Electrohydraulic control system

#The present invention relates to an electrohydraulic control system for an underground support system with a valve block which accepts grouped electrically-operated actuators for example electro-magnets and several control valves for hydraulic valves switched with the said actuators which electrohydraulic control system further comprises a circuit board containing an electronic circuit, to which all the actuators of the valve block are connectable through a disconnectable plug connector, by which disconnectable plug connector the circuit board is connectable to a controller for data communication, data recording and evaluation of operational status data from support units connected thereto.

#Previously proposed electrohydraulic control systems of this construction have long been in use for underground workings. It is also previously proposed to integrate the actuators, which generally comprise electro-magnets, and the hydraulic valves of a mutually adjacent support unit on a valve block, which is fixed to the powered support assembly of a support unit. For safety reasons the controller for the electrohydraulic valves on said valve block, which is provided with manually operated combined electric locks and circuit controllers and an automatic safety device, is fixed in each case to the adjacent powered support assembly and connected to the electro-magnets either directly through a cable connector or with interposition of a valve actuation strip. In embodiments with a valve actuation strip, the strip has a circuit board housed in a protective enclosure, and the circuit board is provided with socket outlets which are connected with the actuators via individual plug connectors. A disadvantage of this is that electrical connection of both the actuators and the electro-magnets to the valve actuation strip is time-consuming, and due to the large number of connectors with associated cables running along the powered support assembly, there are numerous sources of error for potential mechanical, electrical or electronic misconnections. The time required to connect all the actuators to the valve actuation strip is considerable and care must be taken to ensure that, it is possible to detect using the control system which actuator, and therefore which hydraulic valve is connected to which connection on the valve actuation strip. The personnel making the connections must also check carefully that all the connections are made and assigned correctly.

#The current assignee has previously proposed and trialled various modifications for said electrohydraulic control systems with valve actuation strips. It is also previously proposed from DE 37 08 902 to connect the controller not by means of individual cables, but by means of a standard terminal block with plain couplers to the valve actuation strip, from which individual cables then run to the electro-magnets. All the plug connections and all the electrical bonds can be made simultaneously through the terminal block and the back of the controller.

#An example of an electrohydraulic control system made in accordance with the present invention will now be described with reference to the accompanying drawings, in which:

#FIG. 1 shows a schematic representation of the system structure of an electrohydraulic control system according to the invention;

#FIG. 2 shows a cross-sectional view of a hood according to the invention with integrated circuit board and connector parts;

#FIG. 1 shows a schematic representation of an electrohydraulic support control system 10 comprising a standard valve block 1 in which various rows of location holes (not shown) above and adjacent to each other are formed to take the valve cartridges (not shown) of hydraulic control valves that are switchable as actuators by means of electrically-operated electro-magnets 2, 2′. A separate electro-magnet 2, 2′ is provided for each control valve and the electro-magnets 2, 2′, together with the control valves in valve block 1, are arranged on the back 3 of the valve block 1 and grouped in a preselected pattern of dispersion. The pattern of dispersion may comprise for example of two rows of five electro-magnets 2, 2′. A plug-in socket 5 into which a connector part 6 or 6′ can be inserted for electrical connection of the electro-magnets 2, 2′ is connected at the top 4 of each electromagnet 2, 2′. The connector parts 6, 6′ are fixed on a circuit board 7 which is permanently fixed to the back 8 of a hood 9 and is protected from ingress of dust and moisture by means of sealing compound 19. The circuit board 7 is provided with electronic components and PCB tracks (not shown in detail) in order to switch one or more of the electro-magnets 2, 2′ independently of signals transmitted to the circuit board 7 from a primary controller 20 via the cable connection 21.

#The valve block 1 is fixed to a powered support assembly (not shown) of a support system comprising a large number of support units, the controller 20 being itself fixed to the adjacent powered support assembly to control said valve block 1, which in addition to control switches also has an emergency switch and combined electric locks and circuit controllers on the front, so that in emergency situations, e.g. misconnections, the control valves in valve block 1 may be switched manually from a protected position. The controller 20 is linked via cables 22 and 23 to other controllers (not shown) located on the adjacent powered support assemblies or support units.

#The invention allows simultaneous connection of all the electro-magnets 2, 2′ with the circuit board 7. The circuit board 7 is located in the back 8 of the hood 9 which is attachable to the back 3 of the valve block 1 which circuit board 7, when the hood 9 is assembled, forms a sheet over all the electro-magnets 2, 2′. This is now explained further with reference to FIGS. 2 to 4.