JP2002374657A - Motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a motor in which detection precision of a magnetic sensor, e.g. a Hall IC, can be enhanced. SOLUTION: In the motor 14, a board 50 fixed with Hall IC elements 40 and 42 is contained in a case 44 fixed to the outer surface of a housing 34 in the axial direction of an output gear and secured in place by means of a screw 48. When the case 44 is fixed to the outer surface of the housing 34, a protrusion 45 projecting in the axial direction of the output gear is inserted into a caulking hole 46 made on the case 44. Under the inserted state, outer circumferential part of the protrusion 45 interferes with the inner circumferential part of the caulking hole 46 in the direction orthogonal to the axial direction of the output gear. Consequently, relative displacement of the case 44 is regulated and thereby displacement of the Hall IC elements 40 and 42 is regulated resulting in the enhancement of detection precision of the Hall IC elements 40 and 42.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a motor for a power window of an automobile, for example.

[0002]

2. Description of the Related Art As a power window, there is a so-called jam protection power window for preventing foreign matter from being caught.

In this power window, the window glass rises (moves in the closing direction) and descends (moves in the opening direction) due to the forward or reverse rotation of the armature of the drive motor (motor). When a foreign object is caught between the window glass and the upper edge of the window frame during the ascent of the window glass, a lock current is generated in the drive motor. Due to the generation of the lock current, the window glass stops rising and immediately descends, thereby preventing foreign matter from being caught.

By the way, when the window glass is closed, a lock current is generated in the drive motor.

[0005] Therefore, when the window glass is closed, it is necessary to complete the closing without performing the anti-jamming operation even if a lock current is generated.

Therefore, a motor output shaft of the armature of the drive motor is provided with a plurality of pole magnets having different poles in the rotation direction, and a Hall IC is mounted on the fixed side of the drive motor corresponding to the magnet. With the rotation of the armature, a pulse is sent from the Hall IC to the ECU (or CPU).
Emitted to

According to the ECU, the pulse signal is counted up with the rotation of the armature in the ascending direction of the window glass.
Conversely, the count is down-counted with the rotation of the armature in the window glass downward direction, and the position of the window glass is detected by the pulse count number.

When a lock current is generated when the window glass is raised, the anti-jamming operation is performed by the generation of the lock current while the pulse count does not reach the preset pulse count n, and the pulse count is reduced. The count number is
After reaching the pulse count number n, the pinch prevention operation is not performed even if the lock current is generated. That is,
After the pulse count number n, a dead zone in which the closing operation of the window glass can be normally performed without performing the anti-jamming operation.

[0009]

By the way, the Hall IC
Is determined by the relative positional relationship with the magnet, and if the positional accuracy is poor, the reliability of the detection result naturally becomes low.

Here, the Hall IC is usually provided in the housing of the drive motor. The work of assembling the Hall IC in a narrow and limited space such as in a housing is complicated, and it is difficult to improve the positional accuracy of the Hall IC.

An object of the present invention is to provide a motor capable of improving the detection accuracy of a magnetic sensor such as a Hall IC in consideration of the above fact.

[0012]

According to a first aspect of the present invention, there is provided an electric motor in which an armature having a rotating shaft in which a worm is coaxially and integrally provided and a helical gear meshing with the worm are coaxially and integrally provided. An output shaft that outputs a rotational force to the outside of the helical gear, a magnet that is coaxially and integrally provided with the armature, and has a plurality of poles in which different poles are alternately arranged in the rotation direction of the armature, A magnetic sensor that is supported by the substrate in a state facing the magnet and emits a number of pulses according to the rotation angle of the magnet accompanying the rotation of the armature, and accommodates at least a part of the substrate and the substrate A case for holding the output shaft, the output shaft having a width in the axial direction sufficiently smaller than a width in a direction orthogonal to the axial direction, and a generally flat shape as a whole. A housing in which at least a part of the armature including the worm, the helical gear, and the magnet are rotatably housed therein, and the case is mounted on an outer surface from the axial direction of the output shaft. A fixing portion for connecting and fixing the case in the assembled state to the housing, and interfering with the case assembled on the outer surface of the housing from a direction orthogonal to the axial direction of the output shaft. Further, a regulating portion for regulating movement of the case in all directions orthogonal to the axial direction of the output shaft is formed on the outer surface.

In the electric motor having the above configuration, when the armature rotates, the rotation is transmitted to the output shaft via the worm and the helical gear, and the motor rotates.

When the armature rotates in this manner, the magnet provided coaxially and integrally with the armature rotates. When the magnet rotates, a pulse corresponding to the rotation angle of the magnet is emitted from a magnetic sensor arranged to face the magnet. Therefore,
By counting this pulse, the rotation speed of the armature,
Consequently, the amount of rotation of the output shaft is detected.

On the other hand, a part of the armature including the worm, the helical gear, and the magnet are housed inside the housing. Here, the housing is formed such that the width of the output shaft in the axial direction is sufficiently shorter than the width in the direction orthogonal to the output shaft, and is generally thin and substantially flat. On the outer surface of the housing, a case holding the substrate provided with the magnetic sensor is assembled from the axial direction of the output shaft,
In this assembled state, the case is connected and fixed to the outer surface of the housing by the fixing portion.

Here, if the case tries to move in the direction orthogonal to the axial direction of the output shaft with the case assembled on the outer surface of the housing, the restricting portion of the housing interferes with the case and the output shaft The movement of the case in all directions perpendicular to the rotation direction (that is, all directions in the rotational radius direction of the output shaft) is restricted. Thereby, positioning of the case with respect to the housing, that is, positioning of the case before or after the case is fixed by the fixing portion can be easily performed, and all directions orthogonal to the axial direction of the output shaft can be performed. , The positional accuracy of the magnetic sensor with respect to the position can be secured. Thereby, the detection accuracy of rotation detection by the above-described magnetic sensor can be improved.

According to a second aspect of the present invention, in the electric motor according to the first aspect, the electric motor further comprises a plurality of the fixing portions, and the other of the fixing portions corresponds to one of the fixing portions in the axial direction of the armature. , And also in the direction of rotation of the armature.

In the electric motor having the above configuration, the case is connected and fixed to the housing by the plurality of fixing portions.

Here, one of the plurality of fixing portions is displaced with respect to one in both the rotational direction and the axial direction of the armature. For this reason, even when vibrations in various directions occur when the electric motor operates, relative displacement of the case with respect to the housing is prevented or suppressed.

Thus, even when the above-described vibration occurs, the relative movement of the magnetic sensor with respect to the magnet is prevented or suppressed, and the rotation detection accuracy of the magnetic sensor can be improved.

According to a third aspect of the present invention, in the electric motor according to the second aspect, the length of the armature from one of the plurality of fixing portions to another fixing portion is along a rotation radius direction of the armature. The diameter of the rotating shaft of the armature is equal to or larger than the diameter of the rotating shaft of the armature.

In the motor having the upper configuration, the armature rotation radial component of the length from one fixed portion to the other fixed portion of the plurality of fixed portions is equal to or larger than the diameter of the rotating shaft of the armature. (In other words, when viewing a plurality of fixing portions along the rotation axis direction of the armature, the linear distance from one fixing portion to another fixing portion is longer than the diameter of the rotation shaft of the armature.) . For this reason, the case is more firmly fixed to the housing against the vibration of the armature in the rotational radius direction.

According to a fourth aspect of the present invention, in the motor according to the second aspect, the rotating shaft of the armature is located between the plurality of fixing portions.

In the motor having the upper configuration, the rotating shaft of the armature is positioned between the plurality of fixed portions, in other words, the case is fixed so that the rotating shaft of the armature is sandwiched between the plurality of fixed portions. For this reason, the case is more firmly fixed to the housing against vibrations generated when the electric motor is operated, and the rotation can be more reliably detected by the magnetic sensor over a long period of time.

[0025]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of an electric motor according to the present invention applied to a jam protection power window of an automobile will be described with reference to FIGS.

As shown in FIG. 2, in the jam protection power window 10, a DC motor 14 is provided in a vehicle door 12. The DC motor 14 is connected to a drum 16 that is driven to rotate by this.
, Both ends of the wire 18 are spirally wound. A carrier plate 20 is fixed to an intermediate portion of the wire 18, and the forward / backward rotation of the drum 16 causes the carrier plate 20 to move up and down the guide rails 22, thereby raising the window glass 24 attached to the carrier plate 20 (door). (Moving in the closing direction) and descending (moving in the door opening direction).

In the electric motor 14, as shown in FIG. 1, an intermediate portion of the motor output shaft 28 of the rotor (armature) 26
A worm 30 is formed, and a helical gear 32 meshes with the worm 30, and these are housed in a housing 34 (FIG. 3) constituting a fixed portion of the electric motor. The helical gear 32 is provided coaxially with an output gear 36 as an output shaft, which is referred to in the claims, and protrudes out of the housing 34. The drum 16 is engaged with the output gear 36 and connected thereto. The drum rotates forward (rotation in the direction of arrow A) and reverse (rotation in the direction of arrow B) due to rotation (rotation in the direction of arrow A) and reverse rotation (rotation in the direction of arrow B).

Here, as shown in FIG. 3, the housing 34 is formed such that the width of the output gear 36 in the axial direction is sufficiently smaller than the width in the direction perpendicular to the axial direction, and is generally formed in a substantially flat shape. Have been.

At the base end of the motor output shaft 28, a magnet 38 is provided annularly on the outer periphery thereof. Magnet 38
Has different poles alternately arranged in the rotation direction of the armature 26,
Multiple poles. In the present embodiment, the number of poles is two.

At the base end of the motor output shaft 28, a magnet 38 is provided annularly on the outer periphery thereof. Magnet 38
Are a plurality of poles in which different poles are arranged in the rotation direction of the armature 26. In the present embodiment, two Hall ICs constituting a magnetic sensor are provided outside the housing 34 in the radial direction of the motor output shaft 28 corresponding to the magnet 38 having two poles (first hole). IC40, 2nd hall IC42). As shown in FIG.
0 and 42 are incorporated in a substrate 50, and the substrate 50 is further incorporated in a case 44.

As shown in FIGS. 4, 7 and 8,
The case 44 is attached to the outer surface of the housing 34 in the axial direction of the output shaft 36, and one end of the case 44 is
A screw 48 is screwed into the female screw portion 47 of the wall.

The case 44 has a pair of caulking holes 46 as a regulating portion and a fixing portion. As shown in FIG. 4, these caulking holes 46 are formed on both sides of the armature 26 along the rotating direction of the armature 26 through a main body part (that is, a part containing the substrate 50) substantially constituting the case 44. ing.

As can be seen from FIG. 4, the interval between the caulking holes 46 is set to be larger than the outer diameter (diameter) of the magnet 38 provided on the outer periphery of the rotating shaft of the armature 26. In these caulking holes 46, projections 45 as restriction portions and fixing portions projecting from the housing 34 penetrate.

Each of the projections 45 protrudes in the axial direction of the output gear 36, and in a state where the projection 45 penetrates the caulking hole 46,
The outer peripheral portion of each projection 45 interferes with the inner peripheral portion of the caulking hole 46 in a direction orthogonal to the projecting direction of each projection 45, that is, in a direction orthogonal to the axial direction of the output gear 36. Accordingly, in the above penetrating state, the movement of the case 44 in the direction orthogonal to the axial direction of the output gear 36 (case 4).
4 relative to the housing 34).

Each of the protrusions 45 has its tip portion deformed to have a larger outer diameter than the caulking hole 46 by heat caulking, and is prevented from coming off from the caulking hole 46. Thereby, the case 44 is fixed to the housing 34.

Here, as shown in FIGS. 7 and 8,
One of these protrusions 45 is provided apart from the other in the left and right directions in FIGS. 7 and 8 (that is, the other protrusion 45 is spaced apart from the other by a predetermined distance around the rotation axis of the armature 26). Spaced apart). FIG.
8 and the projection 45 located on the left side of the drawing is located above the projection 45 located on the right side of the drawing (that is, the projection 45 located on the left side of the drawing is armatured with respect to the projection 45 located on the right side of the drawing). 26 is displaced along the rotation axis direction).

It goes without saying that the same applies to the caulking hole 46 through which these projections 45 pass.
7 and 8 are provided at right and left sides of FIGS. 7 and 8 with respect to the other caulking hole 46, and the caulking hole 46 is located on the right side of the paper surface. The protrusion 45 is located above the swaging hole 46 in the drawing.

Further, as described above, the interval between the caulking holes 46 is set to be larger than the outer diameter (diameter) of the magnet 38 provided on the outer periphery of the rotating shaft of the armature 26. The swaged hole 4 in the swaged state
The case 44 including the part where the magnet 6 is formed is a magnet 3
8, and the rotation axis of the armature 26 is located between the caulking holes 46.

On the other hand, as shown in FIG.
The reference numerals 40 and 42 are provided on the surface of the substrate 50 incorporated in the case 44 on the side opposite to the surface facing the magnet 38 and the armature 26, that is, the connection between the Hall ICs 40 and 42 and the magnet 38 and the armature 26. The substrate 50 is interposed between them.

As shown in FIG. 4, the first Hall IC 40 is positioned at an angular interval θ in the reverse direction of the armature 26 with respect to the second Hall IC 42. In the present embodiment, the angle interval θ is 90 °. As shown in FIG. 5, the first Hall IC
When 40 emits a pulse, the second Hall IC 42 emits a pulse with a delay of 1/4 cycle of this pulse, and the Hall IC 42 emits a pulse.
Pulses are emitted one after another for each of 40 and 42, and the emitted pulses are transmitted from a terminal 52 on the substrate 50 to an EC (not shown).
U (or CPU; control device). To the ECU,
As shown in FIG. 3, a pulse signal line 54 as a lead wire of the Hall ICs 40, 42 having one end fixed to the case 44.
In addition, the drive motor power line 58 is connected to the relay connector 5.
6 are connected.

When the armature 26 reverses, the pulse generation order is reversed. After the second Hall IC 42 emits a pulse, the first Hall IC 40 emits a pulse with a delay of 1/4 cycle of this pulse.

That is, when the armature 26 rotates forward,
The pulse of the first Hall IC 40 rises first, and then
The pulse of the second Hall IC 42 rises. Also, the first
The pulse of the Hall IC 40 falls first, and then the second
The pulse of the Hall IC 42 falls.

When the armature is reversed, the second Hall IC
42 pulse rises first, then the first Hall IC
Forty pulses rise. In addition, the second Hall IC 42
Pulse falls first, and then the first Hall IC 40
Pulse falls.

In the ECU, the pulse of the first Hall IC 40 and the pulse of the second Hall IC 42 are added together, and
The count is incremented by the rotation of the armature 26 in the window glass closing direction or the rotation of the window glass in the upward direction (forward rotation), and is counted down in accordance with the rotation of the armature 26 in the window glass opening direction or the downward direction of the window glass (reverse rotation). That is, the pulse counts of the pulses emitted from the first Hall IC 40 are 1, 3, 5,...
The pulse count of the pulse issued by C42 is 2,
4, 6, ...

The pulse count is, as shown in FIG.
This corresponds to the position where the window glass 24 is raised and lowered.

The control of the ECU when raising the window glass 24 will be described. The pulse count at the lower limit position of the window glass 24 is set to 0, and the pulse count number at the upper limit position of the window glass 24 is set to n + 1.

When a lock current (overcurrent) is generated in the motor 14 in the process of raising the window glass 24, and when the pulse count number does not reach n, the lock current is generated by the generation of the lock current.
The window glass 24 performs an anti-jamming operation that stops rising and immediately descends. When a foreign substance such as a finger is caught between the window glass 24 and the upper edge 25 of the window frame, a lock current is generated in the electric motor 14, but the foreign substance can be easily removed by the above-described pinching operation. In addition, various operations are possible for the anti-jamming operation, such as simply stopping the rising of the window glass 24.

When a lock current is generated in the electric motor 14 during the rising process of the window glass 24, if the pulse count number has reached n, the window glass 24 does not perform the anti-jamming operation even if the lock current is generated. . When the windowpane 24 is closed, a resistance is generated between the windowpane 24 and the upper edge 25 of the window frame to generate a lock current, but the closing operation of the windowpane 24 is performed normally. That is, after the pulse count number n, the dead zone 60 where the closing operation can be performed normally without performing the anti-jamming operation even when the lock current flows.

The ECU detects which order the pulses are generated, and determines whether the armature 26 is rotating forward or backward. Since it is not necessary to perform the anti-jamming operation when the window glass 24 is lowered, the circuit for the anti-jamming operation can be omitted when it is determined that the rotation is reversed, which is convenient. Further, by determining whether the armature 26 is rotated forward or backward, whether the window glass 24 has reached the upper limit limit is determined.
It is possible to determine whether the lower limit end has been reached, and to reset the pulse count at the upper limit position or the lower limit position. For example, even if the pulse count number when the window glass 24 is completely closed does not reach n + 1, or the pulse count number exceeds n + 1, the pulse count number is reset to n + 1 at the ascending limit position of the window glass 24. Accordingly, the correspondence between the pulse count number and the position at which the window glass 24 moves up and down with respect to the window frame can be obtained with high accuracy.

Next, the operation and effect of this embodiment will be described.

With the rotation of the armature 26 of the electric motor 14, a pulse is emitted for each of the Hall ICs 40 and 42.
There is a phase difference between the pulses between the Hall ICs 40 and 42, and the number of pulses with respect to the rotation amount of the armature 26 is twice as large as that of a single Hall IC, and the pulse resolution is increased.

Therefore, the dead zone 60 is 、, which is smaller when there are two Hall ICs than when there is one Hall IC. Since the dead zone 60 is reduced, the window glass can be properly closed and the operation of preventing pinching of even smaller foreign substances can be reliably performed.

Since the order in which the pulses of the Hall ICs 40 and 42 are generated differs depending on whether the armature 26 is normal or reverse, it is possible to determine whether the armature 26 is normal or reverse by detecting this difference.

Further, it is possible to increase the pulse resolution without increasing the number of poles of the magnet 38, and to determine whether the armature 26 is normal or reverse, without providing any additional means. Structure is enough.

When the Hall IC element is exposed in the housing, there is a possibility that foreign matter such as conductive brush powder or flying solder may adhere to between the leads and cause malfunction or failure. If so, the service life would have to be shortened. According to the above configuration, the Hall ICs 40, 4
The element 2 is cut off from the magnet 38 and the armature 26 in the housing 34 (in the motor) by the substrate 50, and is cut off from the magnet 38 and the armature 26 in the housing 34 by the case 44 wall and the housing 34 wall. As a result, it is not exposed in the housing 34, and such a problem does not occur.

Moreover, since the substrate 50 is interposed between the elements of the Hall ICs 40 and 42 and the magnet 38 and the armature 26, when the case 44 is assembled to the wall of the housing 34, the Hall ICs 40 and 42 are
8, the armature 26, the wall of the housing 34, etc., so that the Hall ICs 40, 42
Can ensure the positional accuracy of the assembly.

Further, in this embodiment, the Hall IC
Since the substrate 50 on which the components 40 and 42 are assembled is assembled on the outer surface of the housing 34 from the axial direction of the output gear 36 together with the case 44, the substrate 50 is used for assembling the Hall ICs 40 and 42 in the housing 34. In comparison, it is extremely easy to assemble the substrate 50 or the Hall ICs 40 and 42 themselves. Moreover, the Hall IC 4 to the substrate 50
The relative positional relationship between the Hall ICs 40 and 42 is determined by assembling the Hall ICs 0 and 42.

In this embodiment, the Hall IC 4
The Hall ICs 0 and 42 are assembled by mounting the substrate 50 to the case 44. That is, the Hall IC 40 to be used,
Regardless of the number of holes 42, the hole I can be formed only by mounting
The assembly of C40 and C42 is completed.

Further, as described above, the relative positional relationship of each of the Hall ICs 40 and 42 is determined by assembling the Hall ICs 40 and 42 on the board 50. , 42 can be easily improved, and the detection accuracy of the Hall ICs 40, 42 can be improved by improving the positioning accuracy of the Hall ICs 40, 42.

Further, when assembling the Hall ICs 40 and 42 alone into the case 44, the pulse signal line 54 connected to the Hall ICs 40 and 42 in the case 44 is considered.
In this embodiment, the pulse signal line 54 and the like and the Hall IC 4
Since the terminals 0 and 42 can be connected, the above problem is solved.

The case 44 is mounted on the outer surface (wall) of the housing 34 from the axial direction of the output gear 36.
As described above, at the time of this assembling, the protrusion 45 penetrates the caulking hole 46. Here, as described above, when each projection 45 penetrates the corresponding caulking hole 46, the outer peripheral portion of each projection 45 extends in the direction orthogonal to the axial direction of the output gear 36, and the inner peripheral portion of the caulking hole 46. Accordingly, the movement of the case 44 in a direction orthogonal to the axial direction of the output gear 36 is restricted.

As described above, the movement of the case 44 with respect to the housing 34 is regulated, so that the magnet 3
8, the movement of the Hall ICs 40 and 42 is restricted.
Since the detection accuracy of the Hall ICs 40 and 42 is determined by the relative position with respect to the magnet 38, as described above, the Hall I
As the movement of C40 and C42 is regulated, the Hall IC 4
The detection accuracy of 0 and 42 is improved.

The plurality of caulking holes 46 formed in the case 44 have one caulking hole 46 and the other caulking hole 46 are displaced in the rotation circumferential direction of the armature 26. Furthermore, since the armature 26 is also displaced in the rotation axis direction, the case 44 is positioned outside the housing 34 against vibrations in the circumferential direction and the rotation axis direction of the rotation axis of the armature 26 generated when the electric motor 14 is driven. Firmly fixed to As a result, the displacement of the opposing positions of the Hall ICs 40 and 42 mounted on the substrate 50 in the case 44 and the magnet 38 is prevented, and the rotation speed and the like of the electric motor 14 can be accurately detected over a long period of time.

Further, a plurality of caulking holes 46 formed in the case 44
The case 44 is formed on both sides of the main body of the case 44. In addition, since the space between the caulking hole 46 on one side and the caulking hole 46 on the other side is set to be equal to or larger than the outer diameter (diameter) of the magnet 38 via the main body of the case 44, these caulking holes The case 44 including the portion where the 46 is formed is fixed to the housing 34 so as to straddle the rotation axis of the armature 26. Further, as shown in FIG. 4, the rotation axis of the armature 26 is located between the caulking hole 46 on one side and the caulking hole 46 on the other side (that is, the armature 2 has a plurality of caulking holes 46).
6 is sandwiched).

In the case where only one side of the armature 26 is fixed to the housing along the rotation direction of the armature 26, the non-fixed side vibrates around the fixed side, Further, it is conceivable that such a vibration may cause a problem that the projection 45 comes off from the caulking hole 46 and the case 44 comes off. However, as in the present embodiment, the caulking holes 46
The case 44 is firmly fixed to the housing 34 by forming the protrusion 45 by heat caulking.
The case 44 does not vibrate due to the rotation of 6, and the case 44 does not come off. As a result, Case 4
4. Hall ICs 40 and 42 assembled on the substrate 50 in
The displacement of the facing position between the motor 14 and the magnet 38 is prevented, and the rotation speed and the like of the electric motor 14 can be accurately detected over a long period of time.

Further, in this embodiment, the pulse signal line 54 is drawn out substantially along the axial direction of the motor output shaft 28. Here, as shown in FIG.
8, the worm 30 of the motor output shaft 28
Since the helical gear 32 connected to the helical gear 32 is arranged, a space is easily vacated up to such a helical gear 32. Therefore, such a space is used as an accommodation space for the pulse signal line 54 or the pulse signal line 5.
4 can be used as a space for routing the pulse signal line 54.

To mount the Hall ICs 40 and 42 outside the housing 34, the case 44 is fixed to the outer surface of the housing 34 by screws 48 and heat staking, but other fixing means such as fixing with an adhesive or the like. Is also possible.

In this embodiment, as shown in FIG. 5, the phase difference of the pulse between the Hall ICs 40 and 42 corresponds to 50% of the pulse width, which is particularly preferable. , 42 as long as the pulses are not synchronized. The phase difference can be changed by changing the angle interval θ. However, considering the assembly error of each part, 5 to 95% of the pulse width
Is preferable.

In the present embodiment, the magnet 38
Are two poles, but not limited to two poles, and an even number of plural poles such as four poles and six poles are also possible. The angle interval θ where the phase difference of the pulse between the Hall ICs is 1/4 cycle is 4
5 °, and 30 ° for 6 poles. That is, the angle interval θ = 180 / the number of poles (even number).

Furthermore, in the present embodiment, the number of Hall ICs is two, but the present invention is not limited to this. However, if the Hall ICs are arranged at an angular interval θ, two or more Hall ICs are provided. More than one is possible. In this case, the number of pulse counts is equal to the number of Hall ICs, and the pulse resolution is further increased.

Next, a second embodiment of the present invention will be described with reference to FIGS.

In the present embodiment, the Hall ICs 40, 42
Are fixed to the outer surface of the housing 74 by the stoppers 72. The stopper 72 has one end fixed to the outer surface of the housing 34 and the other end sandwiching the case 70 between the housing 74 and the wall of the housing 74.

If the stopper 72 is formed of a magnetic material such as Fe, the lines of magnetic force of the magnet 38 act outwardly in the radial direction of the magnet 38 toward the stopper 72, and the gap between the stopper 72 and the magnet 38. Interposed Hall ICs 40 and 42
This ensures detection of the magnetic field of the magnet 38 even if it is cut off from the magnet 38 in the housing 74 by the case 70 wall and the housing 74 wall.

The other structure, operation and effect are the same as those of the first embodiment.

The present invention is not limited to the configuration of each of the above embodiments, and various modifications are possible. For example, in each of the above embodiments, the DC motor applied to the jam protection power window has been described, but the electric motor according to the present invention is not limited to the DC motor,
Other electric motors may be used.

In each of the above embodiments, the Hall IC
Is built in the case and mounted outside the housing. However, even if the Hall IC is provided inside the housing, the operation and effect of the present invention are not reduced, and various means for mounting the Hall IC are possible. is there.

[Brief description of the drawings]

FIG. 1 is a perspective view of a main part showing a rotation detection device for an electric motor according to a first embodiment of the present invention.

FIG. 2 is a perspective view showing a power window to which the motor rotation detection device according to the first embodiment is applied.

FIG. 3 is an overall perspective view of the electric motor.

FIG. 4 is a sectional view taken along line 4-4 of FIG. 8;

FIG. 5 is a time chart of a pulse.

FIG. 6 is a diagram showing a vertical position of a window glass corresponding to a pulse count number.

FIG. 7 is a plan view showing the electric motor in a state where the Hall IC is not mounted.

FIG. 8 is a plan view showing the electric motor with the Hall IC mounted.

FIG. 9 is a perspective view showing a motor in a state where a Hall IC is not mounted according to the second embodiment.

FIG. 10 is a perspective view showing an electric motor with a Hall IC mounted according to a second embodiment.

[Explanation of symbols]

14 ... electric motor, 26 ... armature, 34 ...
Housing, 38 ... magnet, 40, 42 ...
Hall IC (magnetic sensor), 44 ... case, 45
..Protrusions (regulators and fixing portions), 46..., Caulking holes (regulators and fixing portions), 50.

 ──────────────────────────────────────────────────続 き Continued on the front page F-term (reference) UA04

Claims (4)

[Claims] An armature having a rotary shaft provided with a worm coaxially and integrally; and an output provided coaxially and integrally with a helical gear meshing with the worm and outputting a rotational force to the outside of the helical gear. A shaft, a magnet provided coaxially and integrally with the armature, and having a plurality of poles in which different poles are alternately arranged in the rotation direction of the armature, and supported on the substrate in a state facing the magnet. A magnetic sensor that emits a number of pulses according to the rotation angle of the magnet accompanying the rotation of the armature, a case that accommodates at least a part of the substrate and holds the substrate, and an axial direction of the output shaft. The width is sufficiently smaller than the width in the direction orthogonal to the axial direction, and is formed in a substantially flat shape as a whole,
At least a portion of the armature including the worm;
A housing in which the helical gear and the magnet are rotatably housed, and the case is mounted on an outer surface of the output shaft in an axial direction of the output shaft; and the case in the mounted state is mounted on the housing. A fixing part for connecting and fixing, and interfering with the case assembled on the outer surface of the housing from a direction orthogonal to an axial direction of the output shaft, and orthogonal to the axial direction of the output shaft. A restricting portion for restricting movement of the case in all directions is formed on the outer surface. 2. The apparatus according to claim 1, further comprising a plurality of fixing portions, wherein the other fixing portion is displaced in the axial direction of the armature with respect to one of the fixing portions, and is also displaced in the rotation direction of the armature. The electric motor according to claim 1, wherein: 3. A component along a rotation radius direction of the armature having a length from one fixed portion to another fixed portion of the plurality of fixed portions is set to be equal to or larger than a diameter of a rotation axis of the armature. 3. The electric motor according to claim 2, wherein: 4. The electric motor according to claim 2, wherein a rotation axis of the armature is located between the plurality of fixing portions.