Patent Description:
Presently, an electronic expansion valve includes an electric motor. The electric motor is controlled by a controller to rotate, and drives a rotor to rotate, and rotation of the electric motor is blocked when the electric motor encounters an obstacle during rotation. When rotation of the electronic expansion valve is blocked, the electronic expansion valve will abnormally work if the controller cannot accurately detect rotation blocking and take corresponding measures; or the electronic expansion valve will also abnormally work if the controller wrongly reports rotation blocking information of the electric motor. The rotor of the electronic expansion valve has two rotation directions, is in a rising phase when rotating towards a first direction, and is in a falling phase when rotating towards a second direction. A rotation condition of the rotor cannot be determined by the controller. <CIT> provides a configuration of an electronic expansion valve in which the Hall sensor is arranged at the periphery close to the rotor. When the rotor rotates, the N poles and S poles of the rotor alternately pass by the Hall sensor which generates a periodic feedback signal from which the controller assesses the operating state of the electronic expansion valve including normal operation and rotor blocking.

That is, the rotation condition of the rotor cannot be determined in the electronic expansion valve in the related art.

The main objective of the present invention is to provide an electronic expansion valve which is defined in claim <NUM> and a monitoring method for an electronic expansion valve which is defined in claim <NUM>, so as to solve the problem that a rotation condition of a rotor is able to not be determined in an electronic expansion valve in the related art.

In order to achieve the above objective, according to one embodiment of the present invention, an electronic expansion valve is provided. The electronic expansion valve includes: a frame body, the frame body being provided with an accommodating cavity and a mounting cavity; an induction magnetic ring, the induction magnetic ring being movably arranged in the accommodating cavity in a height direction of the accommodating cavity, and the mounting cavity being at least located on a circumferential outer side of an active area of the accommodating cavity in which the induction magnetic ring is located; and a Hall sensor, there are multiple Hall sensors, at least two Hall sensors of the multiple Hall sensors being located in the mounting cavity and being arranged around a circumferential side of the accommodating cavity, the at least two Hall sensors of the multiple Hall sensors being located at the same height, and the induction magnetic ring being always in a detection range of the multiple Hall sensors.

In an embodiment of the present invention, an included angle X between projections of centers of induction portions of two adjacent Hall sensors of the multiple Hall sensors and a center of the induction magnetic ring in a height direction of the accommodating cavity and a number n of magnetic poles of the induction magnetic ring satisfy: <MAT> a unit of the included angle X being a degree; and N being an integer.

In an embodiment of the present invention, distances between the at least two Hall sensors of the multiple Hall sensors and the induction magnetic ring are the same.

In an embodiment of the present invention, a distance L between centers of induction portions of two adjacent Hall sensors of the multiple Hall sensors, a number n of magnetic poles of the induction magnetic ring and a projection distance r from the centers of the multiple Hall sensors to a center of the induction magnetic ring in a height direction of the accommodating cavity satisfy: <MAT>.

In an embodiment of the present invention, the induction magnetic ring has a rising position and a falling position, and a circumferential side wall of the induction magnetic ring includes an induction surface section, a distance between the induction surface section and an inner side wall of the accommodating cavity being unchanged in an height direction of the accommodating cavity, a projection of a top side of the induction surface section to the multiple Hall sensors being located in the induction portions of the multiple Hall sensors when the induction magnetic ring is located in the falling position, and a projection of a bottom side of the induction surface section to the multiple Hall sensors being located in the induction portions of the multiple Hall sensors when the induction magnetic ring is located in the rising position.

In an embodiment of the present invention, the circumferential side wall of the induction magnetic ring further includes an upper protective surface section located above the induction surface section and a lower protective surface section located below the induction surface section, the upper protective surface section being in arc transition with a top surface of the induction magnetic ring, and the lower protective surface section being in arc transition with a bottom surface of the induction magnetic ring.

In an embodiment of the present invention, a height of the induction surface section is greater than a motion stroke of the induction magnetic ring in the height direction of the accommodating cavity.

In an embodiment of the present invention, the electronic expansion valve further includes drive rotors, where the drive rotors are arranged in the accommodating cavity, the induction magnetic ring is arranged on one side of the drive rotors close to the mounting cavity, the drive rotors drive the induction magnetic ring to rotate, and the drive rotors have a number the same as that of the magnetic poles of the induction magnetic ring.

In an embodiment of the present invention, the multiple Hall sensors are attached to an outer side wall of the accommodating cavity.

In an embodiment of the present invention, the electronic expansion valve further includes multiple fixing frames, where the multiple Hall sensors are attached to the outer side wall of the accommodating cavity by means of the multiple fixing frames, and at least two fixing frames of the multiple fixing frames are attached to the at least two Hall sensors of the multiple Hall sensors in a one-to-one corresponding manner, so as to limit the multiple Hall sensors between the outer side wall of the accommodating cavity and the multiple fixing frames.

According to another aspect of the present invention, a monitoring method for an electronic expansion valve is provided. The electronic expansion valve has drive rotors driving an induction magnetic ring of the electronic expansion valve to rotate and multiple Hall sensors for monitoring the induction magnetic ring, and at least two Hall sensors of the multiple Hall sensors are spaced around a circumferential side of the induction magnetic ring; and the monitoring method for an electronic expansion valve includes: simultaneously collecting, by the multiple Hall sensors, a motion condition of the induction magnetic ring respectively, so as to form moving magnetic field curves; comparing the moving magnetic field curves collected by different Hall sensors of the multiple Hall sensors; and determining motion conditions of the drive rotors according to phase differences and/or periods of the different moving magnetic field curves.

In an embodiment of the present invention, when the motion conditions of the drive rotors are determined according to the phase differences and/pr periods of the different moving magnetic field curves, the motion conditions of the drive rotors at least include whether the drive rotors rotate, the drive rotors being in a rising phase and the drive rotors being in a falling phase.

In an embodiment of the present invention, when the motion conditions of the drive rotors are determined according to the phase differences and the periods of the different moving magnetic field curves, the drive rotors being in the rising phase or the falling phase is determined according to the phase differences of the different moving magnetic field curves; and whether the drive rotors rotate is determined according to the periods of the different moving magnetic field curves.

In an embodiment of the present invention, the electronic expansion valve is provided with an accommodating cavity and a mounting cavity, the induction magnetic ring is movably arranged in the accommodating cavity in a height direction of the accommodating cavity, and the mounting cavity is at least located on a circumferential outer side of an active area of the accommodating cavity in which the induction magnetic ring is located; and the at least two Hall sensors are located in the mounting cavity and being arranged around a circumferential side of the accommodating cavity, and an included angle X between projections of centers of induction portions of two adjacent Hall sensors of the multiple Hall sensors and a center of the induction magnetic ring in the height direction of the accommodating cavity and a number n of magnetic poles of the induction magnetic ring satisfy: <MAT> a unit of the included angle X being a degree; and N being an integer.

In an embodiment of the present invention, a distance L between centers of induction portions of two adjacent Hall sensors of the multiple Hall sensors, a number n of the magnetic poles of the induction magnetic ring and a projection distance r from the centers of the multiple Hall sensors to the center of the induction magnetic ring in the height direction of the accommodating cavity satisfy: <MAT>.

The technical solution of the present invention is applied, and the electronic expansion valve includes the frame body, the induction magnetic ring and the multiple Hall sensors, where the frame body is provided with the accommodating cavity and the mounting cavity; the induction magnetic ring is movably arranged in the accommodating cavity in the height direction of the accommodating cavity, and the mounting cavity is at least located in the circumferential outer side of the active area of the accommodating cavity in which the induction magnetic ring is located; and the at least two Hall sensors are arranged, are located in the mounting cavity, are arranged around the circumferential side of the accommodating cavity, and are located at the same height, and the induction magnetic ring is always located in the detection range of the multiple Hall sensors.

The accommodating cavity is provided, such that the induction magnetic ring is able to move in the height direction of the accommodating cavity, and moreover, the induction magnetic ring is able to further rotate in the accommodating cavity, and arrangement of the accommodating cavity is able to reduce interference of other structural members on motion of the induction magnetic ring, such that the induction magnetic ring is able to work stably. By arranging the at least two Hall sensors, each Hall sensor is able to collect a magnetic field of the induction magnetic ring during motion and form the moving magnetic field curve. By analyzing a relation between the at least two moving magnetic field curves to determine the motion conditions of the drive rotors, whether the drive rotors are in the rising phase or the falling phase is further determined, and whether the drive rotors rotate is able to be further determined. The problem that a rotation condition of a rotor is able to not be determined in an electronic expansion valve in the related art is solved.

The accompanying drawings of the description forming a part of the present invention serve to provide a further understanding of the present invention, and illustrative examples of the present invention and the description of the illustrative examples serve to explain the present invention and are not to be construed as unduly limiting the present invention. In the accompanying drawings:.

The above-mentioned figures include the following reference numerals:
<NUM>, frame body; <NUM>, accommodating cavity; <NUM>, mounting cavity; <NUM>, induction magnetic ring; <NUM>, induction surface section; <NUM>, upper protective surface section; <NUM>, lower protective surface section; <NUM>, Hall sensor; and <NUM>, drive rotor.

It should be noted that examples in the present invention and features in the examples is able to be combined with each other without conflict. The present invention will be described in detail below with reference to the accompanying drawings in conjunction with the examples.

It should be pointed out that all technical and scientific terms used in the present invention have the same meanings as commonly understood by those of ordinary skill in the art to which the present invention belongs unless otherwise indicated.

In the present invention, in the absence of any description to the contrary, orientation words, such as "upper, lower, top and bottom", used are usually used for directions shown in the figures, or used for an upright, vertical or gravity direction of a component itself; and similarly, for the convenience of understanding and description, "inside and outside" refers to the inside and outside relative to contours of the components themselves, but the above orientation words are not used to limit the present invention.

In order to solve the problem that a rotation condition of a rotor is able to not be determined in an electronic expansion valve in the related art, the present invention provides an electronic expansion valve and a monitoring method for an electronic expansion valve.

As shown in <FIG>, an electronic expansion valve includes a frame body <NUM>, an induction magnetic ring <NUM> and a Hall sensor <NUM>, where the frame body <NUM> is provided with an accommodating cavity <NUM> and a mounting cavity <NUM>; the induction magnetic ring <NUM> is movably arranged in the accommodating cavity <NUM> in a height direction of the accommodating cavity <NUM>, and the mounting cavity <NUM> is at least located on a circumferential outer side of an active area of the accommodating cavity <NUM> in which the induction magnetic ring <NUM> is located; and there are multiple t Hall sensors <NUM>, the at least two Hall sensors <NUM> of the multiple Hall sensors <NUM> are located in the mounting cavity <NUM> and are arranged around a circumferential side of the accommodating cavity <NUM>, the at least two Hall sensors <NUM> are located at the same height, and the induction magnetic ring <NUM> is always in a detection range of the multiple Hall sensors <NUM>.

The accommodating cavity <NUM> is provided, such that the induction magnetic ring <NUM> is able to move in the height direction of the accommodating cavity <NUM>, and moreover, the induction magnetic ring <NUM> is able to further rotate in the accommodating cavity <NUM>, and arrangement of the accommodating cavity <NUM> is able to reduce interference of other structural members on motion of the induction magnetic ring <NUM>, such that the induction magnetic ring <NUM> is able to work stably. By arranging the at least two Hall sensors <NUM>, each Hall sensor <NUM> is able to collect a magnetic field of the induction magnetic ring <NUM> during motion and form a moving magnetic field curve. By analyzing a relation between the at least two moving magnetic field curves to determine motion conditions of the drive rotors <NUM>, whether the drive rotors <NUM> are in a rising phase or a falling phase is further determined, and whether the drive rotors <NUM> rotate may be further determined. The problem that a rotation condition of a rotor may not be determined in an electronic expansion valve in the related art is solved.

As shown in <FIG>, the electronic expansion valve further includes drive rotors <NUM>, where the drive rotors <NUM> are arranged in the accommodating cavity <NUM>, the induction magnetic ring <NUM> is arranged on one side of the drive rotors <NUM> close to the mounting cavity <NUM>, the drive rotors <NUM> drive the induction magnetic ring <NUM> to rotate, and the drive rotors <NUM> have a number the same as that of the magnetic poles of the induction magnetic ring <NUM>. The drive rotors <NUM> drive the induction magnetic ring <NUM> to rotate, and the number of magnetic poles of the drive rotors <NUM> is the same as that of the magnetic poles of the induction magnetic ring <NUM>, such that the influence of the magnetic poles of the drive rotors <NUM> on the magnetic field generated by the induction magnetic ring <NUM> may be avoided, so as to ensure that the multiple Hall sensors <NUM> may stably work.

Of course, the induction magnetic ring <NUM> and the drive rotors <NUM> are able to be integrated, such that synchronous rotation of the drive rotors <NUM> and the induction magnetic ring <NUM> is facilitated.

It should be noted that the drive rotors <NUM> drive the induction magnetic ring <NUM> to rotate, the drive rotors <NUM> are connected to the induction magnetic ring <NUM> together, and the induction magnetic ring <NUM> is able to be synchronously driven to move when the drive rotors <NUM> rotate. Or, the drive rotors <NUM> rotate, such that the induction magnetic ring <NUM> rotates; the drive rotors <NUM> are in a rising phase, such that the induction magnet ring <NUM> is in a rising phase; and the drive rotors <NUM> are in a falling phase, such that the induction magnetic ring <NUM> is in a falling phase. That is, motion of the induction magnetic ring <NUM> is able to indicate motion of the drive rotors <NUM>. By analyzing a relation between the multiple moving magnetic field curves, the motion conditions of the drive rotors <NUM> also are determined, whether the drive rotors <NUM> are in the rising phase or the falling phase is further determined, and whether the drive rotors <NUM> rotate is further determined. It should be noted that since rotation directions of the drive rotors are different when the drive rotors <NUM> are in the rising phase and in the falling phase, a phase difference of the two moving magnetic field curves is opposite. When the electronic expansion valve is designed, it is necessary to give whether the drive rotors are the rising phase or the falling phase when which curve precedes. Or, it is necessary to give that the positive or negative phase difference of the two moving magnetic field curves corresponds to the rising phase or the falling phase, so as to determine whether the drive rotors <NUM> are in the rising phase or the falling phase.

With the two Hall sensors <NUM> as an example, one Hall sensor <NUM> is marked as a first Hall sensor, the other Hall sensor <NUM> is marked as a second Hall sensor, and a phase difference is the moving magnetic field curve of the first Hall sensor minus the moving magnetic field curve of the second Hall sensor. The drive rotors <NUM> being in the rising phase is determined when the phase difference of the two moving magnetic field profiles is positive, and the drive rotors <NUM> being in the falling phase is determined when the phase difference of the two moving magnetic field curves is negative. Thus, whether the drive rotors <NUM> are in the rising phase or the falling phase may be determined according to the positive or negative phase difference of the two moving magnetic field curves.

Since the drive rotors <NUM> rotate uniformly, the moving magnetic field curve of the induction magnetic ring <NUM> collected by the multiple Hall sensors <NUM> is regular, a period of the moving magnetic field curve of the induction magnetic ring <NUM> is changed when the drive rotors <NUM> no longer rotate or no longer rotate uniformly, and whether rotation of the electronic expansion valve is blocked is determined by observing the period of the moving magnetic field curve. When the electronic expansion valve is designed, the period of the moving magnetic field curve of the induction magnetic ring <NUM> during normal motion is collected in advance. During working of the electronic expansion valve, if the period of the moving magnetic field curve is less than a period of the moving magnetic field curve of the induction magnetic ring <NUM> during normal motion, rotation of the electronic expansion valve is blocked.

As shown in <FIG> and <FIG>, an included angle X between projections of centers of induction portions of the two adjacent Hall sensors (<NUM>) and a center of the induction magnetic ring (<NUM>) in a height direction of the accommodating cavity (<NUM>) and a number n of magnetic poles of the induction magnetic ring (<NUM>) satisfy: <MAT> a unit of the included angle X being a degree; and N being an integer.

The included angle between the two adjacent Hall sensors <NUM> is determined according to the number n of magnetic poles of the induction magnetic ring, and moreover, how many Hall sensors <NUM> are placed may be also computed. Such an arrangement is able to accurately determine the motion condition of the induction magnetic ring by means of the moving magnetic field curve.

It should be noted that an angle is generally an acute, and therefore a degree of the included angle X is greater than <NUM> degree and less than or equal to <NUM> degrees. Thus, computation of how many Hall sensors <NUM> are placed is facilitated.

A relation between the included angle X and the number n of the magnetic poles is a check function.

Specifically, distances between the at least two Hall sensors <NUM> and the induction magnetic ring <NUM> are the same. Such an arrangement enables the strength of a magnetic field of the induction magnetic ring <NUM> collected by each Hall sensor <NUM> to be the same, and peaks and periods of the at least two moving magnetic field curves are the same, such that determination of the motion conditions of the drive rotors <NUM> is facilitated by means of the at least two moving magnetic field curves.

As shown in <FIG> and <FIG>, a distance L between centers of induction portions of the two adjacent Hall sensors <NUM>, the number n of magnetic poles of the induction magnetic ring <NUM> and a projection distance r from the centers of the multiple Hall sensors <NUM> to a center of the induction magnetic ring <NUM> in a height direction of the accommodating cavity <NUM> satisfy: <MAT>.

A unit of the distance L is a centimeter, and a unit of the projection distance r is a centimeter.

Of course, the distance L and the projection distance r are length units. The units of the distance L and the projection distance r also are length units of millimeters, meters, etc..

Under the condition that the number n of the magnetic poles of the induction magnetic ring <NUM> is determined, there is a linear function between the distance L and the projection distance r. The distance L between the centers of the induction portions of the two adjacent Hall sensors <NUM> is related to the number n of the magnetic poles of the induction magnetic ring <NUM> and the projection distance r from the centers of the multiple Hall sensors <NUM> to the center of the induction magnetic ring <NUM> in the height direction of the accommodating cavity <NUM>, and the distance L between the centers of the induction portions of the designed two adjacent Hall sensors <NUM> is different in the different number n of the magnetic poles of the induction magnetic ring <NUM>.

In an embodiment, the induction magnetic ring <NUM> has a rising position and a falling position, and a circumferential side wall of the induction magnetic ring <NUM> includes an induction surface section <NUM>, a distance between the induction surface section <NUM> and an inner side wall of the accommodating cavity <NUM> being unchanged in the height direction of the accommodating cavity <NUM>, a projection of a top side of the induction surface section <NUM> to the multiple Hall sensors <NUM> being located in the induction portions of the multiple Hall sensors <NUM> when the induction magnetic ring <NUM> is located in the falling position, and a projection of a bottom side of the induction surface section <NUM> to the multiple Hall sensors <NUM> being located in the induction portions of the multiple Hall sensors <NUM> when the induction magnetic ring <NUM> is located in the rising position. The magnetic poles of the induction magnetic ring <NUM> are arranged on the induction surface section <NUM>, and the distance between the induction surface section <NUM> and an inner side wall of the accommodating cavity <NUM> is unchanged in the height direction of the accommodating cavity <NUM>, such that the multiple Hall sensors <NUM> collect the periodically stable magnetic field for determining the motion conditions of the drive rotors <NUM> by means of the moving magnetic field curves. Such an arrangement enables the multiple Hall sensors <NUM> to always detect the induction surface section <NUM>, so as to ensure that the multiple Hall sensors <NUM> is able to monitor the motion condition of the induction magnetic ring <NUM> in real time.

As shown in <FIG>, the circumferential side wall of the induction magnetic ring <NUM> further includes an upper protective surface section <NUM> located above the induction surface section <NUM> and a lower protective surface section <NUM> located below the induction surface section <NUM>, the upper protective surface section <NUM> being in arc transition with a top surface of the induction magnetic ring <NUM>, and the lower protective surface section <NUM> being in arc transition with a bottom surface of the induction magnetic ring <NUM>. Arrangement of the upper protective surface section <NUM> and the lower protective surface section <NUM> is able to protect the induction surface section <NUM>, so as to avoid collision of the induction surface section <NUM> by other structures, thereby ensuring working stability of the induction surface section <NUM>, so as to produce a stable magnetic field. The upper protective surface section <NUM> is in arc transition with the top surface of the induction magnetic ring <NUM>, and the lower protective surface section <NUM> is in arc transition with the bottom surface of the induction magnetic ring <NUM>, and such an arrangement facilitates motion of the induction magnetic ring <NUM> in the accommodating cavity <NUM>, such that scratching of the induction magnetic ring <NUM> against the inner side wall of the accommodating cavity <NUM> is avoided, and working stability of the induction magnetic ring <NUM> is ensured.

Specifically, a height of the induction surface section <NUM> is greater than a motion stroke of the induction magnetic ring <NUM> in the height direction of the accommodating cavity <NUM>. Such an arrangement enables the induction surface section <NUM> to always be in the detection range of the multiple Hall sensors <NUM>, and ensures that the multiple Hall sensors <NUM> is able to detect the induction surface section <NUM> in real time.

As shown in <FIG>, the multiple Hall sensors <NUM> are attached to an outer side wall of the accommodating cavity <NUM>. Such as arrangement facilitates mounting of the multiple Hall sensors <NUM>, and facilitates the same distance between the multiple Hall sensors <NUM> and the induction magnetic ring <NUM>, so as to ensure detection stability of the multiple Hall sensors <NUM>.

It should be noted that the accommodating cavity <NUM> has a cylindrical shape, and the induction magnetic ring <NUM> has a circular pie shape.

The electronic expansion valve further includes multiple fixing frames, where the multiple Hall sensors <NUM> are attached to the outer side wall of the accommodating cavity <NUM> by means of the multiple fixing frames, and at least two fixing frames of the multiple fixing frames are attached to the at least two Hall sensors <NUM> in a one-to-one corresponding manner, so as to limit the multiple Hall sensors <NUM> between the outer side wall of the accommodating cavity <NUM> and the multiple fixing frames. Arrangement of the multiple fixing frames provides mounting positions for the multiple Hall sensors <NUM>, such that the multiple Hall sensors <NUM> are attached to the outer side wall of the accommodating cavity <NUM>. The multiple fixing frames further protect the multiple Hall sensors <NUM>, so as to avoid collision of other structural members on the multiple Hall sensors <NUM>, thereby ensuring stable work of the multiple Hall sensors <NUM>.

The electronic expansion valve has drive rotors <NUM> driving an induction magnetic ring <NUM> of the electronic expansion valve to rotate and multiple Hall sensors <NUM> for monitoring the induction magnetic ring <NUM>, and the at least two Hall sensors <NUM> are spaced around a circumferential side of the induction magnetic ring <NUM>; and a monitoring method for an electronic expansion valve includes: simultaneously collect, by the multiple Hall sensors <NUM>, a motion condition of the induction magnetic ring <NUM> respectively, so as to form moving magnetic field curves; compare the moving magnetic field curves collected by different Hall sensors; and determine motion conditions of the drive rotors <NUM> according to phase differences and/or periods of the different moving magnetic field curves.

By arranging the at least two Hall sensors <NUM>, each Hall sensor <NUM> is able to collect the magnetic field of the induction magnetic ring <NUM> during motion and form a moving magnetic field curve. The motion conditions of the drive rotors <NUM> are determined by analyzing a relation of the at least two moving magnetic field curves. Specifically, when the motion conditions of the drive rotors <NUM> are determined according to the phase differences and/or periods of the different moving magnetic field curves, the motion conditions of the drive rotors <NUM> at least include whether the drive rotors <NUM> rotate, the drive rotors <NUM> being in a rising phase and the drive rotors <NUM> being in a falling phase. Since rotation directions of the drive rotors are different when the drive rotors <NUM> are in the rising phase and in the falling phase, a phase difference of the two moving magnetic field curves is opposite. Therefore, whether the drive rotors <NUM> are in the rising phase or the falling phase is able to be determined according to the phase differences. Since the drive rotors <NUM> rotate uniformly, the moving magnetic field curve of the induction magnetic ring <NUM> collected by the multiple Hall sensors <NUM> is regular, a period of the moving magnetic field curve of the induction magnetic ring <NUM> is changed when the drive rotors <NUM> no longer rotate or no longer rotate uniformly, and whether rotation of the induction magnetic ring is blocked is determined by observing the period of the moving magnetic field curve.

Specifically, when the motion conditions of the drive rotors <NUM> are determined according to the phase differences and/or the periods of the different moving magnetic field curves, the drive rotors <NUM> being in the rising phase or the falling phase is determined according to the phase differences of the different moving magnetic field curves; and whether the drive rotors <NUM> rotate is determined according to the periods of the different moving magnetic field curves.

It should be noted that since rotation directions of the drive rotors are different when the drive rotors <NUM> are in the rising phase and in the falling phase, a phase difference of the two moving magnetic field curves is opposite. When the electronic expansion valve is designed, it is necessary to give whether the drive rotors are the rising phase or the falling phase when which curve precedes. Or, it is necessary to give that the positive or negative phase difference of the two moving magnetic field curves corresponds to the rising phase or the falling phase, so as to determine whether the drive rotors <NUM> are in the rising phase or the falling phase.

Since the drive rotors <NUM> rotate uniformly, the moving magnetic field curve of the induction magnetic ring <NUM> collected by the multiple Hall sensors <NUM> is regular, periods of the moving magnetic field curves of the drive rotors <NUM> are changed when the drive rotors <NUM> no longer rotate or no longer rotate uniformly, and whether rotation of the induction magnetic ring is blocked is determined by observing the period of the moving magnetic field curve. When the electronic expansion valve is designed, the period of the moving magnetic field curve of the induction magnetic ring <NUM> during normal motion is collected in advance. During working of the electronic expansion valve, if the period of the moving magnetic field curve is less than a period of the moving magnetic field curve of the induction magnetic ring <NUM> during normal motion, rotation of the electronic expansion valve is blocked.

With the two Hall sensors <NUM> as an example, the two Hall sensors <NUM> are arranged, when the motion conditions of the drive rotors <NUM> are determined according to the phase differences and/or the periods of the different moving magnetic field curves, if the phase difference of the two moving magnetic field curves is positive, the drive rotors <NUM> being in the rising phase is determined; and if the phase difference of the two moving magnetic field curves is negative, the drive rotors <NUM> being in the falling phase is determined. One Hall sensor <NUM> is marked as a first Hall sensor, the other Hall sensor <NUM> is marked as a second Hall sensor, and the phase difference is the moving magnetic field curve of the first Hall sensor minus the moving magnetic field curve of the second Hall sensor. The drive rotors <NUM> being in the rising phase is determined when the phase difference of the two moving magnetic field curves is positive, and the drive rotors <NUM> being in the falling phase is determined when the phase difference of the two moving magnetic field curves is negative. Therefore, whether the drive rotors <NUM> are in the rising phase or the falling phase may be determined according to the positive or negative phase difference of the two moving magnetic field curves.

In particular examples shown in <FIG> and <FIG>, a solid line is a moving magnetic field curve of a first Hall sensor <NUM>, and a dashed line is a moving magnetic field curve of a second Hall sensor <NUM>. As shown in <FIG>, when drive rotors <NUM> rotate in a forward direction, the solid line is ahead of the dashed line, and a phase difference is positive. As shown in <FIG>, when drive rotors <NUM> rotate in a reverse direction, the dashed line is ahead of the solid line, and a phase difference is negative.

In particular examples shown in <FIG> and <FIG>, moving magnetic field curves of Hall sensors <NUM> are square waves, a solid line is the moving magnetic field curve of a first Hall sensor <NUM>, and a dashed line is a moving magnetic field curve of a second Hall sensor <NUM>. As shown in <FIG>, when drive rotors <NUM> rotate in a forward direction, the solid line is ahead of the dashed line, and a phase difference is positive. As shown in <FIG>, when drive rotors <NUM> rotate in a reverse direction, the dashed line is ahead of the solid line, and a phase difference is negative.

Of course, the at least two Hall sensors <NUM> are arranged, the phase difference of the moving magnetic field curves of the two Hall sensors <NUM> are only referred, and the phase difference of the moving magnetic field curves of the at least two Hall sensors <NUM> are also referred.

As shown in <FIG> and <FIG>, an included angle X between projections of centers of induction portions of the two adjacent Hall sensors <NUM> and a center of the induction magnetic ring <NUM> in the height direction of the accommodating cavity <NUM> and the number n of magnetic poles of the induction magnetic ring <NUM> satisfy: <MAT> a unit of the included angle X being a degree; and N being an integer.

The included angle between the two adjacent Hall sensors <NUM> is determined according to the number n of magnetic poles of the induction magnetic ring, and moreover, how many Hall sensors <NUM> are placed may be also computed. Such an arrangement is accurately determine the motion condition of the induction magnetic ring by means of the moving magnetic field curve.

As shown in <FIG> and <FIG>, a distance L between the centers of the induction portions of the two adjacent Hall sensors <NUM>, the number n of the magnetic poles of the induction magnetic ring <NUM> and a projection distance r from the centers of the multiple Hall sensors <NUM> to the center of the induction magnetic ring <NUM> in the height direction of the accommodating cavity <NUM> satisfy: <MAT>.

Under the condition that the number n of the magnetic poles of the induction magnetic ring <NUM> is determined, there is a linear function between the distance L and the projection distance r.

The distance L between the centers of the induction portions of the two adjacent Hall sensors <NUM> is related to the number n of the magnetic poles of the induction magnetic ring <NUM> and the projection distance r from the centers of the multiple Hall sensors <NUM> to the center of the induction magnetic ring <NUM> in the height direction of the accommodating cavity <NUM>, and the distance L between the centers of the induction portions of the designed two adjacent Hall sensors <NUM> is different in the different number n of the magnetic poles of the induction magnetic ring <NUM>.

The electronic expansion valve further includes a coil assembly, a valve body assembly and a sleeve, where the coil assembly is arranged in the frame body <NUM> and located on an outer side of the drive rotors <NUM>, the valve body assembly includes a valve seat and a valve needle, the valve needle moving along with the drive rotors <NUM> to open and close a valve port on the valve seat, the sleeve is arranged in the accommodating cavity <NUM>, is fixedly connected to the valve body assembly, and is provided with a cavity, and the drive rotors <NUM> move in the sleeve.

Claim 1:
An electronic expansion valve, comprising:
a frame body (<NUM>), the frame body (<NUM>) being provided with an accommodating cavity (<NUM>) and a mounting cavity (<NUM>);
an induction magnetic ring (<NUM>), the induction magnetic ring (<NUM>) being movably arranged in the accommodating cavity (<NUM>) in a height direction of the accommodating cavity (<NUM>), and the mounting cavity (<NUM>) being at least located on a circumferential outer side of an active area of the accommodating cavity (<NUM>) in which the induction magnetic ring (<NUM>) is located; and
a Hall sensor (<NUM>), there are multiple Hall sensors (<NUM>), at least two Hall sensors (<NUM>) of the multiple Hall sensors (<NUM>) being located in the mounting cavity (<NUM>) and being arranged around a circumferential side of the accommodating cavity (<NUM>), the at least two Hall sensors (<NUM>) of the multiple Hall sensors (<NUM>) being located at the same height, and the induction magnetic ring (<NUM>) being always in a detection range of the multiple Hall sensors (<NUM>).