the bottleneck. Consequently, the above-mentioned pressure increase in the second connection line 67 reduced. In addition, the leads to the hydraulic motor 61 connected module does not oscillate.

In case of a reversal of the direction of rotation of the hydraulic motor 61 arise analogous to the ratios described above, wherein the roles of the first and the second connecting line, the first and fifth switching position and the second and the fourth switching position are respectively reversed.

Attention is still on the first and the second throttle 26 ; 27 that allow an excessively rapid change in pressures in the first and second path sections 13 ; 14 is avoided. As a result, vibration of the control spool are avoided.

2 shows a rough-schematic longitudinal section of a valve 10 according to a first embodiment of the invention. The valve 10 includes a housing 20 which is preferably the housing of the hydraulic motor. In the case 20 is a circular cylindrical longitudinal bore 23 provided, extending along a longitudinal direction 11 extends. At the first and the opposite second end 43 ; 44 the longitudinal bore 23 is a first or a second spring chamber 24 ; 25 in the case 20 provided in the radial direction larger than the longitudinal bore 23 is trained. The first spring chamber 24 is present with a separate closure part 28 tightly closed, which in the context of the present application as part of the housing 20 is looked at.

In the longitudinal bore 23 is a control valve 40 longitudinal 11 movably received, so that its first or second end 43 ; 44 in the associated first and second spring chamber 24 ; 25 protruding, with the movement of the spool 40 only ends when he is with his longitudinal end face 56 on the housing 20 abuts. Between the two longitudinal end surfaces 56 of the spool 40 and the housing 20 is in the first and the second spring space 24 ; 25 each a first or a second spring 15 ; 16 installed, which the spool in the in 2 bias shown third switching position. At the transition from the longitudinal bore 23 to one of the spring chambers 24 ; 25 is in each case an annular control edge 18 provided, which on the spool 40 is applied. The location of these control edges 18 relative to the grooves 45 determines in which switching position, the spool 40 located.

The first spring chamber 24 is over a first throttle 26 with the first valve connection 21 connected. The second spring chamber 25 is over a second throttle 27 with the second valve port 22 connected. The first and the second throttle 26 ; 27 are in 2 roughly schematically represented as bottleneck in the respective fluid channel. The fluid flow path 12 runs from the first valve connection 21 over the first throttle 26 in the first spring chamber 24 , From there continue over the grooves 45 in the spool 40 in the second spring chamber 25 and from there via the second throttle 27 to the second valve port 22 ,

The grooves 45 form a bottleneck in the fluid flow path, their flow resistance through the length 29 the longitudinal bore 23 and the cross-sectional area of the grooves 45 is determined.

At the in 2 illustrated first embodiment of the invention, the bottleneck is closed only in the first and the fifth switching position, in which the spool 40 with one of its two longitudinal end faces 56 on the housing 20 abuts. In this case, each one end of the grooves 45 from the longitudinal bore 23 covered so that the fluid flow path 12 is interrupted. It should be noted that the grooves 45 at both longitudinal ends 43 ; 44 in each case at a distance from the longitudinal end face 56 of the spool 40 end up. In the second, the third and the fourth switching position of the spool 40 the grooves form a bottleneck in the fluid flow path 12 , wherein in each case both groove ends not from the longitudinal bore 23 be covered.

It should be noted that the pressure in the first and in the second spring chamber 24 ; 25 on the associated longitudinal end face 56 of the spool 40 acts. As a result, the in 1 with the no. 17 characterized pressurization of the spool 40 realized with the pressure in the first and second path section.

It should also be noted that several grooves 45 are provided, which with respect to the longitudinal direction 11 over the same area of the spool 40 extend. The grooves mentioned 45 are uniformly distributed over the circumference of the outer peripheral surface 41 of the spool 40 arranged. The grooves 45 form a single first groove group 48 ,

3 shows a rough-schematic longitudinal section of a valve 10 according to a second embodiment of the invention. Except for the differences described below, the second embodiment is identical to the first embodiment 2 trained so that reference is made in this regard to the above statements. The same or corresponding parts are identified by the same reference numerals.

The second embodiment differs from the first embodiment only in the arrangement of the grooves 45 , In this case, in the second embodiment, a second and a third groove group 49 ; 50 provided, each having a plurality of identical grooves 45 which are evenly distributed over the circumference of the spool 40 are arranged. Within a group 49 ; 50 the grooves extend 45 with respect to the longitudinal direction 11 over the same area of the spool 40 , In the middle, third switching position, which in 3 is shown, the first end 43 the grooves 45 the second groove group 49 not from the longitudinal bore 23 covered, whereas the opposite second end 44 from the longitudinal bore 23 is covered. At the grooves 45 the third groove group 50 arise in the third switching position exactly the reverse conditions. The first end 43 the grooves 45 the third group 50 is from the longitudinal bore 23 covered, whereas the second end 44 the grooves 45 the third groove group 50 not from the longitudinal bore 23 is covered. This is in the third switching position one end of all grooves 45 from the longitudinal bore 23 covered so that the fluid flow path 12 locked in the third switching position.

In the second switching position both ends of the grooves 45 the second group 49 not from the longitudinal bore 23 covered so that they have a bottleneck in the fluid flow path 12 form. In the fourth switching position both ends of the grooves 45 the third groove group 50 not from the longitudinal bore 23 covered so that they have a bottleneck in the fluid flow path 12 form.

In the first and in the fifth switching position, in each case one end of all grooves 45 from the longitudinal bore 23 covered so that the fluid flow path 12 Is blocked.

As a result, the grooves 45 the second and the third groove group 49 ; 50 with respect to the longitudinal direction 11 staggered to each other.

LIST OF REFERENCE NUMBERS

10

hydraulic valve

11

longitudinal direction

12

Fluid flow path

13

first path section

14

second path section

15

first spring

16

second spring

17

pressurization

18

control edge

20

casing

21

first valve connection

22

second valve connection

23

longitudinal bore

24

first spring space

25

second spring space

26

first throttle

27

second throttle

28

closing part

29

Length of the longitudinal bore

40

spool

41

Outer circumferential surface

42

Diameter of the spool

43

first end

44

second end

45

groove

46

Length of the groove

47

Width of the groove

48

first groove group

49

second groove group

50

third groove group

51

first switching position

52

second switch position

53

third shift position

54

fourth shift position

55

fifth shift position

56

Longitudinal face

60

hydraulic drive system

61

hydraulic motor

62

first motor connection

63

second motor connection

64

pump

65

leakage connection

66

first connection line

67

second connection line

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

• JP 58-39803 A [0002, 0005]

Claims (14)

Hydraulic valve ( 10 ) with a fluid flow path ( 12 ) located between a first and a second valve port ( 21 ; 22 ), wherein the fluid flow path ( 12 ) between a first and a second path section ( 13 ; 14 ) partially from one with respect to a longitudinal direction ( 11 ) movable spool ( 40 ), which is longitudinally 11 ) successively a first, a second, a third, a fourth and a fifth switching position ( 51 - 55 ), wherein at least one spring ( 15 ; 16 ) is provided, which against the spool ( 40 ) is tense that this is in the direction of the third switching position ( 53 ), wherein the spool ( 40 ) of a pressure in the first path section ( 13 ) is acted upon in such a way that it moves in the direction of the first switching position ( 51 ), being dependent on a pressure in the second path section ( 14 ) is acted upon in such a way that it moves in the direction of the fifth switching position ( 55 ), wherein the spool ( 40 ) is formed so that the fluid flow path ( 12 ) in the first and the fifth switching position ( 51 ; 55 ) is locked, the spool ( 40 ) is designed so that in the second and the fourth switching position ( 52 ; 54 ) a bottleneck in the fluid flow path (FIG. 12 ), characterized in that on an outer peripheral surface ( 41 ) of the spool at least one longitudinally extending groove ( 45 ), wherein the fluid flow path ( 12 ) by the spool ( 40 ) exclusively by the at least one groove ( 45 ) is limited. Hydraulic valve according to claim 1, wherein the outer peripheral surface ( 41 ) of the spool ( 40 ) except for the at least one groove ( 45 ) circular cylindrical with a constant diameter ( 42 ) is formed, wherein they on a circular cylindrical longitudinal bore ( 23 ) slidably abuts. Hydraulic valve according to claim 2, wherein the length ( 46 ) of the at least one groove ( 45 ) greater than the length ( 29 ) of the longitudinal bore ( 23 ). Hydraulic valve according to one of the preceding claims, wherein at least one groove group ( 48 ; 49 ) is provided, which a plurality of mutually separate grooves ( 45 ), which with respect to the longitudinal direction ( 11 ) over the same area on the spool ( 40 ), all grooves ( 45 ) of a group ( 48 ; 49 ) parallel path sections in the fluid flow path (FIG. 12 ) form. Hydraulic valve according to claim 4, wherein the grooves ( 45 ) a groove group ( 48 ; 49 ) uniformly distributed over the circumference of the outer peripheral surface ( 41 ) of the spool ( 40 ) are arranged. Hydraulic valve according to claim 4 or 5, wherein a single first groove group ( 48 ) is provided, which is arranged such that the spool ( 40 ) in the third switching position ( 53 ) by means of the first groove group ( 48 ) a bottleneck in the fluid flow path ( 12 ) limited. Hydraulic valve according to claim 4 or 5, wherein a second and a third groove group ( 49 ; 50 ) are provided, which in the longitudinal direction ( 11 ) are arranged offset to one another such that the fluid flow path ( 12 ) in the third switching position ( 53 ) by the spool ( 40 ) is locked. Hydraulic valve according to one of claims 2 to 7, wherein a first and a second spring space ( 24 ; 25 ) are provided, which over the longitudinal bore ( 23 ), wherein the first and the second spring space ( 24 ; 25 ) are formed so large that the spool ( 40 ) at least in the first switching position ( 51 ) with a first end ( 43 ) in the first spring space ( 24 protrudes, wherein at least in the fifth switching position ( 55 ) with an opposite second end ( 44 ) in the second spring chamber ( 25 ) protrudes. Hydraulic valve according to claim 8, wherein a first spring ( 15 ) is provided, which in the first spring chamber ( 24 ), wherein at the first end ( 43 ) of the spool ( 40 ) is applied, wherein a second spring ( 16 ) is provided, which in the second spring chamber ( 25 ) is arranged at the second end ( 44 ) of the spool ( 40 ) is arranged. Hydraulic valve according to claim 8 or 9, wherein in each switching position ( 51 - 55 ) at least one groove ( 45 ) in at least one spring chamber ( 24 ; 25 ) protrudes into it. Hydraulic valve according to one of claims 8 to 10, wherein between the first valve port ( 21 ) and the first spring chamber ( 24 ) a first throttle ( 26 ) in the fluid flow path (FIG. 12 ), wherein between the second valve port ( 22 ) and the second spring space ( 25 ) a second throttle ( 27 ) in the fluid flow path (FIG. 12 ) is arranged. Hydraulic valve according to one of the preceding claims, wherein the at least one groove ( 45 ) at a distance from both ends ( 43 ; 44 ) of the spool ( 40 ), wherein in the first and / or in the fifth switching position ( 51 ; 55 ) one end of the groove ( 45 ) from the longitudinal bore ( 23 ) is covered. Hydraulic drive system ( 60 ) with a hydraulic valve ( 10 ) according to one of the preceding claims, wherein a hydraulic motor ( 61 ) with a first and a second motor connection ( 62 ; 63 ), the first motor terminal ( 62 ) with the first valve connection ( 21 ), the second motor terminal ( 63 ) with the second valve connection ( 22 ) connected is. A hydraulic drive system according to claim 13, wherein the spool ( 40 ) in a housing ( 20 ) of the hydraulic motor ( 60 ) is recorded.

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