DE2221388A1 - Flow medium operated piston pressure booster - Google Patents

Description

Dr. Ina. R Negendank 9 9 9 1 Q β Q

Dip! .Ing, H Haück- D-IdI. Phys. VV.Schmitt LLL NOO

Dipl. Ing. E. Grealfs - Dipi Ing. W, Wehnert 8 MJnzhen 2, friozartstraße 23 Telephone 5380586

The Bendix Corporation

Executive offices. .

Bendix Center ■

Lawyer s file. M ~ 2156 Southf Md, Mich. 48075, USA '

30 April 1972

Attorney File M-2156 Fluid Actuated Piston Pressure Booster

Liquid jet cutting, in which different-materials be processed with the help of a high pressure liquid jet has long been known and is being tried demonstrated »A practical industrial application of this process has so far been due to various technical Problems not possible, one of which is the difficulty of creating suitable high pressure fluid sources.

This is a difficult problem because of pressures in general over 2000 kp / cm2 are required and in most applications Pressures in the range of 3500 - 50Q0 kp / cm2 or more are required, and liquid under these pressures must be continuously supplied, to achieve a clean machining of the workpiece.

In addition, in some cases the blasting device about, the workpiece can be moved. z »B. with the automatic

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Cutting patterns, and since flexible hydraulic lines and couplings are not available for such pressures, a source of fluid appropriate in size and weight is of great advantage

So far, for the continuous generation of a liquid stream only known double-acting stepped piston pressure intensifiers with pressures of this magnitude.

However, such pressure amplifiers are not very satisfactory ,, because of the risk makes a bending at these high pressures in this device particularly difficult because a three-point support is _used}, and the components must be very large to avoid of setting during the lifting movements and rigidly trained. Additionally, because of the end-to-end arrangement of the chambers, the intensifier becomes excessively long and bulky.

As a result of these deflections, the piston sealing problems also increase and the heavy construction requires a considerable Seal maintenance and thus excessive dead times.

Another well-known pressure intensifier that has a double floating piston contains, avoids some of the difficulties described above, the valve arrangement of this pressure intensifier however prevents full simultaneous printing

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Actuation of the individual cylinders and thus a noticeable overlap of the pressure strokes of the individual. Cylinder ·.

In order to avoid these disadvantages, the invention creates a piston pressure booster which is able to continuously generate a flow of liquid with pressures of the order of magnitude of 5000 kp / cm2 and which contains two pressure cylinders which are controlled independently of one another via valves in such a way that a simultaneous full pressurization of both cylinder chambers is obtained. ,, so that, regardless of the delay resulting from the considerable compression of the liquids at these pressures, an overlap is made possible _o

Further features and advantages of the invention emerge from the claims and the following description in FIG Connection with the drawings »It shows:

Figure 1 is a schematic representation of the double pressure booster with associated valves and hydraulic lines j

FIG. 2 shows a schematic representation of the double piston with the associated valve arrangement in a central one Level of the amplification cycle j

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Figure 3 is a schematic representation of the double piston with associated valve arrangement at a later point in time of the amplification cycle j

FIG. 4 shows a schematic representation of the start-up valve and the control valves at the start of the boosting process y

Figure 5 is a front view of a particular embodiment of the double piston pressure booster:

Figure 6 is a view of the pressure booster in the direction the arrows 6-6 of Figure 5 $

FIG. 7 shows a section along the line 7-7 of FIG. 5 j

Figure 8 is a view of the pressure booster in the direction of arrow 8-8 of Figure 5 "

In detail, the figures and in particular the figure show a pressure booster with two control pressure actuated by two Control valves 14 and 16 controlled pressure cylinder units 10 and 12 *

Each cylinder unit 10 and 12 contains a piston 18 and 20, respectively, arranged in a cylinder 22 and 24, respectively.

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The pistons consist of interconnected head pieces of larger diameter 26 and 28 and head pieces smaller diameter 30 and 32, the

in upper chambers 34, 36 and lower Chambers 38 and. 40 of the cylinders 22 and 24 arranged are·

This arrangement forms the basic pressure booster _r whereby a low-pressure medium is supplied to the upper chambers 34 and 36, acts there on the pistons 18 and 20 and, due to the difference in area of the connected piston head pieces, serves to increase the pressure of a working fluid introduced into the lower chambers 38 and 40.

In one embodiment, a head piece with a large diameter of 50 mm and a head piece with a small diameter of 16mm to create a boost ratio of 18: 1 is used *. At a supply pressure of 350 kp / cm2 to the upper Chambers, a pressurization of the working fluid of 63QQ kp / cm2 can be achieved

The fluid used to generate pressure is the upper chambers via pressure lines 42, 44, respectively

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fed to the upper part of each cylinder 22 and 24 " open out - so that the large one above each head piece Diameter 26 and 28 located space is pressurized can be.

4th

A source of fluid 46, e.g., a 350 kp / cm2- oil pump, can contain a pressure accumulator 48 and the connection with the lines 42 and 44 via control pressure actuated. Regulate control valves 14 or 16 ..

Each control valve 14 and 16 includes one in one Valve bore 54 or 56 arranged displaceably Valve body 50, 52.

The valve bodies 50 and 52 control by their position in the respective bore 54 and 56 the connection between the openings 58, 60 or 62, 64 with the openings 66 or 68, and the valves 14 and 16 thus work as 3-way valves ..

The openings 58 and 60 are connected to the fluid source 46 _{via the lines 70 1 72;} while the openings 62, 64 are connected to the sump 74- via the lines 76, 78 and 80 _o The openings 66 and 68 are connected to the lines 42 and 44, respectively.

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In the position of the valve body 50 shown in FIG. 1, the part of the upper chamber 34 of the cylinder 22 above the head piece of large diameter is connected to the sump 74 _; since the opening 58 is blocked by the web 82, while in the illustrated position of the valve body 52 the upper chamber 36 of the cylinder 24 above the head piece of large diameter 28 communicates with the fluid source 46, since the web 84 blocks the opening 64 · In the opposite position of the valve bodies, the opposite is the case, since the web 86 blocks the opening 62 and the web 88 blocks the opening 60.

The position of each valve body 50 and 52 correspond sponding in the valve bore 54 · bzwo 56 is transferred to the opposite ends 90 or 92 ₁ · 94, 9.6 exerted. Control pressures regulated, these. · Are pilot pressures produced in the cylinders 22 and 24 by the displacement of the pistons 18 and 20. This is accomplished via control lines 98, 100, 102, 104, with the chambers 1Q6, 108, 110 and 112 in conjunction -stehen _r respectively are arranged behind a corresponding valve body end 90, 92, 94 and 9 & i.

The control line 98 is connected to a cylinder 22 with a ^ -

brought control port 114 connected so that they are in the ^:

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lowest position of the piston 18 is open and the pressure of the fluid source 46 in the chamber 106 directs. The control line 100 is connected to the opening 11.6 located in the cylinder 24, so that at an intermediate point in the downward movement of the piston 20, the opening 116 becomes free and the pressure of the fluid source into the chamber 108. The control line 102 is connected to the control opening 118 in the cylinder 22, so that in a similar manner at an intermediate point in the downward stroke of the piston 18, the opening 118 becomes free and directing the pressure of the source of fluid into chamber 108. The control line 104 is with the control port 120 connected in the cylinder 20, so that when the lower stroke point of the piston 28 is reached, also becomes free and directs the pressure of the fluid source into the chamber 110.

To the valve body 50, 52 in the by the application To hold positions reached with the control pressures, mechanical detents 122 and 124 can be provided will. Further options, e.g. a hydraulic one Locking of chambers 106, 108, 110 and 112 or magnetic detents are in the form described later also usable

To ensure correct synchronization of the Pistons 18 and 20 during the start of the stroke is a start-up

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valve 126 provided that the lines 128 and I30 briefly pressurized and causes the valve body 50, 52 to be described in more detail below Manner, while these lines are normally positioned via line 132, as shown in Figure 1, are connected to the sump 74 and do not affect the operation of the device.

The working fluid source 134 constantly supplies the lower chambers, 38 and 40 übeildie lines I36 and '138 ₉ Eückschlagventile 140 and 142 and the lines 144 and 146 with working fluid in many cutting operations, preferably water is used as a cutting fluid and there is also such a device described Since oil is preferably used in hydraulic systems such as the pressure _{booster according to the invention, the result is a two-fluid system o} The water is fed into the device according to the invention under relatively high pressure, e.g. different fluid and working media, the working fluid was fed in with almost no pressure and the fluid alone had to cause the return stroke. As a result, the influence of the formation of bubbles in the working medium source 134 on the volumetric efficiency of the system is kept very small, since its volume is greatly reduced from the start. ,.

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In addition, there is no need for a special return device for the fluid, since the high-pressure working medium each piston pushes up when there is no fluid enters their corresponding upper chambers 34 and 36, respectively.

During the compression stroke of each piston 18, 20 is. the work equipment to the consumer, e.g. the liquid jet cutting system described: 148 via the non-return valves 150, 152 and lines 154, 156 and 158 routed » A changing and overlapping printing the cylinder thus causes the high pressure liquid is fed to the liquid jet cutting system.

The liquid jet cutting system can have an intermediate container 160 and a nozzle 162 included.

The mode of operation of this device after start-up is explained in a simple manner using FIGS. 2 and 3. When the pressure booster is pressurized, as shown in FIG Chamber 34 of the cylinder 22 is connected to the sump, the piston 20 moves down and pressurizes the liquid in the lower chamber 40 under pressure _{or the like}

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When the piston 20 reaches the position shown in Figure 2, the control port 116 is free and durdh the fluid under pressure applied .. This pressure acting in the chamber 92 via the control line 100 pushes the valve body 50 in the in figure 2 . left position _shown; in which a pressurization of the upper chambers 34 of the cylinder 22 is initiated via the line 4-2.

Thus, both pistons 18 and 20 move together below (although slower than the piston 20 alone) until the piston 20 reaches the position shown in Figure 3, in which the control opening 120 becomes free * The resulting: Pressurization of the control line 104 and the chamber 110 connected to it causes a displacement of the valve body 52- in the position shown in Figure / right, in which the chamber 36 is in turn connected to the sump 74 is.

In the meantime, the piston 22 has that shown in FIG Reaches position and continues to move down, thus maintaining the outlet pressure.

The size of the overlap is chosen so that the entire compression of the liquid, the lines, etc _{o has} taken place and the pressure of the through the cylinder unit

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2221383

10 compressed working medium before pressure venting of the cylinder unit 12 the operating pressure of the system has reached so that there will be no fluctuations in the output current or pressure.

It was found - that the for pressures in the said Order of magnitude, i.e. 5000 kp / cm2, required degree of overlap is considerable and only through full simultaneous pressurization of the two pressure intensifiers can be achieved during a certain period of time.

For example, in the system described and with a stroke of 75 mm, the control openings 116 and 120 of the Cylinder unit 12. and the control ports 114 and 118 of the Cylinder unit 10 arranged at a mutual distance of 12.5 mm, and the resulting compression stroke is of the order of 25 mm, in order to avoid such pressure fluctuations to be kept very small «.

The piston 18 then moves further downwards (but now more quickly) until the opening 118 becomes free and thereby the control line 104 and the chamber 112 are pressurized, whereby the cylinder unit 12 in turn is switched on in a manner similar to that of the working stroke of the piston 20. When the piston 18 is in the lower stroke position reached and the opening 114 is free, the control line 98 and the chamber 106 are pressurized, whereby

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the pressure booster 10 is switched off *

The work cycle repeats itself again and again · ,, for so long Fluid is supplied «, The system described was for a number of periods of 3.65 Hz to generate designed for an output flow of 3 * 8 l / min at 4900 kp / cm2, ·

The mode of operation of the start-up valve is explained with reference to FIG. In the position shown, the valve body 164 directs pressure medium from the source 46 to the chambers 168 via the line 166 and the opening 167 and the control valves 14 and 16, via the opening 171 and the lines 172 and 17 -c the floating pistons 176 and 178, the valve bodies 50 and 52 in the in Figure ·. 4, whereby your workflow is properly synchronized. The valve body J] 64 only remains. temporarily in this position until a pressure builds up in the line 180 and the chamber 182 _r of the valve body 164 in the sense of the figure. 4 to the right against the force of a spring 184 into the position shown in FIG. The web 186 then blocks the opening 167, while the web 188 moves and releases the opening 190 and connects the lines 172 and 174 via the branch line 192 with the sump 74- _o

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The response behavior of the valve body 164 is determined via an opening 194 and a pressure accumulator 196 controlled, so that its displacement is delayed until the valve bodies 50 and 52 have switched. Optionally can electronic actuation and delay or other arrangements can be used for this purpose.

This ensures that the valve bodies are in the correct position at the start of work Initiate workflow.

In connection with the start-up of the liquid stream must irf the feed chambers are sufficiently throttled to a to prevent too fast downward stroke of the piston, since them to the structure of the operating pressure counteracts a relatively lower resistance "which wisLeraim could lead to a loss of synchronization _r if the return stroke of the Piston 18 is not ended before the piston 20 reaches the opening 116 and thus initiates a premature working stroke of the piston 18. In order to achieve this, flow and throttle points 198 and 200 can be provided in the lines 70-72, or the associated openings simply have appropriate dimensions for limiting the maximum flow.

Figures 5-8 show a special embodiment

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play ·, Es and two side by side Cylinder units 202, 204 provided, by a . Upper distributor plate 206, a middle distributor plate 208 and a lower distributor plate 210 connected are connected to each other, by bolts 212 and 214 ·. attached are.

Each booster cylinder unit 202 and 204 includes a control valve assembly 216 and 218 with a start-up valve therebetween. 220 _o

he
One of the pressure accumulators 4-8, as in Ligur 1 schematically

is, ' . .
shown / corresponding header 222 can be mounted between and below the cylinder units 202 and 204- and connected to the line 224- and channels not shown in the upper manifold plate 206 ·

Eigur 7 shows in section the cylinder unit 204- and their associated control valve. 218 “that. For both cylinder units 202 and 204- has the same structure. This contains a piston 226 with an upper head piece large diameter 228 ,, which is slidably disposed in an upper cylinder 230 and over itself adjusting coupling piece 231 with a through the middle V.teilerpl & ttffl 208 running and in one lower cylinder 234- arranged lower head piece of smaller diameter 232 is connected »

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The upper cylinder 230 includes an outer bearing bush ■ 236 and an inner one provided with the control openings Wear sleeve 238, of which the lower control shut-off opening 240 is shown and both preferably as narrow slots are formed · This shape of the control openings causes pressing and abrasion of the seal when the piston 226 is moved in the inner wear sleeve 238.

Each control opening is associated with openings not shown in the outer sleeve. 238 in connection, which in turn are connected to the control lines 242 and 244.

The piston 228 is at the upper end of the cylinder 230 in an Eederscheibe stop 246 and at the lower end of the cylinder dampened in a spring ring 248.

The lower cylinder 234 contains an outer sleeve 250 drawn over an inner sleeve 252, which gives the inner sleeve 252 a prestress against the application of pressure . This has proven to be a cylinder design suitable for extremely high pressures.

The dynamic sealing of the small diameter head piece 232 during the printing stroke is achieved in this case. management example by means of a leakage control sleeve 254 achieved »This well-known arrangement creates under high

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Pressure conditions due to a pressure difference the sleeve 256 a seal <*. Liquid that at the stuffing gasket 258 flows past, gets into both the gap 260 and the annulus between the head piece small diameter 2J2 and the sleeve · Because the gap 260 ends in a static gasket 262 the liquid held there while a leakage flow past the small diameter header 232 can flow off and through the ring slot 264 ·, the channel · 266 and line 268 can be collected. This creates a pressure difference on the during the pressure stroke Bushing 256 generates, - whereby the bushing 256 is the head piece Small diameter gripped tightly, but allowed free displacement during the return stroke

The control valve. 218 contains a sliding, in one: Valve bore 272 arranged and positioned by means of auxiliary pistons 274, 276 and 278 valve body 270 * Der Valve body 270 controls the connection of channel 280 and the opening 281, which is connected to the return line 282 are, as well as the connected channels 284, 286 and 288 and the supply line 224th and the connected Channel 290 by moving depending on its location in the bore either the opening 292 or the opening 294 is blocked.

The auxiliary piston 274 is through the control port 240 and the control line 244 actuated pressure received,

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the auxiliary piston 276 on the pressure, the. about those with the ON control port of the opposite cylinder unit 202 connected control line 296 is supplied, while, the piston 278 is actuated with the pressure obtained via the line 298 from the start-up valve 220 (FIG. 6).

Two permanent magnets 300 and 302 are used for locking, whereby the valve body 2? Q by magnetic forces in one or the other situation is held until this of. the auxiliary piston are overcome.

Leakage past the auxiliary pistons 274, 276 and 278 is _{collected via the A US} savings 304 »306 at each end of the bore 272, as well as the openings 294 and 308 and the channels 310 and 288 and passed on into the return flow channels 286, 284.

To reduce the leakage flow at the large diameter 288 past and collect from the dam openings and ^ a Filling of the space formed during the return stroke behind the large diameter head piece 228 by means of a return flow To enable a line 312, which in turn is connected to an annular channel 316 Channel 314 is in communication, and an opening 318 is provided.

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Thus, the fluid can be displaced

piece
from above the head / "228 during the return stroke! .e. does not flow via the opening 294, the channels 288, 286, 284. into the line 312 and via the channels 314, 316 and 318 into the area behind the head piece ,, whereby the counterforce is kept very small during the return stroke.

The work equipment is via the line 320 and the Inlet check valve 322 is supplied and arrives via the channels 324, 326 in the lower cylinder 234 »during of the pressure stroke, the fluid enters the channels 326, 328 at the outlet check valve ·. 330 over in the Slot 332, through channel 340 (Figure 8) to AusHaßkanal 342. The fluid jet cutting nozzle can be screwed directly into channel 342 around the Record output stream

The embodiment described operates in the using the schematic illustrations in Figures 1-5 described way.

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Claims (1)

The Bendix Corporation, ._ <., ... Executive offices
Bendix Center Southfteld, Mich. M-8075, U.S. Attorney File M-2156 April 30, 1972 PATENT CLAIMS 1 .. Fluid-operated piston pressure booster with two individual boosters, each consisting of a stepped piston-cylinder unit, two valves for controlling a low-pressure fluid flow to the cylinder chamber above the large surface section of each piston, a supply device for the pressure supply of a working medium other than the fluid into the cylinder chamber below the small surface section of each piston, and an outlet device for collecting the working medium displaced from each cylinder during its pressurization caused by the fluid, characterized by a control device (98, 100, 102, 104, 114, 116, 118, 120) by which the fluid can be fed alternately to the individual amplifiers (10 ρ 12) in successive work cycles, but both individual amplifiers during each work cycle over a period of time at the same time as the full one - 21 209847/081 1 -21- $ 222138 Fluid pressure are applied and thereby Pressure fluctuations in the working medium can be avoided during its compression. 2o> Piston pressure booster according to claim 1, characterized in - that the control device contains two pressure control line pairs (9B »100; 102 ^ 104-), each with one end to one of the control valves (14 ·, 16) and with the other end to the cylinder (25 ». 24 ·) in the area of the larger surface section (26, 28) are connected, and thereby a first signal is generated ^. if each piston (18, 20) reaches a first predetermined position (116, 118) in which one of the control valves (14-, 16) is switched on, and the pressure stroke of the associated piston is initiated, and a second signal is generated when the second. Piston a second specified Position (114-120) reached in which it begins its pressure stroke and thus a considerable pressure stroke overlap is available. 3. Piston booster according to claim 1 or 2 /, characterized characterized in that the working fluid is one of the double-piston pressure booster with a pressure of more than 2000 kp / cm2 between the specified piston positions (116, 118 and 114-, .120) delivered liquid and the duration of the time segment is selected in such a way that the compression of the working medium in one of the individual amplifiers - 22 209847/0811 _ ₂₂ _ 2221338 ker is essentially ended before the pressure stroke of the second single booster is interrupted. 4- * piston pressure intensifier after one of the before _; he rgehenden · claims, characterized in that the working _T is medium water. 5 "piston pressure booster according to claim 4- ,. characterized,, that the water is supplied at a pressure of the order of 200 kp / cm2, with the formation of bubbles is kept very small. 209847/081 1 Blank page