Direct current electric actuator, for domestic appliances in particular

Abstract

 The electrically controlled actuator (10), in domestic appliances in particular, comprises
- a shell (12) realized in a single piece in 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);
- 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 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).

Description

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

[0002] More specifically, the invention refers to an electrically controlled direct current actuator intended, preferably but not necessarily, for use in distributor devices in general used in domestic appliances such as washing machines, dishwashers and the like.

[0003] 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.

[0004] This and other purposes are realized according to the invention by means of an electrically controlled direct current actuator, in particular for distributor devices suitable for use in domestic appliances such as washing machines, dishwashers and the like, comprising

• a shell realized in a single piece in ferromagnetic material, substantially shaped in C form and including a first and a second lateral branch reciprocally opposed and interconnected by an intermediate portion;
• a coil of conductor wire fixed to the shell in such a way that its axis extends in a direction substantially at right angles to the above-mentioned lateral branches of the shell; and
• a ferromagnetic nucleus mounted movably with respect to the shell in a manner axially translatable inside the coil and suitable for passing from an axial rest position to an axial working position as an effect of excitation of the coil.

[0005] 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.

[0006] With reference to figures 1 and 2, an electrically controlled direct current actuator according to the invention is indicated as a whole as 10.

[0007] 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.

[0008] 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 the pre-existing technology, this shell was generally made in two components intended to be welded together.

[0009] 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.

[0010] 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.

[0011] 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.

[0012] As can be seen in figure 2, the first lateral branch 14 of the shell 12, advantageously but not necessarily, 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. In a manner obvious to a technician in the sector, the formation 30 and the end 32 may also have different complementary forms, for example conical (variants not shown).

[0013] 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. Indifferently, in other embodiment variants, this function can instead be carried out by the other end of the nucleus 28.

[0014] The complementary conical or 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.

[0015] Conveniently, the formation 30 is turned towards the region outside the shell 12, and the shaped end 32 of the nucleus 28 comprises a conical or 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.

[0016] Nevertheless, in an embodiment variant not illustrated, the formation 30 can also be turned towards the region inside the shell 12 and, as a consequence, the end 32 of the nucleus 28 is then shaped in such a way as to have a corresponding conical or truncated cone recess.

[0017] 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.

[0018] 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.

[0019] Naturally, without prejudice to the principle of the invention, the forms of actuation and the embodiment details can be widely varied compared with what has been described and illustrated for non-limiting exemplificative purposes only, without thereby leaving the framework of the invention as defined in the annexed claims.

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);

- 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).

2. Electrically controlled actuator (10) according to Claim 1, in which the first or second lateral branch (14; 16) of the shell (12) has a formation (30) with a substantially conical or truncated cone form; and
the nucleus (28) has a corresponding end (32) shaped in a manner substantially complementary to said formation (30).

3. Electrically controlled actuator according to Claim 2, in which said formation (30) is turned towards the region outside the shell (12) and the shaped end (32) of the nucleus (28) comprises a conical or truncated cone protrusion.

4. Electrically controlled actuator according to Claim 2, in which said formation (30) is turned towards the region inside the shell (12) and the shaped end (32) of the nucleus (28) comprises a conical or truncated cone recess.

5. Electrically controlled actuator according to any one of the preceding claims, in which the nucleus (28) is substantially hollow.

6. Electrically controlled actuator according to Claim 5, in which the nucleus (28) is manufactured by drawing.

7. Electrically controlled actuator according to any one of Claims 2 to 6, in which the formation (30) is made by drawing or coining, and shearing.

8. 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).

9. Electrically controlled actuator according to Claim 8, in which the collar (36) protrudes towards the region outside the shell (12).

10. Electrically controlled actuator according to Claim 8, in which the collar (36) protrudes towards the region inside the shell (12).

11. Actuator according to Claim 8 and any one of Claims 2 to 10, 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).

12. Distributor device for a washing and/or rinsing agent in a washing machine or dishwasher comprising an electrically controlled actuator (10) according to any one of the preceding claims.

Drawing