JP2011516021A - Brushless vibration motor - Google Patents

Abstract

The present invention relates to a DC brushless vibration motor, and more particularly, the present invention relates to a vibration motor capable of forming a cogging torque generating portion within the thickness of a non-magnetic body.
A vibration motor according to the present invention includes a stator, a rotor, and a case. In particular, the stator includes a main body that is a non-magnetic body and a magnetic body that is accommodated within the thickness of the main body. A bracket composed of a cogging torque generator, at least one coil fixed to the upper surface of the bracket and generating electromagnetic force so that the rotor is rotated, and the bracket without being superimposed on the coil. And a circuit board fixed directly to the upper surface.
[Selection] Figure 3

Description

  The present invention relates to a brushless vibration motor, and more particularly, the present invention relates to a vibration motor capable of forming a cogging torque generating portion within the thickness of a main body that is a non-magnetic material.

  Recently, the demand for longer life and higher reliability is increasing with increasing frequency of use of vibration modes of mobile communication terminals.

  Various vibration motors have been researched and disclosed so far to perform the vibration mode. As an example, a brushless DC (BLDC) vibration motor will be described with reference to FIGS.

  As illustrated, the brushless vibration motor includes a case 10, a bracket 20 ′, a stator 30, a rotor 40, a fixed shaft 50, and a cogging torque generator 62.

  The case 10 is configured to cover the bracket 20 ′ and the fixed shaft 50 in the form of a cap.

  The bracket 20 'is made of a non-magnetic material, and a rib 22 into which the fixed shaft 50 is inserted is formed at the center thereof.

  The stator 30 is fixed to the upper surface of the bracket 20 ′, which has a trapezoidal shape on the upper surface of the circuit board 31, one or more coils 32 that generate a predetermined electromagnetic force, and a Hall element. A control unit 33 in the form of a chip that functions as a drive IC is provided.

  In this case, the control unit 33 is configured to detect the polarity of a magnet 42, which will be described later, to generate an electrical signal, and to determine the current direction of the coil 32 according to the polarity of the magnet 42.

  The rotor 40 includes a rotor body 41 made of a resin material, a rotor yoke 44, a magnet 42 having a predetermined number of poles, a weight 43, and a metal bearing 52, and rotates by mutual magnetic action with the stator. It is provided in the inside.

  The magnet 42 is configured to interact with an electromagnetic force generated from the coil 32 to generate a force such as an attractive force and a repulsive force, and to rotate at a predetermined speed by the force.

  The metal bearing 52 is coupled to the center of the rotor yoke 44 and is sandwiched between the fixed shafts 40 to minimize frictional resistance when the rotor 40 rotates.

  The weight 43 provides an eccentric mass when the rotor 40 rotates and functions to generate a vibration force.

  The fixed shaft 50 is configured such that one end is sandwiched between the ribs 22 provided on the bracket 20 ′, the other end is fixed between the shaft grooves of the case 10, and the rotor 40 can be rotated. The slip is supported by the washer 51.

  The cogging torque generating unit 62 serves to stop the rotor 40 at a fixed position and smooth the start without a starting point at the time of starting so that a predetermined equal interval is maintained on the upper surface of the bracket 20 ′. Combined and made of soft magnetic material.

  When the magnet 42 has four poles, the cogging torque generator 62 is designed with a number (two) that maintains an equal interval of 180 °, and when the magnet 42 has six poles, the cogging torque generator 62 is designed by the number (three) which maintains the equal interval of 120 °.

  Further, as described above, each cogging torque generator 62 that maintains a predetermined equal interval is configured with a protrusion 61 ′ for enhancing the strength of the cogging torque, while its central portion is wound. The installation position is set so as to deviate from the central portion of the coil 32 by a predetermined angle.

  However, the conventional brushless vibration motor is provided with a bracket 20 'that is a non-magnetic material and a cogging torque generating unit 62 that is a soft magnetic material (or a ferromagnetic material) as separate components, which are laminated by welding or an adhesive. Must. Therefore, there are problems that the number of parts is increased, so that it is difficult to reduce the thickness and the assembly process is complicated.

  In addition, considering that the circuit board 31 is expensive, the part price is high due to its size, and since it is in the form of a thin and flexible film, it can be easily bent during handling in the motor assembly process. There was an inconvenient problem.

  In addition, there is a problem in that the process is complicated because the coil 32 is structurally bonded and fixed to the circuit board 31 and is again bonded and fixed to the upper surface of the bracket 20 '. .

  The present invention has been devised to solve the above-described problems, and an object of the present invention is to provide a vibration motor capable of forming a cogging torque generating portion within the thickness of the main body which is a non-magnetic material. It is in.

  Another object of the present invention is to fix the coil to the bracket so as not to overlap the circuit board, so that the material cost is reduced by reducing the size of the circuit board, and the process is simplified to fix the coil directly to the bracket. An object of the present invention is to provide a vibration motor capable of increasing the thickness of the coil by the thickness of the substrate and generating a higher rotational torque and thus improving the rotational vibration force.

  In order to solve the technical problems as described above, a vibration motor according to the present invention includes a stator, a rotor, and a case. In particular, the stator includes a main body that is a non-magnetic material, and a thickness of the main body. A bracket composed of a cogging torque generating unit that is a magnetic material housed therein, at least one coil that is fixed to the upper surface of the bracket and generates an electromagnetic force so that the rotor is rotated, and And a circuit board that is directly fixed to the upper surface of the bracket without overlapping with the coil.

  Further, the main body is formed of austenitic stainless steel which is a non-magnetic material, and the cogging torque generator is transformed into a magnetic material by cold working a specific part of the main body to reduce the thickness. It is desirable to be formed.

  In addition, it is preferable that an opening is formed in the main body, and the cogging torque generating unit is a plurality of cogging torque intercepts coupled to the opening.

  Further, the cogging torque intercept may be linear, and the cogging torque intercept and the opening may be uneven in the coupling surface.

  The circuit board may be formed in one of a semicircular shape, a quadrangular shape, or a polygonal shape within a half of the area of the upper surface of the bracket.

  In addition, the rotor includes a disk-shaped rotor yoke having a shaft coupling portion through which a fixed shaft penetrates at the center and having a projecting portion projecting upward, a metal bearing inserted into the shaft coupling portion, and the projecting portion It is desirable that a through hole through which the portion penetrates is formed, a weight coupled to one side of the upper surface of the rotor yoke, and a magnet provided on the bottom surface of the rotor yoke.

  The protrusion of the rotor yoke may be coupled with a rivet or caulking while passing through the through hole of the weight.

  In addition, it is preferable that at least one stopper that protrudes inward and prevents the metal bearing from being detached is formed at the upper end or the lower end of the shaft coupling portion.

  In addition, it is preferable that a step portion to which the stopper is in close contact is formed at an upper end or a lower end of the metal bearing.

  According to the present invention, there is an effect that the cogging torque generating portion can be formed within the thickness of the main body which is a non-magnetic material.

  In addition, since the coil is fixed to the bracket so as not to overlap the circuit board, the material cost is reduced by reducing the size of the circuit board, and the process is simplified because the coil is directly fixed to the bracket. The thickness of the coil can be increased, and a higher rotational torque is generated, so that the rotational vibration force can be improved.

  In addition, the metal bearing can be firmly coupled to prevent the metal bearing from being detached due to a drop impact.

  Also, the weight can be easily coupled to the rotor yoke.

It is the figure which illustrated the conventional brushless vibration motor. It is sectional drawing which illustrated the conventional brushless vibration motor. It is the figure which showed the Example which concerns on this invention. It is the figure which showed the Example which concerns on this invention. It is the figure which showed the Example which concerns on this invention. FIG. 4 illustrates the rotor of the embodiment illustrated in FIG. 3. It is the figure which showed the various Example of the bracket based on this invention. It is the figure which showed the various Example of the bracket based on this invention. It is a figure showing other examples of a bracket concerning the present invention. It is the figure which showed the other Example of the bracket based on this invention. It is the figure which showed the production | generation rate of the processing organic martensite by the stainless steel type cold rolling rate.

  Hereinafter, the configuration and operation of an embodiment according to the present invention will be described with reference to the accompanying drawings.

  3 to 5, the embodiment 100 according to the present invention includes a stateer 130, a rotor 120, and a case 110.

  The case 110 has a cap shape and is configured to cover the stator 130 and the rotor 120.

  The stator 130 includes a bracket 131, a cogging torque segment 132, an insulating coating layer 133, a circuit board 134, a coil 136, and a fixed shaft 137.

  The bracket 131 is integrally formed with a rib (Rib) 138 through which the fixed shaft 137 penetrates at the center of the upper surface, and a large number of openings are formed outside the fixed shaft 137. A cogging torque segment 132 is formed at the opening. Are joined by press fitting, welding or adhesive.

  In this case, since the rib 138 is formed integrally with the main body of the bracket 131, the strength is structurally improved, and not only slimming is possible, but also cogging torque is generated smoothly.

  The bracket 131 has a main body with an opening formed of a non-magnetic material, and the cogging torque segment 132 is formed of a magnetic material.

  In this embodiment, the cogging torque intercept 132 and the two openings having the same distance from the center of the rib 138 of the bracket 131 are arranged in a line, but the extension lines are parallel to each other. Is done.

  The circuit board 134 is fixed to the upper surface of the bracket 131 so as not to overlap each of the coils 136, but the shape located inside the bracket 131 is formed in one form of a square or a polygon. . In this embodiment, it is formed in a square shape. In this case, there is an advantage that the use area of the circuit board 134 can be reduced by more than half than the existing one.

  Further, the circuit board 134 is mounted with a driving IC (Integrated Circuit) 135 in which a Hall sensor excluding the coil 136 is built in the upper surface, and a hole corresponding to the rib 138 is formed through the tip. When the substrate 134 is fixed, the position after the hole is inserted into the rib 138 is fixed. Eventually, since the coil 136 is not bonded onto the circuit board 134, the area is reduced, so that the material cost can be reduced even if a soft PCB is used, and further work can be performed if a relatively inexpensive hard PCB is used. Easier and material costs can be saved.

  The coil 136 is directly fixed to the upper surface of the bracket 131 without overlapping the circuit board 134, and at least one of the coils 136 is fixed so that an electromagnetic force can be generated so that the rotor 120 rotates. In this embodiment, a case where two are provided is illustrated.

  In this case, it is preferable that the coil 136 is first coated with an insulating paint or an adhesive on the upper surface of the bracket 131 and then fixed.

  Accordingly, the stator 130 of the vibration motor of the present embodiment is attached and fixed so that the circuit board 134 and the coil 136 are not overlapped with each other when the circuit board 134 and the coil 136 are attached to the upper surface of the bracket 131. No material cost is saved.

  That is, since the corresponding part of the circuit board 134 on which the driving IC 135 excluding the coil 136 is not subjected to thickness restrictions, a relatively low-cost thick hard PCB is used instead of an expensive thin flexible PCB. This is an economic advantage.

  Further, the process for directly bonding the coil 136 to the bracket 131 is simplified, and the height of the thickness of the circuit board 134 at the bottom of the coil 136 is removed from the laminated thickness of the existing coil and circuit board. In this case, there is a margin that can relatively increase the coil thickness of the coil 136, and a higher rotational torque is generated, so that the rotational vibration force can be improved.

  Further, since the circuit board 134 and the coil 136 are simultaneously attached to the bracket 131, there is an advantage that the process can be simplified.

  Referring to FIGS. 5 and 6, the rotor 120 according to the present embodiment includes a rotor yoke 123, a metal bearing 122 inserted into the shaft coupling portion, and a weight 124 coupled to one side of the upper surface of the rotor yoke 123. , And a magnet 121.

  The rotor yoke 123 is formed in a disc shape, and a shaft coupling portion through which the fixed shaft 137 passes is integrally formed at the center of rotation.

  The metal bearing 122 is sandwiched between the fixed shafts 137 while being firmly press-fitted into the shaft coupling portion, and minimizes frictional resistance when the rotor 120 rotates.

  In particular, it can be seen that an upper end of the shaft coupling portion is formed to protrude inwardly (in the inner diameter direction), and a stopper 123b is formed to prevent the metal bearing 122 from being detached upward due to an external impact. There may be various methods for forming the stopper 123b. In this embodiment, the stopper 123b is formed by pressing a predetermined portion of the round portion with a press in a state where the round portion is formed at the upper end of the shaft coupling portion. can do.

  In addition, a step 122a is formed at the upper end of the metal bearing 122 corresponding to the stopper 123b.

  Further, the shaft coupling portion is formed to have a sufficient height so that the inner peripheral surface thereof covers the entire outer peripheral surface of the metal bearing 122. If formed in this way, the contact area between the metal bearing 122 and the shaft coupling portion is increased, so that the metal bearing 122 can be more firmly coupled and fixed.

  Further, the rotor yoke 123 and the shaft coupling portion are integrally formed, but it can be seen that the rotor yoke 123 is connected to the upper end of the shaft coupling portion and has a step on the lower side. The reason for forming in this way is to provide a coupling space for the weight 124. That is, since the weight 124 can be provided within the thickness of the shaft coupling portion, the thickness can be reduced and the coupling strength can be improved.

  It can be seen that the rotor yoke 123 and the weight 124 are formed with rivet holes 123a and 124a at corresponding positions, respectively. In this embodiment, the weights 124 can be coupled very easily by riveting after aligning the rivet holes 123a and 124a.

  7, 8, 9 and 10 show various embodiments of the bracket.

  Referring to FIG. 7, according to an embodiment of the present invention, a rib through which a fixed shaft passes is integrally formed, and a body 131 having an opening 131 a and a press-fit connection to the opening 131 a of the body 131. And a cogging torque intercept 132a.

  The opening 131a and the cogging torque segment 132a are each formed of three lines, and the extension lines of the cogging torque segments 132a are arranged to form a triangle.

  The main body 131 is made of a non-magnetic material, and the cogging torque intercept 132a is made of a magnetic material.

  In particular, it can be seen that the cogging torque intercept 132a and the opening 131a are formed in a concave-convex shape with respect to each other. That is, a protrusion is formed on the edge of the cogging torque segment 132a, and a groove is formed in the opening 131a of the main body 131 corresponding to the shape and size of the protrusion.

  With such a configuration, the coupling strength between the cogging torque intercept 132a and the opening 131a is improved. Therefore, it is possible to prevent separation even at the time of external impact such as dropping. In addition, the magnetic flux density becomes higher than when no uneven surface is formed on the cogging torque intercept 132a, and the cogging torque is improved.

  Referring to FIG. 8, each of the opening 131b and the cogging torque segment 132b has four lines, and the extension lines of the cogging torque segments 132b are arranged to form a quadrangle.

  Referring to FIGS. 9 and 10, the main body 131, which is a nonmagnetic material, is formed of austenitic stainless steel, and the cogging torque generator 131 c cold-processes a specific portion of the main body 131 to reduce the thickness. As a result, it is transformed into a magnetic material.

  On the other hand, austenitic stainless steel is a nonmagnetic material having a permeability of 2 or less, although there are differences depending on grades. However, cold working partially transforms metastable austenite into processed organic martensite and becomes magnetized. It is known that the processed organic martensite phase is generated as much as austenite becomes unstable, and when the austenitic stainless steel is deformed by external stress, it increases according to the amount of deformation, and the magnetic permeability is also high. Become.

  FIG. 11 is a view showing the production rate of organic martensite by steel type according to the cold rolling rate. In the case of SUS304 (18Cr-8Ni—Fe alloy) which is a typical austenitic stainless steel, the thickness is reduced by cold rolling. It can be seen that the generation rate of processed organic martensite increases according to the amount of decrease, and the permeability increases with this.

  Referring to FIG. 10, the present embodiment utilizes the characteristics of such austenitic stainless steel. The main body 131 is formed of austenitic stainless steel, and a specific portion of the main body 131 is cold forged. To form a cogging torque generating portion 131c.

  As described above, the cogging torque generating portion 131c is formed in such a manner that a specific portion of the main body 131 is pressed and cold deformation occurs due to compression, tension, or the like.

  In this case, it is desirable that the pressing process is performed at a temperature below room temperature and the thickness is reduced by 30% or more. The cogging torque generator 131c preferably has a magnetic permeability of 10 to 1,000.

Thus, in this embodiment, the magnetic part and the non-magnetic part can be integrally formed as the same material.

Claims (10)

In a vibration motor including a stateer, a rotor, and a case,
The stateer is
A bracket composed of a main body that is a non-magnetic material, and a cogging torque generator that is a magnetic material housed within the thickness of the main body,
At least one coil fixed to the upper surface of the bracket and generating an electromagnetic force so that the rotor is rotated;
And a circuit board that is directly fixed to the upper surface of the bracket without overlapping with the coil. The main body is made of austenitic stainless steel which is a non-magnetic material, and the cogging torque generating portion is formed by being transformed into a magnetic material by cold working a specific part of the main body to reduce the thickness. The vibration motor according to claim 1, wherein: The vibration motor according to claim 1, wherein an opening is formed in the main body, and the cogging torque generator is a plurality of cogging torque segments coupled to the opening. The vibration motor according to claim 3, wherein the cogging torque intercept has a linear shape. 5. The vibration motor according to claim 4, wherein the cogging torque intercept and the opening have a concavo-convex shape on the coupling surface. 2. The circuit board according to claim 1, wherein the circuit board is formed in one shape of a semicircle, a quadrangle, or a polygon within a half of an area of the upper surface of the bracket. The described vibration motor. The rotor is
A disc-shaped rotor yoke having a shaft coupling portion through which a fixed shaft passes in the center and provided with a projecting portion projecting upward;
A metal bearing inserted into the shaft coupling portion;
A through hole through which the protruding portion is formed, and a weight coupled to one side of the upper surface of the rotor yoke;
The vibration motor according to claim 1, further comprising a magnet provided on a bottom surface of the rotor yoke. The vibration motor according to claim 7, wherein the protrusion of the rotor yoke is rivet-coupled or caulking-coupled in a state of penetrating the through hole of the weight. The vibration motor as set forth in claim 7, wherein at least one stopper is formed at an upper end or a lower end of the shaft coupling portion so as to protrude inward and prevent the metal bearing from being detached. The vibration motor according to claim 9, wherein a step portion to which the stopper is in close contact is formed at an upper end or a lower end of the metal bearing.

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