EP3440353B1 - Proportional metering pump, method for assembling and disassembling such a pump - Google Patents

Description

The invention relates to a proportional metering pump of the type comprising a hydraulic machine supplied with a main liquid and with a secondary liquid, and a mechanism for metering the secondary liquid. The invention also relates to a method of mounting and dismounting the metering mechanism with the hydraulic machine.

It is known to assemble the metering mechanism with the hydraulic machine by means of a ring mounted to rotate freely on a nozzle of the metering mechanism. The assembly is carried out by directly screwing the ring onto a thread made around the entry into a cavity inside the hydraulic machine.

Generally this interior cavity is a chamber for mixing the main liquid with the secondary liquid upstream from the outlet of the hydraulic machine. This interior cavity is also crossed by a plunger actuated by a member of the hydraulic machine capable of performing an alternating movement, said movement being communicated to the plunger and causing the aspiration of the secondary liquid through the metering mechanism, into the interior cavity. , if the latter acts as a mixing chamber.

However, this type of assembly can however be subject to handling errors or unintentional unscrewing. This type of fault then has a drawback for the user, which results in a loss of the main liquid (generally water). This type of fault also presents a significant risk of leakage of the secondary liquid when the unscrewing is partial, which can lead to pollution of the site hosting the pump (the secondary liquid is generally a chemical such as fertilizer for planting or well an animal medicine).

So the document FR 2 967 218 A1 describes a proportional diaphragm metering device comprising means for fixing the nozzle to the tubing for access to the interior cavity of the metering device, said means comprising a fixing ring provided with a first and a second end, and mounted in rotation around one end of the nozzle. However, this assembly does not have a locking ring, and therefore remains exposed to the risks of unscrewing.

Likewise, the document FR 2 681 646 A1 concerns an adjustable displacement pump by means of a sleeve whose stroke can be blocked with a tightening nut. This device does not however have two rings cooperating at the end of screwing so that one of them blocks the unscrewing of the other.

This is why, the object of the invention is to overcome all or part of the drawbacks set out above by proposing a proportional metering pump comprising a metering mechanism as well as a hydraulic machine, and an assembly and disassembly method, preventing involuntary separation between the nozzle of the dosing mechanism and the hydraulic machine.

• une bague de fixation dotée d'une première et d'une seconde extrémité, et montée en rotation autour de l'une des extrémités de l'ajutage,
• une bague de blocage dotée d'une première et d'une seconde extrémité, et montée en translation suivant l'axe de la machine hydraulique le long de la tubulure d'accès à la chambre de mélange, la première extrémité de ladite bague étant plaquée en direction du mécanisme de dosage contre un épaulement ménagé sur ladite tubulure d'accès au moyen d'un ressort,

la bague de fixation et la tubulure d'accès à la cavité intérieure à la machine hydraulique étant apte à coopérer suivant un vissage à la fin duquel la seconde extrémité de la bague de blocage est solidarisée en rotation par complémentarité de forme avec la seconde extrémité de la bague de fixation, de manière à verrouiller le dévissage de la bague de fixation.More particularly, the subject of the invention is a proportional metering pump comprising a hydraulic machine provided with an inlet and an outlet, a metering mechanism provided with a suction nozzle provided with a suction valve and communicating at one of its ends with a tubing for access to a cavity inside the pump and at the other of its ends with a reservoir of product to be dosed, the hydraulic machine extending along a longitudinal axis and containing a organ capable of performing a reciprocating movement, the supply of liquid to the input pump triggering the reciprocating movement of said organ, which movement alternately causing suction through the nozzle into the interior cavity with opening of the suction valve when the the member moves away from the nozzle then an expulsion at the outlet of the pump with closing of the suction valve when the member approaches the nozzle, characterized in that the pump also comprises means for fixing the nozzle to the tubing for access to the interior cavity to the hydraulic machine, said means comprising:

• a fixing ring provided with a first and a second end, and mounted in rotation around one of the ends of the nozzle,
• a locking ring provided with a first and a second end, and mounted in translation along the axis of the hydraulic machine along the tubing for access to the mixing chamber, the first end of said ring being plated in the direction of the metering mechanism against a shoulder formed on said access tube by means of a spring,

the fixing ring and the tubing for access to the cavity inside the hydraulic machine being able to cooperate according to a screwing at the end of which the second end of the locking ring is secured in rotation by form complementarity with the second end of the fixing ring, so as to lock the unscrewing of the fixing ring.

Optional, complementary or alternative features of the invention are set out below.

The screwing is preferably less than half a turn.

The fixing ring may include at its second end and at its inner circumferential surface a male multi-start thread consisting of two to eight threads extending along the same helix, the tubing for access to the cavity inside the hydraulic machine with additional female thread.

In the case of a multi-start male thread, the latter can be made up of four threads extending over a length corresponding to a screwing along an eighth of a turn.

The tubing for access to the cavity inside the hydraulic machine may comprise a multi-start male thread consisting of two to eight threads extending along the same helix, the fixing ring being provided at its second end and at its level. inner circumferential surface of a complementary female thread.

The male multi-start threading of the tubing can then consist of four threads extending over a length corresponding to a screwing in an eighth of a turn.

The tubing for access to the cavity inside the hydraulic machine and the fixing ring can cooperate in screwing according to a configuration of the bayonet type, one of the tubing for access to the interior cavity and fixing ring being provided with at least one lug capable of blocking in a groove formed on the other of the tubing for access to the interior cavity and fixing ring.

The second end of the locking ring has tongues capable of occupying the space between portions of increasing height formed on the second end of the fixing ring, said threads being carried by said portions.

The components of the pump are manufactured by injection of thermoplastic plastic materials chosen from the list defined by polyamides, polyvinylidene fluorides, high density polyethylenes, polypropylenes loaded or not, polyformaldehydes.

Sealing means can be interposed between the nozzle and the tubing for access to the mixing chamber.

The invention also relates to a first method of mounting a proportional metering pump according to any one of the embodiments of the invention, characterized in that one proceeds to the screwing of the fixing ring with the tubing for access to the cavity inside the hydraulic machine, until the second end of the locking ring is made to rotate with the second end of the fixing ring by complementary shape, so as to lock the unscrewing of the fixing ring.

According to a preferred characteristic, the screwing is less than half a turn.

The invention also relates to a first method of disassembling a proportional metering pump according to any one of the embodiments of the invention, characterized in that the locking ring is translated so as to distance the first end of said ring of the shoulder against which it was resting, then unscrewing the fixing ring of the tube for access to the interior cavity to the hydraulic machine.

According to a preferred characteristic, the unscrewing is less than half a turn.

• la FIGURE 1 est une représentation schématique d'une pompe à dosage proportionnel utilisant un premier type de machine hydraulique et conforme à un mode de réalisation de l'invention,
• la FIGURE 2 est une représentation schématique d'une pompe à dosage proportionnel utilisant un second type de machine hydraulique et conforme à un mode de réalisation de l'invention,
• la FIGURE 3 est une représentation d'une vue détaillée de l'invention suivant une coupe selon un plan perpendiculaire à l'axe de la pompe.
• les FIGURES 4 et 5 sont des représentations d'une vue détaillée de l'invention suivant des coupes selon l'axe longitudinal de la pompe.
• les FIGURES 6 et 7 sont des vues en perspective de l'invention.

Other advantages and particularities of the invention will appear on reading the detailed description of implementations and embodiments in no way limiting, and the following appended drawings:

• the FIGURE 1 is a schematic representation of a proportional metering pump using a first type of hydraulic machine and in accordance with an embodiment of the invention,
• the FIGURE 2 is a schematic representation of a proportional metering pump using a second type of hydraulic machine and in accordance with an embodiment of the invention,
• the FIGURE 3 is a representation of a detailed view of the invention in a section along a plane perpendicular to the axis of the pump.
• the FIGURES 4 and 5 are representations of a detailed view of the invention according to sections along the longitudinal axis of the pump.
• the FIGURES 6 and 7 are perspective views of the invention.

As the embodiments described below are in no way limiting, it is possible in particular to consider variants of the invention comprising only a selection of described characteristics, isolated from the other described characteristics (even if this selection is isolated within a sentence including these other features), if this selection of features is sufficient to confer a technical advantage or to differentiate the invention from the state of the prior art. This selection includes at least one characteristic, preferably functional, without structural details, or with only part of the structural details if this part only is sufficient to confer a technical advantage or to differentiate the invention from the state of the prior art. .

For the sake of brevity and clarity, the elements have the same references on the different figures.

The figures 1 and 2 each represents an embodiment of a proportional metering pump. It comprises a hydraulic machine 4 extending along a longitudinal axis 9, and provided with an inlet 40, an outlet 41, a tubing for access to an interior cavity 43, as well as a suction nozzle 75 This suction nozzle is provided with a suction valve 80 communicating at one of its ends with a cavity inside the pump (not shown in the figure) and at the other of its ends with a container of product to be vacuumed (not shown in the figure).

The hydraulic machine is provided with an organ capable of performing an alternating movement, the supply of liquid to the pump at the input triggering the reciprocating movement of the organ, which movement alternately causing suction through the nozzle into the cavity. interior with opening of the suction valve 80 when the member moves away from the nozzle 75 then an expulsion at outlet 41 of the pump with closing of the first suction valve when the member approaches the nozzle.

The hydraulic machine can be of the type described in the document EP1971776 A1 and on the figure 1 .

This hydraulic machine comprises an envelope comprising a body and a cover, a separation means capable of reciprocating in the envelope between the body and the cover, this separation means defining two chambers. The hydraulic machine also includes hydraulic switching means for supplying liquid and evacuating the aforementioned chambers. These switching means comprise a distribution member which can take two stable positions and which is controlled by the movements of the separation means. The body of the envelope also contains a compartment connected to a pressurized liquid inlet and in which the switching means are housed, as well as triggering means comprising a pusher linked to the separation means, capable of causing, at the end stroke, a sudden change in the position of the switching means, under the action of an elastic means, for reversing the stroke. The dispensing member comprises a dispensing drawer applied against a fixed flat plate relative to the body of the envelope, the dispensing drawer being able to slide in leaktight fashion, without a seal, against the plate which has orifices connected respectively to the chambers envelope and a liquid outlet port. The drawer is then provided to, depending on its position, close some of the openings or put them in communication with the arrival of fluid or with the exhaust.

The hydraulic machine can also be of the type described in the document EP1971774 A1 and on the figure 2 .

In this case, the hydraulic machine comprises a casing, a piston capable of sliding in reciprocating motion in the casing, the piston separating the casing into two chambers, hydraulic switching means for the supply of liquid and the evacuation of chambers separated by the piston. These switching means are controlled by the movements of the piston and comprise at least one link acting on a dispensing member which can take two stable positions. Triggering means are further provided comprising a pusher capable of causing, at the end of the piston stroke, an abrupt change in the position of the switching means, under the action of an elastic means, for reversing the race. The elastic means is secured, at each of its ends, to an articulation member received respectively in a housing provided on the link and on another movable part of the hydraulic machine, each housing being open in a direction substantially opposite to the direction of the force exerted by the elastic means in the housing, so that each articulation member can be extracted from its housing open against said force.

The proportional metering pump also includes a metering mechanism 7 for adjusting the volume drawn into the nozzle 75. This mechanism is described in figures 1 and 2 and involves an adjustment nut 70 which drives the body of the metering device 73 in its jacket 70. As at top dead center of the hydraulic machine, the plunger 71 and the metering joint 72 leave the body of the metering unit 73, the metering stroke is therefore more or less long. Therefore, the volume sucked is more or less important. The volume of water for a cycle being almost constant, the dosage is therefore more or less strong.

As shown in more detail on figures 3, 4 , 5, 6 and 7 the pump further comprises means for fixing the nozzle 75 to the access pipe 43 to the interior cavity of the hydraulic machine.

These means comprise a fixing ring 2 of substantially annular shape, extending between a first 20 and a second 21 end. This fixing ring is mounted to rotate freely around the end of the nozzle 75 intended to be secured to the pipe 43 of the hydraulic machine 4. This ring can for example be mounted on the nozzle 75, with an internal diameter reduced at its end 20 so that said end abuts against a shoulder formed on the end of the nozzle 75. In this way, the nozzle cannot be disengaged from the fixing ring 2 when the nozzle is fixed to the tubing for access to the interior cavity.

These means also comprise a locking ring 1 also of substantially annular shape, extending between a first 10 and a second 11 end. This fixing ring is mounted fixed in rotation relative to the hydraulic machine and free in translation along the tubing for access to the mixing chamber. This mounting can be achieved by means of ribs and complementary grooves formed respectively on the surface of the tubing and on the circumferential surface inside the locking ring. According to one embodiment, it is therefore possible to provide at least one groove 45 on the outer circumferential surface of the tube 43, capable of accommodating a slider provided on the inner circumferential surface of the locking ring 1.

Spring-forming means 3 maintain, by their return force, the first end 10 of said ring pressed against a shoulder 430 formed on said tube and in the direction of the metering mechanism 7 and of the nozzle 75.

“Spring” is understood to mean any mechanical device designed to store energy when it is deformed and to restore the same amount when it is released. The means 3 can be, for example, a spring of the metal coil or thermoplastic leaf type.

The fixing ring and the tubing for access to the cavity inside the hydraulic machine are able to cooperate according to a screwing. By screwing is meant a displacement in an Euclidean affine space which is the commutative compound of a rotation and a translation along a vector directing the axis of rotation (in this case axis 9). Thus, the assembly of the fixing ring and the tubing must be understood in the broad sense and must not be limited to the mere cooperation of threading between two parts.

Preferably, the screwing is less than half a turn, so that the connection between the fixing ring and the hydraulic machine is carried out quickly.

At the end of the screwing, the second end 11 of the locking ring is secured to the second end 21 of the fixing ring by form complementarity. In other words, the surfaces of the ends 11 and 21 of the rings are nested so as to prevent rotation of one relative to the other. In this way, the unscrewing of the fixing ring is locked.

According to a first embodiment, the fixing ring comprises at its second end 21 and at its inner circumferential surface a male multi-start thread consisting of two to eight threads extending along the same helix. The tubing for access to the cavity inside the hydraulic machine consequently comprises a complementary female thread 44 machined on its outer circumferential surface.

Preferably, the male multi-start thread consists of four threads extending over a length corresponding to a screwing in an eighth of a turn.

The thread can be machined just as it can be injection molded.

According to a variant, the tube 43 for access to the interior cavity of the hydraulic machine comprises on its external circumferential surface a multi-start male thread consisting of two to eight threads extending along the same helix. The fixing ring is then provided, in turn, at its second end 21 and at its inner circumferential surface with a complementary female thread.

Preferably, the male multi-start thread consists of four threads extending over a length corresponding to a screwing in an eighth of a turn.

According to a second embodiment, the tubing for access to the interior cavity of the hydraulic machine and the fixing ring cooperate in screwing according to a configuration of the bayonet type.

According to a first variant, the tubing for access to the inner cavity is provided on its outer circumferential surface with at least one lug capable of locking in a groove formed on the inner circumferential surface of the fixing ring.

According to a second variant, it is the fixing ring which is provided on its inner circumferential surface with at least one lug capable of locking in a groove formed on the outer circumferential surface of the tubing for access to the mixing chamber .

In the configurations in which the tube and the fixing ring cooperate along threads of the multi-start type, the second end 11 of the locking ring has tongues 12 capable of occupying the space between portions 23 formed on the second end 21 of the fixing ring, carrying the threads 22.

Advantageously, the portions 23 are of increasing height, so that the tongues 12 follow the increasing top of these portions like a ramp during the screwing operation and push back the locking ring, until said tongues fall into the space between the portions 23 under the action of the return force of the spring, once the end of the screwing has been reached.

In order to simplify the manufacture of the pump, the constituent elements are preferably manufactured by injection of thermoplastic plastic materials chosen from the list defined by polyamides, polyvinylidene fluorides, high density polyethylenes, loaded or unfilled polypro-pylenes, polyformaldehydes.

In order to seal the metering mechanism completely, sealing means 6 are interposed between the outer circumferential surface of the nozzle 75 and the circumferential surface inside the tube 43 for access to the mixing chamber.

Now concerning the method of mounting a proportional metering pump in accordance with one of the embodiments described above, the screwing of the fixing ring 2 is first of all started with the tubing for access to the cavity inside the hydraulic machine. At the end of the screwing, the second end 11 of the locking ring is made to rotate with the second end 21 of the fixing ring by complementary shape. As explained above, any type of complementarity can be used such as the tongues 12 complementary to the spaces between the threads 22. These complementarities are carried for one by the locking ring and for the other by the fixing ring. The action of the return force of the spring subjected to compression during the screwing, allows one of the complementary forms to overcome the obstacle during the screwing and to be inserted in the corresponding complementary form at the end of the screwing. At the end of the screwing, the unscrewing of the fixing ring is made impossible.

Now concerning the method for dismantling a proportional metering pump in accordance with one of the embodiments described above, the locking ring is made to translate so as to move the first end of said ring away from the shoulder 430 against which it was in support. In this way, the complementary forms are disengaged. Then, the unscrewing ring is unscrewed from the access pipe 43.

Of course, the invention is not limited to the examples which have just been described and numerous modifications can be made to these examples without departing from the scope of the invention. In addition, the different characteristics, forms, variants and embodiments of the invention can be associated with each other in various combinations as long as they are not incompatible or mutually exclusive of each other.

Claims (14)

1. A proportional metering pump comprising a hydraulic machine (4) provided with an inlet (40) and an outlet (41), a metering mechanism (7) provided with a suction adjustment (75) provided with a suction check valve (80) and communicating at one of its ends with an access nozzle to a cavity internal to the pump and, at the other of its ends, with a tank of product to be metered, the hydraulic machine extending along a longitudinal axis (9) and enclosing a member designed to perform a reciprocating movement, the supplying of the pump with liquid at the inlet triggering the reciprocating movement of the member, said movement alternately provoking a suction through the adjustment into the internal cavity with opening of the suction check valve (80) when the member moves away from the adjustment (75) then an expulsion at the outlet (41) of the pump with closure of the suction check valve when the member approaches the adjustment,
   Said the pump further comprising means for fixing the adjustment (75) to the access nozzle to the cavity internal to the hydraulic machine (43), said means comprising:

   - a fixing ring (2) provided with a first end (20) and a second end (21) and mounted to rotate about one of the ends of the adjustment (75),

   characterized in that means for fixing the adjustment (75) comprise further:

   - a blocking ring (1) provided with a first end (10) and a second end (11), and mounted to translate along the longitudinal axis (9) along the access nozzle to the mixing chamber (43), the first end (10) of said ring being pressed toward the metering mechanism against a shoulder (430) formed on said access nozzle by means of a spring (3),

   the fixing ring and the access nozzle to the cavity internal to the hydraulic machine being capable of cooperating by screwing, at the end of which the second end (11) of the blocking ring is secured with the second end (21) of the fixing ring by complementarity of form, so as to lock the unscrewing of the fixing ring.
2. The proportional metering pump as claimed in claim 1, characterized in that the screwing is less than a half-turn.
3. The proportional metering pump as claimed in one of claims 1 and 2, characterized in that the fixing ring comprises, at its second end (21) and at its inner circumferential surface, a multi-start male threading consisting of two to eight threads (22) extending along one and the same helix, while the access nozzle to the cavity internal to the hydraulic machine is provided with a complementary female threading (44).
4. The proportional metering pump as claimed in claim 3, characterized in that the multi-start male threading consists of four threads extending over a length corresponding to a screwing by an eighth of a turn.
5. The proportional metering pump as claimed in claim 1 or 2, characterized in that the access nozzle to the cavity internal to the hydraulic machine comprises a multi-start male threading consisting of two to eight threads extending along one and the same helix, the fixing ring being provided, at its second end (21) and at its inner circumferential surface, with a complementary female threading.
6. The proportional metering pump as claimed in claim 5, characterized in that the multi-start male threading consists of four threads extending over a length corresponding to a screwing by an eighth of a turn.
7. The proportional metering pump as claimed in claim 1 or 2, characterized in that the access nozzle to the cavity internal to the hydraulic machine and the fixing ring cooperate by screwing by a configuration of bayonet type, one of the access nozzle to the internal cavity and the fixing ring being provided with at least one snug capable of being blocked in a groove formed on the other of the access nozzle to the internal cavity and the fixing ring.
8. The proportional metering pump as claimed in either one of claims 3 and 4, characterized in that the second end (11) of the blocking ring comprises tongues (12) capable of occupying the space between portions (23) of increasing height formed on the second end (21) of the fixing ring, the threads being borne by said portions.
9. The proportional metering pump as claimed in any one of the preceding claims, characterized in that the constituent elements of the pump are manufactured by injection of thermoplastic plastic materials chosen from the list defined by polyamides, polyvinylidene fluorides, high density polyethylenes, filled or unfilled polypropylenes, polyformaldehydes.
10. The proportional metering pump as claimed in any one of the preceding claims, characterized in that sealing means (6) are interposed between the adjustment (75) and the access nozzle to the mixing chamber (43).
11. A method for mounting a proportional metering pump conforming to any one of claims 1 to 10, characterized in that the fixing ring with the access nozzle to the cavity internal to the hydraulic machine is screwed until the second end of the blocking ring is secured in rotation with the second end of the fixing ring by complementarity of form, so as to lock the unscrewing of the fixing ring.
12. The method for mounting a proportional metering pump as claimed in the preceding claim, characterized in that the screwing is less than a half-turn.
13. A method for dismantling a proportional metering pump conforming to any one of claims 1 to 10, characterized in that the blocking ring is translated so as to separate the first end of said ring from the shoulder against which it was bearing, then the fixing ring is unscrewed from the access nozzle to the cavity internal to the hydraulic machine.
14. A method for dismantling a proportional metering pump as claimed in the preceding claim, characterized in that the unscrewing is less than a half-turn.

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