WO2011073924A1

WO2011073924A1 - Multi-material electrovalve

Info

Publication number: WO2011073924A1
Application number: PCT/IB2010/055839
Authority: WO
Inventors: Claudio Bottinelli
Original assignee: Ceme S.P.A.
Priority date: 2009-12-16
Filing date: 2010-12-15
Publication date: 2011-06-23
Also published as: EP2513531A1; ITMI20092204A1

Abstract

An electrovalve comprises a main body (2) made of plastic material for food and defining a duct (3) for passage of a fluid; and an electromagnetic actuator (6), associated with said main body (2) and having a closure member (7) that is movable between a first operating condition at which it is at least partly housed in said main body (2) to occlude the duct (3) and stop passage of fluid, and a second operating condition at which it is not housed in the main body (2) so as to enable passage of fluid through said duct (3).

Description

"MULTI-MATERIAL ELECTROVALVE"

Description

The present invention relates to an electrovalve, application of which occurs in apparatuses where supply of water vapour or an alimentary liquid product of various kind is required. In particular, the present invention advantageously applies to automatic machines for production and supply of coffee, tea or other drinks of various kind. Also used are electrovalves for producing aqueous vapour, generally intended for preparation of "cappuccino" or the like.

It is known that electrovalves comprise a main body generally made of metal, brass for example, defining a duct through which a fluid is caused to flow into the electrovalve. The main body has an inlet duct connected to a distribution pipe of a respective fluid product, and an outlet duct connected to a member for fluid flowing. Also known are many-way electrovalves, provided with a series of inlet ducts, each of which is connected to a distribution pipe of a respective fluid product. In this manner, within the single electrovalve different alimentary liquid products can be distributed .

Disposed within the main body is a closure member that, operated by a control device, regulates passage of the fluid from the inlet duct to the outlet duct. This control device comprises a cylindrical slider (or core) coaxially and rigidly connected to the closure member and an electromagnetic coil. In detail, the closure member is driven by the slider so as to open or close passage between the inlet and outlet ducts. The electrovalves of known type are normally closed and are opened when a user base needs some fluid. However there are electrovalves operating according to the opposite principle. In this case, the electrovalves are normally open and are closed in case of need. Disposed around the rod is an electromagnetic coil for movement of the slider. In detail, when the electrovalve has to be opened, the coil is powered and generates an electromagnetic field acting on the slider. Since the slider is made of a ferromagnetic material, the slider rises and drags along the closure member that makes the passage between the inlet duct and outlet duct clear.

When flowing has to be interrupted, powering of the coil is stopped and a return spring moves the slider downwards. Thus the closure member will prevent passage of the fluid again.

However, the electrovalves of known type have some drawbacks mainly connected with the material of which the main body is made.

It is in fact to be considered that the regulations in force as regards food do not allow use of some particular materials that even in small amounts can damage the drink integrity and injure the user's health.

In this context, the metal of which the main body is made appears to be inappropriate based on the above mentioned regulations. In fact, as above described, the main body is generally made of brass or treated brass and therefore contains amounts of lead or nicked that are not in compliance with the regulations on food. Another drawback is given by the particularly expensive and heavy structure of the electrovalve . This drawback too is due to the metal material of which the main body is made that, unlike the ferromagnetic core, must not be necessarily made of metal.

Accordingly, it is an aim of the present invention to provide an electrovalve solving the above mentioned drawbacks .

In particular, the present invention aims at providing a versatile electrovalve that is in compliance with the regulations on food in force all over the world. In particular, it is an aim of the present invention to make available an electrovalve in which the parts in contact with the fluid product are made of a material that is non-toxic and is able to protect and ensure the integrity of the food. In addition, another aim of the present invention is to propose a lightweight electrovalve that is of simple structure and reduced costs.

Further features and advantages will become more apparent from the detailed description of a preferred but not exclusive embodiment of an electrovalve in accordance with the present invention. This description will be set out hereinafter with reference to the accompanying drawings, given by way of non-limiting example, in which:

- Fig. 1 is a perspective view of an electrovalve according to the present invention;

- Fig. 2 is a sectional view of the valve seen in Fig. 1 ; and

- Fig. 3 is a perspective and section view of a variant of the electrovalve according to the present invention (it is in particular a so-called "three-way" electrovalve) . Referring specifically to the accompanying drawings, an electrovalve according to the present invention has been generally identified by reference numeral 1.

In particular, the electrovalve 1 is mainly used in automatic machines for producing drinks. For instance, the electrovalve 1 is used for controlling supply to the outside of hot drinks such as coffee or tea, generally distributed to a pressure of 10-15 bars. The electrovalve 1 can be also employed for control of the steam used in particular for emulsifying milk in preparing "cappuccino". In this case the electrovalve controls the steam emission to a pressure varying from 3 to 3.5 bars.

However, the present electrovalve can also be used in any automatic machine in which distribution of one or more fluids under pressure is to be controlled. In particular, the electrovalve 1 has an internally hollow main body 2 defining a duct 3 for passage of a fluid. In greater detail, the passage duct 3 has at least one inlet channel 4 and one outlet channel 5 in fluid communication with each other so as to enable passage of the fluid.

In the embodiment shown by way of example and therefore not in a limiting sense, a duct 2 is shown which has a substantially tubular conformation and circular cross- section and extends along a respective longitudinal axis. However, the shape and course of the fluid defined by the inlet 4 and outlet 5 channels can be of any nature depending on the different application requirements of the electrovalve 1.

Yet, in a simplified embodiment, duct 3 has a single inlet channel 4 adapted to be coupled to a fluid- production source not shown as of known type and not being part of the present invention.

However, duct 3 can be also provided with a series of inlet channels 4 to enable passage of a plurality of alimentary fluids different from each other. In this case, each inlet channel 4 is suitably connected to a respective duct dedicated to a particular drink.

Advantageously, the main body 2 is made of plastic material for food. In particular, any plastic material suitable for food can be used for the main body 2, which material must be able not to absorb moisture and to be temperature-stable until 180°C.

Preferably, the body 2 is fully made of a polymeric material and more particularly of plastic material for food (that preferably must not be hygroscopic) . More generally, this polymeric material may belong to the family of the so-called polyphthalamides or PPAs.

The electrovalve 1 further comprises an electromagnetic actuator 6 associated with the main body 2 and having a closure element 7 adapted to occlude/enable passage of the fluid inside duct 3.

In particular, the electromagnetic actuator 6 has a tube 8 made of steel and associated with the main body 2 between said inlet channel 4 and outlet channel 5. Tube 8 has a substantially tubular conformation and is internally hollow to enable axial sliding of the closure member 7.

As clearly shown in Fig. 1, the body 2 has an opening 3a with which tube 8 is associated so as to bring the tube's cavity into communication with duct 3. In this manner, the closure element 7 can be movable inside tube 8 between a first operating condition at which it is at least partly housed in the main body 2 so as to occlude duct 3 and stop passage of fluid, and a second operating condition at which it is not housed in the main body 2 so as to enable passage of the fluid in duct 3.

The closure element 7 is preferably made of ferromagnetic material so that it is moved by the electromagnetic action generated by a coil 9. Coil 9, of known type and therefore not described and only diagrammatically illustrated, preferably extends around tube 8 to enable it to directly act on the closure element 7. It is also to be pointed out that tube 8 has a flange 10 placed at a lower end of said tube 8 and in engagement with a cylindrical outer surface of the main body 2. Flange 10 is fastened to the main body 2 by at least one locking screw 11 insertable into respective openings 12 formed in the flange 10 and the cylindrical outer surface of body 2.

Preferably two screws 11 are present and they are housed on opposite sides of tube 8 to steadily anchor the main body 2 to the electrovalve core consisting of coil 9, and to tube 8 provided with the respective flange 10.

Advantageously, tube 8, flange 10 and the respective screws 11 are made of metal material. In this manner, only the electrovalve portion that comes into contact with the fluid product is made of plastic material.

Use of plastic material for making the main body 2 has important advantages. First, the plastic material can be worked more easily and has lower cost and weight as compared with metal materials. Consequently, the whole electrovalve is lighter, cheaper and has reduced manufacturing costs.

In addition, duct 3 fully made of plastic material is more hygienic and can ensure the quality of the distributed product maintaining the organoleptic integrity of same.

It is also to be pointed out that plastics do not contain any material dangerous for the user's health, such as some components present in brass. Consequently, the electrovalve 1 is also in compliance with the strictest food regulations in force in the different countries .

Finally, a further advantage of the present invention resides in that the main body 2 of plastic material keeps the temperature of the fluid passing through duct 3 stable. In fact, the heat loss in the plastic material is lower and therefore more stable than that of the metal material, such as brass used in known electrovalves .

Claims

C L A I M S

1. An electrovalve, comprising:

- an internally hollow main body (2) defining a duct (3) for passage of a fluid;

- an electromagnetic actuator (6), associated with said main body (2) and having a closure member (7) that is movable between a first operating condition at which it is at least partly housed in said main body (2) to occlude the duct (3) and stop passage of fluid, and a second operating condition at which it is not housed in the main body (2) so as to enable passage of fluid through said duct (3),

characterised in that said main body (2) is made of plastic material for food.

2. An electrovalve as claimed in the preceding claim, characterised in that said main body (2) is made of a polymeric material for food, preferably a non- hygroscopic material and more preferably a polymeric material belonging to the polyphthalamide family.

3. An electrovalve as claimed in anyone of the preceding claims, characterised in that said main body (2) has a substantially tubular conformation defining at least one inlet channel (4) and an outlet channel (5) in fluid communication with each other to enable passage of said fluid.

4. An electrovalve as claimed in the preceding claim, characterised in that said main body (2) has a series of inlet channels (4) adapted to enable passage of a plurality of fluids in the form of food different from each other and each of which flows in a respective inlet channel (4).

5. An electrovalve as claimed in claim 4 or 5, characterised in that said closure member (7) in the first operating condition is disposed between said inlet channel (4) and said outlet channel (5); said closure member (7) being made of a ferromagnetic material.

6. An electrovalve as claimed in anyone of the preceding claims, characterised in that said electromagnetic actuator (6) comprises a tube (8) made of steel and associated with the main body (2), said tube (8) being fully hollow to enable sliding of said closure member (7) between the respective first and second operating conditions.

7. An electrovalve as claimed in the preceding claim, characterised in that said tube (8) is disposed in the region of an electric coil (9) so as to distribute a magnetic field to said closure member (7); said tube (8) having a flange (10) in engagement with an outer cylindrical surface of said main body (2).

8. An electrovalve as claimed in the preceding claim, characterised in that it further comprises at least one locking screw (11) insertable into respective openings (12) formed in the flange (10) and in the outer cylindrical surface, to as to anchor the tube (8) to said main body (2) .