DE1143469B - Valve for controlling hydraulic support frames for mining operations - Google Patents

Description

Valve for controlling hydraulic support frames for mining Extraction operations The invention relates to a valve for controlling hydraulic systems Extension frames for mining operations with a hand-operated Relief valve and a pre-relief valve is equipped.

For devices used in mining that have a self-contained have hydraulic system, such as. B. hydraulic pit ram, are indeed Valves become known, which also have a hand-operated relief valve and have a relief valve.

In contrast to this, hydraulic support frames are converted into hydraulic ones Line system switched, which is kept continuously under a certain pressure will. This means that all hydraulic support frames are continuously supplied with a pressure medium is supplied, which is under a largely constant pressure.

This difference means that the operation of a valve to Control of hydraulic support frames for mining operations only in this respect can be compared with the mode of operation of a hydraulic pit ram can, than when relieving both the hydraulic support frames and the hydraulic pit ram due to a pre-unloading that requires less force the devices a lighter main relief must be effected. To the solution Numerous design variations of this problem are known in the art.

Timely, however, poses a significant additional problem and secure closure of the pressure medium inflow line to the pressure chamber of the extension frame This problem does not arise with hydraulic pit rams. In general special shut-off valves are switched on in the pump inflow line, which are used for Completion of the pump inflow line before relieving the expansion frames.

In contrast, the invention makes it possible through a meaningful combination the relief and pre-relief valves with which the pump supply line is shut off Valve an approximately simultaneous and automatic shut-off of the pump inflow line to achieve which inevitably only when the pre-relief or relief valve is actuated takes effect.

The invention achieves this goal in that the manually operated, the valve spindle lifting the relief valve body is hollow and one against it the spring force contains outwardly displaceable bolts by the before impact the spindle on the relief valve body for pressure equalization and reduction the actuation force requirement in a known manner the pre-relief valve is opened, whereby a valve ball or the like can be controlled by the pre-relief valve is that when the pre-relief valve opens, the pump inflow line to the pressure chamber of the extension frame, while the middle of the relief valve spindle, the relief valve and the pump inflow shut-off body on a common Axis lie.

By combining not only the relief valve with the pre-relief valve, but also these two valves with the shut-off valve for the pump inflow line, an extremely space-saving arrangement is achieved in the sense that at Immediately and automatically, the pump supply line is shut off to relieve the pressure on the support structure will.

In the drawing is an embodiment of an inventive Valve for controlling hydraulic support frames for mining operations shown in vertical section.

In a valve housing 1 is a pump inflow line 2 for the connection provided on a line network leading to a pressure pump. From the pump supply line from the pressurized oil passes a valve ball 3 serving as a check valve through a channel 4 into the actual cylinder space. A safety valve s is adjustable to the desired safety pressure.

One that can be operated by means of a handwheel 9 and has a thread 10 Valve spindle 8 engaging in a corresponding thread of valve housing 1 is hollow and contains a spring 13 displaceable towards the outside Bolt 12. This bolt 12 opens a pre-relief valve 11 before the Valve spindle 8 on a relief valve body 6 for the purpose of pressure compensation and reduction of the actuation force requirement. It is through the Vorentlastungsventilll a valve ball 13 or the like. Controllable when the pre-relief valve is opened the pump inflow line 2 closes off to the pressure chamber of the support frame.

On the lower end of the valve spindle 8 is an optionally adjustable Pressure ring 14 screwed on, the lower end face of which on the relief valve body 6 strikes this from its valve seat 7 against the action of the closing spring 15 to pull off his seat.

Since the middle of the relief valve spindle8, the pre-relief valve 11 and the valve ball 3 are on a common axis, the inevitable Actuation of the valve ball 3 in the sense of the completion of the pump inflow line 2 automatically guaranteed.

Claims (1)

PATENT CLAIM: Valve for controlling hydraulic support frames for mining operations, with a manually operated relief valve and a pre-relief valve, characterized in that the manually operated, the Relief valve body (6) lifting valve spindle (8) is hollow and one opposite Contains spring force outwardly displaceable bolt (12) by the before impact the spindle (8) on the relief valve body (6) for the purpose of pressure equalization and reduction the actuation force requirement in a known manner the pre-relief valve is opened, whereby a valve ball (3) or the like through the pre-relief valve. is controllable, the pump inflow line when opening the pre-relief valve (2) to the pressure chamber of the extension frame, while the center of the relief valve spindle (8) of the pre-relief valve (11) and the valve ball (3) on a common Axis lie. Considered publications: German Patent Specifications No. 872191, 872192, 887 784, 967 341; German interpretation document No. 1009138.