JP6088237B2 - Geared motor and valve drive device - Google Patents

Description

  The present invention relates to a rotating member that rotates when power of the motor is transmitted, a geared motor that includes means for detecting the rotational position of the rotating member, and a valve driving device that uses such a geared motor.

  As a geared motor provided with means for detecting the rotational position of such a rotating member, a geared motor described in Patent Document 1 is known. In this geared motor, a magnet (magnetic body) is fixed to a rotating member (output member), and the rotational position of the rotating member is detected by detecting the fixed magnet.

JP 2010-233446 A

  However, since the geared motor of Patent Document 1 has a configuration in which the magnet is loosely fitted in the hole formed in the rotating member, variations occur in the fixing position of the magnet, and the detection accuracy of the rotating position of the rotating member is accordingly increased. It will decline. Further, even in a configuration in which the magnet is sandwiched between two tongue pieces 145 described as a modification in FIG. 6 of Patent Document 1, one tongue piece 145 is deformed more greatly than the other, and the fixed position of the magnet. Variation will occur.

  In view of the above problems, the present invention improves the detection accuracy of a rotational position in a geared motor including a rotating member whose rotational position is detected by a fixed magnet and a valve driving device using such a geared motor. For the purpose.

In order to solve the above-described problems, a geared motor according to the present invention is a rotating member that is rotated by the power of the motor, a magnet that is inserted into a holding hole formed in the rotating member, and a magnet that detects the magnet. Or a detecting means that has a plurality of detecting members and obtains the rotational position of the rotating member by detecting the magnet by the detecting member, and the rotating member is located on one side of the rotating direction of the rotating member. A plurality of deformed portions having different projecting directions from the inner wall surface of the holding hole are formed, and the deformed portion is deformed by the magnet inserted into the holding hole, and the magnet is on the other side in the rotation direction of the rotating member. The gist of the present invention is that it is in contact with the inner wall surface of the holding hole.

  According to the present invention, the magnet comes into contact with the inner wall surface located on the opposite side (the other side in the rotational direction) of the deforming portion by the reaction force generated by the deformation of the deforming portion. That is, since the magnet is positioned with reference to this inner wall surface, the positioning accuracy of the rotating member (positioning accuracy in the rotating direction of the rotating member) is increased, and the rotational position detection accuracy of the rotating member is improved.

Further, if a plurality of deforming portions having different projecting directions are formed, the magnet is pressed against the inner wall surface located on the other side in the rotational direction in a state where forces in different directions are transmitted to the magnet. The positioning accuracy can be improved not only in the rotating direction of the rotating member but also in the radial direction of the rotating member.

  The magnet may be in contact with the inner wall surface of the holding hole located on the other side in the rotation direction of the rotating member at a plurality of locations, and the tangent lines at the plurality of locations where the magnet and the inner wall surface are in contact with each other.

  According to the above configuration, the magnet is pressed so as to come into contact with the inner wall surface located on the other side in the rotation direction in a plurality of different directions, so that the magnet positioning accuracy is not limited to the rotation direction of the rotation member. It can also be improved in the radial direction.

  In addition, when the rotation member rotates to one side, the detection unit is set to detect the magnet by the detection member to obtain the rotation position of the rotation member. When the magnet rotates, the side of the magnet that contacts the inner wall surface of the holding hole enters the detection range of the detection member before the side of the magnet that contacts the deformed portion. Just do it.

  The rotating member includes a first magnet detected by the detection member when the rotating member is rotated in one direction and a detection member detected when the rotating member is rotated in the other direction. In any case when the second magnet is fixed and the rotating member is rotated in one direction or the other, the side in contact with the inner wall surface of the holding hole in the magnet is in the magnet. What is necessary is just to be comprised so that it may approach into the detection range of the said detection member before the side which contacts the said deformation | transformation part.

  The first magnet is detected by a first detection member that is one of the detection members, and the second magnet is detected by a second detection member that is a detection member different from the first detection member. It only has to be configured.

  As described above, the magnets detected by the first detection member and the magnets detected by the second detection member are different magnets, so that the second magnet is moved from the rotational position of the rotation member detected by the first detection member. The rotation angle of the rotation member up to the rotation position of the rotation member detected by the second detection member may be set to a different angle from the first detection member to the second detection member around the rotation center of the rotation member. it can. For this reason, the freedom degree of the arrangement position of a 1st detection member and a 2nd detection member improves.

  The rotating member includes a substrate on which the first detection member and the second detection member are mounted, the rotating member is opposed to an end surface on the output side of the motor, and a terminal of the motor is connected to the substrate. Just do it.

  According to the above configuration, since the rotating member can be disposed close to the end face on the output side of the motor, the size of the geared motor in the axial direction of the rotating member can be reduced. In this case, the positions where the first detection member and the second detection member can be arranged need to avoid the end face on the motor output side and the connection position between the motor terminal and the substrate. Since the magnets detected by the two detection members are different magnets, the rotation position of the rotation member detected by the second detection member from the rotation position of the rotation member detected by the first detection member by the first magnet. The rotation angle of the rotation member up to can be different from the angle from the first detection member to the second detection member around the rotation center of the rotation member.

  A valve driving device comprising the geared motor, wherein a valve connected to the rotating member is driven by the power of the motor to change and output the mixing ratio of one fluid to the other fluid. The position at which the second magnet is detected by the first detection member is set so that only the one fluid is output, and the position at which the first magnet is detected by the second detection member is the other position. The valve drive device may be set so that only the fluid is output.

  According to the above configuration, it is possible to provide a valve drive device that can accurately detect a state in which only one fluid is output and a state in which only the other fluid is output.

  If it is set so that the side of the magnet that contacts the deformed portion first enters the detection range of the detection member, the detection accuracy may be reduced due to variations in the size of the magnet. Accordingly, since the side of the magnet that comes into contact with the inner wall surface of the holding hole first enters the detection range of the detection member, the influence of such a dimensional variation in the magnet can be reduced.

  The holding hole may be a bottomed hole having an insertion port on the side opposite to the side where the detection member is installed.

  With such a configuration, the positioning accuracy in the axial direction of the magnet (the rotational axis direction of the rotating member) is improved.

  Further, it is only necessary that the periphery of the insertion port in the rotating member is melted and the magnet is sandwiched between the melted portion and the bottom of the holding hole in the magnet insertion direction.

  Even when the magnet is prevented from falling off by melting the periphery of the insertion port by such heat and closing the opening, the positioning accuracy of the magnet in the rotational direction and the axial direction is not affected.

  Moreover, the said deformation | transformation part should just be formed in the bottom side in the inner wall face of the said holding hole.

  Thus, if the deformation | transformation part is formed in the bottom side, insertion of a magnet is easy. Further, even if the insertion is facilitated in this way, the positioning accuracy on the bottom side near the detection member does not decrease, so the detection accuracy by the detection means does not decrease.

  Further, the magnet is in contact with each of the two deformed portions located on one side of the rotating member, and is in contact with the inner wall surface of the holding hole located on the other side of the rotating member in two directions. Just do it.

  Further, the two locations where the magnet contacts each of the two deformable portions and the two locations where the magnet contacts the inner wall surface of the holding hole located on the other side in the rotation direction of the rotating member are centered on the magnet. It suffices if it is located at a point symmetry position as a symmetry point.

  With such a configuration, since the magnet is sandwiched at the opposing position, the magnet is less likely to be displaced in the plane direction orthogonal to the axial direction.

  Further, two locations where the magnet contacts each of the two deformable portions and two locations where the magnet contacts the inner wall surface of the holding hole located on the other side in the rotation direction of the rotating member are The shortest distance from the center of rotation to the circle passing through the center of the magnet may be equal.

  In this way, in the radial direction of the rotating member, the component of the force by which one deformed portion pushes the magnet cancels out the component of the force by which the other deformed portion pushes the magnet. That is, since the sum of the forces acting on the magnet in the radial direction of the rotating member becomes 0, the magnet can be prevented from shifting in the radial direction.

  The magnet may be a sintered magnet.

  The size of the sintered magnet changes due to sintering. Even a sintered magnet having variations in external dimensions can be accurately positioned.

  According to the present invention, since the positioning accuracy of the magnet with respect to the rotating member is improved, the detection accuracy of the rotational position of the rotating member by the detecting means (detecting member) is excellent.

It is an exploded view of the geared motor concerning the embodiment of the present invention. It is a top view of a rotation member. It is sectional drawing (the AA sectional view taken on the line of FIG. 2) of the holding hole formed in the rotation member. 4A is an enlarged view of the holding hole, FIG. 4B is a view showing a state in which the magnet is inserted into the holding hole, and FIG. 4C is a state in which the protruding portion is melted and held. It shows a state where the opening of the hole is blocked. It is a top view of a board | substrate and the detection member mounted in it. It is the figure which showed the positional relationship of the holding member formed in the rotation member, and the detection member mounted in the board | substrate. It is an external view of a lower case. It is the figure which showed the positional relationship of the rotation direction of a rotation member, the magnet (inner wall surface which a magnet contacts) hold | maintained at the holding hole, and a detection member. It should be noted that the protruding portion is actually melted and the magnet is not exposed, but for the sake of explanation, the protruding portion is not melted and the magnet is exposed.

  An embodiment of the present invention will be described in detail with reference to FIGS. The geared motor 1 according to the embodiment of the present invention includes a detection unit having a rotating member 10, a magnet 20, and a detection member 30. Hereinafter, each configuration and other configurations will be described. In addition, the axial direction (height direction) in the following description means a direction along the rotational axis direction of the rotating member 10, and the upper case 91 side is the upper (high) and the lower case 92 side is the lower (low). . Further, the surface direction means a surface direction orthogonal to the axial direction.

  The rotating member 10 is a thermoplastic synthetic resin member that is rotated by the power of the motor 40 that is a motor. The rotating member 10 is rotatably supported by a bearing portion 921 (see FIGS. 1 and 7) whose shaft portion (not shown) is formed in the lower case 92. The geared motor 1 according to the present embodiment uses a motor 40 that is a stepping motor as a drive source. The motor gear 401 that rotates integrally with the output shaft (rotor) of the motor 40 meshes with the large-diameter tooth portion of the first wheel 41. The small-diameter tooth portion of the first wheel 41 is meshed with the large-diameter tooth portion of the center wheel & pinion 42. The small diameter tooth portion of the center wheel & pinion 42 is meshed with the gear portion 11 of the rotating member 10. When the motor 40 rotates, the power is transmitted to the rotating member 10 via the first wheel 41 and the second wheel 42. The rotating member 10 has an output portion 12 positioned outside the case through a through hole 911 formed in the upper case 91 that is one of cases accommodating each component member. A driving object (not shown) is connected directly or indirectly (via a connecting member or the like) to the output unit 12. That is, the power transmitted to the output unit 12 is transmitted to an external driving object. An example of the drive symmetrical object is a valve for adjusting the flow rate of the water heater (adjusting the mixing ratio of hot water and water). In addition, the output part 12 is formed with a D-cut 121 and a spline 122, which are engaged with a driving object or a connecting member, at different positions in the axial direction. The relative position in the rotation direction of the output unit 12 and the member engaged therewith can be aligned with high accuracy by the spline 122. Further, it is possible to prevent the spline 122 and the portion engaged with the spline 122 from being shifted (shifted by several teeth) and engaged by the D-cut 121.

  The magnet 20 (see FIG. 4) is fixed in a state of being inserted into the holding hole 13 formed in the rotating member 10. In the present embodiment, two magnets 20 (first magnet 21 and second magnet 22) that are sintered magnets are fixed to the rotating member 10. The shape of the holding hole 13 (a method for positioning the magnet 20 with respect to the rotating member 10) will be described later. When the rotating member 10 rotates, the magnet 20 fixed to the rotating member 10 moves along a circle centered on the rotation center of the rotating member 10. In the present embodiment, the first magnet 21 and the second magnet 22 are equidistant from the rotation center of the rotating member 10.

  The detection means is an electrical element provided on the substrate 50 that has one or a plurality of detection members 30 (for example, Hall ICs) and receives signals from the detection members 30. In the present embodiment, two detection members 30 (a first detection member 31 and a second detection member 32) are mounted on the substrate 50. Both detection members 30 are provided at positions that overlap in the axial direction with a locus (circle) drawn by the magnet 20 (holding hole 13) when the rotating member 10 rotates (see FIG. 6). The substrate 50 is positioned by passing a plurality of positioning protrusions 922 (see FIGS. 1 and 7) formed on the lower case 92 through positioning holes 53 (see FIG. 5) formed on the substrate 50. That is, since both the bearing portion 921 that supports the rotating member 10 and the positioning projection 922 that positions the substrate 50 are formed on the lower case 92, the rotating member 10 and the substrate 50 are positioned by the bearing portion 921 and the positioning projection 922. By doing so, both the detection members 30 are positioned so as to overlap with the circle in the axial direction. One end side of the terminal pin 51 is connected to the substrate 50. The other end side of the terminal pin 51 is located inside the connector housing portion 923 formed in the lower case 92. The substrate 50 is electrically connected to the motor 40 via the motor connection pins 52. A power source and an external control device are electrically connected to the substrate 50 (control means) via a connector portion constituted by a connector housing portion 923 and terminal pins 51.

  When the rotation member 10 rotates and the distance between the magnet 20 and the detection member 30 becomes equal to or less than a predetermined distance, the detection unit obtains an ON signal from the detection member 30. Conversely, when the distance between the magnet 20 and the detection member 30 exceeds a predetermined distance, the detection means obtains an OFF signal (no signal) from the detection member 30. The detection means obtains the rotational position of the rotating member 10 based on the switching of the signal. Here, “obtaining the rotational position” not only refers to obtaining (calculating) a specific angle of the rotating member 10, but also whether the rotating member 10 has reached a reference position such as the original position, that is, This includes obtaining information that the rotating member 10 has rotated to a specific position. Further, in the present embodiment, it is defined that “the magnet 20 has entered the detection range of the detection member 30” when the signal is switched from OFF to ON.

  In this way, the detection means obtains the rotational position of the rotating member 10 depending on whether or not the magnet 20 is detected by the detecting member 30. Therefore, in order to accurately obtain the rotational position of the rotating member 10 by the detecting means (detecting member 30), it is important to accurately position the magnet 20 with respect to the rotating member 10. Hereinafter, the positioning of the magnet 20 will be described in detail.

  The rotating member 10 is formed with a holding hole 13 into which a columnar magnet 20 is inserted. As shown in FIGS. 3 and 4A, the holding hole 13 has a bottom 136 on the detection member 30 side (lower side), and the opposite side is opened (in a state where the magnet 20 is not fixed). It is a hole with a bottom. A through hole 137 smaller than the magnet 20 to be inserted (the magnet 20 cannot pass through) is formed in the bottom 136. When the magnet 20 is marked with a polarity mark, the polarity of the magnet 20 can be confirmed through the through-hole 137 even after the opening is closed by heat caulking, which will be described later. It is desirable that the holding hole 13 in which the magnet 20 is accommodated be separated from the center of the rotating member 10 as much as possible. This is to reduce the error when detecting the rotational position of the rotating member 10 as will be described later.

  The inner wall surface extending in the axial direction of the holding hole 13 has four surfaces 1331, 1332, 1341, and 1342 that are inclined with respect to the radial direction of the rotating member 10. Two of the four surfaces are located on one side in the rotational direction of the rotating member 10. Further, the inner wall surface 1331 and the inner wall surface 1342 and the inner wall surface 1332 and the inner wall surface 1341 face each other in parallel. The other two surfaces are located on the other side in the rotation direction of the rotating member 10. Here, one side or the other side in the rotation direction of the rotating member 10 means the rotation center of the rotating member 10 and the center C of the holding hole 13 (in the state where the columnar magnet 20 is inserted into the holding hole 13) 4 is defined as a boundary line (plane), which is connected to the center of the magnet 20. The straight line (plane) L shown in FIG. It shall mean the other side. In addition, “one side” and “the other side” refer to opposite directions, and do not specify a specific direction such as a left rotation direction or a right rotation direction.

  The two inner wall surfaces 1331 and 1332 located on one side in the rotation direction of the rotating member 10 are positioned in a substantially “V” shape. Specifically, it inclines in the direction where the space | interval of both wall surfaces gradually spreads toward the other side of the rotation direction of the rotation member 10. As shown in FIG. The shortest distances from both wall surfaces to the circle passing through the center C of the magnet 20 around the rotation center of the rotating member 10 (hereinafter, this circle may be simply referred to as “reference circle R”) are set to be equal. Yes. Therefore, a location where the two inner wall surfaces 1331 and 1332 (or a virtual surface obtained by extending the inner wall surfaces 1331 and 1332) intersect is located on the reference circle R. Deformed portions P (first deformed portion P1 and second deformed portion P2) that are protrusions projecting toward the hole (space) are formed from the two inner wall surfaces 1331 and 1332. Both deformation portions P are protrusions that can be plastically deformed by an external force. The shortest distance between the first deformable portion P1 and the reference circle R is set so that the shortest distance between the second deformable portion P2 and the reference circle R is equal. That is, the point where the straight line extending in the projecting direction of the first deformation part P1 and the second deformation part P2 (the straight line connecting the center of the tip of the protrusion and the center of the root part) intersects is located on the reference circle R. As described above, two deformed portions P having different projecting directions are formed on one side of the rotating member 10 in the rotating direction.

  Further, the deformed portion P is not formed over the entire vertical direction of the two inner wall surfaces 1331 and 1332 located on one side of the rotation direction of the rotating member 10, but the bottom 136 of the inner wall surfaces 1331 and 1332. It is formed on the side (see FIG. 3). That is, the length in the height direction of the deformed portion P extending upward from the bottom 136 of the holding hole 13 is set to be smaller than the height of the inner wall surfaces 1331 and 1332.

  On the other hand, two inner wall surfaces 1341 and 1342 (hereinafter, sometimes referred to as the first inner wall surface 1341 and the second inner wall surface 1342 separately) positioned on the other side in the rotation direction of the rotating member 10 are substantially “V”. "Located in a letter shape. Specifically, it inclines in the direction where the space | interval of both wall surfaces gradually spreads toward the one side of the rotation direction of the rotating member 10. As shown in FIG. The shortest distance from both wall surfaces to the reference circle R is set to be equal. A location where two inner wall surfaces 1341 and 1342 (or virtual surfaces obtained by extending the inner wall surfaces 1341 and 1342) located on the other side in the rotation direction intersect is located on the reference circle R. The two inner wall surfaces 1341 and 1342 located on the other side in the rotation direction of the rotating member 10 are not formed with projections like the deformed portion P, and are flat surfaces. As described above, “the other side” means a direction opposite to the above “one side”, and does not specify a specific direction. That is, it is only necessary that the deformed portion P (inner wall surfaces 1331 and 1332 on which the deformed portion P is formed) is formed on one side in the rotation direction and the inner wall surfaces 1341 and 1342 on which the deformed portion P is not laid on the other side. .

  When the magnet 20 is inserted into the holding hole 13 having such a shape, the deformed portion P is pushed by the magnet 20 to be deformed (collapsed). The magnet 20 comes into contact with each of the first inner wall surface 1341 and the second inner wall surface 1342 located on the other side in the rotation direction of the rotating member 10 by the reaction force from the deformed deforming portion P. That is, the magnet 20 is in point contact with two deformable portions P and two inner wall surfaces 1341 and 1342 provided on the opposite side of the deformable portion P (at least four points (points M1 to M1 in FIG. 4B)). In the state of contact) indicated by M4). The two places where the magnet 20 is in contact with each of the two deformable portions P and the two places where the magnet 20 is in contact with each of the first inner wall surface 1341 and the second inner wall surface 1342 are centered on the center C of the magnet 20. Located in a point-symmetric position. Further, two tangents where the magnet 20 contacts each of the two deformable portions P and two tangents where the magnet 20 contacts each of the first inner wall surface 1341 and the second inner wall surface 1342 intersect each other. That is, the direction in which the first deforming portion P1 pushes the magnet 20 is different from the direction in which the second deforming portion P2 pushes the magnet 20, and the direction in which the magnet 20 pushes the first inner wall surface 1341 and the magnet 20 push the first inner wall surface 1341. Pushing direction The pushing direction of the second inner wall surface 1342 is different. Thus, since the magnet 20 is pushed by the deforming portion P and is in contact with each of the two inner wall surfaces 1341 and 1342 located on the other side in the rotation direction of the rotating member 10, these inner wall surfaces 1341 and 1342 are in contact with each other. This is a reference for positioning the magnet 20 in the surface direction.

  After the magnet 20 is inserted into the holding hole 13, the protruding portion 135 formed around the holding hole 13 is melted (the melted portion is indicated by 135 m in FIG. 4C). The opening is blocked. The magnet 20 is sandwiched between a portion that closes the opening formed by melting the protruding portion 135 and the bottom 136 of the holding hole 13. That is, the bottom 136 of the holding hole 13 is a reference for positioning the magnet 20 in the axial direction. The upper surface of the gear portion 11 (the surface on the side where the opening of the holding hole 13 is provided) is provided above the upper surface of the protruding portion. For this reason, the melted protruding portion 135 can prevent the gear portion 11 from flowing into the tooth portion.

  Two rotating holes 13 (a first holding hole 131 and a second holding hole 132) are formed in the rotating member 10 of the present embodiment, and the magnet 20 is fixed in both the holding holes 13. In the present embodiment, the rotation amount from the original position to the end position of the rotating member 10 is set to be less than one rotation (reciprocating between less than one rotation), and the first magnet 21 is mounted on the substrate. 50 detects the original position of the rotating member 10 (driving object) by detecting the first detection member 31 provided in 50, and the second detection member 32 provided in the substrate 50 detects the second magnet 22. Thus, the end position of the rotating member 10 (the driving object) is detected. Specifically, it is as follows.

  When the rotating member 10 rotates from the original position toward the terminal position, the first magnet 21 approaches the first detection member 31 provided on the substrate 50 as shown in FIG. At this time, in the first magnet 21, the side in contact with the first inner wall surface 1341 and the second inner wall surface 1342 provided on the opposite side of the deformed part P approaches the first detection member 31 first. In other words, the portions of the first magnet 21 that are in contact with the inner wall surfaces 1341 and 1342 that are the reference for positioning are first detected by the detection member 30. Similarly, when the rotating member 10 rotates from the terminal position toward the original position, the second magnet 22 approaches the second detection member 32 provided on the substrate 50 as shown in FIG. At this time, in the second magnet 22, the side in contact with the two inner wall surfaces 1341 and 1342 provided on the opposite side of the deformed portion P approaches the second detection member 32 first. That is, the second magnet 22 is also detected by the detection member 30 first in a portion in contact with the inner wall surfaces 1341 and 1342 which are the reference for positioning. Thus, when viewed in the rotational direction of the rotating member 10, the side where the deformed portion P is formed (the side where the first inner wall surface 1341 and the second inner wall surface 1342 are in contact with the magnet 20) is the first magnet. 21 is set differently (reversely) between the holding hole 13 into which the magnet 21 is inserted and the holding hole 13 into which the second magnet 22 is inserted, thereby contacting the first inner wall surface 1341 and the second inner wall surface 1342 of the magnet 20. The detecting side is first detected by the detection member 30.

  When two rotational positions of the rotating member 10 such as the original position and the terminal position are detected, if two detection members 30 are installed, even if there is only one magnet 20 fixed to the rotating member 10, the two One rotational position can be detected. However, in this embodiment, two magnets 20 are provided, and each of the two magnets 20 is detected by the corresponding detection member 30. By doing in this way, both of the two magnets 20 provided on the rotating member 10 have portions with high positioning accuracy in contact with the first inner wall surface 1341 and the second inner wall surface 1342 which are reference surfaces first. The detection member 30 can be set to enter the detection range. In addition, if two magnets 20 are provided in this way, even if the difference in angle between the two rotational positions to be detected is 180 degrees (when the rotational position to be detected is set to be the farthest away), The detection member 30 can be placed close to the detection member 30. That is, the relative positional relationship in the rotation direction of one magnet 20 and one detection member 30 and the relative positional relationship in the rotation direction of the other magnet 20 and one detection member 30 Since it can be set as appropriate by adjusting the fixed position of the magnet 20, the detection member 30 is brought closer (the angle around the rotation member 10 is smaller than the difference between the two rotation positions to be detected). can do. Therefore, the degree of freedom in designing the substrate 50 is improved. If only one rotational position of the rotating member 10 needs to be detected, one detecting member 30 may be provided for one magnet 20. The portions of the two magnets 20 that are in contact with the first inner wall surface 1341 and the second inner wall surface 1342 may be detected by the one detection member 30 first.

  In addition, the size of the holding hole 13 needs to be a size that can be inserted even when the magnet 20 that is a sintered magnet is the largest, and when the variation range of the diameter of the magnet 20 is 0.1 mm When the magnet 20 is the smallest, it is necessary to provide a gap of 0.1 mm or more between the magnet 20 and the inner wall surface. When the distance from the center of the rotating member 10 to the center of the magnet 20 is 10 mm and the position of the magnet 20 is shifted by 0.1 mm in the circumferential direction, the angle at which the detecting member 30 detects the magnet 20 is about 0. It will shift by 6 degrees.

  The geared motor 1 according to the present embodiment having such a configuration is applied for driving a valve of a water heater that adjusts the mixing ratio of hot water and water, and the rotating member 10 is located at the original position (end position). When the output at the time is 100% water and the output when the rotating member 10 is located at the terminal position (original position) is 100% hot water, the output is at least 100% water and 100% hot water output. The state can be accurately controlled. The rotating member 10 may be formed with a degree that can stop the rotation of the rotating member 10 when a detection failure occurs due to an abnormality of the detecting member 30. Moreover, the rotating member 10 in which the holding hole 13 having the above-described shape is formed can be molded by a simple two-part mold (the rotating member 10 can have a shape without so-called undercut).

  According to the geared motor 1 according to the present embodiment described above, the following operational effects are exhibited.

  According to this embodiment, the magnet 20 causes the first inner wall surface 1341 and the second inner wall surface located on the opposite side (the other side in the rotational direction) of the deforming portion P due to the reaction force generated by the deformation of the deforming portion P. 1342 is brought into contact. That is, since the magnet 20 is positioned with reference to the inner wall surfaces 1341 and 1342, the positioning accuracy of the rotating member 10 in the rotating direction of the magnet 20 (positioning accuracy in the rotating direction of the rotating member 10) is increased. The detection accuracy is good.

  Moreover, the 1st deformation | transformation part P1 and the 2nd deformation | transformation part P2 from which a protrusion direction differs are formed, and the said magnet 20 is located in the other side of a rotation direction in the state which the force of a different direction was transmitted to the magnet 20. Since it is pressed against the wall surface 1341 and the second inner wall surface 1342, the positioning accuracy of the magnet 20 can be further improved.

  In addition, since the side of the magnet 20 that contacts the first inner wall surface 1341 and the second inner wall surface 1342 enters the detection range of the detection member 30 first, the detection accuracy decreases due to variations in the dimensions of the magnet 20. This can be suppressed.

  Further, since the periphery of the insertion port in the rotating member 10 is melted and the magnet 20 is sandwiched between the melted portion and the bottom 136 of the holding hole 13 in the insertion direction of the magnet 20, the magnet 20 in the axial direction is Excellent positioning accuracy. Further, even when the magnet 20 is prevented from falling off by melting the periphery of the insertion opening and closing the opening with such heat, the positioning accuracy of the magnet 20 in the rotational direction and the axial direction is not affected. .

  Moreover, since the deformation | transformation part P is formed in the bottom 136 side in the inner wall surfaces 1331 and 1332 of the holding hole 13, insertion of the magnet 20 is easy. Even if the insertion is facilitated in this way, the positioning accuracy on the bottom 136 side close to the detection member 30 does not decrease, and therefore the detection accuracy by the detection means does not decrease.

  Further, the magnet 20 is in contact with each of the two deformable portions P located on one side of the rotating member 10, and the inner wall surface (first inner wall surface 1341) of the holding hole 13 located on the other side in the rotation direction of the rotating member 10. And the second inner wall surface 1342) at two locations. And two places where magnet 20 contacts each of two deformation parts P, and two places where magnet 20 contacts inner wall surfaces 1341 and 1342 of holding hole 13 located in the other side of the rotation direction of rotating member 10, It is located at a point-symmetrical position with the center C of the magnet 20 as the symmetry point. In this way, since the magnet 20 is sandwiched between the opposing positions, the magnet 20 is less likely to be displaced in the plane direction orthogonal to the axial direction.

  Also, two locations where the magnet 20 contacts each of the two deformable portions P, and the inner wall surface (the first inner wall surface 1341 and the second inner wall) of the holding hole 13 where the magnet 20 is located on the other side in the rotation direction of the rotating member 10. The two locations in contact with the wall surface 1342) have the same shortest distance from the center of rotation of the rotating member 10 to the reference circle R passing through the center C of the magnet 20. Therefore, in the radial direction of the rotating member 10, the component of the force that the first deformable portion P <b> 1 pushes the magnet 20 and the component of the force that the second deformable portion P <b> 2 pushes the magnet 20 cancel each other. That is, since the sum of the forces acting on the magnet 20 in the radial direction of the rotating member 10 becomes zero, it is possible to suppress the magnet 20 from shifting in the radial direction.

  The holding hole 13 for holding the magnet 20 is provided on an output shaft that is directly or indirectly connected to the driving object (a driving object in a power transmission train from the motor (motor 40) to the driving object). Therefore, a reduction in detection accuracy due to backlash or the like can be suppressed.

  Although the embodiments of the present invention have been described in detail above, the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the gist of the present invention.

  The shape of the holding hole 13 is an example. A deformed portion protruding from the inner wall surface of the holding hole positioned on one side of the rotating member in the rotation direction is formed, and the magnet is positioned on the other side of the rotating member in the rotating direction due to a reaction force of the deformed portion deforming Any shape that contacts the inner wall surface of the hole may be used.

  In the said embodiment, although the magnet 20 was made into the column shape, it is good also as a prism shape. If the magnet 20 has a prismatic shape, the magnet 20 can be produced by cutting the plate-like magnet, so that the production cost of the magnet 20 can be reduced.

DESCRIPTION OF SYMBOLS 1 Geared motor 10 Rotating member 13 (131,132) Holding hole 1331,1332 Inner wall surface P (P1, P2) located in one side of rotation direction Deformation part 1341,1342 Inner wall surface 135 located in the other side of rotation direction 135m-shaped portion A portion in which the protruding portion that closes the opening of the holding hole is melted 136 Bottom 137 Through-hole 20 (21, 22) Magnet 30 (31, 32) Detection member 40 Motor (motor)
50 Substrate 91 Upper case 92 Lower case

Claims (14)

A rotating member that rotates when the power of the motor is transmitted;
A magnet inserted into a holding hole formed in the rotating member;
Detecting means for detecting one or more detection members for detecting the magnet, and obtaining the rotational position of the rotating member by detecting the magnet by the detecting member;
With
The rotating member is formed with a plurality of deforming portions having different projecting directions from an inner wall surface of the holding hole located on one side of the rotating direction of the rotating member, and the deforming portion is formed by the magnet inserted into the holding hole. In a state where the magnet is deformed, the magnet is in contact with the inner wall surface of the holding hole located on the other side in the rotational direction of the rotating member. The magnet is in contact with the inner wall surface of the holding hole located on the other side in the rotation direction of the rotating member at a plurality of locations, and tangent lines at the plurality of locations where the magnet and the inner wall surface are in contact with each other. The geared motor according to claim 1 . When the rotation member rotates in one direction, the detection means is set to detect the magnet by the detection member to obtain the rotation position of the rotation member.
When the rotating member rotates in one direction, the side of the magnet that contacts the inner wall surface of the holding hole enters the detection range of the detecting member before the side of the magnet that contacts the deformed portion. The geared motor according to claim 1 , wherein the geared motor is configured as described above. The rotating member includes a first magnet that is detected by the detecting member when the rotating member is rotated in one direction, and a first magnet that is detected by the detecting member when the rotating member is rotated in the other direction. Two magnets are fixed,
In either case when the rotating member is rotating in one direction or the other, the side of the magnet that contacts the inner wall surface of the holding hole is ahead of the side of the magnet that contacts the deformed portion. The geared motor according to claim 3 , wherein the geared motor is configured to enter a detection range of the detection member. The first magnet is detected by a first detection member that is one of the detection members, and the second magnet is detected by a second detection member that is a detection member different from the first detection member. The geared motor according to claim 4 , wherein the geared motor is provided. A substrate on which the first detection member and the second detection member are mounted;
The geared motor according to claim 5 , wherein the rotating member faces an output-side end face of the motor, and a terminal of the motor is connected to the substrate. A geared motor according to claim 5 or 6 is provided, and a valve connected to the rotating member is driven by power of the motor, thereby changing a mixing ratio of one fluid inputted and the other fluid. A valve driving device that outputs
The position where the first magnet is detected by the first detection member is set to a state where only the one fluid is output, and the position where the second magnet is detected by the second detection member is the other fluid. The valve drive device is characterized in that only the output is set. The geared motor according to any one of claims 1 to 7 , wherein the holding hole is a bottomed hole having an insertion port on a side opposite to a side on which the detection member is installed. The periphery of the insertion port in the rotating member is melted, and the magnet is sandwiched between the melted portion and the bottom of the holding hole in the magnet insertion direction. Item 9. The geared motor according to any one of Items 8 . The geared motor according to claim 9 , wherein the deforming portion is formed on a bottom side of an inner wall surface of the holding hole. The magnet is in contact with each of the two deformed portions located on one side of the rotating member, and is in contact with the inner wall surface of the holding hole located on the other side of the rotating direction of the rotating member at two locations. The geared motor according to any one of claims 1 to 10 , wherein: The two locations where the magnet contacts each of the two deformable portions and the two locations where the magnet contacts the inner wall surface of the holding hole located on the other side in the rotation direction of the rotating member are symmetrical about the center of the magnet. The geared motor according to claim 11 , wherein the geared motor is located at a point symmetrical position. Two locations where the magnet contacts the deformed portion and two locations where the magnet contacts the inner wall surface of the holding hole located on the other side in the rotation direction of the rotating member are centered on the rotation center of the rotating member. The geared motor according to claim 12 , wherein the shortest distance to a circle passing through the center of the magnet is equal. The geared motor according to any one of claims 1 to 13 , wherein the magnet is a sintered magnet.

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