DE10319380B3 - Path-limiting device for an oscillating main piston in a hydraulic compression-tension testing machine has a fastening ring, spindles with stop nuts and a non-slip belt drive - Google Patents

Abstract

A fastening ring (3) fixes a path-limiting device on a platen (1) for a hydraulic testing machine. Three spindles (5) fasten rigidly on the ring and protrude from it. Each spindle has a top and bottom stop nut (6), which acts on its outer contour so that a belt drive like a toothed belt (9) can be attached on each nut without slippage. The spindles pass through slots in a piston flange (7).

Description

The The invention relates to a travel limiting device for a oscillating working piston in a hydraulic tension-compression testing machine.

Tensile pressure testing machines are available in many designs in the test technology: For example, such a test device in the DE 23 45 445 B2 described: In this hydraulic multi-chamber load cylinder for generating static and dynamic loads in test facilities, the stroke of the ring piston is fixed by the design. This has the disadvantage that the hub is not variably adjustable.

In the DE 100 04 335 A1 describes a testing machine for dynamic fatigue testing of alveolar polymer samples, where pressure can be applied to a sample through several horizontal plates that are vertically displaceable. In this case, the sample is applied to a fixed plate and the pressure on this sample is applied by a vertically movable plate whose oscillation is fixed by a drive.

Both testing machines is the disadvantage of the reason that the stroke of the piston or the Fix plates firmly and is not infinitely adjustable. This Disadvantage is eliminated by the invention described herein. Especially let yourself the path limiting device with only slight changes and mount adjustments on existing testing machines.

Also the DE 39 12 075 C2 describes a testing machine and a method for the mechanical testing of material samples and components in which spontaneous changes in the sample compliance should not lead to sudden compensating springbacks of the testing machine due to constant testing machine force.

In the DE 43 11 940 A1 a particular design of a universal testing machine is described in which the required high test load is applied by two hydraulic drive elements. A similar testing machine will be available in the JP 11083714 A1 described; However, here the test load is applied by four hydraulic test cylinder. On the execution of a path limiting device, as described in the present invention, is not discussed in the three last-mentioned writings.

in the Framework of material testing thus become different versions Servohydraulischer testing machines - as described - used. In these testing machines become common between the piston and the load frame clamped the corresponding specimens. Due to their functionality, these machines basically have the problem that the working piston due to incorrect operation or malfunction very quickly and can move uncontrollably. This can destroy Samples or the chuck and can thus with considerable financial losses and risk the operator connected. To avoid this, machines must be equipped with appropriate protection devices.

• a) Elektronische Grenzwertschalter
• b) Hydraulische Kraftbegrenzungen
• c) Mechanische Endanschläge

zu a) Die elektronischen Grenzwertschalter arbeiten nur bei einwandfrei funktionierender Maschinenelektronik. Deshalb ist die Absicherung bei Stromausfall nicht möglich. Außerdem ist diese Art der Schutzvorrichtung bei starken Netzschwankungen und äußeren elektromagnetischen Störsignalen störanfällig.
zu b) Die hydraulischen Kraftbegrenzungen müssen höher als die notwendigen Prüfkräfte eingestellt werden, um somit Regelungsprobleme der Prüfmaschinen zu vermeiden. Eine Begrenzung des Kolbenweges ist nicht möglich. Außerdem schützt diese Schutzvorrichtung nicht bei schnellen Kolbenbewegungen. Ein Beispiel für eine hydraulische Wegbegrenzungsvorrichtung eines Hobels ist in dem Patent DE 3017756 offenbart.
zu c) Mechanische Schutzvorrichtungen wirken oft nur in eine Richtung als Endanschlag und sind nicht verstellbar.Known protection devices are:

• a) Electronic limit switches
• b) Hydraulic force limits
• c) Mechanical limit stops

to a) The electronic limit switches work only with properly functioning machine electronics. Therefore, the fuse is not possible in case of power failure. In addition, this type of protection device is susceptible to interference in the event of strong mains fluctuations and external electromagnetic interference signals.
to b) The hydraulic force limits must be set higher than the required test loads, in order to avoid control problems of the testing machines. A limitation of the piston stroke is not possible. In addition, this protection device does not protect with rapid piston movements. An example of a hydraulic path limiting device of a planer is in the patent DE 3017756 disclosed.
to c) Mechanical guards often act only in one direction as an end stop and are not adjustable.

The The object of the invention is therefore a Wegbegrenzungsvorrichtung for one oscillating working piston in a hydraulic tension-compression testing machine in such a way that it is easy to handle and reliable is.

These The object is achieved by a Path limiting device solved with the features of claim 1.

• • universell für verschiedenen Zug-Druck-Prüfmaschinen nutzbar ist,
• • ein oberer und unterer Anschlag vorhanden ist,
• • unabhängig von Strom und Hydraulik ist,
• • stufenlos verstellbar ist,
• • im Arbeitsraum bedienbar ist,
• • leicht optisch kontrollierbar ist,
• • schnell, auch bei laufenden Versuchen, verstellbar ist,
• • immer im Eingriff ist und
• • störunanfällig ist.

The advantages of the invention are that the travel limiting device

• • universally usable for various tension-compression testing machines,
• • there is an upper and lower stop,
• • independent of electricity and hydraulics,
• • infinitely adjustable,
• • can be operated in the workspace,
• • easily visually controllable,
• • fast, even during ongoing experiments, is adjustable,
• • always engaged and
• • is susceptible to interference.

The Path limiting device for an oscillating working piston in a hydraulic tension-compression testing machine, consists of a fastening ring, by means of which the travel limiting device can be fastened on a machine table of the hydraulic testing machine. The mounting ring is universally applicable, as for adaptation to a train-pressure testing machine only the fixing ring on the machine table of the train-pressure testing machine to attach.

The Wegbegrenzung the path limiting device is by a respective upper and a lower stop nut on one on the mounting ring attached spindle are screwed, realized. Here are the Stop nuts on their outer contour so executed, that a wrap-around drive is attached to them without slip can. This has the advantage that the respective upper or the respective bottom stop nuts by the movement of the belt drive on the spindle together up or down to be rotated and thus the possible Way of the working piston easy and fast - even in running tests -, set can be. Furthermore this easy adjustment is easily visually controllable, because of the possible Path of the working piston only between the upper and lower stop nut possible is. An additional one Drive to set the path is not necessary and you are independent of Electricity or hydraulics. The setting is by using an upper and a lower stop nut on both sides effective and Wegbegrenzung is always engaged by these stop nuts. The usage ensures the spindle in connection with the stop nuts while a stepless adjustability of the stop nuts on the Spindle and thus a stepless adjustability of the possible Path of the working piston. At least 3 spindles must be present so that the wrapping drive is not in contact with the working piston occurs. The overall simple construction of this device ensures the Störunanfälligkeit this device.

According to one Embodiment of the invention, the piston flange is divided. This guaranteed The simple assembly with the working piston and ensures a positive connection with the working piston of the testing machine.

According to one Another embodiment of the invention, the fastening ring is divided executed. This has the advantage that the parts of the mounting ring on the machine table can be moved against each other and thereby the wrap drive can be stretched.

A Another advantageous embodiment of the invention is the division of the piston flange. This is necessary for this - regardless of Construction of the testing machine - mounted can be. After screwing the piston flange with the Working piston ensures a secure connection.

According to one Another embodiment of the belt drive both as Chain or timing belt executed be.

An embodiment of the invention is shown in FIG 1 to 3 shown.

• • einem Befestigungsring (3), mittels dem die Wegbegrenzungsvorrichtung auf einem Maschinentisch (1) der hydraulischen Prüfmaschine befestigbar ist,
• • mindestens 3 Spindeln (5), die auf dem Befestigungsring (3) starr befestigt sind und aus diesem herausragen,
• • je einer oberen und einer unteren Anschlagmutter (6) pro Spindel, wobei die Anschlagmuttern auf ihrer Außenkontur so ausgeführt sind, dass auf ihnen schlupffrei ein Umschlingungsantrieb, wie z.B. ein Zahnriemen (9), angebracht werden kann,
• • einem oberen schlupffreien Umschlingungsantrieb, der alle oberen Anschlagmuttern umschlingt und einem unteren schlupffreien Umschlingungsantrieb, der alle unteren Anschlagmuttern umschlingt,
• • einem geteilten Kolbenflansch (7), durch den die Spindeln (5) geführt werden, dessen Bewegung durch die untere und obere Anschlagmutter (6) begrenzt wird und der mittels Verschraubung eine mechanische starre Verbindung mit dem Arbeitskolben (2) bildet.

The 1 shows the overall structure of an embodiment of a travel limiting device for an oscillating working piston ( 2 ) in a hydraulic tension-compression testing machine according to claim 1. The path limiting device consists of

• • a fixing ring ( 3 ), by means of which the path limiting device on a machine table ( 1 ) of the hydraulic testing machine is fastened,
• • at least 3 spindles ( 5 ) on the mounting ring ( 3 ) are rigidly mounted and protrude from this,
• • one upper and one lower stop nut each ( 6 ) per spindle, wherein the stop nuts are designed on their outer contour so that they slip freely on a belt drive, such as a toothed belt ( 9 ), can be attached
• An upper slip-free belt drive which wraps around all the upper stop nuts and a lower slip-free belt drive which wraps around all the lower stop nuts;
• • a split piston flange ( 7 ) through which the spindles ( 5 ), whose movement through the lower and upper stop nut ( 6 ) is limited and by means of screwing a mechanical rigid connection with the working piston ( 2 ).

By the stop of the piston flange ( 7 ) against the stop nuts ( 6 ), the limitation of the path of the working piston is ensured according to claim 1 and 4. In 1 was the slip-free belt drive according to claim 5 designed as a toothed belt.

2 shows the two-part structure of the fastening ring ( 3 ) according to claim 3. The spindles ( 5 ) in the threaded holes for the spindles ( 11 ) screwed. In this embodiment, 6 threaded holes for 6 spindles are provided. Through the oblong holes ( 12 ), the screws are screwed in, which ensure the connection with the working table of the testing machine. Also, by moving the two parts of the mounting ring against each other, the clamping of the belt drive is possible.

The 2a gives the cutting plane AB of the fastening ring ( 2 ) again.

In 3 the transverse distribution of the piston flange ( 7 ) according to claim 2. The piston flange is divided and screwed together according to claim 4 and is connected to the working piston of the testing machine.

Installation of the travel limiting device

• 1. The split fastening ring ( 3 ) is placed on the machine table ( 1 ) and the piston flange ( 7 ) is connected to the working piston ( 2 ) of the testing machine easily screwed.
• 2. The spindles ( 5 ) are from above through slots of the piston flange ( 7 ) and the lower stop nuts and the lock nut ( 4 ) are screwed onto the spindles.
• 3. The spindles ( 5 ) are in the mounting ring ( 3 ) (round holes in 2 ) and with the locknuts ( 4 ) countered.
• 4. Then the split piston flange ( 7 ) firmly screwed to the working piston.
• 5. The locknuts ( 4 ) are fixed on the spindle ( 5 ) screwed.
• 6. The lower and upper stop nuts ( 6 ) are pressed against the piston flange ( 7 ) screwed backlash-free and the toothed belts ( 9 ) are launched.
• 7. The toothed belt ( 9 ) is - by moving the split mounting ring ( 3 ) in the oblong holes (see 2 ) And the fixing ring is attached to the machine table ( 1 ) firmly screwed.

Of the Structure of the device according to the invention takes place directly around the Piston rod. Thus, this is independent of the test setup and the workspace. The upper and lower stop nuts can be passed through the upper and lower wrapping drive (e.g., toothed belt) quickly and stepless - too while of the experiment - pretend (becoming after this assembly the upper or lower timing belt moves, so All upper or lower stop nuts move synchronously on the threaded spindles.) and the free path of the piston flange and thus the working piston is directly on the protection device readable / recognizable. The distance between the upper and lower Stop nuts determines the possible travel of the working piston and thus prevents inadmissible piston movements. The operation in the work space is simple and it is a good one optical control of the set stroke limitation possible.

It this is a mechanical path limitation that always is engaged and over the entire power range of the machine both in the pressure and in the Zugbereich is effective.

Farther the device is independent of Test set-up and thus universally applicable in other testing machines.

The Device thus provides effective protection for operators test set and examinees, because they are always engaged, immune to interference, effective on both sides and independent of electricity and hydraulics.

1

machine table

2

working piston

3

fixing ring

4

locknut the spindle

5

spindle

6

stop nut

7

piston flange

8th

Tested the hydraulic tension-pressure testing machine

9

toothed belt

10

Gas pressure vessels

11

threaded hole for spindle

12

Long hole for tensioning the belt drive

13

Positive connection of the piston flange

14

turnbuckles

Claims (5)

Path limiting device for an oscillating working piston ( 2 ) in a hydraulic tension-compression testing machine, consisting of • a fastening ring ( 3 ), by means of which the path limiting device on a machine table ( 1 ) of the hydraulic testing machine can be fastened, • at least 3 spindles ( 5 ) on the mounting ring ( 3 ) are rigidly mounted and protrude from this, • one upper and one lower stop nut ( 6 ) per spindle, wherein the stop nuts are designed on their outer contour so that they slip freely on a belt drive, such as a toothed belt ( 9 ), • an upper slip-free belt drive, which wraps around all the upper stop nuts and a lower slip-free belt drive, which wraps around all lower stop nuts, • a piston flange ( 7 ), through whose slots the spindles ( 5 ), whose movement through the lower and upper stop nut ( 6 ) is limited and with the working piston ( 2 ) is mechanically rigidly connected. Path limiting device according to claim 1, wherein the piston flange ( 7 ) and is screwed together and thus a positive connection with the working piston ( 2 ) of the testing machine. Path limiting device according to claim 1 or 2, wherein the fastening ring ( 3 ) is executed shared. Path-limiting device according to one of the claims 1 to 3, in which the piston flange ( 7 ) is divided and - regardless of the structure of the machine - with the working piston ( 2 ) can be screwed or adjusted in a desired position. Path-limiting device according to one of the claims 1 to 4, in which the upper and lower slip-free belt drive designed as a chain or toothed belt are.