Direct current electric actuator, for domestic appliances in particular

Description

[0001] The present invention refers to an electrically controlled actuator.

[0002] More specifically, the invention refers to an electrically controlled direct current actuator of the kind defined in the preamble of claim 1.

[0003] US 2003/155839 A1 discloses an actuator of that kind with a cylindrical tubular nucleus having a flat annular terminal surface for abutment against a corresponding flat annular surface of a ferromagnetic frame or shell.

[0004] EP-A-0 185 262 discloses an actuator wherein a blind conical internal protrusion of a ferromagnetic frame or shell is adapted to engage a corresponding frusto-conical end recess of the nucleus.

[0005] One purpose of the present invention is to realize an electrically controlled actuator as specified above, of a perfected type and which is reliable and can be produced in a simple and economical manner.

[0006] This and other purposes are realized according to the invention by means of an electrically controlled direct current actuator having the features defined in claim 1.

[0007] Further characteristics and advantages of the invention will appear clear from the detailed description which follows, given for purely exemplificative and not limiting purposes, with reference to the attached drawings, in which:

figure 1 is a perspective view of a preferred form of embodiment of the actuator according to the invention; and

figure 2 is a longitudinal section view of the actuator along the line II-II of figure 1.

[0008] With reference to figures 1 and 2, an electrically controlled direct current actuator according to the invention is indicated as a whole as 10.

[0009] The actuator 10 is suitable for insertion in devices for distributing a washing and/or rinsing agent for domestic appliances such as washing machines, dishwashers and the like (not illustrated), but can also be used in other applications, without leaving the framework of the invention by so doing.

[0010] The actuator 10 comprises a shell 12 made in a single piece with a sheet of ferromagnetic material, substantially shaped in C form, and including a first and second lateral branch 14, 16 reciprocally opposed and interconnected by an intermediate portion 18. The monolithic conformation of the shell 12 makes it possible to simplify the assembly of the actuator 10 as, according to a pre-existing technology, this shell was generally made in two components intended to be welded together.

[0011] As can be seen in figure 2, the shell 12 houses, in a fixed manner in its internal region, a reel 20 around which a coil 22 of electrically insulated conductor wire is wound, and with, at its ends, a pair of connection elements 24, such as lamellar pins. Preferably the reel 20 and the coil 22 are enclosed by an insulating casing 26 with a substantially cylindrical form, from which the connection elements 24 protrude towards the outside.

[0012] The coil 22 has an axis A-A which extends in a direction substantially at right angles to the first and second branch 14, 16 of the shell 12.

[0013] The actuator 10 also comprises a ferromagnetic nucleus 28 mounted movably with respect to the shell 12, in a manner axially translatable inside the coil 22. The nucleus 28 is suitable for passing, in a manner in itself known, from an axial rest position (not shown) to an axial working position (shown in the figures) as an effect of excitation of the coil 22. Optionally, the nucleus 28 can be connected to elastic elements (not illustrated) of types per se known, for example a traction or compression spring, intended to hold it in/return it to the rest position when the coil 22 is deenergized.

[0014] As can be seen in figure 2, the first lateral branch 14 of the shell 12 has a formation 30 with a substantially truncated cone form and the nucleus 28 has a corresponding end 32, shaped in a manner substantially complementary to the formation 30.

[0015] In this form of embodiment, the end 32 is intended in a manner in itself known to cooperate, in a manner in itself known, with kinematic or lever mechanisms (not illustrated) by means of the translation of the nucleus 28.

[0016] The complementary truncated cone configuration between the end 32 of the nucleus 28 and the formation 30 of the shell 12 advantageously makes it possible to create an air gap (between the nucleus 28 and the formation 30) with a width which is lower than the stroke of the nucleus 28 relative to said formation. This makes it possible to obtain a dampening of the translation movement of the nucleus 28, due to the progressive variation of the air gap between the nucleus 28 and the formation 30. Furthermore, the above configuration permits improved centring of the nucleus 28 with respect to the shell 12 and to the casing 26, in such a way as to prevent its displacement from the A-A axis of the coil 22.

[0017] Conveniently, the formation 30 is turned towards the region outside the shell 12, and the shaped end 32 of the nucleus 28 comprises a truncated cone protrusion. This configuration is found to be advantageous as it facilitates the assembly of the components of the actuator 10 as a whole. In this way, it is not necessary to open out the lateral branches 14, 16 to permit the insertion of the reel-coil-casing 20-22-26 assembly into the region inside the shell 12.

[0018] Preferably, the nucleus 28 is hollow and manufactured by means of drawing, and the formation 30 is manufactured by means of a drawing or coining operation, and a shearing operation.

[0019] The second lateral branch 16, opposite the first lateral branch 14 comprising the formation 30, advantageously has an opening 34 through which the nucleus 28 faces towards the outside of the shell 12. Around the opening 34, the second lateral branch 16 conveniently comprises a collar 36 integral with it and protruding towards the region outside the shell 12. Indifferently the collar 36 can be protruding towards the region inside the shell 12. The presence of the collar 36 favours the efficiency of the magnetic flux induced by excitation of the coil 22.

Claims

1. Electrically controlled direct current actuator (10), in particular for distributor devices suitable for use in domestic appliances such as washing machines, dishwashers and the like, comprising

- a shell (12) realized in a single piece in ferromagnetic material, substantially shaped in C form and including a first and a second lateral branch (14, 16) reciprocally opposed and interconnected by an intermediate portion (18); the first or second lateral branch (14; 16) of the shell (12) having a formation (30) with a substantially truncated-cone external form turned towards the region outside the shell (12);

- a coil (22) of conductor wire fixed to the shell (12) in such a way that its axis (A-A) extends in a direction substantially at right angles to the abovementioned lateral branches (14, 16) of the shell (12); and

- a ferromagnetic nucleus (28) mounted movably with respect to the shell (12) in a manner axially translatable inside the coil (22) and suitable for passing from an axial rest position to an axial working position as an effect of excitation of the coil (22);

the actuator (10) being characterised in that said formation (30) of the shell (12) has a substantially truncated-cone internal form, and

the nucleus (28) has a corresponding end (32) comprising a truncated-cone protrusion shaped in a manner substantially complementary to the internal form of said formation (30); said formation (30) of the shell (12) having an opening through which said protrusion (32) of the nucleus (28) is accessible from outside said shell (12).

2. Electrically controlled actuator according to claim 1, in which the nucleus (28) is substantially hollow.

3. Electrically controlled actuator according to Claim 2, in which the nucleus (28) is manufactured by drawing.

4. Electrically controlled actuator according to any one of Claims 1 to 3, in which the formation (30) is made by drawing or coining, and shearing.

5. Electrically controlled actuator according to Claim 1, in which the second or first lateral branch (16; 14) has an opening (34) through which the nucleus (28) faces towards the outside of the shell (12); said second or first lateral branch (16; 14) comprises a collar (36) integral with it, located around the opening (34).

6. Electrically controlled actuator according to Claim 5, in which the collar (36) protrudes towards the region outside the shell (12).

7. Electrically controlled actuator according to Claim 5, in which the collar (36) protrudes towards the region inside the shell (12).

8. Actuator according to Claim 5, in which the second or first branch (16; 14) provided with the collar (36) is opposite the first or second lateral branch (14; 16) provided with the formation (30).

Ansprüche

1. Elektrisch gesteuertes Gleichstrom-Stellglied (10), insbesondere für Verteilereinrichtungen, welche zur Verwendung in Haushaltsgeräten, wie etwa Waschmaschinen, Geschirrspülern und dergleichen geeignet sind, umfassend

- ein einstückiges Gehäuse (12) aus ferromagnetischem Material, welches im Wesentlichen C-förmig ausgebildet ist und erste und zweite Seitenabschnitte (14; 16) aufweist, die einander gegenüber liegend und durch einen Mittelabschnitt (18) verbunden sind, der erste und der zweite Seitenabschnitt (14; 16) des Gehäuses (12) besitzen eine Ausformung (30) mit einer im Wesentlichen kegelstumpfförmigen äußeren Form, die gegen einen Bereich außerhalb des Gehäuses (12) gerichtet ist;

- eine am Gehäuse (12) derart befestigte Leiterdrahtspule (22), dass sich deren Achse (A-A) in einem im Wesentlichen rechten Winkel zu den oben erwähnten Seitenabschnitten (14; 16) des Gehäuses (12) erstreckt und

- einen ferromagnetischen Kern (28), welcher im Bezug zum Gehäuse (12) derart beweglich angeordnet ist, dass er in der Spule (22) axial verschiebbar ist und geeignet ist, von einer axialen Ruhestellung in eine axiale Betriebsstellung als Folge der Erregung der Spule (22) verschoben zu werden;
das Stellglied (10) ist dadurch gekennzeichnet, dass die Ausformung (30) des Gehäuses (12) eine im Wesentlichen kegelstumpfförmige Form aufweist und
der Kern (28) ein entsprechendes Ende (32) mit einem kegelstumpfförmigen Vorsprung aufweist, welcher im Wesentlichen komplementär zur inneren Form der Ausformung (30) ist, wobei die Ausformung (30) des Gehäuses (12) eine Öffnung aufweist, durch welche der Vorsprung (32) des Kerns (28) von außerhalb des Gehäuses (12) zugänglich ist.

2. Elektrisch gesteuertes Stellglied nach Anspruch 1, bei dem der Kern (28) im Wesentlichen hohl ausgeführt ist.

3. Elektrisch gesteuertes Stellglied nach Anspruch 2, bei dem der Kern (28) durch Ziehen hergestellt ist.

4. Elektrisch gesteuertes Stellglied nach jedem einzelnen der Ansprüche 1 bis 3, bei welchem die Ausformung (30) durch Ziehen oder Prägen, und Scheren hergestellt ist.

5. Elektrisch gesteuertes Stellglied nach Anspruch 1, bei dem der zweite oder erste Seitenabschnitt (16; 14) eine Öffnung aufweist, durch welche der Kern (28) gegen die Außenseite des Gehäuses (12) gerichtet ist; der zweite oder erste Seitenabschnitt (16; 14) besitzt einen mit diesen integrierten Kragen (36), welcher um die Öffnung (34) angeordnet ist.

6. Elektrisch gesteuertes Stellglied nach Anspruch 5, bei welchem der Kragen (36) gegen einen Bereich außerhalb des Gehäuses (12) vorspringt.

7. Elektrisch gesteuertes Stellglied nach Anspruch 5, bei welchem der Kragen (36) gegen einen Bereich innerhalb des Gehäuses (12) vorspringt.

8. Elektrisch gesteuertes Stellglied nach Anspruch 5, bei welchem der zweite oder erste mit einem Kragen (36) versehene Seitenabschnitt (16; 14) gegenüber dem ersten oder zweiten mit der Ausformung (30) versehenen Seitenabschnitt (14; 16) angeordnet ist.

Revendications

1. Actionneur à commande électrique et à courant continu (10), en particulier pour des dispositifs distributeurs appropriés pour une utilisation dans des appareils domestiques comme les lave-linge, les lave-vaisselle et appareils similaires, comprenant :

- une coque (12) formée d'une seule pièce en matériau ferromagnétique, ayant sensiblement la forme d'un C et comprenant une première et une deuxième branche latérale (14, 16) mutuellement opposées et interconnectées par une partie intermédiaire (18), la première ou deuxième branche latérale (14 ; 16) de la coque (12) comportant une formation (30) présentant une forme extérieure sensiblement tronconique, tournée vers la région située à l'extérieur de la coque (12) ;

- une bobine (22) en fil conducteur fixée à la coque (12) de telle manière que son axe (A-A) s'étend dans une direction substantiellement à angle droit par rapport aux branches latérales susmentionnées (14, 16) de la coque (12) ; et

- un noyau ferromagnétique (28) monté de façon mobile par rapport à la coque (12) de telle manière qu'il peut translater axialement à l'intérieur de la bobine (22) et adapté pour passer d'une position de repos axial à une position de travail axial en conséquence de l'excitation de la bobine (22) ;

l'actionneur (10) étant caractérisé en ce que ladite formation (30) de la coque (12) a une forme intérieure sensiblement tronconique, et

le noyau (28) a une extrémité correspondante (32) comprenant une protubérance tronconique présentant une forme substantiellement complémentaire à la forme intérieure de ladite formation (30), ladite formation (30) de la coque (12) comportant une ouverture par laquelle ladite protubérance (32) du noyau (28) est accessible depuis l'extérieur de ladite coque (12).

2. Actionneur à commande électrique selon la revendication 1, dans lequel le noyau (28) est substantiellement creux.

3. Actionneur à commande électrique selon la revendication 2, dans lequel le noyau (28) est fabriqué par étirage.

4. Actionneur à commande électrique selon l'une quelconque des revendications 1 à 3, dans lequel la formation (30) est réalisée par étirage ou par matriçage, suivi d'un cisaillement.

5. Actionneur à commande électrique selon la revendication 1, dans lequel la deuxième ou la première branche latérale (16 ; 14) comporte une ouverture (34) à travers laquelle le noyau (28) fait face à l'extérieur de la coque (12), ladite deuxième ou première branche latérale (16 ; 14) comprenant un collier (36) intégré à celle-ci, situé autour de l'ouverture (34).

6. Actionneur à commande électrique selon la revendication 5, dans lequel le collier (36) fait saillie vers la région située à l'extérieur de la coque (12).

7. Actionneur à commande électrique selon la revendication 5, dans lequel le collier (36) fait saillie vers la région située à l'intérieur de la coque (12).

8. Actionneur selon la revendication 5, dans lequel la deuxième ou la première branche (16 ; 14) pourvue du collier (36) est opposée à la première ou deuxième branche latérale (14 ; 16) pourvue de la formation (30).

Drawing