ES2229566T3 - SOLENOID VALVE. - Google Patents

Abstract

Solenoid valve, comprising: - a core element (10) having a coil (12) to magnetize said core element (10); and a component (14) having at least one permanent magnet (16) to define a first and a second magnetic pole zones of said component (14); said component (14) and said core element (10) are arranged so that a relative displacement between said component (14) and said core element (10) is possible; stop means (18, 20) for limiting the relative displacement of said core element (10) and said component, between a first and a second limit stop positions; said stop means (18, 20) being arranged so that - in said first stop limit position (L) a pole area of said core element (10) is located, in said first magnetic pole area of said component and is pushed towards said stop means (18) to provide said first stop limit position by magnetizing said permanent magnet (16), and - at said second stop limit position (R) said pole area of said core element (10) in said second magnetic pole zone of said component (14) and is pushed towards said stop means (20) to provide said second stop position by magnetizing said permanent magnet (16); - a valve chamber (22) is provided with an inlet (24) and a series of outputs (26); and - a valve element (28, 30) located in said valve chamber (22) is movable to selectively couple said inlet (24) with at least one of said outlets (26); and - means (28) are provided for actuating said valve element (28, 30) by means of said relative displacement of said core element (10) and said component.

Description

Solenoid valve

Technical sector to which the invention belongs

The present invention relates to a valve solenoid for control, for example, of the fluid supply refrigerant in multi-compartment refrigerators that they have a fridge and a freezer, and use only one compressor.

Technical background

Refrigerators for domestic applications or commercials are usually designed to provide in the same appliance a freezer compartment and a compartment fridge. This is achieved by using two circuits of independent cooling with two compressors or a single circuit refrigeration with a compressor working together with a solenoid valve that has the function of diverting the refrigerant to the compartment that requires cooling. To save space, limit energy consumption and reduce the cost of the device, the single compressor solution with a bypass valve is the preferred solution, although, as explained below, it presents some limitations with respect to a system with two compressors

Figure 1 describes a typical system of refrigeration comprising a single compressor (100), a condenser (102), a first evaporator (104), placed for example in the freezer compartment, and a second evaporator (106), placed for example, in the refrigerator compartment.

As shown in Figure 1, a valve solenoid (108) deflects the refrigerant fluid from the outlet of the condenser (102) to freezer evaporator (104) or evaporator of the refrigerator (106) through the capillary restrictions (110) or (112), respectively. The solenoid valve (108) is actuated through a drive element (114) such as a coil magnetic, and the current supply to the coil is controlled by means of a control unit (116).

The first operating position of the valve (108) is a first working position indicated in the Figure 1 through a continuous line (a), in which the output of the condenser (102) is connected to the first evaporator (104). Another line dashed (b) in figure 1 refers to a second position of work in which the output of the capacitor (102) is connected to the second evaporator (106).

Figure 1 represents an application in which the two evaporators (104), (106) are fed independently with refrigerant depending on the working position of the valve of solenoid.

As shown in figure 1, in the first working position, the cooling fluid expands in the first evaporator (104) through the ducts (110), (118), and returns to the compressor (100) along the paths (120), (122). In the second working position, the fluid expands in the second evaporator (106) through the ducts (112), (124) and return to the compressor along the trajectories (126), (122).

An alternative application not shown explicitly in figure 1 is one in which both evaporators (104) and (106) are fed with cascading refrigerant in the first work position. In this case, both evaporators may not They can be operated independently.

However, the cooling system shown in figure 1 it presents the disadvantage of not allowing the supply simultaneous coolant to both the first and second evaporators (104) and (106). It is often required in applications the need for simultaneous cooling of the compartments of the freezer and refrigerator, and therefore, simultaneous supply of refrigerant This represents a system limitation. compressor.

In addition, in the document US-A-5,394,131, a bistable magnetic drive with mounted armor, consisting of a high-grade permanent magnet in the form of a disk with two properly shaped and movable pole pieces laterally outside the coil, transversely to its inner axis, one piece of electromagnetic ring pole between two pole pieces of electromagnetic stop.

In addition, in document DE 41 17 958 A1, describes a magnetic valve that has a valve chamber and a valve piston, which are movable between two stop elements to open and / or close at least one valve opening.

In addition, in the document US-A-5,226,627, a magnetic valve that has a valve chamber at least with a valve opening, a valve component adapted to close and release at least the opening in its position of Contact. The magnetic valve further comprises an element of moveable action between two extreme positions in the chamber of valve and acting the valve component also like a magnet permanent associated with the acting element and holding the element of action in extreme positions.

In addition, in the document US-A-3,379,214, a valve assembly, which includes a body that has an inlet and an outlet and a flow passage, including a valve chamber among them. A single electromagnet is supported on the body, and the valve element of the valve chamber is movable between a first and second flow control positions to control fluid flow

In addition, in the document US-A-4,577,832, a rotary drive apparatus having a tubular sleeve in which a stator has a pair of separate pole pieces circumferentially and a rotor that has a pair of pole pieces radially separated. The rotor or stator is manufactured in the form of permanent magnet. The device has a coil to magnetize the another one of said rotor and stator.

In addition, in the document US-A-4,546,338, a rotary drive apparatus suitable for use in a flow control valve equipped with a rotor valve, swivel, mounted in a housing. The rotor valve is connected to a permanent magnet component. Means are provided stop to allow limited rotating rotor movement between a first position and a second position.

In addition, in the document US-A-4,647,009, a electromagnetic rotating drive device that includes a permanent magnet rotor disposed in a hole formed in a stator core block drilled, made of material magnetic.

Characteristics of the invention.

Given the above, the object of the invention is provide a solenoid valve that allows feeding different evaporators, or individually, or simultaneously.

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According to the present invention, this objective is achieved through a three-state solenoid valve that has the characteristics of the

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Accordingly, according to the present invention, implements a three-state solenoid valve using a core element that has a coil to magnetize said core element. In addition, a component with a permanent magnet, at a minimum, which defines a first and a second pole zone magnetic is arranged with respect to the core element so that a relative movement between the component with the Permanent magnet and core element.

In addition, the solenoid valve comprises means stop to limit the relative movement of the core element and the component with a permanent magnet, at least, between a first and a second limit stop positions. According to this invention, different work positions are stable in solenoid valve without other power supply to the coil in the core element that, in other words, receives tension only to move the element with the magnet or magnets permanent

No power supply is necessary to keep this component in one of several work positions. According to the present invention, this is achieved because in each of the different work positions, the magnetic field flow of the permanent magnet is closed by the core element, which It therefore maintains a stable state.

In addition, the stop means limit movement relative of the core element and the component, between a first and a second limit stop positions. In each stop position, the component that has a permanent magnet, at a minimum, is shifts slightly out of the relative equilibrium position in that the flow of its magnetic field closes completely on the core element. Therefore, there is the tendency of component that has the permanent magnet or magnets to scroll to Your equilibrium position. However, as the component with a permanent magnet or magnets, makes contact with the stop means, there is a force or torque generated in each of the first and second limit stop positions.

Functionally, the component with the magnet permanent moves relative to the core element to the first limit stop position through the supply of a current pulse with a first polarity appropriate to the coil of the core element. In addition, the component with the permanent magnet functionally moves to the second limit stop position a through the supply of a current pulse with a polarity opposite to the polarity assigned for the first position limit of stop, top, maximum as a noun, top as an adverb. In case the component with the permanent magnet is due move to a third position between the first and second limit stop positions, this is achieved through the supply to the coil of a sequence of polarity pulses alternate

Therefore, in other words, the different work positions are generally selected at excite the coil with short, positive or negative impulses, generated in a control unit, to carry the element of valve from the first to the third working positions. In In particular, the third work position is obtained through supply to the coil of a short sequence of alternating pulses of calibrated energy. In this case, the amount of energy to getting the third job position is determined as a function of the inertia and self-resonance characteristics of the solenoid valve

According to a preferred embodiment of the present invention, the component with the permanent magnet is provided with pole extensions in contact with permanent magnet poles to get an optimized interaction between the permanent magnet and The core element.

Still according to another preferred embodiment of the present invention, the solenoid valve uses a rotor as component with a permanent magnet, and core elements with two separate pole pieces facing each other, to form a rotor space for rotor accommodation. Preferably, the pole extensions in contact with the permanent magnet poles will extend beyond the permanent magnet in a radial direction of the rotor.

This preferred embodiment of the invention allows applying the basic principle indicated above to a Rotating arrangement of a solenoid valve. In particular, the geometry of the pole pieces and the pole extensions are important to determine the direction and magnitude of the torque generated in the rotor by the pole pieces in conditions stationary and in case the coil is energized.

In addition, a shaft shaped is typically provided bar, integrated with the cylindrical rotor to rotate with the rotor, so that the shaft extends inside the valve chamber and It has a sealing element to close at least one of the outputs in the valve chamber, in accordance with the position of the rotor.

A feature of this embodiment preferred, which implements a solenoid valve of the type rotating, is the low friction during movement and by consequently the reduction of the possibility of "stuck" or, in in other words, the possibility of not moving to the position of Desired work due to excessive friction.

According to another preferred embodiment of the present invention, the component is implemented as a sliding element adapted to carry out an external line movement relative to the core element. In this case, the pole extensions of the sliding element comprise, for example, a first part in U-shaped and a second U-shaped part, contained in the first U-shaped part, and the parts being arranged in U-shaped contact with magnet related pole faces permanent.

Therefore, this other embodiment preferred of the present invention allows a linear movement in Rotary location, inside the solenoid valve.

According to another preferred embodiment, regardless of the rotating or linear movement of the element With the permanent magnet, this permanent magnet element is a sintered piece made with Ne-Fe-B (neodymium-iron-boron). Preferably, I would combine the function of the magnet in a single piece permanent, the pole extension, the rotor and the shaft attached to the rotor, making it possible to reduce the number of pieces of, for example, four to one This can be achieved using plastic material loaded with ferrite that would be magnetized next. With this type of functionality combined should pay attention to the chemical compatibility of the supply, for example, fluids of refrigerant and / or lubrication used in the system to avoid its pollution and / or degradation of the plastic material of the valve.

According to another preferred embodiment, the materials Suitable for the single piece that has a number of functions are, for example, families of plastics materials from poly-oxymethylene (POM) or poly-aryl ether ketone.

In what follows, the preferred embodiments, that should not be construed as restricting the scope of the This invention will be described with reference to the attached drawings, in which:

Figure 1 shows a schematic diagram of a single compressor cooler system, which has two evaporators which are supplied independently of each other;

Figure 2 shows the basic principle that bases the different embodiments of the present invention;

Figure 3 shows a basic construction for a solenoid valve of the rotating type according to a first preferred embodiment of the present invention;

Figure 4 shows a stable first position working on the solenoid valve of the rotating type, shown in figure 3;

Figure 5 shows a second stable position working on the solenoid valve of the rotating type, shown in figure 3;

Figure 6 shows a stable third position working on the solenoid valve of the rotating type, shown in figure 3;

Figure 7 shows the basic structure of a solenoid valve of the linear movement type, according to a second preferred embodiment and also a first position Stable working of this solenoid valve type linear movement;

Figure 8 shows a second stable position Working solenoid valve of linear motion type, shown in figure 7;

Figure 9 shows a stable third position Working solenoid valve of linear motion type, shown in figure 7;

Figure 10 shows a first circuit for provide the alternate pulse of calibrated energy for the activation of solenoid valves, according to the present invention;

Figure 11 shows a second circuit of control for the supply of alternating currents for activation of the solenoid valves, according to the present invention; Y

Figure 12 shows a third circuit of control for the supply of alternate pulses for activation of the solenoid valves, according to the present invention.

Basic principle underlying the present invention

Figure 2 shows the basic principle that based solenoid valves according to the different embodiments of the present invention; it should be noted that while Figure 2 refers to a rotating type of solenoid valve, The basic principle described with respect to it may also be easily adapted to a solenoid valve of the type linear movement, as indicated below.

As shown in Figure 2, the approach which underlies the present invention depends on three positions stable or equilibrium states of a provision comprising, at least one core element (10) having a coil (12) and a component (14) that has a permanent magnet (16). The magnet permanent defines first and second magnetic pole zones (N) and (S), respectively, of component (14). In addition, the component (14) and the core element (10) are arranged so that it is possible relative displacement between component (14) and the core element (10).

As Figure 2 shows, this arrangement It allows three stable work positions. In the first position shown on the left side, the magnetic field flux of the permanent magnet (16) closes at the bottom of the element core (10), while the pole (N) and (S) areas of the magnet permanent are arranged symmetrically with respect to the axis core element core.

In addition, in the second work position shown in the central part of figure 2, the field flow Magnetic permanent magnet (16) is closed, so that it closes again by the core element, however, with a first pole zone, for example, the pole (N) that tends to align with the central axis of the core element (10).

Additionally, in the third stable position of work shown on the right side of figure 2, the flow of magnetic field is also closed on the core element (10), however, this time with the other piece of magnetic pole, for for example, the pole (S) that tends to align with the central axis of the core element.

It is important to note that all these three work positions are maintained without a continuous supply of coil power (12). The reason for the coil (12) is to get a transition between different work positions. Until at this time, it was necessary to temporarily excite the coil to achieve a magnetization of the core element (10) that is not kept permanently.

An option could be, for example, for a transition from the left working position to the central working position, that the pole piece of the element of core (10) is temporarily changed to pole (S) so that it is the magnetic pole area (N) of the permanent magnet (16) is attracted.

Equivalently, to get a transition between the work positions on the left and the right shown in figure 2, the bottom of the element of core (10) should be temporarily magnetized to a pole magnetic (N.) to attract the magnetic pole area (S) of the magnet permanent (16).

Still further, it should be mentioned that the three different work positions shown in figure 2 have a natural tendency to achieve a stable position where exert other forces or pairs on the component with the magnet permanent.

However, for the indicated applications above with respect to the prior art of the present invention, it might be necessary that, in particular, in center and right work positions, the component with the permanent magnet is not only kept in a stable state but also to exert a certain force or torque on others construction elements of the solenoid valve.

For this reason, a stop may be provided. left or first (18), and a right or second stop (20). These stops (18), (20) allow to limit the movement of the component (14) with permanent magnet so that, in the work positions center and on the right the component (14) does not move from the state current balance but is abruptly stopped before Reach this state.

Likewise, a trend of component (14) to also move to the steady state shown in the center and right position of figure 2. This tendency to move will also result in a pair that is exercised through component (14) on the elements of the construction that are connected to him.

Description of preferred embodiments

In the following, the basic principle indicated in Figure 2 will be described in greater detail for a valve rotor type solenoid and linear movement type. Along from the following description, those elements that are related to those described with respect to figure 2, it denominate using the same reference numbers for facilitate explanation

As shown in figure 3, the valve rotor solenoid comprises a core element (10) and the coil (12) for excitation of the core element (10). Further, a valve chamber (22) is provided to which fluid is supplied through an entrance (24). The fluid can then leave the chamber of valve (22) through a first outlet (26) and a second valve outlet (not explicitly shown in figure 3).

As also shown in Figure 3, the component (14) with permanent magnet (16) (visible in figure 4) it is connected by an axis (28), which has an element of sealed (30) attached to it, to close the outputs of the chamber valve according to the working position of the rotor (14).

Finally, to change the positions of different work, the core element is excited through the coil (12) by supplying current to it, through the terminals (32), (34), respectively.

Figures 4 and 5 show other details of the rotor type solenoid valve, with a sectional view transverse through solenoid valve. In addition, the figures 4 to 6 refer to work positions other than component (14) with permanent magnet (16).

As shown in Figures 4 to 6 for the rotor type solenoid valve, core element (10) It has a specific structure with two separate pole pieces, facing each other to form a rotor space between them, to accommodate the component (14) with the permanent magnet.

In this case, the component (14) is a rotor that it comprises the permanent magnet (16). In addition, the rotor (14) comprises pole extensions (34), (36) in contact with the magnet poles permanent (16) to achieve an optimized interaction between the permanent magnet (16) and the core element (10).

The core element (10) has two pieces of separate pole (10-1), (10-2), facing each other, to form a space for the rotor between them to receive the rotor. Also, the pole extensions (34), (36) extend beyond the permanent magnet and have two recesses concave that are diametrically opposed. The shape of the recesses and the pole extensions are chosen so that the valve of solenoid is optimized with respect to certain conditions of operation, for example, the torque that should be exerted on the sealing element to close each of the outputs of the camera.

Functionally, the solenoid valve of the type rotor that has the structure shown in figure 3, has three stable work positions shown in figures 4 to 6. In particular, each of the work positions shown in the Figures 4 to 6 correspond to the left work positions, center and right shown in figure 2.

However, while in figure 2 the principle basic of the present invention has been explained with the element of core having only one pole, according to the solenoid valve of the type rotor, two pole pieces are arranged to increase the magnitude of torque that can be exerted through the component with the magnet permanent.

As previously indicated with with respect to figure 2, the different work positions shown in figures 4 to 6 differ in the way in which the flow of the magnetic field concatenates the magnetic circuit. For better identify the various job positions a black dot at one end of the permanent magnet (16).

The first work position is related to the left working position shown in figure 2, in which the magnetic flux of the permanent magnet (16) is concatenated by the pole unique to the core element, that is, through (10-1) and (10-2).

In addition, according to the work position shown in Figure 5, the component (14) has its hourly rotation limited by the sealing element (30) that rests against one of the outlets of the valve chamber shown in figure 3. With the coil without tension, the permanent magnet flow (16) flows from the side lower than upper as shown by the arrows in figure 5, it is say, in the south / north direction.

Because the rotor is forced to stop by the sealing element (30) at an angle (α1) with respect to the vertical axis, the magnetic flux is somewhat deviated from the point of equilibrium that will correspond to the magnetic flux lines running along a straight line from north to south.

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This constitutes a deliberate measure to generate a torque clockwise to ensure that the sealing element (30) keeps the corresponding outlet closed, with a given magnitude of force. In addition, in the event that the coil is excited, for example, by means of a current that generates an upper pole piece with southern polarity and a lower pole piece with northern polarity, an even stronger hourly torque that maintains the component can be generated (14) in the position shown in the

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Figure 6 represents the situation corresponding to the central work position shown in the Figure 2, with the sole difference that in this case the pair is generates counterclockwise to close another of the outputs of the valve chamber shown in figure 3.

Reversing the polarity of the current of the coil (12), the upper and lower pole pieces of the element of core (10) will also reverse its magnetic polarity by subjecting the element with permanent magnet at a clockwise or counterclockwise turn due to the attraction / repulsion effect that the pole pieces (10-1), (10-2) exercise on the pole extensions (34), (36).

Consequently, the rotor (14) takes the position illustrated in one or the other of figures 5 and 6, at which time it coil excitation may end. In both positions, the sealing element (30) rests against the valve outlets to stop at one or the other of the angles (? 1) or (? 2), in relation to the vertical axis. In both positions you get a force of the sealing element (30) against each chamber outlet valve to deliberately maintain the flow of the lines of magnetic flux diverted to generate a clockwise or counterclockwise pair on the sealing element.

As shown in Figure 4 and it has been indicated above, the rotor (14) can also take a third work position corresponding to the left position shown in figure 2, which is among those shown in the figures 4 and 6. In this central working position, the permanent magnet (16) it is oriented substantially vertically with the flow lines magnetic concatenated by adjacent pole pieces (10-1), (10-2). In this position of work, both valve outlets are open allowing it to supply the fluid to the valve chamber and then can exit to through both valve outputs at the same time.

Next, a valve will be explained solenoid according to the type of linear movement and second embodiment of the present invention, referring to Figures 7 to 9. In these figures 7 to 9, the functional units that have the same function, as indicated above, are called using The same reference numbers.

As shown in Figure 7, the element Valve (14) is a sliding element adapted to carry perform the alternating linear motion relative to the core element (10), in the valve chamber (22). For solenoid valve Linear movement type, the pole extension of the element Slider comprises a first U-shaped part (38) and a U-shaped second part (40), which goes outside with the first part (38) in the form of U. The parts (38), (40) in the form of U are in contact with the pole faces of the permanent magnet (16). The core element (10) comprises a yoke (10) that carries the coil (12) and the end of the U-shaped yoke is faced with the end of the pole extensions (34), (40) U-shaped, of the component with permanent magnet.

As shown in Figure 7, in the center position of solenoid valve, magnetic flux generated through the permanent magnet is guided to the pole piece of the yoke (10) by means of the U-shaped parts (38), (40), respectively, and closes by means of single pole pieces (10-1), (10-2) of the yoke, without power supply to the coil (12).

As shown in figure 8, to carry the solenoid valve and the valve element included therein to the position with the left exit closed from the chamber of valve (22), the yoke is magnetized so that the pole piece (10-1) presents, for example, polarity S and the part of pole (10-2) presents polarity N. In consequently, an attractive force is exerted on the left side on the U-shaped part (38), upper, and a force of repulsion on the bottom (40) U-shaped. consequently, a repulsive force is exerted on the right side between the pole piece (10-1) of the yoke (10) and the U-shaped upper part (38) and other force of attraction at the bottom (40) U-shaped. Once the valve element moves to a position where the outlet left closes, no more power will be supplied to the coil (12) and the magnetic flux will close along the dashed line shown in figure 8, to maintain this position as a position stable work.

The same principles indicated with respect to figure 8 apply to figure 9 relative to the right exit valve chamber closed (22). The only difference is that in this case the pole pieces (10-1) and (10-2) have inverted magnetic polarities for moving the component (14) to the right side.

Again, once the exit has been closed right of the valve, the magnetic field flow generated by the permanent magnet (16) closes along the dashed line shown in figure 9 to maintain the working position without further power supply to the coil (12).

In what follows, different ones will be explained approaches to control the supply of impulses to the coil (12) for a transition of the component (14) between the different Working positions for both solenoid valve type rotor as for the linear movement type.

An alternating current pulse is sent to the coil (12) to carry the component (14) with the permanent magnet (16) to the central work position, according to the left side of the Figure 2, starting from one of these stable positions shown in the central part and in the right part of figure 2. The energy of the alternating pulse is calibrated so that it is strong enough to move the component (14) from one of the stable positions shown on the center and right side of figure 2 (or shape equivalent, in figures 5, 6 and figures 8, 9, respectively) but weak enough to exclude a complete displacement from one of the left or right work positions, and vice versa. This means that, the energy will be weak enough to allow a swing around the central position, in whose moment the supply of alternate impulses ends, with the component (14) stabilized in the central position shown in the Figures 4 and 7.

In addition, the duration of power and energy of Alternate impulses is a function of the inertia of the component (14), that is, the rotor or the sliding element, and also of the auto-resonance of the solenoid valve. Because the rotor or sliding element have the tendency to stabilize in the central working position, the parameters of Alternate impulses allow frankly broad tolerances. Other additional factor that stabilizes the position is the dynamic effect of the fluid flow in the central position simultaneously through of both outputs acting as a buffer to extinguish the residual oscillations if there still were.

Examples of alternate impulses from calibrated energy and a corresponding control circuit for its generation referring to figures 10 to 12.

Figure 10 shows a control circuit adapted for the provision of a conventional selector that allows progressively reach decreasing voltages or impulses of full wave current. In position (A), only one positive impulse to the diode (D1) and passes through the capacitor (C1), and other current impulses are prevented as long as the capacitor (C1). In addition, in position (B), you can send a only negative impulse to the diode (D2) and then through the condenser (C2). Again, other current impulses are avoided in both the capacitor is charged (C2). Finally, in position (C), AC pulses are sent to energize the coil. The damping amplitudes of alternating current pulses is achieved through a heated PCT thermistor and reducing the current at a negligible value after a short time. This results in a progressively reduced tendency to oscillate around the central position.

Another option shown in Figure 11 refers to an electronic controller in which a coil (L) is operated with alternating current through the thyristors (T1) and (T2). In the position (A), the control unit activates a single half-wave positive. In position (B), the control unit activates only one Negative half wave. In position (C), to activate the thyristors (T1), (T2) are sent alternate half-waves divided in sequence, of so that the energy is calibrated through a selection of the timing in which the thyristors are activated (T1), (T2).

Another option for electronic control is shown in figure 12 and refers to a coil (L) driven by direct current through a FET bridge of field effect transistors. In position (A), a positive impulse by driving transistors (A) and (D) of field effect In this case, the pulse length is determined selectively through a logic circuit. Also in position (B), a negative impulse is generated by actuating the transistors (B) and (C) of field effect. Again, the length of the Pulse is determined selectively through a logic circuit. Finally, in position (C), alternate pulses are activated positive / negative in sequence. Again, the pulse length, frequency and duration are determined by a logic circuit to send a calibrated amount of energy.

Regardless of the different embodiments indicated above, the permanent magnet can be made with a sintered piece, for example, of Ne-Fe-B (neodymium-iron-boron) or with a single piece of plastic loaded with ferrite that combines the functions of permanent magnet and associated extensions of magnetic pole. Ferrite loaded materials known for their stability chemistry are, for example, plastics families of poly-oxymethylene (POM) or poly-aryl-ethyl ketone.

Also, regardless of the different embodiments indicated above, the operation of the solenoid valve is obtained by exciting the coil with pulses short circuits, whose positive, negative, or alternating nature define the position of the valve element once the coil tension.

Claims (15)

1. Solenoid valve, comprising: a core element (10) having a coil (12) to magnetize said core element (10); Y a component (14) that has at least one permanent magnet (16) to define a first and a second zone of magnetic pole of said component (14); said component (14) and said core element (10) so that a relative displacement between said component (14) and said element core (10); stop means (18, 20) to limit the relative displacement of said core element (10) and said component, between a first and second position limits of stop, top, maximum as a noun, top as an adverb; said stop means being arranged (18, 20) so that - in said first limit stop position (L) a pole zone of said core element (10) is located, in said first magnetic pole zone of said component and is pushed towards said stop means (18) to provide said first limit stop position by magnetizing said magnet permanent (16), and - in said second limit stop position (R) said pole area of said core element (10) is located in said second magnetic pole zone of said component (14) and is pushed towards said stop means (20) to provide said second stop position by the magnetization of said magnet permanent (16); - a valve chamber (22) is provided with a input (24) and a series of outputs (26); Y - a valve element (28, 30) located in said valve chamber (22) is movable to couple selectively said input (24) with at least one of said departures (26); Y - means (28) are provided for actuating said valve element (28, 30) by means of said displacement relative of said core element (10) and said component (14); characterized in that said solenoid valve is a three state solenoid valve, said core element being arranged (10) and said component (14) so that there is a third position of stop (M) of said core element (10) and said component (14), in whose position - said pole area of said core element (10) is partially located in said first pole area magnetic of said component (14) and partially in said second magnetic pole zone of said component (14) so that said third relative position is stabilized because the magnetic flux of said permanent magnet (16) is closed by said element of nucleus. 2. Three-state solenoid valve according to claim 1, characterized in that the component (14) is also provided with pole extensions (34, 36) in contact with the poles of said permanent magnet (16) to achieve an optimized interaction between the permanent magnet (16) and the core element (10). 3. Three-state solenoid valve according to claim 1 or 2, characterized in that the component (14) is a rotor. 4. Three-state solenoid valve according to claim 3, characterized in that said core element (10) has two separate pole pieces (10-1, 10-2) facing each other to form a rotor space between them, to accommodate the rotor. 5. Three-state solenoid valve according to claim 4, characterized in that said pole extensions (34, 36) in contact with said poles of said permanent magnet (14) extend beyond the permanent magnet (16) in one direction radial rotor. 6. Three-state solenoid valve according to one of claims 3 to 5, characterized in that said valve element includes an axis (28) attached to the rotor (14) to rotate with the rotor, said axis extending in the valve chamber (22), and having a sealing element (30) for closing at least one of said outlets of said valve chamber (22) in accordance with the position of said rotor. 7. Three-state solenoid valve according to claim 6, characterized in that said sealing element (30) and said valve chamber (22) are arranged so that the displacement of said rotor is limited between said first and said second positions stop limits, by means of said sealing element (30), which rests against said respective outlets (26) of said valve chamber (22), thereby constituting said outlets (26) said stop means (18, twenty). 8. Three-state solenoid valve according to claim 1 or 2, characterized in that said component (14) is a sliding element adapted to carry out a linear alternating movement in relation to said core element (10). 9. Three-state solenoid valve according to claim 8, dependent on claim 2, characterized in that said pole extensions of said sliding element (14) comprise a first U-shaped part (38) and a second part (40 ) U-shaped accommodated within said first U-shaped part, said U-shaped parts being arranged in contact with the respective pole faces of said permanent magnet (16). 10. Three-state solenoid valve according to claim 9, characterized in that said core element (10) comprises a U-shaped yoke carrying the coil (12), the ends of said U-shaped yoke being facing with the ends of said U-shaped pole extensions of said component. 11. Three-state solenoid valve according to one of claims 1 to 10, characterized in that the permanent magnet (16) is formed of ceramic ferrite metal. 12. Three-state solenoid valve according to one of claims 1 to 10, characterized in that the component (16) is formed of poly-oxymethylene (POM). 13. Three-state solenoid valve according to one of claims 1 to 10, characterized in that the component (16) is formed of poly-aryl ether ketone (PEKEKK). 14. Method of operation of a valve three-state solenoid according to any of the claims previous, comprising the stages: a) move component (14) in relation to core element (10) to said first limit stop position (L) through the supply to the coil (12) of a current pulse with a first polarity; b) move the component (14) in relation to the core element (10) to said second limit stop position (R) through the supply to said coil (12) of an impulse of current with a polarity opposite to said first polarity; Y c) move said component (14) in relation to said core element (10) to said third position between said first and second positions limit stops through the supply to said coil (12) of a pulse sequence with polarity alternating and of calibrated magnitude of energy; d) suspend the power supply to the coil (12) once the component (14) has reached the first position limit limit (L), the second position limit limit (R), or the third stop position. 15. Method of operation of a three-state solenoid valve according to claim 14, characterized in that the supply of a pulse sequence with alternating polarity and calibrated magnitude of energy is achieved through a PTC thermistor.