JPH0674074U - Motor device - Google Patents

Abstract

(57) [Summary] (Correction) [Purpose] To provide a motor device capable of fixing a magnet and a rotating shaft without using an adhesive and detecting an accurate rotation speed of the motor. A magnet for detecting the rotation speed of a rotation shaft of a motor and a Hall IC arranged on the housing side of the motor so as to face the rotation shaft and for detecting the rotation speed of the motor are provided. The magnet is a rotation shaft of the motor. 36. A ring-shaped magnet body in which a through hole 58 having an inner diameter slightly larger than the outer diameter is formed. And a collar 60 that is attached integrally to the collar 60.
Contacts the inner peripheral surface of the through hole 58 on the outer peripheral surface of the through hole 58,
The collar 60 has a plurality of protrusions 84 for centering the magnet body 56 with respect to the rotary shaft 36, and the collar 60 is fixed by pressure to the outer circumference of the rotary shaft 36 of the motor.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a motor device, and more particularly to a motor device capable of detecting the number of rotations of the motor.

[0002]

[Prior art]

 Conventionally, as this type of motor device, for example, one shown in FIG. 5 has been known.

This motor device is used for a power seat device of an automobile, and a rotating shaft 12 is provided in a motor housing 10 so as to be capable of forward and reverse rotation. A worm gear 18 that meshes with a worm wheel (not shown) is provided on a part of the rotating shaft 12.

A magnet 14 for detecting the rotation speed of the motor is fixed to a part of the rotary shaft 12 near the worm gear 18. On the housing 10 side corresponding to the magnet 14, a Hall IC 16 is provided as a sensor for detecting the rotation speed of the motor by the rotation of the magnet 14. Then, the magnet 14 and the Hall IC 16 are adapted to detect the seat position of the power seat device which moves with the rotation of the motor.

[0005]

[Problems to be solved by the device]

 However, in the above-mentioned conventional motor device, since the magnet 14 is fixed to the rotating shaft 12 of the motor by adhesion, a drying process of the adhesive is required, and it takes time to manufacture the motor. There was a problem that it would end up.

Also, in order to reduce the time, a drying oven may be used, but in this case, not only a drying oven is required, but also other components are not dried while the adhesive is being dried using the drying oven. However, there is a problem that other parts may be adversely affected by the heat.

Further, as described above, when the magnet 14 is fixed to the rotating shaft 12 by adhesion, if the magnet 14 is located near the worm gear 18, the adhesive will flow into the worm gear 18 side and will be changed later. There was a problem that it would cause noise and malfunction.

It is also conceivable to form the center through hole of the magnet 14 small and press-fit and fix the rotating shaft 12 to it, but this causes a problem that the magnet 14 is easily broken and the yield is reduced. there were.

Further, in order to avoid the cracking of the magnet 14 as described above, if the central through hole of the magnet 14 is formed large, as shown in FIG. 6, when the magnet 14 is mounted on the rotary shaft 12, There is a problem that the magnet 14 tends to be eccentric with respect to the rotating shaft 12. Thus, when the magnet 14 is mounted in an eccentric state, as shown in FIG. 6, the difference between the minimum distance L1 from the magnet 14 to the hole IC16 and the maximum distance L2 increases depending on the rotational position. Therefore, the detection pulse of the Hall IC is output as shown by B in the figure in the case of the minimum distance L1, but in the case of the maximum distance L2, there is a so-called pulse missing state as shown by A in the figure. As a result, the Hall IC 16 cannot accurately read the change in the magnetic flux of the magnet 14, and the ECU (computer) cannot accurately detect the rotation speed of the motor.

The present invention has been made in view of such conventional problems, and an object thereof is to fix a magnet and a rotary shaft without using an adhesive and to eliminate a step of drying the adhesive. In addition, there is no need to use a drying oven, so there is no influence of heat on other parts, and there is no noise or malfunction due to the flow of adhesive. An object of the present invention is to provide a motor device capable of detecting

[0011]

[Means for Solving the Problems]

 In order to achieve the above-mentioned object, the invention of claim 1 is: a motor rotation speed detection magnet mounted and fixed to a part of a rotation shaft of a motor; In a motor device having a sensor for detecting the rotation speed of a motor by rotating the magnet, the magnet is a ring-shaped magnet body having a through hole with an inner diameter slightly larger than the outer diameter of the rotation shaft of the motor. A collar that is inserted into the through hole of the magnet body so that a predetermined gap is formed between the magnet body and the inner peripheral surface of the magnet body, and is integrally mounted. Has a plurality of protrusions on its outer peripheral surface that abut the inner peripheral surface of the through hole and position the center of the magnet main body with respect to the rotary shaft. It is characterized by being crimped and fixed.

In the invention of claim 2, the collar has a portion forming the plurality of protrusions and a portion pressed against the rotating shaft, and an inner diameter of the portion forming the protrusion is It is characterized in that it is formed to be larger than the inner diameter of the portion pressed against the rotating shaft.

[0013]

[Action]

 In the motor device configured as described above, the collar is integrally mounted in the through hole formed in the magnet body, and the magnet is crimped and fixed to the outer circumference of the rotation shaft of the motor through this collar, so that the magnet is not damaged during press fitting. It becomes possible to press-fit and fix it on the outer circumference of the rotating shaft.

In particular, since a gap is formed between the outer peripheral surface of the collar and the inner peripheral surface of the magnet, it is possible to reliably prevent the stress transmission to the magnet when the magnet is press-fitted and prevent the magnet from cracking. Is possible.

As described above, since the magnet and the rotary shaft can be fixed without using the adhesive, the step of drying the adhesive is unnecessary, and the drying furnace is also unnecessary. Therefore, it is possible to prevent the other components from being affected by the heat, and further to prevent abnormal noise and malfunction due to the flow of the adhesive.

Further, when the magnet is attached to the collar, a plurality of protrusions formed on the outer peripheral surface of the collar come into contact with the inner peripheral surface of the through hole of the magnet to position the center of the magnet. Despite the gap in the magnet, the magnet is mounted without eccentricity, and it is possible to detect the accurate rotation speed of the motor by keeping the distance from the sensor constant.

Further, in the motor device according to the second aspect, the inner diameter of the portion where the protrusion of the collar is formed is made larger than the inner diameter of the portion where the collar is pressed against the rotating shaft, so that the collar is connected to the magnet of the magnet through the protrusion. Despite contact with the inner peripheral surface of the through hole, it is possible to more reliably prevent stress transmission to the magnet during press fitting of the magnet and prevent cracking of the magnet.

[0018]

【Example】

 Next, preferred embodiments of the present invention will be described in detail with reference to the drawings.

1 to 3 show a preferred embodiment in which the present invention is applied to a motor for a seat slide in a power seat device.

As shown in FIG. 2, in the motor of this embodiment, a rotor 32 integrally formed with a rotary shaft 36, a magnet 34 for forming a field, a worm wheel (see FIG. (Not shown), a thrust bearing portion 40, a rotation speed detecting magnet 38, and a Hall IC 39 as a rotation speed detecting sensor are arranged.

The motor housing 30 is formed by combining a metal yoke portion 42 and a resin housing portion 44.

The metal yoke portion 42 is formed of a material such as an iron plate, and the resin housing portion 44 is formed of a synthetic resin material such as PET.

The rotor 32 is rotatably arranged in the metal yoke portion 42. The magnet 34 is attached to the inner wall surface of the metal yoke portion 42 around the rotor 32 to form a field.

A commutator 46 is disposed at the end of the rotor 32, and a brush 48 that comes into contact with the commutator 46 is provided around the metal yoke 42 side of the commutator 46. The rotary shaft 36 penetrates the rotor 32 and the commutator 46, and is arranged across the metal yoke portion 42 and the resin housing portion 44.

The rotating shaft 36 is rotatably supported by the bearing metal 50 in the metal yoke portion 42 and the resin housing portion 44, and the movement in the radial direction is restricted.

Further, a worm gear 52 is formed in a part of the rotary shaft 36 on the resin housing portion 44 side, and the worm wheel (not shown) meshes with the worm gear 52 so that the worm gear 52 can move in the axial direction of the rotary shaft 36. Rotational force is transmitted in the orthogonal direction. Therefore, when the rotating shaft 36 rotates forward and backward, a load in the thrust direction is applied to the rotating shaft 36 via the worm gear 52 that meshes with the worm wheel.

Therefore, the resin flat plate 54 provided on the end portion of the rotary shaft 36 is pressed against and supported by the end portion on the metal yoke portion 42 side, and the end portion on the resin housing portion 44 side is set on the side end portion of the resin housing portion 44. The thrust bearing portion 40 provided is pressed and supported to receive the load in the thrust direction.

In the present invention, the magnet 38 for detecting the rotational speed and the Hall IC 39 as a sensor for detecting the rotational position detect the rotational speed of the motor to detect the position of the sheet. As shown in FIG. 1, the magnet 38 is provided at a position adjacent to the worm gear 52 of the rotary shaft 36, and the Hall IC 39 is provided at a position facing the magnet 38 on the resin housing portion 44 side. There is.

As shown in FIGS. 3 and 4, the magnet 38 includes a ring-shaped magnet body 56 and a collar 60 that is integrally attached to the magnet body 56. It is press-fitted and fixed to the outer circumference of 36.

The ring-shaped magnet main body 56 is made of ferrite or the like, and its outer diameter is set to be smaller than the inner diameter of the bearing metal 50 a located in the center and the through hole 58 formed in the center. The inner diameter of the motor is set to be slightly larger than the outer diameter of the rotary shaft 36 of the motor. Thus, by making the outer diameter of the magnet 38 smaller than the inner diameter of the bearing metal 50a located in the center, the rotor 32 can be assembled to the housing after the magnet 38 is assembled to the rotating shaft 36. Therefore, it is easy to assemble the magnet 38 to the motor, and automatic assembly by a robot or the like is possible. Further, by making the inner diameter of the through hole 58 larger than the outer diameter of the rotary shaft 36, damage during mounting on the rotary shaft 36 is prevented.

The collar 60 is made of non-magnetic material such as brass, aluminum, synthetic resin, etc., and has a cylindrical portion 78 inserted into the through hole 58 of the magnet body 56 and one side surface of the magnet body 56. The side portion 80 covering the above is bent and formed integrally. Then, the cylindrical portion 78 is inserted into the through hole 58, and a gap 82 is formed between the outer peripheral surface of the cylindrical portion 78 and the inner peripheral surface of the through hole 58 of the magnet body 56. The side surface is fixed to the side portion 80 of the collar 60 with an adhesive.

When the magnet 38 is press-fitted and fixed to the rotary shaft 36, even if a deforming force is applied to the collar 60, the deforming stress is absorbed by the existence of the void 82, and the deforming stress is transmitted to the magnet body 56. Is prevented, and damage to the magnet body 56 is prevented. Therefore, it is possible to omit the drying process and the drying oven compared with the case of fixing by adhesion, and eliminate the influence of heat during drying on other parts and the abnormal noise and malfunction due to the flow of adhesive. It becomes possible.

Further, the cylindrical portion 78 of the collar 60 is formed with four protrusions 84, which are in contact with the inner peripheral surface of the through hole 58 of the magnet main body 56, on the outer peripheral surface on one side in the axial direction at intervals of 90 degrees in the peripheral direction. The center position of the magnet main body 56 is determined with respect to the cylindrical portion 78 of the collar 60, so that the magnet main body 56 is centered with respect to the rotary shaft 36 of the motor. Therefore, despite the presence of the gap 82 between the cylindrical portion 78 of the collar 60 and the inner peripheral surface of the through hole 58 of the magnet main body 56, the magnet main body 56 can be reliably centered and rotated. By keeping the distance between the outer peripheral surface of the magnet main body 56 and the Hall IC 39 constant during rotation of the shaft 36, so-called pulse breakage can be prevented from occurring, and the number of rotations of the motor can be accurately detected.

Further, the cylindrical portion 78 of the collar 60 has a pressure contact portion 88 formed on the other side of the protrusion forming portion 86 with the inner diameter L3 of the protrusion forming portion 86 on the one side in the axial direction to the rotating shaft of the motor. The inner diameter L4 is larger than the inner diameter L4. Therefore, even if the protrusion 84 formed on the protrusion forming portion 86 of the tubular portion 78 contacts the inner peripheral surface of the through hole 58 of the magnet body 56, the inner peripheral surface of the protrusion forming portion 86 contacts the outer peripheral surface of the rotating shaft 36. Instead, only the press contact portion 88 comes into contact with the outer peripheral surface of the rotating shaft 36. As a result, even if the protrusion 84 for positioning the center of the magnet main body 56 is formed on the cylindrical portion 78, the stress transmission to the magnet main body 56 at the time of press-fitting the magnet 38 to the rotary shaft 36 is prevented, and the magnet is prevented. It is possible to reliably prevent damage to the main body 56. Further, when the magnet 38 is press-fitted to the rotating shaft 36, the projection forming portion 86 is inserted from the projection forming portion 86 side of the cylindrical portion 78 having an inner diameter larger than that of the press contact portion 88 so that the projection forming portion 86 is located on the press contact portion 88 side. Since it acts as an introduction guide part to the rotary shaft 36, it becomes easy to press-fit the rotary shaft 36.

Next, the attachment state of the magnet 38 to the rotating shaft 36 of the motor will be described.

First, the tubular portion 78 of the collar 60 is inserted into the through hole 58 of the ring-shaped magnet body 38, and the side portion 80 of the collar 60 is bonded to the side surface of the magnet body 56.

When the tubular portion 78 is inserted, even if the void 82 is formed between the outer circumferential surface of the tubular portion 78 and the inner circumferential surface of the magnet body 56, the projection 84 formed on the tubular portion 78 has the through hole 58. By contacting the inner peripheral surface, the magnet main body 56 is accurately attached to the center position without being eccentric with respect to the tubular portion 78.

Further, in the cylindrical portion 78, the pressure contact portion 88 side having a smaller inner diameter than the protrusion formation portion 86 side is inserted into the through hole 58 first, so that the outer peripheral surface of the pressure contact portion 88 is inserted when the through hole is inserted. It can be easily inserted as a guide.

Next, the collar 60 is press-fitted and fixed to the rotary shaft 36 of the motor.

In this case, the cylindrical portion 78 having an inner diameter larger than that of the pressure contact portion 88 is inserted from the protrusion forming portion 86 side, and this protrusion forming portion 86 acts as an introduction guide portion to the pressure contact portion 88 side. It can be easily press-fitted into the rotary shaft 36. With such press-fitting and fixing, it is possible to omit the drying process and the drying oven as compared with the case of fixing by adhesion, and moreover, the influence of heat during drying on other parts and the adhesive It is possible to eliminate abnormal noise and malfunction due to the flow.

Further, at the time of press fitting, the protrusion 84 contacts the inner peripheral surface of the through hole 58 of the magnet main body 56 on the outer peripheral surface side, but the inner peripheral surface contacts the outer peripheral surface of the rotary shaft 36. In addition, the inner peripheral surface of the pressure contact portion 88 is in pressure contact with the outer peripheral surface of the rotating shaft 36, but the outer peripheral surface is not in contact with the inner peripheral surface of the through hole 58. Therefore, the stress at the time of press-fitting into the rotary shaft 36 is not directly transmitted to the magnet body 56, and the magnet body 56 can be reliably prevented from being damaged.

Further, the magnet main body 56 is positioned at the center position of the tubular portion 78 by the projection 84 formed on the tubular portion 78 of the collar 60, and the tubular portion 78 of the collar 60 is pressed against the rotating shaft 36 at the pressing portion 88. By doing so, the center position of the rotary shaft 36 is determined, and therefore, the center positioning of the magnet body 56 with respect to the rotary shaft 36 is automatically performed by the pressure contact of the collar 60.

By accurately centering the magnet body 56 in this way, the distance between the magnet body 56 and the Hall IC 39 is kept constant during rotation of the rotary shaft 36, and so-called pulse breakage is prevented. This makes it possible to accurately detect the number of rotations of the motor.

The present invention is not limited to the above-described embodiment, and various modifications can be made within the scope of the present invention.

For example, in the above-described embodiment, the case where the motor shaft supporting device according to the present invention is applied to the motor for seat slide in the power seat device has been described as an example, but the present invention is not limited to this. It can be applied to other applications, for example, various motors such as a seat lifter motor and a reclining motor.

Further, in the above-described embodiment, the collar 60 is composed of the cylindrical portion 78 and the side portion 80 formed on one side thereof, but the present invention is not limited to this example, and the side portion may not exist. Alternatively, not only one side but also both sides may be formed.

Further, although the case where the four protrusions 84 are formed on the tubular portion 78 of the collar 60 has been described, the present invention is not limited to this example, and the number of protrusions may be three or five or more.

Further, although ferrite is used as the material of the magnet main body 56 in the above-mentioned embodiment, the present invention is not limited to this example, and by using a high performance material such as rare earth, even if the magnet main body 56 becomes small. It is also possible to secure a sufficient effective magnetic flux.

Further, in the above embodiment, the adhesive 60 is used as the fixing means for the collar 60, but the collar 60 may be formed of synthetic resin and integrally formed.

[0050]

[Effect of device]

 As described above, in the motor device of the present invention, the magnet is integrally attached to the through hole formed in the magnet body, and the magnet is crimped and fixed to the outer circumference of the rotation shaft of the motor through the collar. It can be press-fitted and fixed to the outer circumference of the rotary shaft without damage during press-fitting.

In particular, since a gap is formed between the outer peripheral surface of the collar and the inner peripheral surface of the magnet, it is possible to reliably prevent the stress transmission to the magnet when the magnet is press-fitted and prevent the magnet from cracking. You can

Therefore, since the magnet and the rotary shaft can be fixed without using the adhesive, the step of drying the adhesive is unnecessary, and the drying furnace is also unnecessary. Therefore, the heat does not affect other parts, and further, it is possible to prevent the generation of abnormal noise or malfunction due to the flow of the adhesive.

When the magnet is attached to the collar, a plurality of protrusions formed on the outer peripheral surface of the collar come into contact with the inner peripheral surface of the through hole of the magnet to position the center of the magnet. Despite the gap in the magnet, the magnet is installed without eccentricity, and the distance from the sensor can be kept constant to accurately detect the rotation speed of the motor.

Furthermore, in the motor device according to the second aspect, the inner diameter of the portion forming the protrusion of the collar is made larger than the inner diameter of the portion pressed against the rotating shaft, so that the collar penetrates the magnet through the protrusion. Despite contact with the inner peripheral surface of the hole, it is possible to reliably prevent stress transmission to the magnet during press fitting of the magnet and prevent cracking of the magnet.

[Brief description of drawings]

FIG. 1 is an enlarged cross-sectional view of a main part of a motor device according to an embodiment of the present invention.

2 is an overall cross-sectional view of the motor device shown in FIG.

FIG. 3 is a radial cross-sectional view of a magnet.

FIG. 4 is a vertical cross-sectional view of the magnet taken along the line IV-IV in FIG.

FIG. 5 is an enlarged cross-sectional view of a main part of a conventional motor device.

FIG. 6 is an explanatory diagram showing a state in which a conventional magnet detects a rotation speed of a motor.

[Explanation of symbols]

 30 Housing 36 Rotating Shaft 38 Magnet 56 Magnet Main Body 58 Through Hole 60 Collar 78 Cylindrical Part 80 Side Part 82 Gap 84 Projection 86 Projection Forming Site 88 Pressing Site

Claims (2)

[Scope of utility model registration request] 1. A magnet for detecting the number of rotations of a motor, which is attached and fixed to a part of a rotation shaft of the motor, and a magnet, which is arranged on the housing side of the motor so as to face the magnet. In the motor device having a sensor for detecting, the magnet is a ring-shaped magnet body having a through hole having an inner diameter slightly larger than the outer diameter of the rotating shaft of the motor, and a magnet in the through hole of the magnet body. A collar which is inserted so as to form a predetermined gap with the inner peripheral surface and is integrally mounted, wherein the collar is provided on the outer peripheral surface of the through hole, and the inner peripheral surface of the through hole. And a plurality of protrusions for centering the magnet body with respect to the rotating shaft, the collar being crimped and fixed to the outer periphery of the rotating shaft of the motor. The other apparatus. 2. The rotating collar according to claim 1, wherein the collar has a portion that forms the plurality of protrusions and a portion that is pressed against the rotating shaft. A motor device, wherein the motor device is formed to have a diameter larger than the inner diameter of the portion pressed against.