JP3509261B2 - Small electric motor - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a small motor provided with a Hall sensor and a Hall sensor holder which accommodates the Hall sensor and protects and positions the Hall sensor. 2. Description of the Related Art An induction motor or a brushless DC motor is used as a small motor mounted on an air conditioner or the like. Further, in the induction motor, a Hall sensor is used for detecting the rotation speed, and in the brushless DC motor, a Hall sensor is used for detecting the rotor position and the rotation speed. A conventional brushless DC motor of a small motor will be described with reference to FIGS. FIG. 3 is a sectional view of a conventional brushless DC motor. FIG. 4 is an enlarged side sectional view of a conventional hall sensor mounting portion. In FIG. 3, a brushless DC motor 2
Is assembled with a stator 3, a rotor 4, a bearing bracket 5, and a bearing 6. The stator 3 includes an insulator 7
A core 9 on which a winding 8 is wound via a substrate and a substrate 10 mounted on the insulator 7 are molded by a premix 14. The substrate 10 has a brushless D
Electronic components for driving and controlling the C motor 2 and the Hall sensor 11 and the like are mounted on the three equal parts. Further, a Hall sensor holder 12 is provided to prevent the Hall sensor 11 from being broken by injection pressure during molding and to position the Hall sensor 11. [0005] A cylindrical magnet 13 is provided on the outer periphery of the rotor 4 so as to face the inner periphery of the core 9. The magnet 13 extends in the axial direction longer than the thickness of the core 9. The Hall sensor 11 detects the magnetism of the extended portion of the magnet 13, and can calculate the position and the number of rotations of the rotor. . In FIG. 4, a Hall sensor holder 1 is shown.
2 is provided between the core 9 and the substrate 10;
The protrusion 12 of the Hall sensor holder 12 is
b is inserted and attached to the substrate 10. The hall sensor 11 is housed in the housing hole 12a of the hall sensor holder 12, and is protected from external pressure. Further, the hall sensor 11 is connected to the storage hole 12.
a, the lead pin 11b protruding from the bottom surface of the Hall sensor main body 11a is passed through the through hole 12c of the Hall sensor holder 12, connected to the substrate 10, and soldered. Further, the bottom surface of the hall sensor body 11a and the bottom surface of the storage hole 12a are brought into close contact with each other and stored, so that the position of the hall sensor 11 is fixed, and the magnetism generated by the magnet 13 is reliably and accurately. Can be detected. However, when the Hall sensor is housed in a conventional Hall sensor holder and the positioning and protection of the Hall sensor are performed, the temperature rise during the operation of the brushless DC motor or premixing is performed. The Hall sensor holder expands due to heat generated when the stator is formed. That is, the bottom surface of the Hall sensor body, the substrate, and the Hall sensor holder between them are closely attached to determine the position of the Hall sensor. Therefore, when the Hall sensor holder expands, stress is applied to the portion where the lead pin is soldered to the substrate by pressing the Hall sensor body and the substrate, and cracks may occur in the solder. Therefore, according to the present invention, there is provided a small electric motor including a hall sensor and a hall sensor holder which houses the hall sensor and protects and positions the hall sensor. Hallse
Hall sensor holder made of resin
At the bottom of the hole in the
Forming a plurality of through holes for passing the signal line,
Receiving the bottom of the wire with the plurality of protrusions, and
Through the through hole, and without bending the signal line.
It engaged with the plate, to provide a compact electric motor, characterized in that to fix the end of the signal line by only soldering. The position of the Hall sensor is fixed by positioning the bottom of the Hall sensor body on a buffer or a protrusion provided on the bottom surface of the storage hole of the Hall sensor holder to fix the position of the Hall sensor. . In addition, by easily deforming the cushioning material or the protrusion, even if the protrusion of the Hall sensor holder expands due to heat, the force for pressing the Hall sensor main body is reduced, and the lead pin of the Hall sensor is soldered to the substrate. Does not generate solder cracks in the parts. An embodiment of the present invention will be described with reference to FIGS. FIG. 1 is an enlarged side sectional view of a hall sensor mounting portion according to the present invention. FIG. 2 is an enlarged front cross-sectional view of the hall sensor mounting portion in the present invention. 1 and 2, the Hall sensor holder 1 is provided between a substrate 10 and a core 9 and attached to the substrate 10 as in the prior art. The hall sensor 11 is housed in the housing hole 1a of the hall sensor holder 1 and is protected from external pressure. When the Hall sensor 11 is stored in the storage hole 1a, the Hall sensor body 1
The lead pin 11b protruding from the bottom surface of the hole 1a passes through the through hole 1b of the Hall sensor holder 1 and is soldered to the substrate 10. Also, at the bottom of the storage hole 1a, 1
One or a plurality of protrusions 1c is the Hall sensor holder 1.
It is integrally molded. The projection 1c can be easily deformed when an external pressure is applied. For example, the tip of the projection 1c is sharpened at an acute angle. Then, the protrusion 1c and the bottom surface of the hall sensor main body 11a are stored in contact with each other, whereby the position of the hall sensor is fixed, and the magnetism generated by the magnet 13 can be reliably and accurately detected. In this embodiment, the projection integrally formed with the Hall sensor holder has been described. Instead of the projection, a cushioning material such as rubber may be provided on the bottom surface of the Hall sensor body and the bottom surface of the storage hole of the Hall sensor holder. A similar effect can be obtained by inserting the same into the. With the above configuration, even when the Hall sensor holder expands due to a temperature rise during operation of the brushless DC motor or heat generated when the stator is formed by premixing, the storage hole of the storage hole is not affected. Due to the deformation of the cushioning material or the projection provided on the bottom surface, the force for pressing the Hall sensor main body is reduced, and it is possible to prevent the occurrence of solder cracks in the soldering portion between the lead pin of the Hall sensor and the substrate. According to the present invention, even if the Hall sensor holder expands due to heat, the stress of the Hall sensor and the Hall sensor mounting portion of the substrate can be reduced. [0016]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an enlarged side sectional view of a hall sensor mounting portion according to the present invention. FIG. 2 is an enlarged front sectional view of a hall sensor mounting portion according to the present invention. FIG. 3 is a cross-sectional view of a conventional brushless DC motor. FIG. 4 is an enlarged sectional side view of a conventional hall sensor mounting portion. [Description of Signs] 1, 12 Hall sensor holder 2 Brushless DC motor 3 Stator 4 Rotor 5 Bearing bracket 6 Bearing 7 Insulator 8 Winding 9 Core 10 Substrate 11 Hall sensor 12 Hall sensor holder 13 Magnet 14 Premix

Claims (1)

(1) A small motor having a hall sensor and a hall sensor holder for housing the hall sensor and protecting and positioning the hall sensor. Hallsen formed by
A plurality of protrusions and hole sensors
Forming a plurality of through holes for passing the signal line of the sir , receiving the bottom of the Hall sensor with the plurality of protrusions,
And passing the signal line through the through hole,
Without bending it, and engage the end of this signal line with half.
A small motor that is fixed by padding.