JPH1132468A - Torque motor - Google Patents

Abstract

(57) [Problem] To provide a torque motor capable of reducing a usage amount of a magnet and obtaining a desired peak torque at an arbitrary rotational position with a simple configuration. SOLUTION: A permanent magnet 43 is provided only on a main pole side of a rotor core 42, and a core projection 44 is formed on a slave pole side of a rotor core 42 paired with the main pole. Since the portion 44a is formed, the amount of magnet used can be reduced without significantly reducing the generated torque. Further, the size of the motor can be reduced by reducing the amount of the magnet used. Furthermore,
A protrusion front end portion 44 is formed at a concentrated portion of the transition magnetic flux between the rotor core 42 and the stator 45 near the solenoid portions 50 and 55.
When “a” is reached, the torque motor 40 generates a peak torque. Therefore, when a high load is applied and a high torque is required, for example, when the valve starts to open, a desired peak torque can be obtained at an arbitrary rotational position by setting the angle range of the core projection 44 to an appropriate range. .

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a torque motor used for a flow control valve or the like.

[0002]

2. Description of the Related Art Conventionally, as a torque motor used for a flow control valve or the like, in order to provide a rotor with a pair of N pole and S pole, the whole rotor is constituted by magnets or a part of the rotor is provided with a rotating shaft. There is known a configuration in which a magnet is provided at a symmetrical position with respect to. As such a torque motor, there is a torque motor disclosed in Japanese Patent Application Laid-Open No. 3-31529.

[0003]

However, according to the structure of the torque motor disclosed in Japanese Patent Application Laid-Open No. 3-31529, the torque generated by the torque motor is limited by the amount of magnet used under the condition that the physique or input current is constant. Limited by Therefore, in order to generate high torque, there is a problem that the amount of the magnet used becomes large and the size of the motor becomes large.

The present invention has been made to solve such a problem, and an object of the present invention is to provide a torque motor capable of reducing the amount of magnets used and achieving downsizing. Another object of the present invention is to provide a torque motor that can obtain a desired peak torque at an arbitrary rotational position with a simple configuration.

[0005]

According to a first aspect of the present invention, there is provided a torque motor comprising: a rotor body having an N pole on one side of a plane parallel to a rotation axis and an S pole on the other side; A magnet may be provided only on a certain main pole side, and a core projection of a magnetic material may be formed on the slave pole side paired with the main pole, so that the amount of magnet used can be reduced. Further, by reducing the amount of magnets used, the size of the motor can be reduced. Furthermore, when the projection reaches the concentrated portion of the transition magnetic flux between the rotor body and the stator near the solenoid portion,
Since a high generated torque can be obtained, it is possible to suppress a reduction in generated torque due to a reduction in the amount of magnet used.

According to the torque motor of the present invention, the magnet and the core projection are asymmetric with respect to the rotation axis of the rotor body. Therefore, when the core projection reaches the concentrated portion of the transition magnetic flux between the rotor body and the stator in the vicinity of the solenoid, the peak torque of the motor can be obtained. It is possible to obtain a torque curve with a high peak torque. Therefore, a desired peak torque can be obtained at an arbitrary rotational position with a simple configuration.

According to the torque motor of the third aspect of the present invention, since the angle range occupied by the magnet and the core projection in the circumferential direction with respect to the axis of the rotor main body is different, the rotor main body and the stator in the vicinity of the solenoid portion are different from each other. When the core protrusion reaches the concentrated portion of the transition magnetic flux, the peak torque of the motor can be obtained. Therefore, when a high load is applied and a high torque is required, for example, when the valve starts to open, a desired peak torque can be obtained at an arbitrary rotational position by selecting an appropriate angle range of the slave electrode. .

According to the torque motor of the present invention, the rotation front edge of the core projection is inclined in the axial and radial directions, in the axial and circumferential directions, or in the axial, radial and circumferential directions. Or it has a step shape. For this reason, by making the inclined surface of the rotation front edge of the core projection an appropriate shape or having an appropriate inclination angle, the concentration of the transition magnetic flux between the rotor main body and the stator near the solenoid portion and the concentration of the concentrated portion are reduced. The movement is adjusted, and a torque corresponding to the shape and the inclination angle of the inclined surface at the front edge of rotation can be obtained. Therefore, the torque curve of the motor can be formed into a desired shape with a simple configuration.

According to the torque motor according to the fifth aspect of the present invention, since the magnet projects on the outer periphery of the rotor body, the distance between the stator and the magnet can be reduced. Therefore, the generated torque of the motor can be increased.

[0010]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing a first embodiment of the present invention; (First Embodiment) FIGS. 1 and 2 show a throttle valve control apparatus using a torque motor according to a first embodiment of the present invention. The throttle valve control device 10 shown in FIG. 2 does not have a mechanism for mechanically linking the accelerator and adjusting the opening of the throttle valve 13 in accordance with the amount of depression of the accelerator.
The opening of the throttle valve 13 is adjusted only by 0.

The throttle body 11 of the throttle valve control device 10 rotatably supports a throttle shaft 12 via bearings 15 and 16. Throttle valve 13
Is formed in a disk shape, and a screw 1 is
It is fixed at 4. When the throttle valve 13 rotates together with the throttle shaft 12, the throttle body 1
The flow passage area of the intake passage 11a formed by the inner wall of the first intake passage 11 is adjusted, and the flow rate of intake air passing through the intake passage 11a is controlled.

A throttle lever 21 is press-fitted and fixed to one end of the throttle shaft 12, and the throttle lever 21 rotates together with the throttle shaft 12. The stopper screw 22 abuts on the throttle lever 21 to define the fully closed position of the throttle valve 13. By changing the screwing amount of the stopper screw 22, the fully closed position of the throttle valve 13 can be adjusted.

The rotation angle sensor 30 includes a throttle lever 2
1, a contact portion 31, a substrate 32 coated with a resistor, and a housing 33. Contact part 3
1 is press-fitted into the throttle shaft 12 and rotates together with the throttle shaft 12. The substrate 32 is fixed to the housing 33, and the contact portion 31 slides on the resistor applied to the substrate 32. A constant voltage of 5 V is applied to the resistor applied to the substrate 32, and when the sliding position between the resistor and the contact portion 31 changes according to the opening of the throttle valve 13, the output voltage value changes. An electronic control unit (ECU) (not shown) receives the output voltage value from the rotation angle sensor 30 and detects the opening of the throttle valve 13.

A torque motor 40 is formed at the other end of the throttle shaft 12 by the rotor 41, the stator 45, and the pair of solenoids 50 and 55 shown in FIG. The end of the torque motor 40 is covered by the cover 20. The rotation direction of the rotor 41 is clockwise as shown in FIG. In FIG. 1A, an axis orthogonal to an imaginary line connecting the solenoid unit 50 and the solenoid unit 55 is defined as an axis Z of the stator 45.

A rotor 41 shown in FIG. 1B has a rotor core 42 as a rotor body press-fitted and fixed to the throttle shaft 12, and a main pole side as one side of a plane parallel to the rotation axis Y of the rotor core 42. , And is rotatably housed in a housing hole 45 a formed by the inner wall of the stator 45. Rotor core 42
Is formed in a cylindrical shape having a fan-shaped core projection 44 projecting in the radial direction of the rotor, provided on the side of the auxiliary pole that forms a pair with the main pole, and is press-fitted and fixed to the other end of the throttle shaft 12. . The core projection 44 has a projection front end 44a as a rotation front edge in the rotation direction of the rotor 41 and a projection rear end 44b in the rotation direction of the rotor 41. The protrusion front end 44a and the protrusion rear end 44b are formed substantially parallel to the rotation axis Y. Projection front end 44
The angle range α occupied in the circumferential direction with respect to the rotation axis Y from a to the projection rear end 44b is about 130 °. Permanent magnet 4
3 is formed in an arc shape with an angle range β occupying in the circumferential direction with respect to the rotation axis Y from one end to the other end of about 140 °, and a core projection 4 with respect to the rotation axis Y on the outer periphery of the rotor core 42.
4 is bonded and fixed to the opposite side of about 180 °. That is, the core projection 44 and the permanent magnet 43 have an asymmetric shape with respect to the rotation axis Y. The permanent magnet 43 is magnetized radially from the rotation axis Y of the rotor 41, that is, radially. The permanent magnet 43 is a so-called rare earth magnet that generates a high magnetic force, such as a neodymium-based or samarium-cobalt-based magnet.

The stator 45 is formed by laminating thin plates made of a magnetic material in the axial direction of the throttle shaft 12, and rotatably accommodates the rotor 41 in an accommodation hole 45a. The stator 45 has a continuous slotless structure around the rotor 41. Solenoid part 5
0 and 55 are coils 5 on iron cores 51 and 56, respectively.
2 and 57 are wound around the stator 45.
Is press-fitted and fixed. A control current is supplied to the coils 52 and 57 from a terminal 60.

The return spring 17 as the urging means shown in FIG. 2 has one end fixed to the rotor core 42,
The other end is fixed to a screw 18 to urge the throttle valve 13 in the closing direction. Next, the throttle valve control device 10
The operation of will be described. (1) During normal driving The normal driving mode of the vehicle is ISC (idle speed control).
l) Normal driving, cruise control, etc. The opening of the throttle valve 13 in each mode is determined based on an engine operating state such as an accelerator pedal depression amount and an engine speed.
The control current calculated by the CU is supplied to the coils 52 and 57 according to the calculated opening.

The torque for rotating the rotor 41, which is generated when the coils 52 and 57 are energized, is greater than the urging force of the return spring 17, so that the rotor 41 can rotate against the urging force of the return spring 17. . The opening of the throttle valve 13 that rotates with the rotation of the rotor 41 is detected by the rotation angle sensor 30 and fed back to the ECU. EC based on this opening signal
The control current supplied from U to the coils 52 and 57 is adjusted. By detecting the opening of the throttle valve 13, the torque acting on the rotor 41 is prevented from fluctuating due to a temperature change or the like, and the opening of the throttle valve 13 can be controlled with high accuracy.

(2) At the time of failure The throttle opening 13 required by the ECU and the actual throttle valve 1 detected by the rotation angle sensor 30 are calculated.
If the opening degree of the throttle valve 3 does not match, it is determined that the opening degree control of the throttle valve 13 by the ECU has failed, and
Sends a signal to close the throttle valve 13. Then, since the throttle valve 13 returns to the fully closed position by the urging force of the return spring 17, the throttle valve 13 can be prevented from being excessively opened.

Since the ECU has a sub-ECU that constantly diagnoses the failure of the ECU, if the ECU fails, the coils 52 and 5 are instructed by the sub-ECU.
The control current supplied to 7 is cut off. Therefore, EC
Even if U fails, the throttle valve 13 can be fully closed by the urging force of the return spring 17. next,
The operation of the core projection 44 of the rotor core 42 of the torque motor 40 will be described.

FIGS. 3 (A), 3 (B) and 3 (C) show changes in the flow of magnetic flux due to the rotation of the rotor 41, and indicate the portions A, B and C of the torque curve shown in FIG.
Corresponding to each part. The angle shown in FIG. 4 is 0 ° when the axis Z of the stator 45 shown in FIG. 1A divides the permanent magnet 43 shown in FIG. Is the rotation angle when the rotor 41 rotates clockwise. The arrows shown in FIG. 3 indicate the direction of flow of the magnetic flux, and the density of the arrows indicates the density of the magnetic flux. Magnetic flux concentrates between the rotor core 42 and the stator 45 near the solenoids 50 and 55. Therefore, the solenoid unit 50
The torque of the torque motor 40 is determined by the density and direction of the transition magnetic flux between the rotor core 42 and the stator 45 near 55 and 55. In particular, when the crossover magnetic flux in the X portion of the stator 45 corresponding to the rotation front edge of the core projection in the X portion shown in FIG. 3 is maximized and the flow direction of the magnetic flux in the X portion becomes the tangential direction of the rotor 41, the torque motor 40 Generates peak torque.

In FIG. 3A, a core projection 4 is formed on the X portion.
Since the front end portion 44a of the protrusion 4 does not reach, the crossover magnetic flux in the tangential direction of the rotor 41 contributing to the torque generation in the X section is dense, but a sufficient crossover magnetic flux cannot be obtained. For this reason,
As shown in part A of FIG. 4, the torque motor 40 does not generate peak torque. In FIG. 3B, since the projection front end portion 44a of the core projection 44 reaches the X portion,
The crossover magnetic flux in the tangential direction of the rotor 41 that contributes to the torque generation in the X section is dense, and a sufficient crossover magnetic flux is obtained, so that the torque is maximized. For this reason, the torque motor 40 generates a peak torque, as shown in part B of FIG.

In FIG. 3C, the core projection 4
The projection front end 44a of No. 4 has reached. However, since the projection front end portion 44a passes through the X portion, the tangential magnetic flux in the tangential direction of the rotor 41 that contributes to the torque generation in the X portion is sparse, and a sufficient magnetic flux cannot be obtained. For this reason, FIG.
As shown in the portion C of FIG.

Next, the rotor core 42 of the torque motor 40
The effect of the core projection 44 will be described in comparison with a comparative example. In the comparative example shown in FIG. 5A, the rotor 61 is composed of a cylindrical rotor core 62 and arc-shaped permanent magnets 63 and 64. The permanent magnets 63 and 64 are formed in an arc shape having an angle range β occupying in the circumferential direction with respect to the rotation axis Y from one end to the other end of about 140 °, and the rotation axis Y of the rotor 61 on the outer periphery of the rotor core 62. And 180 ° symmetrical with respect to each other. That is, the permanent magnet 63 and the permanent magnet 64 have a symmetric shape with respect to the rotation axis Y. Other configurations are the same as those of the first embodiment. FIG. 5B shows the rotor 41 of the first embodiment.

FIG. 6 shows the relationship between the rotation angle and the torque curve between the rotor 41 of the first embodiment and the rotor 61 of the comparative example. The angle shown in FIG. 6 is 0 ° when the axis Z of the stator 45 shown in FIG. 1A bisects the permanent magnet 43 shown in FIG. Is the rotation angle when the rotor 41 rotates clockwise.
In the comparative example, a flat torque curve is obtained that is substantially line-symmetric with respect to the central axis at an angle of 90 °. On the other hand, in the first embodiment, a higher peak torque is obtained at the angle of about 70 ° than in the comparative example. Therefore, the first embodiment is particularly effective when a high load is applied such as when the valve starts to open and a high torque is required.

(Second Embodiment) FIG. 7 shows a second embodiment of the present invention.
Shown in The substantially same parts as those in the first embodiment are denoted by the same reference numerals. The rotor 41 includes a rotor core 42 and a permanent magnet 43, and the rotor core 42 is formed in a cylindrical shape having a fan-shaped core protrusion 44. The core projection 44 has a projection front end portion 44a formed forward of the rotor 41 in the rotation direction, and a projection rear end portion 44b formed rearward of the rotor 41 in the rotation direction. The protrusion front end 44a and the protrusion rear end 44b are formed substantially parallel to the rotation axis Y. Projection front end 44
The angle range α occupied in the circumferential direction with respect to the rotation axis Y from a to the projection rear end 44b is about 100 °. Permanent magnet 4
3 has an angle range β occupied in the circumferential direction with respect to the rotation axis Y from one end to the other end, and is formed in an arc shape of about 140 °. From the position of about 180 ° of the projection 44, the projection rear end 44
It is adhesively fixed at a position shifted to the b side. That is, the core projection 44 and the permanent magnet 43 are asymmetrical with respect to the rotation axis Y, and are provided at asymmetrical positions.

FIG. 6 shows the relationship between the rotation angle of the rotor 41 and the torque curve of the second embodiment. In the second embodiment, a higher peak torque is obtained at an angle of about 115 ° than in the comparative example. Therefore, in the second embodiment, the peak position is shifted to a higher angle side than the first embodiment without changing the height of the peak torque by making the angle range of the core projection 44 smaller than that of the first embodiment. be able to.

(Third Embodiment) FIG. 8 shows a third embodiment of the present invention.
Shown in The substantially same parts as those in the first embodiment are denoted by the same reference numerals. The rotor 41 includes a rotor core 42 and a permanent magnet 43, and the rotor core 42 is formed in a cylindrical shape having a fan-shaped core protrusion 44. The core projection 44 has a projection front end portion 44a formed forward of the rotor 41 in the rotation direction, and a projection rear end portion 44b formed rearward of the rotor 41 in the rotation direction. The protrusion front end 44a and the protrusion rear end 44b are formed substantially parallel to the rotation axis Y. Projection front end 44
The angle range α occupied in the circumferential direction with respect to the rotation axis Y from a to the projection rear end 44b is about 70 °. Permanent magnet 43
Has an angle range β occupied in the circumferential direction with respect to the rotation axis Y from one end to the other end in an arc shape of about 140 °, and has a core projection with respect to the rotation axis Y of the rotor 41 on the outer periphery of the rotor core 42. 44 from the position of about 180 °
It is adhesively fixed at a position shifted to the b side. That is, the core projection 44 and the permanent magnet 43 are asymmetrical with respect to the rotation axis Y, and are provided at asymmetrical positions.

FIG. 6 shows the relationship between the rotation angle of the rotor 41 and the torque curve of the third embodiment. In the third embodiment, a higher peak torque is obtained at an angle of about 135 ° than in the comparative example. For this reason, in the third embodiment, the angle range of the core projection 44 is made smaller than that of the second embodiment, so that the peak position can be shifted to a higher angle side than the second embodiment without changing the height of the peak torque. Can be shifted.

In the first to third embodiments of the present invention, the permanent magnets 43 are provided only on the main pole side of the rotor core 42, and the core projections 44 are formed on the slave pole side of the rotor core 42 paired with the main pole. , The front end portion 44a of the core
Is formed, it is possible to reduce the amount of magnet used without significantly reducing the motor torque. Further, by reducing the amount of magnets used, the size of the motor can be reduced. Furthermore, the solenoid units 50 and 55
When the protrusion front end 44a reaches the concentrated portion of the transition magnetic flux between the nearby rotor core 42 and the stator 45, the torque motor 40 generates a peak torque. Therefore, when a high load is applied and a high torque is required, for example, when the valve starts to open, the angular range occupied in the circumferential direction with respect to the rotation axis Y of the core projection 44 can be changed to an appropriate range by changing the angle range. A desired peak torque can be obtained at the rotational position.

(Fourth Embodiment) FIG. 9 shows a fourth embodiment of the present invention.
Shown in The substantially same parts as those in the first embodiment are denoted by the same reference numerals. The rotor 41 includes a rotor core 42 and a permanent magnet 43, and a core projection 44 is formed on the rotor core 42. The core projection 44 has a projection front end 44a that is inclined in the axial direction and the circumferential direction. Projection front end 44
9A has an inclined surface 441 whose upper portion in FIG. 9 is inclined in a direction approaching the permanent magnet 43, and whose lower portion in the vertical direction is the permanent magnet 4.
3 has an inclined surface 442 inclined in a direction away from the center 3, and a central portion protrudes toward the permanent magnet 43. That is, the front end 44a of the projection has an inclined surface 4 inclined in the axial direction and the circumferential direction.
41 and 442. The core projection 44 has a projection rear end 44b substantially parallel to the rotation axis Y. The angle range β occupied by the permanent magnet 43 in the circumferential direction with respect to the rotation axis Y from one end to the other end is about 140 °.
, And is adhesively fixed to the opposite side of the core projection 44 by about 180 ° with respect to the rotation axis Y on the outer periphery of the rotor core 42.

FIG. 12 shows the relationship between the rotation angle of the rotor 41 and the torque curve of the fourth embodiment. The angle shown in FIG. 12 corresponds to the rotor 41 when the axis Z of the stator 45 shown in FIG. 1A bisects the permanent magnet 43 shown in FIG. 9 in the circumferential direction.
Is the rotation angle when the rotor 41 rotates clockwise, assuming that the angle is 0 °. FIG. 12 also shows the relationship between the rotation angle and the torque curve of the rotor 61 of the comparative example shown in FIG. In the fourth embodiment, although the torque is slightly lower than that in the comparative example, a flat torque curve is obtained almost symmetrically with respect to the central axis at an angle of 90 °.

(Fifth Embodiment) FIG. 1 shows a fifth embodiment of the present invention.
0 is shown. The substantially same parts as those in the first embodiment are denoted by the same reference numerals. The rotor 41 includes a rotor core 42 and a permanent magnet 43, and a core projection 44 is formed on the rotor core 42. The core projection 44 has a projection front end 44a that is inclined in the axial direction and the circumferential direction. Projection front end 4
4a has an inclined surface 441 that is inclined in a direction away from the permanent magnet 43 from vertically above to vertically below in FIG. That is, the projection front end 44a has an inclined surface 441 that is inclined in the axial direction and the circumferential direction. Also, the core projection 44
, A projection rear end portion 44b is formed substantially parallel to the rotation axis Y. The angle range β occupied by the permanent magnet 43 in the circumferential direction with respect to the rotation axis Y from one end to the other end is approximately 140.
It is formed in the shape of a circular arc and is adhesively fixed to the opposite side of the core projection 44 by about 180 ° with respect to the rotation axis Y on the outer periphery of the rotor core 42.

FIG. 12 shows the relationship between the rotation angle of the rotor 41 and the torque curve of the fifth embodiment. In the fifth embodiment, a flat torque curve substantially similar to that of the fourth embodiment is obtained. (Sixth Embodiment) FIG. 11 shows a sixth embodiment of the present invention. The substantially same parts as those in the first embodiment are denoted by the same reference numerals.

The rotor 41 includes a rotor core 42 and a permanent magnet 4
The rotor core 42 has a core projection 44 formed thereon. The core projection 44 has a projection front end 44a that is inclined in the axial direction and the circumferential direction. The projection front end portion 44a has an inclined surface 441 inclined in a direction away from the permanent magnet 43 from vertically above to vertically below in FIG.
have. That is, the projection front end 44a has an inclined surface 441 that is inclined in the axial direction and the circumferential direction. The core projection 44 has a permanent magnet 4 extending vertically upward and vertically downward.
A projection rear end portion 44b having an inclined surface 443 inclined in a direction approaching 3 is formed. The permanent magnet 43 is formed in an arc shape with an angle range β occupied in the circumferential direction with respect to the rotation axis Y from one end to the other end of about 140 °. About 180 of 44
° Adhesively fixed to the other side.

FIG. 12 shows the relationship between the rotation angle of the rotor 41 and the torque curve of the sixth embodiment. In the sixth embodiment, a flat torque curve substantially similar to that of the fourth and fifth embodiments is obtained. In the fourth to sixth embodiments of the present invention, the protrusion front end portion 44a having the inclined surface 441 or 442 that is inclined in the axial direction and the circumferential direction is attached to the core protrusion 4 of the rotor core 42.
4, the generated torque is reduced significantly by setting the inclination angle of the front end 44a of the projection to an appropriate angle, or forming the inclined surface 441 or 442 to an appropriate shape, or a stair-like shape approximating the inclination. The torque curve can be made flat without causing the torque curve. further,
Since the torque characteristics of the torque motor 40 are not affected by the shape of the protrusion rear end portion 44b, design and manufacture are easy.
In the fourth to sixth embodiments, the front end of the projection may have an inclined surface inclined in the axial direction and the radial direction, or in the axial direction, the radial direction and the circumferential direction.

In the above embodiments, the torque motor of the present invention is applied to the throttle valve control device. However, it goes without saying that the torque motor of the present invention can be applied to a flow control valve for any use.

[Brief description of the drawings]

FIG. 1A is a view of a throttle control device using a torque motor according to a first embodiment of the present invention, which is taken along a direction I in which a cover of FIG. 2 is removed, and FIG. FIG. 2 is a perspective view illustrating a rotor of the torque motor according to the first embodiment.

FIG. 2 is a sectional view showing a throttle control device using a torque motor according to a first embodiment of the present invention.

FIG. 3 is a schematic diagram showing a change in magnetic flux flow due to rotation of a rotor of the torque motor according to the first embodiment of the present invention.

FIG. 4 is a characteristic diagram showing a relationship between a rotation angle of a rotor and a torque of the torque motor according to the first embodiment of the present invention.

FIG. 5A is a perspective view illustrating a rotor of a torque motor of a comparative example, and FIG. 5B is a perspective view illustrating a rotor of the torque motor according to the first embodiment of the present invention.

FIG. 6 is a characteristic diagram showing a relationship between a rotation angle of a rotor of a torque motor and a torque according to first to third embodiments of the present invention and a comparative example.

FIG. 7 is a perspective view illustrating a rotor of a torque motor according to a second embodiment of the present invention.

FIG. 8 is a perspective view showing a rotor of a torque motor according to a third embodiment of the present invention.

FIG. 9 is a perspective view illustrating a rotor of a torque motor according to a fourth embodiment of the present invention.

FIG. 10 is a perspective view showing a rotor of a torque motor according to a fifth embodiment of the present invention.

FIG. 11 is a perspective view showing a rotor of a torque motor according to a sixth embodiment of the present invention.

FIG. 12 is a characteristic diagram showing a relationship between a rotation angle of a rotor of a torque motor and a torque according to fourth to sixth embodiments of the present invention and a comparative example.

[Explanation of symbols]

 Reference Signs List 10 Throttle valve control device 11 Throttle body 12 Throttle shaft 13 Throttle valve 17 Return spring 40 Torque motor 41 Rotor 42 Rotor core (rotor main body) 43 Permanent magnet 44 Core projection 44a Projection front end (rotation front edge) 44b Projection rear end 45 Stator 50, 55 Solenoid part 52, 57 Coil 441, 442, 443 Inclined surface

Claims (5)

[Claims] An N-side is provided on one side of a plane parallel to the rotation axis.
A rotor, a rotor body having an S pole on the other side, a stator positioned radially outside of the rotor body, mounted on the stator, and generates a magnetic force when energized,
A solenoid portion for rotating the rotor main body by the magnetic force; a main pole on one side of the rotor main body; a magnet provided on the main pole side; and a sub pole side paired with the main pole of the rotor main body. A torque motor comprising: a core protrusion provided in a convex shape in a rotor radial direction. 2. The torque motor according to claim 1, wherein the magnet and the core protrusion are provided on the rotor main body and are asymmetric with respect to the rotation axis. 3. The angle range occupied by the magnet in the circumferential direction with respect to the axis is different from the angle range occupied by the core projection in the circumferential direction with respect to the axis. Torque motor. 4. A rotating front edge of the core projection has an inclined surface or a stepped shape inclined in an axial direction and a radial direction, an axial direction and a circumferential direction, or an axial direction and a radial direction and a circumferential direction. The torque motor according to claim 2 or 3, wherein 5. The torque motor according to claim 1, wherein the magnet projects from an outer periphery of the rotor body.