JPS5866568A - Brushless motor - Google Patents

Abstract

PURPOSE:To efficiently enhance the hole output of a Hall element by disposing a control element which controls a drive coil of one phase at the position not affected by the influence of the drive current flowing through the drive coil of the other phase. CONSTITUTION:A control element (Hall element) 6a which controls a drive coil 5a of one phase is provided at the position not affected by the influence of the drive current flowing through a drive coil 6b of the other phase. Further, a magnetic flux passing through the Hall element 6b, i.e., a magnetic flux generated by a rotor magnet 3, and a magnetic flux generated by a drive coil 5b of one phase are added. In this manner, the hole output voltage outputted by the Hall element can be efficiently enhanced, thereby accurately improving the control of the irregular rotation.

Description

[Detailed description of the invention]

The present invention relates to a brushless motor, in which the current flowing through the drive coil (two currents) is switched at ideal timing to prevent uneven rotation of the rotor as much as possible. In a so-called Hall motor that uses a detection sensor (such as a Nihole element), the magnetic flux distribution of the rotor magnet is detected as a Hall output voltage using a pole element. In a Hall motor, the magnetic flux density distribution of the magnetic flux generated from the magnetized surface of the rotor magnet is generally detected by a Hall element.
The drive current is controlled by the magnetic flux density distribution (Hall output generated in proportion to 2).In other words, this Hall output voltage is 0 [volt] (the magnetic flux density of the rotor magnet is 0 [volt]).
Gauss]), the Hall element drives the drive coil C.
'-Turn off the current driving current or change its direction. Conventionally, in two-phase winding Hall motors, the first
The configuration was as shown in the figure. Recently, as a method to reduce rotational unevenness of the rotor, a current proportional to the Hall output voltage C detected by a Hall element is used as l! n! A method in which the drive current is passed through the ll+ coil is attracting attention. But 12. Therefore, with this method, it was impossible to reduce rotational unevenness at the conventional ball element position. The structure of the conventional Hall Tanabata and its problems will be explained in detail below. FIG. 1 shows a conventional ball motor. First, the structure of the rotor will be described. Reference numeral 2 denotes a rotor case made of a magnetic material such as an iron plate, and a cylindrical rotor magnet 3 is fixed to the inside of the rotor case 2. The number of magnetic poles of this rotor magnet 3 is 6, which is a multi-pole structure, and the inner circumferential surface is alternately magnetized with N and S poles (2 magnetized. Note that 10 is a complementary pole. 2. Structure of the stator (4 is the stator core made of laminated silicon copper plates, etc., and the drive coil 5 is connected to the outer periphery of the stator core through an insulating layer such as plastic.
a and 5b are wound, and a drive coil 5a and a drive coil 5b are wound.
and have a phase difference of 90 degrees in two electrical angles.The ball element 6 serves as a control element for controlling the drive current of the drive coils 5a and 5b.
b, 6a, V, jil+ carp/I/ 5 a,
5 b (D center 11i"-, and (center!l11
1 coils 5a and 5b are provided. The ball element 6a is used to control the driving and pushing current of the drive coil 5a, and is connected to the stator core 4 around which the drive coil 5b is wound.
Similarly, the ball element 6b of the drive coil 5b that controls the drive current is formed between the stator core 4 around which the drive coil 5a is wound and the rotor magnet 3. These drive coils 5a, 5b and the Hall element fia
, 5b means the drive circuit 9 as 7r:'1- in FIG.
a, 9b. Next, when the rotor is rotating, the pole output 'voltage wave) l'z output by the ball cable 6a and the small point C
Let me explain about two things. Figure 6142 is J(, Hall element 6a
Figure 2 (A) shows the waveform of the Hall output's tortoise pressure.
2(B) is a waveform diagram of the Hall output voltage output by the ball element 6a under the influence of only the magnetic flux generated by the I-ta magnet 3, and FIG. A waveform diagram of the Hall output voltage output by the Hall element 6a, Figure 2 (0) is the same as Figure 2 (A) and Figure 2 (B).
This is a composite waveform of the ball output voltage of the Hall element 6a shown in FIG. In addition, l
Drive circuit 9a described in II A drive current proportional to the Hall output voltage of the Hall element 6a is applied to the drive coil 5a (
It consists of two. Similarly, C2, the drive circuit 9b is configured to cause a drive current proportional to the pole output voltage of the Hall element 6b to flow through the drive coil 5bl2. Now, when the drive coil 5a and the Hall element 6a are in the positional relationship as shown in FIG. has the waveform shown by the dotted line in FIG. 2(C), which is the same as the waveform shown by H2H(A). However, when the driving current flowing through the driving coil 5al increases and affects the ball element 6a, the magnetic flux generated by the driving coil 5a and the magnetic flux generated by the rotor magnet 3 become mutually different. Since the phase difference between C2 and C2 is 90' in electrical angle, the resultant magnetic flux changes depending on the drive current (2), and the Hall element 6a actually outputs C
As shown by the solid line in Figure 2 (0), the pressure is Δ0n in two electrical angles, and the waveforms are out of phase.
The rotational position of the rotor shown in the figure is shown in FIG. 2 as indicated by the mark in the figure. As mentioned above, conventionally, the control element that controls the drive coil of one phase generates a pole output voltage under the influence of the drive current flowing through the drive coil C2 of the other phase, so that the control element actually outputs The waveform of the combined Hall output voltage is as shown by the center line in Figure 2 (0).

[The two phases are blurred. Therefore, the timing of switching between the drive current flowing through the drive coil of one phase and the drive current flowing through the drive coil C''' of the other phase is shifted, making it difficult to precisely control rotational irregularities of the rotor magnet ( 6) There was a drawback that there was no delay.The feature of the present invention is that the control element that controls the drive coil of one phase is placed in a place where it is not affected by the drive current flowing to the drive coil of the other phase. The reason is that a control element for controlling the drive coil of one phase is arranged.Next, an embodiment of the present invention will be explained based on the drawings. 4 is a rotor magnet, and 4 is a stator core around which drive coils 5a and 5b are wound.These structures are the same as the conventional structure described above, but the mounting positions of Hall elements 5a and ('ib are different. Further, to explain in detail, the Hall elements 6a and 5b are arranged at the peripheral edge position of the tip end of the stator core 4, respectively, and the drive coils 5a and 5
They are installed at positions offset from the central axis of b. In this case, installing the Hall elements 6a and 5b close to the periphery of the tip of the stator core 4 effectively improves the magnetic flux C1.
Most desirable from a usage point of view. Here, Hall element 6
A functions as a control element for controlling the drive current flowing through the drive coil 5al, and a Hall element 6b functions as a control element for controlling the drive current flowing through the drive coil 51). FIG. 4 is a waveform diagram in which the horizontal axis (two hours is taken and the vertical axis is the Hall output '[jj pressure) output by the Hall system element 6b, and FIG. 4 (A) shows the waveform generated by the rotor magnet 3. Figure 4 (B) shows the waveform of the pole output voltage in which the Hall element 6b outputs an output under the influence of only the magnetic flux, and the Hall element 6b outputs under the influence only of the magnetic flux generated by the drive coil 5b. The waveform diagram of the Hall output voltage, and □g4 figure (0) is the fourth
Figure 4 (A) and Figure 4 (B) are composite waveforms of the pole output voltage of the Hall element 6b shown in (1), and the Hall element 6b actually outputs this composite Hall output voltage. is also υ). Here, the rotor magnet 3 is rotating in the clockwise direction C-, and in FIG. It detects the N pole of the magnet 3 and outputs a positive voltage.Also, in order to rotate the rotor magnet 3 in the clockwise direction C- (2. The drive coil 5b+- is connected to the tip of the stator core 4 on the Hall element 6b side with S A drive current is applied so that a pole is generated and two N poles are generated at the tip opposite to the tip on the Hall element 6b side.The waveform of this drive current is shown in FIG. 0)
Since it is similar to the waveform of the Hall output voltage shown in , it changes with the rotation of the rotor magnet 3. The rotor 7 is in the position shown in FIG.
In the magnetic flux passing through b, the magnetic flux generated from the N pole of the rotor magnet 3 and the magnetic flux generated from the N pole of the stator core 4 are in the same radial inward direction, and these two magnetic fluxes are added and sent to the Hall system. It passes through child 6b. Note that when the rotor magnet 3 is at the position (-) shown in FIG. 3C, the Hall output voltage of the Hall element 6b is maximum. The pole output voltage generated by the magnetic flux C2 of 3 (9) and the Hall output voltage generated by the magnetic flux C2 of the drive coil 5b are in phase and added.This will be explained in more detail with reference to Figure 0. N Qp of the rotor magnet 3 is on the left side of the Hall element 6b (2), and a magnetic flux is generated as shown by the arrow.On the other hand, since the drive current flows in the direction shown in the drive coil 5b, An S pole is generated on the right side, and magnetic flux is generated as shown by the broken line.Since both magnetic fluxes are the same, these magnetic fluxes are added to the Hall system element 6b, resulting in a magnetic flux density dog C. Since the Hall output voltage output from the Hall element 6b increases by 1.H, the Hall output voltage outputted by the Hall element 6b increases by that amount.
This is actually another embodiment of the present invention that is somewhat different. In FIG. 6 is a waveform diagram in which the horizontal axis is C2 time and the vertical axis is the Hall output voltage output from the Hall cable (10) 6b, and FIG. Figure 6(B) is a waveform diagram of the ball output 'torque pressure' output by the Hall element 6b under the influence of only the magnetic flux generated by the drive coil 5b. The waveform diagram of the output Hall output'pressure, Figure 4 (0) is shown in Figure 4 (
A) and Figure 4 (B) and (1) Hall element 6 shown.
A composite waveform of the Hall output voltage of Hall element 6 b.
Reference numeral 13 actually outputs the synthesized Hall output voltage. In addition, in FIG. 5, the drive coil 5b
The rotation of the drive current flowing through is the same as in the previous embodiment. 6(A) and 6(0), when the rotor magnetic 3 is in the position shown in FIG. The torque is minimized.The Hall output voltage output by the pole system element 6b is the same as in the above embodiment, but is equal to the Hall output voltage due to the magnetic flux of the rotor magnet 3 and the drive coil 5.
The Hall output voltage due to the magnetic flux of
Since there is a phase difference of 180' in two electrical angles, Hall j
The Hall output voltage of b or actual output 1 is determined by the following equation. l Vt ,'1. ' = 1. Vm 1
．． -1. Vc l However, Vt kf is the ball output voltage actually output by the Hall cable 6b, the Hall output voltage output by the pole cable 6b under the influence of only the magnetic flux of the Vm-th orotor magnet 3, and Vc is the drive coil. 5
This is the Hall output voltage output by the Hall element 6b under the influence of only the magnetic flux b. [The waveform shown by the solid line in FIG. 6(c) is the waveform of the Hall output 'city pressure actually output by the ball element 6b, and the waveform shown by the dotted line is
This is the formation of a pole output 'torque force' in which the ball element 6b is influenced only by the magnetic flux of the rotor magnet 3. This will be explained in more detail in the next C2. ] In Figure 1ζ2, N of the left side C of the hall element 6b
When the pole is located, the magnetic flux shown by the solid line is generated (8). On the right side of the ball element 6b, a driving current is passed by the driving coil 5b so as to generate an N pole, and the magnetic flux shown by the broken line is generated. ing. In this way, magnetic fluxes rotating in opposite directions pass through the Hall element 6b, and if the magnetic flux of the rotor magnet 3 is larger than the magnetic flux of the drive coil 5b, the magnetic flux of the rotor magnet 3 becomes the magnetic flux of the drive coil 5b. Therefore, the Hall output voltage actually output by the Hall element 6b is lower than the Hall output voltage output by only the magnetic flux of the rotor magnet 3. Therefore, if the drive coil 5b and the pole element 6b have a positional relationship C2 as shown in FIG. 5, when the drive current increases, the magnetic flux generated by the drive coil 5b will also become stronger in proportion to It is also possible that the Hall output voltage is reversed and malfunctions. From the above, although rotational unevenness can be controlled using the method shown in FIG. 5, the method of the embodiment described above is much more preferable. Although the case has been described in which the pole elements 5a and 5b are attached in contact with the surface of the stator core 4 in contact with the pupil portion, the present invention is not limited to this. Next, two other embodiments of the present invention will be explained.Here, we will explain the case where Hall elements 6a and ib are installed so that the position is detected by the magnetic flux generated from the end face of the rotor 1 magnet 3. In FIGS. 7 to 8 C2, a rotor case made of a yoke material is shown so that the inner circumferential surface C2 N and S poles are in contact with the outer circumferential surface of the magnetized annular rotor magnet 3. 2 is fixed. Reference numeral 7 denotes a motor support member that supports the Hall motor, and its central portion C'''-bearing 2 (2) rotatably supports the rotating shaft 1. (Second, the stator core 4 around which the drive coils 5a, 5b are wound is fixed. Also, the motor support member 7 is arranged with concentric two-hole resistors 5a, 5b facing the inner diameter of the rotor magnet 3. Here, drive coils 5a, 5b and pole series elements 6a, 5b
The positional relationship with (14) will be explained in detail below.
) The other outlines of the configuration are the same as in the previous embodiment. In FIG. 8C2, the Hall elements 6a and 5b are located at positions which have advanced in the rotational direction of the rotor magnet 3 by a phase difference of 90' in electrical angle from the center of the magnetic flux of the drive coils 5a and 5b. The two opposing end faces C'PJ
Fixed to r. Here, the Hall element 6a and the Hall element 6b have a phase difference of 7:r with respect to each other by 90' in electrical angle. It also flows into the drive coil 5a! The v1ma flow and the ball output 'acid pressure output by the Hall element 6a are in phase,
1 relay coil 5b (driving current and pole element 6b
The Hall output voltage output by the two is also in phase. Note that if the reference terminal is changed, a phase difference of J80° in electrical angle will be obtained. In this way, the Hall output voltage output from the Hall element 6a controls the drive current 7 flowing through the drive coil 5af, and the Hall output voltage output from the Hall element 6b controls the drive current flowing through the drive coil 5bl. Note that the Hall output voltage output from the Hall elements 5a and 5'b at the position □□□ shown in FIG. 8 is the value shown by mark 02 in FIG. In Fig. 8 (2), the rotor magnet 3 is rotated clockwise (O), the drive current is applied to the drive coil 5b so that the C2 S pole is generated on the Hall element 6b side, and the N pole is generated on the opposite side. be swept away. Then, a magnetic flux obtained by adding the magnetic flux generated by the rotor magnet 3 and the magnetic flux generated by the drive coil 5b, that is, a magnetic flux with increased magnetic flux density passes through the ball element 6b. This state is shown in FIG. In other words, as in the previous embodiment, c′: , Hall element 6
Since the magnetic flux passing through b is equal to the magnetic flux generated by the drive coil 5b compared to the case where only the magnetic flux generated by the rotor magnet 3 is received, as the driving current flowing through the drive coil 5'Lz increases, As a result, the Hall output voltage outputted by the ball element 6b increases, and the drive circuit 9 shown in FIG.
aC Bistable (forced by two people) If the rotation direction of the rotor magnet 3 is reversed (counterclockwise as shown in Figure 9) (2), it will malfunction as explained in Figure 5. As shown in FIG. 13, the magnetic flux of the rotor magnet 3 shown by a solid line and the magnetic flux of the drive coil 5b shown by a broken line pass through the Hall element 6b with their directions opposite to each other. , when the driving current flowing through the drive coil 5b becomes larger and the magnetic flux of the drive coil 5b becomes larger than the magnetic flux of the rotor magnet 3, the polarity of the output voltage output from the Hall element 6b is reversed, as shown in FIG. The drive circuit 9b shown in 2 malfunctions.In other words, brake torque is generated and the rotation of the rotor magnet 3 stops or the drive current is not switched smoothly and a short current is generated in the dynamic element (power transistor, etc.). ) and destroy the driven confectionery.In the above embodiment, a two-phase winding type brushless motor was explained, but the present invention is not limited to this, but a three-phase winding type brushless motor. Of course, a multi-type brushless motor or a four-phase winding type brushless motor C2 can also be used.Furthermore, in the above embodiment, two stator core type Hall motors C were used to shoulder the convex pole, but the present invention It is fully applicable to brushless motors such as slotless and (17) coreless motors.Moreover, the present invention is applicable not only to analog energization, but also to analog energization. The present invention can be applied not only to sinusoidal waveforms but also to rectangular waveforms.Finally, the present invention (see section 7 for further details on the mounting position of the pole element). When the invention is applied) 1j, the center line of the Hall element is the center line of the magnetic flux produced by the rotor magnet ('/ However, to clearly explain the center line of the magnetic flux, as shown in Figure 15 (2), the rotor magnet is shifted by three positions with a constant drive current flowing through the drive coil 5a, The torque generated at that time is the maximum C and the center line M of the rotor magnet 3.
(dashed line in the figure). If the cross-sectional shape of the drive coil 5a is fan-shaped as shown in FIG. 16 or circular as shown in FIG.
If the shape is bilaterally symmetrical, the line passing through the axis of symmetry of the drive coil 5a becomes the center line of the magnetic flux. Note that the center line of the magnetic flux here refers to the center line of the actual magnetic flux (2).If a wide spread magnetic flux is concentrated in one place, and multiple fluxes are generated from this point, it will have exactly the same effect on the rotor as the actual magnetic flux. However, the present invention provides for controlling the drive coil of one phase so that the control element that controls the drive coil of one phase is not influenced by the drive coil flowing to the drive coil of the other phase. control period
The magnetic flux passing through the Hall element, that is, the magnetic flux generated by the rotor magnet, and the magnetic flux generated by the drive coil of one phase are added to each other. Since C2 is adopted, the Hall output voltage output by the Hall element can be efficiently increased, and rotational unevenness can be controlled more effectively than in the past. Further, since the Hall element has a magnetic flux Z generated by the drive coil in the same phase as the Hall element, the armature reaction can be taken into account correctly. Furthermore, drive coil C
Since the ball output '11mo pressure outputted by the Hall element is added by j+i+7 by the amount of magnetic flux generated by the two flowing drive currents, the torque generated by the motor (V+) increases by that increase.

[Brief explanation of drawings]

Fig. 1 shows a cross section of the main part of a conventional ball motor, Fig. 2 shows a waveform diagram showing the hall output and city pressure in Fig. 1, and Fig. 3 shows an embodiment of the present invention. Figure 4 is a waveform diagram showing the ball output voltage according to Figure 1. Figure 5 is a top view showing the main part of another embodiment of the present invention. FIGS. 7 and 8 are cross-sectional views of main parts showing still other embodiments of the present invention. FIGS. 9 and 9 are similar to still other embodiments of the present invention. However, in reality (2 is a reference diagram showing a different one, Figures 10 to 13 are explanatory diagrams showing the magnetic flux distribution near the ball element, Figure 14 is a diagram showing the circuit according to the present invention (-T circuit connection diagram, 15 to 17 are explanatory diagrams showing the mounting position of the Hall element according to the present invention (1). 3. Rotor magnet, 4. Stator core 5a.
, 5b... Drive coil, 6a, 5b... Ball element, 9a, 9b... Drive circuit patent applicant Sankyo Coffin Co., Ltd. M! Factory agent Patent attorney Yu Saki (1 other person) (21) Figure 1 Figure 3 Figure 2715 NIS □ Fu□ NIS ↓ Procedural amendment (method) % formula %, title of invention Brushless motor 3, amended Relationship with the Patent Case Name of Patent Applicant (223) Yo Seiki Seisakusho Co., Ltd. (and others)
(Name) 5. February 4, 1980 with 1Q of amendment order (Date of dispatch: February 1982)
23rd of the month) 6. Subject to correction

Claims (1)

[Claims] (1) A rotor magnet with a plurality of magnetic poles magnetized in the circumferential direction (two), a stator core around which a drive coil is wound to face the rotor magnet, and a rotor core that detects the magnetic pole heat of the rotor magnet and cooperates with a drive circuit. and at least a pair of control elements for controlling the drive current flowing through the drive coils, the control element is configured to provide a control element at a location where the magnetic flux generated by the one phase drive coil and the magnetic flux generated by the rotor magnet are added. 1. A brushless motor characterized in that the brushless motor is arranged in a place where the drive coil of the other phase is not affected by the magnetic flux C2 generated by the drive coil of the other phase.