EP3486483B1 - Pumping system comprising a pneumatic pump and a valve for controlling the compressed gas supply to the pump - Google Patents

Description

The present invention relates to a pumping installation as defined in claim 1, of the type comprising a pneumatic pump for pumping a fluid and a system for supplying the pneumatic pump with compressed gas, the supply system comprising a source of compressed gas and a fluid connection fluidly connecting the source to the pneumatic pump.

The invention also relates to an installation for spraying a coating product onto a surface to be coated, of the type comprising an applicator for spraying the coating product onto the surface to be coated and a pumping installation for pumping the coating product and feeding the applicator with said coating product.

In known coating product spraying installations, for example paint spraying, the applicators, typically constituted by spray guns, are generally supplied with coating product under pressure by a pumping installation. This pumping installation usually includes pneumatic pumps arranged in a dedicated room in the building, commonly known as a "paint kitchen", each pumping a coating product into a clean container.

These pumps are supplied with a compressed gas, generally air, which is used to animate the said pumps with a movement which will allow the suction of the coating product in the container and the discharge of the coating product in a fluid connection. connecting the pump to one of the applicators in the installation. The force provided by the compressed gas is dimensioned to compensate for the pressure losses due to the circulation of the coating product in the pump ducts and the discharge of this coating product, at the desired pressure, towards the applicator.

However, a problem arises when the coating material reservoir is empty. In fact, at this stage, the pump no longer being able to suck in coating product, it defuses itself and, the force provided by the compressed gas no longer meeting the resistance of the coating product, the pump gets carried away, which risks damage its components. This risk is all the greater since, as the pumps are isolated in a specific room, no operator is nearby to react quickly to the runaway of one of the pumps.

To solve this problem, pumps have been proposed equipped with anti-runaway devices, constituted by membranes which lock in the event of strong call in pressurized gas, thereby blocking the supply of pressurized gas. These anti-runaway devices are, however, not very reliable.

Anti-runaway devices independent of the pumps have also been proposed, adapted to cut off the supply of compressed gas to the pumps in the event of runaway of the latter thanks to a complex pneumatic logic. These anti-runaway devices are however very expensive.

Pumping installations comprising such anti-runaway devices are known from US 2016/0377074 , US 5,174,722 and US 4,934,598 .

An objective of the invention is thus to propose an economical and reliable solution capable of limiting the risks of runaway of a coating product pump. Another objective of the invention is to allow the retrofitting of existing installations with the proposed solution.

To this end, the subject of the invention is a pumping installation of the aforementioned type, in which the pumping installation also comprises a system for regulating the supply of compressed air to the pneumatic pump, said regulation system comprising a valve. mounted on the fluidic and switchable link between a blocking state, in which the valve prevents the circulation of compressed gas between the source and the pneumatic pump, and a passing state, in which the valve allows the circulation of compressed gas between the source and the pneumatic pump.

• le système de régulation comprend un système de pilotage automatique de la vanne, ledit système de pilotage automatique comprenant un capteur de surveillance d'un paramètre, et un actionneur agissant sur la vanne pour permuter automatiquement la vanne de son état passant vers son état bloquant en fonction d'un signal produit par le capteur et représentatif du paramètre surveillé,
• le paramètre surveillé est constitué par un état de la pompe pneumatique,
• le capteur est propre à générer un signal électrique prédéterminé lorsqu'il détecte au moins un état prédéterminé de la pompe pneumatique, et l'actionneur est raccordé électriquement au capteur de manière à recevoir ce signal électrique lorsqu'il est généré, l'actionneur étant en outre adapté pour permuter la vanne de son état passant vers son état bloquant lorsqu'il reçoit ce signal électrique,
• l'état prédéterminé comprend un état emballé de la pompe pneumatique,
• la vanne comprend un corps définissant intérieurement un passage pour le gaz comprimé, un clapet monté mobile relativement au corps entre une position fermée, dans laquelle il obture le passage, et une position ouverte, dans laquelle il libère le passage, et un organe de rappel du clapet vers sa position fermée, l'actionneur étant propre à retenir le clapet dans sa position ouverte,
• l'actionneur présente un état actif dans lequel il exerce sur le clapet ouvert une force de retenue du clapet dans sa position ouverte, et un état inactif dans lequel l'actionneur n'exerce pas de force de retenue sur le clapet ouvert,
• l'actionneur est apte à être dans son état actif lorsqu'il n'est pas alimenté en courant électrique, et dans son état inactif lorsqu'il est alimenté en courant électrique,
• l'actionneur comprend une ventouse électromagnétique, en particulier une ventouse électromagnétique à aimant permanent,
• la vanne comprend une contreplaque métallique mobile conjointement avec le clapet de sorte à être plaquée contre la ventouse électromagnétique lorsque le clapet est ouvert, et à être à l'écart de la ventouse électromagnétique lorsque le clapet est fermé, la ventouse électromagnétique étant apte à exercer sur la contreplaque lorsque l'actionneur est dans son état actif une force de sollicitation de la contreplaque vers sa position plaquée, ladite force de sollicitation étant supérieure à la force de rappel lorsque le clapet est ouvert et étant inférieure à la force de rappel lorsque le clapet est fermé,
• le clapet est monté mobile relativement au corps en translation selon une direction longitudinale entre ses positions ouverte et fermée,
• le système de régulation comprend un bouton à actionnement manuel, en particulier un bouton poussoir, pour la permutation de la vanne depuis son état bloquant dans son état passant,
• l'installation de pompage comprend une enceinte de confinement dans laquelle la pompe pneumatique est installée, la vanne étant disposée hors de ladite enceinte de confinement,
• l'installation de pompage comprend un réservoir, en particulier un bidon, contenant le fluide, la pompe pneumatique étant apte à pomper le fluide contenu dans ledit réservoir.

According to particular embodiments of the invention, the installation also has one or more of the following characteristics, taken in isolation or according to any technically possible combination (s):

• the regulation system comprises an automatic piloting system of the valve, said automatic piloting system comprising a sensor for monitoring a parameter, and an actuator acting on the valve to automatically switch the valve from its passing state to its blocking state by function of a signal produced by the sensor and representative of the parameter monitored,
• the monitored parameter consists of a state of the pneumatic pump,
• the sensor is capable of generating a predetermined electrical signal when it detects at least one predetermined state of the pneumatic pump, and the actuator is electrically connected to the sensor so as to receive this electrical signal when it is generated, the actuator being further adapted to switch the valve from its passing state to its blocking state when it receives this electrical signal,
• the predetermined state includes a packed state of the pneumatic pump,
• the valve comprises a body internally defining a passage for the compressed gas, a valve mounted movable relative to the body between a closed position, in which it closes the passage, and an open position, in which it frees the passage, and a member for returning the valve to its closed position, the actuator being capable of retaining the valve in its open position,
• the actuator has an active state in which it exerts on the open valve a retaining force of the valve in its open position, and an inactive state in which the actuator does not exert a retaining force on the open valve,
• the actuator is able to be in its active state when it is not supplied with electric current, and in its inactive state when it is supplied with electric current,
• the actuator comprises an electromagnetic suction cup, in particular an electromagnetic suction cup with permanent magnet,
• the valve comprises a movable metal counterplate jointly with the valve so as to be pressed against the electromagnetic lock when the valve is open, and to be away from the electromagnetic lock when the valve is closed, the electromagnetic lock being able to exert on the counterplate when the actuator is in its active state a biasing force from the counterplate to its pressed position, said biasing force being greater than the restoring force when the valve is open and being less than the restoring force when the valve is closed,
• the valve is mounted movable relative to the body in translation in a longitudinal direction between its open and closed positions,
• the regulation system comprises a manually actuated button, in particular a push button, for switching the valve from its blocking state to its on state,
• the pumping installation comprises a containment enclosure in which the pneumatic pump is installed, the valve being disposed outside said containment enclosure,
• the pumping installation comprises a reservoir, in particular a canister, containing the fluid, the pneumatic pump being able to pump the fluid contained in said reservoir.

The invention also relates to an installation for spraying a coating product onto a surface to be coated, of the aforementioned type, in which the pumping installation is constituted by a pumping installation as defined above.

• la Figure 1 est une vue schématique d'une installation de projection selon l'invention ;
• la Figure 2 est une vue en coupe d'une vanne de l'installation de projection de la Figure 1, la vanne étant dans un état passant, et
• la Figure 3 est une vue similaire à celle de la Figure 2, la vanne étant dans un état bloquant.

Other characteristics and advantages of the invention will appear on reading the description which follows, given solely by way of example and made with reference to the appended drawings, in which:

• the Figure 1 is a schematic view of a projection installation according to the invention;
• the Figure 2 is a sectional view of a valve of the projection installation of the Figure 1 , the valve being in a passing state, and
• the Figure 3 is a view similar to that of the Figure 2 , the valve being in a blocking state.

The projection installation 10 shown in the Figure 1 is intended for spraying a fluid coating product 12, typically a paint, onto a surface to be coated (not shown). To this end, the spraying installation 10 comprises an applicator 14 for applying the coating product 12 to the surface to be coated, a pumping installation 16 for pumping the coating product 12, and a fluid connection 18 fluidly connecting the pumping installation 16 to the applicator 14 for supplying the applicator 14 with the coating product pumped by the pumping installation 16.

The applicator 14 is typically constituted by a spray gun. It comprises an inlet 19 for supplying a coating product, fluidly connected to the fluid connection 18.

The pumping installation 16 comprises a tank 20 containing the coating product 12, a pneumatic pump 22 for pumping the coating product 12 contained in the tank 20, and a system 24 for supplying the pneumatic pump 22 with compressed gas. The pumping installation 16 also includes a confinement enclosure 25 in which the reservoir 20 and the pump 22 are arranged.

The reservoir 20 is typically constituted by a container.

The pneumatic pump 22 comprises, in known manner, a probe 26 inserted in the reservoir 20 and defining an orifice 28 for suction of the coating product 12, an orifice 30 for discharging the coating product 12, fluidly connected to the fluid connection 18 , a pneumatic motor (not shown) drawing its power from the expansion of a compressed gas and capable of driving the movement of pumping members (not shown) to suck the coating product 12 through the suction port 28 and discharge it towards the discharge orifice 30, and, typically, a system (not shown) for controlling the reversal of the displacement of the pneumatic motor. The pneumatic pump 22 also includes a supply orifice 32 for supplying the pump 22 with compressed gas.

The system for controlling the displacement of the pneumatic motor comprises for example a distributor for alternately supplying two cavities of the motor with compressed gas so as to cause a reciprocating movement of the pneumatic motor, and sensors for the end of race to detect when the engine is coming in end of movement and, in response, order the distributor to change the motor cavity supplied with compressed gas.

The supply system 24 comprises a source 34 of compressed gas, a fluid connection 36 fluidly connecting the source 34 to the supply port 32 of the pump 22, and a system 38 for regulating the supply of the pump 22 in compressed gas.

The source 34 is able to supply a compressed gas, for example compressed air. To this end, the source 34 is typically constituted by a compressor, in particular an air compressor.

The regulation system 38 comprises a valve 40 mounted on the fluid link 36, outside the enclosure 25, said valve 40 being switchable between a blocking state, in which it prevents the circulation of compressed gas between the source 34 and the pneumatic pump. 32, and a passing state, in which it allows the circulation of compressed gas between the source 34 and the pneumatic pump 32. The regulation system 38 also includes a system 42 for automatic control of the valve 40.

The fluid link 36 comprises an upstream section 37 between the source 34 and the valve 40, and a downstream section 39 between the valve 40 and the pump 22.

With reference to the Figure 2 , the valve 40 comprises a body 44 internally defining a passage 46 for the compressed gas, and a valve 48 movably mounted relative to the body 44 between a closed position, in which it closes the passage 46, and an open position, in which it releases the passage 46, the open position of the valve 48 corresponding to the passing state of the valve 40, and the closed position of the valve 48 corresponding to the blocking state of the passage 46. The valve 40 further comprises a member 50 for returning the valve 48 to its closed position.

The passage 46 is through and opens outside the body 44 by an upstream orifice 52 fluidly connected to the upstream section 37 of the fluid connection 36, and by a downstream orifice 54 fluidly connected to the downstream section 39 of the fluid connection 36. It has an upstream section 56, opening outside the body 44 through the upstream opening 52, and a downstream section 58, opening outside the body 44 through the downstream opening 54.

In the example shown, the upstream section 56 comprises a first straight channel 60, oriented in a transverse direction T, and a second straight channel 62, oriented in a longitudinal direction L perpendicular to the transverse direction T. The downstream section 58 comprises quant a third rectilinear channel 64 oriented in the transverse direction T, a cavity 66 disposed longitudinally in the extension of the second channel 62, of cross section greater than that of the second channel 62, and a fluid connection 68 between the third channel 64 cavity 66. The first channel 60 opens out of the body 44 through the upstream port 52, and the third channel 64 opens out of the body 44 through the downstream port 54.

The second channel 62 opens into the cavity 66 and outside the body 44.

The body 44 also defines, at the junction between the upstream 56 and downstream 58 sections, a seat 70 for the valve 48 in the closed position. This seat 70 is, in the example shown, formed by a shoulder surrounding the orifice through which the second channel 62 opens into the cavity 66.

The valve 48 is mounted movable in translation in the longitudinal direction L relative to the body 44 between its open and closed positions. To this end, the valve 48 is, in the example shown, secured to a shaft 72 engaged in the second channel 62, said shaft 72 comprising a narrow section 74, of cross section less than 90% of that of the second channel 62 , and a wide section 76, of cross section substantially complementary to that of the second channel 62: the shaft 72 thus forms with the second channel 62 a guide for guiding in translation the valve 48 relative to the body 44.

The narrow section 74 is in particular interposed between the valve 48 and the wide section 76, the wide section 76 being at a distance from the valve 48 greater than the distance from the valve 48 to the first channel 60 when the valve 48 is in the open position, as visible on the Figure 2 . Thus, the first channel 60 is not blocked by the wide section 76 when the valve 48 is open.

A seal 78 is disposed around the wide section 76, between said wide section 76 and the wall of the second channel 62. This prevents compressed gas from leaking out of the body 44 through the end by which the second channel 62 opens out of the body 44.

The valve 48 comprises an annular seal 80. This annular seal 80 defines a face 82 for supporting the valve 48 against the seat 70 when the valve 48 is closed.

In the example shown, the valve 48 is housed inside the cavity 66.

The return member 50 is, in the example shown, formed by a compression spring housed in the cavity 66, between the valve 48 and a bottom 84 of the cavity 66.

Still referring to the Figure 2 , the valve 40 also comprises a metal counterplate 86 disposed outside the body 44 and movable jointly with the valve 48 so as to occupy a position close to the body 44 when the valve 48 is closed and a position away from the body 44 when the valve 48 is open.

The counter plate 86 is aligned longitudinally with the valve 48, the valve 48 being interposed between the seat 70 and said counter plate 86.

The counterplate 86 is in particular integral in translation with the valve 48. To this end, it is, in the example shown, made in one piece with a shaft 87 mounted, typically screwed, on the shaft 72, and extending through an opening 88 opening into the bottom 84 of the cavity 66 and outside the body 44. In particular, a seal 89 surrounds said shaft 87 in the opening 88 and provides sealing between the cavity 66 and the outside of the body 44.

Back to the Figure 1 , the automatic pilot system 42 comprises a sensor 90 for monitoring a parameter, and an actuator 92 ( Figure 2 ) acting on the valve 40 to automatically switch the valve 40 from its passing state to its blocking state as a function of a signal produced by the sensor 90 and representative of the parameter monitored.

The sensor 90 comprises a first part 94 arranged in the confinement enclosure 25, and a second part 96 disposed outside of the confinement enclosure 25.

The first part 94 is capable of occupying a first state in normal time, and a second state when the monitored parameter verifies a predetermined condition, said second state being specific to the case in which said predetermined condition is verified.

The monitored parameter is here constituted by a state of the pump 22. The predetermined condition is then that the state of the pump 22 is a predetermined state, typically constituted by a packed state of the pump 22.

• un niveau du produit de revêtement 12 contenu dans le réservoir 20, la condition prédéterminée étant que ce niveau soit inférieur à une valeur prédéterminée,
• un paramètre représentatif d'un niveau de fuite du produit de revêtement 12 au niveau du moteur de la pompe 22, notamment un paramètre représentatif d'un niveau de rendement de la pompe 22, comme par exemple un rapport entre le flux de produit 12 sortant de la pompe 22 et le flux de produit 12 entrant, la condition prédéterminée étant que ce rapport soit inférieur à une valeur prédéterminée, ou
• un paramètre représentatif d'un niveau de fuite pneumatique au niveau du moteur de la pompe 22, comme par exemple le débit d'air consommé par ladite pompe 22, la condition prédéterminée étant que ce débit soit inférieur à une valeur prédéterminée.

As a variant, the monitored parameter consists of:

• a level of the coating product 12 contained in the reservoir 20, the predetermined condition being that this level is less than a predetermined value,
• a parameter representative of a level of leakage of the coating product 12 at the level of the motor of the pump 22, in particular a parameter representative of a level of efficiency of the pump 22, such as for example a ratio between the flow of product 12 leaving of the pump 22 and the incoming product flow 12, the predetermined condition being that this ratio is less than a predetermined value, or
• a parameter representative of a level of pneumatic leakage at the level of the pump 22 motor, such as for example the air flow consumed by said pump 22, the predetermined condition being that this flow is less than a predetermined value.

The second part 96 is suitable for generating an electrical signal when the first part 94 is in its second state, and exclusively when said first part 94 is in its second state. Thus, the second part 96 is suitable for generating an electrical signal when the predetermined condition is verified, and exclusively when it is verified.

The actuator 92 is electrically connected to the sensor 90 so as to receive said electrical signal when it is generated. To this end, an electrical connection 98 electrically connects the actuator 92 to the sensor 90.

With reference to the Figure 2 , the actuator 92 consists of an electromagnetic suction cup, in particular an electromagnetic suction cup with permanent magnet, aligned longitudinally with the counterplate 86, the counterplate 86 being interposed between the valve 48 and the suction cup, said suction cup being arranged so that, when the valve 48 is in the open position, the counterplate 86 is pressed against said suction cup and that, when the valve 48 is in the closed position, the counterplate 86 is away from said suction cup.

The actuator 92 thus has, in the absence of electric current, an active state in which it exerts on the plywood 86 a magnetic force for biasing the plywood 86 towards its position pressed against the actuator 92 and, when it is supplied with electric current an inactive state in which it does not exert such a biasing force on the counterplate 86.

The return member 50 and the magnetizing force of the actuator 92 are dimensioned so that, when the counterplate 86 is pressed against the actuator 92, the biasing force exerted by the actuator 92 on the latter is greater to the return force of the return member 50. The actuator 92 is thus able to retain the valve 48 in its open position, the biasing force forming, when the valve 48 is in the open position, a retaining force of the valve 48 in the open position.

Furthermore, due to the cancellation of this retaining force when the actuator 92 is supplied with electric current, therefore typically when it receives the electric signal generated by the second part 96 of the sensor 90, the cancellation of this force retainer automatically causing the valve 48 to move to its closed position under the effect of the only force continuing to apply to said valve 48, namely the restoring force of the member 50, the actuator 92 is suitable for automatically switch the valve 40 from its passing state to its blocking state when it receives the electrical signal generated by the second part 96 of the sensor 90.

The return member 50 and the magnetizing force of the actuator 92 are also dimensioned so that, when the valve 48 is closed, the biasing force exerted by the actuator 92 on the counterplate 86 is less than the force of return of the return member 50. Thus, the actuator 92 is not able to move the valve 48 from its closed position to its open position.

In order to allow the valve 48 to return to the open position, the regulation system 38 also includes, as visible on the Figure 2 , a button 100 with manual actuation for switching the valve 40 from its blocking state to its on state. This button 100 is in particular formed by a push button aligned longitudinally with the valve 48, the seat 70 being interposed between the valve 48 and said button 100. Thus, a simple press on the button 100 causes the valve 48 to move to the away from the seat 70 and, in this way, makes it possible to return the valve 48 to its open position.

Thanks to the invention described above, it is thus possible to avoid any risk of runaway of the pump 22, the latter no longer being supplied with compressed gas as soon as it begins to run away. This objective is achieved first of all economically, the regulation system 38 being of simple design, but also reliably, since the permutation of the valve 40 in its blocking state is done without risk of blocking.

Furthermore, the invention allows easy and economical retrofitting of existing installations, since it suffices to install the regulation system 38 therein.

Claims (11)

1. Pumping installation (16) comprising a pneumatic pump (22) for pumping a fluid (12) and a supply system (24) for supplying the pneumatic pump (22) with compressed gas, the supply system (24) comprising a source (34) of compressed gas and a fluidic connection (36) that fluidly connects the source (34) to the pneumatic pump (22), the pumping installation (16) also comprising a control system (38) for controlling the supply of compressed gas to the pneumatic pump (22), said control system (38) comprising:

   - a valve (40) mounted on the fluidic connection (36) and switchable between a blocking state, in which the valve (40) prevents the flow of compressed gas between the source (34) and the pneumatic pump (22), and a passing state, in which the valve (40) allows the flow of compressed gas between the source (34) and the pneumatic pump (22), the valve (40) comprising a body (44) internally defining a passage (46) for the compressed gas, a valve (48) mounted to move relative to the body (44) between a closed position, in which it closes the passage (46), and an open position, in which it releases the passage (46), and a member (50) for restoring the valve (48) to its closed position, and

   - an automatic control system (42) for automatic control of the valve (40), said automatic control system (42) comprises a sensor (90) for monitoring a parameter, and an actuator (92) acting on the valve (40) to automatically switch the valve (40) from its passing state to its blocking state as a function of a signal produced by the sensor (90) and representative of the parameter being monitored, the actuator (92) being designed to retain the valve (48) in its open position, the actuator (92) having an active state in which it exerts on the open valve (48) a force retaining the valve (48) in its open position and an inactive state in which the actuator (92) does not exert a retaining force on the open valve (48),
   characterized in that the actuator (92) is designed to be in its active state when it is not supplied with electric current, and in its inactive state when is supplied with electric current.
2. Pumping installation (16) according to claim 1, wherein the monitored parameter is a state of the pneumatic pump (22).
3. Pumping installation (16) according to claim 2, wherein the sensor (90) is designed to generate a predetermined electrical signal when it detects at least one predetermined state of the pneumatic pump (22), and the actuator (92) is electrically connected to the sensor (90) to receive this electrical signal when it is generated, the actuator (92) being further designed to switch the valve (40) from its passing state to its blocking state when it receives this electrical signal.
4. Pumping installation (16) according to claim 3, wherein the predetermined state comprises a runaway state of the pneumatic pump (22).
5. Pumping installation (16) according to any one of the preceding claims, wherein the actuator (92) comprises an electromagnetic lock, in particular a permanent magnet electromagnetic lock.
6. Pumping installation (16) according to claim 5, wherein the valve (40) comprises a metal counterplate (86) that is movable together with the valve (48) in order to be pressed against the electromagnetic lock when the valve (48) is open, and to be away from the electromagnetic lock when the valve (48) is closed, the electromagnetic plunger being able to exert on the counterplate (86), when the actuator (92) is in its active state, a biasing force of the counterplate (86) towards its pressed position, said biasing force being greater than the restoring force when the valve (48) is open, and is less than the restoring force when the valve (48) is closed.
7. Pumping installation (16) according to any one of the preceding claims, wherein the valve (48) is mounted to move in translation relative to the body (44) in a longitudinal direction (L) between its open and closed positions.
8. Pumping installation (16) according to any one of the preceding claims, wherein the control system (38) comprises a manually operated button (100), in particular a push button, for switching the valve (40) from its blocking state in its passing state.
9. Pumping installation (16) according to any one of the preceding claims, comprising a containment enclosure (25) in which the pneumatic pump (22) is installed, the valve (40) being arranged outside the confinement enclosure (25).
10. Pumping installation (16) according to any one of the preceding claims, comprising a reservoir (20), in particular a can, containing the fluid (12), the pneumatic pump (22) being able to pump the fluid (12) contained in the reservoir (20).
11. Installation (10) for spraying a coating product onto a surface to be coated, comprising an applicator (14) for spraying the coating product onto the surface to be coated, and a pumping installation (16) according to the invention according to any one of the preceding claims for pumping the coating product and supplying the applicator (14) with the coating product.

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