DE2543646C2

DE2543646C2 - Device for driving a compression testing machine

Info

Publication number: DE2543646C2
Application number: DE19752543646
Authority: DE
Inventors: Bruno 5450 Neuwied; Elsen Reinhold W. Dr.-Ing. 5022 Junkersdorf· Sonnenberg Richard Dr.-Ing. 6209 Lindschied Flossfeder
Original assignee: Schlosser & Co Gmbh, 6209 Aarbergen
Filing date: 1975-09-30
Publication date: 1977-06-08

Description

raum 15 vorgesehen, der im Ausführungsbeispiel koaxial zum Hochdruckraum 7 angeordnet ist. Eine Führungsbüchse 14 kleidet diesen Druckraum 15 innen aus. Dieser Büchse entlang ist ein Stufenkolben 17 verschiebbar. Auf der seiner Belastungsfläche 18 gegenüberliegenden Fläche 19 is' ein abgestufter Druckstempel 20 vorgesehen, der mit seiner Druckfläche 21 in den Hochdruckraum 7 hineinragt, wozu er die Zwischenwand 14 in einer abgedichteten Führung 22 durchsetzt. In den Niederdruckraum 15 führt ein Druckkanal 23. Ein weiterer Strömungskana! 25 wird zwischen einer außen in die Führungsbüchse 16 eingearbeiteten Längsnut 26 und dem Zylindergehäuse gebildet Dieser Strömungskanal 25 verbindet den nicht beaufschlagten Rüum 27 des Niederdruckraumes 15 mit einem Druckflüssigkeitsvorrat. Im Druckstempel 20 ist noch ein Überströmkanal 30 ausgebildet, dessen eine öffnung 31 in den Hochdruckraum 7 und dessen andere öffnung 32 in den Niederdruckraum bzw. dessen nicht beaufschlagten Raum 27 einmündet, und zwar derart, daß diese Öffnung 32 nur in der Ausgangsstellung des Stufenkolbcns 17 (Zeichnung) offen ist, während sie beim Anhub dieses Stufcnkolbens von der Führung 22 verschlossen wird. Ein Überströmen der Hydraulikflüssigkeit zwischen den beiden Druckräumen ist also nur dann möglich, wenn der Stufenkanal 17 nicht beaufschlagt ist.Space 15 is provided, which is arranged coaxially to the high-pressure space 7 in the exemplary embodiment. A guide bush 14 lines this pressure space 15 on the inside. A stepped piston 17 is displaceable along this sleeve. A stepped plunger 20 is provided on the surface 19 opposite its loading surface 18, the pressure surface 21 of which projects into the high-pressure chamber 7, for which purpose it penetrates the partition 14 in a sealed guide 22. A pressure channel 23 leads into the low-pressure chamber 15. Another flow channel! 25 is formed between a longitudinal groove 26 machined externally in the guide bush 16 and the cylinder housing. This flow channel 25 connects the unpressurized area 27 of the low-pressure chamber 15 with a supply of pressurized fluid. An overflow channel 30 is also formed in the plunger 20, one opening 31 of which opens into the high-pressure chamber 7 and the other opening 32 of which opens into the low-pressure chamber or its unpressurized chamber 27, in such a way that this opening 32 is only in the starting position of the stepped piston 17 (Drawing) is open, while it is closed by the guide 22 when this Stufcnkolbens lifts. An overflow of the hydraulic fluid between the two pressure chambers is therefore only possible when the stepped channel 17 is not acted upon.

Die Antriebsvorrichtung arbeitet wie folgt:
1st ein Prüfkörper 12 auf die Druckplatte 10 aufgelegt, dann ist zunächst ein eventuell vorhandener Leerhub möglichst rasch zu überwinden, damit der Prüfkörper 12 an die Gegendruckplatte 3 anschlägt. Für diesen Anhub wird mittels einer Niederdruckpumpe (nicht gezeigt) durch den Strömungskanal 25 Flüssigkeit in den Raum 27 und durch den Überströmkanal 30 in den Hochdruckraum 7 eingepumpt und auf diese Weise der Druckkolbcn 8 rasch angehoben. Da der Raum 27 mit Hydraulikflüssigkeit gefüllt ist, bedarf es hierzu keiner großen Mengen. Befindet sich der Prüfkörper schließlich in Anschlag, so kann mit der eigentlichen Druckprüfung begonnen werden. Du/u wird nach Öffnung des Strömungskanulcs 25 auf Rückströinung der Hydraulikflüssigkeit der Stufenkolben 17 durch den Druckkanal 23 beaufschlagt. Mit seinem Anhub wird die Öffnung 32 des Überströmkanal·. 30 geschlossen, so daß aus dem Hochdruckraum 7 keine Flüssigkeit mehr ausströmen kann. Der Druckstempel 20 des Stufenkolbens 17 tritt nun mit der Druckkraft, die auf die Belastungsfläche 18 des Siufenkolbens 17 ausgeübt wird, in den Hochdruckraum 7 ein und unter der hierdurch erwirkten Drucksteigerung im Hochdruckraum wird der Druckkolbcn 8 belastet, der nunmehr mit erhöhtem Druck auf den Prüfkörper einwirkt. Ist die Druckprüfung beendet, dann wird der Druckkanal 23 auf Rückströmung umgestellt, und der Stufenkolben 17 kann durch Einspeisung von Druckflüssigkeit in den Raum 27 wieder in seine Ausgangsstellung zurückgeführt werden. Da zur Erreichung des hohen Prüfdruckes. auf den die Prüfmaschine eingestellt sein wird, wegen des Übersetzungsverhältnisses des Druckübersetzers der Beaufschlagungsdruck auf den Stufenkolben nur einen Bruchteil des tatsächlich auszuübenden Prüfdrukkes auszumachen braucht, genügt auch für die Betätigung des Stufenkolbens eine Niederdruckpumpe, die z'veckmäßigerweise die zur Beaufschlagung des Druckkolbens vorgesehene Pumpe sein wird.The drive device works as follows:
If a test body 12 is placed on the pressure plate 10, any idle stroke that may be present must first be overcome as quickly as possible so that the test body 12 strikes the counter pressure plate 3. For this lift, liquid is pumped through the flow channel 25 into the space 27 and through the overflow channel 30 into the high pressure chamber 7 by means of a low-pressure pump (not shown) and the pressure piston 8 is quickly raised in this way. Since the space 27 is filled with hydraulic fluid, no large quantities are required for this. When the test body is finally in the stop, the actual pressure test can be started. Du / u, after the flow channel 25 has opened, the hydraulic fluid flows back into the stepped piston 17 through the pressure channel 23. With its upward movement, the opening 32 of the overflow channel ·. 30 closed, so that no more liquid can flow out of the high pressure chamber 7. The pressure plunger 20 of the stepped piston 17 now enters the high pressure chamber 7 with the pressure force that is exerted on the loading surface 18 of the lower piston 17, and the pressure increase in the high pressure chamber causes the pressure piston 8 to be loaded, which now applies increased pressure to the test body acts. When the pressure test has ended, the pressure channel 23 is switched to return flow, and the stepped piston 17 can be returned to its initial position by feeding pressure fluid into the space 27. As to achieve the high test pressure. To which the testing machine is set, due to the transmission ratio of the pressure booster, the application pressure on the stepped piston only needs to make up a fraction of the test pressure actually to be exerted, a low-pressure pump is also sufficient for actuating the stepped piston, which is usually the pump provided for applying the pressure piston will.

Die Erfindung beschränkt sich nicht auf das dargestellte Ausführungsbeispiel. So ist es nicht unbedingt notwendig, den Stufenkolben koaxial zum Druckkolben anzuordnen. Die Beaufschlagung des Druckkolbens kann auch über eine eigene in den Hochdruckraum 7 einmündende Speiseleitung erfolgen. Zweckmäßig wird die Umschaltung der Flüssigkeitsströmungen und die Steuerung der aufeinanderfolgenden Kolbenbeaufschlagungen automatisch ausgeführt.The invention is not limited to the illustrated embodiment. It's not like that absolutely necessary to arrange the stepped piston coaxially to the pressure piston. The application of the The pressure piston can also take place via its own feed line opening into the high-pressure chamber 7. The switching of the liquid flows and the control of the successive ones is expedient Piston pressurization is carried out automatically.

Hierzu 1 Blatt Zeichnungen1 sheet of drawings

Claims

1 J 2, however, with separate translator and feed cylinder claims: the one whereby, in addition to the two pressure cylinders, additional control valves are required.

1. Device for driving a Druckprüfma- object of the invention is therefore for a machine, especially for concrete test specimens, with 5 compression testing machine to create a drive device on the test body acting pressure piston, fen, which in a simple manner the use of a which enables in a high pressure chamber of a pressure cylinder pressure booster.

housing can be acted upon with hydraulic fluid. To solve this problem, a drive device

characterized in that in the Druckzy- iung of the type mentioned according to the invention

cylinder housing (5) that in the high pressure chamber (7) as io characterized in that in the pressure cylinder housing

Plunger working pressure piston (8) a piston working in the high pressure chamber as a plunger

another low-pressure space (15) for a stepped piston pressure piston another low-pressure space for a

ben (17) is connected upstream, the stepped piston of which is connected upstream, its stepped

Pressure ram (20) through one of the high pressure chamber Pressure ram through one of the high pressure chamber from

(7) the intermediate wall separating the low pressure chamber (15) through into

wall (14) can be moved through into the high pressure chamber of the high pressure chamber of the pressure piston

The pressure piston (8) can be moved into it. is.

2. Device according to claim 1, characterized by the arrangement of a stepped piston, zweekmäzeich, that the stepped piston (17) with its Big coaxial to the pressure piston, in the cylinder housing of the Pressure ram (20) coaxial with the pressure piston (8) 20 pressure piston, is a significant simplification of the is arranged. Drive device achieved. Using the

3. Apparatus according to claim 1 or 2. thereby making the stepped piston as a pressure booster for the characterized in that in the stepped pressure ram the piston is acted upon by only one Nicderdruckpum- (20) an overflow channel (30) is formed, whose pe is necessary. The idle stroke of the Druckkolin the opening (32) opening into the low-pressure chamber can only be passed through quickly by 25 bcns and with the same then is open. if the stepped piston (17) is in the low-pressure pump, it can then be pulled out Starting position is. Apply the appropriate test force. The low pressure in the

4. Device according to one of claims 1 to 3, drive system allows weak dimensions characterized in that the low-pressure chamber of the hydraulic units.

(15) is not lined with a guide bushing (16), 30 A further simplification is achieved when im its outer longitudinal groove (26) with the cylinder housing stepped plunger of the stepped piston se (5) a flow channel (25) is formed in the not overflow channel, which the low pressure :. Space (27) of the low-pressure chamber connects to the high-pressure chamber only. (25) forms. when the stepped piston is in its starting position

35 is located.

The supply of hydraulic fluid to the

The low-pressure space is relieved if the Nicder

The invention relates to a device for driving a pressure chamber of a guide bush with a a compression testing machine, especially for concrete test outer longitudinal groove. the one flow channel for that body, forms with a pressure oil acting on the test body 40 is limited.

Pressure piston, which is in a high pressure chamber of a Further details and features of the invention

stationary pressure cylinder housing with hydraulic fluid are the following description of a Ausfühkcit can be acted upon. example. that in the drawing schematically

In the case of simple compression testing machines with non-adjustable is shown.

Barem stand and therefore fixed counter-pressure plate 45. The pressure testing machine shown for example results for test pieces of different heights and for concrete test pieces consists of a stand 1, a relatively high test space and thus a large, non-adjustable traverse 2, a stationary stroke height for the pressure piston. If the drive of the counter pressure plate 3 is attached. On a base plate 4 pressure piston by means of a high pressure pump, then the printing machine is a pressure cylinder housing 5, its delivery rate is low and the pressure piston 5 is placed. In an upper high-pressure chamber 7, the idle stroke area is only slowly overcoming, as a result of which a pressure piston 8 arises, with its pressure surface 9 protruding from the housing 5 and carrying a pressure plate 10, which is quite considerable in many tests. To eliminate this disadvantage, it has already been proposed between this pressure plate 10 and the counter pressure that the pressure piston be located in the idle stroke or plate 3, a test body 12. This low-pressure area extends through an additional conveyor system 55 to drive the test body in the embodiment star shown. Although this is a considerable example almost on the maximum distance between the acceleration of the pressure piston in the idle stroke area of the two pressure plates. Therefore, only a relatively high one is achieved, but this requires an additional device for a short idle stroke of the pressure piston until the prerequisite. The test specimen is clamped when testing concrete test specimens. However, if the test body is required to have high test pressures that are significantly lower than that shown, then the dichend, complex dimensioning of the pressure system, pressure piston 8, has to have a relatively long idle stroke. For such high pressures are also overcome in trade. As a plunger piston, the pressure piston 8 is not available as a series-produced armature. educated. It is equal to its entire height. This means that the manufacture of these testing machines has a cross-section and its impact surface 13 is complex and expensive. In order to be able to reduce the layout of hydraulic 65 the entire cross section of the high pressure chamber to lower pressures, 7 a. In the same printing cylinder housing 5, however, is, for. B. in presses, the use of pressure intensifiers below the high pressure rate 7 and through a The known pressure intensifiers work partition 14 separated from it, is a low pressure