DE1502149A1 - Hydraulic press - Google Patents

Description

The Cincinnati killing machine Co., Cincinnati, Ohio, V.St.A.

Hydraulic press

The invention relates to a hydraulic one Press.

Ia a hydraulic press, in it a pressure ram exerts a pressure on a workpiece, the size of the pressure exerted by the pressure ram & l3ich the surface of the plunger piston, that of the hydraulic fluid is exposed, multiplied by the size of the pressure of the fluid acting on the plunger λ. The pressure magnitude of the Flussi & Körc acting on the tappet piston becomes determined by the size of the V / id, it was built against the movement of the tappet, which occurs in the manufacture of the object. The resistance to the pressure ram movement becomes partial due to the resistance of the »/ Erkstückas against deformation and partly formed by a rick print, for example

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üby the liquid pressure in one behind the tool blank lying pressure chamber enclosed by a membrane. The greater the exposed to the hydraulic fluid Area, the greater the pressure exerted by the plunger. But the larger the pressure fluid exposed surface of the plunger piston, the greater the amount of fluid to be supplied to the piston, which is required to maintain a certain speed of the pressure ram. In other words, "Je the area exposed to the fluid pressure is larger, the slower the pressure surges! speed at a specific liquid supplied to the pressure tappet piston amount.

If the plunger piston certain area of a pump variable delivery liquid _& eführt, the plunger speed can be changed by changing the volumetric capacity of the pump. For example, with a variable capacity pump, the area of the plunger can be increased to increase the pressure applied to the plunger, and the volumetric capacity of the pump can be increased to maintain the speed of the plunger despite the change in area of the plunger. Pumps of variable power are in hydraulic presses with relatively moderately low

Printing (maximum pressure about 350 kg / cm) has been recovered,

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yet high pressure pumps are variable power

(about 700 kg / cm) cannot be produced at reasonable costs. In high-pressure systems, a pump with a constant length must therefore be used.

In a hyoraulic press, it is common to arrange different plunger pistons, the optional and sequentially connected to a pressure source of constant volume. With this conventional arrangement and with a pump with a constant flow rate, every change in the operating state that aims at increasing the piston areas to increase the pressure applied to the workpiece is inevitable result in a reduction in the ram speed.

A hygienic press is required created in which the exposed to the hydraulic fluid Area of the plunger piston can be changed and in the several pumps with constant flow rates individually or can be used together to create a greater number of operating accessories to create for the press. For each pressure level to be exerted, a special operating state is required, i.e. a certain pump or ai: .e Fuii.yerjKomDination works on ei :: e certain tappets piston uf lent or eiae bestiuji.te Combination of piston surfaces, which make the scauellstuü ^ - licne ütci? ele..eschwinaign.eit produced. I'll change them Printer orders. * Wanreac of a ForaiVor ^ to ^ efc, then

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deviating operating conditions are required in order to fastest possible ram speed during to achieve different sections of the drawing cycle. These operating states are described below as the most favorable Designated operating states. In contrast to the usual presses, it is surprisingly at increasing Pressure requirements sometimes advantageous, a smaller one Use piston area as the piston area that is used for smaller printing requirements is used. In the preferred Control devices are available with which the initial operating state can be selected can and then automatically during the Porm cycle lake Changes in the .üetriebsbedingungena cause so that during the fforrn cyclesee the face constantly the most favorable operating condition Has.

It is important that near the start of a company or step 3 on a workpiece - even if there is a change the piston surface takes place - the ram movement is maintained so that the workpiece o looks flawless and has a perfect surface. If the pressure ram is stopped before the end of the molding process, then the workpiece shows irregularities. In dar preferred Execution of the press shown here are included there are regulated valves that switch from one piston surface to another piston surface, so that the Possibility of stopping the ram is excluded.

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BATH ORIGINAL

With the invention is therefore a hydraulic Press created, which has an increased number of different operating states to the highest speed and To achieve press performance at a given pressure} which also includes automatic changes during the molding cycle when the pressure requirements of the Change the press to keep the press in the most favorable operating condition at the highest slide speed; in which furthermore the initial operating state is selected can, which automatically changes the operating status take place in order to keep the press in the most favorable operating condition for the highest impact! speed, and furthermore comprises an improved device which, without stopping the ram, changes or shifts one of the causes otößelflache on the other ctößelfläche.

The new hydraulic press for forming a die cut with one containing a liquid Pressure chamber and a flexible one located in the chamber Membrane that rests on one side of the workpiece, and with a pressure ram that is attached to the other during molding Side of the workpiece is characterized by the fact that the pressure ram is actuated by several cylinders, in which there are several pistons connected to the pressure tappet} that a large number of pumps with a constant delivery rate alternating amounts of liquid to the cylinders guide, and that working devices the liquid flow to the. Optionally regulate cylinders.

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In the drawings is

Fig. 1 is a partially sectioned partial view of a press according to the invention

Fig. 2 is a section along line 2-2 of the ^ ig.ii

3 shows a circuit diagram of the hydraulic flow system to regulate the worka of the pressure valve;

Fig. 4 is a table showing the various Operating states of the hydraulic press shows, namely with relative speeds of the plunger for the different operating conditions and with the cheapest Operating conditions of the press for various printing requirements, and

Fig. 5 is an electrical circuit diagram for the electrical control of the operation of the plunger System.

The hydraulic press (Fig.1) has an upright press frame 1o, with which by means of consoles a press bed 11 is connected, which carries the workpiece blank 13 to be formed or drawn. Sin with the press frame 1o above the press bed 11 connected Press head 14 slidably receives a sleeve 15. The sleeve 15 'which is flexible in its lower joint l membrane 16 trä ^ t, is on the press head 14 through on the Press frame seated motor (not shown) lowered in order to apply the membrane to the blank to be formed. • Operating fluid flows out of one on the press head

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attached storage container 19 with the valve 2oa open to that of the press head 14, the sleeve 15 and the Membrane 16 delimited chamber 17 »when the on the prease head located sleeve 15 before the start of the form before gear has been lowered. After the membrane 16 has placed itself on the blank 1J, the valve 2oa is closed. Then the valve 2ob is operated optionally, and high pressure liquid the chamber 17 is pressurized by means of the high pressure pump 21 which has a relief valve 21a

ρ
of 700 kg / cm is set, fed to the pressure

to increase ρ in the chamber 17 to, for example, 350 kg / cm.

Then the pressure ram 18 is raised to pull the workpiece. ^{When the pressure plunger 18 is} raised, the content of the chamber 19 decreases so that the pressure in the chamber increases. The pressure increase in the Κββμβτ 1? can be increased during drawing or molding by supplying additional liquid via valve 2ob or can be changed during molding by draining a limited amount of liquid via valve 2oa, after the molding process the sleeve 15 is open when valve 2oa, via which the liquid is sent to the reservoir is returned, lifted to take out the formed WerKstick.

The Prestenbett 11 euthM.lt two jjiit each other verbuudeue chambers or cylinders · 22 and. 2J who with their front sides lie against each other uoö a common one

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—Fr-

Have central axis A, which is also the central axis of the pressure plunger 18 . In the cylinders there is a drive element 24 which is connected to the pressure surge 18 at its upper end. The drive body 24 can be seen as consisting of two pistons, namely a lower piston 24a mounted in a sliding manner in the lower cylinder 22, which rests tightly against the cylinder wall 22a via an annular seal 25, and a piston 24D sliding in the upper cylinder 23 , which rests tightly against the cylinder wall 23a via a Bingäichtung 26.

jBin the eating bed 11 penetrating passage 3o forms a fluid line which is in constant communication with the lower find of the piston 24a. A passage 31 passing through the press bed 11 forms a fluid line which is in constant communication with the lower part of the piston 24b. An annular groove 32 in the upper part of the cylinder 23 is in constant communication with the storage container 33 via a line 34 passing through the feed bed 11.

The pressure ram 18 is lifted when pressure fluid is fed to the lower part of the cylinder 22 via the line J> o and acts on the lower part of the piston 24a, and / or when pressure fluid passes through the line. 31 is fed to the lower end of the piston 24b. Two safety valves located in the drive body 24 set the drive body when it reaches its upper limit of movement

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quiet. The first usually closed safety valve 35 is via the passage 36 with the lower Ond of the Cylinder 22 connected, and the second for ordinary closed safety valve 37 is via the passage 38 connected to the lower end of the cylinder 23. Both valves are when applying the valve rods 35a and 37a open to the upper And wall of the cylinder 23, so that the passages 36 and 38 via the passage 39, annular groove 32 and line 34 with the reservoir 33 in connection stand.

The pressure plunger 18 is by means of a fixed ^ Piston 45 lowered, which is located in a cylinder 46 of the drive body 24 and which is through a piston rod 47 connected to the lower edge of the press bed 11 is. The cylinder space 46 located above the piston 45 is via the line 48, line 39, an annular groove 32 and line 34 are constantly connected to the storage container 33. The cylinder space below the piston 45 baficd 46 is penetrating through the piston rod 47 via eiue Line 5 ° connected to valve 49. The valve 49 is at a standstill with the pressure line 51 and with the return line 52 in Link. When the solenoid SOL1 of this valve is switched on and the valve pin 53 is to the right of the is in the position shown in Fig. 1, the line is 5o with de; Pressure line 51 connected and is from the return line 52 switched off, so that in the one below the

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There is a pressure present in the cylinder space 46 located in the fixed piston 45, which lowers the drive body 24 and the pressure plunger 18. The solenoid SOL 1 is switched off as soon as pressure fluid is either via the line 3o to the cylinder 2 o or via the line 31 to the cylinder 2? J3 ^; to be led. When the solenoid SOL 1 is switched on, the spring 54 moves the valve piston 53 to the left into the in fiß. 1, the line 5o is connected to the return line 52 and the line 50 is also separated from the pressure line 51 so that there is no pressure in the cylinder space 46 below the piston 45 and the drive body 24 and the pressure tappet 18 are lifted can.

In the specific embodiment shown, the useful area A1 of the drive body 24, which is exposed to the pressure prevailing in the cylinder 22, or more precisely The useful area A1 of the piston 24a, which is exposed to the pressure prevailing in the cylinder 22, is equal to (D1) ² _ Ύ (D2) ² , where D1 is the diameter of the

Pistons 24a and D2 the diameter of the piston rod 47 is. The useful area A2 of the drive body 24, dia the im Cylinder 23 is exposed to the prevailing pressure, or more precisely The usable area A2 of the piston 24b, the dam in the cylinder iod ei? 23

is exposed to the prevailing pressure is the same

I * ( ^D 3) ** ^(D1) , where D? the through-

4 4

diameter of the piston 24b is.

When manufacturing pieces of material from blanks 13, the most favorable pressure to be fed to the hammer 17 depends on various factories, for example on the shape of the piece of value and the thickness of the piece of work piece. For most shapes, the best results are obtained when the bridge prevailing in the chamber 17 increases, when the shape of the workpieces changes when the pressure ram 18 is lifted. During all molding processes, the flexible membrane creates a downward pressure due to the pressure in the chamber 17. exerts on the pressure ram, a resistance to the upward movement of the Druckstokeis, au Dall on the plunger so & Roiter üui würtsdrucK from _t ed to be t, that the mentioned resistance u overcome; jd the Auc.vartsbewegung of the pressure plunger upright erhalteu λίγο. Since with many workpieces the pressure in the chamber 17 increases during the molding process, the resistance against the upward movement of the pressure increases during the molding process; ice cream.

Especially when producing a-ar larger It is desirable to have a lot of .Verkstückeu, every single one xv to iormeu in the shortest possible time. Read requires

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that which can be achieved with the available force Maximum speed of the pressure ram as long as this speed is not the permissible forming speed of the metal to be drawn. With a Zihpresae, which has a pressure source of practically feasible size, If the total force available is used, a pressure surge speed is not achieved, the highest permissible pulling speed of the Metal used in the usual drawing process.

In the case of a hydraulic seizure with a plunger drive body that is moved by a motor-driven pump, the power output of the motor is proportional to the product of the »flow rate Q of the liquid conveyed by the pump and the liquid P. The pressure required to move the pressure plunger becomes determined by the resistance to the pressure plunger movement and the usable surface of the otößelkolbena or otößelkolbena that is exposed to the hydraulic fluid. It is known to use a larger number of tappet pistons, & o that different usable areas can be used by optionally supplying the pressure fluid to one piston or several pistons. If, for example, ■ three different piston areas are available, then xvann with a pump with a constant delivery rate of the el at three different speeds

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"be moved because of a specific, vender pump flow velocity generated the velocity of the pressure tappet is inversely proportional to that of the hydraulic fluid exposed plunger surface is. With this arrangement, the flow rate Q is from the The pump is the same under all working conditions, and the pressure P of the liquid changes for any given one Effective piston area with the resistance to the slide movement.

At the n ^ ueri hydraulic press will be more extensive operating conditions of the press through use two pumps maintain the same delivery rate, and there are devices that change the operating state of the press to operate the press plus ta cd to keep the greatest possible Best speed of rebound :. niardurch is from achieved even the fastest possible molding cycle.

Fig. J shows two pumps in the flow channel 60.61 constant flow rate. The pump 6o is eica ■! Low-pressure pump with a high delivery rate, which operates at an extra pressure of, for example, 280 kg / 'cm is set and the has a constant flow rate of 75.6 l / min.

The pump 61 is a high-pressure pump with a low delivery rate,

ρ which is set to a maximum pressure of 700 kg / cm and has a constant flow rate of 37.8 l / län. Both pumps 6o, 61 are driven by a power source comprising a einfacner Ji ¹ IeKtromotor or iw

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can be grupps. In any case, the entire capacity is available the source of power in the required manner of the one or the other pump or "both pumps.

The high pressure pump 61 also sucks in liquid Reservoir 33 and promotes the liquidity under pressure to pressure line 51 · Bin safety valve 63 iat ao

set to open at 700 kg / cm to the Liquid back to the storage container 33 ζ never it s,

so that a pressure re-development of over 700 kg / cm in the pressure line 51 is prevented. The low-pressure pump 6o is connected to the pressure line 51 via a relief valve 64 and a Check valve 65 connected. The relief valve 64 remains closed so that the entire output of the pump is fed to the pressure line 51 until the pressure in

2 of the pressure line 51 reaches the fleas of 280 kg / cm, The relief valve 64 then opens to reduce the power the pump 6o at outside air pressure to the storage tank. The relief valve or drain valve, which is a commercially available valve, has a plunger with a piston 67 «attached to it, the

tion 51 existing pressure less than 280 kg / cm, then holds the spring 68, the poppet valve 69 closed and the Ventilplungsr 66 is located in the position shown. to At this point, liquid flows out of the pressure side of the pump 6o via the relief valve and the check valve 65 however, no liquid flows over to the pressure line 51 '

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the branch line 7o containing the throttle 71, so that the pressures present on both sides of the piston 67 are equal. The pressure prevailing in line 7o. exposed area of the piston 67 is slightly larger than that area of the piston 67, which exerts the delivery pressure pump 6o is exposed, so that the plunger 66 is held in the illustrated left position in which the connected to the reservoir from lan. opening 64a is blocked. If the pressure prevailing in the line 51 reaches the pressure value 280 kg / cm, then the plunger 72, one end of which is exposed to the pressure prevailing in the line 51, overcomes the pressure of the spring 68, so that the poppet valve 69 opens and a Fluid- . keitööiirom in line 7o. This liquid flow flows past the poppet valve 69 via the hunger 72+, via the plunger 66 and the opening 64a to the storage container. As a result of the throttle 71 in the pipe 7o the pressure falls behind the piston 67, and the plunger 6b moves to the right thereby opening a passage and but the opening 64 a from the pressure side of the pump 6o to the reservoir. The check valve 65 prevents the loss of fluid to the storage container from the pressure line 51 when the load relief valve 64 is open.

The pressure line 51 is with the inlet ports 75 and 76 of the two valves V1 and V2 consumed and stent also via the check valves 77 and 78 with the

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JBinl ate off use 79 or 8o of the work aventil e 81 or 82 in conjunction. The outlet opening 83 is connected to a working opening 84 of the valve a V1 and the outlet opening 85 of the valve a 82 is connected to a working opening 86 of the valve a V2.

The outlet opening 87 dea Refcelvehtilea 01 is connected to the Hegel opening 90 dea valveea 81 via the Hückachlagventil 88 and a non-return valve bypassing the narrowed passage 89, and breathes via the nonreturn valve 91 and a nonreturn valve bypassing the narrowed passage 92 with an opening 93 of the valve V1 in Link. üie Aualaßöffnuqg 94 of a Regelventilea 02 iat an Rüokachlagventil 95 UCD a daa Bückschlagventil immediate constricted passage 96 with the control port 97 of the Ventilea 82 weifcunlen, and is about daa check valve 98 and a the Bückschlagventil immediate constricted passage 99 with an opening 1oo dea valve V2 in Link. The control valve 01 has a solenoid S0L2, since when switched on, the valve plunger 1o1 moves to the left (as seen in FIG. 3) in order to connect a pilot pressure line I03 to the outlet 87. When the oleuoid SOL 2 is switched off, the plunger Ιοί is moved to the right by the spring 1o1a in order to connect the outlet opening 87 to a return line 1o2. The control valve 02 has a solenoid 0OL3, and the valve plunger 1o4 when it is switched on

6AD OBlGlNAL

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moved to the left (seen in Fig. 3) to the pilot pressure line I03 to connect to the outlet opening 94. When the solenoid SOL3 is switched off, the valve coupling is activated 1o4 moved to the right by the spring 1o4a to the outlet opening 94 · to be connected to the return line, 1o2 pilot pressure pump provided with a relief valve 1o7 1o6 conveys liquid from the reservoir 33 to the pilot pressure line 1o3 with a relatively

2 low pressure of for example 35 kg / cm.

The valves V1 and V2 have outlet lines 115 and 116 (Pig.2), which are connected to the reservoir 33 via lines 117 and 118, respectively. The valve V1 has a cylinder opening 119 connected to the line J> o through which the liquid flows to the chamber 22 and out of the chamber 22, and the valve V2 has a cylinder opening 120 connected to the line 3I, via which the liquid flows to the chamber 23 and flows out of the chamber 23. The valves V1 and V2 have the same design. Each valve has a valve piston 121 acted upon by a spring 122 which, in the position shown, shuts off the cylinder openings (119, 12o) from the outlet openings (11o, 117). In

a

second valve piston 123, which is acted upon by a liner spring 124 and which is shown in FIG Position the fiinlaßöffnungen (75,76) blocks with the pressure line 51 are connected. Every valve has one

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sleeve 125 sliding in the valve, which is supported by a spring 126 located between the sleeve and valve piston 121 from the Valve piston 121 is pushed away. Each valve also has a cylinder 127, one of which ends with the working opening (84, 86) and its other sins with the ^ ual aß opening (115,166) connected. Sin in the cylinder 127 existing piston 128 is connected to a piston rod 129 sliding in the sleeve 125, which is attached to the Valve piston 123 and the inlet openings (75,76) holds closed when the piston 127 has been pushed toward the inner end of the cylinder 127 by a ErucK at work. The piston rod 129 has a passage 130 that opens the work opening (84.86) connects to the outlet port (115 »116) when the sleeve 125 is pulled out of the valve piston in the queue shown.

The Hegel valves 01 and G2 are either both switched on at the same time to block the flow of pressure fluid to both cylinders 22 or 2J> , or one of these Hegel valves is switched on and the other is switched off to block the flow of fluid to one cylinder, or both valves are switched off so that liquid can flow to both. When the solenoids 60L2 and are switched on, there is a pilot pressure at the openings 90 and 97 of the working valves 81 and 82. The work openings 84 and 86 of the valves V1 and V2 are therefore connected to the pressure line 51 via the working valves 81, 82.

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Since the pistons 128 present in the valves V1, V2 are larger than the area of the valve pistons 123 exposed to the pressure in the line 51, the valve pistons 123 are moved by the piston rods 129 to open the openings 75 »76 due to the pressure at the openings 84 , 86 existing pressure of the main pressure line 5 ^ to close. At the same time Vorateuerdruck is at the openings 93 »1oo with the existing on the outer end of the sleeves 125 chambers 135 in connection to the Httlaen 125 in abutting contact with the valve piston stop 121 SU, laundri the valve piston 121 are lifted from their öitzen, openings around the cylinder 119,12o to connect to the outlet openings 115,116.

The solenoid 80L2 of the Hegel valve C1 becomes switched off, mn a hydraulic fluid astro m to the cylinder 22 to generate. When the solenoid is switched off, the pilot pressure is applied from the opening 9o of the valve fabric 81 and the opening 93 dea valve V1 removed and these openings «Earth with the return line, 1o2 connected. As soon as the pilot pressure is removed from the opening 9o, τ follows a movement of the valve piston 81a of the valve 81 by the spring 81b to the position shown in Fig. 3 to the supply of the pressure fluid to the opening 84 of the valve To interrupt V1. Since the pressure drop across the port 93 of the valve V1 is delayed by the throttle 92a present in the line 92, the sleeve I25 of the valve reverses V1 later to the position shown in Fig. 2 zuück, so

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that the valve piston 121 closes. This will the passage 130 of the valve V1 to the outlet port II5 opened and as a result the opening 84 with the Bückführleitung 117 connected. The piston rod 129 is withdrawn as a result and the fluid pressure The valve piston 123 opens in the pressure line 51.

Should the effect of the liquid pressure are changed from the area A1 to the area A2, then the solenoid S0L2 of the control valve 01 is switched on and the solenoid SOL3 of the bell valve becomes C2 switched off at the same time. It is important that the pressure ram move without interruption during this area change moved, because by stopping the pressure la would repel ♦ " and e rl i have an irregularity in the surface of the too forming workpiece occurs. When switching on the Solenoid S0L2 is the pilot pressure line I03 with the Opening 87 of the Begel valve 01 connected and the Vorateuerdruck is immediately applied to the opening 93 of the valve V1. At the same time, the opening 94 of the Begel valve C3 is connected to the return line 1o2 and the control pressure is immediately released from the opening .97 of the valve 82 removed so that the valve piston 82a moves under the pressure of the spring 82b to the right and the Supply of pressure fluid from the opening 86 of the valve V2 locks. Since the pressure increase at the Begel opening 90 of the valve 81 through the throttle present in the passage 89 89a is slowed down, the pressure from the pressure line is reduced

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51 later applied to the opening 84 of the valve a V1. The generated by daa .Nadelventil 89a in line 89 However, restriction is greater than the restriction created by needle valve 99a in line 99, so that as a result the pressure is removed from the opening 1oo of the valve V2 after the pressure is applied to the opening 93 of the Valve V1 has occurred and after the pressure is off the pressure line 51 from the opening 86 of the valve V2 is blocked, but before the pressure of the pressure line occurs at the inlet port 84 of the valve V1. Sa finds alao folger.de Movement sequence instead: First the HüL-e 125 of the valve V1 in contact with the valve piston 121 advanced, however, the valve piston 121 remains closed because of the pressure on the opposite Oeite of the valve piston 121, which is equal to the pressure in the Chamber 22 is holding the valve piston 121 closed. At the same time the opening 85 of the control valve a 82 blocked in order to block the pressure line 51 from the opening 86 of the valve V2, but the piston rod 129 of the valve V2 is only withdrawn when the opening 86 of the valve V2 is connected to the outlet. Then the pressure drops at the opening 1oo, so that the The sleeve 125 of the valve V.2 is returned by the spring 126 and the opening 86 to the outlet is opened, furthermore the valve piston 121 closes and the Valve piston 123 of Ventilea V2 under the pressure of in the line 51 existing hydraulic fluid opens.

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Too diesel? Time so pressure fluid is supplied to both the area Δ1 and the area A2, so that the upward movement of the piston body 24 is continued. As soon as a pressure build-up finally takes place at the control opening 9o * of the valve 81 and the valve piston 81a is moved to the right, pressure fluid is supplied to the opening 84 of the valve a V1 in order to close the opening 75. When the opening 75 is closed, the upward movement of the piston body 24 reduces the pressure in the cylinder 22 so that the valve piston 121 of the valve V1 can open and connect the chamber 22 to the outlet, via line 3o past the valve body piston 121 to the outlet opening II5. The throttling generated by the needle valve 96a in the line 96 is greater than the restriction produced by the needle valve 92a in the line 92, so that a switching from the area Δ2 to the area Al in eggs same as erf olger <can be, like the switching of the area A1 on the area A2.

To illustrate the mode of operation of the new press, it is assumed that the usable area Δ1 of the piston 24a, which is exposed to the pressure in the cylinder 22, is 645 Q » ² " and that the usable area A2 of the piston 24b, which is exposed to the pressure in the cylinder 23 , 1290 is about ^2. Let it also be assumed that the pump 60 conveys a constant volume Q2 of 77.4 1 / lfia

BATH

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of 280 kg / cm is set, ao that the discharge

p valve 64 · works at a bridge of 280 kg / cm. It is also assumed that the pump 61 conveys and opens a constant liquid volume Q1 of 38.7 l / min

ρ
a maximum pressure of 700 kg / cm is set.

With these parameters and with a pressure of up to

2
EU 280 kg / cm, the combined liquid volumes Q1 and Q2 of both pumps can only be supplied to area A1 in order to generate a pressure of 180,000 kg at 280 kg / cm, or they could only be supplied to area A2

2
be to generate a pressure of 360,000 kg at 280 kg / cm, or can simultaneously the areas A1 and A2

2 BU to generate a pressure of 540,000 kg at 280 kg / cm. Sa should be noted, however, that with a certain inflow, for example 116 l / min, the area A1 generates a faster pressure surge el speed than the same inflow to a larger area. With the parameters given for explanatory purposes and with an inflow of 116 l ^ min, the impact el speed S when using the area A1 is about 176 cm / min, which is twice the ram speed when using the area A2 and three times the speed if the areas AJ [ and A2 1st.'Ss are used at the same time, it should also be pointed out that the force that is used to produce a ram pressure of 160,000 kg and ei.je

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To achieve ram speed S, equal to the force is that used to be when used alone the area A2 has a tappet pressure of 360,000 kg and a To achieve thrust el speed of S / ^ 2, or at simultaneous use of areas A1 and A2. Ram pressure of 540,000 kg and a ram speed of S / 3 to achieve. (For its intended purpose en aei aieae force as the maximum available force look).

At pressures above 280 kg / cm, the pump is 60 at Outside air pressure to the storage tank emptied and di · in. the pressure fluid available to the system becomes limited to the flow rate Q1 of the pump 61, the reading of which is 38.7 1 / llin. As a result, the speed is of the plunger when using the given area or combination of areas is equal to one third of the Speed that corresponds to the flow is 116 l / min was achieved. However, since a higher pressure, namely bia

2
up to 700 kg / cm can be used, larger prints can also be achieved. If only the area A1 is used, the plunger can exert a pressure. exercise from 450,000 kg at 700 kg / cm. When using the area A2 alone, the ram can exert a pressure of ^ OO 000 kg at 700 kg / cm ² . When surfaces A1 and A2 are used at the same time, the push rod can exert a pressure of 1,350,000 kg at 700 kg / cm ² . The current flowing at maximum pressure (700 kg / cm ² ) in

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each of these three operating states is used, iat the same, but smaller than the current that eiuem

ρ
Maximum pressure (280 kg / cm) is consumed when both pumps are working.

A tiny pump becomes more consistent Delivery rate in connection with several tappet piston surfaces is used and if the highest working speed of the pressure ram is achieved, then work begins with the smallest possible area that is required, to achieve the desired pressure. If the printer folder nose rises during the dragging process, then the Areas increases progressively and must speed of the plunger are constantly reduced. When using two pumps with a constant flow rate, however, and with several areas it is not always necessary to use a larger area and a lower speed to switch when the pressure is increased. Surprisingly, it is sometimes possible to use a smaller area to switch and at a higher speed work as if the surface remained unchanged became.

This process is shown in Fig. 4, in the two operating state β for the area A1 alone, for the area A2 alone and jointly for the areas A1 and A2 are shown with both pumps at or below

ρ
280 kg / cm work or the pump 61 alone at over

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.26-15021

ρ 2

280 kg / cm works. Fig. 4 shows that below 280 kg / cm the highest speed S achievable if both Pumps only work on one surface A1. lin However, changing the operating status is necessary when working necessary if the required pressure is over 180,000 kg increases. Either the pump 6o must be switched off, so that a higher pressure is made possible, or if the duck should be kept below 280 kg / cm in order to ensure the use nag of the pump 6o must be maintained, the area of de * Area A1 can be switched to area A2. Through the first ülernative will be the speed of the rump S reduced to S / 2. The second alternative would the speed of the ütffišel reduced to only S / 2 become what is preferred. The more favorable operating state for each pressure range is shown in dotted lines in FIG. 4, around the area or combination of areas used and to show the pump or combination of pumps used with the highest possible slide speed is obtained.

Between 360,000 kg and 540,000 kg the Areas Δ1 plus A2 preferred, with both pumps workinga, uod at 540,000 kg pressure the maximum pressure is achieved. Surprisingly, however, between 540,000 kg and the like 900,000 kg, a smaller area A2 can be twisted, as with this smaller area has a higher speed s / 6

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can be achieved as the highest speed S / 9 that when using the combined areas A1, A2 is achievable.

Although FIG. 4 shows five most favorable operating states for each different pressure range, it is seldom that more than three operating states are required in the manufacture of a certain vaporizer. In all drawing processes, the pressure requirement increases during the molding process. Control devices are provided in order to automatically carry out two changes of the operating states based on the pressure requirement, with each change from the most favorable operating state in one pressure range to the most favorable operating state for the next higher pressure range when the pressure reaches the highest value of the lower pressure range. The preate can be set up so that the drawing process takes place in any of the three operating states which are most favorable for the three lower pressure ranges:; d, and the operating states are then automatically changed during each drawing process and gradually to the two most favorable operating states for the two successive higher pressure bars led by oak.

In Fig. 3, four pressure switches 1PS, 2PS ₁ 3Pß and 4PS are connected to the pressure line 51. In order to explain a certain operating cycle, it is assumed that the pressure switches 1Pq and 3Ρ · -> for usually open

909842/0503

Are switches that close when the pressure in line 51 ^{rises to 280 kg / cm 2} because the pressure switch 2PS is a usually closed switch that opens when the pressure in line 51 rises to .245 kg / cm increases; and that the pressure switch 4PS is a normally open switch which closes when the pressure in the line 51 reaches ^{700 kg / cm 2.} As FIG. 5 shows, a current source 140 is applied to the mains conductors 141 and 142 when the switch 143 is closed. Relay 5GB connected to conductors 141 and 142 is turned on only when switch 144 is closed to close normally open contacts 6GR1, 6CB2 and 6GB5 and to open normally closed contacts 6CH4, 6GR5, 60R6 and 6CR7. The relay 10B, which is between the conductors 141,142 in series with the pressure switch 1B3 and the normally closed contacts 6CB4 of the relay 6OB, is switched on when the switch is open and the pressure in the line 51 has a pressure of

280 kg / cm reached. Ordinary in its purest form, the open ones lie Contacts 1CB1 of relay 1CB parallel to the drum switch 1PS to hold relay 1CB ready until contacts 6CB4 open when switch 144 closes. That Relay 2CR is connected to the chase conductors 141,142 in series with the pressure switch 2PS, the normally open contacts 1CR2 from relay 1CR and the normally closed contacts 6CR5 from relay 6CR. 'Airä atjgenoirimen that the

909842/0503

Switch! " 144 is open then relay 2CR will initially only turned on after the relay 1GR turned on has been and if the pressure in the line 51 is below

245 feg / cm. The open contacts 2CB1 of relay 2CR are parallel to switch 2PS and contacts 1CH2 to hold relay 2CR until the Switch 144 is closed. The 3CR relay is connected to the mains conductors 141,142 in series with the 3PS pressure switch, the normally open contacts 2CR2 of relay 2CR and the normally closed contacts 6CR6 of Relay 6CR switched. With switch 144 open, relay JCR is only turned on after relay 2CR is turned on has been and then the pressure in the line 51 reaches the value of 280 kg / cm. Usually open contacts 3CR1 of relay 3CR are parallel to the contacts 2CR2 and the switch 3PS to the relay 3CR until switch 144 is closed. The relay 7CH is in parallel with conductors 141,142 in Series connected with pressure switch 4PS and contacts 6CR7 of relay 6CR. When switch 144 is open the relay 7GR switched on when the pressure in the line

2
tion 51 reaches the value of 700 kg / cm. The normally open contacts 7CR1 of relay 7CR are parallel to switch 4PS in order to include relay 7CR ao long until switch 144 is closed.

909842/0501

Sa it is assumed that a Werkatückzuachnitt 13 is to be produced at a pressure which, while the division constantly increases, with the initial pressure in the Chamber 17 exerts a pressure of 225,000 kg, which is ben of the plunger 18 counteracts and the aich on one in the chamber 17 existing 3nddruck increased against the plunger 18 exerts a pressure of 635,000 kg. Fig. 4 shows that · the initial operating state of the press the Use of both pumps 60,61 together with the tappet piston surface A2 includes. With an initial form pressure of 2250OO

ρ kg and a usable area A2 of 1290 cm, the starting

ο pressure in the pressure line 51 about 175 kg / cm. If the pressure requirement is 360,000 kg and the pressure in the line 51 reaches the value 280 kg / cm, as FIG. 4 shows, the pressure on both area A1 and on surface

A2 brought into effect. At 1935 om piston usable area

Instead of approx. 1290 usable piston area, the pressure drops in

^{in line 51 when changing to approximately 187 kg / cm 2} , but then rises again until the pressure demand is 540,000 kg and the pressure in line 51 is again .280 kg / cm 2. When a pressure of 540,000 kg is required, as shown in FIG. 4, the pressure is removed from the area A1 and the pressure pump 60 for low pressure is switched off et al. After this change in the operating state, the effective area of the piston is 1290 cm and the pressure in the line 51 is 42D kg / approx with a recovery of 540,000 kg. The pressure in line 51 then rises

9011427OiOl

a final value of 675 OCXD kg for a pressure delivery

ρ
and a pressure of 525 kg / cm.

The operator chooses the correct starting surface, to get the press in the correct start & s operating condition and then the prease changes in time and automatically the operating statuses Form cycle aes. To select the surface A2, the closes Operator the switch SA2 and leaves the switch SA1 and SA12 open. The switch 144 is also opened. The solenoid SOL2, which is between the mains conductors 141 and 142 in series with the usually closed Contacts 70B2 from Beiais 7CB can close when closing. of the switch SL2 are switched on via the usually closed contacts 1CB5 from Beiais 1CB or via the normally open contacts 3CB3 of Belaia 3CH. The solenoid S0L2 is also between the Mains ladders 141 and 142 in a row with German usually open contacts 6CB3 of the case 6CB, so that the solenoid S0L2 is turned on as soon as the switch 144 closes will. Another power supply to turn on the solenoid SOL2, either via the contacts SAIb of the switch SA1 or via the contacts SA12 and the normally open contacts 1CB4 of the accessory 1CB and the usual door ^ closed .. contacts 2CB2 from Beiais 3CB runs, is during a form flow that begins with the area A2, not effective because both ochaltor SA1 and SA12 are open.

909842/0503

The solenoid SOLJ is connected between the power conductors 141 and 142 via the contacts SA1a of switch SA1 and normally closed contacts 1CE3 of legs 1CB, but is not turned on through this flow path when the molding cycle with the area A2 starts, since the switch SA1 is left open. However, the normally open contacts 6CB2 are connected to the contacts SA1a and 1CE3 so that the solenoid SOL3 is turned on when the switch 144 is closed.

With the switch closed 143 and SA2 and with open switches SA ¹ I, SA12 and 144, the solenoid S0L2 is turned on at the beginning of the molding cycle, around the conduit 51 to block the area A1, and the solenoid S0L3 is turned off to the pressure line 51 ISSI * to join the area A2. At an initial pressure in line 51 of 175 kg / cm, the pressure switches 1PS, 3PS and 4PS are opened, and the Beiais 1CB, 3CB and 7CB are therefore switched off. The pressure switch 2PS is closed, but the contacts 1CB2 of Beiais 1CB remain open, so that the Beiais 2CB is also switched off. If the pressure requirement reaches 360,000 kg and is therefore the pressure in the line

51 about 280 kg / cm, then the pressure switches 1PS and 3PS close and the Beiais 1CB is switched on. The Beiais 2C-B and ate consequently the Beiais 3CB not be turned on at this time because "is open, the pressure switch 2PS at 245 kg / cm ^2.

9098A2 / 0503

When you switch on Helaia ICH, it will oolenoid S0L2 switched off and α ie area A1 becomes Pressure line 51 opened to open up the piston surface

Increase 1935 cm. Hierdui'cü. the pressure drops in the line 51 below 245 kg / cm '', and the relay 2CR is switched on

the pressure in line 51 of Oji ^{1-Betriebszusta} .des falls due to the change opens UICH aer container so the Heiais 3or AAII to cii ^ s. ^ r ^ eit Not-c eingeacnaltet wira. If, however, the printer force increases, then the pressure in line 51 rises and then 3Bi closes and switches on relay 3CR, ¹ JVQuα the pressure 540,000 kg

2 and the pressure in the line is 'd'öO Kg / cm.

At this time the solenoid 30L2 is turned on again, to block the area A1 against the pressure line 51.

In this ..echs <L the oper. b ^ zuatandes the pressure in line 51 sprays to 420 kg / cm and rises until the molding cycle ends i.it. When the workpiece is fully formed, the switch 144 is closed to switch on the heater, so that both solenoids 30L2 and UL3 are switched on at this time and both surfaces a1 and a2 are shut off from the pressure line. At the same time, the heaters 1GR, 2CR and 2CR are switched off, so that the dtromkreia is provided for a subsequent form cycle. When relay 6CR is switched on, the dolenoid SOL1 switches on to lower the plunger so that the stick can be removed.

909842/0503

λθω.ϊι example Drucii promotion for a Formzyitlua at a ive angsdruck of 112 kg 500 begins and rises to rjinen tfnddrucK of 450,000 Kfe, then the switch is first gaschlosaen SA1 and a IU switch 144, SA2 and 3A12 -Be open gelaasen, ao.) First the solenoid S0L3 is switched on in order to block the area A2 against the pressure line 51. The cycle therefore only begins with the surface A1. Sr at a ine αϊ pressure of Löü 000 kg, the pressure in the line 5'1 first reaches the value of

ρ
280 'J ^ g /' cm and the EeIais ICH is switched on to open the contacts 1GRJ and cut the junction 1GB4, then the solenoid S0L3 is switched off, uia the area A2 -ur pressure line 51 to open, and that Solenoid S0L2 is ο lngeschaltat in order to block the area ΑΊ of the pressure line 51 iD. This causes the pressure in the pressure pipe

üimg 51 · -enn a ns cn the pressure as shown at 280 kg / cm rises to switch on the relay 3CR, the contacts will 3CR2 opened to turn off the solenoid S0L2 and the area a1 to open again to line 51.

For example, does a ForiiiZ./Klus require a Initially from 45v. 000 kg, with a final pressure of I 350,000 kg increases, then switch 3A12 initially closed and switches SA1 and SA2 are left open. Therefore, Aeder becomes the solenoid S0L2 nor the solenoid 30L3 switched on and both surfaces A1 and A2 become Pressure line 51 open, armranges at a pressure of

909842/0503

540 000 kg de: Pressure in the pressure line 51 adorns

280 kg / cm and iet the Beiais 1CB switched on to the Contacts 1CB4 close then solenoid 30L2 closed, and blocks the area Δ1 from the pressure line 51 from. At the same time, the low pressure pump 6o switched off. With this change in the employment relationship a

ρ the pressure in the line 5 ^ jumps immediately to 420 kg / cm and then increases when the pressure is 900,000

2?

kg fc.uf 700 kg / cm. At a pressure of 700 kg / cm in the Pressure line 51 closes the pressure switch 4PS and maintains the relay 7CB. Open contacts 7CR2 itself, the solenoid S0L2 is switched off and the piston surface A1 stands for pressure line 51 oifen.

Although the pressure in the pressure line 51 immediately ^{drops to approximately 466 kg / cm 2} , the solenoid SOL2 remains switched off until the molding cycle is completed. The switch 144 is then closed.

9098A2 / 0503

Claims (8)

Claims 1. Hydraulic press for forming a tool blanks with a liquid-containing pressure chamber and a flexible membrane located in the chamber, which rests on one part of the workpiece, and with a .Druckstößel, which rests on the other side of the work piece when forming , characterized in that the pressure ram (18) is actuated by a plurality of cylinders (22, 23) in which there are several pistons (24a, 24b) vouched for with the pressure ram (18); that a large number of pumps (60, 61) with constant delivery capacity alternately direct liquid to the cylinders, and that working devices (SA1, SA2, SA12, O1-V1, C2-V2) optionally regulate the flow of liquid to the cylinders. 2. Press according to claim 1, characterized in that the large number of rags are more constant Delivery rate consists of two i-umpen (60,61), which over a pressure line (51) are connected to the cylinders, and then · the working device removes the flow of liquid the pressure line iu each. Cylinder optionally interrupts. 9098A2 / 0503 3. Press according to claim 2, characterized in that that the pumps have a constant delivery rate from a low-pressure pump (6o) and a high-pressure pump (61 χ exist; that a device (64-) on the in the pressure line (51) responds and the low pressure pump (6o) switches off from the pressure line (51), and that the ikrbeitsvorrichtung the pressure line (51) optionally with one or the other cylinder or connects both cylinders. 4. Press according to claim 3> characterized in that the cylinders (22,23) innahalb of the press bed (11) are arranged} that a piston body (24) is connected to the plunger (18) Cylinders located piston (24a, 24b) forms; that the low pressure pump (6o) has a relief valve (64) is connected to the pressure line (51), and that the working device z ^ ei valves (V1, V2) which arranged between the pressure line (51) and the cylinders are. 5. Press according to claim 2, 3 or 4, characterized in that the pistons are several different, large Have usable areas (A1, A2) which are exposed to the pressure from the pressure line (51), and that a device (1PS-4PS, C1-V1, C2-V2) related to the print in this print 909842/0503 line that changes the usable area of the pistons, which is exposed to the pressure prevailing in this pressure line. 6. Press according to claim 5> characterized in that the on the in the pressure line (51) If there is a pressure-exerting device (1P8-4PS, G1-V1, iJ2-V2) consequently those connected to the pressure line Cylinder changes, depending on the size of the pressure present in this pressure line. 7- Press according to claim 6, characterized in that the working device has switches (SA1, SA2, SA12) which connect one or the other or both cylinders (22,2J) to the pressure line (51) to achieve the highest pressure shock el ge speed against the λώ £ a ng swid result against the slide movement, and that the sequence change device maintains the highest slide speed for any given resistance value against slide movement. 8. Press according to claim 7 »characterized in that that the pressure in the pressure line increases when the resistance to pressure ram movement elevated. 909842/0503 9 · Press according to claims 4 to 8, characterized characterized in that the two valves (V1, V2) connect the • rate cylinder to the pressure line (51), eh · the second cylinder disconnected from the pressure line when a change from the second cylinder to the first cylinder takes place during the molding process. 909842/0503 Blank page