FR2842849A1 - Concrete or mortar feed pump control system has two kinematically linked controls for flow rate and third for compressed air circuit - Google Patents

Abstract

The control system for a concrete or mortar feed pump with an extension pipe and lance that is connected to a compressed air circuit has two controls, the first (12, 18) of which can be set in a stable position for stopping the pump, a second position for maximum output speed, and intermediate positions for a varying output level. The second control (32) consists of a two-way power cylinder linked kinematically to the first for moving it into the second position, while an adjustable locking element (36) can fix the first control in an intermediate position. The compressed air circuit is equipped with a third control (46), preferably in the form of a distributor, which also operates the second control and at a given air pressure causes it to move the first control into its maximum output position.

Description

The present invention relates to a pump control system for

  variable flow for spraying or pumping concrete or mortar. Spraying machines have a receiving hopper into which the concrete or mortar is poured after it has been produced. The outlet opening of the receiving hopper is generally extended by a Moineau pump which is itself capable of being extended by piping terminated by a lance into which compressed air via a circuit is capable of being injected to spray concrete or mortar

  against a vertical wall or on the floor.

  The Moineau pump can be driven in rotation by control means comprising a hydraulic pump with variable displacement making it possible to drive a hydraulic motor. The latter is connected to the rotor of the Moineau pump to vary its rotation speed and

therefore its flow.

  The hydraulic pump is generally provided with a control lever which is capable of being driven from a first equilibrium position corresponding to the stopping of the pump to a second position corresponding to a maximum speed of transport of the concrete in said piping. The intermediate positions located between the first and second positions corresponding to intermediate speeds of

transport of concrete.

  In addition, the hydraulic pump is double-flow to allow driving the Moineau pump in the opposite direction so as to suck the concrete from said piping and decompress it. To this end, the control lever is capable of being driven into a third position, opposite to said second position from said first equilibrium position, said third position corresponding to the reverse drive of the

sparrow pump.

  Thus, the Moineau pump is controlled by the fluid flow control, which is achieved by the hydraulic pump. The lever generally controls the inclination of a plate against which the pumping pistons are supported and it is capable of being driven by describing at least one portion of the disc, in a first direction of rotation gradually so as to increase the flow rate. and thus the speed of the sparrow pump. It is likely to be driven in the opposite direction by passing through said position of equilibrium or neutral and to allow

  pump drive in reverse.

  The end of said lever of certain hydraulic pumps is embedded in the groove of a piston disposed substantially perpendicular to the lever and substantially parallel to the plane of said portion of disc that it describes. Said piston is capable of being driven, elastically, in translation around said equilibrium position corresponding to the neutral point of the pump. In this way, when the piston is in equilibrium, the pump is stopped. The pump flow is adjusted in

  blocking said piston in translation in a determined position.

  A problem which arises and which the present invention aims to solve is then to provide a control system, which not only makes it possible to maintain the hydraulic pump at a constant but adjustable flow rate by locking said control lever in a determined position, but also which allows an operator to control said system from the lance located at the end of the piping, the control system being produced at an advantageous cost to

  starting from the elements of existing devices.

  To this end, the present invention provides a control system comprising: second control means kinematically connected to said first control means and capable of actuating them towards said second position; adjustable blocking means capable of causing the blocking of said first control means between said second position and said first equilibrium position so as to maintain said first control means in a fixed position corresponding to a determined speed of transport of the concrete; and third control means connected to the compressed air circuit capable of controlling said second control means so that: when the compressed air delivers at a pressure Pl in the lance, said second control means actuate said first control means towards said second position; and when the injection of compressed air is cut off, the compressed air reaching a pressure P2> P1 in the circuit, said second control means actuate said first control means in

said position of equilibrium.

  Thus, a characteristic of the invention resides in the mode of driving said first control means using said second control means, which actuate these first control means and maintain them in a fixed and determined position thanks to said means of adjustable blocking. In this way, said adjustable blocking means are capable of being pre-adjusted before the pump is put into operation and then the second control means maintain in fixed position, as long as they are activated, said first control means between said first position corresponding to the maximum concrete flow and said equilibrium position. The third control means have two activation states. A first state corresponding to the air pressure P1 delivered in the lance and making it possible to control the second control means so that they actuate said first control means towards said second position. And a second state corresponding to the pressure P2> P1 of the circuit when it is closed at the level of the lance by the operator and which causes the return of the first control means to the equilibrium position. Obviously, the pump is capable of being controlled in rotation after a stop, by reopening the compressed air circuit at the end of the piping, the pressure of the circuit falling to the

pressure Pl.

  According to a particularly advantageous embodiment of the invention, said second control means comprise a jack supplied by a distributor, the rod of which is capable of controlling said first control means to actuate them towards said second position as long as the fluid a first chamber of said cylinder is under pressure. Thus, thanks to the jack operating in an all or nothing mode, and by means of adjustable blocking, the first control means are capable of being actuated and of being maintained in a fixed fixed position as long as the first chamber of the jack is

under pressure.

  Advantageously, said adjustable blocking means consist of a stop movable in translation, capable of being held in a fixed position and against which a member of said control means is capable of coming to bear, as long as the fluid of said first chamber is under pressure, said member being located in a position corresponding to a position of said first control means located between said first position and said second position. In this way, maintaining the movable stop in a determined position makes it possible to constitute a support for the member of the control means and consequently to block said first control means in a determined position corresponding to a given speed of the pump and therefore at a transport speed of the mortar. Thus, according to this feature, said adjustable blocking means make it possible to maintain the second control means in a fixed position as long as they are activated, and to maintain in said fixed position simultaneously said

  first control means since they are linked together.

  As will be explained in more detail in the description below,

  said member is capable of being formed by the end of the rod of the jack.

  According to a particularly advantageous embodiment of the invention, said control means comprise return means capable of driving said first control means into said first equilibrium position when said first chamber is no longer under pressure. In this way, when the jack is no longer under pressure, the first control means return to their first equilibrium position corresponding to a zero flow rate of the hydraulic pump and by

  Consequently, the Moineau pump and the transport of the concrete stopped.

  Advantageously, said cylinder is a pneumatic cylinder supplied with air and said third control means release the air pressure in said first chamber when said third control means, connected to said compressed air circuit, are at pressure P2 greater than Pl. Thus, thanks to this characteristic, the compressed air produced by a single source makes it possible both to supply air to spray the concrete or the mortar against a wall and to control the setting in

  operation of the variable flow Moineau pump.

  According to a particularly advantageous embodiment of the invention, said first control means can also be actuated in a third position, opposite to said second position from said first equilibrium position, said third position corresponding to the reverse drive of said pump for sucking concrete from said piping, and in that said cylinder is a double-acting cylinder whose rod is capable of controlling said first control means to actuate them towards said third position when the fluid the second bedroom, opposite the

  first bedroom, is under pressure.

  Thus, the jack whose rod is capable of being actuated in translation in two opposite directions, by simply reversing the control of the distributor, can drive said first control means, either in said fixed position corresponding to the mode of transport of the concrete in the piping, or in said third position corresponding to the reverse drive of the sparrow pump and to the decompression of the piping. As will be explained in more detail in

  following the description, the distributor order to the second

  chamber is achieved by means of a manual position hold control. In a first embodiment of the invention, according to the previous embodiment, said cylinder has a double through rod, a first end of said double rod being connected to said first control means and the second end of said double rod free being capable of coming to bear against said movable stop in translation. In this way, when the rod of the jack is driven so that the second free end comes to bear against said stop, the first end simultaneously drives, in the same direction, said first control means in a fixed position located between

  said first position and said intermediate position.

  In a second embodiment, said actuator has a simple rod whose end is capable of coming to bear against said movable stop in translation and whose said end is connected to the first end of a lever mounted to pivot around its center and the second end of which is connected to said first control means. Thus, when the rod of the jack is driven so that its free end comes to bear against said stop, said end simultaneously drives, in the same direction, said lever, the second opposite end of which simultaneously drives in a direction opposite to the direction of driving said free end said first control means in a fixed position located between said

  first position and said intermediate position.

  Preferably, said third control means comprise an indirect control by pilot distributor by pressure increase making it possible to release the compressed air from the first chamber when the compressed air pressure reaches P2 in the circuit. Other features and advantages of the invention will become apparent from the

  reading of the description given below of particular embodiments

  of the invention, given as an indication but not limiting, with reference to the accompanying drawings in which: - Figure 1 is a partial schematic view illustrating the invention according to a first embodiment; - Figure 2 is a partial schematic view illustrating the invention according to a second embodiment; and - Figure 3 is a schematic view showing the entire control system according to the second embodiment illustrated on

Figure 2.

  Figure 1 shows, according to a first embodiment of the invention and, schematically, first control means, in particular consisting of a hydraulic pump 18, comprising a piston 12 capable of being driven in translation in two opposite directions according to arrows F and G. The hydraulic pump 18 is mounted on a machine for spraying concrete or mortar not shown, which includes a concrete receiving hopper. The hopper has an outlet orifice to which is connected a Moineau pump extended by a pipe and which the hydraulic pump 18 makes it possible to drive in rotation. The end of the piping includes a lance supplied with compressed air to project the

concrete or mortar.

  The piston 12 has a groove 14 in which the end of a control lever 16 is capable of coming to engage, said lever making it possible to tilt a turntable against which the pumping pistons are supported. The piston 12 is held at a first end 20 by elastically deformable means 22 allowing, at equilibrium, to maintain the piston 12 and the end of the lever 16 in a position corresponding to the stopping of the circulation of fluids. Thus the angular displacement of the lever 16 makes it possible to vary the fluid flow rate of the hydraulic pump 18 to vary the speed of rotation of the sparrow pump not shown. The speed of rotation of the Moineau pump determines the speed of progression of the concrete or mortar in the piping that extends it. In this way, the displacement of the piston in translation according to arrow F, is capable of driving the lever 16 in position 24, corresponding to the drive of the pump in a first direction capable of pumping concrete or mortar and propel it into the

piping towards its end.

  The piston 12 is connected at its second end 26 to the end 28 of the double rod 30 of a double-acting cylinder 32. The double rod 30 extends through the body of the cylinder 32 between the end 28 connected to the piston 12 and a free end 34 capable of coming to bear against

adjusting means 36.

  The adjustment means 36 comprise a rod 38, a threaded portion of which can be screwed through a nut 40, held in a fixed position. The threaded rod has an end 42 forming a stop against which the free end 34 of the double rod 30 is capable of bearing and an end 44 forming a wheel making it possible to drive the rod 38 in rotation and therefore in translation and thus achieve the adjustment of the pump rotation speed. Indeed, the rod 38, the double rod 30 and the piston 12 being arranged along the same axis, it is understood that the rotation of the dial 44 makes it possible to adjust in a variable fixed position, along the axis of the rods and of the piston 12 , the end 42 forming a stop. Thus, the free end 34 has a stroke limited by the end 42, and allows a corresponding displacement in translation of the end of the double rod 30. Consequently, the displacement of the piston 12 which is itself limited causes the lever according to an angular offset which is entirely determined by the position of the means of

setting 36.

  The cylinder 32 is implemented by means of a distributor 46 which, when controlled in the operating mode corresponding to the projection of the concrete, increases the fluid pressure in the cavity 48 of the cylinder 32 by means of the circuit 49 and decreases it in the cavity 50 via the circuit 51 so as to drive the free end 34

  resting against the end 42 of the rod 38.

  Conversely, the jack 32 is capable of being implemented, thanks to the distributor 46, in an operating mode corresponding to the suction of the concrete from the piping. To do this, the distributor which also makes it possible to increase the fluid pressure in the cavity 50 and to decrease it in the cavity 48, induces the displacement of the double rod in a direction opposite to the end 42 forming a stop and consequently the displacement in translation of the piston 12 according to the arrow G. In this way, the displacement of the piston 12 in translation according to the arrow G, is capable of driving the lever 16 in the position 52, corresponding to the drive of the sparrow pump in a second direction of rotation, opposite to the first, so as to pump the concrete contained in the

  piping to discharge it into the hopper.

  We will explain in more detail the ordering mode of the distributor

  in the following description with reference to Figure 3.

  We will now refer to Figure 2 to describe the invention

  according to a second mode of implementation.

  This FIG. 2 shows a hydraulic pump 118 capable of being controlled by a lever 116, which is capable of being driven between a first operating position 124, corresponding to the pumping of concrete or mortar and a second stop position or

  suction 152 corresponding to the decompression of the piping.

  The lever 116 is capable of being driven in translation by a piston 112 according to an arrow F for the projection mode and an arrow G

for stop mode.

  The piston 112 is driven in translation by means of a double-acting cylinder 132 comprising a single rod 130 by means of a lever 113 arranged substantially perpendicular to the single rod 130 and to the piston 112, the cylinder 132 and the means 110 being spaced from each other. The lever 113 is pivotally mounted around an axis, and its first end 117 is connected to the end 134 of the single rod 130 by means of an oblong hole system perpendicular to the single rod 130 in order to allow relative movement of the simple rod and of the lever 113. The second end 119 of the lever 113 is connected to the second end 126 of the piston 112 by means of a link 121 to allow the relative movement of the second end of the

  piston 126 and the second end 119.

  In addition, the system comprises adjustment means 136, which comprise a rod 138, a threaded portion of which can be screwed through nut means 140 kept in a fixed position. The threaded rod has an end 142 forming a stop against which the end 134 of the simple rod 130 is capable of bearing and an end 144 forming a knurling wheel which makes it possible to drive the rod 138 in rotation and consequently in translation and thus to achieve the

  adjustment of the pump rotation speed.

  The double-acting cylinder 132 is implemented by means of a distributor 146 which, when controlled in the operating mode corresponding to the projection of the concrete, increases the fluid pressure in the cavity 148 of the cylinder 132 by the through circuit 149 and decreases it in cavity 150 through circuit 151 so that

  drive the end 134 in abutment against the end 142 of the rod 138.

  The control mode of the jack 132 is comparable in all respects

  to that of the jack 32 according to the first embodiment.

  When the compressed air is released into the lance, the fluid pressure increases in the chamber 148 and the end 134 of the simple rod bears against the end 142 forming a stop. In this way, the lever 113 pivots and drives the piston 112 in the direction of the arrow F, which itself drives the lever 116 to actuate the pump in rotation in

  the method of spraying concrete or mortar.

  When the compressed air is cut, the simple rod 130 of the jack 132 is free because the elastically deformable means 122 make it possible to

  position the lever 116 in a neutral position.

  Reference will now be made to FIG. 3 to describe in more detail the control means of the jack 132 and of the system illustrated in FIG. 2. Obviously, identical control means are

  likely to be used for the system illustrated in Figure 1.

  This Figure 3 shows the distributor 146 with three positions corresponding to the pressurization of the chamber 148 or the pressurization of the chamber 150 or even to the atmospheric pressure of the two chambers. The distributor 146 has a position 160 holding control corresponding to the three aforementioned positions. The distributor 146 is supplied by a pneumatic power source by means of a compressor 162 via a first circuit 164 forming a first supply part at a pressure PO at least greater than two bars, for example. The first circuit 164 comprises means for bringing the atmospheric pressure 166 capable of being

  activated by any safety device located on said spraying machine.

  In this way, when an operator inadvertently activates any safety device, the distributor 146 is deactivated so that the chambers 150 and 148 are at atmospheric pressure and the hydraulic pump 118

stopped.

  The compressed air supply to the lance of the piping is carried out by a second circuit 168 forming a second part, which is separated from the first circuit 164 by a regulator or nozzle 170 which makes it possible to maintain it at the pressure PO, for example substantially better than

  two bars, when the second circuit 168 is in the open air.

  Advantageously, the circuit 168 includes a safety valve 172 in the event of overpressure. The second circuit 168 is terminated by the projection lance located at the end of the piping and it is likely to be

closed by a valve 174.

  Thus, when the valve is open, the concrete or the mortar is conveyed in the piping to the lance and it is projected by the compressed air which flows therein at a pressure Pl, for example less than substantially 2 bars, the pressure of the first circuit 164 always remaining at a pressure substantially greater than 2 bars to ensure control

cylinder 132.

  The control means comprise a third circuit 176 comprising a pilot relay 178 and ending with a pilot distributor which constitutes an indirect control. The third circuit 176 connects the second circuit 168 and the circuit 149 which directly supplies the

  room 148, by the pilot distributor 180.

  In this way, when the valve 174 is closed, the pressure in the circuit 168 increases at a pressure P2, for example greater than 2 bars, and makes it possible to activate the pilot relay 178 of the third circuit 176, which controls the pilot distributor 180 which puts the circuit 149 of the chamber 148 at atmospheric pressure. Thus, the pressure in the chambers 150 and 148 of the jack 132 are equivalent, and the piston 112 of the control means 110 returns to the position of equilibrium thanks to the means

elastically deformable 122.

  The position 160 control command puts the chamber 150 under pressure, which allows, by reversing the circulation of the hydraulic fluid, to drive the Moineau pump in the opposite direction and to

decompress the piping.

  A characteristic of the invention appears better thanks to the

  detailed description and it resides in the training mode of

  pump control means by means of a jack whose rod is capable of coming to bear against an adjustable stop. As long as the fluid pressure is effective, the cylinder rod presses against the stop by force and the control lever is held in a fixed position, this position corresponding to a determined speed of rotation of the pump and consequently of the flow of the concrete in the piping. As soon as the compressed air circuit is closed and the air no longer flows into the lance, the compressed air pressure increases in the circuit and it causes the release of the second control means. The end of the cylinder rod then ceases to bear against the adjustable stop, and the pump

hydraulic stops.

Claims (9)

  1. Control system for a variable-flow pump, in particular for a Moineau pump, for a machine for spraying concrete or mortar, said pump being extended by piping terminated by a lance in which compressed air via a circuit is capable of '' be injected to spray concrete or mortar, said pump being capable of being controlled by first control means, which can be actuated between a first equilibrium position corresponding to the stopping of the pump and a second position corresponding to a maximum speed of transport of the concrete in said piping, the intermediate positions located between the first and the second position corresponding to intermediate speeds of transport of the concrete, characterized in that it comprises: second control means kinematically connected to said first means control and capable of actuating them towards said second position; - Adjustment blocking means capable of causing the blocking of said first control means between said second position and said first equilibrium position so as to maintain said first control means in a fixed position corresponding to a determined speed of transport of the concrete; and - third control means connected to the compressed air circuit capable of controlling said second control means so that: when the compressed air delivers at a pressure P1 in the lance, said second control means actuate said first control means toward said second position; and * when the injection of compressed air is cut off, the compressed air reaching a pressure P2> P1 in the circuit, said second control means actuate said first means of   control in said equilibrium position.   2. Control system according to claim 1, characterized in that said second control means comprise a jack supplied by a distributor, the rod of which is capable of controlling said first control means to actuate them towards said second position as long as the fluid a first chamber of said cylinder is under pressure.   3. Control system according to claim 2, characterized in that said adjustable locking means consist of a stop movable in translation, capable of being held in a fixed position and against which a member of said control means is likely to come in support, as long as the fluid of said first chamber is under pressure, said member being located in a position corresponding to a position of said first control means located between said   first position and said second position.   4. Control system according to claim 2 or 3, characterized in that said control means comprise return means capable of driving said first control means in said first equilibrium position when said   first bedroom is no longer under pressure.   5. Control system according to any one of claims 2 to 4, characterized in that said cylinder is a pneumatic cylinder   supplied with air and in that said third control means release the air pressure in said first chamber when said third control means, connected to said compressed air circuit,   are at pressure P2 greater than Pl.   6. Control system according to claim 5, characterized in that said compressed air circuit comprises two parts, a first supply part whose pressure PO is at least greater than Pl and a second part connected to said lance, said parts being separated by regulator means capable of maintaining said first   circuit at pressure PO when said second circuit is pressure Pl.   7. Control system according to any one of claims 2 to 6, characterized in that said first control means   are, moreover, operable in a third position, opposite to said second position from said first equilibrium position, said third position corresponding to the reverse drive of said pump making it possible to suck the concrete from said piping, and in that said cylinder is a double-acting cylinder whose rod is capable of controlling said first control means for actuating them towards said third position when the fluid of the second chamber, opposite to the   first bedroom, is under pressure.   8. Control system according to claim 7, characterized in that said cylinder has a double through rod, a first end of said double rod being connected to said first control means and the second end of said free double rod being   likely to bear against said movable stop in translation.   9. Control system according to claim 7, characterized in that said actuator has a single rod whose end is capable of coming to bear against said movable stop in translation and whose said end is connected to the first end of a lever mounted pivoting around its center and the second end of which is connected   to said first control means.