Rotary Solenoid

Abstract

To promote energy conservation by reducing power consumption, suppress heat generation, stabilize rotational torque characteristics, and suppress an impact force generated at a time of a stop at an end terminal to improve the overall durability.SOLUTION: An inner surface 2mi of a yoke body 2m and magnetically connected surfaces 2cpo, 2cqo of core parts 2cp, 2cq are magnetically connected with each other through a void portion Gs. In addition, a gap Lg of the void portion Gs is set so that a rate of variation of an overall rotatable torque Tr as of when energized in a rotation angle range Zr of a magnet rotor part Mr, being ±15[°] with respect to a rotational torque Tr at a central position Xc of the rotation angle range Zr with respect to a rotational torque Tr as of when energized at the central position Xc of the rotation angle range Zr that is set with respect to the magnet rotor part Mr, is within 20[%].SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a rotary solenoid that displaces a magnet rotor section within a predetermined rotational angle range by passing current through a stator section. [Background technology]

[0002] Conventionally, as rotary solenoids comprising a cylindrical yoke main body, a pair of core portions protruding from the inner peripheral surface of the yoke main body toward the center at 180° opposite each other, a stator portion having coil portions wound around each core portion, and a magnet rotor portion supported for free rotation at the center position of the end face portion of the casing portion, there are known the solenoid disclosed in Patent Document 1 and the rotary solenoid device disclosed in Patent Document 2.

[0003] The solenoid in Document 1 is a solenoid comprising a cylindrical casing, an end cover that closes the opening of the casing, a coil bobbin housed in the casing, one or more coils wound around the coil bobbin, one or more pin terminals that are attached to the coil bobbin and connect the wire ends leading out from the coil, and a movable part having a magnet that is displaced when electricity is passed through the coil. In particular, the solenoid is configured with a through hole portion provided in the coil bobbin, and a pin terminal that has an intermediate mounting portion that, when inserted into one end opening of the through hole portion, can stop the wire end at an intermediate position where it can be connected to the wire connection portion and at a final position where the wire connection portion is shielded by a barrier portion in the coil bobbin, and has a pin main body portion that protrudes from the other end opening of the through hole portion in the final position.

[0004] Furthermore, the rotary solenoid device in the same document 2 aims to make the entire device small and compact, eliminating the problem of unnecessary installation space being taken up, and reducing the number of parts to reduce costs and improve ease of assembly. Specifically, in a rotary solenoid device configured by attaching an acting member to the shaft of a rotary solenoid body, the acting member is formed from a plate material, a restricting hole portion is provided in this plate material, and a restricting protrusion portion is provided on one end face of the rotary solenoid body that engages with the restricting hole portion to restrict the rotational displacement range of the acting member. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2012-39804 A [Patent Document 2] JP 2001-258233 A Summary of the Invention [Problem to be solved by the invention]

[0006] However, in the above-mentioned conventional rotary solenoid, the yoke part constituting the stator is composed of a pair of core parts that protrude from the inner peripheral surface of the cylindrical yoke main body in the direction of the center at 180° opposite each other, and the yoke main body and the core parts are closely attached (or integrally formed) to reduce magnetic resistance. Therefore, the rotational torque characteristics tend to be low at start-up and high at end, which resulted in the following problems to be solved:

[0007] First, the voltage used by a rotary solenoid depends on the low rotational torque of the magnet rotor when it is started. Therefore, it is necessary to set the applied voltage high to compensate for the rotational torque, which is an obstacle to promoting energy conservation, and is also a factor in the generation of heat in the rotary solenoid and in the instability of the rotational torque characteristics.

[0008] Secondly, since the rotational torque of the rotary solenoid tends to be high at the end, the acceleration of the magnet rotor near the end becomes large. Therefore, when the end stops, a large impact force is generated, and depending on the size of the load and the structure of the stopper mechanism, the reaction force caused by this impact force is transmitted to the stator part via the magnet rotor and bearings, which becomes a factor in reducing the durability of the entire rotary solenoid.

[0009] SUMMARY OF THE PRESENT EMBODIMENT An object of the present invention is to provide a rotary solenoid that solves the problems existing in the background art. [Means for solving the problem]

[0010] In order to solve the above-mentioned problems, the rotary solenoid 1 of the present invention is configured to include a cylindrical yoke body 2m, a pair of core portions 2cp, 2cq protruding from an inner circumferential surface 2mi of the yoke body 2m toward the center at an angle of 180°, a stator portion Ms having coil portions 3p, 3q wound around each of the core portions 2cp, 2cq, and a magnet rotor portion Mr supported for free rotation at the center of end surface portions 4s, 4t of a casing portion 4, in which the inner circumferential surface 2mi of the yoke body 2m and the magnetic connection surfaces 2cpo, 2cqo of the core portions 2cp, 2cq are magnetically connected via a gap Gs, and the spacing Lg of the gap Gs is set so that the rate of variation of the overall rotational torque Tr when current is applied within a rotational angle range Zr of ±15°, relative to the rotational torque Tr when current is applied at a central position Xc of the rotational angle range Zr set for the magnet rotor portion Mr, is within 20%.

[0011] In this case, according to a preferred embodiment of the invention, the coil portions 3p, 3q can be wound around the coil bobbins 11p, 11q attached to the outer casings of the core portions 2cp, 2cq. The gaps Gs can be formed by selecting the positions where the core portions 2cp, 2cq are fixed by the coil bobbins 11p, 11q, and the gaps Gs can be filled with the synthetic resin material R that forms the coil bobbins 11p, 11q to provide filled resin portions 11fp, 11fq. Furthermore, a stopper mechanism 12 can be provided that limits the rotation angle range Zr of the magnet rotor portion Mr to within ±15°. Effect of the Invention

[0012] The rotary solenoid 1 according to the present invention having such a configuration provides the following remarkable effects.

[0013] (1) The inner peripheral surface 2mi of the yoke body 2m and the magnetic connection surfaces 2cpo, 2cqo of the core portions 2cp, 2cq are magnetically connected via a gap Gs, and the spacing Lg of the gap Gs is set so that the rate of fluctuation of the overall rotational torque Tr when current is applied in a rotational angle range Zr of ±15° with respect to the rotational torque Tr when current is applied at the center position Xc of the rotational angle range Zr set for the magnet rotor portion Mr is within 20%, so that the rotational torque characteristics when current is applied in the rotational angle range Zr of the magnet rotor portion Mr can be made flat with reduced fluctuations. This makes it possible to set a low applied voltage at startup, promoting energy savings by reducing power consumption, suppressing heat generation, and stabilizing the rotational torque characteristics.

[0014] (2) The rotational torque Tr at the end of the rotary solenoid 1 can be set low, so the acceleration of the magnet rotor portion Mr near the end can be reduced. As a result, the impact force generated when the end stops can be suppressed, and the reaction force accompanying this impact force can be reduced from being transmitted to the stator portion Ms via the magnet rotor portion Mr and the end face portions 4s, 4t having the bearing holes, so the durability of the entire rotary solenoid 1 can be improved.

[0015] (3) In a preferred embodiment, when forming the coil portions 3p, 3q, they are wound around coil bobbins 11p, 11q that are attached to the outer casing of the core portions 2cp, 2cq. In addition to the inherent insulating function of insulating the core portions 2cp, 2cq from the coil portions 3p, 3q, positioning can be reliably performed by interposing the gap portion Gs between the yoke main body portion 2m and the core portions 2cp, 2cq, making it easy to obtain a highly reliable rotary solenoid 1.

[0016] (4) In a preferred embodiment, the gap Gs is formed by selecting a position where the core portions 2cp, 2cq are fixed by the coil bobbins 11p, 11q. This can be accommodated by changing the shape of the coil bobbins 11p, 11q, and therefore a highly accurate gap Gs can be easily formed.

[0017] (5) In a preferred embodiment, the synthetic resin material R that forms the coil bobbins 11p, 11q is filled into the gap Gs to provide filled resin portions 11fp, 11fq. This allows the coil bobbins 11p, 11q to be molded together by insert molding, etc., so that the spacing Lg of the gap Gs can be stably maintained and the gap Gs can be easily molded as part of the coil bobbins 11p, 11q without changing the mold, etc.

[0018] (6) In a preferred embodiment, by providing a stopper mechanism 12 that limits the rotation angle range Zr of the magnet rotor portion Mr to within ±15°, the rotation angle range Zr can be set to within ±15°, at least from the practical standpoint, so that a rotary solenoid 1 that reliably achieves the effects of the present invention can be obtained. [Brief description of the drawings]

[0019] [Figure 1] FIG. 2 is a cross-sectional rear view including an enlarged cross-sectional view of a part of a rotary solenoid according to a preferred embodiment of the present invention; [Diagram 2] FIG. 2 is a cross-sectional plan view of the rotary solenoid; [Diagram 3]FIG. 3 is a side view of the coil bobbin of the rotary solenoid as viewed from above in FIG. 2; [Figure 4] FIG. 2 is a graph showing the rotational torque characteristic versus the rotation angle range when current is applied, with the gap of the rotary solenoid as a parameter. [Diagram 5] FIG. 2 is a graph showing the rotation angle range vs. rotation torque characteristics when the rotary solenoid is not energized, with the gap width of the rotary solenoid as a parameter; [Figure 6] 2 is a magnetic flux diagram of the rotary solenoid at start-up; [Figure 7] 1 is a magnetic flux diagram of a rotary solenoid according to the prior art at start-up; [Figure 8] FIG. 2 is a characteristic diagram of a rotational torque versus rotation angle range (±15°) of a rotary solenoid according to a preferred embodiment of the present invention; [Figure 9] FIG. 2 is an enlarged sectional front view showing a modified example of the rotary solenoid; [Figure 10] FIG. 1 is a cross-sectional front view including an enlarged cross-sectional view of a part of a rotary solenoid according to a conventional technique; DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0020] Next, preferred embodiments of the present invention will be described in detail with reference to the drawings.

[0021] First, in order to facilitate understanding of the rotary solenoid 1 according to this embodiment, a schematic configuration of a general rotary solenoid 1r shown in FIG. 10 will be described as a comparative example.

[0022] The rotary solenoid 1r includes, as its main components, a yoke main body 2m, core portions 2cp and 2cq, coil portions 3p and 3q, a casing portion 4, a magnet rotor portion Mr, and coil bobbins 11p and 11q.

[0023] In this case, as shown in Fig. 10, a cylindrical yoke body 2m, a pair of core portions 2cp, 2cq protruding toward the center from an inner peripheral surface 2mi of the yoke body 2m, and coil portions 3p, 3q wound around each of the core portions 2cp, 2cq constitute a stator portion Ms. Since the yoke body 2m constitutes a part of a casing portion 4, the casing portion 4 is composed of the yoke body 2m, a front end cover 4s (see Fig. 2) that closes a front end opening of the yoke body 2m, and a rear end cover 4t (see Fig. 2) that closes a rear end opening of the yoke body 2m.

[0024] Furthermore, a pair of core portions 2cp, 2cq protruding from the inner peripheral surface 2mi of the yoke main body 2m toward the center at an angle of 180° constitute the yoke portion 2. Since the yoke portion 2 constitutes a magnetic circuit through which magnetic flux passes, magnetic loss is typically minimized by forming the inner peripheral surface 2mi of the yoke main body 2m and the magnetic connection surfaces 2cpo, 2cqo of the core portions 2cp, 2cq in close contact (0 mm) or integrally, as shown in the partially extracted and enlarged cross-sectional view of FIG.

[0025] Meanwhile, the front side of the magnet rotor part Mr is rotatably supported at the center position of the front end cover 4s, and the rear side of the magnet rotor part Mr is rotatably supported at the center position of the rear end cover 4t. A magnet 5m is provided at the middle position of the magnet rotor part Mr, with its N pole and S pole magnetized at a position 180° opposite each other in the radial direction, and a stopper mechanism 12 that restricts the rotation angle range of the magnet rotor part Mr to a predetermined angle range is provided near the front end of the magnet rotor part Mr located outside the casing part 4. The stopper mechanism 12 is made up of a lever-shaped stopper 12s having one end fixed to the magnet rotor part Mr, and a pair of restriction parts 12p, 12q arranged on one and the other side that restrict the rotation angle range of the stopper 12s.

[0026] As a result, when current is passed through the coil portions 3p, 3q in the forward direction, north and south poles are generated in each of the core portions 2cp, 2cq, the south pole (north pole) of the magnet 5m is attracted (repelled) by the north pole (north pole) of each of the core portions 2cp, 2cq, and the stopper 12s comes into contact with one of the regulating portions 12p and stops due to the rotational displacement of the magnet rotor portion Mr, and when current is passed through the coil portions 3p, 3q in the reverse direction, south and north poles are generated in each of the core portions 2cp, 2cq, the north pole (south pole) of the magnet 5m is attracted (repelled) by the south pole (north pole) of each of the core portions 2cp, 2cq, and the stopper 12s comes into contact with the other regulating portion 12q due to the rotational displacement of the magnet rotor portion Mr.

[0027] Next, the overall configuration of the rotary solenoid 1 according to this embodiment will be specifically described with reference to FIGS.

[0028] The basic component configuration of the rotary solenoid 1 is the same as that of a general rotary solenoid 1r shown as a comparative example in Fig. 10. For this reason, the same parts in the rotary solenoid 1 as those in Fig. 10 are given the same reference numerals to clarify the configuration.

[0029] Like the rotary solenoid 1r, the rotary solenoid 1 also comprises, as its main components, a yoke body portion 2m, core portions 2cp, 2cq, coil portions 3p, 3q, a casing portion 4, a magnet rotor portion Mr, and coil bobbins 11p, 11q.

[0030] In this case, the casing portion 4 includes a yoke main body portion 2m formed in a cylindrical shape, a front end cover (end surface portion) 4s attached to the front end opening of the yoke main body portion 2m, and a rear end cover (end surface portion) 4t attached to the rear end opening of the yoke main body portion 2m. Therefore, as described above, the yoke main body portion 2m serves as a part of the casing portion 4 in addition to the original function of the yoke main body portion 2m. The yoke main body portion 2m is formed in a cylindrical shape using a carbon steel material or the like. As shown in FIG. 2, the front end cover 4s is fitted into the front end opening of the yoke main body portion 2m to close it, so the entire front end cover 4s is integrally formed in a disk shape, and the rear end cover 4r is also fitted into the rear end opening of the yoke main body portion 2m to close it, so the entire rear end cover 4r is integrally formed in a disk shape.

[0031] Furthermore, a bearing hole 21 that supports the front side of the drive shaft 5s in the magnet rotor part Mr, which will be described later, is provided at the center of the front end cover 4s, and a bearing hole 22 that supports the rear side of the drive shaft 5s in the magnet rotor part Mr, is provided at the center of the rear end cover 4t. Since the front end cover 4s and the rear end cover 4t are required to have a bearing function and an insulating function, respectively, they are desirably formed from a lubricating resin material that has insulating properties, heat resistance, and high slidability.

[0032] On the other hand, a pair of core portions 2cp, 2cq protruding from an inner peripheral surface 2mi of the yoke main body 2m toward the center at 180° opposite each other are provided, and at least the yoke main body 2m and the pair of core portions 2cp, 2cq are prepared as three independent components. According to the present invention, the inner peripheral surface 2mi of the yoke main body 2m and the magnetic connection surfaces 2cpo, 2cqo of the core portions 2cp, 2cq are magnetically connected via a gap Gs, as shown in Figures 1 and 2. In this case, coil bobbins 11p, 11q made of a synthetic resin material R are attached to the outer peripheries of the pair of core portions 2cp, 2cq, and the coil portions 3p, 3q are wound around the coil bobbins 11p, 11q. Further, the coil bobbins 11p, 11q located on the magnetic connection surfaces 2cpo, 2cqo of the core portions 2cp, 2cq opposing the inner peripheral surface 2mi of the yoke body 2m are formed to extend along the inner peripheral surface 2mi of the yoke body 2m.

[0033] At this time, since the tip portion of the coil bobbin 11p located at the tip of the core portion 2cp and the tip portion of the coil bobbin 11q located at the tip of the core portion 2cq are close to each other, the tip portion of the coil bobbin 11p and the tip portion of the coil bobbin 11q are integrally formed via the connecting piece portions 11jp, 11jq, respectively, and the step portion formed by the connecting piece portions 11jp, 11jq has a positioning function of abutting against the tips of the core portions 2cp, 2cq. As a result, the coil bobbins 11p and 11q can be integrally molded as a continuous bobbin unit 11 as a whole. It is preferable that the bobbin unit 11 is integrally formed as a whole from a highly flame-retardant insulating synthetic resin material (for example, syndiotactic polystyrene, etc.).

[0034] As a result, the core portions 2cp, 2cq are attached to the bobbin unit 11 or assembled by insert molding, and in this state, the magnet wire W, such as a copper wire, can be wound around each of the coil bobbins 11q, 11q using an automatic winding machine. In this way, when forming the coil portions 3p, 3q, if the coil portions 3p, 3q are formed by winding the wire around the coil bobbins 11p, 11q attached to the outer casings of the core portions 2cp, 2cq, in addition to the inherent insulating function of insulating the core portions 2cp, 2cq from the coil portions 3p, 3q, positioning can be reliably performed with the gap portion Gs between the yoke main body 2m and the core portions 2cp, 2cq interposed therebetween, so that a highly reliable rotary solenoid 1 can be easily obtained.

[0035] The bobbin unit 11 in this state can be inserted directly into the yoke body 2m and assembled. When assembled, as shown in FIG. 1, the outer surfaces of the four almost equally spaced outer periphery portions of the bobbin unit 11 in the circumferential direction come into surface contact with the inner circumferential surface 2mi of the yoke body 2m, and the bobbin unit 11 is positioned in the radial direction. Furthermore, the above-mentioned shapes of the connecting pieces 11jp, 11jq and the coil bobbins 11p, 11q allow the bobbin unit 11 to be positioned in the radial direction relative to the core portions 2cp, 2cq, so that the spacing Lg of the gaps Gs can be easily set. In this way, if the gaps Gs are formed by selecting the positions at which the core portions 2cp, 2cq are fixed by the coil bobbins 11p, 11q, the gaps Gs can be easily formed because the gaps Gs can be easily formed with high accuracy since the gaps Gs can be adjusted by changing the shapes of the coil bobbins 11p, 11q.

[0036] The gap Gs may be formed simply as an air space, but may also be formed as filled resin portions 11fp, 11fq by filling synthetic resin material R forming the coil bobbins 11p, 11q as shown in Figs. 1 to 3. In this way, if the gap Gs is filled with synthetic resin material R forming the coil bobbins 11p, 11q to provide filled resin portions 11fp, 11fq, the gap Gs can be molded together with the coil bobbins 11p, 11q by insert molding or the like, so that the gap Gs can be stably maintained at a distance Lg and can be easily molded as a part of the coil bobbins 11p, 11q without changing the mold or the like. In this manner, the stator portion Ms can be configured.

[0037] On the other hand, the magnet rotor section Mr includes a drive shaft 5s made of a magnetic material such as stainless steel, and a cylindrical magnet 5m fixed to the middle of the drive shaft 5s. The magnet 5m is a two-pole magnet with an S pole and an N pole magnetized at 180° opposing positions in the radial direction. As shown in Figures 1 and 2, the front side of the drive shaft 5s is rotatably supported by a bearing hole 21 provided in the center of the front-end cover 4s, and the rear side of the drive shaft 5s is rotatably supported by a bearing hole 22 provided in the center of the rear-end cover 4t.

[0038] In addition, a stopper mechanism 12 similar to that shown in the rotary solenoid 1r in FIG. 10 is provided near the front end of the magnet rotor part Mr located outside the casing part 4. That is, the stopper mechanism 12 has a function of restricting the rotation angle range of the magnet rotor part Mr to a predetermined angle range, and is composed of a lever-shaped stopper 12s having one end fixed to the magnet rotor part Mr, and a pair of restricting parts 12p, 12q arranged on one side and the other side of the stopper 12s for restricting the rotation angle range. In particular, the stopper mechanism (12) in FIG. 1 sets the rotation angle range Zr of the magnet rotor part Mr to ±15°. In this way, by providing the stopper mechanism 12 that restricts the rotation angle range Zr of the magnet rotor part Mr to within ±15°, the rotation angle range Zr can be set to within ±15° at least from the viewpoint of implementation, so that a rotary solenoid 1 with a reliable function and effect of the present invention can be obtained.

[0039] Next, the gap Gs, which is a main component of the rotary solenoid 1 according to this embodiment, will be specifically described with reference to FIGS.

[0040] As mentioned above, in this type of rotary solenoid, magnetic loss is typically reduced by closely contacting or forming integrally between the inner surface 2mi of the yoke main body portion 2m and the magnetic connection surfaces 2cpo, 2cqo of the core portions 2cp, 2cq.

[0041] On the other hand, there is room for improvement in terms of optimizing the magnetic properties (rotational torque properties) for a certain purpose. Therefore, this time, we verified the effect of the presence or absence of the gap Gs, and confirmed that the rotational torque Tr can be optimized in terms of energy saving and durability by selecting the spacing Lg of the gap Gs in particular.

[0042] First, the effect of the presence or absence of the gap Gs was verified. This verification was performed by simulation. In Fig. 4, the distance Lg of the gap Gs of the rotary solenoid 1 was set as a parameter, i.e., the distance Lg [mm] was set as "0.1", "0.2", "0.3", "0.4", and "0.5", and the torque value of the rotation torque Tr [Nm] was obtained in the rotation angle range "-90 to +90 [°]" at the time of the drive current of 0.5 [A] for each distance Lg. In Fig. 5, the distance Lg [mm] of the gap Gs of the rotary solenoid 1 was set as "0.1", "0.2", "0.3", "0.4", and "0.5", and the value of the rotation torque Tr [Nm] was obtained in the rotation angle range "-90 to +90 [°]" at the time of non-energization (0 [A]) for each distance Lg. As is clear from Figures 4 and 5, when the spacing Lg of the gap Gs is set to 0.2 mm, and the rotation angle range Zr is within the range of -15 to +15 degrees, it can be confirmed that flat characteristics can be maintained both when a current of 0.5 A is applied and when it is not applied.

[0043] On the other hand, Fig. 6 shows the magnetic flux lines f... of the rotary solenoid 1 when using the gap Gs with an optimum distance Lg of 0.2 mm, and Fig. 7 shows the magnetic flux lines f of the rotary solenoid 1r of the prior art (distance Lg is 0 mm). In both cases, the magnetic flux lines f are shown at the time of startup (current flow of 0.5 A) at an angle of -15°.

[0044] Thus, the verification results confirmed that the interval Lg of the gap Gs can be optimized as the gap Gs specific to the rotary solenoid 1, and in particular, the torque characteristic of the rotational torque Tr with respect to the rotation angle range Zr can be made flat. That is, in the case of a general (conventional) rotary solenoid, the flow of magnetic flux is mainly from the magnet 5m (N pole) → core part 2cp → yoke main body part 2m → core part 2cq → magnet 5m (S pole) as shown in FIG. 7, and some magnetic flux leaks outside the yoke main body part 2m, but in the rotary solenoid 1 provided with the gap Gs (magnetic resistance), the amount of magnetic flux flowing from the magnet 5m (N pole) → core part 2cp → core part 2cq → magnet 5m (S pole) can be increased as shown in FIG. 6. This makes it possible to balance the magnetic flux flowing between the yoke main body part 2ms and the core parts 2cp and 2cq, making it possible to eliminate the inclination of the rotational torque due to the holding force, and it is assumed that the rotational torque Tr when energized can be made flat.

[0045] 1 to 3 show a rotary solenoid 1 according to this embodiment, which was prototyped based on the results of such verification. The rotational torque characteristics of this rotary solenoid 1 are shown in FIG. 8. The rotational angle range Zr of this rotary solenoid 1 was set to ±15° to optimize the rotational torque characteristics. That is, when setting the gap Lg of the gap Gs, the fluctuation rate of the overall rotational torque Tr when current is applied in the rotational angle range Zr of ±15°, relative to the rotational torque Tr when current is applied at the center position Xc of the rotational angle range Zr set for the magnet rotor part Mr, was set to be within 20%. In this case, the gap Lg of the gap Gs was about 0.06 mm.

[0046] As a result, in the illustrated example, as shown in Fig. 8, when 11 [V] and 15 [V] are applied to the rotary solenoid 1 shown as the present invention, it can be confirmed that the fluctuation rate is within 10 [%] both at startup (non-saturation) and at temperature saturation. The fluctuation rate is a value calculated by [(Tru-Trd) / Trc] x 100 [%], where the rotation angle range Zr is set to ±15 [°], the rotation torque at +15 [°] is Tru, the rotation torque at -15 [°] is Trd, and the central value of the rotation angle range Zr, i.e., the rotation torque at 0 [°] which is the central position Xc, is Trc. The fluctuation rate at startup (non-saturation) when 15 [V] is applied to the rotary solenoid 1r shown as a comparative example (prior art) is 62 [%].

[0047] In the case of the rotary solenoid 1 according to this embodiment, when the rotation angle range Zr is set to ±15° and started from one end side, the rotation torque Tr at start-up is about 2.3 times, the rotation torque Tr at the center position Xc is about 1.5 times, and the rotation torque Tru at the end is about 1.2 times. In addition, when the rotation torque Tr at start-up is set to the same value, the applied power to obtain the same response speed when the rotation angle range Zr is set to ±6° is -80%. Furthermore, when the rotation torque Tr at start-up is the same, the power consumption is -70% and when the rotation torque Tr at the end is the same, the power consumption is -25%. A reduction in impact force can be confirmed, and high durability can be expected. In addition, the temperature rise is reduced by about 20°C. According to Arrhenius' law, the life is four times longer.

[0048] Therefore, according to the rotary solenoid 1 of this embodiment, as a basic configuration, the inner peripheral surface 2mi of the yoke main body 2m and the magnetic connection surfaces 2cpo, 2cqo of the cores 2cp, 2cq are magnetically connected through the gap Gs, and the interval Lg of the gap Gs is set so that the fluctuation rate of the entire rotation torque Tr when energized in the rotation angle range Zr of ±15° with respect to the rotation torque Tr when energized at the center position Xc of the rotation angle range Zr set for the magnet rotor part Mr is within 20%, so that the rotation torque characteristic when energized in the rotation angle range Zr of the magnet rotor part Mr can be made flat with suppressed fluctuation. As a result, the applied voltage at the time of startup can be set low, energy saving can be promoted by reducing power consumption, heat generation can be suppressed, and the rotation torque characteristic can be stabilized. In addition, the rotation torque Tr at the end of the rotary solenoid 1 can be set low, so that the acceleration of the magnet rotor part Mr near the end can be reduced. As a result, the impact force generated when the terminal end stops can be suppressed, and the reaction force associated with this impact force can be reduced from being transmitted to the stator portion Ms via the magnet rotor portion Mr and the end face portions 4s, 4t having the bearing hole portions, thereby improving the durability of the entire rotary solenoid 1.

[0049] Although the preferred embodiment has been described in detail above, the present invention is not limited to such an embodiment. The present invention is not limited to the above, and the detailed configuration, shape, material, quantity, numerical values, etc. can be changed, added, or deleted as desired without departing from the spirit of the present invention.

[0050] For example, as shown in FIG. 9 as a modified example, a gap adjustment mechanism 31 that can adjust the size of the gap Lg of the gap Gs may be provided. In this case, the manufacturing by insert molding is not performed. That is, the core parts 2cp, 2cq and the bobbin unit 11 are manufactured as separate parts and integrated by assembly. For this reason, the gap Gs is configured by filling it with an air space Sg or an elastic material. In addition, a screw hole 32 is formed through the part of the yoke body part 2m facing the magnetic connection surface 2cpo of the core part 2cp (2cq is the same), and an adjustment screw 33 is screwed into this screw hole 32, and the tip surface abuts against the magnetic connection surface 2cpo. Furthermore, it is possible to configure by interposing elastic materials 34, 34 such as rubber between the core part 2cp and the bobbin unit 11. This configuration is not necessary when the gap Gs is filled with an elastic material. At least one gap adjustment mechanism 31 can be provided, but two or more gap adjustment mechanisms 31 may be provided at positions that take balance into consideration, as necessary. Such a modification is one example, and it is also possible to adjust the gap Gs by inserting a thin sheet material into the gap Gs, or by other methods.

[0051] In addition, in the present invention, the pair of core parts 2cp, 2cq protruding from the inner peripheral surface 2mi of the yoke main body 2m toward the center at 180° opposite each other means one set, and does not exclude the case where two or more sets are included. Also, the fact that the rate of fluctuation of the overall rotational torque Tr when current is applied in a rotational angle range Zr of ±15° with respect to the rotational torque Tr at the center position Xc of the rotational angle range Zr of the magnet rotor part Mr is within 20% is merely a condition at the time of setting, and is not a condition at the time of use (implementation). Furthermore, the coil bobbins 11p, 11q are not necessarily essential components, and can be replaced by other members having insulating functions. [Industrial Applicability]

[0052] The rotary solenoid according to the present invention can be used in various types of rotary solenoids that have a function of displacing a magnet rotor portion within a predetermined rotational angle range by passing current through a stator portion. [Explanation of symbols]

[0053] 1: rotary solenoid, 2m: yoke body, 2mi: inner surface of yoke body, 2cp: core, 2cq: core, 2cpo: magnetic connection surface, 2cqo: magnetic connection surface, 3p: coil, 3q: coil, 4: casing, 4s: end surface, 4t: end surface, 11p: coil bobbin, 11q: coil bobbin, 11fp: filled resin, 11fq: filled resin, 12: stopper mechanism, Ms: stator, Mr: magnet rotor, Gs: gap, Lg: gap spacing, Zr: rotation angle range, Xc: center position, Tr: rotation torque, R: synthetic resin material

Claims

1. A rotary solenoid comprising a cylindrical yoke main body, a pair of core portions protruding from the inner circumferential surface of the yoke main body at an angle of 180° toward the center, a stator portion having coil portions wound around each of the core portions, and a magnet rotor portion rotatably supported at the center position of an end face portion of a casing portion, wherein the inner circumferential surface of the yoke main body and the magnetic connection surface of the core portions are magnetically connected via a gap, and the spacing of the gap is set so that the rate of variation of the overall rotational torque when current is applied within a rotational angle range of ±15° relative to the rotational torque when current is applied at the center position of the rotational angle range set for the magnet rotor portion is within 20%.

2. 2. The rotary solenoid according to claim 1, wherein the coil portion is wound around a coil bobbin that is attached to the outer casing of the core portion.

3. 3. The rotary solenoid according to claim 2, wherein the gap is formed by selecting a position where the core portion is fixed by the coil bobbin.

4. 4. The rotary solenoid according to claim 2, wherein the gap is filled with a synthetic resin material that forms the coil bobbin to provide a filled resin portion.

5. 2. The rotary solenoid according to claim 1, further comprising a stopper mechanism for restricting the rotation angle range of said magnet rotor portion to within ±15°.

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