DE1577264A1 - Press - Google Patents

Description

Applicant;

L · · Schüler GnbH Stuttgart, February 21, 1966

732 Göppinpen ρ 1370 I / O

Bahnhofstrasse

Press

The invention also relates to a press in which the » Preasenhouptwellt by ink venting one of compressed air act on the cylinder can be braked and ddt Brtasiiag in emergencies with a brake »« o ** nt takes place, the bigger one

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all the braking force normally used is.

In the case of a press, the torque is on the one hand as good as possible be high so that the overrun travel is as small as possible when braking in emergencies (emergency stop). .If however the braking torque increases very quickly and is very large during braking, so the press housing by the hard burn of the. moving hatred see below vibrations excited. Particularly in the case of presses with a top drive, vibrations with a disruptive amount can occur Amplitude occur »and prevent these vibrations, Is it known, la normal case (normality), if the shortest possible overtravel is not decisive Brake off with a smaller brake monent, like that that no vibrations of the press housing occur. The solution to this problem is difficult above all because a degree of security is required for the Kothalt, which is far above that otherwise usual with v / Erkseugmaechliien Degree of security lies. This means that various designs are ruled out from the outset. In known presses the problem was solved by the fact that at »Norwalhalt the whole brake housing is relatively sub press housing rotates with a braking torque that is less than that

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Braking torque when stopping. In the case of an emergency stop, however, that is Brake housing held in place and the brake housing in the brake housing self-arranged brake with iron «proportionate high braking torque takes effect.

The known construction requires a very large one Effort and is therefore very expensive. The invention is based on the object of the different Breosmomente to be realized with emergency stop and normal stop by means that are structurally simpler, but without that the level of security of the arrangement is reduced

This object is achieved according to the invention by that the compressed air reduction at normal stop compared to the Compressed air reduction in the event of an emergency stop is delayed.

The advantage of the invention is that you see the speed the compressed air reduction with relatively simple and yet very safe devices borrows can be regulated in such a way that a certain curve progression of the pressure diagramTr.es of the air as a function of time and thus a series of braking torque DiftgrasMen recovered, which guarantee a smooth braking in the Noraalftlle **

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According to one embodiment of the invention, the speed of the decomposition of compressed air is in the one to be vented The cylinder in an emergency stop and in a normal stop until the brake comes into effect is roughly the same size. At the The normal stop is then the further reduction in compressed air that takes place after this point in time compared to the reduction in compressed air delayed in the event of an emergency stop. The "has the advantage that the brake is very effective both during a normal stop and during an emergency stop intervenes quickly, but braking is more gentle with normal stop than with emergency stop.

This embodiment of the invention can do this be further developed that the exhaust air is introduced into an air chamber at normal stop, so that the in this Air chamber building up counter pressure delays the reduction of compressed air in the cylinder of the brake. As long as the wind kettle is still empty, so at the moment of triggering " of the braking process, the compressed air flows at a speed into the air chamber, which does not noticeably decrease compared to the discharge velocity into the atmosphere is. The counter-pressure that builds up in the air chamber grows slowly at first, and so does the outlet the air vessel is closed after an e-function,

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So the building up in the air vessel back pressure leads after a certain time to a tangible reduction in the outflow of the compressed air from the cylinder to the brake and eiusr Verlangsaoung the increase of the braking torque therefore ₀ After triggering the brake "process is the brake about the same speed engaged as with an emergency stop, but then the breath moment wakes up more slowly than with an emergency stop, the course of the reduction in compressed air over time now depends on the relationship between the volume of the air chamber and the volume of the brake cylinder - supply lines - air chamber system and also on this at what point in time an outlet opening of the air chamber is opened and what outflow cross-section this outlet opening has »For example, the size of the Vr'indkesoels can be selected so that while the Bresse is still dragging» In den Windle ····! a back pressure builds up, the moment the Mftieg but only verlangeaat can "play For others, the size of the air receiver ^ - be gawlnlt that grinds even while the brake is braked before the press, a pressure equalization tu system has adjusted, so the br -asaoe ^ ßfc Bleat «or grows. Are also by corresponding ^ <% Wstel de?

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above parameter tin · See execution tb «ü.« play possible, the «wipe an operating state li *» gan, at dta the braking moaent course according to dta Intingriffkofmta the brake remains the same at normal stop, an operating state, at dta d * s Breasaoaent only shortly after the standstill the press remains the same and an »operating state, at dta the brake aaaent grows steadily up to a standstill, but not as eohuell as btia Hothalt. It has been good that those execution fora of the invention, at dtntn the breasaoatst at the moment of the plague burn not wake up, least of all to housing oscillations tend.

As already mentioned, an outlet can be provided at the air chamber so that the air chamber is only opened after the press has stopped, so that the air chamber is emptied and is made ready for the next operation. In another Ausführungeform the invention, however, the air vessel tine aeration nozzle, which always 1st geb'ffnet whose Strönungsquerschnitt * doc3> iz ^ ewthlt 1st, DSQ this ^ ^ tro RungsQutrsonnitt YI * V g "gpä 'n u> ^« r to is Leitungsquerscbaitt is ventilated by the so slso the influence i <suf dust the diagram of the air pressure is negligibly small _B In this "Faü" Iaei4in aic>"TLSO

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in a suitably selected size of .vlndkeseele the Betrlebsverhältnisse achieve, in which the braking torque is no longer substantially increased even during the grinding of the brake, and gesapt ge \, the braking torque asymptotically tuntrebt his Endwjit "One can assume in general," a ⁵ uann the influence of the outflow nozzle on the air chamber is negligibly small if this cross section is about ten times smaller than the cross section of the line between the brake cylinder and the air chamber -Windkeasel at atmospheric pressure lasts about five times as long as in the skin, in which there is no Vindkescel connected to the Sntliiftunssleitim and the compressed air from the brake cylinder flows directly into the atmosphere which is the rise of the BreseiSQ xentes only slowed down, but not already during the grinding "as the brake asymptotically strives for an -n final value"

However, the invention can also still exist without Sindkeisel a different kind and vVelse be realized at one Embodiment of the invention, for example, in that

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with normal stop the outflow of the compressed air takes place through a smaller outflow cross-section than with emergency stop. This embodiment of the invention can be further developed in such a way that two valves are provided, only one of which is activated when the standard is stopped. The outflow cross-sections of the two valves can be the same or different. In the event of an emergency stop, either only the valve with the larger outlet cross section or both valves are activated. At normal stop, however, only the valve with the smaller outflow cross-section or, if both valves have the same outflow cross-section, only one of the two valves ₀

In other developments of this embodiment of the Invention can thereby achieve a smaller cross-section of the flood stream during normal stop be provided than in an emergency stop that the outflow cross section used in the emergency stop for the normal stop is reduced by an insert · The procedure can again be such that the insert time delayed after opening the valve in the Outflow cross-section is switched on. This time delay can be brought about by a time delay element be, or, in another embodiment of the

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According to the invention, the switching on of the insert in the outflow cross-section can be controlled by the engagement of the brake, for example in a mechanical manner. This last-mentioned embodiment of the invention has the advantage that it is independent of the wear on the brake and thus independent of the path that the brake plates cover before they come into engagement with one another.

Further features of the invention emerge from the following description of schematic diagrams, which are used for further purposes Serve to explain the invention.

Fig. 1 shows the compressed air layout P ,, the diagram dee braking torques
applied.

Bremenomentee If ,. and the speed η over time t

Pig. 2 shows scheme ti. Sch an embodiment of the invention using an air kettle.

Fig. 3 shows an embodiment of the invention when using two valves old different Ausetr ÖBquerschni ttexu

• Λ

Fig. 4 shows schematically an embodiment of the invention with only one valve, the flow cross section of which is variable.

Fig. 5 shows a detail of the embodiment

4 on a larger scale and in section near the line IY-IV ₀

In the embodiment of the invention shown in Fig. 2, 1 is shown with a pressurized air cylinder of the press brake, the sun brakes is vented. The compressed air in this cylinder is balanced by a spring arrangement. As soon as the air pressure in the brake cylinder 1 decreases, the spring arrangement presses the mutually movable parts of the brease la engagement with one another. The diagrams of the air pressure, the braking torque and the speed during this process are shown in FIG. As soon as an outflow opening of the brake cylinder is opened to trigger the Breee gate at time t _Q , the air pressure drops up to a point in time t *, for example after an e-function eo long. How dl

^Ί the

Force of the spring arrangement the / by the fresh air

builds counterforce overcomes and therefore the Solben la » Cylinders are predominant under the action of the ium

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can move, with the brake disks connected to it being moved against the opposing surfaces, driving the time in which the volume of the brake cylinder 1 is reduced, the? Air pressure in the brake cylinder 1 about the same, at least it decreases very much slower than in the time period between t and t. · At time t _2, the Bremslaaellen come to its counter surface for the piston in dta Βτβββzylinder 1 does not move more , the volume of the brake cylinder remains the same from this point on. If one assumes that the venting of the brake cylinder 1 takes place directly into the outside atmosphere, the air pressure in the cylinder 1 does not decrease rapidly again after a function from the time t "(compressed air curve 2 shown in dashed lines in FIG. 1), since the lamellae from the time tg from abut its mating surface, builds up in the MaBe ₉ in which the air pressure in the cylinder 1 is decreased, the braking surfaces of a brake torque IL. corresponding to the curve 3 drawn in dashed lines in Pig · 1 on · In the time between t ₂ and time t *, the surfaces that are decelerating one another still grind against one another. At time t »the face is braked, which is shown in Flg. 1 curve 4 of the Orehgahl curve η drawn in dashed lines is on Hull

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sunk. It can be seen that under these operating conditions, which correspond to the emergency stop, the press has already come to a standstill before the braking torque begins to roll ', Vert has reached. The time t is still in the or at the end of the steep branch of curve 3

These relationships just described occur, as already mentioned, at an emergency stop. In the event of an emergency stop, the in Fig. 2 shown embodiment of the invention Valve 5 with a large outflow cross section 6 is open. These" Ven + il is connected to a branch of a supply line 7, which connects a compressed air generator or the tapping point for compressed air28 with the brake cylinder 1 «

In the embodiment of the invention shown in FIG If a valve 8 is switched on in the line 7, this valve is activated during normal stop. At the outflow cross-section 9 of this valve fabric 8 is connected to an air chamber 10 in this embodiment of the invention, the an outlet 11 in the shape of a nozzle or again a * Has valve. If the valve 6 is energized at the normal stop and thereby the exhaust air of the brake cylinder «1 in d« n Windkessel 10 initiated, so I build in dtt Windkessel a counter pressure that reduces the compressed air in the

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Brake cylinder 1 delayed. It is desirable here that the decomposition of compressed air between the points t _Q and tg is not significantly delayed, but that a delay trst occurs after the point in time tp. This compressed air curve is shown in solid lines in FIG. 1 and is designated 12 at the beginning. In order to achieve this, the air chamber 10 must have a certain size, which depends on whether the outlet 12 is closed during the build-up of the counterpressure in the air chamber or what cross section this outlet cross section has. The curve of the branch 12 can be designed as desired. For example, is the outlet

until
closed, / the press is braked, so with a suitable selection of the size of the air chamber 10 the in Flg. 1 with 12 can be achieved · If the outlet cross-section is open from the start, however, a more or less steeply inclined curve 15 can be achieved. The curve of the braking torque 11 ′ then also runs correspondingly, the curve segment 14 of the braking torque diagram corresponding to the curve segment. At any point in time t ^ after the press has locked, the air chamber Ίθ is vented by opening the outlet 11 and made ready for a new braking process. The air pressure drops

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in the system on atmospheric pressure, the force with which the braking surfaces are pressed against each other correspond to the force of the spring arrangement, the increase in this force is shown by the curve section 15 of the brake torque a. At time te, the press sum comes to a standstill. Dl «of the curve 12 corresponding to the speed curve is denoted by 16. It can be seen that while the brake is _{still dragging between times t 2} and te, the braking torque initially rises sharply, but then asymptotically approaches a limit value, i.e. the braking torque remains approximately the same for a considerable period of time while the brake is grinding. You then get a very slow prease. The compressed air curve 15 corresponds, as mentioned above, to an operating state in which the outlet 11 of the air chamber 10 is already open from the start. The curve 13 roughly corresponds to the braking torque curve 17 and the speed curve 18.

In * the embodiment of the invention shown in FIG. 3 did the compressed air reduction not delayed by the fact that an air chamber is switched on, but there are la the supply line 7 is a valve 19 which is activated in the event of a hot stop with a large outlet cross-section 20 and one at normal stop controlled valve 21 with small outlet cross section 22

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switched on.

In the execution form according to Fig. 4 is in the supply line only one valve 23 switched on, which both in the event of an emergency stop ala is also activated at normal stop. Dieeee valve has a large outlet cross-section however, there is also a drive device (Hydraulic or electromagnet) 25 energized, the one use 26 in the outflow cross-section 24 against the effect a spring 27, which tends to keep the insert out of engagement, and therefore the cross-section 24 always to be kept open. In the illustrated embodiment of the invention, the insert 26 is only switched on when when the brake has come into engagement, i.e. at time to about the curve section 13 in rig. 1 corresponds and can be more or 'less inclined

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Claims (1)

Claims Press in which the press main shaft is vented a cylinder acted upon by compressed air is abbrensbsr and the braking in case of feces nit a Brememonent takes place which is greater than the braking torque applied in the normal case, characterized in that the compressed air reduction during normal stop compared to the compressed air reduction is delayed in the event of an emergency stop. 2) Prasse according to claim 1, characterized in that da.fi dl · speed of the compressed air reductiona in an emergency stop and in the normal stop until the brake comes into action (time t ₂ ) is approximately the same and in lfoms.lhs.lt only that which takes place after this time « elter · Compressed air reduction compared to the return air reduction in Rothalt is delayed. 5) press according to claim 1 or 2, characterized in that that at normal stop the exhaust air in an air chamber (10) is introduced so that the in this air chamber (10) * sleh back pressure that builds up delays the reduction in compressed air in the cylinder (1) of the brake. • ./. . £. 009815/0210 4) Press according to claim 3, characterized in that the size of the air chamber (10) is chosen so that, while the brake is still dragging, the air chamber a counter pressure builds up, which increases the braking torque at least slowed down. 5) press according to claim 4, characterized in that the The size of the air vessel (10) is chosen so that, at least during part of the time period, in which the press still grinds (between tp and te) «in Adjusts pressure equalization (curve 12) between the cylinder to be vented and the air chamber. 6) Press according to claim 4 or 51, characterized in that that the air chamber (10) can be vented after the press has stopped. 7) Press according to one of claims 4 to 6, characterized in that that der'Windkessel (10) has a ventilation nozzle (11), the flow cross-section of which is chosen so that the pressure reduction in the system cylinder (1) -supply line (7) -wind tank (10) at least to Atmosphirendseek « five times as long as without an air chamber (10) 009815/0210 8) Press according to one of claims 4 to 6, characterized in that that the cross section of the Auelaßdüse (11) min-. is at least ten times smaller than the line cross section (7) between the cylinder to be vented (1) and the air chamber (1ο). 9) ^ press according to claim 1 or 2, characterized in that that with normal stop the outflow of the compressed air takes place through a smaller outflow cross section (22) than with Emergency stop. 1C) Press · according to claim 9 »characterized in that two valves (19» 21) are provided, tob only one (21) when normal stop is activated. according to claim 10, characterized in that d * 0 «In Valve has a smaller flow cross-section (22) and is activated at normal stop «Hein · 12) Press according to claim 11, characterized in that it can be used the two valves have the same flow rate point. 009815/0210 13) Press according to claim 10 and one of claims 11 or 1 ?, characterized in that both valves are activated in the event of an emergency stop * 14) Press according to claim 9ι, characterized in that only one valve (23) is provided, the flow cross-section (24) of which is reduced by an insert (26) at the Noroalhalt. _φ 15) Press according to claim 14, characterized in that the insert (26) is delayed after opening of the valve (P?) can be switched into the outflow cross-section (24) is. 16) Press according to claim 15, characterized in that switching on the insert (26) in the flow cross-section (24) from the engagement of the brake (time t «) is controlled. 009815/0216