DE3227966A1 - Mine prop with closed hydraulic system - Google Patents

Abstract

In a mine prop (1) with a closed hydraulic system, an inner tube (4) is guided in an outer tube (3) in a longitudinally displaceable manner, which inner tube (4) has at its inner end an end piston (6) sealed off from the outer tube (3). A piston (7) is displaceable in a floating and sealed-off manner in the inner tube (4). The surface (10) of the piston (7) facing the outer tube (3) defines a hydraulic space (11) of the inner tube (4), while the opposite surface (12) defines a compressed-air space (13) of the inner tube (4) and can be acted upon by compressed air for setting the mine prop (1). The hydraulic space (11) is connected to an annular space (21) between the inner tube (4) and the outer tube (3) via at least one aperture (20) provided in the inner tube (4) near the end piston (6). Outer tube (3) and inner tube (4) are sealed off from one another. The annular space (21) can be connected to a prop space (29) on the inner side of the end piston (6) via a connecting passage (28) of the outer tube (3), which connecting passage (28) has a directional control valve (27). A non-return valve (33) letting hydraulic fluid through from the hydraulic space (11) into the prop space (29) is provided in an aperture (32) of the end piston (6). <IMAGE>

Description

Investments joint-stock company

Pit ram with closed hydraulic system The invention relates to a pit punch according to the preamble of claim 1.

In known pit punches of this type, the setting is carried out with a hydraulic setting gun, which is used for setting with a setting valve of the pit ram can be coupled. A certain volume of hydraulic fluid is always fed into the closed hydraulic system fed in. This volume is used when stealing the Pit punch hosed to the outside and is lost. This mode of operation is uneconomical and cannot be used in dams or backfills, because the hydraulically setting building material does not come into contact with hydraulic fluid may come.

The invention is based on the task of setting the pit punch to be accomplished without the supply of hydraulic fluid.

This task is due to the in the characterizing part of claim 1 cited features solved. No feed is now required for the setting process from hydraulic fluid to the closed hydraulic system more.

Instead, compressed air is used as the setting medium, which is underground is available anyway. There is no hydraulic fluid when the new pit ram is stolen hosed more in the vicinity of the pit stamp. This leads to economical Mode of operation and avoids undesirable moistening of those carrying the pit punch Sole and dams.

With the features of claim 2 is a relatively simple one The compressed air can be brought in during the setting process. The connection can not with applied compressed air etzvorrichtung be closed so that at The compressed air setting device is not attached. Foreign bodies cannot enter the compressed air space the inner tube can penetrate.

Dne features of claim 3 bring relatively low structural Effort in creating the connecting channel.

According to claim 4 is a simple and quick operation of the pit punch guaranteed for setting and robbing.

With the features of claim 5, possible leakage losses supplement the hydraulic fluid in a simple manner and with little structural effort.

The invention is illustrated below with reference to the drawings Embodiment explained in more detail.

They show: FIG. 1 a longitudinal section through a pit punch in FIG a fully retracted position, Fig. 2 a compressed air setting device, partially in section, relative to a connection of the inner tube and FIG. 3 shows a partial Longitudinal section through the pit punch according to FIG. 1 in its fully extended position.

Fig. 1 shows a pit ram 1 with a closed hydraulic System.

In an outer tube 3 welded to a base 2 there is an inner tube 4 longitudinally displaceable, the on his facing the outer tube End of an end piston sealed against an inner surface 5 of the outer tube 3 6 has.

In the inner tube 4, a piston 7 is floating and through a sealing ring 8 with respect to an inner surface 9 of the inner tube 4 in a sealed manner. One The surface 10 of the piston 7 facing the outer tube 3 delimits a hydraulic space 11 of the inner tube 4, while an opposite surface 12 of the piston 7 a Compressed air space 13 of the inner tube 4 is limited. The surface 12 of the piston 7 is for Setting the pit punch 1 can be acted upon with compressed air. This is done through a Opening 14 in the outer end of the inner tube 4, on the one hand with the compressed air space 13 and on the other hand with a connection 15 for one designed as a setting gun (Fig. 2) Compressed air setting device 16 is connected.

On the right in Fig. 2, the compressed air setting device 16 is at a distance of the connection 15 of the inner tube 4 is drawn.

The compressed air setting device 16 has a conically tapering Mouthpiece 17, according to the left figure in Fig. 2 in the coupled state a sealing cuff 18 of the connection 15 cooperates in a sealing manner.

The coupling between the compressed air setting device 16 and the connection 15 takes place via a bayonet fitting. 3 19.

The hydraulic space 11 of the inner pipe 4 is in the vicinity over several of the end piston 6 provided in the inner tube 4 openings 20 with an annular space 21 is connected between the inner pipe 4 and the outer pipe 3. The outer tube 3 is on its end surrounding the inner tube 4 is coupled with a grip ring 22 and through a sealing ring 23 is sealed with respect to the grip ring 22. The grip ring 22 in turn has a sealing ring 24 and a scraper ring 25, which with an outer surface 26 of the Inner tube 4 cooperate.

The annular space 21 is via a 3-way / 3-position valve 27 having Connection channel 28 of the outer tube 3 with a stamp space 29 on the hydraulic space 11 facing away from the side of the end piston 6 can be connected. The connecting channel 28 is partial defined by a connecting pipe 30 laid outside the outer pipe 3.

Further parts of the connecting channel 28 are in the grip ring 22 and the bottom 2 formed. The directional control valve is used to relieve the graphic representation 27 in Figure 1 with the valve symbol and its connecting lines next to the actual Pit mark 1 added.

The directional control valve 27 has three switching positions and is manually operated and is drawn into the one shown in FIG. 1 by reversing springs arranged on both sides Preloaded center position. The connecting channel 28 is in this middle position interrupted, which is necessary for setting the pit punch 1. To steal the Pit punch 1, the directional control valve 27 in Fig. 1 is switched through downwards, so that the connecting channel 28 is open. The third switch position is used to with a hydraulic filling line 31 hydraulic fluid to supplement leakage losses feed into the connecting channel 28 and thus into the closed hydraulic system.

In an opening 32 of the end piston 6 is a spring-loaded Check valve 33 is provided, which in Fig. 1 for clarity in turn with his Valve symbol is added. The check valve 33 allows hydraulic fluid through only from the hydraulic chamber 11 into the stamp chamber 29.

In an opening 34 of the base 2 is a pressure relief valve 35 is used and again drawn with the valve symbol in FIG. 1 for clarity.

The injection pressure of the pit punch 1 and thus the nominal load is adjustable via the pressure relief valve 35. If the rock pressure is exceeded the nominal load causes, the pressure relief valve 35 opens and injects hydraulic fluid away. Destruction of the pit punch 1 is thus prevented. Rather, the Pit punch 1 is increasingly pushed in and can eventually be stolen.

The pit punch 1 works as follows: For setting the pit punch 1 from the fully retracted position shown in FIG. 1 is the compressed air setting device 16 is coupled to the connection 15 and compressed air is fed into the compressed air space 13. As a result, the piston 7 is driven downwards and displaces hydraulic fluid from the hydraulic chamber 11 through the check valve 33 into the punch chamber 29. As mentioned, the directional control valve 27 is in the position shown in FIG Middle position, so that the connecting channel 28 is interrupted. So it builds up in the stamp chamber 29 hydraulic pressure, which is effective due to the larger lower surface of the end piston 6, the end piston 6 and thus the inner tube 4 upwards extends.

In the process, hydraulic fluid is released from the annular space 21 through the openings 20 through into the hydraulic chamber 11 and out of this through the check valve 33 expressed. The end piston 6 is opposite the inner surface with a sealing ring 36 5 of the outer tube 3 sealed.

If there is insufficient resistance, this extension continues of the pit punch 1 to the fully extended position shown in FIG. 3 away. In the position according to FIG. 3, a stop ring 37 has been used to limit the travel of the end piston 6 is placed on an inwardly projecting annular shoulder 38 of the grip ring 2.

As soon as the pit punch 1 is set, the compressed air setting device 16 removed.

To steal the pit punch 1, the directional control valve 27 is in its according to Fig. 1 lower switching position switched through and thus the connecting channel 28 opened . The hydraulic fluid is by the weight of the inner tube 4 and the related components from the stamp space 29 through the connecting channel 28, the annular space 21 and the openings 20 are pressed back into the hydraulic space 11. As a result, the inner pipe 4 moves into the outer pipe 3. The in the compressed air space 13 Any air present leaves the inner tube 4 through the connection 15.

Claims (5)

Anlagen Aktiengesellschaft PATENT CLAIMS 1. Pit stamp (1) with a closed hydraulic system that connects to the outside of the pit ram (1) is connected by a filling valve and a pressure relief valve (35), and with an inner tube (4) which is guided in a longitudinally displaceable manner in an outer tube (3) and which at its end facing the outer tube (3) an opposite an inner surface (5) of the outer tube (3) has sealed end piston (6), characterized in that that in the inner tube (4) a piston (7) can be moved in a cantilevered and sealed manner, whose surface (10) facing the outer tube (3) forms a hydraulic space (11) of the inner tube (4), and its opposite surface (12) has a compressed air space (13) of the inner tube (4) and for setting the pit punch (1) with compressed air can be acted upon so that the hydraulic chamber (11) has at least one in the vicinity of the end piston (6) in the inner tube (4) provided opening (20) with a Annular space (21) between the inner tube (4) and the outer tube (3) is connected that the outer tube (3) at its end surrounding the inner tube (4) opposite the inner tube (4) is sealed (23,24) that the annular space (21) via a directional control valve (27) having connecting channel (28) of the outer tube (3) with a stamp space (29) connectable on the side of the end piston (6) facing away from the hydraulic chamber (11) is, and that in an opening (32) in the end piston (6) Hydraulic fluid from the hydraulic space (11) into the stamp space (29) Check valve (33) is provided. 2. Pit punch according to claim 1, characterized in that the Inner tube (4) at its outer end one side with the compressed air space (13) and on the other hand with a connection (15) for a compressed air setting device (16) having connected opening (14). 3. Pit punch according to claim 1 or 2, characterized in that the connecting channel (28) partially through a pipe laid outside the outer tube (3) Connection pipe (30) is defined. 4. Pit punch according to one of claims 1 to 3, characterized in that that with the directional valve (27) the connecting channel (28) for setting the pit punch (1) can be locked and opened for robbery. 5. Pit punch according to one of claims 1 to 4, characterized in that that a directional control valve (27) forming the filling valve in a switching position Hydraulic filling line (31) is connected.