DK175880B1 - Hydraulic pressure amplifier - Google Patents

Description

- i - DK 175880 B1

Hydraulic pressure amplifier

The invention relates to a hydraulic pressure amplifier having a supply connection, a return flow connection, a high pressure connection, an amplifier piston device comprising a high pressure cylinder with a displaceable high-pressure piston therein and a low-pressure cylinder with a low-pressure piston displaced therein and a high-pressure plunger connected to it. a first low pressure chamber and a second low pressure chamber, and with a switch valve device which controls a pressure in the low pressure chambers and has a valve element which is in a movement direction influenced by a pressure in a first control pressure chamber with a smaller pressure contact surface and in the opposite direction of movement of the a pressure in another control pressure chamber having a larger pressure contact surface, whereby at least in the second control pressure chamber means for changing the pressure are provided.

Such a hydraulic pressure amplifier is known from DE 196 33 258 Cl. It serves to bring fluid from one pressure to another, higher pressure. It is the task of the amplifier piston device. The higher pressure corresponds to the operating pressure multiplied by the ratio of the cross-sectional surfaces of the low-pressure cylinder to the high-pressure cylinder.

The low pressure piston is controlled by the switch valve, the valve element of which is also pressure controlled, whereby the same pressure basically acts on both sides of the valve element. However, the pressure in the first control pressure chamber acts on a smaller pressure contact surface, and the pressure in the second control pressure chamber acting on a larger pressure contact surface varies. In the known case, it changes from supply

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In pressure for return pressure. When the pressure in the second control pressure- I

In chamber is at the higher value, the valve element I is displaced

In to a position. When the pressure in the second control pressure chamber I

In case of fall, the valve member is moved to the second position. IN

I 5 I

Such a pressure amplifier is also available in a dual-acting output

In the lead. In this case, there are two high pressure cylinders on I

On opposite sides of the low-pressure cylinder and two high-I

In pressure pistons associated with the low pressure piston and are

In 10 movable in the high-pressure cylinders. The principal work I

way, however, is the same. Here, too, it is produced

In your pressure, the low pressure cylinder is affected by a pressure, I

which is then multiplied by the ratio of the cross sections of I

In the low-pressure cylinder and the high-pressure cylinder to produce I

At the 15 pressure at the high pressure connection. IN

In many cases, such a pressure amplifier does not work

Right. In this case, in rare situations, this occurs

In that the pressure amplifier transports fluid under a high I

In 20 re pressures, so to speak in a dynamic state. Frequent- I

In re, you see an error when the pressure amplifier is in a static I

In state, i.e. have already brought the liquid at high pressure

At the end up on the higher pressure and then have to hold it on you

higher pressure. When then high-pressure liquid is consumed

At the end of the 25th, the pressure amplifier should, so to speak, start again, I

i.e. the amplifier piston device must comply with fluid I

In higher pressure. In some cases, this does not succeed. These I

In difficulties are particularly prominent in the context of I

In double-acting pressure amplifiers. However, they are also seen

H 30 in connection with single acting pressure amplifiers. IN

Accordingly, it is the object of the invention to | IN

You could guarantee a safe start. IN

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With a hydraulic pressure amplifier as described in the preamble, this task is solved by introducing a idle diaphragm which at least in an intermediate position of the valve element connects the supply connection to the second control pressure chamber.

It is believed that a restart of the pressure amplifier after a stop is not possible if the valve element of the switching valve has removed from one of its two end positions, whereby it is not possible to actuate the low pressure chambers with pressure in such a way that the low pressure piston is moved. Such a situation occurs, for example, when the valve member is displaced so much that, with a partition, it closes the connection in the valve housing associated with the supply connection. In this case, the fluid that serves as the operating fluid can no longer come from the supply connection to one of the two low pressure chambers. So, the supply connection is completely cut off. In this situation, when a small amount of fluid is now allowed to penetrate from the supply connection to the other control pressure chamber, the valve element of the switching valve is always safely shifted to a position where at least a low pressure chamber can be affected by pressure. When this low pressure chamber has been affected by pressure, the amplifier piston device has a defined position which, by a liquid withdrawal at the high pressure connection, allows a movement of the low pressure piston and the associated high pressure piston in exactly the manner necessary for the operation of the pressure amplifier. The aperture, which may also be termed a throttle, is dimensioned in such a way that it allows only the amount of fluid to pass through which is necessary to be able to displace the valve member to it.

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desired position from standstill. In operation, that is, when you reach

the valve element moves back and forth, plays wavy

the supply of water through this blender is practically none

role. Thus, in practice, the aperture only affects the static state.

Hereby, it is preferred that the idle aperture is only at intermediate intervals

sition connects the supply connection to the other I

control pressure chamber. In this embodiment, it is avoided that

10 also in other valve element positions, a pressure equalization may occur

connection between the supply connection and the other control I

pressure chamber. This could possibly cause problems for you

slow operation of the pressure amplifier, where only a small amount of I

the liquid is withdrawn on the high pressure side. H

15 I

Preferably, the idle aperture is disposed in a conduit which H

can be interrupted by a displacement of the valve member. With

in this embodiment it is practically possible that the aperture au- H

connect automatically to the supply connection only when I

The valve member is in the intermediate position. Interrupt I

the wiring is done automatically at the valve element operation

movement. Further precautions are therefore not necessary

dike. IN

Preferably, the idle aperture is disposed in the valve member. IN

It simplifies the production of the switch valve. Interventions in I

the valve body housing is practically not necessary. Al- I

small changes in the valve element are sufficient

to introduce the aperture. H

30 I

Preferably, the valve member is formed as a slider which H

with a circular flange abuts the inner wall of an H

valve housing, and separates a first connecting chamber from I

DK 175880 B1 - 5 - another connecting chamber, whereby the cord opens to the extent of the flange. One connection chamber in a valve element position connects the supply connection to a pressure chamber, while the other connection chamber in this position connects the other low pressure chamber to the return flow connection. When the valve element has changed position, conditions are just the opposite. The flange thereby separates the two connecting chambers so that the two low pressure chambers are separated in liquid form. For this, a certain 10 flange widths are required, ie. a certain extent in the axial direction which then, when the valve element is in the intermediate position, causes the input connection, ie. the connection associated with the supply connection can be blocked. When the cord is then discharged to the circumference of this flange, it creates the possibility that the liquid from the supply connection flows through the cord and the aperture to the second control pressure chamber, where it builds up a pressure sufficient to displace the valve element to a end position.

20

Preferably, the groove has a V-shaped cross section. You can use the groove to take over part of the throttle action.

A V-shaped groove is relatively easy to manufacture when machining the valve member in a lathe.

25

Preferably, the conduit has a section extending parallel to the direction of movement of the valve member. Such a section can be easily manufactured, for example by drilling. However, it is also possible to make this section already 30 by casting the valve member.

In a preferred embodiment, it is further contemplated that the valve member has a retainer link connecting

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the sewing connection with the second control pressure chamber when I

the valve member has been displaced by the pressure of the second I

control pressure chamber. The holding aperture then connects the supply connection I

pressure into the second control pressure chamber. That is

5 one is able to offset minor fluid losses in the second H

control pressure chamber, which can occur, for example, by leaks.

If less fluid loss is allowed, the valve member can feed

rests in the valve body with a somewhat looser fit. This leads you

again to a lesser friction and thus to a faster I

10 displacement of the valve member. The holding blend allows H

the pressure at the supply connection is "frozen" in the other- H

the control pressure chamber until the second control pressure chamber de- I

loaded. In this case, the fluid flowing into the

Of course, through the holding aperture, not enough to

15 maintain the pressure in the second control pressure chamber. Valve I

the element can be displaced under the pressure of the first control- H

pressure chamber and occupy its end position. In this second po-

sition, the holding aperture is no longer associated with supply H

connection so that at least you no longer happen

20 is a pressure build-up in the second control pressure chamber through the holding I

the blend. Also, no pressure build-up occurs through the blank

the idle aperture when the idle aperture is only connected to H

the supply connection in the intermediate position. H

Preferably, the retaining mixer is arranged in a valve element wall, I

limiting a connection chamber. It is a special one- H

It is also possible for a position-correct control of a liquid H

transport from the supply connection to the other control- H

pressure chamber. Liquid can then only flow through the holding blend, H

30 if the corresponding connection chamber is pressurized H

of the supply connection. H

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Hereby it is preferred that the retaining aperture opens into the conduit section. In other words, it is quite possible to produce the holding blend by a bore in the wall of the valve element surrounding the conduit. Of course, if required, one can also insert a blending insert into such bores.

In the following, the invention is described in detail on the basis of preferred embodiments of the drawings which show:

FIG. 1 a single-acting pressure amplifier

FIG. 2 shows a double acting pressure amplifier 15 FIG. 3 is a schematic cross-section through a switch valve with the valve member in a first position

FIG. 4 is a schematic cross section according to FIG. FIG. 3 through a switching valve with the valve member in an intermediate position

FIG. 5 is a schematic cross section according to FIG. FIG. 3 through a switching valve with the valve member in a different position 25

One in FIG. 1, a single-acting pressure amplifier 1 has an amplifier piston device 2 with a high pressure piston 3 in a high pressure cylinder 4 and a low pressure piston 5 in a low pressure cylinder 6, whereby the high pressure piston 3 and low pressure piston 30 5 are connected to each other via a connection 7 in such a way that the connection can be pressure overloaded. The low pressure piston 5 divides the low pressure cylinder 6 into a first low pressure chamber 6a and a second low pressure chamber 6b.

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DK 175880 B1 I

The pressure amplifier has a supply connection IN, a re- H

turbine connection R and a high-pressure connection H. Provide- I

the inlet connection IN is connected to the high-pressure cylinder I

5 4 via a first check valve 8. The high pressure cylinder 4 is H

connected to the high pressure connection H via another contract- H

valve 9. I

The movement of the low pressure piston 5 is controlled by a switching valve I

10 10, having a valve member 11 which in the present invention

cases are designed as a slider. Valve element 11 on- I

act from its one front with the pressure of a first control I

pressure chamber 12 connected to the supply connection

gene IN via a first pilot line 13. The opposite side of H

The valve element 11 is affected by the pressure in another control H

pressure chamber 14. The pressure contact surface of valve member 11 is

larger in the second control pressure chamber 14 than in the first H

control pressure chamber 12, for example twice as large. H

The switch valve 10 has an inlet 15 connected to I

supply connection IN. Further, the switch valve I

10 shows a first output 16 connected to the first H

low pressure chamber 6a and a second outlet 17 connected H

with the second low pressure chamber 6b. In the position shown H

25, the valve element 11 immediately produces a connection H

between the two outputs 16, 17 and thus short the two H

low pressure chambers 6a, 6b. The first low pressure chamber 6a is in H

immediate connection with return connection R. H

30 The second control pressure chamber 14 communicates with a pipe H

lot line 18, as with a first branch 19 and a second branch H

20 opens into the wall of the low pressure cylinder 6. At the same axial H

height as the first branch 19 also results in a supply H

Γ · 1 --- ---- ----. i — ι DK 175880 B1 - 9 - channel 21, which is connected to the supply connection IN.

At the same height as the second branch 20, a return channel 22 opens connected to the return connection. The low pressure piston has a circumferential groove 23 which, in one of the 5 low pressure piston 5 end positions, connects the mouth of the branch 19 with the mouth of the supply channel 21 and in the second position of the low pressure piston connects the mouth of the second branch 20 with the mouth of the return channel 22.

10 The valve member 11 has a channel 24 which in the valve member 11 in FIG. 1, the input 15 connects to the second output 17 and thus to the second low pressure chamber 6b. From this channel 24, a conduit 25 is provided in which is arranged a retaining diaphragm 26. When the valve member 11 is in its second position, the input 15 and thus the supply connection IN is connected to the second control pressure chamber via the retaining diaphragm 26.

Further, an idle aperture 27 is connected to the second 20 control pressure chamber 14, which is then connected to the input 15 and thus to the supply connection IN, when the valve element 11 is in an intermediate position. This is explained below in connection with FIG. 3 to 5.

The pressure amplifier operates as follows: In the switching position shown in the switch valve 10, liquid flows through the first check valve 8 into the high pressure cylinder 4 and thus presses the high pressure piston 3 and low pressure piston 30 downwards as the volume of the high pressure cylinder increases. The directions hereby refer to the orientation in the drawing. In reality, the spatial position of the pressure amplifier 1 plays virtually no role.

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As soon as the circumferential groove 23 connects the supply channel

In lane 21 with the first branch 19 of the second pilot line 18, I

The more pressure from the supply connection IN into the other I

In 5 control pressure chamber 14. Since this works on a larger surface I

As in the first control pressure chamber 12, the valve member is displaced

In the ment 11, so that the input 15 is connected to the second low

In pressure chamber 6b. Thus, in the second low pressure chamber I

In 6b the pressure at the supply connection IN. This pressure I

10 now presses the low pressure piston 5 and thus also the high pressure piston I

In spot 3 upwards while reducing the 4 I of the high pressure cylinder

In volume. Liquid located here is displaced via it

In second check valve 9 for the high pressure connection H. Also at I

fluid loss from the second control pressure chamber 14 which, for example,

15 piles may occur due to leakage, change valve element- I

Not in the 11 position of the team. The pressure in the second control pressure chamber I

On the contrary, via the holding aperture 26, through which I

In the liquid from the inlet 15 can run into the second controller

In pressure chamber 14. I

I I

When the low-pressure piston 5 is displaced so far that it circulates

bend groove 23 connects the mouth of the return channel 22 I

And the second branch 20 of the second pilot line 18 with each other,

Pressure relief of the second control pressure chamber 14 I occurs

I 25 and the valve member again switches to the one shown in FIG. 1

In sition. IN

In FIG. 2 shows a double-acting pressure amplifier 1 ', wherein

In the same elements are provided with the same reference numbers. I I

Instead of a high-pressure cylinder 4, there are two high-pressure cylinders

In relieve 4a, 4b, wherein corresponding high pressure pistons 3a, 3b I

You can shift. Similarly, there are also the first two contractions.

In valves 8a, 8b and two other non-return valves 9a, 9b, where-

Through fluid access to and exit from the high-pressure cylinders 4a, 4b occurs. The low pressure piston 5 is thereby operated through pressure in the two low pressure chambers 6a, 6b, so that the switching valve 10 'also couples the connection from the second low pressure chamber 6b to the return flow connection R. Depending on the position of the valve element 11', the input 15 is either connected to the first output 16 connected to the first low pressure chamber 6a or to the second output 17 connected to the second low pressure chamber 6b. The low-pressure chamber 6b, 6a, which is not connected to the input 15, is then connected to a connection 28a, 28b, which in turn is connected to the return flow connection R.

Here, too, the valve member 11 has a retaining aperture 26 and an idle aperture 27 connected to the second control pressure chamber 14.

FIG. 3 to 5 now schematically illustrate the shift valve 10 'with a valve housing 29 in which the valve element 11' is disposed.

20

Not shown in detail are the two control pressure chambers 12, 14 with their different pressure contact surfaces. The control pressure chamber 12 is at the left end and the control pressure chamber 14 at the right end.

25

The valve member 11 'has in its axial center an orbital flange 30 abutting the housing 29 from within and separates a first connecting chamber 31 from a second connecting chamber 32. The two connecting chambers 31, 32 have a bead at their axially outer end. 33, 34 having a sufficient axial length to seal the connections 28a, 28b when the valve member 11 is in the corresponding position.

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In Dotted lines, the orifices on the two outlines

times 16, 17. In the position of the valve element 11 connected

there is one connecting chamber 31 inlet 15 with it

In the first output 16 and the second output 17 with the one to- I

end 28b leading to the return loop connection. IN

I When the pressure amplifier has not worked for a while and I

Therefore, in the switching valve 10 'has not switched on, it can fo

In 10, the valve element moves to position I

As shown in FIG. 4, where the flange 30 closes the mouth of the entrance 15

I thing. In this position, the bead 34 covers the connection I

In the 28b mouth. In this situation, the pressure amplifier cannot

You start again. Such a displacement may, for example, occur

In 15, when the pressure in the second control pressure chamber 14 is controlled

You get so much because of leaks that there is excessive weight

with the pressure chamber 12. I

To prevent such a situation, a circular groove is

Placed on the extent of the flange 30, which in the present invention

In execution is V-shaped. This groove is via the idle aperture

27 connected to an axial bore 36 disposed in the valve

In the tile element 11 'and opens in the second control pressure chamber I

14. The axial bore 36 extends below the flange 30. I

I 25 I

In the region of the connecting chamber 32, the retaining mixer I is

26 positioned in the wall of the valve member 11 ', i.e. between axial- I

In the bore 36 and the connecting chamber 32, whereby the holding bee I

In the 26th may be a bore going through this wall. IN

I 30 I

In the idle blender, the effect of liquid from the entrance I

I 15 can enter the second control pressure chamber 14 and there is opened

You build a pressure sufficient to displace the friend

DK-175880 B1-13 attachment member 11 'to the second end position shown in FIG. 5th

In this end position, the second low pressure chamber 6b of the low pressure cylinder 6 is actuated by pressure. As long as no liquid is taken from the high-pressure side, the low-pressure piston 5 does not perform any movement. However, as soon as fluid is taken from the high pressure side, the pressure amplifier can begin to work. Thus, there is a steady state at all times. The pressure in the second control pressure chamber 14 also remains in that of FIG. 5, the valve element position 11 shown is continuously maintained because liquid 10 can flow through the retaining mixer 26 from the second connecting chamber 32.

Claims (10)

14. I I Patent Claim I 1. Hydraulic pressure amplifier equips a supply connection II, a return loop connection, a high pressure connection II, an amplifier piston device comprising a high II pressure cylinder with a displaceable high pressure piston II and a low pressure cylinder with a displaceable low II piston connected therewith. with the high-pressure piston and II 10, the low-pressure cylinder divides into a first low-pressure chamber II and a second low-pressure chamber, and with a switch valve device which controls a pressure in the low-pressure chambers and has a valve element which in a movement direction is influenced by a pressure in a first control pressure chamber having a smaller II pressure contact surface and in the opposite direction of movement II of a pressure in another control pressure chamber with a larger II pressure contact surface, whereby at least in the second control pressure chamber there are means for changing the pressure, II characterized by the introduction of an idle diaphragm II 20 (27), as at least in an intermediate position n of the switching element (11, 11 ') connects the supply connection (IN) to the second control pressure chamber (14). IN Pressure amplifier according to claim 1, characterized in that the idle blender (27) only connects the supply connection (IN) to the other control pressure chamber (14) in the intermediate position. IN Pressure amplifier according to claim 2, characterized in that the idle blender (27) is arranged in a line (25) which can be interrupted by a displacement of the valve element I (11, 11 '). I DK 175880 B1 - 15 - Pressure amplifier according to claim 2 or 3, characterized in that the idle aperture (27) is arranged in the valve element (11, 11 ') Pressure amplifier according to one of claims 1 to 4, characterized in that the valve element (11, 11 ') is formed as a slider which, with a circumferential flange (30), abuts against the inner wall of a valve housing (29) and separates. a first connecting chamber (31) from a second connecting chamber (32), whereby the conduit (25) opens to the extent of the flange (30). Pressure amplifier according to claim 5, characterized in that the conduit (25) opens into a groove (35) arranged in the flange (30). Pressure amplifier according to claim 6, characterized in that the groove (35) has a V-shaped cross section. Pressure amplifier according to one of claims 5 to 7, characterized in that the line (25) has a section which runs parallel to the direction of movement of the valve element (11, 11 '). Pressure amplifier according to one of claims 1 to 8, characterized in that the valve element (11, 11 ') has a holding, diaphragm (26) connecting the supply connection (IN) with the second control pressure chamber (14) when the valve member (11, 11 ') has been displaced by the pressure in the second control pressure chamber (14). DK 175880 B1 I 16. I Pressure amplifier according to claim 9, characterized in that the holder mixer (26) is arranged in a valve element wall (11, 11 ') which limits a connecting carton (32). IN Pressure amplifier according to claim 10, characterized in that you hold the blend (26) into the conduit section of the conduit (25). IN 10 I