NO131097B - - Google Patents

Description

Quantity control valve.

The present invention relates to a quantity control

valve with an associated control valve for remote control, for use

Else in a hydraulic system containing two or more hydraulic components that can be operated separately with specific, mutually arbitrary quantities of pressure medium from a common supply line via each separate quantity control valve which, by means of a maximum limitation device (throttle device) and a control

slide is designed to determine the individual, maximum amount of pressure medium to the associated hydraulic component by balancing the pressure in opposite axial directions on the control

the slide, as the regulating slide in a first axial direction is under pressure load from the pressure in front of the maximum limiting device

and in an opposite, different axial direction is under compressive load

ning of the pressure behind the maximum limiting device as well as the pressure of a pressure spring, and the regulating slide is equipped with a throat flange that cooperates with a flow opening in a slide control to regulate the supply of pressure medium quantity to the area in front of the maximum limiting device depending on the balance position of the regulating slide with increasing throttling in case of pressure predominance in the first axial direction, and that the regulating slide's balance position is adjustable by the pressure medium, which is located behind the maximum limiting device and which produces the pressure force against the regulating slide, being connected to a low-pressure source.

The present invention can be used in relatively simple installations, with, for example, two different hydraulic components, but the more hydraulic components that are included in the system, the greater the application or can provide the greater advantages. The invention is particularly intended for use on board ships, but can also be used, for example, for stationary installations on land.

One and the same hydraulic system can include a large number of hydraulic components that can be operated at different times and under different operating pressures, from a common source of pressure medium. Optionally, hydraulic components of a different nature may be connected to the system.

On board a tanker it can be connected, for example

a number of unloading pumps (one or more for each tank) which are operated separately from the hydraulic system and in addition there may be associated fresh water pumps, salt water pumps, devices for the ship's propulsion or steering, drive devices for various winches, etc.

The purpose of the present invention is to arrive at quantity control valves by which the various hydraulic components can be operated at the same time, each separately in a deliberate manner by remote control with a relatively simple arrangement of supply lines and with relatively simple control devices.

In the case of known volume control valves where the various hydraulic components are linked to a common pressure medium source and where at the same time remote control of hydraulic components with specific maximum pressure medium quantities is to be carried out, it has been recommended to use a separate supply line from the remote control center to each individual hydraulic component. For a system with, for example, 40 hydraulic components, one has been dependent on 40 separate supply lines from the remote control center and, in addition, one has been dependent on a multiple number of distribution lines in the remote control center itself in order to achieve the intended regulation with a sufficient safety margin.

An attempt has been made to simplify such known systems by using a single common ring line for a large number of hydraulic components. With such simplified systems, the large number of supply lines has been avoided, without thereby significantly increasing the pipe cross-section for the one common ring line. On the other hand, due to the high costs and the general complications that known remote control devices involve, a desired remote control has had to be dispensed with and has been referred to using relatively complicated, manually adjustable quantity control valves.

With the present invention, one particularly aims to achieve remote control of hydraulic components from a common ring line. The aim is to use a known in and of itself, relatively simply constructed quantity control valve to determine the individual, maximum pressure medium quantity for the associated hydraulic component and with the help of simple means, in addition, to be able to remotely control such a valve so that one can "regulate" down the medium pressure to the hydraulic component, continuously in the area between maximum medium flow and full s'top.

From US patent. 1,906,651 a pressure limiting valve is known. The pressure limiting valve will open at a certain pressure drop across the valve and will close at increasing pressure on the valve's discharge side. The known valve will thus open and close depending on the pressure conditions on opposite sides of the valve. A valve of this type is not applicable for the purpose according to the invention, since according to the invention, on the contrary, one must ensure a desired amount of pressure medium supplied through the valve regardless of pressure variations.

From the aforementioned patent it is known to use a membrane valve as a pressure limiting valve. Such valves are particularly exposed to vibrations during pressure changes, as the valve part has a tendency to rush back and forth. This is solved by the known design by venting pressure waves in the system. The venting takes place by an automatically acting additional valve which is placed close to the pressure limiting valve itself when pressure increases occur, allowing the high pressure medium to "bleed" off to a low pressure source.

With the present invention, however, the aim is to remotely regulate a quantity control valve from a remote control panel by direct regulation of a control valve in the control panel.

The quantity control valve according to the invention is characterized by the fact that a single remote control line for pressure medium connects the pressure control chamber and the control valve placed on the control panel, which control valve is connected to a low pressure source,

and where the amount of pressure medium in the quantity control valve can be regulated between the maximum amount of pressure medium and full stop by varying the positions of the control valve accordingly between a closed position and a fully open position.

A particular advantage of the quantity control valve according to the invention is that you can use the system's pressure medium as a remote control medium by simply carrying out regulated "draining" of pressure medium from the quantity control valve via the remote control valve and the associated simple wire connection to the remote pressure relief source. Such simple remote control can be achieved using a quantity control valve known per se by simply equipping the quantity control valve with a connection for the aforementioned line connection to the slide valve's one pressure chamber to form the aforementioned pressure control chamber. When the remote control valve is completely closed, the quantity control valve can operate as usual to limit the amount of pressure medium for the hydraulic component to the desired maximum amount of pressure medium. When the remote control valve is opened, the pressure in the pressure control chamber can be regulated separately and thereby, as needed, the pressure medium quantity of the hydraulic component can be regulated steplessly in the interval between said pressure medium quantity and full stop.

According to the invention, a solution has thus been achieved where the quantity control valve for the individual hydraulic component in a hydraulic system can ensure a certain desired amount of pressure medium regardless of occurring pressure variations in the plant and where accurate remote control of the quantity control valve between the maximum amount of pressure medium and full stop regardless of occurring pressure variations.

In the case of a quantity control valve where one end surface of the control slide adjoins a pressure control chamber which is under pressure load from the pressure behind the maximum limiting device as well as the pressure of a pressure spring and where the only remote control line is directly connected to the pressure control chamber, it is preferred that the flow capacity of the remote control line is greater than the flow capacity of a line connection between the area behind the maximum limitation device and the pressure regulation chamber.

By, according to the invention, allowing the remote control line to contain a manometer for remote reading of the pressure on the outlet side of the quantity control valve via the pressure control chamber, one can in an easily controlled manner ensure the supply of a desired amount of pressure medium and at the same time, by remote reading, have control over the pressure occurring in the pressure medium which is delivered from the quantity control valve.

It is further preferred that the valve part of the remote control valve is affected in a manner known per se by a pressure spring with adjustable pressure force, to form a maximum pressure valve with adjustable max. s i rna 1 pressure.

Furthermore, it is preferred that a shut-off valve passage is designed between the quantity control valve's drain channel and the associated hydraulic component, which is controlled by a slide whose one side is loaded by a pressure spring and whose opposite side communicates via a passage with the pressure medium in the quantity control valve's pressure control chamber. If a sufficiently large pressure drop occurs in the pressure regulation chamber, for example with a fully open remote control valve, "man""~automatically full' closure of the shut-off valve passage is achieved. If the pressure in the system's supply side drops further, the quantity regulation valve is set in the open position and when the pressure is applied to again, sufficient pressure must first build up in the quantity limiting valve before the connection to the hydraulic component is opened again via the shut-off valve passage.

Further features of the present invention will be apparent from the following description with reference to the accompanying drawings in which: Fig. 1 schematically shows the hydraulic system according to the invention;

Fig. 2 shows a section of a quantity control valve and

its associated remote control valve.

Fig. 3 shows in a section corresponding to fig. 2 an alternative design for the quantity control valve.

In fig. 1 shows two drive motors 10 and 11 which, via each axle coupling 12, 13, each drive their own hydraulic pump 14* 15- The pumps are connected to an oil tank 16 via a common line connection 17 and branch lines 17a and 17b to the pump's intake side. On the pump's outlet side, the pumps are each connected to a common bypass line 18 to the tank 16 via branch lines 18a and 18b. In the branch lines 18a and 18b, a safety valve 19a and 19b is connected respectively. On the outlet side, the pumps are further connected via branch lines 20a and 20b to a common supply line 20 which runs to a number of hydraulic components 21a, 22a, 22b; 21c, 22c; 21d, 22d via parallel branch lines 23a, 23b, 23c, 23d. Separate branch lines 23e, 23f, 23g, 23h run from the hydraulic components to a common return line 23, which is connected to the tank 16. Check valves 24a, 24b are connected to the branch lines 20a and 20b. Each hydraulic component comprises a quantity control valve 21 and one of these controllably driven hydraulic components 22. The valves 21a, 21b, 21c, 21d are connected to each respective hydraulic component 22a, 22b, 22c, 22d by means of connection lines 23i, 23j, 23k, 231 .

At 25, a remote control center control panel is shown which

via a return line 26 is connected to the tank 16. The control panel 25 is equipped with control valves 27 and 28 which are connected to a control slide in each of the safety valves 19a and 19b via each of the line connections 27a and 28a respectively. The pressure in the line connections 27a and 28a can be read via an associated manometer 30 and 31, respectively. On the control panel 25, a number of control valves 32 - 35 are also shown, each with its own associated line 36 - 39, respectively, to each of its own quantity control valve 21a, 21b, respectively , 21c and 21d. On the control panel 25 there can be placed (not shown in Fig. 1) an associated manometer connected to each of the respective lines 36 - 39. Such a manometer is shown at 40 in Fig. 2 and 3 for the one line 36 for the valve 21a.

In fig. 2, a quantity control valve 21a is shown. A supply branch line 23a and a connection line 23i to the hydraulic component (not shown in more detail in Fig. 2) are shown, which are connected to channels 41 and 42 in a cylindrical housing part 43. The housing part 43 is closed at opposite ends with end covers 44 and 45. In a first bore 46, a guide forming insert part 47 is occupied which is clamped between the end cover 44 and a shoulder part 48 in the housing part. The insert part 47 is equipped at one end with a first ring

groove 49 which communicates with the supply channel 41, while at the opposite end it is equipped with another annular groove 50 which communicates with the drain channel 42. The annular grooves 49 and 50 are connected separately via their respective cross bores 51 and 52 with a common central bore 53 in the insert part . In the central bore 53 of the insert part, a slide 54 is inserted with a stem part 5J which, at the opposite ends, is equipped with

flanges 56 and 57 which cooperate with each set of port openings in the corresponding cross bores 51 and 52. In the stem part 55, a narrow bore 58 is formed transversely through the stem part and from this bore another narrow bore 59 axially through the slide to a chamber 60 between the end cover 44 and the flange 56. At the opposite end of the flange 57, a wide flange 61 is formed which is displaceably engaged in another bore 62 in the housing part 43. Between the cover 45 and the flange 61 a chamber 63 is formed in which a compression spring 64 is engaged which normally presses the flange 61 against the adjacent end of the insert part 47- An axial bore 65 runs from the transverse bore 52 to a chamber between the flange 61 and the adjacent end of the insert part 47, while another narrow bore 66 runs from the chamber 63 to - the running channel 42 to an area just behind a throat device 67 - The throat device is shown in the drawing designed as a narrowed part of the channel 42, but in a manner known per se could consist of a disc worm insert with a precisely defined through passage or possibly a rotatable disc with the through passage placed eccentrically in relation to the channel.

The quantity control valve described, which is known in and of itself

21 works as follows:

In the one in fig. 2 shown position, where the valve 21a is shown in a fully open position, the pressure medium runs from the supply line 23a via the channel 41, the annular groove 49, the transverse bores 51, past a throttle passage between the flange 56 and the transverse bores 51 to a sliding chamber 53a in the central bore 53 and further via the transverse bores 52, the ring chamber 46, the permanently fixed throttle device'67 and the channel 42 to the branch line 23i of the hydraulic component.

Throat device 67 causes a certain pressure drop

A p from the area in front of the throat device to the area behind the throat device.

In the shown fully open position for the valve 21a to the branch line 23i, the supplied amount of pressure medium is so small (or so small than the maximum set pressure medium amount) that the pressure drop A p across the throttle device 67 becomes less than the spring pressure. The pressure in front of the throat device is transferred via the bores 58, 59 to the upper side c-v flange 56 and via the bore 65 to the upper side of the flange 61, while the pressure after the throat device is transferred via the bore 66 to the lower side of the flange 61. The compression spring 64 has a pressure force characteristic which shall balance the regulating slide 54 in the desired positions so that the desired maximum pressure medium quantity for the hydraulic component is maintained regardless of the pressure in the line 23a, as long as this exceeds a certain minimum pressure. The compression spring 64 will try to keep the valve in the open position and the forces that balance the flanges 61, 56 so that the desired maximum quantity for the hydraulic component is:

in which Pf denotes the set total spring pressure against the flange 61 and A p denotes the pressure drop across the throat device 67 and F denotes

ner end surface area of the slide, i.e. the sum of the upper end surface area of the flange 56 and the upper ring area of the flange 61 outside the flange 57 or in other words the entire lower end surface area of

the flange 61. When the quantity increases on the supply side, the pressure drop A p increases and will cause the pressure spring to be compressed somewhat

and moves the slide accordingly so that the flow through the

gene 51 becomes smaller until the pressure drop acting on the lower end surface area is again in equilibrium with the spring force and ensures a constant amount of pressure medium through the valve 21a. The pressure in the supply line is regulated via the central via the adjustable safety valves 19a and 19b, by reading via the manometers 30 and 31-

According to the invention, the quantity control valve is further regulated with respect to the medium quantity passing through steplessly within

for the range from the maximum pressure medium quantities for the hydraulic

ical component and full stop, by remote control from the control panel 25 via a simple associated control valve 32 and a single

connecting line 36' between the quantity control valve 21 and the remote control valve 32. A separate manometer 40 is inserted in the

no 36.

One end of the cable 36 is via a bore 68 in the cover 45 for

bound with the chamber 63 which forms the remote control device's pressure regulation chamber. The narrow bore 66 for the pressure regulation chamber

the lake 63 is significantly narrower than the bore 68 and the passage in the joint

ning 36, and the line 36 must be large enough to relieve the oil

quantity from drilling 66.

By means of an adjusting screw 69 in the valve 32, the

turning in opposite directions via a compression spring 70a which acts on

a valve part 70 open or close a passage through the venti-

len between the line 36 and a drain line 71 to the control panel's drain line 26 and on to the tank 16. By using a specific

stop stop for the adjusting screw 69, the compression spring can be set to a specific maximum spring pressure, so that the valve 32 can serve as a maximum pressure valve.

In fig. 2, the valve 32 is shown in a closed state. - This means that the valve 21a acts as a normal quantity control valve with the supply of a maximum quantity of pressure medium to the hydraulic component. The pressure in the pressure regulation chamber 63 can be read remotely at any time via the pressure gauge' 40 in the central unit.

By gradually opening the valve 32, an increasing regulated "draining" of pressure medium from the pressure regulation chamber 63 is carried out, so that independently of the pressure in the line 2 3a, an intentional gradually increasing pressure drop in the pressure regulation chamber 63 can be induced. This positively produced pressure drop in the chamber 63 means that the pressure spring 64 is compressed to a certain corresponding degree and that the slide 54 correspondingly throttles the medium quantity via the throat flange 56 until the spring force of the pressure spring 64 again balances the pressure drop acting on the surface F.

At fully open valve 32, the opening in the cross bore 51 is so

that is to say, completely shut off by the throat flange 56, so that one gets so

that is to say a complete stop of the medium flow in the quantity control valve and thereby a complete stop of the medium supply to the hydraulic component, while only ensuring a small flow via the line 36 to the tank 16.

As long as pressure is maintained on the supply side of the system, any hydraulic component or even all hydraulic components can be kept disconnected by opening the associated remote control valve(s). When starting up a hydraulic component, the remote control valve is completely or partially closed and the quantity control valve is brought into the desired operating position according to the remote control valve's setting.

If the pressure on the system's supply side drops out, the quantity control valve will automatically be set in the open position by the pressure force of the spring 64. When new pressure builds up on the system's supply side, all quantity control valves that have an open remote control valve will be set in place in the closed position, while the quantity control valves that have a partially or fully closed remote control valve will gradually be set to the intended position as the pressure builds up in the individual quantity control valve.

With the help of the manometer 40, the pressure in the line 36 can be read at the remote control center and the manometer can optionally be calibrated to show the corresponding supply quantity to the hydraulic component.

In fig. 3 shows a valve where the quantity control valve is closed for flow to the hydraulic component when the remote control valve is open. The quantity control valve is constructed largely like the quantity control valve in fig. 2. In addition, the outlet of the channel 42 is connected via a cylinder bore 75 with an axially offset drain channel 76 to the hydraulic component. A slide 77 with two flanges 78, 79 is inserted in the bore 75. Between the flange 78 and the bottom of the bore 75 is a chamber 80 with

a relatively weak pressure spring 81 and via the bottom of the bore runs a channel 82 with a cable connection to the drain side of the system. Between the flange 79 and a bottom cover 83, a chamber 84 is formed with a channel connection via a bore 85 and the bore 66 to the chamber 63- If a sufficiently large pressure drop occurs in the chamber 63, that is when the valve 32 is fully opened, the pressure spring 81 pushes the slide 77 in front of the drainage channel 76 and bars for the passage to the hydraulic component. If the pressure in the supply side of the system drops out, the valve 21 is set in the open position as mentioned above and if the pressure is applied again, sufficient pressure must first be built up in the chamber 63 and the chamber 80 before the connection to the hydraulic component is opened again via the drain channel 76.

Claims (4)

1. Quantity control valve with a control valve connected for remote control, for use in a hydraulic system containing two or more hydraulic components (22a-22d) which can be operated separately with specific, mutually arbitrary amounts of pressure medium from a common supply line (20) via each separate quantity control valve which, by means of a maximum limitation device (throttle device 67) and a control slide (54), is designed to determine the individual, maximum pressure medium quantity of the associated hydraulic component by balancing the pressure in opposite axial directions on the control slide, the control slide being in a first axial direction under pressure load of the pressure in front of the maximum limiting device (67) and in an opposite, other axial direction is under pressure load of the pressure behind the maximum limiting device (67) as well as the pressure of a pressure spring (64), and the regulating slide is equipped with a throat flange (56) which cooperates with a strut orifice (51) in a slide control for regulating the amount of pressure medium supply to the area in front of the maximum limitation device (67) depending on the balance position of the regulation slide with increasing throttling in case of pressure predominance in the first axial direction, and that the balance position of the regulation slide is adjustable by the pressure medium, which is located behind the maximum limitation device ( 67) and which produces the pressure force against the control slide, is connected to a low pressure source, characterized in that a single remote control line (36,37,38,39) for pressure medium connects the pressure control chamber (63) and the control valve (32,33) placed on the control panel (25) >34 , 35 ), which control valve is connected to a low-pressure source (16), and where the amount of pressure medium in the quantity control valve can be regulated between maximum amount of pressure medium and full stop by varying the positions of the control valve accordingly between a closed position and a fully open position. 2. Valve in accordance with claim 1, where one end surface of the regulating slide adjoins a pressure regulating chamber (63) which is under pressure load from the pressure behind the maximum limiting device (67) as well as the pressure from a pressure spring (64), and where the only remote control line (36-39) is directly connected to the pressure regulation chamber (63), characterized in that the flow capacity of the remote control line is greater than the flow capacity of a line connection (66) between the area behind the maximum limitation device (67) and the pressure regulation chamber (63)- 3- Valve in accordance with claim 1 or 2, characterized in that the remote control line (36-39) contains a manometer (40) for remote reading of the pressure on the outlet side of the quantity control valve via the pressure control chamber (63)- 4. Valve in accordance with claim 1, 2 or 3 characterized by a: remote control valve: '(32-35 ) valve part (70) in a manner known per se is influenced by a pressure spring (70a) with adjustable pressure force, to formation of a maximum pressure valve with adjustable maximum pressure. 5- Valve in accordance with one of the claims 1-4, characterized in that a shut-off valve passage is designed between the quantity control valve's drain channel (42) and the associated hydraulic component (22a-22d) which is controlled by a slide (77) whose one side is loaded by a pressure spring (81) and the opposite side of which communicates via a passage (85,67) with the pressure medium in the pressure regulation chamber (63) of the quantity-regulating valve.