AU656933B2 - Control valve - Google Patents

Description

CONTROL VALVE

The present invention relates to hydraulic control valves, in particular, for the manual control of hydraulic power machines such as double acting cylinders, reversible hydraulic motors and the like. The invention being particularly aimed at providing a single control valve which will enable the operation of more than one such hydraulic machine alternately or multiples of said hydraulic machinery selectably at a similar time. The invention will hereinafter be described in relation to the control valve being adapted to control hydraulic lift cylinders, however, it will be readily apparent that the invention is also applicable to controlling any other hydraulically powered machine. Conventionally, hydraulic speed and directional control valves have been designed as singular operative units such that they control one hydraulic cylinder, or simultaneously additional hydraulic cylinders. Such control valves have generally been not capable of selectively operating separate hydraulic cylinders, or selectably one or more but not all of the hydraulic cylinders simultaneously. To overcome this shortcoming, several means have been used in the prior art.

These include "stacking" of valves or by using cross-over linkages, and/or specific operator levers and linkage connections. When used in multiple connections there are several disagreeable factors involved such as, excessive horsepower needed for operation, extreme linkage wear, and poor control over two or more lift cylinder operations. Such arrangements may suffer from difficulties in controlling the amount of oil distributed into the separate lift cylinders thus adversely affecting the speed at which the hydraulic lift cylinders operate in a loaded or unloaded movement, moreover the cost of supplying and installing these conventional type arrangements can be quite high and they require significant space for correct installation on machinery where such space is often difficult to find. The arrangement can themselves be quite heavy which is not an advantage. In addition such arrangements can cause restrictions in the flow of hydraulic fluid and as a result they may cause overheating with consequent poor efficiency of operation. It is therefore considered desirable from a number of factors to be able to replace these existing complex valve and linkage arrangements with a single control valve which is simple to operate and which enables the desired control of hydraulic lift cylinders or the like connected thereto.

The objective of the present invention is therefore to provide a manually operable control valve for hydraulic machines such as lift cylinders which will overcome or minimise the difficulties described in the foregoing with conventional prior art arrangements. According to the present invention, there is provided a manual control valve for controlling flow of pressurised fluid to and from at least two users of said pressurised fluid, said valve comprising a valve body, said valve body having at least two pressurised fluid delivery means each being adapted for connection to a pressurised fluid supply, a distribution spool located within said valve body being both rotatable therein by manipulation of the distribution spool by an operator external to the valve body, said distribution spool including passage means adapted in selected rotational positions to direct pressurised fluid from said pressurised fluid supply to each of said pressurised fluid delivery means individually and in at least one further rotational position to direct pressurised fluid simultaneously to at least two of said pressurised fluid delivery means.

Conveniently, the spool passage means communicates with port openings in the spool at an interface between said valve body and said spool, said port openings being substantially square or rectangular.

According to a further aspect of the present invention, there is provided a manually actuated control valve for controlling flow of pressurised fluid to and from at least two users of said pressurised fluid, said control valve comprising a valve body, housing a distribution spool, having a longitudinal axis, and mounted in said valve body in a manner permitting selective axial and rotational movement of the spool relative to the valve body by manual manipulation of the spool by an operator external to the valve body. Fluid inlet passage provided in said valve body for connection to a source of said pressurised fluid and said valve body further having a pressurised fluid outlet, four fluid inlet means in said spool arranged in longitudinally spaced diametrically opposed pairs to receive pressurised fluid from the valve body inlet passage when said spool is selectably positioned axially so to do. Each said pair of inlet means being arranged to direct fluid to at least four spool outlet means located around said spool, each of said spool outlet means being adapted to direct fluid to at least one delivery means leading through said valve body when said spool inlet and outlet means are arranged in a predetermined axial and rotational position. Conveniently, each said spool outlet means, in a selected rotational spool position, is adapted to connect at least two of said delivery means leading through the valve body.

Conveniently, exhaust fluid outlet means is provided in the valve body adapted to drain fluid from the valve body exhausted from the users of the pressurised fluid.

Preferably the valve construction is configured such that two of said spool outlet means are selectably connected to transfer ports associated with said pairs of fluid delivery means leading through the valve body by relative axial movement of the spool in selected rotational positions of said spool. At the same time, other of said spool outlet means are connected to the exhaust fluid outlet means.

It is particularly preferred that all spool outlet ports and inlet ports be either substantially square or rectangular in shape, and/or be retained within a cross-sectional square or rectangular area.

The present invention will hereinafter be described with reference to a preferred embodiment illustrated in the accompanying drawings. In the drawings :

Figure 1 is a longitudinal sectional view taken along line B of Figure 7 through the valve construction with spool in a neutral position, the spool being cut-away for the purposes of clarity;

Figure 2 is a longitudinal sectional view similar to Figure 1 but taken along the line A of Figure 7 with the valve spool again in a neutral position;

Figures 3 and 4 are longitudinal sectional views similar to Figure 2 but showing the valve construction with the valve spool in two separate operational positions; Figure 5 is a transverse sectional view along line A of Figure 1 with the spool in an operative position on user 1, refer alternative view Figures 2 or 4;

Figure 6 is a transverse sectional view along line A of Figure 1 with the spool in an axial operative position part on user 1 and part on user 5;

Figure 7 is a transfer sectional view along line B of Figure 1 with the spool shown rotated axially and held in an operative position, part on user 4 and part on user 6;

Figure 8 is a transverse view taken along line C of Figure 1 showing pressure channels within the face of a distribution manifold; and

Figures 9a, 9b, 9c and 10 are several schematic drawings showing one particular form of manual operative linkages to assist in valve operation, however, several other linkage set-ups could also be used.

Referring first to Figure 1 of the drawings, the valve illustrated comprises a valve body 42 with a high pressure fluid supply inlet 46 adapted to receive high pressure fluid from a suitable supply source. The body 42 also has a fluid discharge outlet 45 adapted, when appropriately connected, to return fluid to a suitable reservoir. A distribution spool 71 is provided in a central bore 72 extending through the body 42 and is mounted to enable rotational movement within the bore and axial movement along the longitudinal axis of the bore by external operator manipulation. Both ends of the valve construction are sealed by appropriate seal means such as "0" rings 73. One end of the spool 24 protrudes through the valve body 42 for optional hand controls shown in Figures 9 and 10 enabling external operator manipulation. The hand controls shown in Figures 9 and 10 and valve explanation shown in Figures 1 to 8 are described hereinafter.

The valve body includes a plurality of pressure fluid delivery connections suitably arranged around its outer surface, each of which communicate through the valve 5 body 42 to the central bore 72 via passage means. In the illustrated embodiment there are provided pairs of pressure fluid delivery connections 1/2, 3/4, 5/6 and offset pressure portals 30/31, 32/33 and 34/35 in matching pairs adapted to deliver and receive hydraulic fluid from either end of double acting hydraulic cylinders or the like.

Referring first to Figure 1, the valve construction is shown with the valve spool 1 0 71 in a part cut away view, in a neutral operation position, in this position, hydraulic fluid supplied under pressure from a suitable source (such as a pump) to a fluid inlet connection 46 passes through the valve construction to fluid outlet connection 45 thereby enabling return of the fluid to a suitable reservoir. The inlet connection 46, with the valve in the neutral position, directs the fluid to a pair of HP chambers 9a and 9b, that

1 5 extend both axially along the surface and around the circumference of the distribution spool 71 and longitudinally adjacent to one another on either side of a circumferential land 10 formed on the spool 71. Four circumferentially spaced control vents 13 are positioned around the spool surface 71 leading into the respective chambers 9a and 9b at the ends thereof distant from the land 10. The control vents 13 enable progressive flow 0 control into and from chambers 9a and 9b.

The land 10, in the illustrated neutral position, is centrally located within the low pressure (LP) chamber 25 located in the valve body 42 opening onto the bore 72 and positioned centrally between the channels 9a and 9b. The central LP chamber 25 leads fluid to a closed centre portal 44, and closed centre outlet 11 (not shown) then outward 5 to LP manifold 50 and the outlet connection 45. As a result, pressurised fluid entering the valve body 42 at inlet connection 46 passes via chambers 9a and 9b and 25 to the portal 44, manifold 50 and the outlet connection 45. Thus in the neutral position, no pressurised fluid is delivered to any end user such as lift cylinders or the like.

Figure 2 also represents the valve construction in a neutral position but is a 0 section view taken on an opposite plane to that of Figure 1. Figure 2 illustrates a group of four substantially square or rectangular passages 19a and 19b and 14a and 14b extending radially into the spool 71 from its outer surface. The two passages 19a and 19b being diametrically opposed relative to one another and located on one side of the central chamber 9a lead to a blind internal bore 74 and the two passages 14a and 14b 5 lead to a second internal blind bore 75 within the spool 71 but the bore 75 extends to the opposite end of the spool 71 to that of bore 74. In the bore 74, a non-return ball valve seat 17 is provided. The ball valve 12 permits pressurised fluid flow outwardly along the bore 74 from the passageways 9a and 9b but not in a reverse direction. Similarly, in the bore 75, a non-return valve 22 is provided spring-loaded inwardly by a second 5 spring 16b. Again the valve 22 permits pressurised fluid flow outwardly along the bore 75 from the passageways 14a and 14b but not in the reverse direction.

In the spool 71, outwardly beyond the non-return valve 12, there is provided two passages 18a and 18b leading radially from the bore 74 to an outer surface of the spool 71. Similarly, from the circumferentially spaced passages 15a and 15b lead radially 1 0 from the bore 75 outwardly of the non-return valve 22 to an outer surface of the spool 71. The passages 18a and 18b and 19a and 19b and 14a and 14b and 15a and 15b are conveniently substantially square or rectangular when viewed circumferentially and are restricted to a positive square area on the spool's outer surface. Whilst in the neutral position (Figures 1 and 2), the passages 18a - to - 15b are sealed from leakage against

1 5 solid wall sections of the central bore 72.

Arranged between each of the passages 14a and 14b and 15a and 15b, are situated a series of user delivery vents 76 and offset porting vents 76 as illustrated in cut away view of shaft (Figure 1) showing vents 76 within valve cylinder (refer also Figures 5, 6 and 7). In Figures 5 and 6, the user delivery vents are 1 , 3 and 5 and in Figure 7, the

20 user delivery vents are 2, 4 and 6. The remaining connections 31 , 33 and 35 (in

Figures 5 and 6) and 30, 32 and 34 (in Figure 7) being offset porting vents designed to balance pressure on effective spool surface area and cut out "hydraulic lock". In each case an offset porting vent is diametrically opposed to one of the user delivery vents. These vents are preferably shaped, at least at the point of exit and or entry, in a round

25 cross-section area so as to allow the selection of more than one pair of users and offset porting vents with a progressive control.

The user vents and the offset porting vents are connected via passageways (refer Figures 5 and 6) to a transfer manifold 43 (refer Figure 8) channel 52 to 53 connecting passageways 38 and 36. Correspondingly channel 57 to 56 and 52 to 54 connecting 37 to

30 40 and 39 to 41. Accordingly Figure 7 passageways also being connected by a similar manifold 43.

Now, with the spool 71 in the neutral position as shown in Figure 2, and if the spool is moved axially to the right as shown in Figure 3, the open faces of passages 18a and 18b are brought into line with the delivery vent 1 and the offset porting vent 31. At the same time, passages 19a and 19b also move into a position to connect with the HP manifold 9a fed with pressurised fluid from inlet 46 (refer Figure 1). Simultaneously, the passages 14a and 14b move to connect user vent 2 and offset vent 30 whilst passages 15a and 15b connect the bore 75 to the LP manifold 27. Control vents 5 and the control lands or bridge 10 progressively close at a similar time to seal the LP chamber 25 by co-operation with land 11 , of the cylinder bore 72. In this configuration, passages 18a and 18b and 19a and 19b become Hp passages, and passages 14a and 14b and 15a and 15b become LP passages.

If the spool 71 is moved to the left as shown in Figure 4, the chambers 25 and 9b 1 0 are progressively closed by the spool surface in relation to the cylinder bore. Passages 18a and 18b and 19a and 19b thereby become LP passages (refer Figures 2 and 4). This action in turn redirects oil through passages 14a and 14b by forcing non-return valve 22 from its seat into an open position within passage 75. Thus pressurised fluid is allowed to flow in that direction through HP outlets 15a and 15b. As a result, with the

1 5 spool as shown in Figure 3, pressurised fluid is supplied to one end of a hydraulic lift cylinder (or the like) via a selected port and offset port 1 and 31 respectively from the inlet supply 46 (refer Figure 1). As the same fluid is exhausted to the low pressure manifold 27 from the opposite end of the lift cylinder via passages 14a and 14b connecting port 2 and offset port 30 (Figure 3) by forcing non-return valve 22 from its

20 seat to an open position. This exhausted fluid may return through bore 75 and passages

15a and 15b to the LP manifold 27. It will then be appreciated that movement of the spool to the right or left as described previously would provide a progressive connection to the inlet 46, thereby providing a control over the rate of pressurised fluid flow and the rate of actuation of a lift cylinder connected thereto. The non-return valves 12 and 25 22 situated within cylinder spool 71, prevent high pressure feed-back during this stage operation. The larger black arrows in the drawings denoting oil flow direction.

Figures 9a, 9b, 9c and 10 of the accompanying drawings illustrate an appropriate mechanism for permitting an operator to move the distribution spool 71 both axially and rotationally as desired. 0 An operating lever 59 mounted within a rotatable member 63 by a pin 67 and in turn held within a body 61 and retained by a pin 64. One end of the operating lever 59 being for manual control, the other end slidably mounted within member 63 over pin 67. The rotatable member 63 is retained in the body 61 and is further slidably connected by a pin and boss 66 to member 69. Member 69 is connected to spool 71. In this manner by 5 pivoting the lever 59 and member 61 about the pivot point 64, member 63 will be moved axially thereby causing movement of the spool 71 in an axial direction within the main bore 72. In addition, the operating lever 59 may also be rotated about axis 80 which also causes pin 66 to rotate about the axis of spool 71 thereby resulting in angular movement of the spool to desired positions. The ball 65 is adopted to positively engage in circumferential locations (recesses) upon rotation of the body 61 for the operator to feel where the desired angular positions of the spool 71 are located. The link 62 may be depressed by axial movement of the outer part of the lever 59 against biasing means to release the oblique end of the lever 62 from a position locking the ball 65 at the desired positions. It will be apparent from the drawings that having returned the spool 71 to a neutral position from the positions illustrated in Figures 4 and 3, movement of the spool 71 in a rotational direction to the left will position the spool 71 to a position such as that illustrated in Figure 2 with passages 18a and 18b and 19a and 19b, 14a and 14b and 15a and 15b in axial alignment with supply outlets 1 and 2 and offset ports 31 and 30. Operation to the right of this position passages 18a and 18b and 19a and 19b will connect the supply outlet 2 and offset port 30 to a source of pressurised fluid whilst passages 14a and 14b and 15a and 15b connect supply outlet 1 to exhaust manifold 50 via passage 20. It will further be appreciated that similar control movements to those described above are possible for each of the supply outlet port pairs 1 and 2, 3 and 4 and 5 and 6 also offset ports 30 and 31 , 32 and 33 and 34 and 35 respectively and individually with the spool 71 in selected rotational positions as defined by operation. In addition to the foregoing, it is possible to connect at least two pairs of supply outlets to the pressurised fluid supply 46 simultaneously by selectively rotating the spool part way between the positions previously identified. In this manner, as shown in Figure 6, it is possible for the pressure outlet passages to contact separate adjacent pairs of supply outlets 1 and 2 and 5 and 6 also offset ports 31 and 30 and 35 and 34 as illustrated (refer Figures 9a, 9b and 9c). It is apparent that the adjacent outlet 3 and 4 to 1 and 2 and 5 and 6 to 3 and 4 with compatible offset ports are capable of simultaneous operation in the same manner. Therefore enabling the valve to operate either as 1 valve function, 2 valve function, 3 valve function or as a complete mixing valve by selectively operating any 2 valve functions in a simultaneous manner. Figure 9a showing a lever mechanism retaining valve in line with user vents 1 and 2 held in place by ball 65 and lever 62 while in Figure 9b the valve is retained in line with user vents 5 and 6. Figure 9c shows the valve mixing user vents 5 and 6 with user vents 3 and 4. It is highly desirable that the respective ports at the interface of spool 71 and the supply outlets be round in configuration in the cylinder bore and substantially square or rectangular in configuration within the spool. As without this configuration there could be insufficient open area provided when the valve is operated for use in simultaneous manner. Finally it will be apparent from Figure 1 of the drawings that the housing can be machined and fitted with a selectable pressure relief valve 48 connecting LP exhaust manifold 47, 50 to HP manifold 49 allowing any HP build up during operation to be channelled back to the supply reservoir. The valve 48 is retained in a longitudinal neutral position as illustrated by a typical valve spring (not shown in the accompanying drawings).

Claims (7)

THE CLAIMS DEFINING THE INVENTION ARE AS FOLLOWS:

1 . A manual control valve for controlling flow of pressurised fluid to and from at least two users of said pressurised fluid, said valve comprising a valve body, said valve body having at least two pressurised fluid delivery means each being adapted for connection to a pressurised fluid supply, a distribution spool located within said valve body being both rotatable therein by manipulation of the distribution spool by an operator external to the valve body, said distribution spool including passage means adapted in selected rotational positions to direct pressurised fluid from said pressurised fluid supply to each of said pressurised fluid delivery means individually and in at least one further rotational position to direct pressurised fluid simultaneously to at least two of said pressurised fluid delivery means.

2. A manual control valve according to Claim 1 , wherein said distribution spool is also adapted for axial movement within said valve body.

3. A manual control valve according to Claim 1 or Claim 2, wherein spool passage means communicates with port openings in the spool at an interface between said valve body and said spool, said port openings being substantially square or rectangular.

4. A manual control valve for controlling flow of pressurised fluid to and from at least two users of said pressurised fluid, said valve comprising a valve body, inlet means adapted for connection to a supply of pressurised fluid whereby pressurised fluid is supplied to said valve body, outlet means adapted for connection to a reservoir for exhausted fluid, a distribution spool located within said valve body being rotatable therein by manipulation of the distribution spool by an operator external to the valve body, at least two pairs of fluid delivery passages arranged angularly spaced relative to one another with the delivery passages of each said pair being axially spaced from one another, each delivery passage of a said pair of delivery passages being adapted to deliver pressurised fluid to an end user of same or to receive exhaust fluid from the end user, said distribution spool including distribution passage means in a first rotational position being adapted to direct pressurised fluid from said inlet means to a selected said delivery passage of a first one of said at least two pairs of fluid delivery passages with the other of said first pair of fluid delivery passages receiving exhaust fluid and communicating same through said distribution spool to said outlet means, in a second rotational position being adapted to direct pressurised fluid from said inlet means to a selected said delivery passage of a second one of said at least two pairs of fluid delivery passages with the other of said second pair of fluid delivery passages receiving exhaust fluid and communicating same through said distribution spool to said outlet means, and in at least a third rotational position said distribution spool is adapted to direct pressurised fluid simultaneously to two said fluid delivery passages of adjacent pairs of said fluid delivery passages.

5. A manual control valve according to claim 4 wherein said distribution spool is axially movable within said valve body whereby in a first axial position pressurised fluid is directed into one of the delivery passages of a said pair of delivery passages, in a second axial position pressurised fluid is directed into the other of the delivery passages of said pair of delivery passages and in a third axial position pressurised fluid is directed through said spool to the outlet means without entering a said delivery passage.

6. A manual control valve according to claim 4 or claim 5 wherein said spool passage means communicate with port openings in the spool at an interface between said valve body and said spool, said port openings being substantially square or rectangular.

7. A manual control valve according to any one of claims 4 to 6 wherein at least three pairs of said delivery passages are provided distributed at spaced angular positions about said valve body.