JP2003032988A - Brushless motor, fixing structure of sensor magnet and magnetizing method of sensor magnet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a brushless motor wherein phase error between a permanent magnet of a rotor and a magnetic pole of a sensor magnet fit which is generated during assembling process is made as small as possible, and a structure which is easy to assemble is obtained. SOLUTION: A gear part 20, constituted of plural teeth which as a tooth surface of an involute curve, is formed on an output peripheral surface in the vicinity of one end portion of a rotating shaft 3. An engaging gear part 21, constituted of plural teeth which has a tooth surface of the involute curve and engages with the gear part 20, is formed on an inner wall of an insertion hole, into which the rotating shaft 3 of the sensor magnet 7A is inserted. The sensor magnet 7A and the rotating shaft 3 are fixed mutually in the peripheral direction of the rotating shaft 3 by engagement of the gear part 20 and the engaging gear part 21. Movement to the end of the rotating shaft 3 is obstructed, by fitting a push nut 24 in the rotating shaft 3.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a brushless motor, and more particularly to a brushless motor that simplifies assembly work and improves electrical performance.

[0002]

2. Description of the Related Art So-called brushless motors are for household use,
Although it is used for various purposes in various devices for industrial use, for example, JP-A-10-201210 proposes a brushless motor used for driving a blower fan in a vehicle air conditioner. ing. In such a conventional brushless motor, the rotational position information of the rotor is required for driving the motor. Therefore, in the vicinity of one end of the rotary shaft, a circumferential direction generally called a sensor magnet is used. While a magnet having magnetic poles formed alternately is attached to the magnet, a magnetic sensitive element is provided in the vicinity of the magnet. That is, since the sensor magnet is magnetized in correspondence with the magnetic pole position of the permanent magnet attached to the rotor, the magnetic pole of this sensor magnet accompanying the rotation of the rotating shaft detected by the magnetic sensitive element. The change in position corresponds to the change in the rotational position of the rotor. Then, the detection signal of the magnetically sensitive element is used for the drive control as the rotational position information of the rotor.

By the way, the magnetic pole position of the sensor magnet and the magnetic pole position of the permanent magnet of the rotor are, for example, described below during assembly so that they have a positional relationship corresponding to each other as described above. Each mounting position was determined by such a procedure. That is, first, at one end of the rotary shaft to which the sensor magnet is attached, the shape of the rotary shaft viewed from the end face side (in other words, the shape in the plane orthogonal to the axis of the rotary shaft) is approximately D-shaped. Partly cut out along the axial direction so as to form a shape (hereinafter, this cutout surface is referred to as "D-cut surface"), and a sensor magnet into which the end of this rotary shaft is inserted is formed. The bored insertion hole is also formed such that the shape of the surface orthogonal to the axial direction thereof is approximately D-shaped, like the end of the rotary shaft.

Then, for example, in the case where the armature coil of the brushless motor has three phases and the rotor has four permanent magnets corresponding thereto, the permanent magnet is first attached to the rotor. Four permanent magnets are attached with the D-cut surface at the tip of the rotating shaft as a reference. That is, the attachment position of one permanent magnet is determined in the direction orthogonal to the D-cut surface, and then the attachment positions of the remaining permanent magnets are determined at 90-degree intervals from this permanent magnet around the rotation axis. Then, the rotor is attached to the support portion provided inside the motor. On the other hand, the sensor magnet is magnetized in the circumferential direction based on the magnetic pole position in the circumferential direction of the rotor with the D cut surface formed inside the insertion hole as a reference, and then the D cut surface of the rotating shaft is formed. It is assembled by fitting it to the end.

[0005]

However, in the conventional assembling process as described above, assembling errors occur at a plurality of points, which are eliminated and accumulated in deviations. However, there is a problem that the performance of the completed motor tends to vary. That is, during the above-described series of assembly steps, first, the mounting position of the permanent magnet of the rotor is determined on the basis of the D-cut surface of the rotating shaft, and when mounting the permanent magnet, an error easily occurs in the mounting position, Due to this, a phase error in the magnetic pole position of the permanent magnet occurs. Further, even when the sensor magnet is magnetized with the D-cut surface of the sensor magnet as a reference, it is difficult to magnetize so that each magnetic pole position is formed without error. Occurs.

Furthermore, even in the step of fitting the magnetized sensor magnet to the D-cut surface of the rotary shaft, the fitting state is not as designed due to variations in the finishing accuracy of the respective members. Even at this stage, a relative phase error occurs between the permanent magnet of the rotor and the magnetic pole of the sensor magnet. As described above, in the conventional brushless motor, there is a problem that a phase error of the magnetic pole is generated at least at three large places during the assembling process, which causes a variation in performance. In addition, in the conventional structure, the D-cut surface of the rotating shaft and the D-cut of the sensor magnet are combined with the fact that it takes a relatively long time to attach the permanent magnet of the rotor and the sensor magnet when assembling them. On the other hand, since the manufacturing cost is relatively high, there is a problem that the price of the brushless motor is eventually increased.

The present invention has been made in view of the above circumstances, and is a brushless motor having a structure in which the phase error between the magnetic poles of the permanent magnet of the rotor and the sensor magnet during the assembly process is as small as possible and the assembly is easy. ,
A sensor magnet mounting structure and a method for magnetizing a sensor magnet are provided. Another object of the present invention is to provide a brushless motor and a sensor magnet mounting structure that can be easily reduced in thickness. Another object of the present invention is to provide a method for magnetizing a sensor magnet, which can simplify the work.

[0008]

In order to achieve the above object, the brushless motor according to the present invention detects a magnetic pole change due to rotation of a sensor magnet attached to one end of a rotary shaft on which a rotor is supported. However, a brushless motor configured to rotate the rotor by generating a rotating magnetic field by controlling the energization of the armature coil provided in the stator, and the brushless motor near one end of the rotating shaft. On the outer peripheral surface, a gear portion including a plurality of teeth having a tooth surface formed by a tooth profile forming curve is formed,
The sensor magnet is provided with an insertion hole into which the rotary shaft is inserted, and the inner wall of the insertion hole includes a plurality of teeth having tooth surfaces formed by a tooth profile forming curve. Is formed, and the sensor magnet has the gear part of the rotating shaft fitted to the fitting gear part, and the sensor magnet has a shaft from one end side of the rotating shaft. The movement prevention member is fitted and attached to one end of the rotary shaft.

In such a structure, unlike the prior art, when the sensor magnet is attached to the rotary shaft, it is attached to the rotary shaft without specifying the circumferential position of the sensor magnet with respect to the rotary shaft, and then attached to the sensor magnet. Since it is designed to be magnetized, in the assembly process of the brushless motor, the only place where a phase difference with the magnetic pole of the rotor occurs is theoretically the process of magnetizing the sensor magnet, and the assembly is easier than in the past. It is possible to provide a brushless motor which is easy and has a sufficiently small phase error between the magnetic poles of the rotor and the sensor magnet.

In order to achieve the above-mentioned object, the method for magnetizing a sensor magnet according to the present invention comprises:
A method for magnetizing a sensor magnet in a brushless motor according to claim 2, wherein a rotor and a stator are assembled at least, and the sensor magnet is attached to one end of a rotary shaft. In this state, a DC voltage is applied to one phase of the armature coil provided on the stator, the rotor rotates due to the application of the DC voltage to the armature coil, and then to a stable position. In the stopped state, the sensor magnet is magnetized based on the magnetic pole position of the rotor.

In such a method, it is sufficient to magnetize the sensor magnet in the circumferential direction based on the magnetic pole position of the rotor, and it is possible to magnetize more easily than before, so that the working time can be shortened. As a result, a less expensive brushless motor can be provided.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to FIGS. The members, arrangements, and the like described below do not limit the present invention and can be variously modified within the scope of the gist of the present invention. First, a configuration example of a brassless motor to which the sensor magnet mounting structure according to the present invention is applied will be described with reference to FIG. First, FIG.
It is a structural example of a brushless motor used for driving a blower fan of a vehicle air conditioner, and shows a general mounting state of a rotor 4 and sensor magnets 7A, 7B, 7C. Therefore, energization of an armature coil 11 is performed. The mounting positions of the circuit board 8 for performing control and the case member 5 that constitutes the housing 6 are schematically indicated by the chain double-dashed line, and detailed illustration is omitted. Has become.

The brushless motor according to the embodiment of the present invention has a structure having a stator 2 whose base is fixed to a motor flange 1 and a rotor 4 fixed to a rotating shaft 3 which is rotatably provided. There is. The motor flange 1 has sensor magnets 7A, 7B,
On the side where 7C is located, a case member 5 is attached by screwing or the like to form a housing 6, and one end of the rotary shaft 3 to which the sensor magnets 7A, 7B, 7C are attached faces the inside of the housing 6. The circuit board 8 is housed. The stator 2 is formed by winding a winding around an armature core 10 attached to the outer periphery of a support cylinder 9, and for example, an armature coil 11 having 6 poles is formed. The 6-pole armature coil 11 is connected to form, for example, a three-phase star connection or a delta connection, and three armature terminals provided so as to project to the lower surface side of the motor flange 1. 12a to 12c (only 12a and 12b are shown in FIG. 1). Further, the armature terminals 12a to 12c are connected via a wiring (not shown) to a control circuit (not shown) formed on the circuit board 8 provided at the position shown by the dotted line, and by this control circuit, The rotating magnetic field is generated by switching the energizing current. The support cylinder 9 as a support member is formed in a hollow cylindrical shape, and one end of the support cylinder 9 is fixed to the motor flange 1 so as to communicate with the inside of the housing 6.

Further, bearings 13a and 13b are provided inside the support cylinder 9 in the vicinity of both ends thereof, and the rotary shaft 3 is rotatably supported. Here, the bearing 13
Reference characters a and 13b are formed by using a member obtained by impregnating a sintered bond metal containing iron or copper as a main component with a lubricating oil such as spindle oil, and between the support cylinder 9 and the rotary shaft 3. It is pressed into. The rotary shaft 3 is provided so that both ends thereof project from the support cylinder 9, and a portion of the rotary shaft 3 projecting from the opposite side of the base (the side connected to the motor flange 1) of the support cylinder 9 is provided. The rotor 4 is fixed.

The rotor 4 of this embodiment includes a rotor housing 14 formed in a substantially arm shape, and the rotor housing 14
And a permanent magnet 15 provided on the inner peripheral surface of
The rotor housing 14 is fixed to the rotating shaft 3 inserted in the center of the bottom so that the bottom side of the rotor housing 14 faces upward (opposite the motor flange 1 side) and the opening side faces the motor flange 1. A thrust washer 16 and a retainer 17 inserted through the rotary shaft 3 are interposed between the inner bottom of the rotor housing 14 and the bearing 13a. Of course, the member interposed between the inner bottom portion of the rotor housing 14 and the one bearing 13a does not necessarily have to be the one described above. For example,
A so-called oil stopper, a rubber washer, and a washer may be laminated in this order from the inner bottom side of the rotor housing 14.

The permanent magnet 15 is fixed to the inner peripheral surface of the rotor housing 14 so as to face the armature core 10 at its peripheral edge, and the number of magnetic poles thereof is the six-pole armature of the stator 2 described above. It has four poles with respect to the coil 11. On the other hand, sensor magnets 7A, 7B and 7C are attached to the end of the rotary shaft 3 facing the motor flange 1 with an attachment structure as described later. In FIG. 1, the sensor magnet 7
The detailed mounting structure of A, 7B, and 7C is not shown. The sensor magnets 7A, 7B and 7C are magnetized in the circumferential direction corresponding to the magnetic pole positions in the circumferential direction of the rotor 4, and in the present embodiment, they are magnetized so that four magnetic poles are formed. It has been done. In the vicinity of the sensor magnets 7A, 7B and 7C, a magnetic sensitive element (not shown) typified by, for example, a Hall element, which detects a change in magnetic pole due to its rotation and outputs a voltage signal according to the detected magnetic pole, is roughly It is provided at an appropriate position on the circuit board 8 showing the attached state of. The detection signal of this magnetically sensitive element is used for driving a brushless motor in a control circuit (not shown) formed on the circuit board 8.

The brushless motor having the above structure is used as a so-called blower fan motor in a vehicle air-conditioning control device or the like, for example, with a fan (not shown) fixed above the rotary shaft 3 (a portion opposite to the motor flange 1). It is like this. In the brushless motor having the above-described structure, the position of the rotor 4 is detected by the magnetically sensitive element (not shown), and the circuit board 8 is energized to the armature coil 11 based on the detection result. The rotor 4 is rotated by being controlled by a control circuit (not shown).

Next, the sensor magnets 7A, 7B, 7C
A specific mounting structure of will be described with reference to FIGS. 2 to 10. First, in the case of the specific mounting structure of the sensor magnets 7A, 7B, 7C described below, in any case, the sensor magnets 7A, 7B
Unlike the conventional method, B and 7C do not need to be magnetized in advance,
It is premised that it is preferable to magnetize by a magnetizing method to be described later after mounting. First, the first configuration example will be described with reference to FIGS. 2 to 4. In this first configuration example, first, the gear portion 20 is formed with an appropriate length in the axial direction on the outer peripheral surface near the end of the rotary shaft 3 to which the sensor magnet 7A is attached (see FIG. 3), and A fitting gear portion 21 that fits with the gear portion 20 is also formed on the inner wall of the insertion hole 22a of 7A (see FIG. 4). That is, the gear unit 20
Is formed by forming a plurality of teeth 20a having a tooth surface formed by an involute curve as a tooth profile forming curve. On the other hand, in the sensor magnet 7A according to the embodiment of the present invention, first, the external shape will be described. The overall shape is roughly disk-shaped, and the rotating shaft 3 is inserted in the central portion. Insertion hole 22
a is bored, and a fitting gear portion 21 is formed therein as described later. Further, the peripheral portion of the insertion hole 22a of the sensor magnet 7A according to the embodiment of the present invention is annular and relatively flat on either side in the axial direction of the insertion hole 22a (the front-back surface direction in FIG. 4). The first annular projection 23a and the second annular projection 23b are formed so as to project slightly to the left (see FIGS. 2 and 4).

The fitting gear part 21 is formed with a plurality of fitting teeth 21a having a tooth surface formed by an involute curve as a tooth profile forming curve on the inner wall surface of the insertion hole 22a of the sensor magnet 7A, This fitting tooth 21a
The teeth 20a of the rotary shaft 3 are fitted between the two (see FIGS. 2 and 4). Incidentally, the size of the involute, the number of teeth, etc., should be appropriately selected according to the size of the motor, that is, the size of the rotating shaft and the sensor magnet, etc., and need not be limited to specific conditions. Here, the specific size of the involute, the number of teeth, etc. are not specified. In this structure, the sensor magnet 7A is attached to the rotary shaft 3 by
The rotary shaft 3 is inserted into the insertion hole 22a of the sensor magnet 7A from the end portion on the side where the gear portion 20 is formed.
Located in. Then, a publicly known and well-known push nut 24 as a shaft movement preventing member is fitted from the end of the rotary shaft 3, and the push nut 24 is pushed to a position where a minute gap is generated between the push magnet 24 and the sensor magnet 7A. It has been completed (see Figure 2). The push nut 24 prevents the sensor magnet 7A from falling off from one end of the rotary shaft 3. Here, the small gap between the push nut 24 and the sensor magnet 7A is, specifically,
It is about 2 mm. This is a push nut 2
This is to prevent distortion when the 4 and the sensor magnet 7A are joined to each other without such a so-called play, due to thermal expansion of each. The gear portion 20 of the rotating shaft 3 as described above can be manufactured by so-called extrusion molding or the like in which a rod-shaped member is pushed into a mold in which a portion such as the fitting gear portion 21 of the sensor magnet 7A is formed. It is possible. The fitting gear portion 21 of the sensor magnet 7A can be manufactured by lathe processing or the like. In the example above,
Although the example using the involute curve as the tooth profile forming curve has been shown, it is needless to say that it is not limited to this curve and may be another tooth profile forming curve for forming the tooth profile of the gear, for example, The curve may be a cycloid curve or the like. Further, in order to prevent the sensor magnet 7A from falling off from one end of the rotating shaft 3, the push nut 24 is used as an axial movement preventing member that prevents the sensor magnet 7A from moving toward one end of the rotating shaft 3. It is needless to say that it is not limited, and other members such as a snap ring may be used as long as they have the same function.

Next, a second structural example will be described with reference to FIGS. The same components as those of the first configuration example shown in FIGS. 2 to 4 are designated by the same reference numerals, detailed description thereof will be omitted, and different points will be mainly described below. In this second configuration example, one end of the rotary shaft 3 inserted into the sensor magnet 7B is formed in a cylindrical shape, while the inner wall of the insertion hole 22b of the sensor magnet 7B is a cylinder. It is formed into a shape (see FIG. 6). In addition, in the embodiment of the present invention, with respect to the diameter d1 of the rotary shaft 3, the insertion hole 22b
Has a diameter d2 set to be slightly larger (d1 <d2). This is for facilitating the movement of the sensor magnet 7B in the axial direction in order to finely adjust the position of the sensor magnet 7B with respect to the magnetic sensitive element (not shown). Then, on the first annular protrusion 23a of the sensor magnet 7B, a locking protrusion 27 formed in an extremely small columnar shape is provided at an appropriate position in the circumferential direction so as to protrude in a direction parallel to the axis of the insertion hole 22b. Has been done. On the other hand, when the push nut 25 as the shaft movement preventing member is fitted into the rotating shaft 3, a portion corresponding to the above-mentioned locking protrusion 27 is bored to form a through hole 25a. However, except for this point, it is basically the same as the publicly known / known one. In addition, in the embodiment of the present invention, an example in which the shape of the locking protrusion 27 is formed in a cylindrical shape is shown.
The shape does not need to be limited to a cylindrical shape, of course, and various shapes such as a prismatic shape can be selected. In this configuration example, the locking protrusion 27 and the through hole 25a formed so that the locking protrusion 27 described above penetrates when the push nut 25 is fitted into the rotating shaft 3. The rotation inhibiting means has been realized.

In this structure, the sensor magnet 7B is attached to the rotary shaft 3 by first inserting one end of the rotary shaft 3 into the insertion hole 22b from the side opposite to the side where the locking projection 27 of the sensor magnet 7B is provided. Insert to the appropriate position. Next, in the push nut 25, the position of the locking projection 27 of the sensor magnet 7B and the through hole (not shown) formed in the push nut 25 for the locking projection 27 are arranged in the circumferential direction of the rotary shaft 3. Then, the rotary shaft 3 is fitted in from the shaft end so as to be almost in the same position, and finally the locking projection 27 of the sensor magnet 7B is pushed into the push nut 2.
The push nut 25 is pushed through a through hole (not shown) of No. 5 and is pushed to a position where a minute gap is generated between the push nut 25 and the sensor magnet 7B, thereby completing the attachment. Therefore, the sensor magnet 7B is
The push nut 25 prevents the rotary shaft 3 from falling off from one end, and reliably prevents the rotary shaft 3 from rotating in the circumferential direction. Here, the reason for providing the minute gap between the push nut 25 and the sensor magnet 7B and the degree of its size are the same as those described in the first configuration example. In addition, in the case of the first configuration example described above, the axial movement blocking member is not limited to the push nut 25 described above, and may be, for example, a snap ring. Is the same as.

Next, FIG. 8 to FIG. 1 for the third configuration example.
Description will be given with reference to 0. The same components as those in the configuration examples shown in FIGS. 2 to 7 are designated by the same reference numerals, and detailed description thereof will be omitted. Hereinafter, different points will be mainly described. In this third configuration example, the sensor magnet 7
A notch 28 is formed in the first annular protrusion 23a of C, and the notch 28 is adapted to be engaged with the engaging piece 26a of the push nut 26 as the axial movement preventing member. (See FIG. 8). That is, in this third configuration example, the rotation inhibiting means is realized by the first annular projection 2 having the cutout 28 formed therein and the locking piece 26a. The notch 28 is formed by notching a part of the first annular protrusion 23a so as to be parallel to the radial direction of the sensor magnet 7C (see FIG. 10). In other words, the first annular protrusion 23a is D-cut to form the notch 28. As a result, the planar outer shape of the sensor magnet 7C is substantially D-shaped as shown in FIG. On the other hand, the push nut 26 in the third configuration example has a planar outer shape formed in a substantially D shape similar to that of the sensor magnet 7C, and is bent at a right angle from a D-shaped straight portion. The stop piece 26a is extended (see FIGS. 8 and 9). The locking piece 26a is bent in the direction opposite to the insertion direction of the push nut 26 (see FIG. 8). In addition, the insertion direction of the push nut 26 means a direction in which the rotary shaft 3 is inserted when the push nut 26 is attached. For example, in FIG. is there.

In this structure, the sensor magnet 7C is attached to the rotary shaft 3 by first inserting the sensor magnet 7C from the side of the second annular projection 23b of the sensor magnet 7C.
One end of the rotary shaft 3 is inserted into b to an appropriate position. Next, the push nut 26 is attached to one end of the rotary shaft 3, and the position of the locking piece 26a and the first annular projection 2
The push nut 26 is fitted into the rotary shaft 3 in correspondence with the position of the notch 28 of 3a, and the engaging piece 26a of the push nut 26 is engaged with the notch 28 of the sensor magnet 7C to complete the installation. As a result, the sensor magnet 7C is prevented from coming off from one end of the rotary shaft 3 by the push nut 26, and the rotation of the rotary shaft 3 in the circumferential direction is prevented by the notch 28 and the locking piece 26a. It will be surely prevented by the engagement. In addition, in the case of the first configuration example described above, the axial movement blocking member is not limited to the push nut 26 described above, and may be, for example, a snap ring. Is the same as. Further, in order to realize the rotation inhibiting means, in the above-mentioned example, the first annular protrusion 23a is formed with the notch 28 having a D cut, but the push nut 26 If the portion and the first annular protrusion 23a are engaged with each other and the rotation of the sensor magnet 7C is prohibited,
The planar outer shape of the cutout portion 28 does not need to be limited to the substantially D shape, and various shapes can be selected.

Next, a method of magnetizing the sensor magnet suitable for the sensor magnet mounted with the above-described mounting structure will be described. Note that the sensor magnet in the following description of the magnetizing method may be any of the sensor magnets 7A, 7B, 7C in the above-described first to third configuration examples. Therefore, in the following description, Sensor magnets 7A, 7B, 7
The sensor magnet 7 is used as a general term for C. First, FIG. 11 to FIG.
This will be described with reference to FIG. 11 to 13, the structure of the brushless motor is simplified for the sake of convenience. Therefore, the structure of the sensor magnet 7 and its mounting structure on the rotary shaft 3 may be any of those shown in FIGS. 2 to 10 as described above. In FIGS. 11 to 13, the mounting structure thereof. Is not shown. First, as a premise, the rotor 4 to which the sensor magnet 7 is attached is attached to the motor flange 1. Further, although not shown in the drawing, the rotor 4 and the motor flange 1 are connected to each other as shown in FIG.
It is assumed that what is to be provided in this portion has already been arranged as shown in FIG.

Under such a premise, the motor flange 1 is fixed so that the sensor magnet 7 is on the upper side in the vertical direction, and any one of the three armature terminals 12a to 12c provided on the motor flange 1 is set. A DC power supply 32 so that a DC voltage can be applied between the two via a switch 31.
Are provided (see FIG. 11). Then, the switch 31 is changed from the open state to the closed state and the armature terminals 12a to 12c.
A DC voltage is applied between any two of them (see FIG. 12). In other words, the DC voltage is applied to any one of the three-phase armature coils 11. As a result, two of the six poles of the armature coil 11 are excited, whereby the rotor 4 rotates in a stable direction in relation to the excited two poles, and the two poles are excited. Magnetic pole and rotor 4
It will stop at a stable position where the attraction and repulsion with the magnetic poles of are balanced. In the state where the rotor 4 rotates as described above and stops at the stable position, the magnetizing means 33 is brought closer to the sensor magnet 7 from above, and the sensor magnet 7 is magnetized in the circumferential direction based on the stop position of the rotor 4. (See FIG. 13). That is, as the armature coil 11 is excited, the rotor 4 stops at the stable position determined by the relative relationship with the magnetic field generated by the armature coil 11 as described above. In this state, the magnetic pole position in the circumferential direction of the rotor 4 can be easily known because the attachment of the permanent magnet 15 in the circumferential direction is known in advance. Therefore, the sensor magnet 7 may be magnetized in the circumferential direction according to the magnetic pole position in the circumferential direction of the rotor 4 in this state, whereby the magnetic pole position of the sensor magnet 7 by the magnetically sensitive element (not shown). The detection of the change of (1) corresponds to the change of the rotational position of the rotor 4 (in other words, the change of the magnetic pole position of the rotor 4). It should be noted that the magnetizing means 33 here is not known to this magnetizing method but is publicly known / known. Here, although detailed description of the magnetizing means 33 is omitted, for example, specifically, an electromagnetic coil and
It is composed of a drive circuit for controlling the energization amount, energization direction, etc. to the electromagnetic coil, and is designed to bring the magnetizing coil close to the sensor magnet 7 for magnetizing.

In the magnetizing method according to the procedure described above, the phase error between the magnetic pole position of the sensor magnet 7 and the magnetic pole position of the permanent magnet 15 of the rotor 4 is basically caused by the magnetic flux distribution of the rotor 4. There is only one step of magnetizing the sensor magnet 7 with reference to. On the other hand, in the conventional case, a phase error occurs in at least three steps as mentioned in the section of the problem to be solved by the invention.
Therefore, in the magnetizing method according to the above-described embodiment of the present invention, the phase error is sufficiently smaller than that of the conventional method, and the brushless motor has a very small variation in electrical characteristics.

Next, the second magnetizing method will be described with reference to FIGS. 14 to 16. 14 to 1
6 is also the sensor magnet 7 as in FIGS.
The mounting structure and the like are shown in a simplified form. First, the motor flange 1 is fixed so that the sensor magnet 7 is on the upper side in the vertical direction (see FIG. 14). Next, at the outer circumference of the rotor 4, 2
The same magnetic poles of the two permanent magnets 34a and 34b are arranged with an angle difference of 180 degrees (see FIG. 15). In FIG. 15, N
Although the example in which the poles are arranged is shown, it goes without saying that the S poles may be arranged. This permanent magnet 34
Due to the arrangement of a and 34b, the rotor 4 is
The magnetic poles a and 34b and the magnetic pole of the rotor 4 are rotated and stopped in the stable position direction in which the attraction and repulsion force are balanced.

When the rotor 4 is stopped at the stable position, the magnetizing means 33 is brought close to the sensor magnet 7 from above to magnetize the sensor magnet 7 in the circumferential direction based on the stop position of the rotor 4. (See FIG. 16). Here, the magnetization of the sensor magnet 7 based on the stop position of the rotor 4 has the same meaning and content as described in the first magnetization method above, and therefore detailed description thereof will not be repeated here. I will.

It should be noted that any of the above-mentioned magnetizing methods is suitable when the above-described mounting structure of the sensor magnets 7A, 7B, 7C is used, and this magnetizing method itself is shown in FIGS. It is not applicable unless it has the sensor magnet mounting structure shown in FIG. 10, and can be applied to magnetize the sensor magnet as long as it conforms to the sensor magnet mounting structure shown in FIGS. 1 to 10. Is. Further, in the above-described magnetizing method, it has been described on the assumption that the magnetic pole position of the permanent magnet 15 of the rotor 4 and the magnetic pole position of the sensor magnet 7 correspond to each other. Even in the case where a deviation of a predetermined angle is provided between the position of the magnetic pole of the permanent magnet 15 of the rotor 4 and the position of the magnetic pole of the sensor magnet 7, as is generally done from the viewpoint of efficiency and the like. However, it suffices to perform the magnetization in the above-described procedure in consideration of the deviation, and even in this case, the magnetization method in the embodiment of the present invention can be applied without contradiction.

[0030]

As described above, according to the attachment structure of the brushless motor and the sensor magnet according to the present invention, the conventional D-cut surface of the rotating shaft and the D-cut surface inside the insertion hole of the sensor magnet are used. Instead, it has a mounting structure that allows the sensor magnet to be fixed at any position in the circumferential direction of the rotating shaft, making it easier to assemble than before and shortening the working time. Combined with the structure that does not require forming the D-cut surface of the rotary shaft and sensor magnet, which required a high processing cost in the past, it is inexpensive and ensures secure attachment of the rotary shaft and the sensor magnet. The effect is that it can be done. Further, unlike the prior art, it is not necessary to join the so-called D-cut surface formed on the rotary shaft to the sensor magnet, so that the thickness of the sensor magnet in the axial direction of the rotary shaft cannot be reduced in order to secure the bonded surface sufficiently. Therefore, it is possible to avoid the conventional inconvenience, and therefore, it is possible to reduce the thickness of the brushless motor. Further, unlike the conventional case, the permanent magnet to be attached to the rotor does not need to be attached with the so-called D-cut surface as a reference, so that there is no need for highly accurate dimensional control in the attaching process as in the past, and the work is simplified. The price can be increased. Further, according to the method of magnetizing the sensor magnet according to the present invention, unlike the conventional method, the sensor magnet may be magnetized corresponding to the arrangement of the permanent magnets without measuring the magnetic flux distribution of the permanent magnets of the rotor. Therefore, the work can be simplified as compared with the conventional one, and in combination with the mounting structure of the sensor magnet, the phase error of the magnetic pole position can be made smaller than the conventional one. It is a thing.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view showing a schematic configuration of a brushless motor to which a sensor magnet mounting structure according to an embodiment of the present invention is applied.

FIG. 2 is a front view showing a first configuration example of a sensor magnet mounting structure according to the embodiment of the present invention.

3 is a front view of a rotary shaft in the sensor magnet mounting structure shown in FIG. 2. FIG.

4 is a plan view of the sensor magnet in the sensor magnet mounting structure shown in FIG. 2. FIG.

FIG. 5 is a front view showing a second configuration example of the sensor magnet mounting structure according to the embodiment of the present invention.

6 is a plan view of the sensor magnet in the sensor magnet mounting structure shown in FIG. 5. FIG.

7 is a front view of the sensor magnet in the sensor magnet mounting structure shown in FIG. 5. FIG.

FIG. 8 is a front view showing a third configuration example of the sensor magnet mounting structure according to the embodiment of the present invention.

9 is a plan view of a push nut in the sensor magnet mounting structure shown in FIG. 8. FIG.

10 is a plan view of the sensor magnet in the sensor magnet mounting structure shown in FIG. 8. FIG.

FIG. 11 is a schematic diagram schematically showing a connection state of a DC power supply or the like in the first example of the method of magnetizing the sensor magnet according to the embodiment of the present invention.

FIG. 12 is a schematic diagram schematically showing an energized state of the armature coil in the first example of the method for magnetizing the sensor magnet according to the embodiment of the present invention.

FIG. 13 is a schematic diagram schematically showing a magnetized state of the sensor magnet in the first method example of the method of magnetizing the sensor magnet according to the embodiment of the present invention.

FIG. 14 is a schematic diagram schematically showing a fixed state of the brushless motor when the magnetizing method in the second method example of the magnetizing method of the sensor magnet according to the embodiment of the present invention is carried out.

FIG. 15 is a schematic diagram schematically showing a fixed state of the rotor with an external magnetic field in the second example of the method for magnetizing the sensor magnet according to the embodiment of the present invention.

FIG. 16 is a schematic diagram schematically showing a magnetized state of the sensor magnet in the second example of the method of magnetizing the sensor magnet according to the embodiment of the present invention.

[Explanation of symbols]

1 ... Motor flange 3 ... Rotary axis 7A ... Sensor magnet (first configuration example) 7B ... Sensor magnet (second configuration example) 7C ... Sensor magnet (third configuration example) 20 ... Gear part 21 ... Fitting gear section 27 ... Locking protrusion 28 ... Notch 33 ... Magnetizing means

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Tomoyuki Mizuguchi             39, Higashihara, Chiyo-ji, Konan-cho, Osato-gun, Saitama Prefecture               Zexel Valeo Climate Co., Ltd.             In control F-term (reference) 5H019 AA10 BB02 BB05 BB15 BB19                       BB22 CC04 DD01                 5H611 AA01 BB01 BB07 PP05 QQ03                       RR02 UA01                 5H622 CA05 CA10 PP01 QB01

Claims (10)

[Claims] 1. A rotating magnetic field is detected by detecting a change in magnetic pole due to rotation of a sensor magnet attached to one end of a rotating shaft on which a rotor is supported and controlling energization to an armature coil provided on a stator. A brushless motor configured to generate and rotate the rotor, wherein the outer peripheral surface near one end of the rotating shaft includes a plurality of teeth having a tooth surface formed by a tooth profile forming curve. While the gear part is formed, the sensor magnet is provided with an insertion hole into which the rotary shaft is inserted, and the inner wall of the insertion hole has a plurality of tooth surfaces formed by a tooth profile curve. The toothed portion of the rotary shaft is formed with a fitting gear portion to which the gear portion is fitted, and the sensor magnet has the gear portion of the rotating shaft fitted to the fitting gear portion, and Brushless motor, characterized in that a shaft movement hampering member is fitted from one end side of the rotating shaft formed by attached to one end of the rotary shaft. 2. A rotating magnetic field is detected by detecting a change in magnetic pole due to rotation of a sensor magnet attached to one end of a rotating shaft on which a rotor is supported and controlling energization to an armature coil provided on a stator. A brushless motor configured to generate and rotate the rotor, wherein the sensor magnet has an insertion hole into which one end of the rotation shaft is inserted, and the rotation hole is inserted into the rotation hole. One end of the shaft is inserted, and a shaft movement blocking member is fitted from one end of the rotary shaft and attached to the one end of the rotary shaft. A brushless motor, characterized in that rotation inhibiting means for inhibiting rotation of the sensor magnet is formed between the magnet and the shaft movement preventing member. 3. The rotation prohibiting means comprises a locking projection, which is provided near one peripheral edge of the insertion hole of the sensor magnet so as to be parallel to the axial direction of the insertion hole, and the locking projection. 3. The brushless motor according to claim 2, wherein the brushless motor comprises a through hole formed in the shaft movement preventing member so as to penetrate therethrough. 4. The rotation inhibiting means is formed flat around one side of the insertion hole of the sensor magnet so that the outer shape in a plane orthogonal to the axial direction of the insertion hole is substantially D-shaped. In addition, it is configured to include a protrusion formed to project in the axial direction and a locking piece formed to the axial movement blocking member so as to engage with a linear portion of the protrusion. Item 2. The brushless motor according to item 2. 5. A structure for mounting a sensor magnet used in a brushless motor on a rotary shaft, wherein a plurality of tooth surfaces formed by a tooth profile curve are formed on an outer peripheral surface near one end of the rotary shaft. On the other hand, the sensor magnet is formed with an insertion hole into which the rotary shaft is inserted, and the inner wall of the insertion hole has a tooth formed by a tooth profile forming curve. A plurality of teeth having a surface, and a fitting gear portion to which the gear portion is fitted is formed, and the sensor magnet has the gear portion of the rotating shaft fitted to the fitting gear portion. A mounting structure for a sensor magnet, wherein a shaft movement blocking member is fitted from one end side of the rotary shaft and attached to one end part of the rotary shaft. 6. A mounting structure for a sensor magnet used in a brushless motor to a rotating shaft, wherein the sensor magnet has an insertion hole into which one end of the rotating shaft is inserted, One end of the rotary shaft is inserted into the hole, and a shaft movement blocking member is fitted from one end of the rotary shaft and attached to the one end of the rotary shaft. At the same time, the sensor magnet mounting structure is characterized in that rotation inhibiting means for inhibiting rotation of the sensor magnet is formed between the sensor magnet and the shaft movement blocking member. 7. The rotation prohibiting means includes a locking projection, which is provided near one peripheral edge of the insertion hole of the sensor magnet so as to be parallel to the axial direction of the insertion hole, and the locking projection. 7. The sensor magnet mounting structure according to claim 6, wherein the mounting structure includes a through hole formed in the shaft movement blocking member so as to penetrate therethrough. 8. The rotation prohibiting means is formed flat around one side of the insertion hole of the sensor magnet so that the outer shape in a plane orthogonal to the axial direction of the insertion hole is substantially D-shaped. In addition, it is configured to include a protrusion formed to project in the axial direction and a locking piece formed to the axial movement blocking member so as to engage with a linear portion of the protrusion. Item 6. The mounting structure for the sensor magnet according to item 6. 9. A method of magnetizing a sensor magnet in a brushless motor according to claim 1, wherein the rotor and the stator are assembled at least, and In the state where the sensor magnet is attached to one end of the rotating shaft, a DC voltage is applied to one phase of the armature coil provided on the stator, and the rotor causes the DC voltage to be applied to the armature coil. A method of magnetizing a sensor magnet, wherein the sensor magnet is magnetized based on a magnetic pole position of the rotor in a state where the sensor magnet is rotated and then stopped at a stable position. 10. A method of magnetizing a sensor magnet in a brushless motor according to claim 1, wherein the rotor and the stator are assembled at least, and In the state where the sensor magnet is attached to one end of the rotating shaft, the same magnetic pole faces the two magnetism generating means around the rotor with an angle difference of 180 degrees about the rotating shaft with the rotor sandwiched therebetween. Magnetized to the sensor magnet based on the magnetic pole position of the rotor in a state where the rotor rotates due to the arrangement of the two magnetism generating means and then stops at the stable position. A method for magnetizing a sensor magnet, comprising: