FR2520470A1 - THERMOELECTRIC VALVE WITH ONE OR MORE WAYS, IN PARTICULAR FOR WASHING MACHINES AND / OR REFRIGERATED MACHINES - Google Patents

Abstract

ONE OR MORE WAY THERMO-ELECTRIC VALVE, ESPECIALLY FOR WASHING MACHINES ANDOR FOR REFRIGERANT UNITS, INCLUDING A HOLLOW BODY WITH AN INLET CONNECTION AND ONE OR MORE OUTLET CONNECTIONS FOR FLUIDS, LIQUIDS OR GAS; LEDIT HOLLOW BODY CONTAINING A VALVE MAINTAINED CLOSED BY TARTED ELASTIC MEANS AND OPENED BY THE PRESSURE GENERATED BY THE INCREASE IN VOLUME OF A MASS OF WAX HEATED BY A THERMISTOR (C.T.P.) SUPPLIED WITH ELECTRIC CURRENT.

Description

25204?

  One or more way thermoelectric valve, especially for washing machines and / or refrigerating machines

  It is known that in washing machines water that is intro-

  pick in the tank must pass through a solenoid valve controlled by an electro-

  magnet, which, when excited, discovers one or more capillary orifices which generate a set of pressures intended to cause the opening of the valve However, this known type of solenoid valve can give rise to certain drawbacks, among which :: occlusion of the capillary orifices, caused by calcareous deposits or by other foreign bodies; blocking of the movable core of the valve in the closed position or, what is worse, in the open position cutting the winding of the electromagnet short circuit between the turns of the winding with overheating is of the latter and risk of melting of the plastic parts

  water hammer when closing the valve, difficult to control

  lable, with risk of rupture of the supply piping difficulty in supplying the machine tank with the quantity of water required in the event of a pressure drop in the supply network excessive noise from the solenoid valve, intended to increase over time; excessive dimensions, especially for groups of valves with multiple outlets risk of flooding when the valve is blocked in the open position. It is also known that in refrigerators with a single refrigeration cell, that is to say in the majority of cases, only one refrigeration unit is provided which essentially comprises a compressor, an external radiator , a condenser inside the cell and: a series of tubular conduits, filters and thermostat

regulation.

  Current requirements, however, require that refrigerators

  teurs have a compartment at moderate temperature, that is to say slightly higher than OO Celsius, for the conservation of vegetables, wines and other food products These requirements posed the manufacturers the problem of how to realize this possibility with the minimum cost price, that is to say without adding a second refrigeration unit or compressor. Consequently, the current trend in household refrigerators with two compartments is that which consists in partially exploiting the cold in the compartment which feels the least the demand for it, i.e.

  in what is commonly called the "vegetable bin".

  Although it is fairly widely accepted, this solution has the drawback of not being able to be thermally controlled, namely

  that if the temperature can on the one hand be very well controlled in the

  part cold or in the freezer, it is quite different in

regarding the vegetable drawer.

  As you can imagine, the ideal solution would be to mount two separate and independent refrigeration units, but it goes without saying

  that it would involve high cost prices.

  A frequently used alternative solution is that of mounting a valve which intercepts the fluid / gas by conveying it to a

  compartment or the other as required.

  These valves are electromagnetically actuated and can therefore

  can be controlled by a common thermostat Naturally, everything is

  connected to a single compressor, possibly oversized.

  Although the solenoid valve turns out to be rather expensive, this solution

  allows significant savings compared to the use of two compres-

  at the same time offers the possibility of perfectly adjusting the time

  temperature in the two compartments.

  The main purpose of the present invention is to eliminate all the characteristic drawbacks presented by certain known solenoid valves. Another object of the invention is to provide a valve capable of

  ensure reliable operation over time, a very simple structure

  ple, with an advantageous cost price and suitable for use on machines

nes to wash.

  Another object of the invention is to provide a thermoelectric control valve capable of intercepting fluids at a very high pressure, and therefore capable of being used reliably.

on refrigeration machines -

  These objects are achieved by the thermoelectric control valve according to the invention, in particular for washing machines and / or refrigerators, characterized in that it comprises a housing containing a valve body pushed

  in the closed position by the pressure of calibrated elastic means and com-

  mandated to open by the pressure generated in a chamber and then transmitted to the valve as a result of the increase in volume of a mass of

  wax heated by a thermistor (CTP).

  The characteristics of the valve according to the invention will emerge more clearly.

  deny reading the description which follows, given here under

  example with reference to the appended drawings, in which:

  Figure i is a longitudinal sectional view of an embodiment

  preferred tion of the valve according to the invention, in the open and closed position; Figure 2, similar to the previous figure, shows a variant of some elements of the valve

  Figure 3 is a partial view of the valve according to another va-

  laughing Figures 4 and 5 are sectional views of another structural variant of the valve, concerning the location of the thermistor and the valve body; FIG. 6 shows a variant concerning the arrangement of the thermistor;

  Figures 7 and 8 are other schematic views of other variations.

  your structural of the valve according to the invention.

  In accordance with Figure 1, the plane passing through the x-x axis of the valve

  distinguishes, on the high side, half of the valve in the open position

  and, on the bottom side, the other half of this same valve in the closed position.

  The structure of the valve according to the invention comprises a valve body 1

  with a threaded connection 2 which allows the water to flow in the direction indicated

  1 qué par les arrows -y- The reference 3 designates the fitting for fixing

  valve to the washing machine, while reference 4 designates a wire-

  be for incoming water The reference 5 designates on the other hand a valve provided with an elastic seal 6 and whose rod 5 a is slidably mounted in the

  longitudinal direction inside the seat id A spring 7 maintains the support

  pope in the closed position, as shown in the lower part of Figure 1 The end of the rod 5a rests against a seal 8 mounted sliding, but sealed, inside the tubular seat ld which leads into the chamber 9 bounded by the cap 10 The chamber 10 is filled with a

  suitable wax or any other mixture of suitable materials having a coeffi-

  cient characteristic of expansion corresponding to a temperature value prefixed at the level of which this mass undergoes a considerable increase

  in volume, so that in chamber 9 there is a rapid increase

  of and sensitive to the pressure which, by acting on the seal 8, forces it to take the position indicated with 8 a, causing the sliding of the rod 5 a in the opposite direction to that indicated by the arrows - y-, and consequently the opening of the valve 5 against the reaction

  of the spring 7, as shown in the upper part of Figure i.

  In the mass of wax contained in the chamber 9 are drowned one or

  several thermistors 11 connected to electrical terminals 11a which work

  pour tightly the cap 10, which cap is integral-

  ment assembled to the valve body l.

  Said terminals 11a are connected to the electrical supply circuit

  machine through its programming device.

  The operation of the valve is as follows: when the terminals

  They are supplied with electrical energy, the PTC thermistor (or most

  PTC thermistors) it heats up immediately and stabilizes

  at its characteristic temperature.

  Since this temperature is much higher than the melting temperature of the wax, the latter melts in a very short time by increasing in volume, which determines an increase in the pressure in the chamber 9 which causes a push of the wax against the joint 8, which in turn

  pushes rod 5 a until it overcomes the reaction of spring 7 so as to pro-

  mention the opening of the valve 5; When, on the other hand, the electric current

  no longer reaches terminals lla, thermistor il and wax cools

  feels, the latter decreases in volume and the reaction of the spring 7 brings

  consequently the valve 5 with its elastic seal 6 slowly in position-

  of abutment against the seat 1a, by obstructing the passage of the fluid hot and folded down as indicated in 17 The thermistor 11 and the electrical terminals 11a are protected by a thin layer of insulating resin 13 The terminals

  nes lla pass on the other hand an electrically insulating seal 18 and

  extend beyond the housing 12 The rod 5a of the valve bears against the elastic seal 14 and has a perimeter groove intended to receive an annular elastic seal 15 in order to ensure perfect water tightness or other fluid, avoiding that it may mix, even in small quantities, with the wax contained in

room 9.

  FIG. 3 illustrates another variant according to which the thermistor or thermistors 11 are situated outside the chamber 9 constituted by a case 12 a The reference 19 designates a protective cage for the or

  thermistors, whose skirt is pierced so as to improve ventilation

  tion and thermal dispersion of thermistors when power

  electric power comes to an end.

  Figures 4 and 5 illustrate a variant of the valve according to the invention.

  tion, made to be more particularly used on refrigeration machines. The valve of Figure 4 comprises a metal body 1 on the end of which is mounted a heating head 22 which is held in place by a nut which is screwed onto the threaded rod 23 In Figure 4, the heating head 22 is shown in cross section and includes

  inside it one or more PTC 11 thermistors of appropriate power

  required, electrically supplied through the terminals lla and arranged in contact with a housing 27 made of an electrically insulating and heat-resistant material, this same housing being in direct contact with

  the hollow extension filled with wax 9.

  The chamber which contains the wax 9 has a single controlled opening

  lée by a seal 8 mounted sliding but watertight inside the lo-

  5a of the valve 5 which, in the position shown, closes the light

  flow passage between the fluid inlet fitting 4 and the outlet fitting 3 Between the end of the rod 5 a which is inserted in the valve 5 and the housing which receives the same end slidingly there is provided a space 25 Furthermore, the spring 7 tends to maintain the

  valve 5 in the closed position against its housing la.

  The supply of electrical current to terminals lla causes the

  heating of the CPT thermistor (s) Il and thereby the fusion of

  the wax 9 which, by increasing in volume, exerts a strong pres-

  sion on the gasket 8, which in turn pushes the rod 5 a which, after recovering the space 25, causes the axial displacement of the valve 5 and thereby the opening of the light the valve being thus opened, the fluid will pass from the inlet fitting 4 to the outlet or filling fitting

  3 until the valve 5 does not return to close the passage light la.

  This occurs as soon as the supply of electric current to the terminals 11a ceases, which causes the cooling of the wax 9 which,

  by retracting, allows the spring 7 to return the valve 5 to the posi-

tion shown in the figure.

  In the variant shown in Figure 5, the valve, while having the same operation, comprises a body 1 with an inlet connection 4 and two outlet fittings 3.3 b or, conversely, two fittings d 'Entrance

  and as much output, or even just one.

  In this variant, the space existing between the end of the rod 5 a and the housing formed in the valve 5 contains a spring 24 having an arrow significantly greater than that of the spring 7 This arrangement makes it possible to eliminate water hammer during of the operation of the valve and makes it possible to absorb the additional thrust exerted on the rod 26, even when the valve is closed Still according to the variant of FIG. 5, it can be seen that in the position shown the valve 5 closes the passage light lc and leaves the light lf open, and that on the other hand, when the terminals II are electrically supplied and the rod 5 axially pushes the valve in the direction of the arrow -z-, the light lf closes at the same time as the light lc opens, so that connection 4 is alternately put in

  communication either with connection 3 or with connection 3 b, or else

  simultaneously with both if the temperature of the wax 9 is maintained at

  a sufficiently low value to generate on the rod 5 only a push

  relatively moderate so as not to fully compress the

sort 7.

  In the de-excitation phase of the PTC thermistor (s) 1 i,

  it is first of all the spring 24 and successively the spring 7 which

  slide so as to cause the axial displacement of the valve 5 up to

turn off the light Ic.

  The axial clearance 25 between the end of the rod 5 a and the housing of the valve 5 has been provided to compensate for the thermal drift, namely that if the valve is used in a relatively hot medium the wax 9 increases in volume and exerts a certain push on the rod 5 a, which however cannot cause the opening of the valve as long as the end of the rod

  has not recovered the play available in its housing provided on the valve.

  Naturally, the spring 24 could just as easily be provided (as in FIG. 5) or be absent (as in FIG. 4) and, in the first

  In this case, its pitch may be either lower or higher than that of the res-

  sort 7, depending on the effects that one wishes to obtain during operation

valve.

  Furthermore, the spring 7 (FIGS. 4 and 5), intended to cause the closing of the valve when the pushing on the rod 5 a comes to stop, could have any other shape and structure compared to those

  which are shown and can also be mounted in a different way

rent when it is implemented.

  In the variant shown in Figure 6, the PTC thermistor 11 is disposed outside of the housing 30 containing the wax 9 or other heat expandable material The thermal variations generated by the thermistor 11 are transmitted to the mass 9 through the walls of the chamber 30 which, as illustrated in the detail designated with A, can

  advantageously be provided with a pressure screw 31, by adjusting the position

  tion of which it is possible to modify the interior volume of the box

  tier which contains the heat-sensitive mass 9 The part lh of the body 1, made of an electrically insulating material, is crossed by the electrical terminals lla of the PTC thermistor 11 and preferably comprises a threaded housing for a compensation screw 28 which acts on a washer spring 29 mounted in contact with the thermistor 11 in order to ensure perfect contact of the latter with the metal skirt of the housing 30 The reference 34 designates a rigid diaphragm crossed by a piston 35 which, against the reaction of the spring 37 and under the thrust of the mass 9, exerts, through the elastic membrane 38, a pressure on the second diaphragm

  elastic 32 which thus intercepts the passage light 4 h from the fitting 4.

  In the variant illustrated in FIG. 7, the characteristics which come from

  nent to be described remain unchanged except for the thermis-

  tance (CTP) 11, which is made in the shape of a cap so as to

  marry the outer surface of the housing 30 which contains the mass 9.

  In the variant illustrated in FIG. 8, the thermistor (PTC) 11

  is shaped like a bowl The screw 28 and the washer spring act

  advantageously feels on the housing 30 instead of on the thermistor,

  so as to be able to compensate for the axial displacements likely to be

  generated by thermal variations between the elastic membrane 36 and the rigid diaphragm 39 The piston 35 which passes through the second diaphragm

  rigid 34 controls, against the reaction of the spring 37, a valve which

ra have any shape.

  - In the variant illustrated in FIG. 9, the thermistor (PTC) It is embedded in the mass 9 contained in the cap case 30, as described for

  figure l The thermo-volumetric variations of mass 9 are trans-

  put on the elastic membrane 36 and then on the second corrugated elastic membrane 32 which acts on the piston 35 The valve may be of the two type

  or three-way designated with 3, 4, and 4 c.

  In the variant shown in FIG. 10, the piston 35 is absent,

  so that the second elastic membrane is shaped so as to control

  directly pass the 4h passage light of fitting 4, as described for

variant of Figure 6.

  In the structural variants of the valve according to the invention, illus-

  trés by Figures 6 to 10, we have, as we can see in these same figures, hermetically separated the housing 30 containing the heat-sensitive mass 9 of the valve body This structure makes it possible to prevent / En effect,

  infiltrations, even minimal, can reach mass 9 if the fluid

  controlled is a hot and corrosive gas, such as for example the well-known gas

  under the name "FREON 12", commonly used in refrigeration circuits

  with the ration closed, any infiltration of this same gas into the chamber containing the thermosensitive mass 9 and possibly the thermistor 11, would have the effect of damaging these same organs and putting the valve practically out of service.

  In the light of the above description, the advantages obtained

  through the use of the valve according to the invention are evident While in hand-

  taking the principle of having as co-operating thermistor

  rant with a heat-sensitive mass wax or other suitable material, whether or not added with metal powders or oxides having a high thermal conductivity, the valve according to the invention may, whatever its shape and structure, be made with direct control (Figures 1 to 5) or indirectly controlled with a sealed chamber containing the heat-sensitive mass (Figures 6 to 10), as well as with an external thermistor (Figures 4 to 8) or else with a thermistor interior

  (Figures 9,10) suitably arranged and shaped.

  The valve according to the invention achieves the following main goals: operational safety for a very long time;

  significant savings on cost prices compared to electors

  current tro-valves associated with relays and / or other high cost devices; advantageous use mainly on washing machines and refrigerating machines; wide scope wherever it is necessary to control

pressurized fluids.

he -

Claims (12)

R E V E N D I C A T O N S   1 Thermo-electric valve, in particular for washing machines and / or for refrigeration machines, comprising a hollow body in which a valve in the closed or open position controls a passage light for water or for any other liquid and cooperates with an elastic member, characterized by the fact that the movable member of the valve is controlled to close or open the light under control by the pressure generated in   a closed chamber containing a given volume of wax or other suitable material   required heat expandable as well as one or more thermistors (PTC) electrically connected to a programming or timing device of the machine; when supplied with electric current, said   thermistors raising the temperature of the mass of wax which,   In this way, increases in volume by generating a high pressure in this same chamber, which pressure exerts, through seals and / or membranes   sealing elastic, a thrust which is transmitted to the sealing member   valve which is thus moved to an open or closed position, keeping it against the action of elastic means as long as   or the thermistors are supplied with electric current.   2 thermoelectric control valve according to claim 1, charac-   terrified by the fact that it comprises, inside a hollow body, a valve provided with a cylindrical rod slidably mounted longitudinally in a corresponding housing in which is also mounted at least one seal (fig 1) and communicating with a sealed tight chamber   of an expandable material under the effect of the heat generated by one or more   several thermistors embedded in the same material (wax) and crossed by electrical terminals which extend to the outside of this same chamber. 3 valve according to claim 1, characterized in that the thermistors are mounted outside the chamber containing the wax (fig 3 to 8).   4 valve according to claim 1, characterized in that the   elastic means which cooperate with the valve are constituted by a res- lamellar or helical.   Valve according to claim 1, characterized in that the chamber containing the wax is constituted by a metal housing suitable for   quickly dissipate the heat generated by the thermistor (s).   6 Valve according to any one of the preceding claims, ca-   characterized by the fact that its opening is controlled by independent means   dependent on the pressure of the incoming water or fluid, so that   allow the liquid to enter the machine even with low pressure   in the supply network.   7 valve according to claim 1, according to a variant characterized in that the rod which controls the axial movement of the valve   is inserted by one of its ends in the latter with a long play   gitudinal with a prefixed length, in order to compensate for possible pressures coming from the chamber containing the wax and due to an expansion of the latter caused by the ambient operating temperature of the valve (fig 4).   8 valve according to claims 1 and 7, characterized in that   in the longitudinal space provided between the end of the rod and the housing   When the latter is inserted into the valve, there is a spring   sliding by compression (fig 5), able to avoid water hammer.   9 thermoelectric control valve according to claim 1, charac-   terrified by the fact that the hollow part of the valve body through the   which pass the fluid under control is hermetically separated from the chamber containing the mass expandable with heat, and associated door the thermistor,   outside or inside said chamber.   Valve according to claims 1 to 9, characterized in that   that the separation of the different chambers in the valve body is   obtained by means of elastically deformable membranes.   11 Improvement to thermoelectric valves according to the claims   1 and 10, characterized in that the diaphragm which separates the cham-   bre containing the heat expandable mass and possibly the thermistor   (CTP) of the rest of the valve is constituted by an elastically deformed lamella   Mable which cooperates with an elastomeric thermo-resistant and electric membrane only insulating.   12 Improvement according to claims 1 and 12, characterized in that the elastically deformable strip which constitutes the diaphragm for separating said chambers is shaped so as to be able to intercept the orifice of the fluid outlet connection and acts as a shutter for valve.   13 Thermoelectric valve according to claim 1, characterized in that the elastically deformable diaphragm cooperates with a stem valve which controls one or more outlet lights against the   reaction of tared elastic means.   14 Thermoelectric valve according to any one of the claims   1 to 13, characterized in that the chamber which contains the heat expandable mass is provided with means allowing its internal volume to be modified in order to modify the intervention characteristics valve.   Improvement according to claim 7, characterized in that the means making it possible to modify the intervention characteristics of the valve consist of one or more pressure screws which can be operated from the outside and projecting towards the inside of the housing   watertight containing the heat expandable mass and possibly ther- mistance.   16 Thermoelectric valve according to any one of claims   above, characterized in that the heat expandable mass   consists of a wax-based element mixed with metal powders   liquids and / or with oxides with high thermal conductivity.