DE2921926A1 - Mine working area striding supports remote control - involves dual pressure valves conveying reversal impulse when two pressures are equal - Google Patents

Abstract

Operative functions, such as setting, exploiting or advancing, are set in motion by control impulses. The system is used in connection with hydraulic main control valves for individual units, in a remote control system for support units in underground mine working areas. Twin pressure valves are incorporated into impulse leads leading to the main control valves. These convey the impulse to reverse the main control valve only when the same pressure is in force at both control inputs of the twin pressure valve. The twin pressure valves have control connections which may be interchangeable. For striding support systems, this makes it feasible for a number of units to be controlled from a single position.

Description

Control for longwall units

The invention relates to a remote control for expansion units in underground longwall mining where control impulses are provided from one or more control stations to the hydraulic main control valves assigned to the individual expansion units be given that the work functions of the expansion, such as setting, robbing, backing, trigger.

There are known impulse controls for the advancing longwall mining, for example the so-called neighbor control.

The main control valve to which the pulse is applied is on the expansion arranged, whose work functions are thus controlled, while the Umachaltimpulse For reasons of safety, from command transmitter valves arranged on the adjacent extension can be fed to the main control valve via hose lines. As for every liberty function a control hose is required, there are usually 8 control hoses between the neighboring expansion units needed. When controlling both the left and This number doubles also for the right neighbor from an expansion. at a group control in which several expansion units are combined in a control group are to be controlled from a central control station, the Number of necessary control hoses from the number of expansion units times the Number of work functions.

Due to the large amount of material and the unclear Hose tangle has such a group control not enforce can, not to mention a control1, the several central control stations having.

However, such a control would simplify operation for mean the miner and, above all, better protection against dust nuisance to him offer because he donn control the expansion at a reasonable distance from the largest sources of dust on the strut, on the extraction machine and on the back Expansion, can make.

He could always choose his operator position so that he weather-wise seen - located in front of the expansion to be advanced, to 8o protection from the whirled up and to have dust carried along by the weather.

The object of the invention is to provide this described advantageous control option to accomplish. So it should be a hydraulic or a Pneumatic group controls are developed, which control several expansion units made possible from a central control station. In addition, this should also be Control of the individual expansion units from several separate units Control stands can be made from. The tubing and valve expenditure should be be kept low.

To solve this task, the control valves are in the Ispula lines to the main hydraulic control valves, which control the working functions of the adjustment units, such as setting, robbing back and the like, single $ eA two-pressure valves are used Only pass on the impulse to switch the main control valve if on pressure is applied to both control inputs of the two-pressure valve at the same time.

These two control lines are connected directly or indirectly to the command transmitter valves connected.

This can be done, for example, that a number of the command transmitter valves - E.g. the group number selector valve - to one control side of the to the certain expansion belonging two-pressure valves are connected, while another Group of control valves - e.g.

the work function selector switch - with the other control connection of the two-pressure valve is connected.

This results in control options that have a considerable Mean savings in control hoses. In addition, a possibility is created to control all expansion units of a control group from several control stands.

The invention is described in more detail below with reference to the drawings and reference is made to expansion options. It is just one embodiment shown that the control of 4 expansion units with 4 work functions each embraced by a steering position.

Pneumatic circuit symbols are used; of course you can also realize a hydraulic control.

The more solid lines represent those at the current valve position existing pressurized control lines.

The circuit diagram according to FIG. 1 is on the left in the dash-dotted frame 10 represents the central control station with the command valve, and that is above the group number switch 11 is shown, each of its 4 switch positions 1, II, III and IV refer to the associated expansion unit.

Its connections 1, 2, 3 and 4 give with the corresponding switch position a continuous impulse to the individual expansion units.

In the position shown, the control line 2 leads to pressure, so that the two-pressure valves a2, b2, c2 and d2 are acted upon at their ports xl. As a result, they are switched over, but do not yet pass on any impulse as long as you continue inichluß x2 is depressurized; they are now, as it were, in a stand-by position. A, B, C and D designate the control valves that perform the work functions the expansion, such as sitting, back and the opposite functions robbery or.

Follow up, should trigger. Their impulse lines are marked with a, b, c and d denotes, they are connected to ports x2 of the two-pressure valves, in such a way that the two-pressure valves each have an identical Arbeitsfwiktion Trains are assigned, are jointly connected to the corresponding 8 control line. So is in the position shown for example the command valve B pressed (arrow), which has a certain work function, for example the back, should initiate. All two-pressure valves are connected to the corresponding control line b connected to their connection x2, which this work function on the corresponding Should initiate main control valves of the various expansion units; it is this the valves: bl, b2, b3 and b4o The condition for the function of the two-pressure valve reads so that a switching pulse is only passed on when both the control connection xl and port x2 are pressurized. This condition will be in everyone only possible combination of a group number selector switch with a work function valve only apply to a two-pressure valve, in the case shown with the valve b2. The main control valve 311 is connected to the pressure-carrying output y of this valve, which triggers the selected function, for example the reverse process.

Although the valves a2, c2 and d2 also switched due to the impulse 2 no pulse is passed on because their ports x2 are depressurized. Even the pressurization of the valves bl, b3 and b4 brings at their ports x2 no effect as the connections xl are depressurized.

The main control blocks HI, H II, H III and H IV of the individual expansion units contain - in simplified form - the main control valves A 1, B I, C I etc. They can be used as directional control valves, also with pilot control valves or as unlocked check valves be trained. The pressure relief valves are not shown.

It can be seen that an expansion of the control group by further Expansion units is easily possible. Just a selector switch with several switching options is required and only one additional control hose per expansion. Instead of Selector switch, of course, individual valves can also be used.

The inventive concept expressed in FIG. 1 should be repeated in FIG are illustrated in a schematic representation: Every square corresponds to a two-pressure valve that is connected upstream of the main control valve. From the Group additional selector switch, position II, are all in the horizontal row II arranged two-pressure valves acted upon at their ports xl: a2, b2, c2 and d25 of the working function selector switch B, all two-pressure valves in the vertical Row applied to connections x2: b1, b2, b3 and b4. According to the characteristic Function of the two-pressure valve, this is the impulse to switch the main control valve only give when both connections are pressurized. This is given in Crossing point of both rows, at two-pressure valve b2. (Heavily framed). The two-pressure valve thus fulfills an AND function here.

For the transfer of the 16 switching functions drawn from the control station Only 8 control lines are required to the main control valves. These enormous tubing The savings are even more pronounced with larger control groups: with 10 expansion units, for example with 8 work functions each, 10 + 8 = 18 control hoses are required.

According to previous control technology, this would be 10 x 8 = 80 hoses necessary. This control according to the invention therefore saves a considerable amount of tubing and opens up new control options. The two-pressure valves required are simple in construction, reliable and very cheap; normal directional control valves can be used or in a particularly simple design, e.g. according to the symbol for valve d4 which are also connected to the pilot operated main control valves without tubing can be.

A more extensive capacity utilization of the control hoses can be still achieve by dividing the command control valves into more than two groups and linked with each other and / or each command pulse with each other is linked. In these cases, several two-pressure valves must also be used one behind the other be switched and possibly housed in the steering position, eo that already here a reduction in the number of hose lines required to fewer than the sum of the command valve is reached.

In addition, this control can be expanded by installing it of safety circuits, feedback and control elements, actual value display the work functions, scanning of the return path, as well as subsequent operations. Analogous The term "command valve" used here can also refer to impulse valves these expansion circuits are expanded, including e.g. B. also limit switches belong to sequence controls.

The further advantage of this control according to the invention is that that further control stations are connected at any point in the expansion group can be. The fact that the impulse lines a, b, c and d extend over the Extending the entire length of the expansion group accommodates this expansion. Even the impulse lines 1, 2, 3 and 4 can easily be lengthened. Further, the steering position 10 corresponding command transmitter valves can thus be controlled by means of double check valves Connect 12 - as indicated in control line 4. That way you can e.g.

in a control group comprising 10 expansion units each expansion can be controlled from any other expansion.

Claims (13)

Claims 1. Remote control for expansion units in the underground Longwall mining in which control impulses are sent from one or more control stands the hydraulic main control valves assigned to the individual expansion units be given that the work functions of the expansion, such as setting, robbing, backing etc. trigger, characterized by two-pressure valves (al, b1, etc.), which in the pulse lines (1, 2, 3, 4, a, b, c, d) are activated and the IPU1B for switching these main control valves Forward only if both control inputs of the two-pressure valve are at the same time Pressure is pending. 2. Remote control according to claim 1, characterized in that the both control inputs (x1, x2) of the two-pressure valves the command valve Cii, A, B etc.) of the steering position (10> are connected directly or indirectly. 3. Remote control according to claims 1 and 29, characterized in that that the command valve are divided into circuit groups. 4. Remote control according to one or more of the preceding claims, characterized in that a circuit group of the command transmitter valves to the Control lines ii is connected while another group of circuits is connected directly or is indirectly connected to the control connections x2 of the two-pressure valves. 5. Remote control according to one or more Ner preceding claims, that the control connections of the two-pressure valves are interchangeable. 6. Remote control according to one or more of the preceding claims, characterized in that the circuit according to group division the command transmitter valves is carried out according to task-related aspects. 7. Remote control according to one or more of the preceding claims, characterized in that a group of the command transmitter valves are those for the working functions the expansion units1 such. B. backing, sitting, robbing, responsible valves (A, B, C, D). so remote control according to one or more of the preceding claims, characterized in that a circuit group of the command control valves for preselecting the expansion group number of the relevant valves (11 / I, -II, -III, -IV) includes. 9. Remote control according to one or more of the preceding claims, characterized in that the 3 command transmitter valves are individually linked to one another are. 10. Remote control according to one or more of the preceding claims, characterized in that two-pressure valves are connected in series one behind the other are. ii. Remote control according to one or more of the preceding claims, d.g. that two-pressure valves are arranged in the control station. 12. Remote control according to one or more of the preceding claims, characterized by several control stations1 with the command valve via double non-return valves are connected to the control lines, 13. Remote control according to one or more of the preceding claims, characterized in that each of the control group connected add-on units is assigned a steering position from which Every puncture of every expansion can be controlled.