Method of controlling a pump apparatus for conveying viscous material, and control system for such a pump apparatus

Abstract

In a method of controlling a pump apparatus for conveying viscous material from at least two main delivery cylinders to a delivery pipeline, a sequence control is provided which runs a sequence program for executing operation of at least two control elements of the pump apparatus in a fixed timing sequence.

1 . A method of controlling a pump apparatus for conveying viscous material from at least two main delivery cylinders to a delivery pipeline, comprising the step of providing a sequence control having a sequence program for executing operation of at least two control elements of the pump apparatus in a fixed timing sequence.  
   
   
       2 . The method of  claim 1 , wherein the sequence program is executed at a running speed which is suited to an actual conveying speed of viscous material in the delivery pipeline.  
   
   
       3 . The method of  claim 2 , wherein the actual conveying speed is determined by a flow gauge in the delivery pipeline of a main hydraulic cylinder.  
   
   
       4 . The method of  claim 1 , wherein the sequence program is executed iteratively.  
   
   
       5 . The method of  claim 1 , wherein the sequence control includes a first sequence program and a second sequence program executed in succession and respectively triggered to commence by a start signal produced by a position sensor which directly or indirectly ascertains a piston position of a main delivery cylinder.  
   
   
       6 . The method of  claim 1 , wherein at least one of the control elements is operated of the control elements provided for operating a drive member selected from the group consisting of drive of the main delivery cylinders, drive of a switchable gate mechanism of the pump apparatus, shut-off valve of the pump apparatus, and drive of a compensating cylinder of the pump apparatus.  
   
   
       7 . The method of  claim 6 , wherein the sequence program executes at least one of the processes selected from the group consisting of start of a pump stroke of the compensating cylinder and simultaneous closing of the shut-off valve, change-over of a pump operation of both main delivery cylinders, reduction of a safety pressure of a main hydraulic pump for pre-compressing, switch-over of the gate mechanism, highly compressing to attain an actual conveying pressure and opening of a shut-off gate.  
   
   
       8 . The method of  claim 1 , using a stored-program controller.  
   
   
       9 . The method of  claim 1 , wherein a rotation of a camshaft with cams for switching the control elements is triggered by a start signal.  
   
   
       10 . The method of  claim 9 , wherein the rotation of the camshaft is halted, when the camshaft has rotated about a rotation angle defined by the sequence program to effect the operation of the control elements.  
   
   
       11 . The method of  claim 10 , wherein the rotation angle is 180°.  
   
   
       12 . The method of  claim 10 , further comprising the step of triggering a signal for halting rotation of the camshaft.  
   
   
       13 . The method of  claim 10 , further comprising the step of disengaging a clutch for halting rotation of the camshaft, with the clutch connecting the camshaft with a reduction gear unit of a drive.  
   
   
       14 . The method of  claim 9 , further comprising the step of triggering the start signal, when a main delivery cylinder approaches an end position.  
   
   
       15 . The method of  claim 9 , further comprising the steps of driving the camshaft by means of a drive motor, ascertaining a volumetric flow-rate of a hydraulic pump of the pump apparatus by means of a measuring sensor, and matching a speed of the drive motor to the volumetric flow-rate.  
   
   
       16 . The method of  claim 1 , further comprising the steps of switching a gate mechanism of the pump apparatus, and maintaining a delivery of viscous material also during switch-over of the gate mechanism.  
   
   
       17 . The method of  claim 1 , further comprising the steps of operating an intaking one of the main delivery cylinders at a piston speed which is greater than a piston speed of a pumping one of the main delivery cylinders so that an intake port is closed after conclusion of the intake stroke, whereupon a compression stroke is executed and a connection to the delivery pipeline is cleared before the pumping main delivery cylinder reaches its end position, and starting execution of the sequence program by a start signal from a position signal shortly before the intake stroke ends to thereby trigger at least one process selected from the group consisting of closing the intake port, pre-compressing drawn viscous material, highly compressing to attain an actual delivery pressure, opening a connection to the delivery pipeline, switching a main hydraulic pump to a new pump stroke, closing a connection of the other one of the main delivery cylinders to the delivery pipeline, and starting its intake stroke and opening its intake port.  
   
   
       18 . A control system for a pump apparatus for conveying viscous material, comprising a camshaft having at least one cam for actuating a contact member for operating a control element of a pump apparatus having at least two main delivery cylinders for conveying viscous material.  
   
   
       19 . The control system of  claim 18 , wherein one cam is assigned to a control piece for switching at least one control element selected from the group consisting of drive of the main delivery cylinders, drive of a switchable gate mechanism of the pump apparatus, shut-off valve of the pump apparatus, and drive of a compensating cylinder of the pump apparatus.  
   
   
       20 . The control system of  claim 18 , further comprising a position sensor for direct or indirect determination of at least a piston position of a main delivery cylinder.  
   
   
       21 . The control system of  claim 18 , further comprising a clutch for connecting the camshaft to a drive.  
   
   
       22 . The control system of  claim 21 , wherein the drive has a reduction gear unit.  
   
   
       23 . The control system of  claim 21 , further comprising a fluid-operated motor for driving the camshaft, said hydraulic motor being disposed in a fluid flow of a primary hydraulic pump for driving the main delivery cylinders or in its return flow.