JP2009216229A - Valve device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a valve device for suppressing the impairment of the symmetry of a magnetic field as a result that magnets 21A, 21B held at an inner peripheral edge 20 are pulled to the inner peripheral edge 20 with the thermal expansion of a resin rotor 15 mounted at one end of a valve shaft 3. <P>SOLUTION: The magnets 21A, 21B are arranged so that an axial center flux perpendicular line 32 being perpendicular to the direction of a magnetic flux formed on an axial center 31 of the valve shaft 3 and passing through the axial center 31 is oriented to the middle of a gear setting range 33. Thus, the direction of strongly operating tensile force with thermal expansion corresponds to the direction of the axial center flux perpendicular line 32. The magnetic field is therefore moved in parallel to the direction of strongly operating the tensile force while minimizing damage to its symmetry. Even when the magnets 21A, 21B are pulled to the inner peripheral edge 20, the impairment of the symmetry of the magnetic field is suppressed. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a valve device that decelerates the output of a motor and transmits it to a valve shaft and drives the valve shaft by the decelerated output.

  2. Description of the Related Art Conventionally, in a valve device such as a throttle device for supplying intake air to an engine, a gear 100 is provided at one end of the valve shaft, as shown in FIG. A rotating body 101 is mounted (see, for example, Patent Document 1). The rotating body 101 is provided in an annular plate shape and has a gear 100 at a part of the outer peripheral edge 102. A magnet 104 and a yoke 105 for detecting the rotation angle of the valve shaft are mounted on the inner peripheral edge 103. ing. Then, for example, the magnetic flux density in the vicinity of the axis of the valve shaft is sensed by a Hall element (not shown) and the rotation angle of the valve shaft is detected.

In recent years, for the purpose of reducing the weight, the tendency of switching the material of the rotating body 101 from a nonmagnetic metal to a resin has become prominent (see, for example, Patent Document 2).
By the way, since the resin has a larger thermal expansion coefficient and thermal contraction ratio than the metal, when the annular plate-like rotating body 101 is provided by resin molding, the inner and outer peripheral edges 103 and 102 are expanded due to thermal expansion. As a result, the ring width (difference between the outer diameter and the inner diameter) is increased.

  For this reason, as shown in FIG. 5B, the magnet 104 and the yoke 105 are irregularly displaced to the outer peripheral side due to the thermal expansion of the rotating body 101, and the magnetic field formed by the magnet 104 is formed. There is a possibility that the symmetry of the is impaired. As a result, the magnetic flux density sensed by the Hall element changes, so that the rotation angle detection characteristics may vary with temperature.

  Further, there is a possibility that an air gap is generated between the magnet 104 and the yoke 105 due to the thermal expansion of the rotating body 101, and the symmetry of the magnetic field may be further lost due to the generation of the air gap.

  Similar problems may occur when the yoke 105 is not attached to the rotating body 101 but only two magnets 104 are attached to the rotating body 101 (see, for example, Patent Document 3). reference). That is, due to the thermal expansion of the rotating body 101, as shown in FIG. 6B, the magnet 104 is pulled to the inner peripheral edge 103 and irregularly displaced to the outer peripheral side, and the symmetry of the magnetic field formed by the magnet 104 is increased. There is a risk of damage.

Further, in the rotating body 101 of FIG. 6, the two magnets 104 are opposed to each other in the circumferential direction to form an air gap, and this air gap may expand due to the thermal expansion of the rotating body 101. As a result, as in the case of FIG. 5, the symmetry of the magnetic field may be further impaired.
Japanese Patent No. 3893907 JP 2007-47183 A European Patent Application No. 1061341

  The present invention has been made to solve the above-described problems, and a magnet or the like held on the inner peripheral edge of the rotating body by the thermal expansion of the resin-made rotating body attached to one end of the valve shaft. It is to suppress the symmetry of the magnetic field from being pulled by the peripheral edge.

[Means of Claim 1]
The valve device according to claim 1 is for decelerating and transmitting the output of the motor to the valve shaft, and driving the valve shaft by the decelerated output. An annular plate-like resin-made rotating body that rotates together with the rotating plate is provided.
Further, a gear is provided at a part of the outer peripheral edge of the rotating body, and the reduced output is transmitted to the valve shaft via the gear. In addition, two magnets for detecting the rotation angle of the valve shaft are held along the inner peripheral edge of the rotating body, and the two magnets are arranged symmetrically with respect to the axis of the valve shaft as a symmetric axis. A magnetic flux is formed on the axial center. A straight line passing through the axis of the valve shaft and perpendicular to the direction of the magnetic flux formed on the axis of the valve shaft is directed to the middle of the circumferential direction setting range of the gear.

  When the ring width is not constant in the circumferential direction, the larger the ring width, the more the inner peripheral edge is enlarged, and the greater the tensile force acting on the magnet or the like. Further, when the ring width is large in a predetermined circumferential range, the inner peripheral edge has a larger diameter in a circumferential range where the ring width is large, as the circumferential distance from the circumferential range where the ring width is small. Strong tensile force.

  Here, in a rotating body having a gear, the circumferential setting range of the gear (hereinafter referred to as the gear setting range) is larger than the circumferential range where the gear is not provided (hereinafter referred to as the gear non-setting range). Is big. For this reason, the inner peripheral edge included in the gear setting range has a significantly larger diameter and a stronger tensile force than the inner peripheral edge included in the gear non-setting range. Further, within the gear setting range, the larger the circumferential distance from the gear non-setting range, that is, the middle of the gear setting range, the larger the inner peripheral diameter is, and the stronger the tensile force is.

  Therefore, a straight line that passes through the valve shaft axis and is perpendicular to the direction of the magnetic flux formed on the axis of the valve shaft (hereinafter, this straight line is referred to as the “axis magnetic flux orthogonal line”) is set in the circumferential direction of the gear. Two magnets are arranged on the inner peripheral edge of the rotating body so as to be oriented in the middle of the range. That is, the direction of the axial center line orthogonal to the direction in which the tensile force acts most strongly is matched. As a result, the magnetic field can be translated in the direction in which the tensile force is most strongly applied, with minimal loss of symmetry. For this reason, even if a magnet etc. are pulled to an inner periphery, it can suppress that the symmetry of a magnetic field is impaired.

[Means of claim 2]
According to the valve device of the second aspect, the two magnets are provided in a columnar shape and are held so that their longitudinal direction is parallel to the axial direction, and are held along the inner peripheral edge of the rotating body. The two yokes are sandwiched in the circumferential direction. Of the two magnets, one circumferential end of one magnet and the other circumferential end of the other magnet are magnetized to the same polarity, and the other circumferential end of one magnet and the circumference of the other magnet are magnetized. The one end of the direction is magnetized to the same polarity. A straight line connecting the two magnets is oriented in the middle of the circumferential setting range of the gear.

  This means shows an aspect in which the axis of magnetic flux orthogonal line is directed in the middle of the circumferential setting range of the gear. That is, according to this means, the straight line connecting the two magnets coincides with the axial magnetic flux orthogonal line, and the two magnets are arranged in the direction and position where the tensile force due to thermal expansion is most strongly applied. Thereby, variation in the displacement direction of the individual magnets and the yoke due to the thermal expansion of the rotating body is suppressed, and the magnets and the yoke are displaced in the same direction while maintaining the relative positional relationship before the displacement. For this reason, the possibility that an air gap is generated due to thermal expansion between the magnet and the yoke is reduced, and further damage to the symmetry of the magnetic field is suppressed.

[Means of claim 3]
According to the valve device of the third aspect, the gear, the two magnets, and the two yokes are in the same position in the axial direction.
As a result, the tensile force at the inner periphery causes all components to act on the magnet and the yoke without generating a component force. For this reason, the magnet and the yoke are more strongly pulled toward the inner peripheral edge and displaced in the same direction while maintaining the relative positional relationship before the displacement. For this reason, the possibility that an air gap is generated between the magnet and the yoke can be further reduced.

[Means of claim 4]
According to the valve device of the fourth aspect, the two magnets are provided in the divided cylindrical body having a thickness in the radial direction, and are held so that the outer peripheral edge thereof is along the inner peripheral edge of the rotating body. Two columnar gaps are formed facing each other. The center of the inner peripheral edge of one of the two magnets and the center of the inner peripheral edge of the other magnet are magnetized with different polarities. A straight line connecting the two columnar gaps is oriented in the middle of the circumferential setting range of the gear.

  This means shows one aspect in which the axis perpendicular to the magnetic flux of the core is directed to the middle of the circumferential direction setting range of the gear. That is, according to this means, the two ends of the two magnets in the circumferential direction are arranged in the direction and position where the straight line connecting the two columnar gaps coincides with the axis perpendicular to the axial magnetic flux and the tensile force due to thermal expansion acts most strongly. The Thereby, the dispersion | variation in the displacement direction of each magnet by the thermal expansion of a rotary body is suppressed, and a magnet is displaced to the same direction, maintaining the relative positional relationship before a displacement. For this reason, the possibility that the columnar gap expands due to thermal expansion is reduced, and further damage to the symmetry of the magnetic field is suppressed.

[Means of claim 5]
According to the valve device of the fifth aspect, the gear and the two magnets are in the same position in the axial direction.
As a result, all components of the tensile force at the inner peripheral edge act on the magnet without generating a component force. For this reason, the magnet is more strongly pulled to the inner peripheral edge and displaced in the same direction while maintaining the relative positional relationship before the displacement. For this reason, the possibility that the columnar gaps may be further reduced.

The valve device of the best mode 1 decelerates the output of the motor and transmits it to the valve shaft, and drives the valve shaft by the decelerated output. The valve device is attached to one end in the axial direction of the valve shaft and is connected to the valve shaft. A rotating body made of a resin material having a rotating annular plate shape is provided.
Further, a gear is provided at a part of the outer peripheral edge of the rotating body, and the reduced output is transmitted to the valve shaft via the gear. In addition, two magnets for detecting the rotation angle of the valve shaft are held along the inner peripheral edge of the rotating body, and the two magnets are arranged symmetrically with respect to the axis of the valve shaft as a symmetric axis. A magnetic flux is formed on the axial center. A straight line passing through the axis of the valve shaft and perpendicular to the direction of the magnetic flux formed on the axis of the valve shaft is directed to the middle of the circumferential direction setting range of the gear.

The two magnets are provided in a columnar shape and are held so that their longitudinal direction is parallel to the axial direction, and sandwiched in the circumferential direction by two yokes held along the inner peripheral edge of the rotating body. ing. Of the two magnets, one circumferential end of one magnet and the other circumferential end of the other magnet are magnetized to the same polarity, and the other circumferential end of one magnet and the circumference of the other magnet are magnetized. The one end of the direction is magnetized to the same polarity. A straight line connecting the two magnets is oriented in the middle of the circumferential setting range of the gear.
Further, the gear, the two magnets, and the two yokes are in the same position with respect to the axial direction.

According to the valve device of the best mode 2, the two magnets are provided in the divided cylindrical body having a thickness in the radial direction, and are held so that their outer peripheral edges are along the inner peripheral edge of the rotating body, and are opposed to the circumferential direction. Thus, two columnar gaps are formed. The center of the inner peripheral edge of one of the two magnets and the center of the inner peripheral edge of the other magnet are magnetized with different polarities. A straight line connecting the two columnar gaps is oriented in the middle of the circumferential setting range of the gear.
Furthermore, the gear and the two magnets are in the same position with respect to the axial direction.

[Configuration of Example 1]
The configuration of the valve device 1 according to the first embodiment will be described with reference to FIGS. 1 and 2.
The valve device 1 decelerates the output of the motor 2 and transmits it to the valve shaft 3, and drives the valve body 4 by the output transmitted to the valve shaft 3 to operate the opening of the fluid flow path. For example, the present invention is applied to a throttle device for supplying intake air to an engine (not shown). That is, the valve device 1 rotates together with the valve shaft 3 by the motor 2 that generates an output, the speed reduction mechanism 5 that decelerates the output of the motor 2 and transmits the output to the valve shaft 3, and the output transmitted from the speed reduction mechanism 5. A valve body 4 and a rotation angle detection device 6 that detects the rotation angle of the valve shaft 3 are provided.

  Then, a detection signal of the rotation angle detection device 6 is input to a predetermined electronic control device (not shown: hereinafter referred to as an ECU), and the ECU determines, for example, the opening degree of the intake passage based on the detection signal. At the same time, various control processes using the opening of the intake passage are executed. The motor 2 is, for example, a known DC motor, and the energization amount is controlled by a command from the ECU. The valve body 4 is a disc-shaped butterfly valve, and is fixed to the valve shaft 3 with screws or the like.

  The speed reduction mechanism 5 includes a pinion gear 9 mounted on the output shaft of the motor 2, a large-diameter gear 11 that meshes with the gear 10 of the pinion gear 9, and a middle gear that coaxially includes a small-diameter gear 12 that is smaller in diameter than the large-diameter gear 11. The reduction gear 13 includes a gear 14 that meshes with the small-diameter gear 12, and includes a rotating body 15 that is fixed to one end of the valve shaft 3 by caulking or the like.

  Here, the rotator 15 is made of a resin such as polyamide, and is provided in a ring shape by injection molding. The rotator 15 has a gear 14 at a part of the outer peripheral edge 19. A magnet 21 and a yoke 22 constituting a part of 6 are insert-molded. A return spring 24 that urges the valve shaft 3 and the valve body 4 in a direction to return to the rotation angle at the time of engine idling is mounted between the rotating body 15 and the body 23.

  The rotation angle detection device 6 has a Hall element 27 that is fixed so as to face the magnet 21 and the yoke 22 in the axial direction. The rotation of the magnet 21 and the yoke 22 together with the valve shaft 3 makes the Hall element 27 feel sensitive. Magnetic flux density changes. Then, the rotation angle detection device 6 detects the rotation angle of the valve shaft 3 by outputting an electric signal corresponding to the magnetic flux density that the Hall element 27 senses to the ECU.

[Features of Example 1]
According to the valve device 1 of the first embodiment, as shown in FIG. 3, the magnet 21 and the yoke 22 constituting the rotation angle detection device 6 are each divided into two bodies. That is, along the inner peripheral edge 20 of the rotating body 15, the magnet 21A, the yoke 22A, the magnet 21B, and the yoke 22B are insert-molded and held so as to sequentially contact in the circumferential direction.

  Here, the magnets 21 </ b> A and 21 </ b> B are provided in the same prismatic shape, and are held so that the longitudinal direction of the magnets 21 </ b> A and 21 </ b> B is parallel to the axial direction and the magnetization direction coincides with the circumferential direction of the rotating body 15. (Refer to FIG. 1 regarding the axial direction). Here, one circumferential end of the magnet 21A and the other circumferential end of the magnet 21B are magnetized to the N pole, and the other circumferential end of the magnet 21A and one circumferential end of the magnet 21B are magnetized to the S pole. ing.

  Further, the yokes 22A and 22B are provided as the same cylindrical divided body obtained by dividing a cylindrical body having a thickness in the radial direction along the axial direction, and the side surfaces 29 of the magnets 21A and 21B are provided at both ends in the circumferential direction. A contact surface 30 that contacts the surface.

  The magnets 21A and 21B are arranged in line symmetry with the axis 31 of the valve shaft 3 as the axis of symmetry, and the yokes 22A and 22B are arranged so as to sandwich the magnets 21A and 21B in the circumferential direction. That is, the side surface 29 on the N pole side of the magnet 21A is in contact with the contact surface 30 at the other circumferential end of the yoke 22B, and the side surface 29 on the S pole side of the magnet 21A is in contact with the one end in the circumferential direction of the yoke 22A. It is in contact with. Further, the side surface 29 on the N pole side of the magnet 21B is in contact with the contact surface 30 at one end in the circumferential direction of the yoke 22B, and the side surface 29 on the S pole side in the magnet 21B is in contact with the other end in the circumferential direction of the yoke 22A. It is in contact with.

  As a result, a magnetic flux directed in a direction parallel to the magnetization direction of the magnets 21 </ b> A and 21 </ b> B is formed on the axis 31. Further, a straight line that is perpendicular to the direction of the magnetic flux and passes through the axial center 31 (hereinafter, the straight line 32 is referred to as an axial magnetic flux orthogonal line 32) passes through the magnets 21A and 21B.

Magnets 21 </ b> A and 21 </ b> B are arranged such that axial magnetic flux orthogonal line 32 points in the middle of a circumferential direction setting range of gear 14 (hereinafter referred to as gear setting range 33). For example, the magnets 21 </ b> A and 21 </ b> B are formed by a straight line 34 that connects one end in the circumferential direction of the gear setting range 33 and the axis 31, and a straight line 35 that connects the other end in the circumferential direction of the gear setting range 33 and the axis 31. The angle is arranged so that the axial magnetic flux orthogonal line 32 bisects the angle.
The gear 14, the magnets 21A and 21B, and the yokes 22A and 22B are at the same position in the axial direction.

  Furthermore, a rotation restricting portion 36 for restricting the rotation of the rotating body 15 protrudes from the outer peripheral edge 19 to the outer peripheral side. The rotation restricting portion 36 is provided in a circumferential range where the gear 14 is not provided (hereinafter referred to as a gear non-setting range 37). And the magnet 21 </ b> A.

[Effect of Example 1]
According to the valve device 1 of the first embodiment, an annular plate-like resin-made rotating body 15 is attached to one end of the valve shaft 3, and via the gear 14 provided on the outer peripheral edge 19 of the rotating body 15, The output of the motor 2 is transmitted to the valve shaft 3. In addition, two magnets 21A and 21B for detecting the rotation angle of the valve shaft 3 are held along the inner peripheral edge 20 of the rotating body 15, and the magnets 21A and 21B are symmetrical about the axis 31 of the valve shaft 3. Are arranged in line symmetry. An axis magnetic flux orthogonal line 32 perpendicular to the direction of the magnetic flux formed on the axis 31 and passing through the axis 31 is directed to the middle of the gear setting range 33.
Thereby, even when the magnets 21A, 21B and the like are pulled and displaced by the inner peripheral edge 20 due to the thermal expansion of the rotating body 15, the loss of symmetry of the magnetic field formed by the magnets 21A, 21B is suppressed.

  That is, when the annular plate-shaped rotating body 15 is provided by resin molding, the inner and outer peripheral edges 20 and 19 are expanded in diameter by thermal expansion and displaced to the outer peripheral side, and the ring width (the outer peripheral diameter and the inner peripheral diameter The difference is also enlarged. The tensile force acting on the magnets 21A, 21B, etc. is stronger in the gear setting range 33 having a larger ring width than in the gear non-setting range 37 having a smaller ring width. In the gear setting range 33, the larger the circumferential distance from the gear non-setting range 37, that is, the middle of the gear setting range 33, the larger the inner peripheral edge 20 is, and the stronger the tensile force is.

  Therefore, the magnets 21 </ b> A and 21 </ b> B are arranged on the inner peripheral edge 20 so that the axial magnetic flux orthogonal line 32 is oriented in the middle of the gear setting range 33. That is, the direction of the axial magnetic flux orthogonal line 32 is matched with the direction in which the tensile force acts most strongly. As a result, the magnetic field can be translated in the direction in which the tensile force is most strongly applied, with minimal loss of symmetry. For this reason, even if magnet 21A, 21B is pulled by the inner periphery 20, it can suppress that the symmetry of a magnetic field is impaired.

  The magnets 21A and 21B are provided in a columnar shape and are held so that their longitudinal directions are parallel to the axial direction, and are sandwiched in the circumferential direction by yokes 22A and 22B provided as cylindrical divided bodies. A magnetic flux directed in a direction parallel to the magnetization direction of the magnets 21A and 21B is formed on the shaft 31. A straight line connecting the magnets 21A and 21B coincides with the shaft magnetic flux orthogonal line 32 and is in the gear setting range. It is oriented in the middle of 33.

  Thereby, the magnets 21 </ b> A and 21 </ b> B are arranged in the direction and the position where the tensile force due to the thermal expansion of the rotating body 15 acts most strongly. For this reason, variation in the displacement direction of the magnets 21A and 21B and the yokes 22A and 22B due to thermal expansion is suppressed, and the magnets 21A and 21B and the yokes 22A and 22B are kept in the same direction while maintaining the relative positional relationship before the displacement. It is displaced to. As a result, the possibility that an air gap is generated due to thermal expansion between the magnet 21A and the yokes 22A and 22B and between the magnet 21B and the yokes 22A and 22B is reduced, and further damage to the symmetry of the magnetic field is suppressed. .

The gear 14, the magnets 21 </ b> A and 21 </ b> B, and the yokes 22 </ b> A and 22 </ b> B are in the same position with respect to the axial direction of the valve shaft 3.
As a result, all components of the tensile force of the inner peripheral edge 20 act on the magnets 21A and 21B and the yokes 22A and 22B without generating a component force. For this reason, the magnets 21A, 21B and the yokes 22A, 22B are more strongly pulled by the inner peripheral edge 20 and displaced in the same direction while maintaining the contact before displacement. As a result, it is possible to further reduce the possibility of air gaps occurring between the magnet 21A and the yokes 22A and 22B and between the magnet 21B and the yokes 22A and 22B.

  According to the valve device 1 of the second embodiment, as illustrated in FIG. 4, only the magnets 21 </ b> A and 21 </ b> B are disposed on the inner peripheral edge 20 of the rotating body 15, and the yokes 22 </ b> A and 22 </ b> B are not disposed. The magnets 21A and 21B are provided as identical cylindrical cylinders having a thickness in the radial direction, and are held so that their outer peripheral edges follow the inner peripheral edge 20, and the two columnar gaps 41 are opposed to each other in the circumferential direction. Form.

The center of the outer peripheral edge of the magnet 21A and the center of the inner peripheral edge of the magnet 21B are magnetized to the N pole, and the center of the inner peripheral edge of the magnet 21A and the center of the outer peripheral edge of the magnet 21B are magnetized to the S pole. Has been.
As a result, a magnetic flux directed in a direction parallel to the magnetization direction of the magnets 21 </ b> A and 21 </ b> B is formed on the axial center 31, and the axial magnetic flux orthogonal line 32 passes through the two columnar gaps 41.

  Further, the magnets 21 </ b> A and 21 </ b> B are arranged so that the axial magnetic flux orthogonal line 32 is directed in the middle of the gear setting range 33. For example, the magnets 21 </ b> A and 21 </ b> B are formed by a straight line 34 that connects one end in the circumferential direction of the gear setting range 33 and the axis 31, and a straight line 35 that connects the other end in the circumferential direction of the gear setting range 33 and the axis 31. The angle is arranged so that the axial magnetic flux orthogonal line 32 bisects the angle.

  As described above, both circumferential ends of the magnets 21 </ b> A and 21 </ b> B are arranged in the direction and position where the tensile force due to the thermal expansion of the rotating body 15 acts most strongly. For this reason, variation in the displacement direction of the magnets 21A and 21B due to thermal expansion is suppressed, and the magnets 21A and 21B are displaced in the same direction while maintaining the relative positional relationship before the displacement. As a result, the possibility that the two columnar gaps 41 expand due to thermal expansion is reduced, and further damage to the symmetry of the magnetic field is suppressed.

The gear 14 and the magnets 21A and 21B are at the same position in the axial direction.
As a result, the tensile force of the inner peripheral edge 20 causes all components to act on the magnets 21A and 21B without generating a component force. For this reason, the magnets 21A and 21B are more strongly pulled by the inner peripheral edge 20 and displaced in the same direction while maintaining the relative positional relationship before the displacement. For this reason, the possibility that the two columnar gaps 41 may be further reduced.

[Modification]
According to the valve device 1 of the first and second embodiments, the magnets 21 </ b> A and 21 </ b> B include the straight line 34 connecting the circumferential end of the gear setting range 33 and the shaft center 31, and the other circumferential end of the gear setting range 33 and the shaft center. Although the angle formed by the straight line 35 connecting to 31 is arranged so that the axial magnetic flux orthogonal line 32 is equally divided into two, the thermal expansion of the rotating body 15 causes significant damage to the symmetry of the magnetic field. The positions of the magnets 21A and 22B are not limited to such a mode as long as they are not. In other words, the middle of the gear setting range 33 means a position where no significant damage occurs in the symmetry of the magnetic field due to the thermal expansion of the rotating body 15.

Further, according to the valve device 1 of the first embodiment, the gear 14, the magnets 21A and 21B, and the yokes 22A and 22B are in the same position with respect to the axial direction of the valve shaft 3, but the gear 14 and the magnet 21A, 21B and yokes 22A and 22B may be shifted in the axial direction. For example, the gear 14 may be shifted closer to the valve body 4 than the magnets 21A and 21B and the yokes 22A and 22B, that is, toward the other end in the axial direction.
Similarly, in the valve device 1 according to the second embodiment, the gear 14 and the magnets 21A and 21B may be shifted in the axial direction.

  Further, the valve device 1 of the first embodiment is applied to a throttle device and drives a valve body 4 as a throttle valve. However, the valve device 1 is applied to drive valves other than the throttle valve. Also good. For example, the valve device 1 may be applied to a device that drives a tumble swirl control valve that switches the flow path of intake air in an intake manifold or a device that drives an EGR valve for returning a part of exhaust gas to intake air. Good.

(Example 1) which is sectional drawing of a valve apparatus. It is an internal side view of a valve apparatus (Example 1). (A) is principal part explanatory drawing which shows arrangement | positioning of the rotary body, magnet, and yoke before thermal expansion, (b) is principal part explanatory drawing which shows arrangement | positioning of the rotary body, magnet, and yoke after thermal expansion ( Example 1). (A) is principal part explanatory drawing which shows arrangement | positioning of the rotary body and magnet before thermal expansion, (b) is principal part explanatory drawing which shows arrangement | positioning of the rotary body and magnet after thermal expansion (Example 2). . (A) is principal part explanatory drawing which shows arrangement | positioning of the rotary body before a thermal expansion, a magnet, and a yoke, (b) is principal part explanatory drawing which shows arrangement | positioning of the rotary body after thermal expansion, a magnet, and a yoke ( Conventional example). (A) is principal part explanatory drawing which shows arrangement | positioning of the rotary body and magnet before thermal expansion, (b) is principal part explanatory drawing which shows arrangement | positioning of the rotary body and magnet after thermal expansion (conventional example).

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Valve apparatus 2 Motor 3 Valve shaft 14 Gear 15 Rotating body 19 Outer peripheral edge 20 Inner peripheral edge 21 Magnet 22 Yoke 31 Axis (axis of valve axis)
32 Axis of magnetic flux orthogonal line (Line that is perpendicular to the direction of magnetic flux formed on the axis of the valve axis and passes through the axis of the valve axis, line that connects two magnets, line that connects two columnar gaps)
33 Gear setting range (Gear circumferential setting range)
41 Columnar gap

Claims (5)

In the valve device that decelerates the output of the motor and transmits it to the valve shaft, and drives the valve shaft by the decelerated output,
An annular plate-shaped resin-made rotating body that is attached to one axial end of the valve shaft and rotates with the valve shaft;
A gear is provided on a part of the outer peripheral edge of the rotating body, and the reduced output is transmitted to the valve shaft via the gear,
Two magnets for detecting the rotation angle of the valve shaft are held along the inner periphery of the rotating body,
The two magnets are arranged in line symmetry with the axis of the valve shaft as a symmetry axis to form a magnetic flux on the axis of the valve shaft,
A valve characterized in that a straight line passing through the axis of the valve shaft that is perpendicular to the direction of the magnetic flux formed on the axis of the valve shaft is directed to the middle of the circumferential setting range of the gear. apparatus. The valve device according to claim 1,
The two magnets are provided in a columnar shape and are held so that their longitudinal direction is parallel to the axial direction, and are sandwiched in the circumferential direction by two yokes held along the inner peripheral edge of the rotating body. ,
Of the two magnets, one circumferential end of one magnet and the other circumferential end of the other magnet are magnetized to the same polarity, and the other circumferential end of one magnet and the circumferential direction of the other magnet One end is magnetized to the same polarity,
The straight line connecting the two magnets is directed to the middle of the circumferential setting range of the gear. The valve device according to claim 2,
The valve device, wherein the gear, the two magnets, and the two yokes are in the same position in the axial direction. The valve device according to claim 1,
The two magnets are provided in a split cylindrical body having a thickness in the radial direction, and are held so that their outer peripheral edges are along the inner peripheral edge of the rotating body, and form two columnar gaps facing each other in the circumferential direction. ,
Of the two magnets, the center of the inner peripheral edge of one magnet is magnetized with a different polarity from the center of the inner peripheral edge of the other magnet,
The valve device characterized in that a straight line connecting the two columnar gaps is oriented in the middle of a circumferential setting range of the gear. The valve device according to claim 4,
The valve device, wherein the gear and the two magnets are in the same position in the axial direction.

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